Статті в журналах з теми "Liquid Blast Tube"

The combustion characteristics and emission from a gas turbine greatly depends on the spray characteristics. Pre-filming air-blast atomizers are commonly used in gas turbines due to their high spray cone angle and shorter atomization axial distance when compared to direct air-blast atomizers. Various numerical models are available in the open literature for predicting droplet characteristics. In the present study commercial code FLUENT 6.3 is used to predict the spray characteristics. The numerical results are validated against experimental results and further the spray characteristics in terms of radial Sauter mean diameter (SMD), mass flux distribution at varied axial distance and swirl number (S) have been discussed. The variation of predicted SMD with swirl number demonstrated a decrease in its value for each level of increase in the swirl number. Smaller droplets start to appear further downstream in addition to significant increase in radial spread of droplets. Negligible mass contribution from the smaller droplets at the boundary compared to that from bigger droplets at the centre was observed. Recessing the liquid tube at the exit of air nozzles showed a slight decrease in SMD. Recessing the liquid tube in the exit air nozzles results in a slight in SMD values, hence, the recessing of liquid post in the atomizer within certain limit might be beneficial not only helping in flame holding but also resulting in finer spray. The lessons learnt from this study on use of CFD for simulating the atomization process is highlighted.

DLR investigated forced combustion oscillations of two liquid fuel burners in a research combustion chamber at elevated pressures simulating idle conditions of aircraft engine combustors. The work was performed in collaboration with MTU Munich. An existing combustion chamber with optical access, capable to operate up to 20 bar, was upgraded with an air flow pulsator, that bypasses air from the combustor plenum to the exhaust with a sinusoidal massflow variation up to 700 Hz. Pressure transducers in the plenum and the flame tube monitored the forced disturbances. A photomultiplier recorded the OH* chemiluminescence of the flame. For the agreed operating conditions frequency scans of these values were registered. Additionally images of the OH* chemiluminescence were taken at selected frequencies and evaluated in a statistical manner, to separate turbulent and periodic behavior. From the analysis of the pressure data, it can be concluded, that serious thermoacoustic feedback was not observed for both burners. However, burner 2 with the flame detached from the wall exhibited a higher fluctuation level as burner 1 with the wall attached flame. A resonant behavior was observed near the characteristic frequency of the sound room comprised of plenum, flame tube, and burner nozzle as connecting passage. The chemiluminescence images show different modes of spatial fluctuation for the burners and for burner 2 they also vary with the operating condition.

Double skin composite (DSC) construction or Steel/concrete/steel sandwich construction (SCSS) is an innovative and relatively new form of composite construction that can be used in submerged tube tunnels, bridges deck, nuclear structures, liquid and gas containment structures, offshore and onshore structures, military shelters, and shear walls in buildings. The system consists of a plain concrete core sandwiched between two steel plates interconnected together by various types of mechanical shear connectors. The DSC construction perceives advantages that the external steel plates act as both formwork and primary reinforcement, and also as impermeable, blast and impact resistant membranes. The major duty of the shear connectors is to withstand longitudinal shear force and beam/slab separation, while in the bi-steel type where shear connectors are friction welded at both their two ends to two parallel steel plates, the longitudinal and transverse shear force, as well as plate buckling are resisted. The present paper highlights the previous prime researches concerning the subjects of SCSS composite construction, specifically on the conducted tests (push-out tests, tensile, direct shear tests, and bending tests) in which the components of partial interaction (uplift and slip forces) are resisted by various types of shear connectors.

OBJECT Blast-induced neurotrauma (BINT), if not fatal, is nonetheless potentially crippling. It can produce a wide array of acute symptoms in moderate-to-severe exposures, but mild BINT (mBINT) is characterized by the distinct absence of acute clinical abnormalities. The lack of observable indications for mBINT is particularly alarming, as these injuries have been linked to severe long-term psychiatric and degenerative neurological dysfunction. Although the long-term sequelae of BINT are extensively documented, the underlying mechanisms of injury remain poorly understood, impeding the development of diagnostic and treatment strategies. The primary goal of this research was to recapitulate primary mBINT in rodents in order to facilitate well-controlled, long-term investigations of blast-induced pathological neurological sequelae and identify potential mechanisms by which ongoing damage may occur postinjury. METHODS A validated, open-ended shock tube model was used to deliver blast overpressure (150 kPa) to anesthetized rats with body shielding and head fixation, simulating the protective effects of military-grade body armor and isolating a shock wave injury from confounding systemic injury responses, head acceleration, and other elements of explosive events. Evans Blue-labeled albumin was used to visualize blood-brain barrier (BBB) compromise at 4 hours postinjury. Iba1 staining was used to visualize activated microglia and infiltrating macrophages in areas of peak BBB compromise. Acrolein, a potent posttraumatic neurotoxin, was quantified in brain tissue by immunoblotting and in urine through liquid chromatography with tandem mass spectrometry at 1, 2, 3, and 5 days postinjury. Locomotor behavior, motor performance, and short-term memory were assessed with open field, rotarod, and novel object recognition (NOR) paradigms at 24 and 48 hours after the blast. RESULTS Average speed, maximum speed, and distance traveled in an open-field exploration paradigm did not show significant differences in performance between sham-injured and mBINT rats. Likewise, rats with mBINT did not exhibit deficits in maximum revolutions per minute or total run time in a rotarod paradigm. Short-term memory was also unaffected by mBINT in an NOR paradigm. Despite lacking observable motor or cognitive deficits in the acute term, blast-injured rats displayed brain acrolein levels that were significantly elevated for at least 5 days, and acrolein’s glutathione-reduced metabolite, 3-HPMA, was present in urine for 2 days after injury. Additionally, mBINT brain tissue demonstrated BBB damage 4 hours postinjury and colocalized neuroinflammatory changes 24 hours postinjury. CONCLUSIONS This model highlights mBINT’s potential for underlying detrimental physical and biochemical alterations despite the lack of apparent acute symptoms and, by recapitulating the human condition, represents an avenue for further examining the pathophysiology of mBINT. The sustained upregulation of acrolein for days after injury suggests that acrolein may be an upstream player potentiating ongoing postinjury damage and neuroinflammation. Ultimately, continued research with this model may lead to diagnostic and treatment mechanisms capable of preventing or reducing the severity of long-term neurological dysfunction following mBINT.

Vibrio vulnificus is a ubiquitous marine bacterium frequently isolated from shellfish and associated with severe and often fatal disease in humans. Various control strategies to reduce the disease risk associated with V. vulnificus contamination in shellfish have been proposed. However, evaluating the efficacy of these control strategies is complicated because of the difficulty in distinguishing V. vulnificus from the high levels of background environmental Vibrio spp. The purpose of this research was to develop a model indicator V. vulnificus strain that could be readily differentiated from background microflora and used to facilitate the evaluation of processing efficacy. A spontaneous nalidixic acid–resistant strain of V. vulnificus (Vv-NA) was prepared from a wild-type parent (Vv-WT) using selective plating techniques. Vv-NA was very similar to Vv-WT with respect to biochemical characteristics, appearance on selective plating media, detection limits using most probable number and polymerase chain reaction, and growth rate. In comparative freeze inactivation studies on pure cultures, Vv-WT and Vv-NA had similar freeze inactivation profiles at −20°C (conventional freezing), at −85°C (cold blast freezing), and in liquid nitrogen (cryogenic freezing). In oyster homogenates artificially inoculated with Vv-NA, the organism was inactivated 95 to 99% after freezing, irrespective of freezing temperature. Thermal inactivation comparisons of pure cultures of Vv-WT and Vv-NA using the capillary tube method revealed statistically significant differences in D values at 47°C (2.2 versus 3.0 min, respectively) and 50°C (0.83 versus 0.56 min, respectively), but nearly identical values at 52°C (0.21 versus 0.22 min, respectively). However, these D values were notably higher than those reported by other investigators and hence provided a conservative means by which to evaluate thermal inactivation. In oyster homogenates seeded with Vv-NA, D values of 1.3 ± 0.09 min and 0.41 ± 0.01 min were obtained at 46°C and 48°C, respectively. This study demonstrated that Vv-NA is readily enumerated and could be used as a surrogate for evaluating the degree of V. vulnificus inactivation provided by freezing and thermal treatments of oyster homogenates.

Boxwood (Buxus spp.) are commercially important evergreen ornamental plants with an annual market value of over $103 million in the United States. The recent U.S. incursion of boxwood blight disease caused by the fungus Calonectria pseudonaviculata (syn. Cylindrocladium pseudonaviculatum, Cy. buxicola) threatens the health and productivity of boxwood in both landscape plantings and nurseries. The first confirmed U.S. reports of the disease were made from Connecticut and North Carolina in November 2011 (2,4), followed by diagnoses in 10 additional states during 2012 and 2013. By August 2013, symptoms consistent with boxwood blight had been observed from B. sempervirens in Delaware, Maryland, New Jersey, and southeastern New York. Affected plants showed rapid onset of disease symptoms: dark brown to black spots or diffuse dark areas on leaves, followed by defoliation. Narrow, elongate black cankers also formed on current season shoots. Symptomatic stems and leaves were placed in petri dishes with moistened filter paper at 22°C for 3 days under continuous light. Conidiophores were excised, then placed on potato dextrose agar amended with streptomycin and neomycin (0.3 g/l). Resultant colonies showed dark brown pigmentation at the colony center surrounded by tan to reddish brown rings with white mycelia at the advancing edge. Conidia (n = 30 per isolate) were hyaline, cylindrical, rounded at both ends, with a single septum (45 to 76 × 4 to 6 μm; avg. 63 × 5 μm). Conidiophores (n = 20 per isolate) comprised a stipe, a hyaline septate stipe extension (length 119 to 192 μm; avg. 150 μm) and a terminal ellipsoidal vesicle (diameter 4 to 10 μm; avg. 7 μm). Based on morphological characteristics, the causal agent was identified as C. pseudonaviculata (1,4). Voucher specimens were deposited in the U.S. National Fungus Collections (BPI 892698 to 701). To verify morphological diagnosis, genomic DNA was extracted from fungal biomass grown in liquid cultures of yeast extract peptone dextrose media. A portion of the β-tubulin gene (TUB2) was PCR amplified and sequenced bi-directionally using primers Bta/Bt2b (3). BLASTn searches of NCBI GenBank databases using the TUB2 sequences (Accession Nos. KF785808 to 11) demonstrated 96 to 100% sequence identity with other C. pseudonaviculata isolates. To confirm pathogenicity, 5-month-old B. sempervirens and B. microphylla seedlings were spray-inoculated with a spore suspension of 1 × 104conidia/ml. One isolate from each state was independently tested with four replicates each. Non-inoculated water-sprayed plants served as negative controls. Plants were maintained in growth chambers at 22°C under constant light. Blight symptoms developed 4 to 5 days post inoculation. C. pseudonaviculata was re-isolated from inoculated plants; no symptoms or signs were observed from control plants. To our knowledge, this is the first report of C. pseudonaviculata in the states of Delaware, Maryland, New Jersey, and New York. This report demonstrates that C. pseudonaviculata is now widespread across the United States eastern seaboard, and represents a substantial threat to boxwood plants in North American landscapes and nurseries.References: (1) P. Crous et al. Sydowia 54:23, 2002. (2) D. F. Farr and A. Y. Rossman. Fungal Databases, USDA-ARS. Retrieved from http://nt.ars-grin.gov/fungaldatabases , 30 August 2013. (3) N. L. Glass and G. C. Donaldson. Appl. Environ. Microbiol. 61:1323, 1995. (4) K. L. Ivors et al. Plant Dis. 96:1070, 2012.

Introduction: There are numerous methods of isolating and detecting organisms that are similar and closely related; one of the most reliable method is molecular typing of 16S rRNA. Apart from being omnipresent as a multigene family, or operons; it is evolutionarily stable; the 16S rRNA gene (1,500 bp) is large enough for informatics purposes. Materials and Method: This study employed molecular sequencing of 16S rRNA by Sanger method to reveal the specific organisms’ nucleotides and blasting (BLASTn) to show the similarities between the resulting organisms and existing organisms. The 16S rRNA remains the best choice of identification process for bacteria because of its distinguishing sizes and evolutionary stability. Results: All isolates were Gram positive rods and were positive in Biochemical tests such as oxidase, catalase, citrate, and protease but were in turn negative in coagulase and indole test tests. On sensitivity test; 80% of all the isolates were resistant to common antibiotics except ciprofloxacin and ceftriaxone. Based on the sequence difference in the variable region (V1) of 16S rRNA as observed from the molecular sequencing results; four isolates out of ten were identified. Six were different strains of B cereus. Others isolates include: wiedmannii, thuringensis, toyonensis and pseudomycoides. Sequence analysis of the primer annealing sites showed that there is no clear‐cut difference in the conserved region of 16S rRNA, and in the gyrB gene, between B. cereus and B. thuringiensis strains. Phylogenetic analysis showed that four isolates showed high similarity to each other; hence the limited number of deletions when subjected to alignments by maximum neighborhood joining parsimony using MEGA X software. B. toyonensis, B. wiedmannii and thuringensis were distantly related. Introduction Authors Pathogens cause illness and death in some countries and it also causes infections and gastrointestinal diseases in other countries thereby causing public health concern. Pathogens are organisms capable of causing diseases. Reliable methods are needed for the detection of pathogens due to pathogen evolution as a result of new human habits or new industrial practices. Microbial classification of organisms ranges from genus to specie level depending upon the technique used either phenotypic or genotypic. Presently, molecular methods now obtain advances to allow utilization in microbiology [1]. There are numerous molecular methods which are of fast and simple application to the detection of pathogen. Among the pathogens involved in human health, Bacillus cereus is interesting due to their ability to survive in various habitats [2]. The genus Bacillus is aerobic or facultative anaerobic bacteria, gram positive spore forming rod shaped bacteria. Which can be characterized by two morphological forms, the vegetative cell which range from 1.02 to 1.2 um in width and from 3.0 to 5.0 in length, it can be straight or slightly curve, motile or non-motile, and the endospore (the non-swelling sporangium). The genus Bacillus is been characterized by the presence of endospore, which is not more than one per cell and they are resistant to many adverse environmental conditions such as heat, radiation, cold and disinfectants. It can also respire either in the presence or absence of oxygen [3]. Cell diameter of Bacillus cereus, sporangium and catalase test do not allow differentiation, where as important in differentiation among B. anthracis, B. cereus, B. thuringiensis can be considered by parasporal crystals and the presence of capsule. [4] Showed a B. thuringiensis strain capable of producing a capsule resembling that of B. anthracis. Most species of the genus display a great kind in physiological characteristics such as degradation of cellulose, starch, pectin, agar, hydrocarbons, production of enzymes and antibiotics and other characteristic such as acidophile, alkalinophile, psychrophile, and thermophile's which allows them to adapt to various environmental conditions [5]. In differentiating between species of the genus Bacillus it was difficult at early attempts when endospore formation and aerobic respiration were the main character used for classification. As reported by many authors that at molecular method level, the differentiation between B. thuringiensis and B. cereus is also very difficult. cereus can survive at the temperature between 4°c and 55°c. The mesophile strains can grow between the temperature of 10°c and 42°c, while psychotropic strains can survive at 4°c, whereas other strains are able to grow at 52 to 55°c. B. cereus vegetative cells grow at pH between 1.0 and 5.2. Heat resistant strain can survive and multiply in wet low acid foods in temperature ranging from 5 to 52°c. The survivability of B. cereus spores at 95°c decreases when the pH level decreases from 6.2 to 4.7 [6]. B. cereus can grow in the presence of salt with concentration up to 7.5% depending on the pH value. thuringiensis possesses a protein crystal that is toxic to insects. This toxin protein was first known as parasporal crystalline inclusion but was later referred to as π - endotoxin or in other ways known as insecticidal crystal protein [7]. Strains of B. thuringiensis bacteria possess a wide range of specificity in various orders of insects such as Lepidoptera, dipteral, coleoptera. These strains of bacteria produce crystalline proteins known as cry protein during sporulation. When B. thuringiensis infects an insects, it will cause the insect to loose appetite, enhances slow movement and over time the insect will die due to crystals of proteins that have been dissolved in the insect's stomach. In the cultivation of vegetable crops, the plant can be attack by many types of pests. Hence, in overcoming pest attacks farmers often use pesticides that contain active synthetic materials. Many negative effects arise from the folly use of chemical pesticides. Among the negative effect is the increase of pest population, resistance, death of natural enemy population and increase in residue level on Agricultural product which makes it unsafe for public consumption [8]. Therefore, it is necessary to find an alternative method in the control of crop pest. The best alternative that can be done is to replace the chemical insecticide with biological control which involves the use of living things in the form of microorganisms. In these profiling microbial communities, the main objective is to identify which bacteria and how much they are present in the environments. Most microbial profiling methods focus on the identification and quantification of bacteria with already sequenced genomes. Further, most methods utilize information obtained from entire genomes. Homology-based methods such as [1–4] classify sequences by detecting homology in reads belonging to either an entire genome or only a small set of marker genes. Composition-based methods generally use conserved compositional features of genomes for classification and as such they utilize less computational resources.Using the 16S rRNA gene instead of whole genome information is not only computational efficient but also economical; Illumina indicated that targeted sequencing of a focused region of interest reduces sequencing costs and enables deep sequencing, compared to whole-genome sequencing. On the other hand, as observed by [8], by focusing exclusively on one gene, one might lose essential information for advanced analyses. We, however, will provide an analysis that demonstrates that at least in the context of oral microbial communities, the 16S rRNA gene retains sufficient information to allow us detect unknown bacteria [9, 10]. This study aimed at employing 16S rRNA as an instrument of identification of seemingly close Bacillus species. Abbreviations BLAST, Basic Local Alignment sequence Tools; PCR, Polymerase Chains reactions; rRNA, ribosomal RNA; Material and methods T Sample collection. Soil samples were collected from three sources from Rice, Sugar Cane, vegetables and abandoned farmland in January 2019. The samples were labeled serially from Sample 1 to Sample 10 (S1 to S10). Bacterial culture: A serial dilution of 10 folds was performed. Bacterial suspension was diluted (10-10) with saline water and 100 μl of bacterial suspension werespread on Nutrient Agar plate and incubated for 24 hours. Bacterial colonies were isolated and grown in Nutrient Broth and nutrient agar. Other microbiological solid agar used include: Chocolate, Blood Agar, EMB, MacConkey, Simon citrate, MRS Agar. Bacteria were characterized by conventional technique by the use of morphological appearance and performance on biochemical analysis [11]. Identification of bacteria:The identification of bacteria was based on morphological characteristics and biochemical tests carried out on the isolates. Morphological characteristics observed for each bacteria colony after 24 h of growth included colony appearance; cell shape, color, optical characteristics, consistency, colonial appearance and pigmentation. Biochemical characterizations were performed according to the method of [12] Catalase test: A small quantity of 24 h old culture was transferred into a drop of 3% Hydrogen peroxide solution on a clean slide with the aid of sterile inoculating loop. Gas seen as white froth indicates the presence of catalase enzyme [13] on the isolates. DNA Extraction Processes The extraction processes was in four phase which are: Collection of cell, lyses of cell, Collection of DNA by phenol, Concentration and purification of DNA. Collection of cell: the pure colonyof the bacteria culture was inoculated into a prepared sterile nutrient broth. After growth is confirmed by the turbidity of the culture, 1.5ml of the culture was taken into a centrifuge tube and was centrifuge at 5000 rpm for 5 minutes; the supernatant layer was discarded leaving the sediment. Lyses of cell: 400 microns of lyses buffer is added to the sediment and was mixed thoroughly and allow to stand for five minutes at room temperature (25°c). 200 microns of Sodium Dodecyl Sulfate (SDS) solution was added for protein lyses and was mixed gently and incubated at 65°c for 10 minutes. Collection of DNA by phenol; 500 microns of phenol chloroform was added to the solution for the separation of DNA, it was mixed completely and centrifuge at 10,000 rpm for 10 minutes. The white pallet seen at the top of the tube after centrifugation is separated into another sterile tube and 1micron of Isopropanol is added and incubated for 1hour at -20°c for precipitation of DNA. The DNA is seen as a colorless liquid in the solution. Concentration and purification of DNA: the solution was centrifuge at 10,000 rpm for 10 minutes. The supernatant layer was discarded and the remaining DNA pellets was washed with 1micron of 17% ethanol, mixed and centrifuge at 10,000 rpm for 10 minutes. The supernatant layer was discarded and air dried. 60 micron TE. Buffer was added for further dissolving of the DNA which was later stored at -40°c until it was required for use [14]. PCR Amplification This requires the use of primers (Forward and Reverse), polymerase enzyme, a template DNA and the d pieces which includedddATP, ddGTP and ddTTP, ddNTP. All this are called the master mix. The PCR reactions consist of three main cycles. The DNA sample was heated at 940c to separate the two template of the DNA strand which was bonded by a hydrogen bond. Once both strand are separated the temperature is reduced to 570c (Annealing temperature). This temperature allows the binding of the forward and reverse primers to the template DNA. After binding the temperature is raised back to 720c which leads to the activation of polymerase enzyme and its start adding d NTPs to the DNA leading to the synthesize of new strands. The cycles were repeated several times in order to obtain millions of the copies of the target DNA [15]. Preparation of Agarose Gel One gram (1 g) of agarose for DNA was measured or 2 g of agarose powdered will be measured for PCR analysis. This done by mixing the agarose powder with 100 ml 1×TAE in a microwaveable flask and microwaved for 1-3 minutes until the agarose is completely dissolved (do not over boil the solution as some of the buffer will evaporate) and thus alter the final percentage of the agarose in the gel. Allow the agarose solution to cool down to about 50°c then after five minutes 10µL was added to EZ vision DNA stain. EZ vision binds to the DNA and allows one to easily visualize the DNA under ultra violet (UV) light. The agarose was poured into the gel tray with the well comb firmly in place and this was placed in newly poured gel at 4°c for 10-15 mins or it sit at room temperature for 20-30 mins, until it has completely solidified[16]. Loading and Running of samples on Agarose gel The agarose gel was placed into the chamber, and the process of electrophoresis commenced with running buffer introduced into the reservoir at the end of the chamber until it the buffer covered at least 2millimeter of the gel. It is advisable to place samples to be loaded in the correct order according to the lanes they are assigned to be running. When loading the samples keep the pipette tip perpendicular to the row of the wells as by supporting your accustomed hand with the second hand; this will reduce the risk of accidentally puncturing the wells with the tip. Lower the tip of the pipette until it breaks the surface of the buffer and is located just above the well. Once all the samples have been loaded it is advised to always avoid any movement of the gel chamber. This might result in the sample spilling into adjacent well. Place the lid on the gel chamber with the terminal correctly positioned to the matching electrodes on the gel chamber black to black and red to red. Remember that DNA is negatively charged hence the movement of the electric current from negatively charged to the positively charged depending on the bandwidth in Kilobytes. Once the electrode is connected to the power supply, switch ON the power supply then set the correct constant voltage (100) and stopwatch for proper time. Press the start button to begin the flow of current that will separate the DNA fragment.After few minutes the samples begins to migrate from the wells into the gel. As the DNA runs, the diaphragm moves from the negative electrode towards the positive electrode [17]. PCR mix Components and Sanger Sequencing This is made up of primers which is both Forward and Reverse, the polymerase enzyme (Taq), a template DNA and the pieces of nucleotides which include: ddNTP, ddATP, ddGTP and ddTTP. Note that the specific Primer’s sequences for bacterial identification is: 785F 5' (GGA TTA GAT ACC CTG GTA) 3', 27F 5' (AGA GTT TGA TCM TGG CTC AG) 3', 907R 5' (CCG TCA ATT CMT TTR AGT TT) 3', 1492R 5' (TAC GGY TAC CTT GTT ACG ACT T) 3' in Sanger Sequencing techniques. BLAST The resulting genomic sequence were assembled and submitted in GenBank at NCBI for assignment of accession numbers. The resultant assertion numbers were subjected to homology search by using Basic Local Alignment Search Tool (BLAST) as NCBI with the assertion number MW362290, MW362291, MW362292, MW362293, MW362294 and MW362295 respectively. Whereas, the other isolates’ accession numbers were retrieved from NCBI GenBank which are:AB 738796.1, JH792136.1, MW 015768.1 and MG745385.1.MEGA 5.2 software was used for the construction of phylogenetic tree and phylogenetic analysis. All the organisms possess 100% identities, 0% gaps and 0.0% E.value which indicated that the organisms are closely related to the existing organisms. The use of 16S rRNA is the best identification process for bacteria because 16S rRNA gene has a distinguishing size of about 500 bases until 1500bp. Rather than using 23S rRNA which is of higher variation, The 16S rRNA is adopted in prokaryotes. 18S rRNA is used for identification in Eukaryotes Results The results of both the conventional morphological and cultural identification was correlated with the molecular sequencing results. Six isolates were confirmed B. cereus species while the other four isolates were. B. wiedmannii, B. thuringiensis, B. toyonensis and B. pseudomycoides.The 16S rRNA sequence of six isolates MW 362290.1- MW362295.1 were assigned accession numbers and deposited in the GenBank while the other four sequences were aligned to those available in the NCBI database. The alignment results showed closely relatedness to LT844650.1with an identity of 100% to 92.2% as above. The six isolates of Bacillus cereus great evolutionary relatedness as shown in the phylogenetic tree constructed using MEGA X software. Results The results of both the conventional morphological and cultural identification was correlated with the molecular sequencing results. Six isolates were confirmed B. cereus species while the other four isolates were. B. wiedmannii, B. thuringiensis, B. toyonensis and B. pseudomycoides.The 16S rRNA sequence of six isolates MW 362290.1- MW362295.1 were assigned accession numbers and deposited in the GenBank while the other four sequences were aligned to those available in the NCBI database. The alignment results showed closely relatedness to LT844650.1with an identity of 100% to 92.2% as above. The six isolates of Bacillus cereus great evolutionary relatedness as shown in the phylogenetic treeconstructed using MEGA X software. Discussion The results obtained in this study is consistent with the previous studies in other countries22,23 The results of the phylogenetic analysis of the 16S rRNA isolate of in this study was similar to the housekeeping genes proposed by [18, 19]. In comparing this study with the earlier study, B. cereus group comprising other species of Bacillus was hypothesized to be considered to form a single species with different ecotypes and pathotype. This study was able to phenotypically differentiated B. thuringiensis, B. pseudomycoides, B. toyonensis, B. wiedmannii and B. cereus sensu strito. Despite differences at the colonial appearance level, the 16S rRNA sequences have homology ranging from 100% to 92% providing insufficient resolution at the species level [6, 7, 18].After analysis through various methods, the strain was identified as Gram-positive bacteria of Bacillus cereus with a homology of 99.4%. Cohan [20] demonstrated that 95–99% of the similarity of 16S rRNA gene sequence between two bacteria hints towards a similar species while >99% indicates the same bacteria.The phylogenetic tree showed that B. toyonensis, B. thuringiensis and B. wiedmanniiare the outgroups of B. cereus group while B. pseudomycoides are most closely related to B. cereus group [19, 21, 22]. Conclusion In the area of molecular epidemiology, genotypic typing method has greatly increased our ability to differentiate between micro-organisms at the intra and interspecies levels and have become an essential and powerful tool. Phenotypic method will still remain important in diagnostic microbiology and genotypic method will become increasingly popular. After analysis through various methods, the strain was identified as Gram-positive bacteria of Bacillus cereus with a homology of between 100% and 92.3%. Acknowledgments Collate acknowledgments in a separate section at the end of the article before the references, not as a footnote to the title. Use the unnumbered Acknowledgements Head style for the Acknowledgments heading. List here those individuals who provided help during the research. Conflicts of interest The Authors declare that there is no conflict of interest. References: Simpkins Meyer F.; Paarmann D.; D’Souza M.; Olson R.; Glass EM.; Kubal M.; Paczian T.; Rodriguez A.; Stevens R. Wilke A The metagenomics rast server–a public resource for the automatic phylogenetic and functional analysis of metagenomes. BMC Bioinformatics. 2008, 9(1), 386. Segata N.; Waldron L.; Ballarini A.; Narasimhan V.; Jousson O.; Huttenhower C. Metagenomic microbial community profiling using unique clade-specific marker genes. Nature methods. 2012, 9(8), 811–814. Brady A.; Salzberg SL. Phymm and phymmbl: metagenomic phylogenetic classification with interpolated markov models. 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DNA Extraction from a bacterial cell. A video on Experimental Biotechnology. 2020. Quick biochemistry. A YouTube video on polymerase chain reaction. 2018. Bio-Rad laboratories. A YouTube video on loading and running of samples on Agarose gel. 2012. Saitou N. and Nei, M. The neighbor-joining method: a new method for reconstructing phylogenetic trees. Biol. Evol. 1987, 4, 406-425. Doi: 101093/oxfordjournals. Lazarte N.J.; Lopez R.P.; Ghiringhelli P.D.; Beron C.M. Bacillus wiedmannii biovar thuringiensis: A specialized Mosquitocidal pathogen with plasmid from diverse origins Genome. Evol. 2018, 10(10), 2823-2833. Doi.1093/gbe/evy211 Cohan, F.M. What are bacterial species? Rev. Microbiol. 2002, 56, 457-487 Abiola C.; Oyetayo V.O. Isolation and Biochemical Characterization of Microorganisms Associated with the Fermentation of Kersting’s Groundnut (Macrotyloma geocarpum). Research Journal of Microbiology, 2016, 11: 47- 55.DOI:10.3923/jm.2016.47.55 Adeoti O.M.; Usman T.A. Molecular Characterization of Rhizobacteria Isolates from Saki, Nigeria. Eur. Of Bio. Biotech. 2021, 2(2), 159. Doi 10.24018/ejbio.2021

Lentil (Lens culinaris Medik.) is a traditional crop in Sicily, Italy. Near Villalba (Caltanissetta), a local lentil landrace, “Lenticchia di Villalba”, is commonly grown. From 2002 to 2004, wilt was observed in five lentil fields (≈1 ha each) at rates from 5 to 20%. Affected plants were yellow and stunted with discoloration in the vascular tissue of stems and crowns. Pieces of brown vascular tissue from stems were disinfested in 2% sodium hypochlorite for 2 min, rinsed with sterile distilled water, placed on potato dextrose agar, and incubated at 23°C. Isolates with morphological characteristics of Fusarium oxysporum Schlecht.:Fr. (2) were consistently recovered from affected plants. For molecular identification of five isolates, the rDNA internal transcribed spacer (ITS) region and a portion of the elongation factor EF-1α were sequenced using ITS5/4 and EF1/2 primers, respectively (1). Two sequences of the ITS region were obtained: a 468-bp sequence from isolates ER1259, ER1260, and ER1275 (submitted as GenBank Accession No. EU159118) and a 483-bp sequence from isolates ER1274 and ER1276 (submitted as GenBank Accession No. EU281661). The two sequences shared 93% similarity. A sequence homology search using the NCBI BLAST program revealed that the first sequence had 100% homology with the ITS sequences of more than 50 F. oxysporum isolates of various formae speciales in GenBank and the second shared 100% homology with the ITS sequences of five isolates of F. redolens Wollenw. (e.g., GenBank Accession No. X94169 of the strain CBS 360.87). Amplification of the EF-1α produced a sequence from isolates ER1274 and ER1276 (submitted as GenBank Accession No. EU281660) with 99 to 100% homology to sequences of F. redolens and a sequence from strains ER1259, ER1275, and ER1260 (submitted as GenBank Accession No. EU281659) with 100% homology to that of more than 50 F. oxysporum strains in GenBank. Although F. redolens and F. oxysporum are morphologically similar, recent molecular studies have shown that they are distinct and phylogenetically distant species (3). On the basis of genetic sequences, isolates ER1274 and ER1276 were identified as F. redolens. These isolates were evaluated for pathogenicity on lentil. For each isolate, 10 2-week-old seedlings of “Lenticchia di Villalba” were inoculated by submerging roots in a suspension of 2.5 × 106 conidia/ml for 10 min. Plants were put into separate tubes containing 70 ml of a nutritional liquid medium (7 ml of HydroPlus Olikani per liter; Yara, Nanterre, France) and incubated in a growth chamber at 20°C with 12 h of light per day. Seedlings dipped in sterile water served as the control treatment. The pathogenicity test was repeated twice. Inoculated seedlings started to wilt 1 week after inoculation and developed root rot and vascular discoloration. After 2 weeks, 70% of the inoculated plants were affected by both isolates and 40 and 10% died when inoculated with ER1274 and ER1276 isolates, respectively. F. redolens was consistently reisolated from the stems of wilted plants. Noninoculated plants remained healthy. Currently, only F. oxysporum f. sp. lentis Vasud. and Sriniv. has been reported as the cause of Fusarium wilt of lentil. To our knowledge, this is the first report of F. redolens as a pathogen on lentil. References: (1) R. P. Baayen et al. Phytopathology 91:1037, 2001. (2) P. E. Nelson et al. Fusarium Species: An Illustrated Manual for Identification. The Pennsylvania State University Press, University Park, 1983. (3) K. O'Donnell et al. Mycologia 90:465, 1998.

During a survey of potato scab pathogens in China from 2003 to 2012, a new pathogen was found in Shanxi and Neimenggu provinces. The incidence was approximately 20% of all recovered strains. The lesions caused by the pathogen were slightly raised and similar to those caused by Streptomyces scabies (3). Lesions were excised (approximately 10 mm3) from 40 infected tubers, surface-disinfested with 0.3% NaOCl for 30 s, rinsed in sterile water three times, cut into 5 mm3, then sliced into 1-mm pieces, and plated on water agar amended with ampicillin (50 μg/ml). Plates were incubated at 28°C in the dark for 4 days. The spores of Streptomyces sp. strains growing from the tuber pieces were collected from single bacterial colonies and cultured on oatmeal agar. To fulfill Koch's postulates, one strain, CPS-2, was grown at 28°C for 10 days and the spores were washed from the plates as inoculum. One hundred milliliters of inoculum (1 × 105 CFU/ml) was mixed with autoclaved soil and vermiculite (1:1) in each pot (15 cm in diameter). Cut tubers were planted in the pots (potato cv. Favorita, one plant per pot, five replicates) and grown under greenhouse conditions (22 ± 5°C). Typical common scab symptoms consisting of small, brown, raised lesions developed on potato tubers 12 weeks after planting. The same strain was re-isolated from the lesions of the new scabby tubers. Non-inoculated plants, treated as described above, but without strain CPS-2, remained healthy. The CPS-2 strain was identified based on morphological and physiological characterization and 16S rDNA sequence. On yeast-malt extract agar, the test strain produced grayish-white aerial hypha, reddish brown substrate mycelium and pigments, and loose spiral spore chains. Spores were smooth and were 0.8 to 0.9 × 1.1 to 1.2 μm in size (diameter and length). The ability of the strain to use single sources of carbon and nitrogen was verified according to the International Streptomyces project (4). The strain grew in media supplemented with L-arabinose, D-fructose, D-glucose, rhamnose, raffinose, meso-inositol, sucrose, and D-xylose, but not D-mannitol. It used L-hydroxyproline, L-methionine, and L-histidine, and produced melanin on tyrosine and peptone yeast extract agar. The strain did not grow at a pH less than 5.0 and was sensitive to streptomycin (20 μg/ml), phenol (0.1%), and crystal violet (0.5 μg/mL), but not to penicillin (10 IU/ml). The strain also produced hydrogen sulfide. The biological characteristics of strain CPS-2 were in accord with Streptomyces galilaeus. CPS-2 produced thaxtomin A in oatmeal liquid medium and the txt AB gene fragment was successfully amplified using specific primers (2). The 16S rDNA sequence of CPS-2 was amplified by PCR with primers 16S1-F: 5′-CATTCACGGAGAGTTTGATCC-3′ and 16S1-R: 5′-AGAAAGGAGGTGATCCAGCC-3′ (1) and sequenced. A BLAST search of the 16S rDNA sequence for CPS-2 was conducted using the NCBI GenBank database, resulting in 99.8% similarity to S. galilaeus (NR_040857). The 16S rDNA sequence for CPS-2 (1,388 bp) was deposited in GenBank (AY621378). To our knowledge, this is the first report of S. galilaeus causing common scab of potato in China. References: (1) R. A. Bukhalid et al. Appl. Environ. Microbiol. 68:738, 2002. (2) R. Flores-González et al. Plant Pathol. 57:162, 2008. (3) D. H. Lambert and R. Loria. Int. J. Syst. Bacteriol. 39:387, 1989. (4) E. B. Shirling and D. Gottlieb. Int. J. Syst. Bacteriol. 16:313, 1966.

Environments containing significant concentration of NaCl such as salt lakes harbor extremophiles microorganisms which have a great biotechnology interest. To explore the diversity of Bacteria in Chott Tinsilt (Algeria), an isolation program was performed. Water samples were collected from the saltern during the pre-salt harvesting phase. This Chott is high in salt (22.47% (w/v). Seven halophiles Bacteria were selected for further characterization. The isolated strains were able to grow optimally in media with 10–25% (w/v) total salts. Molecular identification of the isolates was performed by sequencing the 16S rRNA gene. It showed that these cultured isolates included members belonging to the Halomonas, Staphylococcus, Salinivibrio, Planococcus and Halobacillus genera with less than 98% of similarity with their closest phylogenetic relative. The halophilic bacterial isolates were also characterized for the production of biosurfactant and industrially important enzymes. Most isolates produced hydrolases and biosurfactants at high salt concentration. In fact, this is the first report on bacterial strains (A4 and B4) which were a good biosurfactant and coagulase producer at 20% and 25% ((w/v)) NaCl. In addition, the biosurfactant produced by the strain B4 at high salinity (25%) was also stable at high temperature (30-100°C) and high alkalinity (pH 11).Key word: Salt Lake, Bacteria, biosurfactant, Chott, halophiles, hydrolases, 16S rRNAINTRODUCTIONSaline lakes cover approximately 10% of the Earth’s surface area. The microbial populations of many hypersaline environments have already been studied in different geographical regions such as Great Salt Lake (USA), Dead Sea (Israel), Wadi Natrun Lake (Egypt), Lake Magadi (Kenya), Soda Lake (Antarctica) and Big Soda Lake and Mono Lake (California). Hypersaline regions differ from each other in terms of geographical location, salt concentration and chemical composition, which determine the nature of inhabitant microorganisms (Gupta et al., 2015). Then low taxonomic diversity is common to all these saline environments (Oren et al., 1993). Halophiles are found in nearly all major microbial clades, including prokaryotic (Bacteria and Archaea) and eukaryotic forms (DasSarma and Arora, 2001). They are classified as slight halophiles when they grow optimally at 0.2–0.85 M (2–5%) NaCl, as moderate halophiles when they grow at 0.85–3.4 M (5–20%) NaCl, and as extreme halophiles when they grow at 3.4–5.1 M (20–30%) NaCl. Hyper saline environments are inhabited by extremely halophilic and halotolerant microorganisms such as Halobacillus sp, Halobacterium sp., Haloarcula sp., Salinibacter ruber , Haloferax sp and Bacillus spp. (Solomon and Viswalingam, 2013). There is a tremendous demand for halophilic bacteria due to their biotechnological importance as sources of halophilic enzymes. Enzymes derived from halophiles are endowed with unique structural features and catalytic power to sustain the metabolic and physiological processes under high salt conditions. Some of these enzymes have been reported to be active and stable under more than one extreme condition (Karan and Khare, 2010). Applications are being considered in a range of industries such as food processing, washing, biosynthetic processes and environmental bioremediation. Halophilic proteases are widely used in the detergent and food industries (DasSarma and Arora, 2001). However, esterases and lipases have also been useful in laundry detergents for the removal of oil stains and are widely used as biocatalysts because of their ability to produce pure compounds. Likewise, amylases are used industrially in the first step of the production of high fructose corn syrup (hydrolysis of corn starch). They are also used in the textile industry in the de-sizing process and added to laundry detergents. Furthermore, for the environmental applications, the use of halophiles for bioremediation and biodegradation of various materials from industrial effluents to soil contaminants and accidental spills are being widely explored. In addition to enzymes, halophilic / halotolerants microorganisms living in saline environments, offer another potential applications in various fields of biotechnology like the production of biosurfactant. Biosurfactants are amphiphilic compounds synthesized from plants and microorganisms. They reduce surface tension and interfacial tension between individual molecules at the surface and interface respectively (Akbari et al., 2018). Comparing to the chemical surfactant, biosurfactant are promising alternative molecules due to their low toxicity, high biodegradability, environmental capability, mild production conditions, lower critical micelle concentration, higher selectivity, availability of resources and ability to function in wide ranges of pH, temperature and salinity (Rocha et al., 1992). They are used in various industries which include pharmaceuticals, petroleum, food, detergents, cosmetics, paints, paper products and water treatment (Akbari et al., 2018). The search for biosurfactants in extremophiles is particularly promising since these biomolecules can adapt and be stable in the harsh environments in which they are to be applied in biotechnology.OBJECTIVESEastern Algeria features numerous ecosystems including hypersaline environments, which are an important source of salt for food. The microbial diversity in Chott Tinsilt, a shallow Salt Lake with more than 200g/L salt concentration and a superficies of 2.154 Ha, has never yet been studied. The purpose of this research was to chemically analyse water samples collected from the Chott, isolate novel extremely or moderate halophilic Bacteria, and examine their phenotypic and phylogenetic characteristics with a view to screening for biosurfactants and enzymes of industrial interest.MATERIALS AND METHODSStudy area: The area is at 5 km of the Commune of Souk-Naâmane and 17 km in the South of the town of Aïn-Melila. This area skirts the trunk road 3 serving Constantine and Batna and the railway Constantine-Biskra. It is part the administrative jurisdiction of the Wilaya of Oum El Bouaghi. The Chott belongs to the wetlands of the High Plains of Constantine with a depth varying rather regularly without never exceeding 0.5 meter. Its length extends on 4 km with a width of 2.5 km (figure 1).Water samples and physico-chemical analysis: In February 2013, water samples were collected from various places at the Chott Tinsilt using Global Positioning System (GPS) coordinates of 35°53’14” N lat. and 06°28’44”E long. Samples were collected randomly in sterile polythene bags and transported immediately to the laboratory for isolation of halophilic microorganisms. All samples were treated within 24 h after collection. Temperature, pH and salinity were measured in situ using a multi-parameter probe (Hanna Instruments, Smithfield, RI, USA). The analytical methods used in this study to measure ions concentration (Ca2+, Mg2+, Fe2+, Na+, K+, Cl−, HCO3−, SO42−) were based on 4500-S-2 F standard methods described elsewhere (Association et al., 1920).Isolation of halophilic bacteria from water sample: The media (M1) used in the present study contain (g/L): 2.0 g of KCl, 100.0/200.0 g of NaCl, 1.0 g of MgSO4.7HO2, 3.0 g of Sodium Citrate, 0.36 g of MnCl2, 10.0 g of yeast extract and 15.0 g agar. The pH was adjusted to 8.0. Different dilutions of water samples were added to the above medium and incubated at 30°C during 2–7 days or more depending on growth. Appearance and growth of halophilic bacteria were monitored regularly. The growth was diluted 10 times and plated on complete medium agar (g/L): glucose 10.0; peptone 5.0; yeast extract 5.0; KH2PO4 5.0; agar 30.0; and NaCl 100.0/200.0. Resultant colonies were purified by repeated streaking on complete media agar. The pure cultures were preserved in 20% glycerol vials and stored at −80°C for long-term preservation.Biochemical characterisation of halophilic bacterial isolates: Bacterial isolates were studied for Gram’s reaction, cell morphology and pigmentation. Enzymatic assays (catalase, oxidase, nitrate reductase and urease), and assays for fermentation of lactose and mannitol were done as described by Smibert (1994).Optimization of growth conditions: Temperature, pH, and salt concentration were optimized for the growth of halophilic bacterial isolates. These growth parameters were studied quantitatively by growing the bacterial isolates in M1 medium with shaking at 200 rpm and measuring the cell density at 600 nm after 8 days of incubation. To study the effect of NaCl on the growth, bacterial isolates were inoculated on M1 medium supplemented with different concentration of NaCl: 1%-35% (w/v). The effect of pH on the growth of halophilic bacterial strains was studied by inoculating isolates on above described growth media containing NaCl and adjusted to acidic pH of 5 and 6 by using 1N HCl and alkaline pH of 8, 9, 10, 11 and 12 using 5N NaOH. The effect of temperature was studied by culturing the bacterial isolates in M1 medium at different temperatures of incubation (4°C–55°C).Screening of halophilic bacteria for hydrolytic enzymes: Hydrolase producing bacteria among the isolates were screened by plate assay on starch, tributyrin, gelatin and DNA agar plates respectively for amylase, lipase, protease and DNAse activities. Amylolytic activity of the cultures was screened on starch nutrient agar plates containing g/L: starch 10.0; peptone 5.0; yeast extract 3.0; agar 30.0; NaCl 100.0/250.0. The pH was 7.0. After incubation at 30 ºC for 7 days, the zone of clearance was determined by flooding the plates with iodine solution. The potential amylase producers were selected based on ratio of zone of clearance diameter to colony diameter. Lipase activity of the cultures was screened on tributyrin nutrient agar plates containing 1% (v/v) of tributyrin. Isolates that showed clear zones of tributyrin hydrolysis were identified as lipase producing bacteria. Proteolytic activity of the isolates was similarly screened on gelatin nutrient agar plates containing 10.0 g/L of gelatin. The isolates showing zones of gelatin clearance upon treatment with acidic mercuric chloride were selected and designated as protease producing bacteria. The presence of DNAse activity on plates was determined on DNAse test agar (BBL) containing 10%-25% (w/v) total salt. After incubation for 7days, the plates were flooded with 1N HCl solution. Clear halos around the colonies indicated DNAse activity (Jeffries et al., 1957).Milk clotting activity (coagulase activity) of the isolates was also determined following the procedure described (Berridge, 1952). Skim milk powder was reconstituted in 10 mM aqueous CaCl2 (pH 6.5) to a final concentration of 0.12 kg/L. Enzyme extracts were added at a rate of 0.1 mL per mL of milk. The coagulation point was determined by manual rotating of the test tube periodically, at short time intervals, and checking for visible clot formation.Screening of halophilic bacteria for biosurfactant production. Oil spread Assay: The Petridis base was filled with 50 mL of distilled water. On the water surface, 20μL of diesel and 10μl of culture were added respectively. The culture was introduced at different spots on the diesel, which is coated on the water surface. The occurrence of a clear zone was an indicator of positive result (Morikawa et al., 2000). The diameter of the oil expelling circles was measured by slide caliber (with a degree of accuracy of 0.02 mm).Surface tension and emulsification index (E24): Isolates were cultivated at 30 °C for 7 days on the enrichment medium containing 10-25% NaCl and diesel oil as the sole carbon source. The medium was centrifuged (7000 rpm for 20 min) and the surface tension of the cell-free culture broth was measured with a TS90000 surface tensiometer (Nima, Coventry, England) as a qualitative indicator of biosurfactant production. The culture broth was collected with a Pasteur pipette to remove the non-emulsified hydrocarbons. The emulsifying capacity was evaluated by an emulsification index (E24). The E24 of culture samples was determined by adding 2 mL of diesel oil to the same amount of culture, mixed for 2 min with a vortex, and allowed to stand for 24 h. E24 index is defined as the percentage of height of emulsified layer (mm) divided by the total height of the liquid column (mm).Biosurfactant stability studies : After growth on diesel oil as sole source of carbone, cultures supernatant obtained after centrifugation at 6,000 rpm for 15 min were considered as the source of crude biosurfactant. Its stability was determined by subjecting the culture supernatant to various temperature ranges (30, 40, 50, 60, 70, 80 and 100 °C) for 30 min then cooled to room temperature. Similarly, the effect of different pH (2–11) on the activity of the biosurfactant was tested. The activity of the biosurfactant was investigated by measuring the emulsification index (El-Sersy, 2012).Molecular identification of potential strains. DNA extraction and PCR amplification of 16S rDNA: Total cellular DNA was extracted from strains and purified as described by Sambrook et al. (1989). DNA was purified using Geneclean® Turbo (Q-BIO gene, Carlsbad, CA, USA) before use as a template in polymerase chain reaction (PCR) amplification. For the 16S rDNA gene sequence, the purified DNA was amplified using a universal primer set, forward primer (27f; 5′-AGA GTT TGA TCM TGG CTC AG) and a reverse primer (1492r; 5′-TAC GGY TAC CTT GTT ACG ACT T) (Lane, 1991). Agarose gel electrophoresis confirmed the amplification product as a 1400-bp DNA fragment.16S rDNA sequencing and Phylogenic analysis: Amplicons generated using primer pair 27f-1492r was sequenced using an automatic sequencer system at Macrogene Company (Seoul, Korea). The sequences were compared with those of the NCBI BLAST GenBank nucleotide sequence databases. Phylogenetic trees were constructed by the neighbor-joining method using MEGA version 5.05 software (Tamura et al., 2011). Bootstrap resembling analysis for 1,000 replicates was performed to estimate the confidence of tree topologies.Nucleotide sequence accession numbers: The nucleotide sequences reported in this work have been deposited in the EMBL Nucleotide Sequence Database. The accession numbers are represented in table 5.Statistics: All experiments were conducted in triplicates. Results were evaluated for statistical significance using ANOVA.RESULTSPhysico-chemical parameters of the collected water samples: The physicochemical properties of the collected water samples are reported in table 1. At the time of sampling, the temperature was 10.6°C and pH 7.89. The salinity of the sample, as determined in situ, was 224.70 g/L (22,47% (w/v)). Chemical analysis of water sample indicated that Na +and Cl- were the most abundant ions (table 1). SO4-2 and Mg+2 was present in much smaller amounts compared to Na +and Cl- concentration. Low levels of calcium, potassium and bicarbonate were also detected, often at less than 1 g/L.Characterization of isolates. Morphological and biochemical characteristic feature of halophilic bacterial isolates: Among 52 strains isolated from water of Chott Tinsilt, seven distinct bacteria (A1, A2, A3, A4, B1, B4 and B5) were chosen for further characterization (table 2). The colour of the isolates varied from beige, pale yellow, yellowish and orange. The bacterial isolates A1, A2, A4, B1 and B5 were rod shaped and gram negative (except B5), whereas A3 and B4 were cocci and gram positive. All strains were oxidase and catalase positive except for B1. Nitrate reductase and urease activities were observed in all the bacterial isolates, except B4. All the bacterial isolates were negative for H2S formation. B5 was the only strain positive for mannitol fermentation (table 2).We isolated halophilic bacteria on growth medium with NaCl supplementation at pH 7 and temperature of 30°C. We studied the effect of NaCl, temperature and pH on the growth of bacterial isolates. All the isolates exhibited growth only in the presence of NaCl indicating that these strains are halophilic. The optimum growth of isolates A3 and B1 was observed in the presence of 10% NaCl, whereas it was 15% NaCl for A1, A2 and B5. A4 and B4 showed optimum growth in the presence of 20% and 25% NaCl respectively. A4, B4 and B5 strains can tolerate up to 35% NaCl.The isolate B1 showed growth in medium supplemented with 10% NaCl and pH range of 7–10. The optimum pH for the growth B1 was 9 and they did not show any detectable growth at or below pH 6 (table 2), which indicates the alkaliphilic nature of B1 isolate. The bacterial isolates A1, A2 and A4 exhibited growth in the range of pH 6–10, while A3 and B4 did not show any growth at pH greater than 8. The optimum pH for growth of all strains (except B1) was pH 7.0 (table 2). These results indicate that A1, A2, A3, A4, B4 and B5 are neutrophilic in nature. All the bacterial isolates exhibited optimal growth at 30°C and no detectable growth at 55°C. Also, detectable growth of isolates A1, A2 and A4 was observed at 4°C. However, none of the bacterial strains could grow below 4°C and above 50°C (table 2).Screening of the halophilic enzymes: To characterize the diversity of halophiles able to produce hydrolytic enzymes among the population of microorganisms inhabiting the hypersaline habitats of East Algeria (Chott Tinsilt), a screening was performed. As described in Materials and Methods, samples were plated on solid media containing 10%-25% (w/v) of total salts and different substrates for the detection of amylase, protease, lipase and DNAse activities. However, coagulase activity was determined in liquid medium using milk as substrate (figure 3). Distributions of hydrolytic activity among the isolates are summarized in table 4.From the seven bacterial isolates, four strains A1, A2, A4 and B5 showed combined hydrolytic activities. They were positive for gelatinase, lipase and coagulase. A3 strain showed gelatinase and lipase activities. DNAse activities were detected with A1, A4, B1 and B5 isolates. B4 presented lipase and coagulase activity. Surprisingly, no amylase activity was detected among all the isolates.Screening for biosurfactant producing isolates: Oil spread assay: The results showed that all the strains could produce notable (>4 cm diameter) oil expelling circles (ranging from 4.11 cm to 4.67 cm). The average diameter for strain B5 was 4.67 cm, significantly (P < 0.05) higher than for the other strains.Surface tension and emulsification index (E24): The assimilation of hydrocarbons as the sole sources of carbon by the isolate strains led to the production of biosurfactants indicated by the emulsification index and the lowering of the surface tension of cell-free supernatant. Based on rapid growth on media containing diesel oil as sole carbon source, the seven isolates were tested for biosurfactant production and emulsification activity. The obtained values of the surface tension measurements as well as the emulsification index (E24) are shown in table 3. The highest reduction of surface tension was achieved with B5 and A3 isolates with values of 25.3 mN m−1 and 28.1 mN m−1 respectively. The emulsifying capacity evaluated by the E24 emulsification index was highest in the culture of isolate B4 (78%), B5 (77%) and A3 (76%) as shown in table 3 and figure 2. These emulsions were stable even after 4 months. The bacteria with emulsification indices higher than 50 % and/or reduction in the surface tension (under 30 mN/m) have been defined as potential biosurfactant producers. Based on surface tension and the E24 index results, isolates B5, B4, A3 and A4 are the best candidates for biosurfactant production. It is important to note that, strains B4 and A4 produce biosurfactant in medium containing respectively 25% and 20% (w/v) NaCl.Stability of biosurfactant activities: The applicability of biosurfactants in several biotechnological fields depends on their stability at different environmental conditions (temperatures, pH and NaCl). For this study, the strain B4 appear very interesting (It can produce biosurfactant at 25 % NaCl) and was choosen for futher analysis for biosurfactant stability. The effects of temperature and pH on the biosurfactant production by the strain B4 are shown in figure 4.biosurfactant in medium containing respectively 25% and 20% (w/v) NaCl.Stability of biosurfactant activities: The applicability of biosurfactants in several biotechnological fields depends on their stability at different environmental conditions (temperatures, pH and NaCl). For this study, the strain B4 appear very interesting (It can produce biosurfactant at 25 % NaCl) and was chosen for further analysis for biosurfactant stability. The effects of temperature and pH on the biosurfactant production by the strain B4 are shown in figure 4. The biosurfactant produced by this strain was shown to be thermostable giving an E-24 Index value greater than 78% (figure 4A). Heating of the biosurfactant to 100 °C caused no significant effect on the biosurfactant performance. Therefore, the surface activity of the crude biosurfactant supernatant remained relatively stable to pH changes between pH 6 and 11. At pH 11, the value of E24 showed almost 76% activity, whereas below pH 6 the activity was decreased up to 40% (figure 4A). The decreases of the emulsification activity by decreasing the pH value from basic to an acidic region; may be due to partial precipitation of the biosurfactant. This result indicated that biosurfactant produced by strain B4 show higher stability at alkaline than in acidic conditions.Molecular identification and phylogenies of potential isolates: To identify halophilic bacterial isolates, the 16S rDNA gene was amplified using gene-specific primers. A PCR product of ≈ 1.3 kb was detected in all the seven isolates. The 16S rDNA amplicons of each bacterial isolate was sequenced on both strands using 27F and 1492R primers. The complete nucleotide sequence of 1336,1374, 1377,1313, 1305,1308 and 1273 bp sequences were obtained from A1, A2, A3, A4, B1, B4 and B5 isolates respectively, and subjected to BLAST analysis. The 16S rDNA sequence analysis showed that the isolated strains belong to the genera Halomonas, Staphylococcus, Salinivibrio, Planococcus and Halobacillus as shown in table 5. The halophilic isolates A2 and A4 showed 97% similarity with the Halomonas variabilis strain GSP3 (accession no. AY505527) and the Halomonas sp. M59 (accession no. AM229319), respectively. As for A1, it showed 96% similarity with the Halomonas venusta strain GSP24 (accession no. AY553074). B1 and B4 showed for their part 96% similarity with the Salinivibrio costicola subsp. alcaliphilus strain 18AG DSM4743 (accession no. NR_042255) and the Planococcus citreus (accession no. JX122551), respectively. The bacterial isolate B5 showed 98% sequence similarity with the Halobacillus trueperi (accession no. HG931926), As for A3, it showed only 95% similarity with the Staphylococcus arlettae (accession no. KR047785). The 16S rDNA nucleotide sequences of all the seven halophilic bacterial strains have been submitted to the NCBI GenBank database under the accession number presented in table 5. The phylogenetic association of the isolates is shown in figure 5.DICUSSIONThe physicochemical properties of the collected water samples indicated that this water was relatively neutral (pH 7.89) similar to the Dead Sea and the Great Salt Lake (USA) and in contrast to the more basic lakes such as Lake Wadi Natrun (Egypt) (pH 11) and El Golea Salt Lake (Algeria) (pH 9). The salinity of the sample was 224.70 g/L (22,47% (w/v). This range of salinity (20-30%) for Chott Tinsilt is comparable to a number of well characterized hypersaline ecosystems including both natural and man-made habitats, such as the Great Salt Lake (USA) and solar salterns of Puerto Rico. Thus, Chott Tinsilt is a hypersaline environment, i.e. environments with salt concentrations well above that of seawater. Chemical analysis of water sample indicated that Na +and Cl- were the most abundant ions, as in most hypersaline ecosystems (with some exceptions such as the Dead Sea). These chemical water characteristics were consistent with the previously reported data in other hypersaline ecosystems (DasSarma and Arora, 2001; Oren, 2002; Hacěne et al., 2004). Among 52 strains isolated from this Chott, seven distinct bacteria (A1, A2, A3, A4, B1, B4 and B5) were chosen for phenotypique, genotypique and phylogenetique characterization.The 16S rDNA sequence analysis showed that the isolated strains belong to the genera Halomonas, Staphylococcus, Salinivibrio, Planococcus and Halobacillus. Genera obtained in the present study are commonly occurring in various saline habitats across the globe. Staphylococci have the ability to grow in a wide range of salt concentrations (Graham and Wilkinson, 1992; Morikawa et al., 2009; Roohi et al., 2014). For example, in Pakistan, Staphylococcus strains were isolated from various salt samples during the study conducted by Roohi et al. (2014) and these results agreed with previous reports. Halomonas, halophilic and/or halotolerant Gram-negative bacteria are typically found in saline environments (Kim et al., 2013). The presence of Planococcus and Halobacillus has been reported in studies about hypersaline lakes; like La Sal del Rey (USA) (Phillips et al., 2012) and Great Salt Lake (Spring et al., 1996), respectively. The Salinivibrio costicola was a representative model for studies on osmoregulatory and other physiological mechanisms of moderately halophilic bacteria (Oren, 2006).However, it is interesting to note that all strains shared less than 98.7% identity (the usual species cut-off proposed by Yarza et al. (2014) with their closest phylogenetic relative, suggesting that they could be considered as new species. Phenotypic, genetic and phylogenetic analyses have been suggested for the complete identification of these strains. Theses bacterial strains were tested for the production of industrially important enzymes (Amylase, protease, lipase, DNAse and coagulase). These isolates are good candidates as sources of novel enzymes with biotechnological potential as they can be used in different industrial processes at high salt concentration (up to 25% NaCl for B4). Prominent amylase, lipase, protease and DNAase activities have been reported from different hypersaline environments across the globe; e.g., Spain (Sánchez‐Porro et al., 2003), Iran (Rohban et al., 2009), Tunisia (Baati et al., 2010) and India (Gupta et al., 2016). However, to the best of our knowledge, the coagulase activity has never been detected in extreme halophilic bacteria. Isolation and characterization of crude enzymes (especially coagulase) to investigate their properties and stability are in progress.The finding of novel enzymes with optimal activities at various ranges of salt concentrations is of great importance. Besides being intrinsically stable and active at high salt concentrations, halophilic and halotolerant enzymes offer great opportunities in biotechnological applications, such as environmental bioremediation (marine, oilfiel) and food processing. The bacterial isolates were also characterized for production of biosurfactants by oil-spread assay, measurement of surface tension and emulsification index (E24). There are few reports on biosurfactant producers in hypersaline environments and in recent years, there has been a greater increase in interest and importance in halophilic bacteria for biomolecules (Donio et al., 2013; Sarafin et al., 2014). Halophiles, which have a unique lipid composition, may have an important role to play as surface-active agents. The archae bacterial ether-linked phytanyl membrane lipid of the extremely halophilic bacteria has been shown to have surfactant properties (Post and Collins, 1982). Yakimov et al. (1995) reported the production of biosurfactant by a halotolerant Bacillus licheniformis strain BAS 50 which was able to produce a lipopeptide surfactant when cultured at salinities up to 13% NaCl. From solar salt, Halomonas sp. BS4 and Kocuria marina BS-15 were found to be able to produce biosurfactant when cultured at salinities of 8% and 10% NaCl respectively (Donio et al., 2013; Sarafin et al., 2014). In the present work, strains B4 and A4 produce biosurfactant in medium containing respectively 25% and 20% NaCl. To our knowledge, this is the first report on biosurfactant production by bacteria under such salt concentration. Biosurfactants have a wide variety of industrial and environmental applications (Akbari et al., 2018) but their applicability depends on their stability at different environmental conditions. The strain B4 which can produce biosurfactant at 25% NaCl showed good stability in alkaline pH and at a temperature range of 30°C-100°C. Due to the enormous utilization of biosurfactant in detergent manufacture the choice of alkaline biosurfactant is researched (Elazzazy et al., 2015). On the other hand, the interesting finding was the thermostability of the produced biosurfactant even after heat treatment (100°C for 30 min) which suggests the use of this biosurfactant in industries where heating is of a paramount importance (Khopade et al., 2012). To date, more attention has been focused on biosurfactant producing bacteria under extreme conditions for industrial and commercial usefulness. In fact, the biosurfactant produce by strain B4 have promising usefulness in pharmaceutical, cosmetics and food industries and for bioremediation in marine environment and Microbial enhanced oil recovery (MEOR) where the salinity, temperature and pH are high.CONCLUSIONThis is the first study on the culturable halophilic bacteria community inhabiting Chott Tinsilt in Eastern Algeria. Different genera of halotolerant bacteria with different phylogeneticaly characteristics have been isolated from this Chott. Culturing of bacteria and their molecular analysis provides an opportunity to have a wide range of cultured microorganisms from extreme habitats like hypersaline environments. Enzymes produced by halophilic bacteria show interesting properties like their ability to remain functional in extreme conditions, such as high temperatures, wide range of pH, and high salt concentrations. These enzymes have great economical potential in industrial, agricultural, chemical, pharmaceutical, and biotechnological applications. Thus, the halophiles isolated from Chott Tinsilt offer an important potential for application in microbial and enzyme biotechnology. In addition, these halo bacterial biosurfactants producers isolated from this Chott will help to develop more valuable eco-friendly products to the pharmacological and food industries and will be usefulness for bioremediation in marine environment and petroleum industry.ACKNOWLEDGMENTSOur thanks to Professor Abdelhamid Zoubir for proofreading the English composition of the present paper.CONFLICT OF INTERESTThe authors declare that they have no conflict of interest.Akbari, S., N. H. Abdurahman, R. M. Yunus, F. Fayaz and O. R. Alara, 2018. Biosurfactants—a new frontier for social and environmental safety: A mini review. Biotechnology research innovation, 2(1): 81-90.Association, A. P. H., A. W. W. Association, W. P. C. 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Roman biotechnol lett, 17(2): 7049-7064.Elazzazy, A. M., T. Abdelmoneim and O. Almaghrabi, 2015. Isolation and characterization of biosurfactant production under extreme environmental conditions by alkali-halo-thermophilic bacteria from Saudi Arabia. Saudi journal of biological Sciences, 22(4): 466-475.Graham, J. E. and B. Wilkinson, 1992. Staphylococcus aureus osmoregulation: Roles for choline, glycine betaine, proline, and taurine. Journal of bacteriology, 174(8): 2711-2716.Gupta, S., P. Sharma, K. Dev and A. Sourirajan, 2016. Halophilic bacteria of lunsu produce an array of industrially important enzymes with salt tolerant activity. Biochemistry research international, 1: 1-10.Gupta, S., P. Sharma, K. Dev, M. Srivastava and A. Sourirajan, 2015. A diverse group of halophilic bacteria exist in lunsu, a natural salt water body of Himachal Pradesh, India. SpringerPlus 4(1): 274.Hacěne, H., F. Rafa, N. Chebhouni, S. Boutaiba, T. Bhatnagar, J. C. Baratti and B. Ollivier, 2004. 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To study the transmission characteristics of near-field detonation noise into water, the detonation noise transmission system is built on a laboratory-scale water tank using a detonation tube with a diameter of 30 mm. The interaction of the detonation gas jet with the air-water interface, the development of the cavity and the growth of the liquid column are experimentally observed by a high-speed camera. The spectral distribution characteristics of detonation noise above and below the interface are recorded by a microphone, a hydrophone and an underwater blast sensor. Analysis of the experimental images shows that the size of the cavity increases with increasing filling pressure and decreases with increasing nozzle height. By normalizing the evolution time of the cavity with the cavity lifetime, it is concluded that the time for the cavity to develop to the deepest is about 0.27, independent of the filling pressure. The pressure field data analysis results show that the main frequencies of the detonation sound waves are 100 Hz and 400 Hz, and the frequency distribution has nothing to do with the filling pressure. Through the defined acoustic wave energy transmission coefficient, it is demonstrated that the detonation acoustic wave transmission coefficient decreases with the increase of the frequency, and the shock wave transmission coefficient decreases with the increase of the angle.

In September 2021, signs of black circular to oval shaped fungal structures (stromata) were observed on corn (Zea mays L.) leaves on a non-commercial inbred line in Todd County, Kentucky. Signs were only observed in a small pocket within the larger field, with disease levels ranging from 1- 5% incidence and 1-25% severity on individual leaves affected in the field. Corn leaves had senesced and only fungal structures were available to aid in diagnosis. Microscopic examination of stromata uncovered ascomata within the clypei/stromata. Further examination of ascomata revealed multiple asci containing eight hyaline, uniseriate, aseptate, oval to ovoid ascospores ranging in size from 8 to 12 µm x 5 to 7 µm. Observed signs were consistent with published reports of tar spot caused by Phyllachora maydis (Parbery 1967; Valle-Torres et al. 2020). For molecular confirmation of the causal agent, corn leaves were surface sterilized in diluted bleach (10%) for 30 seconds and stromata were excised from the leaves using a sterile scalpel. Five to seven stromata were placed into each microcentrifuge tube. Liquid nitrogen was added to the microcentrifuge tubes and the frozen stromata were ground using a sterilized pestle. The ground stromata tissue was used for DNA extraction using a Synergy 2.0 plant DNA extraction kit (OPS Diagnostics, Lebanon, NJ). A portion of the internal transcribed spacer (ITS) region was amplified by PCR utilizing ITS-4 and ITS-5 primers. Amplicons were subjected to Sanger sequencing to obtain a consensus sequence. Using the BLASTn algorithm the consensus sequence shared 100% similarity to three P. maydis Genbank accessions: MG881848.1, MG8814847.1, MG881846.1. A representative sequence was deposited in GenBank (accession no. OQ034699.1). Due to P. maydis being an obligate parasite, Koch’s postulates were not attempted.

Apios americana Medik, commonly known as American groundnut, is a leguminous perennial vine crop native to North America and is cultivated in Japan and Korea (Chu et al. 2019). Its tubers are edible and believed to be very nutritious, especially for women just after childbirth. The tubers also contain secondary metabolites, saponin and genistein, which is good for human health (Ichige et al. 2013). However, the storage of tubers at inappropriate temperatures and humidity levels can cause severe fungal infection, and adversely affect tuber quality. During March and April 2020, a white to pale-orange fungal mycelia were observed on stored American groundnut tubers, with 10 to 15% of seed tubers rotten. Infected tubers were collected, and fungal isolates were isolated on potato dextrose agar (PDA) using the single spore isolation method (Leslie and Summerell 2006). A pure culture (isolate JC20003) was obtained and stored at the Bioenergy Crop Research Institute, NICS, Muan, Republic of Korea. The fungus was cultured on PDA and V8 liquid media for 7 days at 25℃ to observe its morphological characteristics. The length and width of macroconidia ranged from 20.6 to 52.9 μm and 2.9 to 5.1 μm, respectively (n = 30). The microconidia were 8.5 to 14.9 μm and 2.3 to 4.2 μm in length and width, respectively (n = 30). Macroconidia were broadly falcate, strongly septate, 2 to 6 septations with dorsiventral curvature; chlamydospores were formed in chains; and microconidia were fusiform with 0 to 1 septation observed. Genomic DNA of the isolate was extracted using Solgent DNA extraction kit (Solgent, Daejeon, Korea), followed by PCR analysis using the internal transcribed spacer (ITS5/ITS4) and elongation factor (EF-1/EF2) genes (White et al. 1990; O’Donnel 2000). PCR products were sequenced and analyzed to confirm species identity (Yang et al. 2018). These sequences were deposited in GenBank (accession numbers MT703859/ITS and MT731939/EF). BLASTn search analysis showed 100% sequence similarity with Fusarium acuminatum (isolates N-51-1/ITS and WXWH24/EF). Based on morphological and molecular data analysis, the fungus was identified as F. acuminatum (Leslie and Summerell 2006; Marin et al. 2012). Pathogenicity tests were conducted on five tubers inoculated with 5 mm mycelial plugs with three replicates, while a non-mycelial plug served as the control. After 5 days of incubation in plastic containers at 25 °C with high humidity, typical symptoms developed. No symptoms were observed on the control tubers; F. acuminatum was re-isolated from artificially inoculated tubers to complete Koch’s postulates. This is the first report on post-harvest tuber rot caused by F. acuminatum in Apios americana.

Background: Poisoning of animals due to toxic plants is found in Brazil and other countries. One of the known toxic plants in Brazil, with the active ingredient sodium fluoroacetate (SF), is Palicourea marcgravii. Dehalogenases that inactivate the fluor-carbon bonds are enzymes found in microorganisms and may prevent intoxication. This study evaluated the occurrence of rumen microorganisms naturally resistant to SF.Materials, Methods & Results: Two samples of rumen fluid of cattle from the Experimental Farm of Federal University of Mato Grosso fed with Brachiaria sp. were obtained via fistula in flasks. An aliquot of 2 mL was placed in a microtube and centrifuged at 9000 g for 1 min. Then, the sample was inoculated into 2 tubes, one containing 100 µL of clarified rumen fluid in 2 mL of modified liquid culture medium (0.1% ammonium sulfate, 0.1% potassium phosphate monobasic, 0.05% sodium phosphate dibasic, 0.01% magnesium sulfate, 0.01% yeast extract, pH 7.0) and 0.4% of SF and the other sample containing 2 mL of liquid culture medium and 100 µL of clarified rumen fluid. The 2 samples were incubated at 40°C for 24 h. Dilutions were performed under the same conditions every 24 h until the attainment of microorganisms resistant to SF, and the finaldilution containing 50 µL of each sample was plated in the middle containing SF (0.4%) and incubated at 40°C for 24 h for the isolation of bacteria. The bacterial colonies resistant to SF were identified by morphological methods, stained, and subjected to DNA extraction sequencing using the universal primers 27f and 1492r (16S rDNA) for the identification of the bacterial genus using Blast DNA identity analysis. These bacteria were cultured with and without SF (0.4%), and the presence of fluoride ions was detected by an ion-selective electrode (fluoride) during incubation for 0, 30, 60, 90, and 120 min. Two resistant microorganisms were isolated, one was a Gram-positive coccus and the other was a Gram-positive rod. DNA sequencing identified these organisms as Enterococcus faecalis (98% identity Genbank 1358689) and Bacillus sp. (89% identity Genbank 1358671). Fluoride ions were detected more at 60-min incubation time in both E. faecalis (0.0560 ppm) and Bacillus sp. (0.0488 ppm). Bioassay protection tests were performed in mice ofthe following four groups: negative control (NC) with saline administration, positive control (PC) with administration of plant containing SF, Bacillus group (BG) with administration of plant containing SF plus Bacillus sp., and coccus group (CG) with administration of SF and E. faecalis. Clinical signs were recorded, and statistical analyses were performed to confirm the differences in the groups. Bioassay protection tests showed clinical signs of intoxication in the PC group (83.3%), BG group (100%), and CG group (16.6%) but not in the NC group (0%), with a statistical difference between GC and PC groups (P < 0.05).Discussion: Several environmental bacteria possessing dehalogenase activity have been described, such as Pseudomonas sp., Moraxella sp., and Burkholderia sp. and Pigmentiphaga kullae and Ancylobacter dichloromethanicus isolated from the rumen. No previous study has yet reported an association between dehalogenase activity and E. faecalis, and the protection assay has been observed only in the E. faecalis group. Similar results were observed in experimental intoxication in goats that had previously consumed SF, with the microorganisms identified being Pigmentiphaga kullae and Ancylobacter dichloromethanicus. E. faecalis, isolated from the bovine rumen, exhibited a dehalogenase activity, which could help control animal poisoning by plants containing SF.

Cabbage (Brassica oleracea var. capitata L.) is widely cultivated in China and be of important economic value. In October 2019, all the plants of cabbage inbred line ‘2358’ cultivated in greenhouses of the Chinese Academy of Agricultural Sciences (Beijing) were showing symptoms of leaf wilt. It usually took two weeks for the leaves to get completed wilted and the plants gradually died. It was approximately 550 plants affected, and 30 plants were collected and processed as samples. Symptomatic leaves were cut into small pieces (5×5 mm), surface sterilized with 75% ethanol for 30 s, and then sterilized with 8% NaClO for 3 mins, rinsed three times in sterile distilled water, plated on complete medium (CM: 3g Casein Enzymatic Hydrolysate + 3g Casein Acid Hydrolysate + 6g Yeast Extract+10g Sucrose + 15g Agar + 1L dH2O) and incubated at 27℃ for 6 days. Subsequently, the purified culture was obtained by tissue isolation and single-spored on CM. The colony on CM was up to about 50mm and 70mm in diameter after 4 and 7 days, respectively (Supplementary Fig. 2). At the same time, the edge of the colony gradually turned brown. Microscopic observation found that the diameter of the mycelium was about 5 µm (Supplementary Fig. 3). The conidia were transparent white and ovoid-shaped, about 0.3-0.5 µm in diameter (Supplementary Fig. 4). Fungus in liquid CM were spherical with surface hairs (Supplementary Fig. 1), which was consistent with the morphological characteristics of Chaetomium globosum. The rDNA internal transcribed spacer (ITS) of isolate ZM2019 was amplified using primers ITS1 (5’-TCCGTAGGTGAACCTGCGG-3’) and ITS4 (5’- TCCTCCGCTTATTGATATGC-3’) (Hong et al. 2013). The amplified product was sequenced and deposited in GenBank. The 573-bp amplicon (GenBank accession no. MN833403) showed a 100% homology to C. globosum isolate CES5 (MN173145). According to the morphological and molecular characterization, the fungus causing leaf blight on ‘2358’ was identified as C. globosum. In order to further distinguish the pathogen species, the β-tubulin (tub2) gene region were amplified using primers T-F (5’-CCCCTGAACTACCCCACC-3’) and T-R (5’-TATTTGACCCGACTGACC-3’) and sequenced. Finally, we further identified this pathogen as C. globosum CBS 148.51 (Wang et al. 2016), according to the blast result of the sequence (GenBank accession no. MW252170) in National Center for Biotechnology Information (NCBI). To confirm the pathogenicity of this fungus, the leaves of 12 healthy seedlings of ‘2358’ were inoculated by spraying 106 conidia/ml suspension and 12 seedlings inoculated with sterile water served as controls. All plants were incubated in a growth chamber maintained at 27℃. Ten days after inoculation, the leaves of all plants became wilted, which were consistent with the symptom in the natural state, while the control plants remained disease-free (Supplementary Fig. 6b and Fig. 6c). Subsequently, C. globosum was isolated from the inoculated seedlings again. The entire process from isolation to inoculation was repeated again and the same results were obtained. Re-isolation of C. globosum and inoculation of the host fulfiled Koch’s postulates. C. globosum has been reported previously to occur on many horticulture plants such as Punica granatum (Guo et al. 2015) and Cannabis sativa (Chaffin et al. 2020); but no brassica species has been reported so far as susceptible to C. globosum. In this sense, this is the first report of leaf blight caused by C. globosum on cabbage in China, in greenhouse condition.

Stem rust, caused by Puccinia graminis, and crown rust, caused by P. coronata, are common rust diseases on cool-season grasses (Karakkat et al. 2018), for which long-distance spore dispersal was recorded in northern US (Harder and Haber 1992). During the summers of 2019 and 2020, severe infection of stem rust and crown rust was observed on > 60% of tall fescue (Festuca arundinacea) germplasm plants in a breeding nursery located at the University of Georgia, Griffin GA. Rust-infected leaves first presented uredinia pustules, then black telia towards the end of the season. The uredinia pustules of stem rust and crown rust were brick-red and, yellow and arranged along the host veins, respectively. The urediniospores were one-celled, round to ovoid and measured from 20.75±2.44 μm (crown rust) to 27±3.60 μm long (stem rust). The teliospores were two-celled and measured from 45.75±10.14 μm (stem rust) to 51.60±4.0 μm long (crown rust) (Leonard et al. 2005; Cummins 1971). Urediniospores of both rusts were collected from infected plants in the field in April of 2020 using a Piston vacuum pump (Welch by Gardner Denver Ltd.) and stored at -80 °C in 1.5 ml Eppendorf tubes. Genomic DNA was extracted by grinding the urediniospores in liquid nitrogen using mortar and pestle, followed by the cetyltrimethylammonium bromide method (Doyle and Doyle 1987). The internal transcribed spacer (ITS) region of the ribosomal DNA was amplified using the ITS5-ITS4 primers (White et al. 1990). BLASTn and phylogenetic analyses revealed that the sequence of stem rust (GenBank acc. no. MW430963) and crown rust (GenBank acc. no. MW431324) pathogens had >99% similarity with P. graminis (GenBank acc. no. HQ317538) and P. coronata var. avenae f. sp. avenae (clade V; Liu and Hambleton 2013) (GenBank acc. no. EU014044), respectively. Pathogenicity tests were conducted on the tall fescue cultivar ‘Bandit’. For each rust, 12 pots (10 cm × 10 cm) were planted, each containing 13 seeds in a Sungro professional growing mix soil (Sun Gro Horticulture Distribution Inc.). The plant materials were kept in the greenhouse at 20°C/ 25°C (night/day),15-hrs of light, and watered twice a week for 4-weeks. Urediniospores were recovered from -80°C and allowed to acclimate at room temperature for 1 h. For each rust, 20 ml of suspension containing 1×105 urediniospores ml−1 and 5 μl of Tween-twenty (Agdia Inc. Elkhart, IN) were used to inoculate 6 pots; while 6 control pots were sprayed with sterile water. After inoculation, plants were allowed to dry for 1 h and then transferred to a dark chamber at 20°C and 90% of humidity for 12-15 h. At 10-days post inoculation, all inoculated plants developed rust symptoms identical to those observed in the field, whereas control plants had no symptoms. Stem and crown rust pathogens were re-isolated from the artificially inoculated tall fescue plants. Based on form, size, color and numbers of cells forming the spores, a 1947 Festuca elatior specimen from Georgia mentioning Puccinia coronata (Hanlin 1966), held at the Julian H. Miller Mycological Herbarium (Catalog No. GAM00013162), was discarded as an earlier record of P. coronata var. avenae and could have been misdiagnosed. Due to the fragile integrity of the original infected plant sample as well as the incipient infection, DNA identification was unsuccessful. To our knowledge, this is the first morphological, genetic and taxonomic report of P. graminis and P. coronata var. avenae f. sp. avenae on tall fescue in Georgia, USA

Ubiquitous in airports, border checkpoints, and other securitised spaces throughout the world, full-body imaging scanners claim to read bodies in order to identify if they pose security threats. Millimetre-wave body imaging machines—the most common type of body scanner—display to the operating security agent a screen with a generic body outline. If an anomaly is found or if an individual does not align with the machine’s understanding of an “average” body, a small box is highlighted and placed around the “problem” area, prompting further inspection in the form of pat-downs or questioning. In this complex security regime governed by such biometric, body-based technologies, it could be argued that nonalignment with bodily normativity as well as an attendant failure to reveal oneself—to become “transparent” (Hall 295)—marks a body as dangerous. As these algorithmic technologies become more pervasive, so too does the imperative to critically examine their purported neutrality and operative logic of revelation and readability.Biometric technologies are marketed as excavators of truth, with their optic potency claiming to demask masquerading bodies. Failure and bias are, however, an inescapable aspect of such technologies that work with narrow parameters of human morphology. Indeed, surveillance technologies have been taken to task for their inherent racial and gender biases (Browne; Pugliese). Facial recognition has, for example, been critiqued for its inability to read darker skin tones (Buolamwini and Gebru), while body scanners have been shown to target transgender bodies (Keyes; Magnet and Rodgers; Quinan). Critical security studies scholar Shoshana Magnet argues that error is endemic to the technological functioning of biometrics, particularly since they operate according to the faulty notion that bodies are “stable” and unchanging repositories of information that can be reified into code (Magnet 2).Although body scanners are presented as being able to reliably expose concealed weapons, they are riddled with incompetencies that misidentify and over-select certain demographics as suspect. Full-body scanners have, for example, caused considerable difficulties for transgender travellers, breast cancer patients, and people who use prosthetics, such as artificial limbs, colonoscopy bags, binders, or prosthetic genitalia (Clarkson; Quinan; Spalding). While it is not in the scope of this article to detail the workings of body imaging technologies and their inconsistencies, a growing body of scholarship has substantiated the claim that these machines unfairly impact those identifying as transgender and non-binary (see, e.g., Beauchamp; Currah and Mulqueen; Magnet and Rogers; Sjoberg). Moreover, they are constructed according to a logic of binary gender: before each person enters the scanner, transportation security officers must make a quick assessment of their gender/sex by pressing either a blue (corresponding to “male”) or pink (corresponding to “female”) button. In this sense, biometric, computerised security systems control and monitor the boundaries between male and female.The ability to “reveal” oneself is henceforth predicated on having a body free of “abnormalities” and fitting neatly into one of the two sex categorisations that the machine demands. Transgender and gender-nonconforming individuals, particularly those who do not have a binary gender presentation or whose presentation does not correspond to the sex marker in their documentation, also face difficulties if the machine flags anomalies (Quinan and Bresser). Drawing on a Foucauldian analysis of power as productive, Toby Beauchamp similarly illustrates how surveillance technologies not only identify but also create and reshape the figure of the dangerous subject in relation to normative configurations of gender, race, and able-bodiedness. By mobilizing narratives of concealment and disguise, heightened security measures frame gender nonconformity as dangerous (Beauchamp, Going Stealth). Although national and supranational authorities market biometric scanning technologies as scientifically neutral and exact methods of identification and verification and as an infallible solution to security risks, such tools of surveillance are clearly shaped by preconceptions and prejudgements about race, gender, and bodily normativity. Not only are they encoded with “prototypical whiteness” (Browne) but they are also built on “grossly stereotypical” configurations of gender (Clarkson).Amongst this increasingly securitised landscape, creative forms of artistic resistance can offer up a means of subverting discriminatory policing and surveillance practices by posing alternate visualisations that reveal and challenge their supposed objectivity. In his 2018 audio-video artwork installation entitled SANCTUM, UK-based American artist Zach Blas delves into how biometric technologies, like those described above, both reveal and (re)shape ontology by utilising the affectual resonance of sexual submission. Evoking the contradictory notions of oppression and pleasure, Blas describes SANCTUM as “a mystical environment that perverts sex dungeons with the apparatuses and procedures of airport body scans, biometric analysis, and predictive policing” (see full description at https://zachblas.info/works/sanctum/).Depicting generic mannequins that stand in for the digitalised rendering of the human forms that pass through body scanners, the installation transports the scanners out of the airport and into a queer environment that collapses sex, security, and weaponry; an environment that is “at once a prison-house of algorithmic capture, a sex dungeon with no genitals, a weapons factory, and a temple to security.” This artistic reframing gestures towards full-body scanning technology’s germination in the military, prisons, and other disciplinary systems, highlighting how its development and use has originated from punitive—rather than protective—contexts.In what follows, we adopt a methodological approach that applies visual analysis and close reading to scrutinise a selection of scenes from SANCTUM that underscore the sadomasochistic power inherent in surveillance technologies. Analysing visual and aural elements of the artistic intervention allows us to complicate the relationship between transparency and recognition and to problematise the dynamic of mandatory complicity and revelation that body scanners warrant. In contrast to a discourse of visibility that characterises algorithmically driven surveillance technology, Blas suggests opacity as a resistance strategy to biometrics' standardisation of identity. Taking an approach informed by critical security studies and queer theory, we also argue that SANCTUM highlights the violence inherent to the practice of reducing the body to a flat, inert surface that purports to align with some sort of “core” identity, a notion that contradicts feminist and queer approaches to identity and corporeality as fluid and changing. In close reading this artistic installation alongside emerging scholarship on the discriminatory effects of biometric technology, this article aims to highlight the potential of art to queer the supposed objectivity and neutrality of biometric surveillance and to critically challenge normative logics of revelation and readability.Corporeal Fetishism and Body HorrorThroughout both his artistic practice and scholarly work, Blas has been critical of the above narrative of biometrics as objective extractors of information. Rather than looking to dominant forms of representation as a means for recognition and social change, Blas’s work asks that we strive for creative techniques that precisely queer biometric and legal systems in order to make oneself unaccounted for. For him, “transparency, visibility, and representation to the state should be used tactically, they are never the end goal for a transformative politics but are, ultimately, a trap” (Blas and Gaboury 158). While we would simultaneously argue that invisibility is itself a privilege that is unevenly distributed, his creative work attempts to refuse a politics of visibility and to embrace an “informatic opacity” that is attuned to differences in bodies and identities (Blas).In particular, Blas’s artistic interventions titled Facial Weaponization Suite (2011-14) and Face Cages (2013-16) protest against biometric recognition and the inequalities that these technologies propagate by making masks and wearable metal objects that cannot be detected as human faces. This artistic-activist project contests biometric facial recognition and their attendant inequalities by, as detailed on the artist’s website,making ‘collective masks’ in workshops that are modelled from the aggregated facial data of participants, resulting in amorphous masks that cannot be detected as human faces by biometric facial recognition technologies. The masks are used for public interventions and performances.One mask explores blackness and the racist implications that undergird biometric technologies’ inability to detect dark skin. Meanwhile another mask, which he calls the “Fag Face Mask”, points to the heteronormative underpinnings of facial recognition. Created from the aggregated facial data of queer men, this amorphous pink mask implicitly references—and contests—scientific studies that have attempted to link the identification of sexual orientation through rapid facial recognition techniques.Building on this body of creative work that has advocated for opacity as a tool of social and political transformation, SANCTUM resists the revelatory impulses of biometric technology by turning to the use and abuse of full-body imaging. The installation opens with a shot of a large, dark industrial space. At the far end of a red, spotlighted corridor, a black mask flickers on a screen. A shimmering, oscillating sound reverberates—the opening bars of a techno track—that breaks down in rhythm while the mask evaporates into a cloud of smoke. The camera swivels, and a white figure—the generic mannequin of the body scanner screen—is pummelled by invisible forces as if in a wind tunnel. These ghostly silhouettes appear and reappear in different positions, with some being whipped and others stretched and penetrated by a steel anal hook. Rather than conjuring a traditional horror trope of the body’s terrifying, bloody interior, SANCTUM evokes a new kind of feared and fetishized trope that is endemic to the current era of surveillance capitalism: the abstracted body, standardised and datafied, created through the supposedly objective and efficient gaze of AI-driven machinery.Resting on the floor in front of the ominous animated mask are neon fragments arranged in an occultist formation—hands or half a face. By breaking the body down into component parts— “from retina to fingerprints”—biometric technologies “purport to make individual bodies endlessly replicable, segmentable and transmissible in the transnational spaces of global capital” (Magnet 8). The notion that bodies can be seamlessly turned into blueprints extracted from biological and cultural contexts has been described by Donna Haraway as “corporeal fetishism” (Haraway, Modest). In the context of SANCTUM, Blas illustrates the dangers of mistaking a model for a “concrete entity” (Haraway, “Situated” 147). Indeed, the digital cartography of the generic mannequin becomes no longer a mode of representation but instead a technoscientific truth.Several scenes in SANCTUM also illustrate a process whereby substances are extracted from the mannequins and used as tools to enact violence. In one such instance, a silver webbing is generated over a kneeling figure. Upon closer inspection, this geometric structure, which is reminiscent of Blas’s earlier Face Cages project, is a replication of the triangulated patterns produced by facial recognition software in its mapping of distance between eyes, nose, and mouth. In the next scene, this “map” breaks apart into singular shapes that float and transform into a metallic whip, before eventually reconstituting themselves as a penetrative douche hose that causes the mannequin to spasm and vomit a pixelated liquid. Its secretions levitate and become the webbing, and then the sequence begins anew.In another scene, a mannequin is held upside-down and force-fed a bubbling liquid that is being pumped through tubes from its arms, legs, and stomach. These depictions visualise Magnet’s argument that biometric renderings of bodies are understood not to be “tropic” or “historically specific” but are instead presented as “plumbing individual depths in order to extract core identity” (5). In this sense, this visual representation calls to mind biometrics’ reification of body and identity, obfuscating what Haraway would describe as the “situatedness of knowledge”. Blas’s work, however, forces a critique of these very systems, as the materials extracted from the bodies of the mannequins in SANCTUM allude to how biometric cartographies drawn from travellers are utilised to justify detainment. These security technologies employ what Magnet has referred to as “surveillant scopophilia,” that is, new ways and forms of looking at the human body “disassembled into component parts while simultaneously working to assuage individual anxieties about safety and security through the promise of surveillance” (17). The transparent body—the body that can submit and reveal itself—is ironically represented by the distinctly genderless translucent mannequins. Although the generic mannequins are seemingly blank slates, the installation simultaneously forces a conversation about the ways in which biometrics draw upon and perpetuate assumptions about gender, race, and sexuality.Biometric SubjugationOn her 2016 critically acclaimed album HOPELESSNESS, openly transgender singer, composer, and visual artist Anohni performs a deviant subjectivity that highlights the above dynamics that mark the contemporary surveillance discourse. To an imagined “daddy” technocrat, she sings:Watch me… I know you love me'Cause you're always watching me'Case I'm involved in evil'Case I'm involved in terrorism'Case I'm involved in child molestersEvoking a queer sexual frisson, Anohni describes how, as a trans woman, she is hyper-visible to state institutions. She narrates a voyeuristic relation where trans bodies are policed as threats to public safety rather than protected from systemic discrimination. Through the seemingly benevolent “daddy” character and the play on ‘cause (i.e., because) and ‘case (i.e., in case), she highlights how gender-nonconforming individuals are predictively surveilled and assumed to already be guilty. Reflecting on daddy-boy sexual paradigms, Jack Halberstam reads the “sideways” relations of queer practices as an enactment of “rupture as substitution” to create a new project that “holds on to vestiges of the old but distorts” (226). Upending power and control, queer art has the capacity to both reveal and undermine hegemonic structures while simultaneously allowing for the distortion of the old to create something new.Employing the sublimatory relations of bondage, discipline, sadism, and masochism (BDSM), Blas’s queer installation similarly creates a sideways representation that re-orientates the logic of the biometric scanners, thereby unveiling the always already sexualised relations of scrutiny and interrogation as well as the submissive complicity they demand. Replacing the airport environment with a dark and foreboding mise-en-scène allows Blas to focus on capture rather than mobility, highlighting the ways in which border checkpoints (including those instantiated by the airport) encourage free travel for some while foreclosing movement for others. Building on Sara Ahmed’s “phenomenology of being stopped”, Magnet considers what happens when we turn our gaze to those “who fail to pass the checkpoint” (107). In SANCTUM, the same actions are played out again and again on spectral beings who are trapped in various states: they shudder in cages, are chained to the floor, or are projected against the parameters of mounted screens. One ghostly figure, for instance, lies pinned down by metallic grappling hooks, arms raised above the head in a recognisable stance of surrender, conjuring up the now-familiar image of a traveller standing in the cylindrical scanner machine, waiting to be screened. In portraying this extended moment of immobility, Blas lays bare the deep contradictions in the rhetoric of “freedom of movement” that underlies such spaces.On a global level, media reporting, scientific studies, and policy documents proclaim that biometrics are essential to ensuring personal safety and national security. Within the public imagination, these technologies become seductive because of their marked ability to identify terrorist attackers—to reveal threatening bodies—thereby appealing to the anxious citizen’s fear of the disguised suicide bomber. Yet for marginalised identities prefigured as criminal or deceptive—including transgender and black and brown bodies—the inability to perform such acts of revelation via submission to screening can result in humiliation and further discrimination, public shaming, and even tortuous inquiry – acts that are played out in SANCTUM.Masked GenitalsFeminist surveillance studies scholar Rachel Hall has referred to the impetus for revelation in the post-9/11 era as a desire for a universal “aesthetics of transparency” in which the world and the body is turned inside-out so that there are no longer “secrets or interiors … in which terrorists or terrorist threats might find refuge” (127). Hall takes up the case study of Umar Farouk Abdulmutallab (infamously known as “the Underwear Bomber”) who attempted to detonate plastic explosives hidden in his underwear while onboard a flight from Amsterdam to Detroit on 25 December 2009. Hall argues that this event signified a coalescence of fears surrounding bodies of colour, genitalia, and terrorism. News reports following the incident stated that Abdulmutallab tucked his penis to make room for the explosive, thereby “queer[ing] the aspiring terrorist by indirectly referencing his willingness … to make room for a substitute phallus” (Hall 289). Overtly manifested in the Underwear Bomber incident is also a desire to voyeuristically expose a hidden, threatening interiority, which is inherently implicated with anxieties surrounding gender deviance. Beauchamp elaborates on how gender deviance and transgression have coalesced with terrorism, which was exemplified in the wake of the 9/11 attacks when the United States Department of Homeland Security issued a memo that male terrorists “may dress as females in order to discourage scrutiny” (“Artful” 359). Although this advisory did not explicitly reference transgender populations, it linked “deviant” gender presentation—to which we could also add Abdulmutallab’s tucking of his penis—with threats to national security (Beauchamp, Going Stealth). This also calls to mind a broader discussion of the ways in which genitalia feature in the screening process. Prior to the introduction of millimetre-wave body scanning technology, the most common form of scanner used was the backscatter imaging machine, which displayed “naked” body images of each passenger to the security agent. Due to privacy concerns, these machines were replaced by the scanners currently in place which use a generic outline of a passenger (exemplified in SANCTUM) to detect possible threats.It is here worth returning to Blas’s installation, as it also implicitly critiques the security protocols that attempt to reveal genitalia as both threatening and as evidence of an inner truth about a body. At one moment in the installation a bayonet-like object pierces the blank crotch of the mannequin, shattering it into holographic fragments. The apparent genderlessness of the mannequins is contrasted with these graphic sexual acts. The penetrating metallic instrument that breaks into the loin of the mannequin, combined with the camera shot that slowly zooms in on this action, draws attention to a surveillant fascination with genitalia and revelation. As Nicholas L. Clarkson documents in his analysis of airport security protocols governing prostheses, including limbs and packies (silicone penis prostheses), genitals are a central component of the screening process. While it is stipulated that physical searches should not require travellers to remove items of clothing, such as underwear, or to expose their genitals to staff for inspection, prosthetics are routinely screened and examined. This practice can create tensions for trans or disabled passengers with prosthetics in so-called “sensitive” areas, particularly as guidelines for security measures are often implemented by airport staff who are not properly trained in transgender-sensitive protocols.ConclusionAccording to media technologies scholar Jeremy Packer, “rather than being treated as one to be protected from an exterior force and one’s self, the citizen is now treated as an always potential threat, a becoming bomb” (382). Although this technological policing impacts all who are subjected to security regimes (which is to say, everyone), this amalgamation of body and bomb has exacerbated the ways in which bodies socially coded as threatening or deceptive are targeted by security and surveillance regimes. Nonetheless, others have argued that the use of invasive forms of surveillance can be justified by the state as an exchange: that citizens should willingly give up their right to privacy in exchange for safety (Monahan 1). Rather than subscribing to this paradigm, Blas’ SANCTUM critiques the violence of mandatory complicity in this “trade-off” narrative. Because their operationalisation rests on normative notions of embodiment that are governed by preconceptions around gender, race, sexuality and ability, surveillance systems demand that bodies become transparent. This disproportionally affects those whose bodies do not match norms, with trans and queer bodies often becoming unreadable (Kafer and Grinberg). The shadowy realm of SANCTUM illustrates this tension between biometric revelation and resistance, but also suggests that opacity may be a tool of transformation in the face of such discriminatory violations that are built into surveillance.ReferencesAhmed, Sara. “A Phenomenology of Whiteness.” Feminist Theory 8.2 (2007): 149–68.Beauchamp, Toby. “Artful Concealment and Strategic Visibility: Transgender Bodies and U.S. State Surveillance after 9/11.” Surveillance & Society 6.4 (2009): 356–66.———. Going Stealth: Transgender Politics and U.S. Surveillance Practices. 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