Добірка наукової літератури з теми "Anaerobic bacteria Asia"

Using morphological analysis and biochemical testing, here for the first time, we determined the culturable gut bacterial flora (aerobes and facultative anaerobes) in the venomous Black Cobra (Naja naja karachiensis) from South Asia. The findings revealed that these snakes inhabit potentially pathogenic bacteria including Serratia marcescens, Pseudomonas aeruginosa, Shewanella putrefaciens, Aeromonas hydrophila, Salmonella sp., Moraxella sp., Bacillus sp., Ochrobactrum anthropi, and Providencia rettgeri. These findings are of concern, as injury from snake bite can result in wound infections and tissue necrosis leading to sepsis/necrotizing fasciitis and/or expose consumers of snake meat/medicine in the community to infections.

The Asian Central Steppe, consisting of current-day Kazakhstan and Russia, has acted as a highway for major migrations throughout history. Therefore, describing the genetic composition of past populations in Central Asia holds value to understanding human mobility in this pivotal region. In this study, we analyse paleogenomic data generated from five humans from Kuygenzhar, Kazakhstan. These individuals date to the early to mid-18th century, shortly after the Kazakh Khanate was founded, a union of nomadic tribes of Mongol Golden Horde and Turkic origins. Genomic analysis identifies that these individuals are admixed with varying proportions of East Asian ancestry, indicating a recent admixture event from East Asia. The high amounts of DNA from the anaerobic Gram-negative bacteria Tannerella forsythia, a periodontal pathogen, recovered from their teeth suggest they may have suffered from periodontitis disease. Genomic analysis of this bacterium identified recently evolved virulence and glycosylation genes including the presence of antibiotic resistance genes predating the antibiotic era. This study provides an integrated analysis of individuals with a diet mostly based on meat (mainly horse and lamb), milk, and dairy products and their oral microbiome.

Conventional aerated tank technology is widely applied for post treatment of natural rubber processing wastewater in Southeast Asia; however, a long hydraulic retention time (HRT) is required and the effluent standards are exceeded. In this study, a downflow hanging sponge (DHS) reactor was installed as post treatment of anaerobic tank effluent in a natural rubber factory in South Vietnam and the process performance was evaluated. The DHS reactor demonstrated removal efficiencies of 64.2 ± 7.5% and 55.3 ± 19.2% for total chemical oxygen demand (COD) and total nitrogen, respectively, with an organic loading rate of 0.97 ± 0.03 kg-COD m−3 day−1 and a nitrogen loading rate of 0.57 ± 0.21 kg-N m−3 day−1. 16S rRNA gene sequencing analysis of the sludge retained in the DHS also corresponded to the result of reactor performance, and both nitrifying and denitrifying bacteria were detected in the sponge carrier. In addition, anammox bacteria was found in the retained sludge. The DHS reactor reduced the HRT of 30 days to 4.8 h compared with the existing algal tank. This result indicates that the DHS reactor could be an appropriate post treatment for the existing anaerobic tank for natural rubber processing wastewater treatment.

Seven strains of purple nonsulfur bacteria isolated from the shallow-water steppe soda lakes of the cryoarid zone of Central Asia formed a genetically homogeneous group within the genus Rhodovulum. The isolates were most closely related to Rhodovulum strictum, from which they differed at the species level (99.5 % 16S rRNA gene identity and 42–44 % DNA–DNA hybridization level). According to genotypic and phenotypic characteristics, the strains were assigned to a new species of the genus Rhodovulum, for which the name Rhodovulum steppense sp. nov. is proposed. Cells of all strains were ovoid to rod-shaped, 0.3–0.8 μm wide and 1–2.5 μm long, and motile by means of polar flagella. They contained internal photosynthetic membranes of the vesicular type and photosynthetic pigments (bacteriochlorophyll a and carotenoids of the spheroidene series). All strains were obligate haloalkaliphiles, growing within a wide range of salinity (0.3–10 %) and pH (7.5–10), with growth optima at 1–5 % NaCl and pH 8.5. Photo- and chemoheterotrophic growth occurred with a number of organic compounds and biotin, thiamine and niacin as growth factors. No anaerobic respiration on nitrite, nitrate or fumarate and no fermentation was demonstrated. Bacteria grew photo- and chemolithoautotrophically with sulfide, sulfur and thiosulfate, oxidizing them to sulfate. Sulfide was oxidized via deposition of extracellular elemental sulfur. No growth with H2 as electron donor was demonstrated. The major fatty acid was 18 : 1 (81.0 %). The major quinone was Q-10. The DNA G+C content was 66.1 mol% (T m). The type strain, A-20sT (=VKM B-2489T =DSM 21153T), was isolated from soda lake Khilganta (Zabaikal'skii Krai, southern Siberia, Russia).

A staggering 4000 million people cannot digest lactose, the sugar in milk, properly. All mammals, apart from white Northern Europeans and few tribes in Africa and Asia, lose most of their lactase, the enzyme that cleaves lactose into galactose and glucose, after weaning. Lactose intolerance causes gut and a range of systemic symptoms, though the threshold to lactose varies considerably between ethnic groups and individuals within a group. The molecular basis of inherited hypolactasia has yet to be identified, though two polymorphisms in the introns of a helicase upstream from the lactase gene correlate closely with hypolactasia, and thus lactose intolerance. The symptoms of lactose intolerance are caused by gases and toxins produced by anaerobic bacteria in the large intestine. Bacterial toxins may play a key role in several other diseases, such as diabetes, rheumatoid arthritis, multiple sclerosis and some cancers. The problem of lactose intolerance has been exacerbated because of the addition of products containing lactose to various foods and drinks without being on the label. Lactose intolerance fits exactly the illness that Charles Darwin suffered from for over 40 years, and yet was never diagnosed. Darwin missed something else – the key to our own evolution – the Rubicon some 300 million years ago that produced lactose and lactase in sufficient amounts to be susceptible to natural selection.

Clostridium difficile is an anaerobic bacil gram-positive bacteria, able to form spores and toxin, that is transmitted among humans through the fecal–oral route. Clostridium difficile infection (CDI), a typical nosocomial infection has been contributed to a signifi cant proportion of morbidity and mortality among in-patients with a case-fatality rate of 14% within 30 days after diagnosis. Profound culture and toxin examination for C. difficile are still minimal in many hospitals in various Asian countries. Consequently, C. difficile reports in Asia remain rare. Highly virulent form of C. difficile caused greater fatality and epidemics severity. Elderly age, hospitalization, exposure to antibiotics e.g., cephalosporins, fluoroquinolones, clindamycin, and penicillin contributed as main risk factors. Hypervirulent strain BI/NAP1/027 demonstrated to carry CdtLoc gene locus encodes CD196 ADP-ribosyltransferase (CDT) or known as binary toxin. Virulence factors are TcdA, TcdB, CDTa CDTb in which hypersporulation and mutation of TcD gene by hypervirulent strain led to toxin hyperexpression. Early cases detection, building management team to evaluate patient positive with all C. difficile toxins, hand hygiene improvement, continuation of contact precautions after diarrhea resolution, audit of infection control, and restriction of antimicrobials should be implemented as preventative measures. Focus measures also should emphasize on development of vaccine of C. difficile to boost immune state of elderly people. This review aims to describe severity of disease caused by hypervirulent BI/NAP1/027 C. difficile strain, its mechanism or pathogenesis, risk factors, current treatment options available, along with proposed preventative measures and infection control.

Anaerobic enrichments with acetate as electron donor and nitrate as electron acceptor at 4 M NaCl from inland, hypersaline lake sediments from Central Asia resulted in the isolation of several extremely halophilic bacteria that comprised two subgroups, most with vibrio-shaped cells and a single strain with rod-shaped cells. Members of both subgroups were extremely halophilic, with growth occurring in 2–5 M NaCl with an optimum at 2–3 M. 16S rRNA gene sequence analysis showed a close affiliation of the new isolates with Pseudomonas halophila DSM 3050 in the Gammaproteobacteria. However, phenotypic comparison of the denitrifying halophiles with the original description of P. halophila demonstrated that they were more similar to another bacterium isolated from the same source at the same time, the extremely halophilic Halovibrio variabilis, which has since been reclassified as Halomonas variabilis (DSM 3051). Direct cross-comparison showed that the characteristics of these two halophilic bacteria do not correspond with the original descriptions associated with these names and DSM numbers. While it is desirable that this problem be solved, in connection with the present investigations, this is a matter that can only be solved by a Request for an Opinion. On the basis of the phenotypic and genetic comparison of these isolates, it is proposed that the new denitrifying vibrio-shaped isolates represent a novel species, Halovibrio denitrificans sp. nov. (type strain HGD 3T=DSM 15503T=UNIQEM U232T) and that the rod-shaped isolate represents a novel genus and species, Halospina denitrificans gen. nov., sp. nov. (type strain HGD 1-3T=DSM 15505T=UNIQEM U233T).

Study on ammonia nitrogen and phosphorus removal using sequencing batch reactor Samaneh Alijantabar Aghouzi * Department of Chemical and Environmental Engineering, Faculty of Engineering Universiti Putra Malaysia, Serdang Malaysia Thomas S. Y. Choong Sustainable Process Engineering Research Center (SPERC) Universiti Putra Malaysia, Serdang Malaysia Aida Isma M. I. Centre for Water Research, Faculty of Engineering and the Built Environment SEGi University, Kota Damansara Malaysia *Corrosponding author’s Email: sam.alijani@gmail.com Peer-review under responsibility of 3rd Asia International Multidisciplanry Conference 2019 editorial board (http://www.utm.my/asia/our-team/) © 2019 Published by Readers Insight Publisher, lat 306 Savoy Residencia, Block 3 F11/1,44000 Islamabad. Pakistan, info@readersinsight.net This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). _________________________________________________________ Research Highlights The highest phosphorus and ammonia nitrogen removal efficiencies were 99.5% and 51%, respectively, in 6 hours. Particle size of sludge reduced from 26 μm to 39.81 μm in 60 days. Fourier transform infrared spectroscopy (FTIR) showed that N-O, N–H, S=O and C=N compunds detected. ___________________________________________________________________________ Research Objectives Ammonia nitrogen and phosphorus removal have becoming more rigorous in permits making it one of the most important and most difficult processes to maintain in wastewater treatment plants. Sequencing batch reactor is a controlled activated sludge process that is able to tackle ammonia nitrogen and phosphorus issues and has some benefits such as having a small-scale system and low construction cost (1). The main goal of this research is to investigate the ability of SBR in treating sewage containing phosphorus and ammonia nitrogen in 6 hours to achieve the allowable effluent discharge standard set by the Department of Environment Malaysia. Materials and Methods In this experiment, a sequencing batch reactor with a total volume of 7 L. The mechanical stirrer was used to avoid sludge settling with a speed of 100 rpm. A fine bubble diffuser was used to supply air. The operation time was controlled based on 1 h and 30 mins anaerobic, 2 h and 10 mins anoxic, 1 h and 50 mins aerobic, making the hydraulic retention time (HRT) of 6 hours. 10 L seed sludge and 30 L raw sewage samples were collected weekly from the sewage treatment plant that was located in Selangor and were kept under 4oC in cold room in order to obtain fresh samples. The sludge volume was 30% of raw sewage volume in the reactor and the reactor refilled with 3.5 liters of raw sewage at the start point of the experiment. The experiment was carried out in room temperature of 27±3 oC with the pH value ranging from 6 to 8 and dissolve oxygen value ranging from 0 to 6 mg/L. Phosphorus and ammonia nitrogen were measured according to the APHA method (2). DO and PH were measured by using DO meter (JPB-70A) and PH meter (CT-6821, Shenzhen Kedida Electronic CO). Results The highest ammonia nitrogen removal efficiencies observed to be 31.9 %, 10.3 % and 38.8 % at the respective phases of anaerobic, anoxic and aerobic, respectively. Results showed that the phosphorus removal efficiencies for anaerobic, anoxic and aerobic phases were 70.43 %, 19.16%, and 98.58%, respectively in 6 hours. The highest phosphorus removal efficiency recorded was 98.58% that took place in the aerobic phase because of the absence of sufficient nitrate which can inhibit phosphorus uptake during the aerobic phase. The most sensitive process is nitrification that helps to biological oxidation of ammonia to nitrate, which is performed by two types of microorganisms, i.e. ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) (3). Karl et al. claimed that toxic substances inhibit the metabolism of bacteria (4). Mino et al. (5) also stated that nitrification process will not be accomplished in anaerobic phase without the presence of nitrate. This will affect the phosphorus uptake in the aeration phase. Findings FTIR spectrum shows that N-O, N–H, S=O and C=N compounds were identified in the sludge. The presence of these compounds might affect the nitrification and denitrification processes and indirectly affecting the degradation the ammonia nitrogen and phosphorus. Sewage sample might also contain heavy metals as the sewage treatment plant was located in the industrial area. Acknowledgment The authors gratefully thank the financial and research support of Universiti Putra Malaysia. References Sathian, S, M Rajasimman, C S Rathnasabapathy, and C Karthikeyan. 2014. “Journal of Water Process Engineering Performance Evaluation of SBR for the Treatment of Dyeing Wastewater by Simultaneous Biological and Adsorption Processes.” Journal of Water Process Engineering 4: 82–90. APHA. Standard Methods For the examination of water and Wastewater 23rd ed. ed. Washington, D.C.2017. Chang HN, Moon RK, Park BG, Lim S, Choi DW. Simulation of sequential batch reactor ( SBR ) operation for simultaneous removal of nitrogen and phosphorus. 2000;23. Karl DM, States U. Nitrogen Cycle ☆. 3rd ed. Encyclopedia of Ocean Sciences, 3rd Edition. Elsevier Inc.; 2018. 1-10 p. Mino T, Loosdrecht MCM van, Heijnen JJ. Microbiology and biochemistry of the EBPR process. Water Res. 1998;32(11):3193–207.

The bidara plant (Ziziphus mauritiana Lam) is widely distributed in various Asian countries. Bidara leaves contain secondary metabolites, the main content of which is flavonoids. As a gram-negative anaerobic bacteria, Porphyromonas gingivalis is one of the normal flora of the oral cavity. However, over quantities of this bacteria can promote chronic periodontitis. This research aims to analyze the bidara leaf ethanolic extract as an inhibitory agent of Porphyromonas gingivalis. This research design is experimental laboratory research with a post-test controlled group of Porphyromonas gingivalis inhibition. A total of 25 samples consisted of 5 groups of ethanol extract of bidara leaves at concentrations of 1%, 3%, 9%, positive control betel leaves, and negative control aquadest. Bacteria incubation was held for 48 hours, and the free bacterial zone was analyzed by the One Way ANOVA test. The results of the analysis showed that there was a significant difference between the control group and the treatment group. This study concludes that the ethanol extract of bidara leaves had a strong inhibitory effect on Porphyromonas gingivalis.

The article presents the results of studies of systems with natural aeration (NAS) used for the treatment of domestic wastewater in the countries of Central Asia, both in cities and in small settlements. NAS of artificial and natural origin, with depths of 2.0-4.0 m were studied. It was shown that in their hydrological characteristics NAS are close to natural reservoirs of the lake-pond complex - eutrophic lakes. It has been established that during the operation bottom sediments accumulate in them, the greatest thickness of which is noted in the initial part of the NAS. The formation of bottom sediments occurs under anaerobic conditions with the active participation of bacterial microflora in the processes of mineralization. In terms of moisture, ash content and organic matter content, NAS bottom sediments are similar to sapropels of eutrophic lakes.

Abstract Both high cost and environmental load of surfactant are issues to be solved in foam EOR. Moreover, it is difficult to control the injection of surfactant and gas so that the foam is generated in only high permeable zones selectively in oil reservoir. The authors have found a foam generating microorganism and hit upon an idea of the microbial foam EOR which makes the microorganism do generating foam in oil reservoir. The mechanism of the microbial foam generation and culture condition suitable for the foam generation were studied in this study. A species of Pseudomonas aeruginosa was used as a foam producer in this study. It was cultured in the medium consisting of glucose and eight kinds of minerals at 30 °C and atmospheric pressure under anaerobic conditions. Because P. aeruginosa generally grows better under aerobic conditions, the microorganism was supplied with oxygen nanobubbles as the oxygen source. The carbon dioxide nanobubbles were also used as a comparison target in this study. The state of foam generation in the culture solution was observed during the cultivation. The surface tension, surfactant concentration, protein concentration, polysaccharides concentration and bacterial population of the culture solution were measured respectively. The foam was started to be generated by the microorganism after 2 days of cultivation and its volume became maximum after 3 days of cultivation. The foam generation was found in the culture solution which contained both oxygen nanobubbles and carbon dioxide nanobubbles whereas little foam was found in non-nanobubbles culture solution. The foam generation found in the culture solution containing carbon dioxide nanobubbles was more than that in the culture solution containing oxygen nanobubbles. Both gas and protein concentration increased along with the formation of the foam whereas surfactant and polysaccharides were not increased, therefore, the foam was assumed to be generated with gas and protein which were generated by P. aeruginosa. It was found that the carbon dioxide nanobubbles were positively charged in the culture medium whereas they were negatively charged in tap water through the measurement of zeta potential of nanobubbles, therefore, the carbon dioxide nanobubbles attracted cations in the culture medium and became positively charged. Positively charged carbon dioxide nanobubbles transported cations to the microbial cells of P. aeruginosa. Among cations in the culture medium, ferrous ions are essential for the protein generation of P. aeruginosa, therefore, the positively charged carbon dioxide nanobubbles attracted ferrous ions and transport them to the microbial cells, resulting the growth and metabolism of P. aeruginosa were activated. Those results suggest that the microbial foam EOR can be materialized by supplying the microorganism with carbon dioxide nanobubbles or ferrous ions.

Abstract The foam improves heterogeneity of permeability in oil reservoir and contributes to enhancing oil recovery. Both surfactant and gas are alternatingly injected into oil reservoir in foam EOR, therefore, it has several challenges: high cost of surfactant, formation of precipitation with bivalent cations, adsorption of surfactant on reservoir rock, etc. This study proposes the microbial foam EOR which overcomes those challenges by having microorganism generate foam in-situ. We have found an ability of a microorganism belonging to Pseudomonas aeruginosa to generate foam under anaerobic conditions. This study investigated the source materials constructing the foam and capacity of the foam to improve the heterogeneity of the permeability. The challenges of our study are the reproducibility of the foam generation and the foam stability. This study therefore examined the source materials of the foam to understand the mechanisms of the foam generation. We focused on protein, which has been suggested as a possible component of the foam in our previous studies, and examined the relationship between the amount of foam generated by P. aeruginosa and the concentration of protein in its culture solution. As a result, a positive correlation was found between them. This result indicates that the foam generated by P. aeruginosa is composed of the protein produced by the microorganism. Next, the performance of the foam decreasing permeability of high permeability porous media was evaluated through sand pack flooding experiment. P. aeruginosa was injected into a sand pack and cultivated in-situ. The post-flush water was injected into the sand pack after three days’ in-situ cultivation to measure the permeability. As a result, the permeability of the sand pack was successfully decreased to half after the cultivation. The permeability of a sand pack in which P. aeruginosa was injected with culture medium and in-situ cultivated was successfully decreased to half of initial. The efflux of bacterial cells of P. aeruginosa was detected after injecting 1.3 pore volumes of postflush water, which shows that the postflush water flowed through areas other than the area where P. aeruginosa grew and produced the foam. These results indicate that the foam produced in-situ by P. aeruginosa is effective for improving the heterogeneity of permeability in oil reservoir. This EOR can be operated at low cost without expensive chemicals. Because the foam produced by P. aeruginosa is induced by proteins, the precipitation will not be formed in oil reservoir. The stability of protein-induced foam is higher than that of surfactant-induced foam in the presence of oil or high saline conditions. The microbial foam EOR therefore has high potential improving the heterogeneity of permeability in oil reservoir more effectively than the conventional foam EOR.