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1
Adaskaveg, James E., Helga Förster, Layne Wade, David F. Thompson, and Joseph H. Connell. "Efficacy of Sodium Tetrathiocarbonate and Propiconazole in Managing Armillaria Root Rot of Almond on Peach Rootstock." Plant Disease 83, no. 3 (March 1999): 240–46. http://dx.doi.org/10.1094/pdis.1999.83.3.240.
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The efficacy of sodium tetrathiocarbonate (STTC or Enzone 31.8%, a liquid formulation that releases carbon disulfide) and the demethylation inhibiting (DMI) fungicide propiconazole (Alamo 1.1EC) was evaluated for management of Armillaria root rot of almond grown on Lovell peach rootstock. After 12 months, pre-/post-plant STTC (189 liters of 3,850 and 500 mg/liter/3 m2 treatment site, respectively) or tarped pre-plant methyl bromide (Dowfume 98%, 454 g a.i./3 m2) soil fumigation treatments significantly (P < 0.05) reduced the recovery of Armillaria mellea from naturally infected root segments at 0.3 and 1.2 m soil depths, compared with control sites. Tarped methyl bromide treatments eradicated the fungus from infested root segments at both depths; however, nontarped sites significantly reduced the recovery only at the 1.2 m depth. Pre-plant STTC (189 liters of 3,850 mg/liter/3 m2) reduced the recovery of the fungus but was not as effective as the pre-/post-plant STTC treatment. Recovery of the fungus in post-plant treatments with STTC (189 liters of 500 mg/liter/3 m2) was not significantly (P > 0.05) different from control sites. Additionally, mortality of almond tree replants from phytotoxicity was significantly higher in post-plant applications of STTC, compared with the other treatments or with the control trees. A gel formulation of 31.8% STTC (1,800 ml of 318,000 mg of STTC per liter per tree stump) applied in wells that were drilled into tree stumps eradicated the fungus from trunk and primary roots but not secondary or tertiary roots, whereas liquid formulations of STTC and metam-sodium (Vapam - 32.7% sodium N-methyldithiocarbamate) eradicated the fungus from only trunks but not roots. Treatments with STTC (189 liters of 500 mg/liter/3 m2) were not effective in preventing mortality of A. mellea-infected, mature, 7- to 8-year-old almond trees. Propiconazole (Alamo 1.1EC) was shown to be toxic to mycelial growth of A. mellea grown on potato dextrose agar with an EC50 value of 0.15 mg/liter. Therapeutic, passive injections of propiconazole into 7- to 8-year-old almond trees (Lovell peach rootstock) were successful in reducing mortality of infected trees during two growing seasons, compared with infected control trees treated with water.
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Morales-Morales, Hugo A., Guadalupe Vidal, John Olszewski, Channah M. Rock, Debanjana Dasgupta, Kevin H. Oshima, and Geoffrey B. Smith. "Optimization of a Reusable Hollow-Fiber Ultrafilter for Simultaneous Concentration of Enteric Bacteria, Protozoa, and Viruses from Water." Applied and Environmental Microbiology 69, no. 7 (July 2003): 4098–102. http://dx.doi.org/10.1128/aem.69.7.4098-4102.2003.
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ABSTRACT The detection and identification of pathogens from water samples remain challenging due to variations in recovery rates and the cost of procedures. Ultrafiltration offers the possibility to concentrate viral, bacterial, and protozoan organisms in a single process by using size-exclusion-based filtration. In this study, two hollow-fiber ultrafilters with 50,000-molecular-weight cutoffs were evaluated to concentrate microorganisms from 2- and 10-liter water samples. When known quantities (105 to 106 CFU/liter) of two species of enteric bacteria were introduced and concentrated from 2 liters of sterile water, the addition of 0.1% Tween 80 increased Escherichia coli strain K-12 recoveries from 70 to 84% and Salmonella enterica serovar Enteritidis recoveries from 36 to 72%. An E. coli antibiotic-resistant strain, XL1-Blue, was recovered at a level (87%) similar to that for strain K-12 (96%) from 10 liters of sterile water. When E. coli XL1-Blue was introduced into 10 liters of nonsterile Rio Grande water with higher turbidity levels (23 to 29 nephelometric turbidity units) at two inoculum levels (9 × 105 and 2.4 × 103 per liter), the recovery efficiencies were 89 and 92%, respectively. The simultaneous addition of E. coli XL1-Blue (9 × 105 CFU/liter), Cryptosporidium parvum oocysts (10 oocysts/liter), phage T1 (105 PFU/liter), and phage PP7 (105 PFU/liter) to 10 liters of Rio Grande surface water resulted in mean recoveries of 96, 54, 59, and 46%, respectively. Using a variety of surface waters from around the United States, we obtained recovery efficiencies for bacteria and viruses that were similar to those observed with the Rio Grande samples, but recovery of Cryptosporidium oocysts was decreased, averaging 32% (the site of collection of these samples had previously been identified as problematic for oocyst recovery). Results indicate that the use of ultrafiltration for simultaneous recovery of bacterial, viral, and protozoan pathogens from variable surface waters is ready for field deployment.
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Gumbo, Tawanda. "New Susceptibility Breakpoints for First-Line Antituberculosis Drugs Based on Antimicrobial Pharmacokinetic/Pharmacodynamic Science and Population Pharmacokinetic Variability." Antimicrobial Agents and Chemotherapy 54, no. 4 (January 19, 2010): 1484–91. http://dx.doi.org/10.1128/aac.01474-09.
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ABSTRACT Arguably, one of the most common and consequential laboratory tests performed in the world is Mycobacterium tuberculosis susceptibility testing. M. tuberculosis resistance is defined by growth of ≥1% of a bacillary inoculum on the critical concentration of an antibiotic. The critical concentration was chosen based on inhibition of ≥95% of wild-type isolates. The critical concentration of isoniazid is either 0.2 or 1.0 mg/liter, that of rifampin is 1.0 mg/liter, that of pyrazinamide is 100 mg/liter, that of ethambutol is 5.0 mg/liter, and that of fluoroquinolones is 1.0 mg/liter. However, the relevance of these concentrations to microbiologic and clinical outcomes is unclear. Critical concentrations were identified using the ability to achieve the antibiotic area under the concentration-time curve/MIC ratio associated with ≥90% of maximal kill (EC90) of M. tuberculosis in ≥90% of patients. Population pharmacokinetic parameters and their variability encountered in tuberculosis patients were utilized in Monte Carlo simulations to determine the probability that particular daily doses of the drugs would achieve or exceed the EC90 in the epithelial lining fluid of 10,000 tuberculosis patients. Failure to achieve EC90 in ≥90% of patients at a particular MIC was defined as drug resistance. The critical concentrations of moxifloxacin and ethambutol remained unchanged, but a critical concentration of 50 mg/liter was identified for pyrazinamide, 0.0312 mg/liter and 0.125 mg/liter were defined for low- and high-level isoniazid resistance, respectively, and 0.0625 mg/liter was defined for rifampin. Thus, current critical concentrations of first-line antituberculosis drugs are overoptimistic and should be set lower. With the proposed breakpoints, the rates of multidrug-resistant tuberculosis could become 4-fold higher than currently assumed.
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MARKAKI, P., C. DELPONT-BINET, F. GROSSO, and S. DRAGACCI. "Determination of Ochratoxin A in Red Wine and Vinegar by Immunoaffinity High-Pressure Liquid Chromatography." Journal of Food Protection 64, no. 4 (April 1, 2001): 533–37. http://dx.doi.org/10.4315/0362-028x-64.4.533.
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A method is described for the determination of ochratoxin A (OTA) in red wine and vinegar using an acidic chloroform extraction, an immmunoaffinity clean-up step, and a high-performance liquid chromatographic determination with fluorescence detection. The detection limit was estimated at 0.002 μg/liter. The mean recovery factors were found at 91.3 and 96.6% for wine and vinegar, respectively. Thirty-one samples of red wine originating from Mediterranean sea countries and 15 samples of vinegar were examined for the presence of OTA. All red wine samples contained OTA. Seventy-two percent of these samples were found to be contaminated over 0.1 μg/liter. Among them, nine samples contained ochratoxin A in the range of 0.5 to 3.4 μg/liter, 12 samples in the range of 0.10 to 0.50 μg/liter (median: 0.176 μg/liter), and 9 samples in the range of 0.010 to 0.100 μg/liter (median: 0.041 μg/liter). All 15 vinegar samples showed the presence of OTA. The most contaminated ones were three balsamic vinegar samples containing 0.156 μg/liter, 0.102 μg/liter, and 0.252 μg/liter of OTA. In the remaining 12 samples, ochratoxin A levels ranged from 0.008 μg/liter to 0.046 μg/liter (median: 0.012 μg/liter). These data are in good agreement with the hypothesis that wine originating from Southern countries might contain significant OTA concentration and showed the possible occurrence of traces of OTA in vinegar.
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Schutte, G. C., R. I. Mansfield, H. Smith, and K. V. Beeton. "Application of Azoxystrobin for Control of Benomyl-Resistant Guignardia citricarpa on ‘Valencia’ Oranges in South Africa." Plant Disease 87, no. 7 (July 2003): 784–88. http://dx.doi.org/10.1094/pdis.2003.87.7.784.
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Azoxystrobin was evaluated in replicated small-plot trials from 1995 to 1999 for control of citrus black spot (CBS) on ‘Valencia’ oranges caused by Guignardia citricarpa. Applications of different rates of tank mixes of azoxystrobin and mancozeb during the susceptible period from October to January were compared with an untreated control as well as the standard four applications of mancozeb with or without mineral oil (1.20 g a.i./liter + 0.5% [vol/vol]/liter and 1.60 g a.i./liter of water, respectively). Two applications of azoxystrobin in tank mixtures with mancozeb and mineral oil (0.5% [vol/vol]/liter) in mid-November and mid-January at rates of 0.10, 0.15, and 0.20 g a.i./liter controlled CBS by more than 98 to 99%, 99 to 100% and 95 to 98%, respectively. Concomitantly, where mineral oil was not added to the fungicide mixture, azoxystrobin and mancozeb resulted only in 73 to 95%, 74 to 93% and 92.2 to 92.3% CBS control, respectively. Tank mixtures of benomyl, mancozeb, and mineral oil reduced CBS by only 29%, which could be attributed to the presence of benomyl-resistant pathogen isolates in the experimental orchard. Azoxystrobin applied at rates of 0.05, 0.075, and 0.10 g a.i./liter in tank mixtures with mancozeb (1.2 g a.i./liter) and mineral oil (0.5% [vol/vol]/liter of water) or Agral 90 (0.5% [vol/vol]/liter of water) were equally effective, reducing CBS by more than 99%. When mineral oil was compared to different adjuvants in tank mixtures with azoxystrobin and mancozeb, only mineral oil resulted in 100% clean exportable fruit. There was no difference between Sunspray 6E and Bac oil when mixed with azoxystrobin and mancozeb on the degree of disease control. Furthermore, the concentration of mineral oil in water can be lowered from 0.5% (vol/vol)/liter of water to 0.3% (vol/vol)/liter of water without a loss in efficacy against CBS. It is therefore, recommended that azoxystrobin (0.075 g a.i./liter) must be applied in tank mixtures with mancozeb (1.2 g a.i./liter) and mineral oil, which can be applied at either 0.5% (vol/vol)/liter of water or 0.3% (vol/vol)/liter of water.
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Pouillot, Régis, Jane M. Van Doren, Jacquelina Woods, Daniel Plante, Mark Smith, Gregory Goblick, Christopher Roberts, et al. "Meta-Analysis of the Reduction of Norovirus and Male-Specific Coliphage Concentrations in Wastewater Treatment Plants." Applied and Environmental Microbiology 81, no. 14 (May 1, 2015): 4669–81. http://dx.doi.org/10.1128/aem.00509-15.
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ABSTRACTHuman norovirus (NoV) is the leading cause of foodborne illness in the United States and Canada. Wastewater treatment plant (WWTP) effluents impacting bivalve mollusk-growing areas are potential sources of NoV contamination. We have developed a meta-analysis that evaluates WWTP influent concentrations and log10reductions of NoV genotype I (NoV GI; in numbers of genome copies per liter [gc/liter]), NoV genotype II (NoV GII; in gc/liter), and male-specific coliphage (MSC; in number of PFU per liter), a proposed viral surrogate for NoV. The meta-analysis included relevant data (2,943 measurements) reported in the scientific literature through September 2013 and previously unpublished surveillance data from the United States and Canada. Model results indicated that the mean WWTP influent concentration of NoV GII (3.9 log10gc/liter; 95% credible interval [CI], 3.5, 4.3 log10gc/liter) is larger than the value for NoV GI (1.5 log10gc/liter; 95% CI, 0.4, 2.4 log10gc/liter), with large variations occurring from one WWTP to another. For WWTPs with mechanical systems and chlorine disinfection, mean log10reductions were −2.4 log10gc/liter (95% CI, −3.9, −1.1 log10gc/liter) for NoV GI, −2.7 log10gc/liter (95% CI, −3.6, −1.9 log10gc/liter) for NoV GII, and −2.9 log10PFU per liter (95% CI, −3.4, −2.4 log10PFU per liter) for MSCs. Comparable values for WWTPs with lagoon systems and chlorine disinfection were −1.4 log10gc/liter (95% CI, −3.3, 0.5 log10gc/liter) for NoV GI, −1.7 log10gc/liter (95% CI, −3.1, −0.3 log10gc/liter) for NoV GII, and −3.6 log10PFU per liter (95% CI, −4.8, −2.4 PFU per liter) for MSCs. Within WWTPs, correlations exist between mean NoV GI and NoV GII influent concentrations and between the mean log10reduction in NoV GII and the mean log10reduction in MSCs.
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WARD, PAULA MARIE L. "Brown and Black Grease Suitability for Incorporation into Feeds and Suitability for Biofuels." Journal of Food Protection 75, no. 4 (April 1, 2012): 731–37. http://dx.doi.org/10.4315/0362-028x.jfp-11-221.
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Waste grease lipids used in animal feeds have been the cause of food recalls in Europe, where such materials were incorporated into animal feedstuffs. This resulted in unwanted residues in human food. The composition of such lipid sources has been lacking. Seventeen composite trap grease and isolated brown grease samples were analyzed. Analytes included nutrients, metals, and volatile organic compounds. Analytes were selected for relevance to wastewater treatment and resource reuse potential. Moisture averaged 89.4% and the pH was 3.8. The 5-day biological oxygen demand was 32,531 mg/liter, solids were 7.5%, and fats, oil, and grease were 48,970 mg/liter. Non–polychlorinated biphenyl volatile organic compounds were surveyed. In the 17 grease samples, 14 contained an average of 102.5 μg/liter chloroform; 11 samples contained acetone, averaging 369 μg/liter; 9 samples contained 2-butanone, with an average of 484 μg/liter; and 8 contained an average of 710 μg/liter methylene chloride and toluene at 311 μg/liter. The mean concentration of copper in 17 composite samples ranged from 15 to 239 mg/liter, iron averaged 314 mg/liter, lead means ranged from 2.5 to 24 mg/liter, and magnesium averaged 975 mg/liter. It is hypothesized that food preparation facility cleaning and chlorinated cleaning–disinfection agents combined with the organics in the low-pH environment of the traps produce potentially carcinogenic compounds. It is recommended that these waste grease materials be used as a feedstock for biofuel.
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Burgess, Treena, Jen McComb, Giles Hardy, and Ian Colquhoun. "Influence of Low Oxygen Levels in Aeroponics Chambers on Eucalypt Roots Infected with Phytophthora cinnamomi." Plant Disease 82, no. 4 (April 1998): 368–73. http://dx.doi.org/10.1094/pdis.1998.82.4.368.
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Aeroponics root chambers were designed to evaluate the influence of low oxygen on disease development in clones of Eucalyptus marginata susceptible or resistant to infection by Phytophthora cinnamomi. Actively growing 7-month-old clones of E. marginata were transferred into the aeroponics chambers, into which a nutrient solution was delivered in a fine spray, providing optimal conditions for root growth. Prior to inoculation by zoospores of P. cinnamomi under normal oxygen, the roots were exposed to four treatments: (i) normal oxygen, approximately 8 mg of O2 liter-1; (ii) 6 days of hypoxia, 2 mg of O2 liter-1; (iii) anoxic acclimatization 2 days at 2 mg of O2 liter-1, 2 days at 1 mg of O2 liter-1, 2 days at 0.5 mg of O2 liter-1, 2 days at 2 mg of O2 liter-1, and 6 h at <0.05 mg of O2 liter-1; and (iv) 6 h of anoxia, <0.05 mg of O2 liter-1. Root extension during hypoxia was greatly reduced. Lesion development was least for roots exposed to hypoxia and greatest for roots exposed to anoxia for 6 h, suggesting increased resistance of E. marginata to P. cinnamomi following hypoxia.
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LAVIZZARI, T., M. BRECCIA, S. BOVER-CID, M. C. VIDAL-CAROU, and M. T. VECIANA-NOGUÉS. "Histamine, Cadaverine, and Putrescine Produced In Vitro by Enterobacteriaceae and Pseudomonadaceae Isolated from Spinach." Journal of Food Protection 73, no. 2 (February 1, 2010): 385–89. http://dx.doi.org/10.4315/0362-028x-73.2.385.
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A total of 364 bacterial isolates, obtained from spinach leaves, were assayed in a decarboxylase broth containing histidine, lysine, and ornithine to check their ability to produce biogenic amines, and then quantified by high-performance liquid chromatography. Among these isolates, 240 formed cadaverine, 208 formed putrescine, and 196 formed histamine, in widely varying amounts. They frequently produced more than one biogenic amine. Klebsiella pneumoniae subsp. pneumoniae and Morganella morganii were the main histamine producers, with mean values of 1,600 and 2,440 mg/liter, respectively, followed by Pantoea spp. 3 (1,710 mg/liter) and Hafnia alvei (2,500 mg/liter). Enterobacter amnigenus and Enterobacter cloacae produced particularly high amounts of putrescine, with mean values of 2,340 and 2,890 mg/liter, respectively. The strongest cadaverine formation was shown by Serratia liquefaciens (3,300 mg/liter), Serratia marcescens (3,280 mg/liter), and Stenotrophomonas maltophilia (1,000 mg/liter).
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OH, MYEONGGEUN, JOONGJAE LEE, YOONHWA JEONG, and MISOOK KIM. "Synergistic Antilisterial Effects of Mixtures of Lysozyme and Organic Acids." Journal of Food Protection 79, no. 12 (December 1, 2016): 2184–89. http://dx.doi.org/10.4315/0362-028x.jfp-16-156.
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ABSTRACT We investigated the synergistic effects of lysozyme combined with organic acids to inhibit the growth of Listeria monocytogenes. The antilisterial effects of the combination of lysozyme and acetic acid, citric acid, lactic acid, malic acid, or succinic acid were evaluated using the checkerboard method and time-kill assay. The MIC was 25,000 mg/liter for lysozyme, 625 mg/liter for acetic acid, and 1,250 mg/liter for the other acids. The MBC was 10,000 mg/liter for all of the tested organic acids. The combination of lysozyme and each organic acid showed synergistic effects via the checkerboard method; however, the time-kill assay showed synergistic effects for only three combinations of 1,250 mg/liter lysozyme with succinic acid (312 and 625 mg/liter) or malic acid (625 mg/liter). The results of this study indicate that the combination of lysozyme and malic acid or succinic acid can be effectively used as a food preservative to control L. monocytogenes.
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Tissier, Adeline, Martine Denis, Philippe Hartemann, and Benoît Gassilloud. "Development of a Rapid and Sensitive Method Combining a Cellulose Ester Microfilter and a Real-Time Quantitative PCR Assay To Detect Campylobacter jejuni and Campylobacter coli in 20 Liters of Drinking Water or Low-Turbidity Waters." Applied and Environmental Microbiology 78, no. 3 (December 2, 2011): 839–45. http://dx.doi.org/10.1128/aem.06754-11.
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ABSTRACTInvestigations ofCampylobacter jejuniandCampylobacter coliin samples of drinking water suspected of being at the origin of an outbreak very often lead to negative results. One of the reasons for this failure is the small volume of water typically used for detecting these pathogens (10 to 1,000 ml). The efficiencies of three microfilters and different elution procedures were determined using real-time quantitative PCR to propose a procedure allowing detection ofCampylobacterin 20 liters of drinking water or low-turbidity water samples. The results showed that more than 80% of the bacteria inoculated in 1 liter of drinking water were retained on each microfilter. An elution with a solution containing 3% beef extract, 0.05 M glycine at pH 9, combined with direct extraction of the bacterial genomes retained on the cellulose ester microfilter, allowed recovery of 87.3% (±22% [standard deviation]) ofCampylobacterper 1 liter of tap water. Recoveries obtained from 20-liter volumes of tap water spiked with aC. colistrain were 69.5% (±10.3%) and 78.5% (±15.1%) for 91 CFU and 36 CFU, respectively. Finally, tests performed on eight samples of 20 liters of groundwater collected from an alluvial well used for the production of drinking water revealed the presence ofC. jejuniandC. coligenomes, whereas no bacteria were detected with the normative culture method in volumes ranging from 10 to 1,000 ml. In the absence of available epidemiological data and information on bacterial viability, these last results indicate only that the water resource is not protected from contamination byCampylobacter.
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Makmur, Makmur, and Harli A. Karim. "PENGARUH BERBAGAI DOSIS POC HASIL FERMENTASI BIOGAS TERHADAP PERTUMBUHAN BIBIT TANAMAN KOPI ARABIKA (Coffea arabica (L.) Lini S 795)." Agro Bali: Agricultural Journal 3, no. 2 (December 24, 2020): 220–28. http://dx.doi.org/10.37637/ab.v3i2.565.
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Masalah yang dihadapi dalam pengembangan tanaman kopi adalah masalah pembibitan yang berkwalitas dan pemupukan di tingkat petani. Hal ini mendorong dilakukan penelitian pupuk organik cair. Penelitian ini bertujuan untuk menganalisis pengaruh aplikasi berbagai dosis pupuk organi cair terhadap Pertumbuhan bibit tanaman kopi. Penelitian ini menggunakan Rancangan Acak Kelompok (RAK), yang terdiri dari enam perlakuan pemberian pupuk organik cair (POC), yaitu 50 ml pupuk organik cair per liter air, 100 ml pupuk organik cair per liter air,150 ml pupuk organik cair per liter air, 200 ml pupuk organik cair per liter air, 250 ml pupuk organic cair per liter air dan 300 ml pupuk organik cair per liter air. Setiap perlakuan diulang 5 kali sehingga terdapat 30 unit percobaan. Hasil penelitian menunjukkan bahwa parameter tinggi tanaman dan jumlah daun berpengaruh sangat nyata pada taraf uji Duncan 0,05 dan 0,01 dan memberikan rata-rata hasil tertinggi pada perlakun 200 ml per liter air dengan nilai 39,6 cm terhadap tinggi tanaman, dan perlakuan 50 ml perliter air dengan nilai 39,8 helai terhadap jumlah daun pada pertumbuhan bibit tanaman kopi. Parameter diameter batang pada perlakuan 50 ml per liter air memberikan hasi tertinggi dengan nilai 3,96 mm bibit tanaman kopi.
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Santos, P., J. J. Nunez, and R. M. Davis. "Influence of Gibberellic Acid on Carrot Growth and Severity of Alternaria Leaf Blight." Plant Disease 84, no. 5 (May 2000): 555–58. http://dx.doi.org/10.1094/pdis.2000.84.5.555.
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Applications of gibberellic acid (GA) to carrot foliage consistently reduced the percentage of leaf area affected by Alternaria dauci compared with nontreated plants. The degree of leaf blight reduction with two applications of GA was similar to that achieved with four applications of the fungicide iprodione. At the rates examined (GA at 2.5 to 250 mg/liter), foliage dry weights were generally increased by GA. Although root weight was significantly reduced by rates of 250 mg/liter, applications of lower rates (40 mg/liter or less) reduced leaf blight severity without affecting root quality. Applications of GA usually resulted in plants with longer leaves, wider petioles, and a more upright growth habit. In one trial, leaf length and petiole diameter increased linearly with increasing rates (20, 30, and 40 mg/liter). When applied twice at 30 mg/liter, GA did not affect cuticle, epidermal, or leaf thickness. In general, the initial timing of two applications of 20 to 40 mg/liter (4, 6, or 8 weeks after plant emergence) did not influence the effects of GA. However, in one trial, there was a greater incidence of core separation from the root cortex when 40 mg/liter was applied initially at 4 weeks. GA at 30 mg/liter slightly but significantly decreased inner root color in one of two trials.
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Liu, Jialin, Yaying Li, Zihui Zhang, Wenhua Luo, Lan Cao, and Huai Liu. "Low Concentration of Quercetin Reduces the Lethal and Sublethal Effects of Imidacloprid on Apis cerana (Hymenoptera: Apidae)." Journal of Economic Entomology 114, no. 3 (March 26, 2021): 1053–64. http://dx.doi.org/10.1093/jee/toab043.
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Abstract Large-scale use of systemic pesticides has been considered a potential factor for pollinator population decline. Phytochemicals, e.g., quercetin, have been demonstrated to increase the pesticide tolerance of Apis mellifera Linnaeus (Hymenoptera: Apidae), which is helpful to develop strategies to reduce the pesticides hazards to pollinators. In this study, we hypothesized phytochemicals could reduce the detrimental effects of imidacloprid on Apis cerana Fabricius. The lethal and sublethal effects of imidacloprid on A. cerana workers were investigated. The results showed that A. cerana workers chronically exposed to 100 μg/liter imidacloprid had a significantly shorter longevity by 10.81 d compared with control. Acute exposure to imidacloprid at 100 μg/liter impaired the sucrose responsiveness and memory retention of the workers, and 20 μg/liter reduced the sucrose responsiveness. The treatment with 37.8 mg/liter quercetin for 24 h could increase the longevity of A. cerana workers when chronically exposed to 100 μg/liter imidacloprid, and 75.6 mg/liter quercetin feeding treatment alleviated the impairment of sucrose responsiveness. However, workers treated with 151.2 mg/liter and 75.6 mg/liter quercetin had a significantly shorter longevity compared to that of bees chronically exposed to 100 μg/liter imidacloprid without quercetin treatment. Our results suggested that quercetin treatment could produce a biphasic influence on the lethal effects of imidacloprid on A. cerana. Quercetin at 37.8 mg/liter and 75.6 mg/liter in the diet before pesticide exposure was able to reduce the lethal and sublethal effects of imidacloprid, respectively, providing potential strategies to reduce the pesticides hazards to native honey bees (A. cerana).
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Kousik, C. S., and A. P. Keinath. "First Report of Insensitivity to Cyazofamid Among Isolates of Phytophthora capsici from the Southeastern United States." Plant Disease 92, no. 6 (June 2008): 979. http://dx.doi.org/10.1094/pdis-92-6-0979a.
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Phytophthora capsici is rapidly becoming an important limiting factor in vegetable production in the southeastern United States, particularly on cucurbits as fruit rots. One of the strategies used to manage diseases caused by P. capsici is the regular application of fungicides. Recently the new fungicide cyazofamid (trade name Ranman, FRAC Group 21, FMC Corporation, EPA Reg. No. 71512-3-279) was registered for management of P. capsici on cucurbits. Cyazofamid has been reported to be very effective against P. capsici on peppers (1). In a recent evaluation, we observed that cyazofamid was not very effective on fruit rot of watermelon in a field artificially infested with P. capsici (3). Hence, we evaluated our collection of isolates for sensitivity to cyazofamid. We confirmed our isolates as P. capsici based on morphology of colonies and sporangia and amplification of internal transcribed spacer regions using specific PCR primers (4). Mycelial growth of 28 isolates from the southeastern United States including North (NC) and South Carolina (SC), Georgia (GA), and Florida (FL) was evaluated on Ranman amended (0, 25, 100, 310, 518, and 1,000 mg/liter of the active ingredient cyazofamid) V8 juice agar using similar techniques as described before (2). The EC50 (50% effective concentration) values ranged from 3.8 to 535 mg/liter. Thirteen isolates (8 GA, 3 SC, 1 NC, and 1 FL) had EC50 >100 mg/liter. Similar results were obtained when technical grade cyazofamid was used. The same 28 isolates were evaluated on media amended with technical grade cyazofamid (0, 1, 10, and 100 mg/liter) and 100 mg/liter of salicylhydroxaymic acid, which was added to inhibit the alternative oxidase enzyme. The EC50 values ranged from <1 to >100 mg/liter. Six isolates (5 GA and 1 NC) had EC50 >100 mg/liter. Three isolates, one sensitive and two insensitive, were used to inoculate cucumber (Cucumis sativus) fruits treated with commercial Ranman at 0, 10, 100, 300, and 1,000 mg/liter of cyazofamid plus the surfactant Silwett L-77 (0.52 ml/liter). Mycelial plugs (7-mm diameter) were placed on nonwounded fruits. Fruits were kept under high humidity at 25 ± 1°C in an incubator for 3 days. Two measurements of each lesion at right angles were averaged to get the lesion diameter. The EC50 value for lesion diameter on fruits varied from 13 mg/liter for the sensitive isolate to >233 mg/liter for the insensitive isolates. EC50 values for diameter of the lesion with sporulation ranged from 3 to 107 mg/liter. Relative lesion diameters of the insensitive isolates at 100 mg/liter treatment compared with nonsprayed check were 70 to 93%, and at 300 mg/liter, it was 38 to 80%. Similarly in another experiment, watermelon (Citrullus lanatus var. lanatus) fruits were sprayed with a recommended field rate of Ranman (284 mg of cyazofamid/liter) plus Silwett L-77 (0.52 ml/liter) till runoff and inoculated with four isolates. The relative lesion diameter for insensitive isolates on Ranman treated watermelon fruits were 76 to 100% of nonsprayed fruits. To our knowledge, these insensitive isolates were collected from fields that were never sprayed with Ranman. Because of the existence of cyazofamid insensitive P. capsici isolates, it should be rotated with fungicides from other chemical classes to prevent extensive selection of insensitive isolates. References: (1) K. L. Ivors et al. Plant Dis. Manage. Rep. 1:V088, 2007. (2) A. P. Keinath. Plant Dis. 91:743, 2007. (3) C. S. Kousik and R. Hassell. Plant Dis. Manage. Rep. 1:V010, 2007. (4) J. B. Ristaino et al. Appl. Environ. Microbiol. 64:948, 1998.
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Keinath, Anthony P. "Sensitivity of Populations of Phytophthora capsici from South Carolina to Mefenoxam, Dimethomorph, Zoxamide, and Cymoxanil." Plant Disease 91, no. 6 (June 2007): 743–48. http://dx.doi.org/10.1094/pdis-91-6-0743.
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In summer and fall 2003, Phytophthora blight and crown rot, caused by Phytophthora capsici, was found in three fields each of summer squash and pepper on three farms in two counties in South Carolina. Although this disease had been confirmed previously in the state, five of these outbreaks were in fields thought to be free of P. capsici. The objectives of this study were to determine whether isolates of P. capsici in South Carolina were sensitive to mefenoxam and to determine baseline sensitivities to dimethomorph, zoxamide, and cymoxanil, fungicides recently registered to control Phytophthora blight. Of 120 isolates tested for sensitivity to mefenoxam at 100 mg/liter, 8 isolates were resistant (relative colony diameter [RCD] > 90% of nonamended control), 60 isolates were sensitive (RCD < 30%), and 52 isolates were intermediately sensitive. Only sensitive isolates were found in two fields in which no mefenoxam-containing fungicides had ever been used. Intermediately sensitive or resistant isolates were found in the four fields in which mefenoxam had been applied previously. In all, 15 to 61 isolates were tested for sensitivity to dimethomorph, zoxamide, and cymoxanil. The concentrations at which RCD, percent cyst germination, and relative zoospore production were reduced to 50% (EC50 values) for mycelial growth were 0.19 ± 0.02 (± standard deviation) mg/liter for dimethomorph, 0.50 ± 0.50 mg/liter for zoxamide, and mostly >50 mg/liter for cymoxanil. EC50 values for zoospore cyst germination were 0.07 ± 0.02 mg/liter for dimethomorph and >50 mg/liter for cymoxanil. EC50 values for zoospore production were 0.63 ± 0.42 mg/liter for dimethomorph, 0.47 ± 0.51 mg/liter for zoxamide, and <50 mg/liter for cymoxanil. Sensitivity values obtained in this South Carolina study can be used as a comparative baseline to monitor shifts in sensitivity to the fungicides mefenoxam, dimethomorph, zoxamide, and cymoxanil in populations of P. capsici.
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Xin, Fengxue, Yi-Rui Wu, and Jianzhong He. "Simultaneous Fermentation of Glucose and Xylose to Butanol by Clostridium sp. Strain BOH3." Applied and Environmental Microbiology 80, no. 15 (May 23, 2014): 4771–78. http://dx.doi.org/10.1128/aem.00337-14.
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ABSTRACTCellulose and hemicellulose constitute the major components in sustainable feedstocks which could be used as substrates for biofuel generation. However, following hydrolysis to monomer sugars, the solventogenicClostridiumwill preferentially consume glucose due to transcriptional repression of xylose utilization genes. This is one of the major barriers in optimizing lignocellulosic hydrolysates that produce butanol. Unlike studies on existing bacteria, this study demonstrates that newly reportedClostridiumsp. strain BOH3 is capable of fermenting 60 g/liter of xylose to 14.9 g/liter butanol, which is similar to the 14.5 g/liter butanol produced from 60 g/liter of glucose. More importantly, strain BOH3 consumes glucose and xylose simultaneously, which is shown by its capability for generating 11.7 g/liter butanol from a horticultural waste cellulosic hydrolysate containing 39.8 g/liter glucose and 20.5 g/liter xylose, as well as producing 11.9 g/liter butanol from another horticultural waste hemicellulosic hydrolysate containing 58.3 g/liter xylose and 5.9 g/liter glucose. The high-xylose-utilization capability of strain BOH3 is attributed to its high xylose-isomerase (0.97 U/mg protein) and xylulokinase (1.16 U/mg protein) activities compared to the low-xylose-utilizing solventogenic strains, such asClostridiumsp. strain G117. Interestingly, strain BOH3 was also found to produce riboflavin at 110.5 mg/liter from xylose and 76.8 mg/liter from glucose during the fermentation process. In summary,Clostridiumsp. strain BOH3 is an attractive candidate for application in efficiently converting lignocellulosic hydrolysates to biofuels and other value-added products, such as riboflavin.
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CARVAJAL, MAGDA, ADOLFO BOLAÑOS, FRANCISCO ROJO, and IGNACIO MÉNDEZ. "Aflatoxin M1 in Pasteurized and Ultrapasteurized Milk with Different Fat Content in Mexico." Journal of Food Protection 66, no. 10 (October 1, 2003): 1885–92. http://dx.doi.org/10.4315/0362-028x-66.10.1885.
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High per capita milk consumption in Mexico indicated a strong need for documentation of aflatoxin M1 (AFM1) levels in milk. A survey of 580, 2-liter samples (n = 290), was conducted to quantify AFM1 using high-performance liquid chromatography, considering two maximum tolerance levels (0.05 and 0.5 μg/liter). We relate aflatoxin levels in the seven most consumed brands from different regions, with two processes (pasteurized and ultrapasteurized), different expiration dates, and different fat content: whole fat (28, 30, and 33 g), half-skimmed (10, 16, and 20 g), light (1, 2, and 4 g), and with vegetable oil. Pasteurization and ultrapasteurization did not diminish AFM1 contamination present at levels of 0 to 8.35 μg/liter in 40% of the milk samples at concentrations ≥0.05 μg/liter and in 10% of the samples at ≥0.5 μg/liter. Statistically significant relationships were AFM1 contamination with brand (P = 0.002 at the ≥0.05 μg/liter level and P = 0.034 at the ≥0.5 μg/liter level) and higher AFM1 levels with mild or warm seasons of the year (P = 0.0003). Samples with greater fat content had slightly more probability (P = 0.067) of being contaminated by AFM1 at the ≥0.5 μg/liter level. The milk with the lowest contamination of AFM1 was a brand imported as powder and rehydrated in Mexico.
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Hassan, Ismael Ahmad. "The Effect of Planting Distance and Spraying with Different Concentrations of (Micronate15) on Vegetative Growth and Yield Traits of Pea Plant (Pisum Sativum L.)." Kurdistan Journal of Applied Research 3, no. 2 (November 13, 2018): 13–19. http://dx.doi.org/10.24017/science.2018.3.3.
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The aim of this study was to find the effect of planting distances and spraying with different concentrations of leaf fertilizer with micronate15 on some vegetative growth traits and yield of pea variety Green Canada in non-heated greenhouses, by using three planting distance (factor A) which includes: A1:20, A2: 30, and A3:40 cm and four spray concentrations as foliar application (factor B) which includes: B0: zero, B1: 0.5, b2: 1.5 and b3: 2.5 liter of water). According to the results of this study the highest plant (124.82cm), number of branches (4.58), fresh weight,(95.94 g) and the total yield (142.41 g)were observed in the distance of planting (30 cm), while the highest value of the pod length was observed from the distance planting in 40 cm which is 8.39 cm. The concentration of 1.5 mL / liter of micronate15 gave the highest values of branches 4.53 branches, fresh weight 97.47 g, number of pods 36.73 pods, number of seeds 8.55 oats, length of the pod 8.83 cm and the total yield 150.78 g. The highest values of the number of branches 5.14 branch, fresh weight 105.72 g, the number of seeds 8.90 seed and the total yield 159.78 g were observed from the interaction between the planting distance of 30 cm and 1.5 mL / liter of nutrient micronate15. Also, the interaction between 20 cm distance and foliar application with 2.5 mL l of micronate15 gave the highest value in the number of leaves which is 53.36.
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WEISSINGER, W. R., K. H. McWATTERS, and L. R. BEUCHAT. "Evaluation of Volatile Chemical Treatments for Lethality to Salmonella on Alfalfa Seeds and Sprouts." Journal of Food Protection 64, no. 4 (April 1, 2001): 442–50. http://dx.doi.org/10.4315/0362-028x-64.4.442.
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A study was done to evaluate natural volatile compounds for their ability to kill Salmonella on alfalfa seeds and sprouts. Acetic acid, allyl isothiocyanate (AIT), trans-anethole, carvacrol, cinnamic aldehyde, eugenol, linalool, methyl jasmonate, and thymol were examined for inhibitory and lethal activity against Salmonella by exposing inoculated alfalfa seeds to compounds (1,000 mg/liter of air) for 1, 3, and 7 h at 60°C. Only acetic acid, cinnamic aldehyde, and thymol caused significant reductions in Salmonella populations (>3 log10 CFU/g) compared with the control (1.9 log10 CFU/g) after treatment for 7 h. Treatment of seeds at 50°C for 12 h with acetic acid (100 and 300 mg/liter of air) and thymol or cinnamic aldehyde (600 mg/liter of air) significantly reduced Salmonella populations on seeds (>1.7 log10 CFU/g) without affecting germination percentage. Treatment of seeds at 50°C with AIT (100 and 300 mg/liter of air) and cinnamic aldehyde or thymol (200 mg/liter of air) did not significantly reduce populations compared with the control. Seed germination percentage was largely unaffected by treatment with gaseous acetic acid, AIT, cinnamic aldehyde, or thymol for up to 12 h at 50°C. The number of Salmonella on seeds treated at 70°C for 80 min with acetic acid (100 and 300 mg/liter of air), AIT (100 mg/liter of air), and cinnamic aldehyde and thymol (600 mg/liter of air) at water activity (aw) 0.66 was not significantly different than the number inactivated on seeds at aw 0.49. Acetic acid at 200 and 500 mg/liter of air reduced an initial population of 7.50 log10 CFU/g of alfalfa sprouts by 2.33 and 5.72 log10 CFU/g, respectively, within 4 days at 10°C, whereas AIT at 200 and 500 mg/liter of air reduced populations to undetectable levels; however, both treatments caused deterioration in sensory quality. Treatment of sprouts with 1 or 2 mg of AIT per liter of air adversely affected sensory quality but did not reduce Salmonella populations after 11 days of exposure at 10°C.
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ZORRAQUINO, M. A., M. ROCA, N. FERNANDEZ, M. P. MOLINA, and R. ALTHAUS. "Heat Inactivation of β-Lactam Antibiotics in Milk." Journal of Food Protection 71, no. 6 (June 1, 2008): 1193–98. http://dx.doi.org/10.4315/0362-028x-71.6.1193.
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The presence of residues of antimicrobial substances in milk is one of the main concerns of the milk industry, as it poses a risk of toxicity to public health, and can seriously influence the technological properties of milk and dairy products. Moreover, the information available on the thermostability characteristics of these residues, particularly regarding the heat treatments used in control laboratories and the dairy industry, is very scarce. The aim of the study was, therefore, to analyze the effect of different heat treatments (40°C for 10 min, 60°C for 30 min, 83°C for 10 min, 120°C for 20 min, and 140°C for 10 s) on milk samples fortified with three concentrations of nine β-lactam antibiotics (penicillin G: 3, 6, and 12 μg/liter; ampicillin: 4, 8, and 16 μg/liter; amoxicillin: 4, 8, and 16 μg/liter; cloxacillin: 60, 120, and 240 μg/liter; cefoperazone: 55, 110, and 220 μg/liter; cefquinome: 100, 200, and 400 μg/liter; cefuroxime: 65, 130, and 260 μg/liter; cephalexin: 80, 160, and 220 μg/liter; and cephalonium: 15, 30, and 60 μg/liter). The method used was a bioassay based on the inhibition of Geobacillus stearothermophilus var. calidolactis. The results showed that heating milk samples at 40°C for 10 min hardly produced any heat inactivation at all, while the treatment at 83°C for 10 min caused a 20% loss in penicillin G, 27% in cephalexin, and 35% in cefuroxime. Of the three dairy industry heat treatments studied in this work, low pasteurization (60°C for 30 min) and treatment at 140°C for 10 s only caused a small loss of antimicrobial activity, whereas classic sterilization (120°C for 20 min) showed a high level of heat inactivation of over 65% for penicillins and 90% for cephalosporins.
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GOULAS, ANTONIOS E., KYRIAKOS A. RIGANAKOS, DIETER A. E. EHLERMANN, PANAGIOTIS G. DEMERTZIS, and MICHAEL G. KONTOMINAS. "Effect of High-Dose Electron Beam Irradiation on the Migration of DOA and ATBC Plasticizers from Food-Grade PVC and PVDC/PVC Films, Respectively, into Olive Oil." Journal of Food Protection 61, no. 6 (June 1, 1998): 720–24. http://dx.doi.org/10.4315/0362-028x-61.6.720.
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The effect of high-dose irradiation on the migration of dioctyl adipate (DOA) and acetyl tributyl citrate (ATBC) plasticizers from food-grade poly(vinyl chloride) (PVC) and poly(vinylidene chloride/vinyl chloride) (PVDC/PVC) copolymer (Saran) films, respectively, into olive oil was studied. The results showed a significantly higher amount of DOA migrated into olive oil from irradiated versus nonirradiated samples. This difference was more noticeable in oil samples collected during initial periods of contad. The amount of DOA migrating into olive oil was lower for samples irradiated at a dose of 20 kGy in comparison with samples irradiated at adose of 50 kGy. At a sampling time of 1 h the amount of DOA that migrated into olive oil was 93.9 mg/liter, 141.5 mg/liter, and 183.4 mg/liter for nonirradiated samples, 20-kGy irradiated samples, and 50-kGy irradiated samples, respectively. After 288 hr (12 days) of oil-film contad the respective amounts were 390.8 mg/liter, 409.2 mg/liter, and 430.1 mg/liter. There were no statistically significad differences in migrating amount of ATBC between nonirradiated samples and samples irradiated at a dose of 20 kGy, while in samples irradiated at a dose of 50 kGy the migration of ATBC was increased. After 1 h of oil-film contad no detectable amounts of ATBC had migrated. After 288 h of contad the amounts of ATBC that migrated into olive oil were 3.59 mg/liter, 3.56 mg/liter, and 4.12 mg/liter for nonirradiated samples, 20-kGy irradiated samples, and 50-kGy irradiated samples, respectively. It is suggested that plasticized PVC should not be used in direct contact with high-fat foodstuffs with or without irradiation treatment.
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PARK, CHUNG-MYEON, YEN-CON HUNG, CHYI-SHEN LIN, and ROBERT E. BRACKETT. "Efficacy of Electrolyzed Water in Inactivating Salmonella Enteritidis and Listeria monocytogenes on Shell Eggs." Journal of Food Protection 68, no. 5 (May 1, 2005): 986–90. http://dx.doi.org/10.4315/0362-028x-68.5.986.
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The efficacy of acidic electrolyzed (EO) water produced at three levels of total available chlorine (16, 41, and 77 mg/liter) and chlorinated water with 45 and 200 mg/liter of residual chlorine was investigated for inactivating Salmonella Enteritidis and Listeria monocytogenes on shell eggs. An increasing reduction in Listeria population was observed with increasing chlorine concentration from 16 to 77 mg/liter and treatment time from 1 to 5 min, resulting in a maximal reduction of 3.70 log CFU per shell egg compared with a deionized water wash for 5 min. There was no significant difference in antibacterial activities against Salmonella and Listeria at the same treatment time between 45 mg/liter of chlorinated water and 14-A acidic EO water treatment (P ≥ 0.05). Chlorinated water (200 mg/liter) wash for 3 and 5 min was the most effective treatment; it reduced mean populations of Listeria and Salmonella on inoculated eggs by 4.89 and 3.83 log CFU/shell egg, respectively. However, reductions (log CFU/shell egg) of Listeria (4.39) and Salmonella (3.66) by 1-min alkaline EO water treatment followed by another 1 min of 14-A acidic EO water (41 mg/liter chlorine) treatment had a similar reduction to the 1-min 200 mg/liter chlorinated water treatment for Listeria (4.01) and Salmonella (3.81). This study demonstrated that a combination of alkaline and acidic EO water wash is equivalent to 200 mg/liter of chlorinated water wash for reducing populations of Salmonella Enteritidis and L. monocytogenes on shell eggs.
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Yoshida, Akihito, Taku Nishimura, Hideo Kawaguchi, Masayuki Inui, and Hideaki Yukawa. "Enhanced Hydrogen Production from Formic Acid by Formate Hydrogen Lyase-Overexpressing Escherichia coli Strains." Applied and Environmental Microbiology 71, no. 11 (November 2005): 6762–68. http://dx.doi.org/10.1128/aem.71.11.6762-6768.2005.
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ABSTRACT Genetic recombination of Escherichia coli in conjunction with process manipulation was employed to elevate the efficiency of hydrogen production in the resultant strain SR13 2 orders of magnitude above that of conventional methods. The formate hydrogen lyase (FHL)-overexpressing strain SR13 was constructed by combining FHL repressor (hycA) inactivation with FHL activator (fhlA) overexpression. Transcription of large-subunit formate dehydrogenase, fdhF, and large-subunit hydrogenase, hycE, in strain SR13 increased 6.5- and 7.0-fold, respectively, compared to the wild-type strain. On its own, this genetic modification effectively resulted in a 2.8-fold increase in hydrogen productivity of SR13 compared to the wild-type strain. Further enhancement of productivity was attained by using a novel method involving the induction of the FHL complex with high-cell-density filling of a reactor under anaerobic conditions. Continuous hydrogen production was achieved by maintaining the reactor concentration of the substrate (free formic acid) under 25 mM. An initial productivity of 23.6 g hydrogen h−1 liter−1 (300 liters h−1 liter−1 at 37°C) was achieved using strain SR13 at a cell density of 93 g (dry weight) cells/liter. The hydrogen productivity reported in this work has great potential for practical application.
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Atim, Margaret, Fen Beed, Geoffrey Tusiime, Leena Tripathi, and Piet van Asten. "High Potassium, Calcium, and Nitrogen Application Reduce Susceptibility to Banana Xanthomonas Wilt Caused by Xanthomonas campestris pv. musacearum." Plant Disease 97, no. 1 (January 2013): 123–30. http://dx.doi.org/10.1094/pdis-07-12-0646-re.
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The effect of exogenous applications of potassium (K), calcium (Ca), and nitrogen (N) on the susceptibility of four banana cultivars to Banana Xanthomonas wilt (BXW) was studied. Murashige and Skoog (MS) medium with normal concentrations of K at 783 mg/liter, Ca at 121 mg/liter, and N at 841 mg/liter was modified to contain various concentrations of K, Ca, and N. Each nutrient was varied singly, each with three replicate experiments. The concentrations were K at 78, 157, 391, 783, 1,565, and 3,913 mg/liter; Ca at 12, 24, 60, 121, 241, and 603 mg/liter; and N at 84, 168, 420, 841, and 1,682 mg/liter. Plantlets were generated in vitro on normal MS medium and later exposed to the nutrient concentrations for a total of 8 weeks. Thereafter, they were artificially inoculated with Xanthomonas campestris pv. musacearum using an insulin syringe. In each nutrient, plantlets exposed to higher nutrient concentrations significantly (P < 0.0001) accumulated more nutrient in their tissues compared with those exposed to lesser nutrient concentrations. Wilt incidences were significantly reduced, and incubation periods (time from inoculation to appearance of first disease symptoms) increased, with increasing nutrient application. The study lays a background for in vivo studies aimed at management of BXW using nutrients, such as fertilizer application.
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Chang, Chung-Jan. "Pathogenicity of Aster Yellows Phytoplasma and Spiroplasma citri on Periwinkle." Phytopathology® 88, no. 12 (December 1998): 1347–50. http://dx.doi.org/10.1094/phyto.1998.88.12.1347.
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Using Murashige and Skoog (MS) as a basal medium, the effects of varying levels and combinations of plant growth regulators required for shoot tip and root proliferation in healthy and aster yellows phytoplasma (AYP)- and Spiroplasma citri-infected periwinkle (Catharanthus roseus) shoots were studied. Number of shoots and fresh and dry mass of healthy and AYP-infected shoots increased when benzyladenine (BA) concentrations were increased from 0.5 to 4 mg/liter. The maximum number of shoots for both healthy and AYP-infected plants was obtained when grown in MS medium supplemented with BA at 4 mg/liter and indole-3-acetic acid (IAA) at 0.5 mg/liter. S. citri-infected shoots proliferated the most when grown in MS medium containing BA at 2 mg/liter and IAA at 0.5 mg/liter. The best medium for root production in healthy periwinkle shoots contained α-naphthaleneacetic acid (NAA) at 0.5 mg/liter, whereas the best medium for AYP-infected shoots contained indole-3-butyric acid (IBA) at 2.5 mg/liter, both in combination with kinetin at 0.1 mg/liter. S. citri-infected shoots had the best root growth when grown in medium supplemented with IBA at 5.0 mg/liter and kinetin at 0.1 mg/liter. The concentration of cytokinin and auxin needed for maximum shoot proliferation differed between AYP- and S. citri-infected shoot tips, strongly indicating that the two mollicutes may cause different changes in endogenous cytokinin and auxin levels. The concentrations of NAA and IBA needed for root growth of S. citri-infected shoots were two- to fivefold higher than the concentrations needed for healthy and AYP-infected shoots, clearly demonstrating that S. citri infection caused a shortage of auxins that resulted in retardation of secondary root growth. Chlorophyll content was markedly reduced in periwinkles infected with AYP or S. citri compared with chlorophyll in healthy periwinkles. AYP caused a decrease in carotenoid in leaves 6 weeks after graft-inoculation, but carotenoid content was unchanged in S. citri-infected leaves throughout the test period. Anthocyanin content in periwinkles infected with AYP decreased significantly by 4 weeks postinoculation, whereas anthocyanin content in periwinkles infected with S. citri increased. Anthocyanin content in leaf tissues, however, was reduced as a result of AYP and S. citri infection. Pigment changes induced by AYP and S. citri, whether similar or different compared with those of healthy periwinkle shoots, provide important information for interpreting pathogenesis when linked with plant growth regulators.
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Ali, Mahrus, Fauziatun Nisak, and Yeni Ika Pratiwi. "PEMANFAATAN LIMBAH CAIR IKAN TUNA TERHADAP PERTUMBUHAN TANAMAN PAKCHOY DENGAN WICK SYSTEM HYDROPONIK." Agro Bali: Agricultural Journal 3, no. 2 (December 24, 2020): 186–93. http://dx.doi.org/10.37637/ab.v3i2.616.
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Limbah ikan di Indonesia belum dimanfaatkan secara maksimal. Kurangnya pengetahuan masyarakat tentang pemanfaatan limbah ikan dan belum adanya penerapan teknologi dalam pengelolaan limbah ikan menjadi kendala dalam pemanfaatan limbah ikan. Penelitian ini bertujuan untuk mengetahui pengaruh pemberian berbagai konsentrasi pupuk organik limbah ikan tuna terhadap pertumbuhan dan hasil tanaman pakchoy. Penelitian dilaksanakan di Kebun Percobaan Fakultas Pertanian Universitas Merdeka Surabaya. Metode Penelitian ini menggunakan Rancangan Acak Kelompok (RAK) dengan pola menggunakan1 faktor yaitu Konsentrasi Pupuk Organik Cair Limbah Ikan Tuna (P) terdiri dari 5 level perlakuan, antara lain: P0 = 0 ml POC per liter air; P1 = 5 ml POC per liter air; P2 = 10 ml POC per liter air; P3 = 15 ml POC per liter air; P4 = 20 ml POC per liter air dan P5 = 25 ml POC per liter air.Percobaan ini diulang 3 kali dengan tiap-tiap perlakuan terdapat 5 tanaman sampel, sehingga diperoleh 75 perlakuan.Adapun parameter yang diamati antara lain :Panjang tanaman (cm),Jumlah daun,Panjang akar, Berat segar tanaman (gram). Berdasarkan hasil penelitian, maka dapat disimpulkan sebagai berikut : 1). Terdapat pengaruh signifikan dari konsentrasi POC limbah ikan tuna terhadap peningkatan pertumbuhan tanaman pakchoi pada variabel yang diteliti, meliputi : jumlah daun, panjang tanaman, panjang akar, berat basah per tanaman pada masa pertumbuhan tanaman pakchoi. 2).Nilai tertinggi dicapai oleh perlakuan P5 yaitu konsentrasi sebesar 25 ml POC limbah ikan tuna per liter air pada semua parameter pengamatan; namun secara statistik nilai optimal dicapai oleh perlakuan P4 (20 ml POC urine sapi per liter air) karena berbeda tidak nyata dengan perlakuan P5 pada semua variable yang diteliti, seperti jumlah daun, panjang akar, berat basah per tanaman karena dianggap lebih efektif dan efisien.
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KESKIN, YAŞAR, RUHTAN BAŞKAYA, SEHER KARSLI, TÜRKAN YURDUN, and OĞUZ ÖZYARAL. "Detection of Aflatoxin M1 in Human Breast Milk and Raw Cow's Milk in Istanbul, Turkey." Journal of Food Protection 72, no. 4 (April 1, 2009): 885–89. http://dx.doi.org/10.4315/0362-028x-72.4.885.
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This survey was undertaken to determine the extent of aflatoxin M1 (AFM1) contamination in human breast milk and raw cow's milk in Istanbul, Turkey. Samples of human and raw cow's milk were collected randomly and analyzed for AFM1 using an enzyme-linked immunosorbent assay and high-performance liquid chromatography with fluorescence detection in which the samples were cleaned up with immunoaffinity columns. In this study, AFM1 was detected in 8 (13.1%) of 61 human breast milk samples examined (mean ± SD level, 5.68 ± 0.62 ng/liter; range, 5.10 to 6.90 ng/liter) and 20 (33.3%) of 60 raw cow's milk samples examined (range, 5.40 to 300.20 ng/liter). Five (8.3%) of the positive raw cow's milk samples had AFM1 levels (153.52 ± 100.60 ng/liter; range, 61.20 to 300.20 ng/liter) that were higher than the maximum tolerance limit (0.05 ppb) stipulated by regulations in Turkey and some other countries.
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BAL'A, M. FARID A., and DOUGLAS L. MARSHALL. "Use of Double-Gradient Plates To Study Combined Effects of Salt, pH, Monolaurin, and Temperature on Listeria monocytogenes†." Journal of Food Protection 59, no. 6 (June 1, 1996): 601–7. http://dx.doi.org/10.4315/0362-028x-59.6.601.
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This study evaluated the combined effects of pH, NaCl, incubation temperature, and sublethal concentrations of monolaurin on the survival of Listeria monocytogenes using the double-gradient diffusion technique. L. monocytogenes tolerance to NaCl was greatest (>78 g/liter) at neutral pH (6.8 to 7.2) and increased in the pH range 7.0 to 5.4 as the incubation temperature was lowered. Monolaurin at 2 μg/ml lowered the salt tolerance of L. monocytogenes to 60 g/liter independently of pH. At 4 μg of monolaurin per ml, salt tolerance was reduced to approximately 40 g/liter with no growth occurring at pH 6.0 to 5.4 and 25 g of NaCl per liter. At 8 μg of monolaurin per ml, only a subpopulation of the initial inoculum tolerated 25 g of NaCl per liter at neutral pH (6.5 to 7.5). Monolaurin reduced the tolerance of L. monocytogenes to NaCl and low pH.
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JASSON, VICKY, ANDREJA RAJKOVIC, LEEN BAERT, JOHAN DEBEVERE, and MIEKE UYTTENDAELE. "Comparison of Enrichment Conditions for Rapid Detection of Low Numbers of Sublethally Injured Escherichia coli O157in Food." Journal of Food Protection 72, no. 9 (September 1, 2009): 1862–68. http://dx.doi.org/10.4315/0362-028x-72.9.1862.
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A comparative study of lag phases and growth rates of healthy, stressed, and sublethally injured Escherichia coli O157 cells in 10 enrichment broths was performed. The evaluation of enrichment protocols was validated by different end point detection methods (two PCR and two combined capture-plate methods). Tryptic soy broth b [TSB (b)] provided the fastest growth (μmax = 1.00 ± 0.06 h−1) but failed to recover oxidative-stressed E. coli O157. TSB (a), TSB–yeast extract medium, TSB supplemented with 8 mg/liter novobiocin plus 16 mg/liter vancomycin (TSB+), buffered peptone water (BPW), and BPW supplemented with 8 mg/liter vancomycin (BPW+V) enabled resuscitation of E. coli O157 cells independent from precultural conditions. Modified TSB plus 10 mg/liter novobiocin (mTSB+N), EC medium, EC reduced bile salts medium (ECred), TSB (b), and TSB supplemented with 8 mg/liter novobiocin plus 16 mg/liter vancomycin plus 2 mg/liter rifampin plus 1 mg/liter K-Telluriet plus 1.5 g/liter bile salts no. 3 (TSB++) all failed to recover E. coli O157 cells for at least one type of stress. The use of TSB (a), TSB+, BPW, and BPW+V was compared with that of mTSB+N (International Organization for Standardization reference broth) for reliable detection of low numbers of healthy, stressed, and sublethally injured E. coli O157 (approximately 10 CFU/10 g) from foods (sprouted seeds, fermented sausage, raw milk, and raw ground beef). When low numbers of healthy cells were inoculated, BPW, BPW+V, TSB, TSB+, and mTSB+N enabled growth until detectable numbers within 6 h of enrichment at 41.5°C. Results showed that mTSB+N failed to recover to detectable numbers E. coli O157 cells sublethally injured by freeze and food stresses, in contrast to what was obtained with BPW and BPW+V. This study highlights that using mTSB+N for recovery of E. coli O157 from foods may yield false-negative results.
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Ben-Yephet, Y., M. Reuven, A. Zviebil, Y. Szmulewich, I. Lavkovits, T. Markovits, S. Soriano, and B. Bar-Yosef. "Effect of Nutrition on Deformation Disease in Gypsophila paniculata Mother Plants." Phytopathology® 96, no. 7 (July 2006): 771–76. http://dx.doi.org/10.1094/phyto-96-0771.
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Deformation disease of Gypsophila paniculata mother plants reduces cutting yields as much as 50% but does not kill the mother plants. In preliminary experiments, fertigation of G. paniculata mother plants with a 20:20:20 compound fertilizer (N, P, K, plus microelements) at an N concentration of 720 mg/liter reduced the expression of deformation disease compared with the conventional N concentration of 360 mg/liter. The current study determined which component of the compound fertilizer reduced the disease. Experiments were carried out in 10-liter buckets packed with naturally infested 0- to 8-mm black tuff (Scoria = crushed volcanic stones). Irrigation was applied once a day at 0.5 liter per bucket with the nutrient under test being added at 1.0 liter per bucket via the water once a week. Treatments included: (i) four levels of 20:20:20 fertilizer; (ii) four levels of each of N, P, K, and Fe-Zn-Mn mixture (ME) corresponding to their concentrations in the compound fertilizer; (iii) different N sources (20:20:20, (NH4)2SO4, KNO3, NH4NO3, urea); and (iv) three pHs of the irrigation water at each of three NO3 and NH4 application levels. Increasing the 20:20:20 fertilizer concentration reduced the disease level from 82 to 96% with N at 180 mg/liter to 6 to 10% with N at 720 mg/liter. When either P, K, or ME was the sole variable, increasing concentrations had no significant effect on the disease, but elevating a mixed source nitrogen concentration from 0 to 180, 360, and 720 mg/liter (as 50% urea, 40% NH4NO3, and 10% KNO3) significantly reduced deformation similar to that observed with increasing concentrations of the 20:20:20 fertilizer. mong tested N sources, NH4 was the most effective in reducing the disease (almost to zero at an N concentration of 360 g/liter). Low disease incidence (0 to 10%) was always associated with effluent pH of 6 or lower. Irrigating with acidified water pH 5.5) in the presence of N, as NH4 at 180 mg/liter, additionally reduced disease from 56% under tap water (pH 7.8) rrigation to 11%. Similar acidification in the presence of NO - 3 N at 180 mg/liter was ineffective in reducing the disease, but ater basification in the presence of NO - 3 N reduced disease incidence from 93 to 38% 90 days after planting. The N, P, K, Fe, and Zn concentrations in gypsophila cuttings were similar under the three tested levels of NH4, NO3, and 20:20:20, whereas the concentration of Mn increased with increasing N. The Mn concentration in cuttings was inversely correlated with disease and is probably an important factor to understanding the physiological background of the deformation disease.
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WATANABE, MITSURU, and HISASHI SHIMIZU. "Detection of Patulin in Apple Juices Marketed in the Tohoku District, Japan." Journal of Food Protection 68, no. 3 (March 1, 2005): 610–12. http://dx.doi.org/10.4315/0362-028x-68.3.610.
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Patulin is a mycotoxin mainly produced by Penicillium and Aspergillus. We investigated the incidence of patulin contamination in 179 samples of apple juice and 9 samples of mixed juice (containing apple juice concentrate as an ingredient) commercially available in the Tohoku district of Japan. Patulin was detected in 3 of 143 samples containing domestic fruits and in 6 of 45 samples containing imported products and products produced in Japan using imported apple juice concentrate. Patulin analyses were carried out using high-pressure liquid chromatography with a detection limit of 4 μg/liter. The patulin content of contaminated domestic samples (three samples with concentrations ranging from 6 to 10 μg/liter), imported samples (one sample with a concentration of 15 μg/liter), and domestic samples produced containing imported concentrate (five samples with concentrations ranging from 6 to 9 μg/liter) was lower than the maximum limit of 50 μg/liter currently adopted by many countries, including Japan.
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Keinath, Anthony P., and Thomas A. Zitter. "Resistance to Benomyl and Thiophanate-methyl in Didymella bryoniae from South Carolina and New York." Plant Disease 82, no. 5 (May 1998): 479–84. http://dx.doi.org/10.1094/pdis.1998.82.5.479.
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An initial collection of 7 isolates of Didymella bryoniae were grown on media amended with 0, 1, 3.2, 10, 31.2, or 100 mg benomyl per liter. Four isolates grew at all five concentrations of benomyl, but the other 3 isolates did not grow at concentrations > 1 mg/liter. Colony diameter of the four resistant isolates was reduced by 50% at 33.1 mg benomyl per liter, relative to growth on nonamended medium. Of 394 isolates tested, 182 isolates were resistant to benomyl; 178 of these resistant isolates were from South Carolina, 1 was from New York, and 3 were from Florida. Of 196 isolates grown on medium amended with 100 mg/liter thiophanate-methyl, 95 were sensitive and 101 were resistant. Essentially all isolates that were resistant to benomyl were resistant to thiophanate-methyl. In greenhouse tests, watermelon plants were sprayed with 0, 1.5, 15, 150, or 1,500 mg benomyl per liter and inoculated 1 day later with either a sensitive or a resistant isolate of D. bryoniae. Relative percent leaf area diseased was greater (P≤0.02) for the resistant isolate than for the sensitive isolate at ≥1.5 mg benomyl per liter. The occurrence of pathogenic, benzimidazole-resistant D. bryoniae in the eastern United States may reduce the effectiveness of benzimidazole fungicides for gummy stem blight management.
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Miller, T. C., and W. D. Gubler. "Sensitivity of California Isolates of Uncinula necator to Trifloxystrobin and Spiroxamine, and Update on Triadimefon Sensitivity." Plant Disease 88, no. 11 (November 2004): 1205–12. http://dx.doi.org/10.1094/pdis.2004.88.11.1205.
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Sensitivities of Uncinula necator to spiroxamine and trifloxystrobin were established by assay of 36 and 35 isolates, respectively, recovered from California grape vineyards in 2002 and increased as single-spore lines for laboratory testing. Twenty-nine single-spore isolates also were evaluated for levels of sensitivity to the fungicide triadimefon to determine if there had been a reversion to sensitivity following the development of resistance in 1986. Although triadimefon use was limited after 1992, other demethylation inhibitor (DMI) fungicides (fenarimol and myclobutanil) were used extensively in California vineyards. For spiroxamine, the sample mean value of the median effective concentration (EC50 value) was 365 μg/liter (95% confidence interval [CI] from 251 to 531 μg/liter) and values were distributed log-normally. The corresponding mean for trifloxystrobin was 12.8 μg/liter bounded by 8.9 to 18.5 μg/liter for the 95% CI. State-wide, the triadimefon mean EC50 was 8.8 mg/liter, bounded by a 5.3 to 14.5 mg/liter 95% CI, and those values were significantly higher than those obtained in the last assay 12 years earlier. Significant differences in sensitivity of U. necator to triadimefon were detected at a regional scale by comparison of mean EC50 values of frequency distributions representative of regions within California, although the relations between those regions were different from the prior survey.
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VALENZUELA, ANTONIO SÁNCHEZ, NABIL BENOMAR, HIKMATE ABRIOUEL, MAGDALENA MARTÍNEZ CAÑAMERO, ROSARIO LUCAS LÓPEZ, and ANTONIO GÁLVEZ. "Biocide and Copper Tolerance in Enterococci from Different Sources." Journal of Food Protection 76, no. 10 (October 1, 2013): 1806–9. http://dx.doi.org/10.4315/0362-028x.jfp-13-124.
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Antimicrobial resistance in enterococci is a matter of concern. A collection of 272 strains (including 107 Enterococcus faecalis and 165 Enterococcus faecium strains) isolated from meat and dairy products, seafood, vegetable foods, wildflowers, animal feces (ewe, goat, horse, mule), and hospitals were tested for sensitivity to biocides of different classes (quaternary ammonium compounds, a bisphenol, and a biguanide) and copper sulfate. Most isolates were inhibited at 25 mg of benzalkonium chloride or cetrimide per liter or at 2.5 mg of hexadecylpyridinium chloride per liter. Few isolates had MICs higher than 25 mg/liter for benzalkonium chloride (2.2%), cetrimide (0.74%), or hexadecylpyridinium chloride (0.37%), although they were all inhibited at 250 mg/liter. The population response to triclosan was very homogeneous, and most isolates (98.16%) were inhibited at 250 mg of triclosan per liter. Chlorhexidine showed the greatest variability, with MICs in a range from 2.5 to 2,500 mg/liter. Remarkably, 74.57% of isolates from clinical samples required 2,500 mg of chlorhexidine per liter for inhibition, compared to much-lower concentrations required for most isolates from other sources. Enterococci were inhibited by copper sulfate in a concentration range from 4 to 16 mM, with no bimodal distribution. However, most isolates required 12 mM (41.91%) or 16 mM (47.43%) for inhibition. The highest percentages of isolates requiring 16 mM CuSO4 were from vegetable foods, seafood, and wildflowers. The results from the present study suggest intermediate levels of copper tolerance and a low incidence of biocide tolerance in the enterococci investigated, except for chlorhexidine in clinical isolates.
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Sebayuana, Kadek, Tjokorda Gde Tirta Nindhia, I. Wayan Surata, Tjokorda Sari Nindhia, Shailendra Kumar Shukla, and Samir Kumar Khanal. "Performance of 500 Liter Stainless Steel Portable Biogas Anaerobic Digester with Agitator Designed for the Tropical Developing Country." Key Engineering Materials 877 (February 2021): 160–65. http://dx.doi.org/10.4028/www.scientific.net/kem.877.160.
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This document it is established that 2 types of biogas anaerobic digester that usually found in developing country. First type is fixed dome type of anaerobic digester and secondly is floating drum biogas anaerobic digester. Both of this type have draw back that the anaerobic process is not completed with agitation process that yield low rate of biogas production. Other serious problem is the release of slurry cannot optimal. Some of the slurry will still remain stay in the anaerobic digester especially scum. To drain and cleaning the fixed dome or floating drum biogas anaerobic digester is mandatory to be done regularly that consume time and cost. The fixed dome types as well as floating drum type are usually not portable which cause no possibility to relocate in the new site. It is the purpose of this work to introduce portable biogas anaerobic digester that suitable for developing country with volume of digester around 500 liter of slurry. The requirement of agitator is facilitated, and the anaerobic digester is possible to be operated in batch system or continuous system. The material that is used for anaerobic digester is stainless steel 304 with tungsten inert gas welding technology that is used for the manufacturing. With this design the anaerobic digester are easy to be maintenance. The batch system can keep producing biogas until 52 day with total production of biogas around 3320 liters. The continuous system was conducted by releasing for about 5 liters slurry from the outlet and after that filled with new slurry with stirring with agitator was conducted for about 10 minutes for 3 times in a day (morning, noon, and evening). The result for continuous system is a linear biogas production with rate biogas production is around 51.7 liter/day (1550 liter/30days).
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Yang, P. Y., and S. Y. Nagano. "A Potential Treatment Alternative for Swine Wastewater in the Tropics." Water Science and Technology 17, no. 4-5 (April 1, 1985): 819–31. http://dx.doi.org/10.2166/wst.1985.0182.
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Development of a low-cost and effective swine waste management system in the tropics is the main objective of this study. Because of the apppropriate temperature environment and abundance of sunlight, an integration of an anaerobic digestion and an algal biomass process was selected and investigated. A pilot, plant integrating a 20 m3 anaerobic digester with sludge recycling and a 120 m3 algal-biomass raceway were installed and evaluated. Maximum gas production rate of 1.527 liter/liter/day (69% methane content) can be achieved by a TVS loading rate of 4.23 gram/liter/day. A sludge production rate of 0.82-2.62 g TS/liter is obtained from a TVS loading rate of 0.76-4.23 g TVS/liter/day. Critical SRT for maximum gas production rate is 2.67. For the algal biomass raceway, a loading rate of 0.097 g SCOD/liter/day or 0.017 g NH4-N/liter/day would achieve SCOD and NH4-N removal efficiencies of 94.44% and 98.42%, respectively. Combining the previous analysis of energy input and land requirement for an algal biomass raceway and mass balance of energy production and utilization, integrating the energy production (anaerobic digestion) and energy utilization (dehydration of digested sludge and power requirement of raceway) provides a great potential for a swine wastewater treatment in the tropics.
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Villena, Isabelle, Dominique Aubert, Philippe Gomis, Hubert Ferté, Jean-Christophe Inglard, Hélène Denis-Bisiaux, Julie-Muriel Dondon, Eric Pisano, Naïma Ortis, and Jean-Michel Pinon. "Evaluation of a Strategy for Toxoplasma gondii Oocyst Detection in Water." Applied and Environmental Microbiology 70, no. 7 (July 2004): 4035–39. http://dx.doi.org/10.1128/aem.70.7.4035-4039.2004.
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ABSTRACT Several recent outbreaks of toxoplasmosis were related to drinking water. We propose a strategy for Toxoplasma oocyst detection as part of an approach to detecting multiple waterborne parasites, including Giardia and Cryptosporidium spp., by the U.S. Environmental Protection Agency method with the same sample. Water samples are filtered to recover Toxoplasma oocysts and purified on a sucrose density gradient. Detection is based on PCR and mouse inoculation (bioassay) to determine the presence and infectivity of recovered oocysts. In an experimental seeding assay with 100 liters of deionized water, a parasite density of 1 oocyst/liter was successfully detected by PCR in 60% of cases and a density of 10 oocysts/liter was detected in 100% of cases. The sensitivity of the PCR assay varied from less than 10 to more than 1000 oocysts/liter, depending on the sample source. PCR was always more sensitive than mouse inoculation. This detection strategy was then applied to 139 environmental water samples collected over a 20-month period. Fifty-three samples contained PCR inhibitors, which were overcome in 39 cases by bovine serum albumin addition. Among 125 interpretable samples, we detected Toxoplasma DNA in 10 cases (8%). None of the samples were positive by mouse inoculation. This strategy efficiently detects Toxoplasma oocysts in water and may be suitable as a public health sentinel method.
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Wang, Yixiao, Alireza Akhavan, Sheau-Fang Hwang, and Stephen E. Strelkov. "Decreased Sensitivity of Leptosphaeria maculans to Pyraclostrobin in Alberta, Canada." Plant Disease 104, no. 9 (September 2020): 2462–68. http://dx.doi.org/10.1094/pdis-11-19-2461-re.
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Leptosphaeria maculans, the causal agent of blackleg of canola (Brassica napus), can be managed with pyraclostrobin and other strobilurin fungicides. Their frequent application, however, poses a risk for the development of insensitivity in fungal populations. A collection of L. maculans single-spore isolates recovered from infected canola stubble in Alberta, Canada, in 2016 was evaluated for its pyraclostrobin sensitivity. In conventional growth plate assays, the concentration of pyraclostrobin required to inhibit fungal growth by 50% (EC50) was determined to be 0.28 mg/liter in a subset of 38 isolates. This EC50 was four times greater than the mean EC50 (0.07 mg/liter) of baseline isolates collected in 2011. Two hundred sixty-three isolates were screened further with two discriminatory doses of 0.28 and 3.5 mg/liter of pyraclostrobin, resulting in growth inhibition values ranging from 16 to 82% and 41 to 100%, respectively. In microtiter plate assays with the same isolates, the mean EC50 was determined to be 0.0049 mg/liter, almost 3.3 times greater than the mean EC50 (0.0015 mg/liter) of the baseline isolates. The sensitivity of the isolates was also evaluated in microtiter plate assays with discriminatory doses of 0.006 and 0.075 mg/liter of pyraclostrobin, resulting in inhibition values ranging from 20 to 88% and 49 to 100%, respectively. This is the first report of isolates of L. maculans with increased insensitivity to pyraclostrobin in Canada, suggesting the need for improved fungicide stewardship.
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DEVECİ, ORGUN, and EMEL SEZGİN. "Changes in Concentration of Aflatoxin M1 during Manufacture and Storage of Skim Milk Powder." Journal of Food Protection 69, no. 3 (March 1, 2006): 682–85. http://dx.doi.org/10.4315/0362-028x-69.3.682.
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In this study, skim milk powder was produced from cow's milk contaminated artificially with aflatoxin M1 (AFM1) at two different levels, 1.5 and 3.5 μg/liter (ppb), and the effects of process stages on the AFM1 contents were investigated. Pasteurization, concentration, and spray drying caused losses of about 16, 40, and 68%, respectively, in AFM1 content of the milk contaminated with 1.5 μg/liter AFM1, and losses of 12, 35, and 59%, respectively, in the milk contaminated with 3.5 μg/liter AFM1. These losses were found to be statisticially significant at the level of P < 0.01. After 3- and 6-month storage periods, AFM1 content of the skim milk powder produced from milk with 1.5 μg/liter AFM1 decreased by 2 and 5%, respectively, whereas these rates were 2 and 4%, respectively, for the skim milk powders made from milk with 3.5 μg/liter AFM1 (after adjustment for sample weight). Changes in AFM1 content of milk powder samples were found statistically insignificant (P > 0.05 and P > 0.01) for 3- and 6-month storage periods.
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WARBURTON, D. W., J. W. AUSTIN, B. H. HARRISON, and G. SANDERS. "Survival and Recovery of Escherichia coli O157: H7 in Inoculated Bottled Water." Journal of Food Protection 61, no. 8 (August 1, 1998): 948–52. http://dx.doi.org/10.4315/0362-028x-61.8.948.
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A methodology used to isolate Escherichia coli O157:H7 from water and survival of this pathogen in inoculated water is described. The methodology used in the isolation of E. coli O157:H7 included the use of selective plating on Sorbitol MacConkey agar (supplemented with potassium tellurite [2.5 mg/liter], cefixime [0.05 mg/liter], and cefsulodin [10 mg/liter], and modified hemorrhagic colitis agar (also supplemented with potassium tellurite [2.5 mg/liter] and cefsulodin [10 mg/liter]). There were no significant differences (P < 0.05) between the recoveries of E. coli O157:H7 on these two selective media. Direct plating on these selective agars was used to determine the length of time that E. coli O157:H7 was able to grow, remain viable, and be resistant to the selective agents. E. coli O157:H7 survived in inoculated water for up to >300 days, depending on the type of water. Observation by scanning electron microscopy indicated that E. coli O157:H7 cells attached to, and multiplied on, the container walls.
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YURDUN, TÜRKAN, GÜLDEN ZEHRA OMURTAG, and ÖMER ERSOY. "Incidence of Patulin in Apple Juices Marketed in Turkey." Journal of Food Protection 64, no. 11 (November 1, 2001): 1851–53. http://dx.doi.org/10.4315/0362-028x-64.11.1851.
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The purpose of this study was to investigate the patulin contamination of apple juices consumed by the Turkish population. Patulin was detected using high-performance liquid chromatography (HPLC) with a UV detector at 280 nm, and the identification of patulin was further confirmed by thin-layer chromatography (TLC). Using HPLC, the recoveries were 79.9 ± 6.7% and 83.7 ± 4.6%, and the coefficients of variation were 8.4 and 5.5% for apple juices spiked with the known amounts of patulin (60 and 120 μg/liter, respectively). The minimum patulin level detected was 5 ng in a standard solution and 5 μg/liter in apple juices. The TLC method was used only to confirm patulin levels higher than 20 μg/liter (100 ng/spot) in apple juices. The total number of samples was 45. Patulin was present in detectable levels in 60% of apple juices at concentrations ranging from 19.1 to 732.8 μg/liter. Forty-four percent of the apple juice samples had patulin contamination levels higher than 50 μg/liter, which is the allowable upper limit in Turkey.
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GALVANO, FABIO, VITTORIO GALOFARO, ANNA DE ANGELIS, MARCO GALVANO, MATTEO BOGNANNO, and GIACOMO GALVANO. "Survey of the Occurrence of Aflatoxin M1 in Dairy Products Marketed in Italy." Journal of Food Protection 61, no. 6 (June 1, 1998): 738–41. http://dx.doi.org/10.4315/0362-028x-61.6.738.
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During 1995, 159 samples of milk, 97 samples of dry milk for infant formula, and 114 samples of yogurt were randomly collected in supermarkets and drug stores in four large Italian cities and checked for aflatoxin M1 (AFM1) by immunoaffinity column extraction and HPLC. AFM1 was detected in 136 (86%) of the milk samples (in amounts ranging from <1 ng/liter to 108.5 ng/liter; mean level: 10.19 ng/liter), in 81 (84%) of the dry milk samples (in amounts ranging from < 1 ng/kg to 101.3 ng/kg; mean level: 21.77 ng/kg), and in 91 (80%) of the yogurt samples (in amounts ranging from <1 ng/liter to 496.5 ng/liter; mean level: 18.08 ng/liter). Altogether, only two samples of milk, two samples of yogurt, and one sample of dry milk had levels of AFM1 exceeding the Swiss legal limits, which are the most restrictive in the world. AFM1 contamination levels in milk and yogurt samples collected in the period of November to April were ca. four times as high as those in samples collected in the period of May to October. It is concluded that during 1995, despite the widespread occurrence of AFM1, the mean contamination levels in dairy products sold in Italy were not a serious human health hazard.
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VAEREWIJCK, M. J. M., K. SABBE, J. BARÉ, H. P. SPENGLER, H. W. FAVOREEL, and K. HOUF. "Assessment of the Efficacy of Benzalkonium Chloride and Sodium Hypochlorite against Acanthamoeba polyphaga and Tetrahymena spp." Journal of Food Protection 75, no. 3 (March 1, 2012): 541–46. http://dx.doi.org/10.4315/0362-028x.jfp-11-359.
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The efficacy of benzalkonium chloride and sodium hypochlorite against Acanthamoeba polyphaga and two Tetrahymena spp. was determined based on the European Standard EN 1276:2009 suspension test. Trophozoite viability was assessed by determination of the membrane integrity using flow cytometry as a fast screening technique. Bovine serum albumin was added to simulate clean (0.3 g/liter) and dirty (3 g/liter) conditions. Benzalkonium chloride caused cell lysis at concentrations above 50 mg/liter under clean and dirty conditions. A concentration of 50 mg of free chlorine per liter had a strong biocidal effect on acanthamoebae and tetrahymenae after 15 min under clean and dirty conditions. Our results suggest that benzalkonium chloride and sodium hypochlorite were effective against the three microorganisms at concentrations commonly applied in the food industry.
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Copes, W. E. "Dose Curves of Disinfestants Applied to Plant Production Surfaces to Control Botrytis cinerea." Plant Disease 88, no. 5 (May 2004): 509–15. http://dx.doi.org/10.1094/pdis.2004.88.5.509.
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Lethal dose curves were calculated using probit analysis for six disinfestants (chlorazene hydrosol, hydrogen dioxide, hydrogen peroxide, iodine, quaternary ammonium chloride, sodium hypochlorite) when applied on seven substrates (galvanized metal, stainless steel, polyethylene ground fabric, polyethylene pot plastic, pressure-treated pine, exterior latex-painted pine, raw pine) that had been inoculated with Botrytis cinerea conidia. Mortality was determined by percentage of ungerminated versus germinated conidia that had been rubbed off of a substrate onto half-strength potato dextrose agar (hPDA) 16 to 24 h previously. Based on overlapping confidence limits (95% CL) of the lethal doses resulting in 90 and 50% mortality (LD90 and LD50, respectively) and significance of slopes, differences occurred between substrates with all six disinfestants. LD90 values ranged from 0.21 to 4.54 g a.i./liter for chlorazene hydrosol, 4.99 to 40.3 g a.i./liter for hydrogen dioxide, 63.0 to 233.1 g a.i./liter for hydrogen peroxide, 0.42 to 2.45 g a.i./liter for iodine, 0.64 to 6.46 g a.i./liter for quaternary ammonium chloride, and 0.87 to 6.84 g a.i./liter for sodium hypochlorite. For hydrogen dioxide, quaternary ammonium chloride, and sodium hypochlorite, a binomial lethal dose (LDb) was calculated by plating the inverted inoculated substrates on hPDA, then recording the presence or absence of B. cinerea mycelial growth over 7 days. Lethal doses resulting in the absence of mycelial growth (LDb100) were equal to or greater than the LD90 values for most disinfestants and substrates. Results demonstrate for the six disinfestants that dose should be selected based on the substrate being disinfested of B. cinerea conidia.
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Bowness, Robyne, Bruce D. Gossen, Kan-Fa Chang, Rubella Goswani, Christian J. Willenborg, Michael Holtz, and Stephen E. Strelkov. "Sensitivity of Mycosphaerella pinodes to Pyraclostrobin Fungicide." Plant Disease 100, no. 1 (January 2016): 192–99. http://dx.doi.org/10.1094/pdis-03-15-0350-re.
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Mycosphaerella blight, caused by Mycosphaerella pinodes, is a destructive disease of field pea that is managed using foliar fungicides. Strobilurin fungicides have been used in western Canada for disease management since 2003. To assess the baseline sensitivities of M. pinodes isolates to the strobilurin fungicide pyraclostrobin, the effective concentration to reduce mycelial growth by 50% (EC50) was determined for 70 isolates collected prior to 2003 from Alberta, Saskatchewan, North Dakota, and Washington State. Each of these isolates was sensitive to pyraclostrobin, with EC50 values ranging from 0.03 to 0.29 mg liter−1. The pyraclostrobin concentrations required to reduce conidia germination by 50% was lower, ranging from 0.008 to 0.041 mg liter−1. In all, 324 isolates collected in 2010 and 2011 were tested for high levels of insensitivity by examining mycelial growth using a discriminatory dose of 5 mg liter−1. Nineteen isolates were highly insensitive to pyraclostrobin, with EC50 values of 80 to 216 mg liter−1. Conidia of these isolates germinated when exposed to a discriminatory dose of 0.1 mg liter−1. Insensitive isolates infected field pea plants treated with pyraclostrobin but sensitive isolates did not. The identification of insensitive isolates indicates that insensitivity may be emerging in the pathogen population.
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McEGAN, R., T. J. FU, and K. WARRINER. "Concentration and Detection of Salmonella in Mung Bean Sprout Spent Irrigation Water by Use of Tangential Flow Filtration Coupled with an Amperometric Flowthrough Enzyme-Linked Immunosorbent Assay." Journal of Food Protection 72, no. 3 (March 1, 2009): 591–600. http://dx.doi.org/10.4315/0362-028x-72.3.591.
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The development of a culture-free method for Salmonella screening of spent irrigation water derived from sprouting mung bean beds is described. The system used tangential flow filtration (TFF) to nonspecifically concentrate cells from large (2- to 10-liter) sample volumes. The retentate (100 ml) from the TFF was then flowed over an anti-Salmonella antibody–modified cellulose acetate membrane. The captured Salmonella was detected by reacting with a secondary anti-Salmonella and goat anti-rabbit biotin labeled antibody, followed by avidin-tagged glucose oxidase. The hydrogen peroxide generated from the enzymic oxidation of glucose was amperometrically detected at an underlying platinum electrode. It was found that 10 liters of Salmonella suspensions of 2 log CFU/ml could be concentrated to 4 log CFU/ml with 60% recovery regardless of the flow rate (112 to 511 ml/min) or transmembrane pressure (0 to 20 lb/in2) applied. The solids content of spent irrigation water negatively affected the filtration rate of TFF. This was most evident in spent irrigation water collected in the initial 24 h of the sprouting period, where the solids content was high (4,170 mg/liter) compared with samples collected at 96 h (560 mg/liter). Trials were performed using mung bean beds inoculated with different Salmonella levels (1.3 to 3.3 log CFU/g). By using the optimized TFF and flowthrough immunoassay it was possible to detect Salmonella in spent irrigation water at levels of 2.43 log CFU/ml within 4 h. The integrated concentration and detection system will provide a useful tool for sprout producers to perform in-house pathogen screening of spent irrigation water.
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Zhong, Zhi-Ping, Ying Liu, Li-Li Miao, Fang Wang, Li-Min Chu, Jia-Li Wang, and Zhi-Pei Liu. "Prokaryotic Community Structure Driven by Salinity and Ionic Concentrations in Plateau Lakes of the Tibetan Plateau." Applied and Environmental Microbiology 82, no. 6 (January 8, 2016): 1846–58. http://dx.doi.org/10.1128/aem.03332-15.
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ABSTRACTThe prokaryotic community composition and diversity and the distribution patterns at various taxonomic levels across gradients of salinity and physiochemical properties in the surface waters of seven plateau lakes in the Qaidam Basin, Tibetan Plateau, were evaluated using Illumina MiSeq sequencing. These lakes included Lakes Keluke (salinity, <1 g/liter), Qing (salinity, 5.5 to 6.6 g/liter), Tuosu (salinity, 24 to 35 g/liter), Dasugan (salinity, 30 to 33 g/liter), Gahai (salinity, 92 to 96 g/liter), Xiaochaidan (salinity, 94 to 99 g/liter), and Gasikule (salinity, 317 to 344 g/liter). The communities were dominated byBacteriain lakes with salinities of <100 g/liter and byArchaeain Lake Gasikule. The clades At12OctB3 andSalinibacter, previously reported only in hypersaline environments, were found in a hyposaline lake (salinity, 5.5 to 6.6 g/liter) at an abundance of ∼1.0%, indicating their ecological plasticity. Salinity and the concentrations of the chemical ions whose concentrations covary with salinity (Mg2+, K+, Cl−, Na+, SO42−, and Ca2+) were found to be the primary environmental factors that directly or indirectly determined the composition and diversity at the level of individual clades as well as entire prokaryotic communities. The distribution patterns of two phyla, five classes, five orders, five families, and three genera were well predicted by salinity. The variation of the prokaryotic community structure also significantly correlated with the dissolved oxygen concentration, pH, the total nitrogen concentration, and the PO43−concentration. Such correlations varied depending on the taxonomic level, demonstrating the importance of comprehensive correlation analyses at various taxonomic levels in evaluating the effects of environmental variable factors on prokaryotic community structures. Our findings clarify the distribution patterns of the prokaryotic community composition in plateau lakes at the levels of individual clades as well as whole communities along gradients of salinity and ionic concentrations.
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Tanović, B., and M. Ivanović. "First Report of Occurrence of Benomyl Resistance in Botrytis cinerea Isolates on Raspberry in Serbia." Plant Disease 94, no. 4 (April 2010): 486. http://dx.doi.org/10.1094/pdis-94-4-0486c.
Full textAbstract:
Botrytis fruit rot, caused by Botrytis cinerea, is one of the major diseases limiting production of raspberries (Rubus idaeus) in Serbia. Yield losses in commercial fields can exceed 50%, especially during periods of rainy, wet weather before harvest. Development of resistance to fungicides with site-specific modes of action is a serious problem in the control of B. cinerea worldwide. To insure the longest possible useful life of a fungicide, an early detection of shifts of sensitivity in pathogen population is crucial (1). The goal of this study was to evaluate sensitivity of B. cinerea isolates from commercial raspberry fields in Serbia to several fungicides that are frequently used: vinclozolin, benomyl, pyrimethanil, and fenhexamid. Initial isolation was done from sporulating berries during harvest. Single-spore isolates were identified based on colony and conidial morphology and by PCR amplification of an expected 0.7-kbp DNA fragment using B. cinerea-specific primer pair C729+/729- (3). Sensitivity of 130 isolates from six localities (20 to 30 isolates per locality) was determined on potato dextrose agar (PDA) amended with fungicides at discriminatory concentrations (1 and 10 mg/liter). Fungicides were suspended in sterile distilled water and added to autoclaved media that had cooled to 50°C. Inverted mycelial plugs (10-mm diameter), which had been cut from the edge of 4-day-old colonies on PDA, were placed on fungicide amended media and incubated for 48 h at 20°C. Treatments were replicated four times and the experiment repeated once. Strain SAS 56, which is sensitive to benzimidazoles and dicarboximides, and strain SAS 405, which is resistant to these fungicide classes, originating from German Collection of Microorganisms and Cell Cultures, were used as standards in the experiment. Isolates that did not grow at 1 mg/liter were designated as sensitive, those that grew at 10 mg/liter were considered highly resistant, and those that grew at 1 mg/liter but not at 10 mg/liter were classified as weakly resistant to all fungicides tested. Values of EC50 for all highly resistant strains were determined in radial growth experiments on PDA supplemented with a range of concentrations (5,000, 2,500, 1,000, and 500 mg/liter) of benomyl or thiophanate-methyl, according to the method described by Leroux and Gredt (2). All tested isolates were sensitive to vinclozolin, pyrimethanil, and fenhexamid. Nine of 130 isolates were highly resistant to benomyl with EC50 values between 1,056 and 1,523 mg/liter. The reference strain SAS 56 had an EC50 value of 0.17 mg/liter, compared to an EC50 value for SAS 405 strain of 1,548 mg/liter. All benomyl resistant isolates were also resistant to thiophanate-methyl and EC50 values ranged from 2,328 to 7,699 mg/liter. To our knowledge, this is the first report of benomyl resistance in isolates of B. cinerea on raspberry in Serbia. References: (1) H. Ishii. Jarq 40:205, 2006. (2) P. Leroux and M. Gredt. Page 1 in: Laboratoire de Phytopharmacie, INRA, Versailles, 1972. (3) S. Rigotti et al. FEMS Microbiol. Lett. 209:169, 2002.
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ALBERTO, MARÍA R., MARTA E. FARÍAS, and MARÍA C. MANCA de NADRA. "Effect of Wine Phenolic Compounds on Lactobacillus hilgardii 5w Viability." Journal of Food Protection 65, no. 1 (January 1, 2002): 211–13. http://dx.doi.org/10.4315/0362-028x-65.1.211.
Full textAbstract:
After 6 days of Lactobacillus hilgardii 5w incubation at 4°C, the viable cell counts diminish 31.9, 45.6, and 89.0% when suspended in control wine (2,600 mg/liter gallic acid equivalents [GAE]), three-fold concentrated wine (6,150 mg/liter GAE), and six-fold concentrated wine (13,000 mg/liter GAE), respectively. At 20°C in the same conditions, the cell viabilities decrease 74.2, 80.5, and 100.0%, respectively. In decolorized wines, which result in tannin losses, the viable cell counts increase. There is a relationship between L. hilgardii 5w tannin binding and its viability loss.