Journal of Environmental Microbiology and Toxicology最新文献_第10页

Isolation and characterization of molybdenum-reducing and PEG-degrading Enterobacter cloacae strain KIK-14 in agricultural soil from Nigeria 尼日利亚农业土壤中还原钼和降解聚乙二醇的阴沟肠杆菌KIK-14的分离与鉴定

Journal of Environmental Microbiology and Toxicology Pub Date : 2017-07-31 DOI: 10.54987/jemat.v5i1.414

M. Shukor, M. Othman, K. I. Karamba, M. Halmi, M. F. Rahman, N. A. Yasid, S. Ahmad, H. Yakasai

{"title":"Isolation and characterization of molybdenum-reducing and PEG-degrading Enterobacter cloacae strain KIK-14 in agricultural soil from Nigeria","authors":"M. Shukor, M. Othman, K. I. Karamba, M. Halmi, M. F. Rahman, N. A. Yasid, S. Ahmad, H. Yakasai","doi":"10.54987/jemat.v5i1.414","DOIUrl":"https://doi.org/10.54987/jemat.v5i1.414","url":null,"abstract":"Today, numerous researches have demonstrated the cost-effectiveness of bioremediation to waste removal from agricultural and industrial sectors particularly at lower levels of the toxicants, where other physicochemical techniques are ineffective. Multiple toxicant remediation by a single microorganism is important for remediation of sites contaminated with numerous toxicants. In this work, a molybdenum-reducing bacterium was screened for its ability to use the xenobiotic polyethylene glycol (PEG) as the sole source of carbon for growth and as electron donor source for molybdate reduction. Biochemical analysis results in the tentative identification of the isolate as Enterobacter cloacae strain KIK-14. The use of PEGs as an electron donor in this bacterium did not support molybdenum-blue production, even though the bacterium grew well on PEGs 200, 300, 600 and 1000 independent of molybdate reduction. Reduction of molybdate to Mo-blue was optimal at pH between 6.0 and 6.3, the temperature between 25 and 37 oC, molybdate and phosphate concentrations between 15 and 20 mM and between 5.0 and 7.5 mM respectively. The best electron donor source supporting the reduction process was glucose. The Mo-blue absorption spectrum resembles reduced phosphomolybdate and is similar to that of the previous Mo-reducing bacterium. At 2 ppm of silver, mercury and copper, molybdenum reduction was inhibited by 41.5, 57.1 and 40.5%, respectively. The ability of this bacterium to detoxify mixed toxicants makes it an important tool for bioremediation.","PeriodicalId":393012,"journal":{"name":"Journal of Environmental Microbiology and Toxicology","volume":"02 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130642241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

A confidence interval comparison chart to assess the sensitivity of acetylcholinesterase from Hemibagrus nemurus as a source of enzyme for insecticides detection 用置信区间比较图评估半黑鼠乙酰胆碱酯酶作为杀虫剂检测酶源的敏感性

Journal of Environmental Microbiology and Toxicology Pub Date : 2017-07-31 DOI: 10.54987/jemat.v5i1.416

N.A.M. Asri, G. Begum, S. Ahmad, N. A. Yasid, M. Shukor

{"title":"A confidence interval comparison chart to assess the sensitivity of acetylcholinesterase from Hemibagrus nemurus as a source of enzyme for insecticides detection","authors":"N.A.M. Asri, G. Begum, S. Ahmad, N. A. Yasid, M. Shukor","doi":"10.54987/jemat.v5i1.416","DOIUrl":"https://doi.org/10.54987/jemat.v5i1.416","url":null,"abstract":"In this work, the potential of acetylcholinesterase (AChE) from Hemibagrus nemurus (Baung) as a sensitive tool to detect the presence of insecticides was assessed. The affinity partially purified fraction was utilized as a source of AChE for in vitro assay of the effect of insecticides on the AChE. The resultant IC50 values were then compared with published results. An IC50 confidence interval comparison chart coined Shukorâ€™s chart was utilized to compare the sensitivity of the AChE from H. nemurus to various other published results. In this chart, the IC50 confidence interval (95%) values for a particular insecticide is placed at one end of the chart and lined up with published values of IC50. Two lines are then made crossing the entire chart and represent the 95% confidence interval value for H. nemurus. Any confidence interval values for targeted insecticides from published results that do not touch these two lines are deemed significantly different (p<0.05), either more or less sensitive judging whether they fall below or above the two lines, respectively, whilst any confidence interval values that fall in or touch the two lines are deemed comparable in sensitivity.The results show that the AChE from H. nemurus is more sensitive to diazinonoxon and comparable in sensitivity compared to commercial and other local fish sources suggesting that the ACHE from H. nemurus can be a cheaper alternative for the current commercially and locally available AChEs. ","PeriodicalId":393012,"journal":{"name":"Journal of Environmental Microbiology and Toxicology","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121101594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Testing the normality of residuals on regression model for the growth of sludge microbes on PEG 600 用回归模型检验peg600污泥微生物生长的残差正态性

Journal of Environmental Microbiology and Toxicology Pub Date : 2015-07-27 DOI: 10.54987/jemat.v3i1.242

M. Halmi, M. S. Shukor, N. A. Masdor, N. A. Shamaan, M. Shukor

引用次数: 0

Evaluation of several mathematical models for fitting the growth of sludge microbes on PEG 600 几种拟合peg600污泥微生物生长的数学模型的评价

Journal of Environmental Microbiology and Toxicology Pub Date : 2015-07-27 DOI: 10.54987/jemat.v3i1.237

M. Halmi, M. S. Shukor, N. A. Masdor, N. A. Shamaan, M. Shukor

引用次数: 15

Test of randomness of residuals for the modified Gompertz model used in the fitting the growth of sludge microbes on PEG 600 用于拟合peg600上污泥微生物生长的修正Gompertz模型的残差随机性检验

Journal of Environmental Microbiology and Toxicology Pub Date : 2015-07-27 DOI: 10.54987/jemat.v3i1.240

M. Halmi, M. S. Shukor, N. A. Masdor, N. A. Shamaan, M. Shukor

引用次数: 6

Outlier analysis of the modified Gompertz model used in fitting the growth of sludge microbes on PEG 600 用于拟合peg600上污泥微生物生长的修正Gompertz模型的离群值分析

Journal of Environmental Microbiology and Toxicology Pub Date : 2015-07-27 DOI: 10.54987/jemat.v3i1.241

M. Halmi, M. S. Shukor, N. A. Masdor, N. A. Shamaan, M. Shukor

{"title":"Outlier analysis of the modified Gompertz model used in fitting the growth of sludge microbes on PEG 600","authors":"M. Halmi, M. S. Shukor, N. A. Masdor, N. A. Shamaan, M. Shukor","doi":"10.54987/jemat.v3i1.241","DOIUrl":"https://doi.org/10.54987/jemat.v3i1.241","url":null,"abstract":"Polyethylene glycols (PEGs) are employed in numerous sectors. PEGs are nephrotoxic and their biodegradation by microbes could be a potential tool for bioremediation. Numerous bacterial growth studies neglect primary modelling even though modelling exercises can reveal important parameters. Previously, we have utilized several growth models to model the growth of sludge microbes on PEG 600. We discovered that the modified Gompertz model via nonlinear regression utilizing the least square method was the best model to describe the growth curve. However, the use of statistical tests to choose the best model relies heavily on the residuals of the curve to be statistically robust. More often than not, the residuals must be tested for the presence of outliers (at 95 or 99% of confidence). In this work, the Grubbâ€™s test to detect the presence of outlier in the growth model was carried out. The test detected an outlier. This datum point will be removed in all future statistical tests such as normality, runs test, tests for homoscedasticity and presence of autocorrelation. In addition, remodeling of the data using the modified Gompertz model will be carried out.","PeriodicalId":393012,"journal":{"name":"Journal of Environmental Microbiology and Toxicology","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133045318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Test for the presence of autocorrelation in the modified Gompertz model used in the fitting the growth of sludge microbes on PEG 600 用于拟合peg600上污泥微生物生长的修正Gompertz模型中存在自相关的检验

Journal of Environmental Microbiology and Toxicology Pub Date : 2015-07-27 DOI: 10.54987/jemat.v3i1.238

M. Halmi, M. S. Shukor, N. A. Masdor, N. A. Shamaan, M. Y. Shukor

引用次数: 9

Test for the Presence of Autocorrelation in the Buchanan model used in the Fitting of the Growth of the Catechol-degrading Candida parapsilopsis 用于拟合儿茶酚降解假丝酵母拟合生长的Buchanan模型中存在自相关的检验

Journal of Environmental Microbiology and Toxicology Pub Date : 2014-12-30 DOI: 10.54987/jemat.v2i2.167

Shukor

{"title":"Test for the Presence of Autocorrelation in the Buchanan model used in the Fitting of the Growth of the Catechol-degrading Candida parapsilopsis","authors":"Shukor","doi":"10.54987/jemat.v2i2.167","DOIUrl":"https://doi.org/10.54987/jemat.v2i2.167","url":null,"abstract":"Catechol is a metabolic byproduct of phenol degradation by microbes. Its toxicity to human, mammals, insects and fishes has been long studied and its presence in the environment at toxic concentrations has been demonstrated. Fortunately there are microbes that could degrade catechol and can be used in bioremediation works. The growth of these microbes usually exhibit sigmoidal pattern due to the toxicity of the substrate. Previously, using the least square method in nonlinear regression, we report that the Buchanan three-phase model is the best model in fitting the growth of the yeast Candida parapsilopsis on this substrate. The ordinary least squares method relies heavily on several important assumptions such as residuals conformation to normal distribution, does not have outliers, is truly random, of equal variance (homoscedastic) and does not show autocorrelation. If all of these assumptions are satisfied, the test is said to be robust. In this work we perform statistical diagnosis test to test for the presence of autocorrelation as the growth model is time-dependent and many time-dependent curves shows evidence of autocorrelation. ","PeriodicalId":393012,"journal":{"name":"Journal of Environmental Microbiology and Toxicology","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115521996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 8

A Microplate Format for Characterizing the Growth of Molybdenum-reducing Bacteria 表征钼还原菌生长的微孔板格式

Journal of Environmental Microbiology and Toxicology Pub Date : 2014-12-14 DOI: 10.54987/jemat.v2i2.164

Shukor

{"title":"A Microplate Format for Characterizing the Growth of Molybdenum-reducing Bacteria","authors":"Shukor","doi":"10.54987/jemat.v2i2.164","DOIUrl":"https://doi.org/10.54987/jemat.v2i2.164","url":null,"abstract":"Molybdenum is toxic to ruminants and the process of spermatogenesis in catfish and mice. The bioremediation of heavy metals including molybdenum is being intensely studied. More efficient reducers are being isolated. An advantage of microbial molybdate reduction to molybdenum blue is the intense blue product absorbs wavelength strongly in the far red region whilst cells without the addition of molybdenum showed little absorption in this region. This means that no sample treatments such as centrifugation are needed and the readings can be taken straight away. In this work we developed a microplate or a microtiter plate assay for monitoring molybdenum blue production from a bacterium. The molybdenum blue produced when measured from a microplate gave about 2 times less absorbance intensity compared to measurement using a normal cuvette, but is adequate for characterization works as the absorbance obtained was 0.886 compared to 1.709 for measurement using cuvette. The development of microplate format for monitoring microbial reduction to molybdenum blue is simple to perform and would ensure works on the characterizations of novel molybdenum reducers can potentially be carried out in a few days instead of a few weeks.","PeriodicalId":393012,"journal":{"name":"Journal of Environmental Microbiology and Toxicology","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125939162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 44

Effect of Heavy Metals on Cyanide Biodegradation by Resting Cells of Serratia marcescens strain AQ07 重金属对粘质沙雷菌AQ07静息细胞降解氰化物的影响

Journal of Environmental Microbiology and Toxicology Pub Date : 2014-12-14 DOI: 10.54987/jemat.v2i2.192

K. K. Ibrahim

引用次数: 5