Tannery wastewater causes serious ecological and sanitary damage. Chemical analysis of water from Binlamdoune River of the medina of Fez was conducted and the results revealed the presence of toxic elements from tanne...Tannery wastewater causes serious ecological and sanitary damage. Chemical analysis of water from Binlamdoune River of the medina of Fez was conducted and the results revealed the presence of toxic elements from tanneries and other industrial activities, which strongly affected water quality. To determine the effectiveness of bioremediation for depollution, we studied the abundance and diversity of bacteria residing in these polluted environments. Conducting denaturing gradient gel electrophoresis （PCR-DGGE） of the 16S rDNA area using primers related to bacteria showed a bacterial community belonging to eubacterial groups, that is, Epsilonproteobacteria, Clostridia, Lactobacillales, Bacteroidetes, Gammaproteobacteria, and Alphaproteobacteria. In addition, cloning displayed the presence of clones belonging to the Firmicutes group. Moreover, scanning electron microscopy revealed a significant heterogeneity of microorganism forms and structures. These endogenous microbes could have a significant role in the purification of Binlamdoune River and Fez tannery wastewater.展开更多
Oil contaminated soil was collected from Huangpu River-Yangtze River estuary wetland, with the aim of isolating oil-degrading microorganisms and evaluating their ability to degrade diesel. Three bacterial strains were...Oil contaminated soil was collected from Huangpu River-Yangtze River estuary wetland, with the aim of isolating oil-degrading microorganisms and evaluating their ability to degrade diesel. Three bacterial strains were discovered and identified by sequencing their 16S rDNA genes, two were Pseudomonas and one was Alcaligcnes. The proper growth conditions of each bacterium were measured and presented for diesel biodegradation. Biodegradation assays revealed that the degradation rates of three bacterial strains were 42.5%, 14.6% and 15.9% in 7 d respectively. They all play an important role on the nalkanes within the range of C16-C25 components of diesel. The results indicated that the oil-degraders can adapt to degrade diesel. The bacterial strains can be used in wetland diesel pollution control.展开更多
Objective To measure the acute toxicity of halogenated benzenes to bacteria in natural waters and to study quantitative relationships between the structure and activity of chemicals. Methods The concentration values c...Objective To measure the acute toxicity of halogenated benzenes to bacteria in natural waters and to study quantitative relationships between the structure and activity of chemicals. Methods The concentration values causing 50% inhibition of bacteria growth （24h-IC50） were determined according to the bacterial growth inhibition test method. The energy of the lowest unoccupied molecular orbital and the net charge of carbon atom of 20 halogenated benzenes were calculated by the quantum chemical MOPAC program. Results The logl/IC50 values ranged from 4.79 for 2,4-dinitrochlorobenzene to 3.65 for chlorobenzene. A quantitative structure-activity relationship model was derived from the toxicity and structural parameters： logl/IC50 =-0.531（ELUMO）＋1.693（Qc）＋0.163（logP）＋3.375. This equation was found to fit well （r^2=0.860, s=0.106）, and the average percentage error was only 1.98%. Conclusion Halogenated benzenes and alkyl halogenated benzenes are non-polar narcotics, and have hydrophobicity-dependent toxicity. The halogenated phenols and anilines exhibit a higher toxic potency than their hydrophobicity, whereas 2,4-dinitrochlorobenzene is electrophile with the halogen acting as the leaving group.展开更多
The aim of the study was to analyse and identify microbial constituents in the water and sediment samples with comparison of the River to World Health Organisation (WHO, 2011) standard for drinking water and Federal M...The aim of the study was to analyse and identify microbial constituents in the water and sediment samples with comparison of the River to World Health Organisation (WHO, 2011) standard for drinking water and Federal Ministry of Environment (FME, 2006) and their public health implications with respect to water quality. The microbial assay of Otamiri River was investigated using Standard plate count. The result indicates that microbial constituents of Otamiri river obtained at five strategic gauge stations designated SSWS1 (Egbu), SSWS2 (Timber Market), SSWS3 (FUTO), DOWNSTREAM (Mbirichi) and CONTROL POINT with mean Total coliform Count of 3.0 × 102, 3.0 × 103, 4.1 × 103 and 1.0 × 103 cfu/100ml with control point value of 0.5 × 103 respectively. The mean Total Bacteria Count was 3.0 × 104, 2.1 × 103, 1.1 × 103 and 0.8 × 103 cfu/100ml respectively with control point value of 0.2 × 103 while the mean values for Total E. coli Count were 1.1 × 102, 3.0 × 102, 4 × 103 and 2.0 × 103 cfu/100ml with control point value of 0.2 × 103. The biochemical identification of some organisms in water was Escherichia coli, Vibro spp., Klebsiella spp., and Entrobacteria spp. The result of stream sediment samples indicates that the mean Total Bacterial Count was 3.5 × 104, 5.0 × 104, 6.5 × 104 and 2.0 × 104 cfu/g respectively with 1.5 × 102 as control point value and that of Total Coliform Count was 6.5 × 103, 2.0 × 103, 2.5 × 103 and 0.8 × 103 cfu/g respectively with control point value of 0.5 × 102. While for the Total E. coli Count, the values were 2.5 × 103, 1.0 × 103, 2.5 × 103 and 0.5 × 105 cfu/g respective with control as 0.5 × 102. Biochemical identification of some organisms in sediments includes: Escherichia coli, Vibro spp., Klebsiella spp., Entrobacteria spp. and Bacillus spp. The mean total bacterial count, total coli form count and total E. coli, were not in conformity with both World Health Organisation (WHO, 2011) Standard for drinking water and Federal Ministry of Environment (FME) 2006 standard for soil and thus constitute a threat to the River;these are attributed to waste dumps and anthropogenic activities around the five stations. The presence of bacteria in water can cause cholera, hepatitis, dysentery and typhoid. The microbial constituents can be reduced by chlorination.展开更多
The increased consumption of azithromycin during the COVID-19 pandemic may have led to its presence in the waterways. This study aims to evaluate the effect of this situation on aquatic bacteria. Methodology: Over a f...The increased consumption of azithromycin during the COVID-19 pandemic may have led to its presence in the waterways. This study aims to evaluate the effect of this situation on aquatic bacteria. Methodology: Over a four-month period following the official recognition of the COVID-19 outbreak in Yaoundé, water samples were collected from four rivers selected on the basis of their vicinity to care centers for COVID-19. Bacteria within azithromycin’s spectrum of activity were isolated, and the antibiotic’s efficacy was tested against the most frequently isolated species. The influence of COVID-19 incidence and other external factors was also assessed. Results: The most frequently isolated bacteria were Bacillus spp., Enterococcus spp., Listeria spp. and Staphylococcus epidermidis. These strains exhibited varying levels of sensitivity to azithromycin, ranging from 0% to 100%. The observed resistance rates were 12.5%, 14.29%, 16.67%, and 0%, respectively. Neither COVID-19 incidence, proximity to hospitals, nor rainfall significantly influenced bacterial resistance rates to azithromycin (P > 0.05). These resistance levels may be attributed to the relatively short exposure of bacteria to azithromycin at the sampled locations, as well as the impact of agricultural and livestock-related chemicals, such as biocides and antibiotics, present in the watershed. Conclusion: These results highlight the need to integrate into anti-COVID-19 activities, the monitoring of bacteria’s sensitivity in aquatic environments.展开更多
基金supported by the Interuniversity Cooperation ProgramScientific Research between Spain and Morocco. A/5712/06 Project:Study of Bacterial Biodiversity Present in Sebou River Using Classical Microbiology and Molecular (DGGE and FISH) Techniques
文摘Tannery wastewater causes serious ecological and sanitary damage. Chemical analysis of water from Binlamdoune River of the medina of Fez was conducted and the results revealed the presence of toxic elements from tanneries and other industrial activities, which strongly affected water quality. To determine the effectiveness of bioremediation for depollution, we studied the abundance and diversity of bacteria residing in these polluted environments. Conducting denaturing gradient gel electrophoresis （PCR-DGGE） of the 16S rDNA area using primers related to bacteria showed a bacterial community belonging to eubacterial groups, that is, Epsilonproteobacteria, Clostridia, Lactobacillales, Bacteroidetes, Gammaproteobacteria, and Alphaproteobacteria. In addition, cloning displayed the presence of clones belonging to the Firmicutes group. Moreover, scanning electron microscopy revealed a significant heterogeneity of microorganism forms and structures. These endogenous microbes could have a significant role in the purification of Binlamdoune River and Fez tannery wastewater.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.40973073,40830744)the Shanghai Leading Academic Discipline Project(Grant No.S30109)the Innovation Foundation of Shanghai University
文摘Oil contaminated soil was collected from Huangpu River-Yangtze River estuary wetland, with the aim of isolating oil-degrading microorganisms and evaluating their ability to degrade diesel. Three bacterial strains were discovered and identified by sequencing their 16S rDNA genes, two were Pseudomonas and one was Alcaligcnes. The proper growth conditions of each bacterium were measured and presented for diesel biodegradation. Biodegradation assays revealed that the degradation rates of three bacterial strains were 42.5%, 14.6% and 15.9% in 7 d respectively. They all play an important role on the nalkanes within the range of C16-C25 components of diesel. The results indicated that the oil-degraders can adapt to degrade diesel. The bacterial strains can be used in wetland diesel pollution control.
基金This work was supported by the National 973 Great Foundation Research Item of China (2002CB412303) and the National Natural Science Foundation of Jiangsu Province (BK2004118).
文摘Objective To measure the acute toxicity of halogenated benzenes to bacteria in natural waters and to study quantitative relationships between the structure and activity of chemicals. Methods The concentration values causing 50% inhibition of bacteria growth （24h-IC50） were determined according to the bacterial growth inhibition test method. The energy of the lowest unoccupied molecular orbital and the net charge of carbon atom of 20 halogenated benzenes were calculated by the quantum chemical MOPAC program. Results The logl/IC50 values ranged from 4.79 for 2,4-dinitrochlorobenzene to 3.65 for chlorobenzene. A quantitative structure-activity relationship model was derived from the toxicity and structural parameters： logl/IC50 =-0.531（ELUMO）＋1.693（Qc）＋0.163（logP）＋3.375. This equation was found to fit well （r^2=0.860, s=0.106）, and the average percentage error was only 1.98%. Conclusion Halogenated benzenes and alkyl halogenated benzenes are non-polar narcotics, and have hydrophobicity-dependent toxicity. The halogenated phenols and anilines exhibit a higher toxic potency than their hydrophobicity, whereas 2,4-dinitrochlorobenzene is electrophile with the halogen acting as the leaving group.
文摘The aim of the study was to analyse and identify microbial constituents in the water and sediment samples with comparison of the River to World Health Organisation (WHO, 2011) standard for drinking water and Federal Ministry of Environment (FME, 2006) and their public health implications with respect to water quality. The microbial assay of Otamiri River was investigated using Standard plate count. The result indicates that microbial constituents of Otamiri river obtained at five strategic gauge stations designated SSWS1 (Egbu), SSWS2 (Timber Market), SSWS3 (FUTO), DOWNSTREAM (Mbirichi) and CONTROL POINT with mean Total coliform Count of 3.0 × 102, 3.0 × 103, 4.1 × 103 and 1.0 × 103 cfu/100ml with control point value of 0.5 × 103 respectively. The mean Total Bacteria Count was 3.0 × 104, 2.1 × 103, 1.1 × 103 and 0.8 × 103 cfu/100ml respectively with control point value of 0.2 × 103 while the mean values for Total E. coli Count were 1.1 × 102, 3.0 × 102, 4 × 103 and 2.0 × 103 cfu/100ml with control point value of 0.2 × 103. The biochemical identification of some organisms in water was Escherichia coli, Vibro spp., Klebsiella spp., and Entrobacteria spp. The result of stream sediment samples indicates that the mean Total Bacterial Count was 3.5 × 104, 5.0 × 104, 6.5 × 104 and 2.0 × 104 cfu/g respectively with 1.5 × 102 as control point value and that of Total Coliform Count was 6.5 × 103, 2.0 × 103, 2.5 × 103 and 0.8 × 103 cfu/g respectively with control point value of 0.5 × 102. While for the Total E. coli Count, the values were 2.5 × 103, 1.0 × 103, 2.5 × 103 and 0.5 × 105 cfu/g respective with control as 0.5 × 102. Biochemical identification of some organisms in sediments includes: Escherichia coli, Vibro spp., Klebsiella spp., Entrobacteria spp. and Bacillus spp. The mean total bacterial count, total coli form count and total E. coli, were not in conformity with both World Health Organisation (WHO, 2011) Standard for drinking water and Federal Ministry of Environment (FME) 2006 standard for soil and thus constitute a threat to the River;these are attributed to waste dumps and anthropogenic activities around the five stations. The presence of bacteria in water can cause cholera, hepatitis, dysentery and typhoid. The microbial constituents can be reduced by chlorination.
文摘The increased consumption of azithromycin during the COVID-19 pandemic may have led to its presence in the waterways. This study aims to evaluate the effect of this situation on aquatic bacteria. Methodology: Over a four-month period following the official recognition of the COVID-19 outbreak in Yaoundé, water samples were collected from four rivers selected on the basis of their vicinity to care centers for COVID-19. Bacteria within azithromycin’s spectrum of activity were isolated, and the antibiotic’s efficacy was tested against the most frequently isolated species. The influence of COVID-19 incidence and other external factors was also assessed. Results: The most frequently isolated bacteria were Bacillus spp., Enterococcus spp., Listeria spp. and Staphylococcus epidermidis. These strains exhibited varying levels of sensitivity to azithromycin, ranging from 0% to 100%. The observed resistance rates were 12.5%, 14.29%, 16.67%, and 0%, respectively. Neither COVID-19 incidence, proximity to hospitals, nor rainfall significantly influenced bacterial resistance rates to azithromycin (P > 0.05). These resistance levels may be attributed to the relatively short exposure of bacteria to azithromycin at the sampled locations, as well as the impact of agricultural and livestock-related chemicals, such as biocides and antibiotics, present in the watershed. Conclusion: These results highlight the need to integrate into anti-COVID-19 activities, the monitoring of bacteria’s sensitivity in aquatic environments.
