Environmental pollution with petroleum and petrochemical products such as diesel and used oils has been recognized as one of the most serious current problem in the world, especially in developing countries. These pet...Environmental pollution with petroleum and petrochemical products such as diesel and used oils has been recognized as one of the most serious current problem in the world, especially in developing countries. These petrochemical products devastate the soil, surface and underground waters and alter the microbial population at the polluted sites. Thus, the present work aims to optimize the biodegradation of diesel and two used oils (SAE 40 and SAE 50) by bacterial strains namely Acinetobacter S2 and Pseudomonas S7 using either nutrient factors (yeast extract, peptone or trace elements) or surfactants (tween 80 or Sodium Dodecyl Sulfate: SDS). The strains are incubated alone or together with the used oils or diesel supplemented or not with nutrient factors or surfactants for 14, 28, 42 and 56 days, respectively. For all the incubation period, the hydrocarbons degradation rates are determined by gravimetric assay. The results obtained show that nutrient factors increase significantly SAE 50 used oil biodegradation (p = 0.009). Similarly, tween 80 increases SAE 50 and SAE 40 used oils biodegradation but not diesel one. The results also show a significant difference between biodegradation rates at 14, 28, 42 and 56 days for all the hydro-carbons tested (p Acinetobacter S2 and Pseudomonas S7 increases the degradation over the one of the strains alone.展开更多
Water purification with Moringa oleifera seeds has received a lot of attention because it reduces water turbidity and pathogenic microorganisms. However, it is important to define the optimum conditions of storage to ...Water purification with Moringa oleifera seeds has received a lot of attention because it reduces water turbidity and pathogenic microorganisms. However, it is important to define the optimum conditions of storage to preserve the treated water quality. The study aims to investigate microbial quality of water treated with Moringa oleifera seeds or cake coagulants in relation to the storage temperature and shelf life in order to define the optimum conditions of storage. A total of 45 water samples from 3 water reservoirs of Loumbila, Ziga and Ouaga 3 dams were collected in sterile glass bottles and treated in triplicate with Moringa oleifera seeds or defatted cakes coagulants. Treated water samples obtained at optimum conditions were stored at room temperature (25°C - 30°C) and at 4°C. Fecal bacteria pollution indicators (Escherichia coli, fecal coliforms and fecal streptococcus) and parasites were monitored every 24 hours during three (3) days based on laboratory standard methods. Data were analyzed using the Student’s t-test and XLSTAT 7.5.2 statistical software. From the results obtained, bacterial indicators increased significantly with storage temperature (p and shelf life (p . However, for all water samples, bacterial growth was more important in samples treated with Moringa oleifera cakes than seeds (p . For water samples treated with Moringa oleifera seeds and stored at room temperature, bacterial increase after 72 hours was 57 - 80, 42 - 50 and 22 - 47 CFU/100 ml for fecal coliforms, E. coli and fecal streptococcus, respectively. With Moringa oleifera cake’s treatment, the increase was 63 - 104, 57 - 82 and 28 - 52 for the same indicators, respectively. Bacterial growth was also more important at room temperature than at 4°C. Thus, microbiological quality of water treated with Moringa oleifera seeds was better than cakes whatever storage temperature and shelf life. Overall, water treated with Moringa oleifera seeds should be stored at low temperature and consumed within 24 hours.展开更多
文摘Environmental pollution with petroleum and petrochemical products such as diesel and used oils has been recognized as one of the most serious current problem in the world, especially in developing countries. These petrochemical products devastate the soil, surface and underground waters and alter the microbial population at the polluted sites. Thus, the present work aims to optimize the biodegradation of diesel and two used oils (SAE 40 and SAE 50) by bacterial strains namely Acinetobacter S2 and Pseudomonas S7 using either nutrient factors (yeast extract, peptone or trace elements) or surfactants (tween 80 or Sodium Dodecyl Sulfate: SDS). The strains are incubated alone or together with the used oils or diesel supplemented or not with nutrient factors or surfactants for 14, 28, 42 and 56 days, respectively. For all the incubation period, the hydrocarbons degradation rates are determined by gravimetric assay. The results obtained show that nutrient factors increase significantly SAE 50 used oil biodegradation (p = 0.009). Similarly, tween 80 increases SAE 50 and SAE 40 used oils biodegradation but not diesel one. The results also show a significant difference between biodegradation rates at 14, 28, 42 and 56 days for all the hydro-carbons tested (p Acinetobacter S2 and Pseudomonas S7 increases the degradation over the one of the strains alone.
文摘Water purification with Moringa oleifera seeds has received a lot of attention because it reduces water turbidity and pathogenic microorganisms. However, it is important to define the optimum conditions of storage to preserve the treated water quality. The study aims to investigate microbial quality of water treated with Moringa oleifera seeds or cake coagulants in relation to the storage temperature and shelf life in order to define the optimum conditions of storage. A total of 45 water samples from 3 water reservoirs of Loumbila, Ziga and Ouaga 3 dams were collected in sterile glass bottles and treated in triplicate with Moringa oleifera seeds or defatted cakes coagulants. Treated water samples obtained at optimum conditions were stored at room temperature (25°C - 30°C) and at 4°C. Fecal bacteria pollution indicators (Escherichia coli, fecal coliforms and fecal streptococcus) and parasites were monitored every 24 hours during three (3) days based on laboratory standard methods. Data were analyzed using the Student’s t-test and XLSTAT 7.5.2 statistical software. From the results obtained, bacterial indicators increased significantly with storage temperature (p and shelf life (p . However, for all water samples, bacterial growth was more important in samples treated with Moringa oleifera cakes than seeds (p . For water samples treated with Moringa oleifera seeds and stored at room temperature, bacterial increase after 72 hours was 57 - 80, 42 - 50 and 22 - 47 CFU/100 ml for fecal coliforms, E. coli and fecal streptococcus, respectively. With Moringa oleifera cake’s treatment, the increase was 63 - 104, 57 - 82 and 28 - 52 for the same indicators, respectively. Bacterial growth was also more important at room temperature than at 4°C. Thus, microbiological quality of water treated with Moringa oleifera seeds was better than cakes whatever storage temperature and shelf life. Overall, water treated with Moringa oleifera seeds should be stored at low temperature and consumed within 24 hours.
