A hydrocarbon degrading bacterium KL2-13 was isolated from ten sites of oil contaminated soil in the Karamay oilfield. It was identified as the Bacillusfusiformis sp. bacterium based on its morphological and physiolog...A hydrocarbon degrading bacterium KL2-13 was isolated from ten sites of oil contaminated soil in the Karamay oilfield. It was identified as the Bacillusfusiformis sp. bacterium based on its morphological and physiological characteristics and the 16S rDNA sequence analysis. The factors influencing the hydrocarbon degradation by the bacterium KL2-13 were determined. The test results have showed that the hydrocarbon degrading bacterium KL2-13 requires an optimum pH range of 6-8, and the optimum inoculation quantity is 3%. The low-concentration metal ions Fe^2＋, Mg^2＋ and Ca^2＋can improve the degradation ability of the bacteria KL2-13. A too low concentration of Tween-80 does not show obvious promotion to the degrading bacterium KL2-13, and an excessively high concentration can decrease the degradation ability of the bacterium, the best dosage of which is 2%. The hydrocarbon degrading rate reached 59.07%4-0.37% under the optimum culture conditions.展开更多
After incubation for 6 -30 h, with the rapid increase of bacterial cell number, surface tension of bacterium BS-8 was reduced sharply from 63.2 mN/m to 39.4 mN/m. The production of biosurfactants by BS-8 was growth-de...After incubation for 6 -30 h, with the rapid increase of bacterial cell number, surface tension of bacterium BS-8 was reduced sharply from 63.2 mN/m to 39.4 mN/m. The production of biosurfactants by BS-8 was growth-dependent. Using glucose as the carbon source, bacterium BS-8 was incubated. Based on centrifugation, precipitation and chromogenie reaction of the culture solution, results indicated that the biosurfactants belonged to lipopeptides. The yield of biosurfaetants isolated and purified from the culture solution was 0.58 g/L, and the critical micelle concentration （CMC） was 90 mg,/L. Under conditions of pH 4 -9, tem- perature 20 -70 ℃, NaCl concentration 1% -6%, biosurfactants predueed by BS-8 exhibited the highest stability.展开更多
In this study, a cellulose-degrading bacterium was isolated from paddy soils in Chengdu City. After 2 d of culture, the average diameter of hydrolytic circles on CMC-Congo red medium was 26 -30 mm. Single colonies on ...In this study, a cellulose-degrading bacterium was isolated from paddy soils in Chengdu City. After 2 d of culture, the average diameter of hydrolytic circles on CMC-Congo red medium was 26 -30 mm. Single colonies on LB plates were white and wrinkled. The isolated strain was identified as a Gram-negative bacterium by Gram staining, which could produce short red-like spores. Colony PCR was performed using the bacterial 16S rDNA universal primers. A 1 429 kb DNA fragment was amplified. Based on sequence homology analysis and comprehensive analysis, the isolated strain was identified as Bacillus velezensi, which was named CDBV62 according to the origin.展开更多
One in 58 strains of bacteria isolated from the compost showed clear colonies after a few days of growth on the plates containing medium made of only agar and water.Water suspension contained only agar (2 and 8g·...One in 58 strains of bacteria isolated from the compost showed clear colonies after a few days of growth on the plates containing medium made of only agar and water.Water suspension contained only agar (2 and 8g·L -1 ) with two controls (normal saline,LB medium) was inoculated with the bacterium BR5-1 to see whether there was an increasement of the alive bacteria concentration after 48 h of the growth.The results showed that there was a significant rising of the alive bacteria concentration in the agar susp...展开更多
The purpose of this experiment was to isolate and screen the microorganisms from the soil where chicken feathers were piled for a long time and identify them biologically.Single-factor test and response surface method...The purpose of this experiment was to isolate and screen the microorganisms from the soil where chicken feathers were piled for a long time and identify them biologically.Single-factor test and response surface methodology(RSM)analyses were used to explore the optimum conditions for the growth and fermentation of a strain.Screening of bacterial strains from the soil where feathers were piled for a long time was performed,and 12 keratinolytic bacterial strains were isolated.One of these isolates,CH-7,was found to be the most effective feather-degrading strain,which was identified as Lactococcus lactis KU568489.1.The growth situation of feather keratin degrading bacterium analysis results showed that the best degradation effect of CH-7 was found in oxygen,inoculation 5%,initial pH=6.5,fermentation temperature 30℃,speed 220 r·min-1 and fermentation time 36 h,and CH-7 had the highest degradation rate of feather keratin.The optimization analysis of RSM showed that there was more significances of the three factors,32℃,pH 6.3 and amount of inoculum at 5.7%on the degradation of feather keratin.Based on the above results,the feather degrading bacterium,Lactococcus lactis CH-7,was obtained by screening,30℃and pH 5.5-6.5 were the best growth conditions.The oxygen,the amount of inoculum 5.7%,the fermentation temperature,32℃,pH 6.3 and the rotational speed 220 r·min-1 were the best fermentation conditions.Under these conditions,38.48%degradation rate was obtained after 36 h fermentation,which demonstrated the strain CH-7 was potential to the fermented feather meal for feed.展开更多
Ibuprofen(IBU)is widely used in the world as anti-inflammatory drug,which posed health risk to the environment.A bacterium capable of degrading IBU was isolated from activated sludge in a sewage treatment plant.Accord...Ibuprofen(IBU)is widely used in the world as anti-inflammatory drug,which posed health risk to the environment.A bacterium capable of degrading IBU was isolated from activated sludge in a sewage treatment plant.According to its morphological,physiologic,and biochemical characteristics,as well as 16S rRNA sequence analysis,the strain was identified as Serratia marcescens BL1(BL1).Degradation of IBU required the presence of primary substrate.After a five-day cultivation with yeast powder at 30℃ and pH 7,the highest degradation(93.47%2.37%)was achieved.The process of BL1 degrading IBU followed first-order reaction kinetics.The BL1 strain was applied to a small biological aerated filter(BAF)device to form a biofilm with activated sludge.IBU removal by the BAF was consistent with the results of static tests.The removal of IBU was 32.01% to 44.04% higher than for a BAF without BL1.The indigenous bacterial community was able to effectively remove CODMn(permanganate index)and ammonia nitrogen in the presence of BL1.展开更多
基金supports provided by the Science Research and Technology Developing Program, CNPC (2008D-4704-2): "Microbial remediation technology of high-temperature and arid oil polluted soil"
文摘A hydrocarbon degrading bacterium KL2-13 was isolated from ten sites of oil contaminated soil in the Karamay oilfield. It was identified as the Bacillusfusiformis sp. bacterium based on its morphological and physiological characteristics and the 16S rDNA sequence analysis. The factors influencing the hydrocarbon degradation by the bacterium KL2-13 were determined. The test results have showed that the hydrocarbon degrading bacterium KL2-13 requires an optimum pH range of 6-8, and the optimum inoculation quantity is 3%. The low-concentration metal ions Fe^2＋, Mg^2＋ and Ca^2＋can improve the degradation ability of the bacteria KL2-13. A too low concentration of Tween-80 does not show obvious promotion to the degrading bacterium KL2-13, and an excessively high concentration can decrease the degradation ability of the bacterium, the best dosage of which is 2%. The hydrocarbon degrading rate reached 59.07%4-0.37% under the optimum culture conditions.
基金Supported by Key Science and Technology Program of Henan Province(132102310253,122102310350)Natural Science Research Program of Education Department of Henan Province(15A210020,12A180008)
文摘After incubation for 6 -30 h, with the rapid increase of bacterial cell number, surface tension of bacterium BS-8 was reduced sharply from 63.2 mN/m to 39.4 mN/m. The production of biosurfactants by BS-8 was growth-dependent. Using glucose as the carbon source, bacterium BS-8 was incubated. Based on centrifugation, precipitation and chromogenie reaction of the culture solution, results indicated that the biosurfactants belonged to lipopeptides. The yield of biosurfaetants isolated and purified from the culture solution was 0.58 g/L, and the critical micelle concentration （CMC） was 90 mg,/L. Under conditions of pH 4 -9, tem- perature 20 -70 ℃, NaCl concentration 1% -6%, biosurfactants predueed by BS-8 exhibited the highest stability.
文摘In this study, a cellulose-degrading bacterium was isolated from paddy soils in Chengdu City. After 2 d of culture, the average diameter of hydrolytic circles on CMC-Congo red medium was 26 -30 mm. Single colonies on LB plates were white and wrinkled. The isolated strain was identified as a Gram-negative bacterium by Gram staining, which could produce short red-like spores. Colony PCR was performed using the bacterial 16S rDNA universal primers. A 1 429 kb DNA fragment was amplified. Based on sequence homology analysis and comprehensive analysis, the isolated strain was identified as Bacillus velezensi, which was named CDBV62 according to the origin.
基金Supported by National High-tech Research and Development Program of China (863 Program) (20060110Z4023)
文摘One in 58 strains of bacteria isolated from the compost showed clear colonies after a few days of growth on the plates containing medium made of only agar and water.Water suspension contained only agar (2 and 8g·L -1 ) with two controls (normal saline,LB medium) was inoculated with the bacterium BR5-1 to see whether there was an increasement of the alive bacteria concentration after 48 h of the growth.The results showed that there was a significant rising of the alive bacteria concentration in the agar susp...
基金Supported by Harbin Applied Technology Research and Development Project(2016RAXXJ015)。
文摘The purpose of this experiment was to isolate and screen the microorganisms from the soil where chicken feathers were piled for a long time and identify them biologically.Single-factor test and response surface methodology(RSM)analyses were used to explore the optimum conditions for the growth and fermentation of a strain.Screening of bacterial strains from the soil where feathers were piled for a long time was performed,and 12 keratinolytic bacterial strains were isolated.One of these isolates,CH-7,was found to be the most effective feather-degrading strain,which was identified as Lactococcus lactis KU568489.1.The growth situation of feather keratin degrading bacterium analysis results showed that the best degradation effect of CH-7 was found in oxygen,inoculation 5%,initial pH=6.5,fermentation temperature 30℃,speed 220 r·min-1 and fermentation time 36 h,and CH-7 had the highest degradation rate of feather keratin.The optimization analysis of RSM showed that there was more significances of the three factors,32℃,pH 6.3 and amount of inoculum at 5.7%on the degradation of feather keratin.Based on the above results,the feather degrading bacterium,Lactococcus lactis CH-7,was obtained by screening,30℃and pH 5.5-6.5 were the best growth conditions.The oxygen,the amount of inoculum 5.7%,the fermentation temperature,32℃,pH 6.3 and the rotational speed 220 r·min-1 were the best fermentation conditions.Under these conditions,38.48%degradation rate was obtained after 36 h fermentation,which demonstrated the strain CH-7 was potential to the fermented feather meal for feed.
基金funded by the National Natural Science Foundation of China(Grant Nos.21767013 and 51741805)the Natural Science Foundation of Jiangxi Province(No.20151BA B213018).
文摘Ibuprofen(IBU)is widely used in the world as anti-inflammatory drug,which posed health risk to the environment.A bacterium capable of degrading IBU was isolated from activated sludge in a sewage treatment plant.According to its morphological,physiologic,and biochemical characteristics,as well as 16S rRNA sequence analysis,the strain was identified as Serratia marcescens BL1(BL1).Degradation of IBU required the presence of primary substrate.After a five-day cultivation with yeast powder at 30℃ and pH 7,the highest degradation(93.47%2.37%)was achieved.The process of BL1 degrading IBU followed first-order reaction kinetics.The BL1 strain was applied to a small biological aerated filter(BAF)device to form a biofilm with activated sludge.IBU removal by the BAF was consistent with the results of static tests.The removal of IBU was 32.01% to 44.04% higher than for a BAF without BL1.The indigenous bacterial community was able to effectively remove CODMn(permanganate index)and ammonia nitrogen in the presence of BL1.
