By using acetonitrile as the sole nitrogen source, a microbial strain with high nitrilase activity, named as Alcaligenes sp. ECU0401, was newly isolated from soil, which could enantioselectively transform racemic mand...By using acetonitrile as the sole nitrogen source, a microbial strain with high nitrilase activity, named as Alcaligenes sp. ECU0401, was newly isolated from soil, which could enantioselectively transform racemic mandelonitrile into (R)-(?)-mandelic acid, with an enantiomeric excess of >99.9%.展开更多
Exploration of biodemulsifiers has become a new research aspect.Using waste frying oils（WFOs） as carbon source to synthesize biodemulsifiers has a potential prospect to decrease production cost and to improve the ap...Exploration of biodemulsifiers has become a new research aspect.Using waste frying oils（WFOs） as carbon source to synthesize biodemulsifiers has a potential prospect to decrease production cost and to improve the application of biodemulsifiers in the oilfield.In this study,a demulsifying strain,Alcaligenes sp.S-XJ-1,was investigated to synthesize a biodemulsifier using waste frying oils as carbon source.It was found that the increase of initial pH of culture medium could increase the biodemulsifier yield but decrease the demulsification ratio compared to that using paraffin as carbon source.In addition,a biodemulsifier produced by waste frying oils and paraffin as mixed carbon source had a lower demulsification capability compared with that produced by paraffin or waste frying oil as sole carbon source.Fed-batch fermentation of biodemulsifier using waste frying oils as supplementary carbon source was found to be a suitable method.Mechanism of waste frying oils utilization was studied by using tripalmitin,olein and tristearin as sole carbon sources to synthesize biodemulsifier.The results showed saturated long-chain fatty acid was diffcult for S-XJ-1 to utilize but could effectively enhance the demulsification ability of the produced biodemulsifier.Moreover,FT-IR result showed that the demulsification capability of biodemulsifiers was associated with the content of C=O group and nitrogen element.展开更多
An aerobic bacterium strain, F-3-4, capable of effectively degrading 2,6-di-tert-butylphenol(2,6-DTBP), was isolated and screened out from an acrylic fiber wastewater and the biofilm in the wastewater treatment facili...An aerobic bacterium strain, F-3-4, capable of effectively degrading 2,6-di-tert-butylphenol(2,6-DTBP), was isolated and screened out from an acrylic fiber wastewater and the biofilm in the wastewater treatment facilities. This strain was identified as Alcaligenes sp. through morphological, physiological and biochemical examinations. After cultivation, the strain was enhanced by 26.3% in its degradation capacity for 2,6-DTBP. Results indicated that the strain was able to utilize 2,6-DTBP, lysine, lactamine, citrate, n-utenedioic acid and malic acid as the sole carbon and energy source, alkalinize acetamide, asparagine, L-histidine, acetate, citrate and propionate, but failed to utilize glucose, D-fructose, D-seminose, D-xylose, serine and phenylalanine as the sole carbon and energy source. The optimal growth conditions were determined to be: temperature 37℃, pH 7.0, inoculum size 0.1% and shaker rotary speed 250 r/min. Under the optimal conditions, the degradation kinetics of 2,6-DTBP with an initial concentration of 100 mg/L was studied. Results indicated that 62.4% of 2,6-DTBP was removed after 11 d. The degradation kinetics could be expressed by Eckenfelder equation with a half life of 9.38 d. In addition, the initial concentration of 2,6-DTBP played an important role on the degradation ability of the strain. The maximum initial concentration of 2,6-DTBP was determined to be 200 mg/L. Above this level, the strain was overloaded and exhibited significant inhibition.展开更多
文摘By using acetonitrile as the sole nitrogen source, a microbial strain with high nitrilase activity, named as Alcaligenes sp. ECU0401, was newly isolated from soil, which could enantioselectively transform racemic mandelonitrile into (R)-(?)-mandelic acid, with an enantiomeric excess of >99.9%.
基金supported by the National Natural Science Foundation of China(No.50908166)the China Postdoctoral Science Foundation(No.20100480621)+2 种基金the Program for New Century Excellent Talents in University of ChinaProgram for Young Excellent Talents in Tongji University(No.2010KJ060)the International S&T Cooperation Program of China(No.2009DFA92140)
文摘Exploration of biodemulsifiers has become a new research aspect.Using waste frying oils（WFOs） as carbon source to synthesize biodemulsifiers has a potential prospect to decrease production cost and to improve the application of biodemulsifiers in the oilfield.In this study,a demulsifying strain,Alcaligenes sp.S-XJ-1,was investigated to synthesize a biodemulsifier using waste frying oils as carbon source.It was found that the increase of initial pH of culture medium could increase the biodemulsifier yield but decrease the demulsification ratio compared to that using paraffin as carbon source.In addition,a biodemulsifier produced by waste frying oils and paraffin as mixed carbon source had a lower demulsification capability compared with that produced by paraffin or waste frying oil as sole carbon source.Fed-batch fermentation of biodemulsifier using waste frying oils as supplementary carbon source was found to be a suitable method.Mechanism of waste frying oils utilization was studied by using tripalmitin,olein and tristearin as sole carbon sources to synthesize biodemulsifier.The results showed saturated long-chain fatty acid was diffcult for S-XJ-1 to utilize but could effectively enhance the demulsification ability of the produced biodemulsifier.Moreover,FT-IR result showed that the demulsification capability of biodemulsifiers was associated with the content of C=O group and nitrogen element.
文摘An aerobic bacterium strain, F-3-4, capable of effectively degrading 2,6-di-tert-butylphenol(2,6-DTBP), was isolated and screened out from an acrylic fiber wastewater and the biofilm in the wastewater treatment facilities. This strain was identified as Alcaligenes sp. through morphological, physiological and biochemical examinations. After cultivation, the strain was enhanced by 26.3% in its degradation capacity for 2,6-DTBP. Results indicated that the strain was able to utilize 2,6-DTBP, lysine, lactamine, citrate, n-utenedioic acid and malic acid as the sole carbon and energy source, alkalinize acetamide, asparagine, L-histidine, acetate, citrate and propionate, but failed to utilize glucose, D-fructose, D-seminose, D-xylose, serine and phenylalanine as the sole carbon and energy source. The optimal growth conditions were determined to be: temperature 37℃, pH 7.0, inoculum size 0.1% and shaker rotary speed 250 r/min. Under the optimal conditions, the degradation kinetics of 2,6-DTBP with an initial concentration of 100 mg/L was studied. Results indicated that 62.4% of 2,6-DTBP was removed after 11 d. The degradation kinetics could be expressed by Eckenfelder equation with a half life of 9.38 d. In addition, the initial concentration of 2,6-DTBP played an important role on the degradation ability of the strain. The maximum initial concentration of 2,6-DTBP was determined to be 200 mg/L. Above this level, the strain was overloaded and exhibited significant inhibition.
