从堆积时间为80~100 a的铅锌矿渣中分离了6株细菌,通过测定部分16S rRNA基因序列确定了它们的系统发育地位。结果表明有3株细菌属于节杆菌属(Arthrobacter),同A.nicotinovorans和A.histidinolovorans两个种关系密切。另外3株属于壤霉菌...从堆积时间为80~100 a的铅锌矿渣中分离了6株细菌,通过测定部分16S rRNA基因序列确定了它们的系统发育地位。结果表明有3株细菌属于节杆菌属(Arthrobacter),同A.nicotinovorans和A.histidinolovorans两个种关系密切。另外3株属于壤霉菌属(Agromy-ces),同Ag.m ediolanus具有较近的亲缘关系。总体来看,这些菌株都对检测的5种重金属有高的最低抑菌浓度(m in im al inh ib itory concentration,M IC)。节杆菌对Zn、Co的耐受明显高于壤霉菌。此外,这些重金属高抗性菌株也对重金属有较强的吸附能力。在环境中有单一重金属离子的情况下,冻干的节杆菌对Pb的吸附率平均达到了约400mg/g干菌体,对Cd和Zn的吸附也分别达到了近177和80mg/g干菌体,具有进一步开发为重金属吸附剂的潜力。展开更多
A bacterial strain (AD26) capable of utilizing atrazine as a sole nitrogen source for growth was isolated from an industrial wastewater sample by enrichment culture. The 16S rRNA gene sequencing identified AD26 as an ...A bacterial strain (AD26) capable of utilizing atrazine as a sole nitrogen source for growth was isolated from an industrial wastewater sample by enrichment culture. The 16S rRNA gene sequencing identified AD26 as an Arthrobacter sp. PCR assays indicated that AD26 contained atrazine-degrading genes trzN and atzBC. The trzN gene of AD26 only differs from the trzN of Arthrobacter aurescens TC1 by one base (A→T at 907) and one amino acid (Met→Leu at 303). The specific activity of trzN of AD26 in crude cell ext...展开更多
Two kinds of micro organism, Arthrobacter sp. AX86(1,4 dehdrogenator)and Absidia sp. A28(11α hydroxylator)were used in this experiment.Two different fermentation techniques were performed to accomplish the multiple c...Two kinds of micro organism, Arthrobacter sp. AX86(1,4 dehdrogenator)and Absidia sp. A28(11α hydroxylator)were used in this experiment.Two different fermentation techniques were performed to accomplish the multiple conversional reactions for producing 16β methyl 11α,17α,21 trihydroxy 1,4 pregnadiene 3,20 dione(Ⅲ)from 16β methyl 3β,17α,21 trihydroxy 5α pregnane 20 one 21 acetate(I):1)To produce product(Ⅲ)by means of a two step fermentation method which were independently performed first by Arthrobacter and next by Absiaia, and 2)the product was obtained by a sequential fermentation system of aforesaid two micro organisms in a single fermentor without isolation of the intermediates from the mixture.Our results showed that in both fermentation systems high yield of product was obtained.However,according to the technical simplicity,shorter duration of fermentation cycle and efficient yield of product,the second method is better than the first one.展开更多
The optimal conditions of the conversion of 16α methyl 3β,17α,21 trihydroxy 5α pregnane 20 one 21 acetate to 16α methyl 11α,17α,21 trihydroxy 1,4 pregndiene 3,20 dione by the mixed cultures of Arthrobacter sp 8...The optimal conditions of the conversion of 16α methyl 3β,17α,21 trihydroxy 5α pregnane 20 one 21 acetate to 16α methyl 11α,17α,21 trihydroxy 1,4 pregndiene 3,20 dione by the mixed cultures of Arthrobacter sp 86 and Metarhizium sp 88 were studied.2%～4%( V/V )N,N dimethylformamide in the medium was used to dissolve the substrate.It could increase the conversion ability.Adding the mycelium of Metarhizium into the dehydrogenation reaction mixture during 0～28 hours had no influence on the conversion rate.The optimal concentration of mycelium was around 75 mg/mL wet weight.0.04%～0.06% CoCl 2·6H 2O inhibited the degradation of steroid nucleus so that the product was greatly accumulated.Under such condition the yeild of mixed microbial conversion was 67%.展开更多
文摘从堆积时间为80~100 a的铅锌矿渣中分离了6株细菌,通过测定部分16S rRNA基因序列确定了它们的系统发育地位。结果表明有3株细菌属于节杆菌属(Arthrobacter),同A.nicotinovorans和A.histidinolovorans两个种关系密切。另外3株属于壤霉菌属(Agromy-ces),同Ag.m ediolanus具有较近的亲缘关系。总体来看,这些菌株都对检测的5种重金属有高的最低抑菌浓度(m in im al inh ib itory concentration,M IC)。节杆菌对Zn、Co的耐受明显高于壤霉菌。此外,这些重金属高抗性菌株也对重金属有较强的吸附能力。在环境中有单一重金属离子的情况下,冻干的节杆菌对Pb的吸附率平均达到了约400mg/g干菌体,对Cd和Zn的吸附也分别达到了近177和80mg/g干菌体,具有进一步开发为重金属吸附剂的潜力。
文摘A bacterial strain (AD26) capable of utilizing atrazine as a sole nitrogen source for growth was isolated from an industrial wastewater sample by enrichment culture. The 16S rRNA gene sequencing identified AD26 as an Arthrobacter sp. PCR assays indicated that AD26 contained atrazine-degrading genes trzN and atzBC. The trzN gene of AD26 only differs from the trzN of Arthrobacter aurescens TC1 by one base (A→T at 907) and one amino acid (Met→Leu at 303). The specific activity of trzN of AD26 in crude cell ext...
文摘Two kinds of micro organism, Arthrobacter sp. AX86(1,4 dehdrogenator)and Absidia sp. A28(11α hydroxylator)were used in this experiment.Two different fermentation techniques were performed to accomplish the multiple conversional reactions for producing 16β methyl 11α,17α,21 trihydroxy 1,4 pregnadiene 3,20 dione(Ⅲ)from 16β methyl 3β,17α,21 trihydroxy 5α pregnane 20 one 21 acetate(I):1)To produce product(Ⅲ)by means of a two step fermentation method which were independently performed first by Arthrobacter and next by Absiaia, and 2)the product was obtained by a sequential fermentation system of aforesaid two micro organisms in a single fermentor without isolation of the intermediates from the mixture.Our results showed that in both fermentation systems high yield of product was obtained.However,according to the technical simplicity,shorter duration of fermentation cycle and efficient yield of product,the second method is better than the first one.
文摘The optimal conditions of the conversion of 16α methyl 3β,17α,21 trihydroxy 5α pregnane 20 one 21 acetate to 16α methyl 11α,17α,21 trihydroxy 1,4 pregndiene 3,20 dione by the mixed cultures of Arthrobacter sp 86 and Metarhizium sp 88 were studied.2%～4%( V/V )N,N dimethylformamide in the medium was used to dissolve the substrate.It could increase the conversion ability.Adding the mycelium of Metarhizium into the dehydrogenation reaction mixture during 0～28 hours had no influence on the conversion rate.The optimal concentration of mycelium was around 75 mg/mL wet weight.0.04%～0.06% CoCl 2·6H 2O inhibited the degradation of steroid nucleus so that the product was greatly accumulated.Under such condition the yeild of mixed microbial conversion was 67%.
