摘要
以丙烯氧化反应为指标研究了不同外源电子给体对甲烷细菌(Methylomonas sp.GYJ30)休止细胞催化活性的影响。结果表明甲烷、甲醇、甲醛和甲酸盐作为电子给体加入反应中,将甲烷单加氧酶催化丙烯环氧化反应活性分别提高5.3,12.7,10和12.4倍。以甲烷和甲醛作为外源电子给体时提高初始浓度对甲烷单加氧酶具有抑制作用;而以甲醇和甲酸盐作为电子给体时提高初始浓度对甲烷单加氧酶催化活性无明显抑制作用。研究了甲醇作为电子给体时它的代谢、环氧丙烷的积累以及催化反应活性与反应时间的关系。
Effect of exogenous electron donors on activity of MMO of Mehtylomonas sp. GYJ3 were studied. The results indicated that methane, methanol, formaldehyde and formate as electron donors were able to enhance the rates of propylene eposidation ct-alyzed by MMO. The initial concentration of these electron donors added to reaction system greatly influenced the raes of propylene epoxidation. At the optimum initial concentration of methane , methanol, formaldehyde and formate, the activities of MMO were stimulated to enhance 5. 3, 12. 7, 10 and 12. 4 fold of intrinsic activity, respectively. Methane and formaldehyde becomes toxic to MMO at high concentrations. Formate, an ideal electron donor, was shown to stimulate activity of MMO without apparent inhibition at relatively high concentrations up to 130um. The metabolism of methanol, the accumulation of propylene oxide and the activity of MMO in course of reaction time were studied with propylene epoxidation by restingcell of Mehtylmnonas sp. GYJ3 at initial concentration of 1. 5mmol/L methanol. The results revealed that the metabolic rate of methanol and regeneration rate of NADH were much higher that the rates of propylene epoxidation and almost unvaried with reaction time. However, the rates of propylene e-poxidation were lower with reaction time, suggesting that the propylene oxide was inhibitory to MMO at relatively high concentrations.
出处
《生物工程学报》
CAS
CSCD
北大核心
1996年第3期322-326,共5页
Chinese Journal of Biotechnology
基金
国家自然科学基金资助项目
关键词
电子给体
甲烷单加氧酶
丙烯环氧化
生物技术
Methanotrophic bacteria , methane monooxygenase, electron donors , propy-lene epoxidation
