甲烷利用菌催化烯烃环氧化的底物选择性, 细胞失活原因及产物对映体组成

研究了甲烷利用菌Methylomonas sp. GYJ3, Methylomonas sp. S, Methylomonas sp. Z201,Methylococcus capsulatus IMV3021, Methylosinus trichosporium IMV3011休止细胞催化烯烃环氧化的底物选择性, 细胞失活原因以及产物对映体组成。发生不同菌株和底物的环氧化活性不同。甲烷利用菌只能催化短链烯烃环氧化, 环烯烃和芳香烯烃无反应。对烯丙基型底物而言, 取代基大小和极性影响环氧化活性。丙烯环氧化活性最高, 烯丙醇不能环氧化。细胞失活的主要原因是环氧化产物的细胞毒性和反应体系中辅酶NADH损耗。手性气相色谱揭示甲烷利用菌催化烯烃环氧化形成外消旋产物。

Substrate selectivity, cell deactivation, enantiomeric composition in epoxidation of alkenes catalyzed by methane-utilizing bacteria

Substrate selectivity, reasons for cell deactivation, enantiomeric composition of products in the epoxidation of alkenes catalyzed by methane-utilizing bacteria resting cell (Methylomonas sp. GYJ3, Methylomonas sp. S, Methylomonas sp. Z201, Methylosinus trichosporium IMV3011, Methylococcus capsulatus IMV3021) were studied. There were different epoxidizing activities for various bacterial strains and various substrates. Methane-utilizing bacteria were unable to epoxidize cyclohexene and srgrene, but short-chain alkenes. Activity of epoxidation was related to steric effect of allyl substrates XCH2CH=CH2(X=H, Cl, Br, OH). The main reasons for cell deactivation were cell-toxicity of products and lost of coenzyme NADH. Chiral capillary gas chromatography revealed that epoxidizing products of alkenes were racemic epoxides.