Screening Of Microbacterium Hydrocarbonoxydans Mutation For Production Of Lactamase

(-)-γ-Lactam is one of the key starting materials for the synthesis of two powerful antiviral agents (-)-cabovir and (-)-abacavir. The production of (-)-γ-Lactam using enzymatic resolution of racemic γ-lactam was studied in the paper.Microbiacterium Hydrocarbonoxydans L29-9preserved in our laboratory producing lactamase, was treated with Ultraviolet light and diethyl sulfate. A mutant L29-9-B-4with high yield of lactamase and high stability was obtained, and its enzyme activity increased from45U/g to539U/g as compared with the original strain.Ferment conditions of strain L29-9-B-4, including carbon sources, nitrogen sources, pH, and culturing time, were optimized as following: amylum6g/L, beef extract5g/L, N-actylphenylalanine4g/L, pH7.0, temperature30℃, culturing for40h. Biotransformation using whole cells of the strain was carried out at30℃for2h, giving (-)-γ-lactam with ee99.8%.Several immobilized methods were studied. The results showed that the united entrapping with polyvinyl alcohol and calcium alginate gave the best effect.