Process for the production of L-lysine by the fermentation of a mutant strain of Corynebacterium glutamicum and isolation of the said strain

摘要

This invention relates to an improved process for the production of L-lysine by the fermentation of the mutant strain Corynebacterium glutamicum LNBT-221 under aerobic conditions at a temperature between 30 and 38 degree C and a pH of 6-8. This new mutant has the ability to utilize an extensive range of substrates, including carbohydrates and acetate. The fermentation means may contain complex organic sources of carbon and/or nitrogen as well as closely specified chemically synthesized means. The L-lysine which accumulates outside the cells in the fermentation medium can be recovered therefrom using appropriate techniques such as e.g. the use of ion exchange resins. Its scope also includes a process for the isolation of a new mutant strain of Corynebacterium glutamicum LNBT-221 which was selected after mutagenesis of the parent strain, Corynebacterium glutamicum LNBT-20, which was in turn derived from Corynebacterium glutamicum ATCC 21513, with N-methyl-N'-nitro-N-nitrosoguanidine. The mutant strain LNBT-221 was selected on the basis of its hypersensitivity to monofluoroacetate and is capable of overproducing L-lysine in quantities greater than those produced by the strains from which it was derived.