Breeding of Producing L-Valine Strain Brevibacterium flavum NJ112 by Protoplast Fusion Technology

摘要

With Brevibacterium flavum NVT1103 (Leu~1, α-AB~(hr), 2-TA~(hr), SG~r) and JVHK597 (Leu~-, Ile~-, Met~l, α-AB~r, 2-TA~r) as parental strains, conditions of two parental strains' protoplast formation and regeneration were groped about. On this basis, a series of protoplast fusion experiment were conducted to investigated the influence of fusion temperature in the fusion process, poly(ethylene glycol) concentration and the fusion time. Under unoptimized conditions, the L-valine production of the strain NJ112 derivative in flasks was 45.6 g/L.