耐温性L-谷氨酸发酵菌种的选育

Breeding of a thermotolerant Brevibacterium tianjinese for producing L-glutamic acid

应用基因组改组技术提高L-谷氨酸生产菌在高温发酵条件下的谷氨酸产量。以天津短杆菌T6-13变异株SW 07-1为原始亲株,分别经紫外线(UV)-硫酸二乙酯(DES)和X射线诱变,获得5株耐温性能略有提高的突变菌株。经2轮基因组改组,获得耐高温(能在44℃生长)的L-谷氨酸菌株F2-50。F2-50在38℃下,摇瓶发酵40 h,发酵液中L-谷氨酸浓度比原始出发菌株提高了近41%,在41℃高温下,摇瓶发酵40 h,L-谷氨酸浓度比原始出发菌株提高了近2倍。

The breeding of thermotolerant L-glutamic acid producing strain by genome shuffling was investigated. A variant of Brevibacterium tianjinese T6-13, SW07-1 was used as the parent strain. Five mutants with subtle improvement in characteristic of heat resistance were generated by UV-DES （diethyl sulfate mutagenesis） and X-rays, respectively. A strain F2-50 capable of growing at 44 ~C and with higher L-glutamic acid productivity was obtained from the second round genome shuffled population. The L-glutamic acid production of F2-50 was 0.41 and 2 times higher than that of the initial strain at 38 ℃ and 40 ℃, respectively.