聚γ-谷氨酸高产突变株的选育及摇瓶发酵条件

Screening of High Productive Mutant of γ–Polyglutamic Acid and Its Fermentation Conditions

对地衣芽孢杆菌(Bacilluslicheniformis)进行亚硝基胍和60Co诱变,获得一株γ PGA的高产菌株C9.γ PGA质量浓度由9.44g/L提高到19.76g/L,提高了109%.突变株传代10次,质量浓度保持基本稳定.通过正交试验和单因素试验对发酵培养基及发酵条件进行了优化.当发酵培养基中含柠檬酸12g/L、甘油80g/L、L 谷氨酸23g/L、氯化铵7g/L,pH7.0,装液量为50mL/250mL三角瓶,接种体积分数为5%时,37℃摇瓶发酵72h,γ PGA达到23.32g/L.

A high productive mutant of γ-PGA was obtained from Bacillus licheniformis WBL-3 with mutagenesis by NTG and ^(60)Co. The concentration of γ-PGA was increased from 9.44 g/L to 19.76 g/L and the mutant showed genetic stability during 10 generations.The medium composition and the cultivation conditions were optimized by orthogonal and single factor experiment.When the mutant C_(9 )was cultivated with inoculation size of 5%, at 37 ℃, pH 7.0, for 72 hours, in the medium containing 12 g/L citric acid, 80 g/L glycerol, 23 g/L L- glutamic acid, and 7 g/L ammonium chloride, the final concentration of γ-PGA reach 23.32 g/L.