摘要
用亚硝基胍(NTG)和紫外线(UV)诱变处理出发菌株T_(6-13),定向筛选α-氨基β-羟基戊酸(AHV)和S-(2-氯基乙基)-L-半胱氨酸(AEC)抗性突变株和蛋氨酸缺陷型,得一苏氨酸产生菌M_(8-31)(AHV^rAEC^rMet^-),可积累L-苏氨酸6.7mg/ml。再以M_(8-31)为出发菌株,进一步提高抗性和筛选α-氨基-4-乙硫丁酸(Eth)敏感突变株,获得一苏氨酸高产菌株ME7(AHV^rAEC^rMet^-Eth^s),在含有葡萄糖10%的培养基中发酵48h可积累L-苏氨酸17.5mg/ml。
Brevibacterium flavum Te_(6-13) a glutamate producer, was treated with N-methyl-N'-nitro-N-nitrosoguanidine(NTG) and ultra-violet(UV) rays. As a result, a meth-ionine auxotrophic mutant M_(8-31) was derived which was resistant to both a-amino-β-h drox valeric acid(AHV) and S-(2-aminoeth 1)-L-cysteine (AEC). It accumu-lated 6.7mg/ml of L-threonine. With M_(8-31), as a starting strain, after receiving mi-xture mutational treatment with UV+LiC1 and NTG,a 2-amino-d-eth Isulphobutanoicacid(Eth) sensitive mutant ME_7 was obtained. It produced 17.5mg/ml of L-threoninein a medium containing 10% glucose in 48 hours at 33℃.
关键词
苏氨酸
产生菌
选育
Threonine
Mutation breeding
Auxotrophie mutant
Analogue resistant mutant
