微生物发酵法生产L-丝氨酸的研究

The Studies on Fermentation of L-Serine

S112是经诱变获得的抗丝氨酸结构类似物和分解能力缺陷的突变株,丝氨酸产率是1 6g/l。摇瓶试验初糖50g/l,发酵37h时补糖40g/l,可有效提高产酸率50%左右。分批培养补氮试验表明补充氮源同时补糖与只补糖相比,产酸率差异不明显,说明丝氨酸产生菌产丝氨酸过程对氮源的需求不高。经发酵培养基氮源的筛选,认为10%鱼粉水解液是最优的。在7升发酵罐试验,没有补糖的情况下46h开始产丝氨酸,46、54、58、62、66和72h产酸率大致相同,为1 8g/l。

S112 is a mutant strain of anti-serine structural analogue and deficient in decomposition ability which produces1.6 g/l serine.In shaking culture test that initial sugar 50 g/l and supplemental sugar 40 g/l after fermenting 37 hours could increase production about 50%. Supplemental nitrogen test in batch culturd indicate that the difference in serine production isn't apparent between simultaneous supplemental sugar nitrogen and single supplemental sugar.The phenomenon suggests that the strain of serine-producing doesn't need much nitrogen.10% fish powder hydrolyzate is optimal by screening fermentation culture medium. The strain began to produce serine after 46 hours culture under no supplemental sugar. The serine production is roughly the same after fermenting 46 h、54 h、58 h、62h、66 h and 72 h which is 1.8 g/l.