棒状链霉菌F613-1的诱变及其发酵工艺优化

该实验旨在获得克拉维酸高产菌株，并通过发酵条件优化提高其产量。以棒状链霉菌（Streptomyces clavulans）F613-1为出发菌株，通过紫外和亚硝基胍（NTG）联合诱变及含链霉素固定培养基筛选并在对突变菌株添加发酵前体研究基础上，通过单因素试验和响应面法优化其摇瓶发酵条件。结果表明，成功筛选一株棒状链霉菌衍生菌株，克拉维酸产量较出发菌株提高19.9%；添加1.5%甘油和0.15%谷氨酸可大幅缩短突变株发酵时间；突变株前36 h时25 ℃培养，后37 h时29 ℃培养，发酵pH值为7，克拉维酸产量达5.44 g/L，较出发菌株提高了55.8%。棒状链霉菌高产菌株的摇瓶发酵条件优化效果显著，为进一步提高克拉维酸生产提供依据。

Mutagenesis and fermentation process optimization of Streptomyces clavulans F613-1

To obtain high-yield strain and increase the yield of clavulanic acid by fermentation conditions optimization, Streptomyces clavulans F613-1 was mutagenized by UV and nitrosoguanidine (NTG), and selected by solid medium with streptomycin resistance screening method. On the basis of adding fermentation precursors, the shaking flask fermentation conditions of the mutant were optimized by single factor tests and response surface method. The experimental results showed that a strain derived from S. clavulanum was successfully obtained, and the clavulanic acid yield of the mutant strain was 19.9% higher than that of the original strain. The fermentation time of the mutant was significantly reduced by the addition of glycerol 1.5% and glutamic acid 0.15%. The mutant was cultured at 25 ℃ before fermentation 36 h and at 29 ℃ after fermentation 37 h, and the yield of clavulanic acid reached 5.44 g/L in pH 7, increased by 55.8% than the original strain. The optimization of shaking flask fermentation conditions of S. clavulans was remarkable, which provided a basis for further improving the production of clavulanic acid.