S-adenosyl-L-methionine ( SAM) was a type of active amino acid showing strong demand, and the main manufacture method of SAM was synthesis catalyzed by Pichia pastoris. In order to elevate SAM productivity, the alternative feeding strategy of methanol and glycerol established previously was optimized here. Firstly, the producing Pichia strain that over-expressed SAM synthetase from Streptomyces spetabilis was constructed, then the initial cell density of induction phase and alternative mode of methanol and glycerol were improved, and finally the influence of peptone addition on SAM accumulation was investigated. The result showed that the optimal condition was as follows: the initial cell density of induction phase was kept at 170 g/L, the period of feeding glycerol was extended step by step, and 0. 5% peptone was supplemented. Under the condition, the maximal accumulation level of SAM was achieved at 14.7 g/L after 88 h,and the productivity was obtained at 167.0 mg/L/h, 45.6% higher than that before optimization.%S-腺苷甲硫氨酸(S-adenosyl-L-methionine,SAM)是一种需求量巨大的活性氨基酸,而利用毕赤酵母催化合成SAM是主要生产方法.为提高SAM产率,本文对前期构建的表达源于天蓝色链霉菌SAM合成酶的重组毕赤酵母菌的甲醇-甘油交替补料发酵策略进行了优化.并考察了补加蛋白胨对SAM积累的影响.结果显示最佳策略为控制诱导起始细胞密度170 g/L,逐步延长诱导后期甘油流加时间,并添加0.5％蛋白胨.SAM在88 h积累量达14.7 g/L,产率提高45.6％,达167.0 mg/L/h.
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