【摘要】 考察了5 L自控发酵罐变温控制和酵母抽提物流加工艺对L-苏氨酸补料分批发酵过程的影响。结果表明:在发酵前12 h温度为37℃,12 h后温度升高至39℃,可同时获得最大细胞生物量和L-苏氨酸产量;在此基础上,发酵后期连续流加2.0 g/L酵母抽提物可有效地降低副产氨基酸的生成,稳定L-苏氨酸发酵产酸水平,最高产酸质量浓度达105.8 g/L,糖酸转化率达到47.5%。更多还原

【Abstract】 The effects of differential temperature-shift and yeast extract feeding methods on L-threonine fermentation are studied in 5 L fermentor.The results show that the maximum biomass and the maximum L-threonine yield are obtained by the strategy in which 37℃ is used for fermentation for the first 12 h and the temperature is switched to 39℃ after 12 h.Based on these results,byproduct amino acids are significantly decreased and the level of L-threonine yield is stabilized by the continuous feeding of 2.0 g/L yeast extract in latter period.Finally,the L-threonine yield is up to 105.8 g/L,the conversion rate of glucose is 47.5%.更多还原