米根霉不同菌丝体形态对重复间歇发酵生产L-乳酸的影响

Effect of Mycelia Morphology of Rhizopus oryzae on Repeated Intermittent Fermentation of L-lactic Acid

研究米根霉在3L发酵罐重复间歇发酵过程中,菌体形态对发酵强度的影响。结果表明:絮状米根霉首批发酵产L-乳酸为105.8g/L,葡萄糖转化率88.12%,球状米根霉产L-乳酸105.0g/L,葡萄糖转化率87.50%;在重复间歇发酵过程中,球状米根霉前6批产L-乳酸均保持在80.00g/L以上,第7批产L-乳酸78.60g/L,葡萄糖转化率均高于87.33%,产酸效率最高可达到4.26g/(L·h),而絮状米根霉前4批产L-乳酸可保持在80.00g/L以上,第5批产L-乳酸78.30g/L,第6批产L-乳酸77.40g/L,第7批产L-乳酸70.20g/L,产酸效率最高可达4.07g/(L·h)。研究数据显示,球状米根霉更适于重复间歇发酵生产L-乳酸。

The effect of Rhizopus oryzae strain on fermentation intensity of L-lactic acid during repeated intermittent fermentation in a 3 L fermentor were investigated.Results demonstrated that the yields of L-lactic acid were 105.8 g/L and 105.0 g/L through in the first batch fermentation by Rhizopus oryzae strain in flocs-form and pellet-form,and glucose conversion rates were 88.12 % and 87.50%,respectively.The average yield of L-lactic acid fermentation through Rhizopus oryzae strain in pellet-form was more than 80.00 g/L during the first 6 repeated intermittent fermentations.The glucose conversion rate was higher than 87.33%,and the highest L-lactic acid productivity was 4.26 g/（L·h）.However,the yield of L-lactic acid was decreased to 78.60 g/L in the 7th batch fermentation.The average yield of L-lactic acid fermentation through Rhizopus oryzae strain in flocs-form was more than 80.00 g/L during the first 4 repeated intermittent fermentations.But the yield of L-lactic acid was decreased to 78.30,77.40 g/L and 70.20 g/L in the following 3 batches of fermentation.The highest productivity for L-lactic acid reached up to 4.07 g/（L·h）.