米根霉分批补料一步发酵法高效积累L-乳酸的研究

L-lactic Acid Production through One-step Fermentation by Rhizopus Oryzae Using an Optimal Fed-batch Culture Strategy

在前期工作中,课题组创新性的提出了米根霉一步发酵法高效积累L-乳酸的策略。为了进一步提高米根霉合成L-乳酸的生产效率,作者系统考察了葡萄糖分批补料策略对米根霉一步发酵合成L-乳酸的影响:包括不同初始葡萄糖浓度和残余葡萄糖控制策略。研究发现,控制初始葡萄糖浓度为50.0 g/L时,最有利于L-乳酸的高效积累,控制不同残余葡萄糖浓度对一步发酵法合成L-乳酸基本没有影响。在最优的分批补料条件下,L-乳酸产量和生产效率最高,分别达到了162.0 g/L和6.23 g/(L·h),与前期工作相比,生产效率提高了14.3%。

In our previous work,we proposed a novel,modified one-step fermentation fed-batch strategy to efficiently generate L-lactic acid(L-LA)using Rhizopus oryzae.In this study,to further enhance L-LA production efficiency,we systematically investigated glucose feeding approaches,including different initial glucose concentrations and residual glucose control modes,in fed-batch culture with one-step fermentation.According to our results,culture of R.oryzae using an initial glucose concentration of 50 g/L and a fed-batch strategy is an effective approach to one-step L-LA fermentation.Changing the residual glucose had no obvious effect on LA accumulation.We obtained the maximum LA production(162 g/L)and productivity(6.23 g/(L·h))during the acid production stage.Compared to our previous work,although there was almost no change in L-LA production or yield,the productivity of L-LA enhanced 14.3%.The productivity levels we observed were the highest ever reported in L-LA fermentation by R.oryzae.