摘要
以氨水为中和剂,替代CaCO3,对耐氨米根霉R.oryzaeJS-N0-2-02进行15L自动发酵罐的分批和分批补料发酵及其发酵动力学的初步研究,结果表明,降低起始糖浓度,产酸期补糖可明显提高菌体L-乳酸比生产速率和耗糖产酸能力,提高L-乳酸产量和纯度,降低残糖。在发酵起始时添加1 g/L CaCO3能进一步提高补糖发酵的L-乳酸比生产速率,增强发酵后期菌体耗糖产酸能力,从而进一步提高L-乳酸产量和纯度,降低残糖。发酵结果:起始糖浓度为120 g/L,25h时补糖使最终发酵总糖浓度达137 g/L,发酵培养60 h,L-乳酸产量可达101.8 g/L,纯度97.3%,菌体耗糖转化率76%,比生产速率0.27 g/g.h,残糖降至3 g/L。
With ammonia water as nertralizer, L- lactic acid batch and fed batch fermentation by ammonia resistant mutant Rhizopus oryzae JS- N02 - 02 were conducted in a 15L fermentor. The kinetics of growth and L- lactic acid production were also studied. Compared with batch fermentation, the results showed that with lower initial corn hydrolysate concentration and feeding glucose at L- lactic acid-producing period, could not only increase the L- lactic acid specific productivity, specific glucose consuming rate and glucose acid conversion rate, but also increase the yield of L- lactic acid and its purity. It is also seen that the glucose residual was lower.When 1 g/L CaCO3 was added at the initial medial, the L- lactic acid specific productivity of glucose-feeding fermentation could be remarkably increased, and the capabily of the strain to eonver glucose to L- lactic acid was improved at the later period of fermentation. Therefore, the yield of L- lactic acid and its purity could be further increased and the glucose residual could be further lowed. When the initial glucose concentration was 120 g/L and the total glucose concentration was controlled at 137 g/L by glucose feeding after 25h, the results showed that： the yield of L- lactic acid was 101.8 g/L, the purity of L- lactic acid was 97.3 %, glucose-acid conversion rate was 76 %, specific productivity was 0.27g/（g. h）, and the residual glucose was 3 g/L.
出处
《食品与发酵工业》
CAS
CSCD
北大核心
2005年第12期30-34,共5页
Food and Fermentation Industries
关键词
米根霉
氨水中和
分批补料发酵
L-乳酸
发酵动力学
Rhizopus oryzae, ammonia neutralization, fed - batch fermentation, L- lactic acid, fermentation kinetics
