摘要
研究了拟干酪乳杆菌(Lactobacillus paracasei)发酵生产乳酸过程中,添加维生素对菌体生长、细胞活性、产酸,以及在碳流代谢中与乳酸生物合成密切相关的4种酶[乳酸脱氢酶(LDH)、磷酸果糖激酶(PFK)、丙酮酸脱氢酶(PDC)和丙酮酸羧化酶(PC)]活性的影响。结果显示:维生素添加促进了菌体生长,使乳酸产量提高了42.47%;同时降低了发酵过程中菌体的死亡率,降低的最大幅度可达53.46%;PFK和LDH的活性比对照有提高,最大幅度达62.30%和126.65%,PDC的活性在发酵中期也有一定的提高,但PC的活性变化很小。实验结果表明:组合维生素的添加可以提高乳酸菌的活性,同时使代谢通量有利于乳酸生成。
Effects of vitamins on the cell growth, viability of L. paracasei and concentration of lactic acid were studied. Accordingly, four enzymes, which were greatly related to the glycolytic flux and lactic acid biosynthesis, were assayed. Results showed that the concentration of lactic acid, the specific activities of PFK （Phosphotyl fructose kinase） and LDH （lactic dehydrogenase） were increased by 42. 47%, 62.30% and 126.65% respectively, the viability of L. paracasei was decreased by 53.46%, and the specific activity of PDC （pyruvic dehydrogenase） was also increased during the middle period of fermentation when vitamins were added into the broth. While the specific activity of PC （pyrurate carboxylase） was not affected significantly. In conclusion, the addition of vitamins could increase the cell viability and regulate the metabolic flux of L. paracasei, which led to the improvement of lactic acid production.
出处
《华东理工大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2007年第3期330-335,共6页
Journal of East China University of Science and Technology
基金
上海市生物医药重大专项(05DZ19326)
