鼠李糖乳杆菌乳酸发酵特性及碳氮源研究

通过对鼠李糖乳杆菌利用碳源、氮源能力的研究,探讨菌株产酸的最佳发酵条件。结果表明：高质量浓度葡萄糖对菌体的生长和乳酸发酵有一定的抑制作用;酵母粉是鼠李糖乳杆菌生长和产L-乳酸最理想的氮源,使用廉价的氮源黄豆粉和无机氮源硫酸铵替代培养基中的酵母粉,可以使产酸量基本不变。在接种量5%的情况下,以酵母粉为氮源,当葡萄糖初始质量浓度为60mg/mL时,在恒温厌氧箱培养48h,L-乳酸产量为48.25mg/mL,产率为80.53%。

Optimal Carbon and Nitrogen Sources for Lactic Acid Production by Lactobacillus rhamnosus and Fermentation Dynamics

The abilities of Lactobacillus rhamnosus to utilize various carbon and nitrogen sources were examined with the aim of finding optimal carbon and nitrogen sources for lactic acid production by Lactobacillus rhamnosus.It was indicated that glucose was the best carbon source although it at high concentrations had a certain inhibitory effect on Lactobacillus rhamnosus growth and lactic acid production.Yeast extract was the best nitrogen carbon for Lactobacillus rhamnosus growth and lactic acid production.Basically the same lactic acid production was obtained when yeast extract was replaced with other cheap nitrogen carbons such as soybean meal or ammonium sulfate.The lactic acid yield and productivity were 48.25 mg/mL and 80.53%,respectively after 48 h of culture in a medium containing yeast extract as the nitrogen source and glucose as the carbon nitrogen at an initial concentration of 60 mg/mL under thermostatic anaerobic conditions.