清香型白酒酒醅中乳酸高产菌株的筛选及乳酸的分离纯化

该研究以分离自清香型白酒酒醅的10株乳酸菌为研究对象，采用溶钙圈法和液体发酵法从中筛选高产乳酸菌株，并对其产乳酸条件进行考察；然后通过活性炭和离子交换柱对乳酸进行分离纯化，并通过高效液相色谱（HPLC）法检测乳酸纯度。结果表明，植物乳杆菌（Lactobacillus plantarum）SL32-2为高产乳酸的菌株，其在高粱糖化液中产乳酸的最佳发酵温度和初始pH值分别为35 ℃和7.0。活性炭对其发酵液的最适处理条件为活性炭添加量1.5 g/100 mL、处理温度60 ℃、处理时间2 h，此时脱色率、脱糖率和脱蛋白率分别为72.65%、3.75%和85.81%。经离子交换柱进一步纯化后，乳酸总得率为51.12%，其中阴离子交换柱的洗脱液中乳酸纯度较高。

Screening of high-yield lactic acid strains from fermented grains of light-flavor Baijiu and isolation and purification of lactic acid

In this study, using 10 strains of lactic acid bacteria isolated from fermented grains of light-flavor Baijiu (Chinese liquor) as research objects, the high-yield lactic acid strains were screened by calcium-soluble circle method and liquid fermentation method, and the conditions for lactic acid production were studied. The lactic acid was separated and purified by activated carbon and ion exchange column, and the purity of lactic acid was detected by HPLC. The results showed that Lactobacillus plantarum SL32-2 was a high-yield lactic acid strain, and the optimum fermentation temperature and initial pH for lactic acid production in sorghum saccharification solution were 35 ℃ and 7.0, respectively. The optimal treatment conditions of activated carbon on the fermentation broth were activated carbon addition 1.5 g/100 ml, treatment temperature 60 ℃ and time 2 h. Under the conditions, the rate of decolorization, sugar removal and protein removal were 72.65%, 3.75% and 85.81%, respectively. The crude lactic acid was further purified by ion exchange column, the total yield of lactic acid was 51.12%, and its purity was high in eluent with ion exchange column.