浓酱兼香型酒醅中乳酸菌的分离鉴定及布氏乳杆菌生长特性分析

Isolation and identification of lactic acid bacteria and growth characteristic of Lactobacillus buchneri in fermented grains of strong-sauce-flavor Baijiu

采用平板分离法,从浓酱兼香型不同轮次酒醅中分离乳酸菌,并采用分子生物学技术进行鉴定,同时测定不同布氏乳杆菌(Lactobacillus buchneri)的生长特性。结果表明,共分离到30株乳酸菌,归属于3个属共5个种,其中布氏乳杆菌最多(21株),占总分离菌株数的70%,是第三和第四轮出池酒醅的优势乳酸菌。所检测的19株布氏乳杆菌(L. buchneri)的最适生长温度为37℃,最适生长p H值大多在4.5左右,对乙醇的耐受能力在2%~10%之间。与植物乳杆菌(Lactobacillus plantarum)相比,所检测的6株布氏乳杆菌表现出了较强的发酵产柠檬酸和乙酸的能力,其平均柠檬酸产量为3.76 g/L,平均乙酸产量为4.22 g/L,分别是植物乳杆菌(L. plantarum)ZR1的11.13倍和1.80倍。

The lactic acid bacteria were isolated by plate separation method from different rounds of fermented grains of strong-sauce-flavor Baijiu(Chinese liquor), and identified by molecular biological technology. At the same time, the growth characteristics of different Lactobacillus buchneri were determined. The results showed that a total of 30 strains of lactic acid bacteria were isolated, belonging to three genera and five species. Among them,L. buchneri was the most(21), accounting for 70% of the total isolates, which were the dominant lactic acid bacteria in the third and fourth rounds of the unloading pit. The optimum growth temperature of the tested 19 strains of L. buchneri was 37 ℃, the optimum p H was mostly around 4.5, and the tolerance to ethanol was between 2% and 10%. Compared with Lactobacillus plantarum, the tested 6 strains of L. buchneri showed a strong ability to produce citric acid and acetic acid by fermentation, their average citric acid and acetic acid yield was 3.76 g/L and 4.22 g/L, which was 11.13 times and1.80 times that of L. plantarum ZR1, respectively.