酸白菜腌制过程中优势乳酸菌及菌群演替规律研究

Studies on the Dominant Lactic Acid Bacteria and Microbial Community Succession Lawin Pickled Cabbage

以陕西杨凌地区大白菜为原料,切碎,添加2.5%食盐,在22℃进行半厌氧自然发酵酸泡菜。发酵过程中在不同时间取泡菜液,测定泡菜pH值、乳酸菌落和菌落总数变化,分离鉴定优势乳酸菌株,检测酸白菜微生物多样性,探究酸白菜腌制过程中菌群的演替变化规律。结果表明:泡菜自然发酵,从第0天到第7天,pH值从初始的6.0降到4.2,乳酸菌数由4.65 lg(CFU/mL)增至7.86 lg(CFU/mL),菌落总数由9.11 lg(CFU/mL)减至8.65 lg(CFU/mL)。在不同发酵阶段共分离鉴定出27株乳酸菌,分别为10株明串珠菌,7株魏斯氏菌,4株乳酸乳球菌,4株弯曲乳杆菌和2株戊糖片球菌。泡菜发酵起始优势乳酸菌种属为魏斯氏菌,发酵中期优势乳酸菌逐渐变成乳酸乳球菌,肠膜明串珠菌演替成优势乳酸菌。整个泡菜发酵阶段异型乳酸发酵菌种占据主导地位,发酵中、后期(5 d后)同型乳酸发酵菌种参与泡菜发酵。

Taking Chinese cabbage as raw material,pickled cabbage was produced by natural fermentation at 22℃with 2.5%salt.Collected the brine at different time during the fermentation process to measure the pH value,detect the number of lactic acid bacteria and total bacteria,isolate and identify the dominant lactic acid bacteria strain,analyze the microbial diversity and the succession of bacterial community during pickled cabbage.The results showed that during the natural fermentation of kimchi,the pH value of kimchi decreased from 6.0 to 4.15,the total number of lactic acid bacteria increased from 4.65 lg(CFU/mL)to 7.86 lg(CFU/mL),and the total number of bacteria decreased from 9.11 lg(CFU/mL)to 8.65 lg(CFU/mL).A total of 27 strains of lactic acid bacteria were isolated from different stages,in cluding 10 strains of Leuconostoc,7 strains of Weissiella,4 strains of Lactococcus lactis,4 strains of Lactobacillus Campylobacter and 2 strains of Lactococcus pentosus.During the 7-days fermentation of kimchi,the dominant species of lactic acid bacteria gradually changed from Wessella to Lactococcus lactis,and finally the mesenteric candida successively became the dominant lactic acid bacteria.The heteromorphic lactic acid fermentation bacteria occupied the dominant position in the whole kimchi fermentation stage,and the homologous lactic acid fermentation bacteria participated in the kimchi fermentation in the middle and later stage of fermentation.