3株魏斯氏菌的分离鉴定与生物学特性研究

Isolation, identification and biological characteristics of 3 strains of Weissella

中文关键词:  四川泡菜  魏斯氏菌  安全特性  益生特性

英文关键词:Sichuan pickle  Weissella  safety properties  probiotic properties

中文摘要:

      目的 对泡菜发酵初期魏斯氏菌进行分离鉴定, 并探究其安全特性和益生特性。方法 采用平板对细菌进行分离, 进行分离菌株生理生化鉴定和16S rDNA测序鉴定, 检测其代谢产物毒性, 抗生素敏感性, 耐药基因, 评价细菌的耐酸、耐胆盐、耐人工肠液、黏附能力、对胆固醇及甘油三酯的降解能力、抗氧化能力以及抑菌能力。结果 共筛选出3株魏斯氏菌, 命名为融合魏斯氏菌C13、食窦魏斯氏菌G232和W212; 3株菌代谢产物无毒性, 对14类21种抗生素表现出不同程度耐药, 耐药基因检测C13携带四环素类耐药基因(tetM), G232和W212携带磺胺类耐药基因(sulII); 3株菌能耐受pH 2~4和3.0 g/L以下的胆盐, 在人工肠液中3 h后存活率超过76.80%; 3株菌的黏附能力好, 疏水性为60.47%~62.69%, 自凝聚率为43.76%~52.55%, 共凝聚率为43.20%~61.58%; 对胆固醇及甘油三酯的降解主要在前15 h; 表现出一定的抗氧化能力, 对1,1-二苯基-2-三硝基苦肼自由基清除率较高(清除率25.69%~58.12%), 对超氧阴离子自由基清除率相对较低(10.08%~35.29%); 3株菌对志贺氏菌、大肠杆菌等致病菌抑菌活性好(抑菌圈直径18.22~42.18 mm)。结论 本研究结果表明筛选的3株魏斯氏菌有较好的安全性和一定的益生特性, 为将来魏斯氏菌在实际生产的应用提供基础数据。

英文摘要:

      Objective To isolate and identify Weissella in the initial stage of pickle fermentation, and explore its safety and probiotics characteristics. Methods The bacteria were isolated by using plating method, followed by physiological and biochemical identification and 16S rDNA sequencing identification. Further bacterial metabolites toxicity, anti-drug sensitivity, resistance genes detection, evaluation of bacterial acid resistance and bile salt resistance, artificial intestinal fluid resistance, adhesion ability, cholesterol and triglyceride degradation ability, antioxidant ability, and antibacterial ability were tested. Results The results showed that 3 strains of Weissella were screened, identified and named as Weissella confusa C13, Weissella cibaria G232 and W212. The metabolites of the 3 strains were non-toxic and they showed different degrees of resistance to 14 classes of 21 kinds of antibiotics. The resistance gene detection showed that C13 carried the tetracycline resistance gene tetM, G232 and W212 carried the sulfonamide resistance gene sulII. The 3 strains could tolerate with pH 2-4 and bile salts below 3.0 g/L, and the survival rate after 3 hours in artificial intestinal fluid was more than 76.80%. The 3 strains had good adhesion ability, with hydrophobicity between 60.47% and 62.69%, self-aggregation rates between 43.76% and 52.55%, and coaggregation rates between 43.20% and 61.58%. The degradation of cholesterol and triglyceride was mainly in the first 15 hours. It showed certain antioxidant capacity, with a high scavenging rates of 1,1-diphenyl-2-trinitropyrazine free radical (25.69%?58.12%) and a relatively low scavenging rates of superoxide anion free radical (10.08%?35.29%). The 3 strains had good antibacterial activity against pathogenic bacteria such as Shigella and Escherichia coli (the diameters of bacteriostatic circle were 18.22?42.18 mm). Conclusion The results of this study shows that the 3 strains of Weissella has good safety and certain probiotic characteristics, which provides basic data for the application of Weissella in food production in the future.