烧鸡中产芽孢菌的分离鉴定及耐受性比较研究

从烧鸡中筛选出产芽孢菌，探究高温巴氏杀菌后烧鸡腐败的主要原因。利用划线纯化法、革兰氏染色法结合芽孢染色法从烧鸡及其卤汤中筛选出产芽孢菌，然后对菌株进行16S rRNA分析及生理生化鉴定，确定菌株的种属，并对菌株的生长曲线及耐盐、耐酸和耐热性进行研究。结果表明：从烧鸡及其卤汤中共筛选分离出4 株革兰氏阳性芽孢杆菌，分别为海水芽孢杆菌（Bacillus aquimaris）、黄海芽孢杆菌（Bacillus marisflavi）、甲基营养型芽孢杆菌（Bacillus methylotrophicus）和地衣芽孢杆菌（Bacillus licheniformis），其中，地衣芽孢杆菌的生长繁殖速度最快，至6 h就基本进入生长稳定期；海水芽孢杆菌和黄海芽孢杆菌的耐盐性最强，在NaCl质量浓度达到12 g/100 mL时仍然有部分存活；甲基营养型芽孢杆菌的耐酸性最强，在pH值4.5条件下培养6 h后菌落数能够达到约8（lg（CFU/mL））；在4 株产芽孢菌中，地衣芽孢杆菌的耐热性最强，且不受处理温度和时间的影响。

Isolation and Identification of Spore-Forming Bacteria from Braised Chicken and Comparison of Their Environmental Tolerance

This study was conducted to select spore-forming strains from braised chicken for the purpose of figuring out the major cause of its spoilage after high-temperature pasteurization. The target strains were isolated from braised chicken and the remaining marinade by the streak plate method as well as through Gram staining and spore staining and were identified as Bacillus by 16S rRNA analysis and physiological and biochemical characterization. Their growth curves and tolerance to salt, acid and heat were investigated. The results indicated that a total of four Gram-positive Bacillus were obtained and they were identified as B. aqimaris, B. marisfavi, B. methyltrophicus and B. licheniformis. Among them, B. licheniformis grew fastest, which entered the stationary phase of growth at 6 h. In the presence of 12 g/100 mL NaCl solution, B. aquimaris and B. marisflavi survived partially, showing the highest salt tolerance. B. methylotrophicus could grow to ~ 8 (lg (CFU/mL)) after 6 h cultivation at pH 4.5, having the highest acid resistance. B. licheniformis was the most heat resistant among the four strains , which was not affected by heat treatment temperature and time.