一株具有产酸能力的芽孢杆菌的筛选及性能检测

Screening and Performance Testing of an Acid Producing Bacillus Strain

为了分离具有产酸能力的芽孢杆菌,使用菌种分离培养基从牛粪中分离得到一株具有产酸能力的芽孢菌,命名为GF1。根据该菌株的生理生化特性鉴定和16SrDNA序列测定分析,初步鉴定该菌为蜡样芽孢杆菌。对GF1发酵液中的代谢产物进行液相色谱分析,发现GF1可代谢产生乳酸、乙酸等有机酸。对GF1进行液体发酵,通过在沸水中加热10min灭活菌体,检测GF1最终芽孢率可达到90%以上,对GF1进行耐热、耐酸和耐胆盐处理,发现GF1具有良好的耐热性能和较强的耐酸耐胆盐特性,以小鼠做安全性试验,结果成活率为100%,表明GF1安全无毒。GF1不仅能够产酸,还可以产生芽孢,可以突破乳酸菌在颗粒料中添加的瓶颈。

A strain of bacillus capable of acid-producing, named CP1, was isolated from cow dung using selective cultures. Based on the sequencing of 16S rDNA and Biolog test, the isolate GF1 was pre-liminarily identified as a strain of Bacillus Cereus. The metabolites of the strain of GF1 were analyzed by the sensitive HPLC, and studies showed that it produced lactic acid, acetic acid, propionate, butyrate and so on. The strain of GF1 was cultured at 37 ℃ ,220 rpm for 48 h, with the treatment of 85℃ water bath heating for 15 min to inactivate the cells that did not form spores, the final bacillus rate of the GF1 was 90% or more. The experiments of heat, acid and bile salt-resistant treatment were carried, and the strain of GF1 showed well performance. It demonstrated that the strain of GF1 was innoxious to mice with the salty tests, the survival rate was 100%. GF1, an acid producing bacillus strain, which is a good bacteria can survive in the pellet feed , and can be used instead of lactobacillus in the pellet feed.