禁食条件下草鱼肠粘膜可培养纤维素降解菌的分离与鉴定

Isolation and identification of major cellulase-producing bacteria in intestines of Ctenopharyngodon idellus under fasting conditions

为探究草鱼(Ctenopharyngodon idellus)肠道固有纤维素降解菌群及其酶活,从冬天禁食条件下的野生草鱼肠道粘膜分离培养的细菌中随机挑取22个单菌落,经筛选得到8株纤维素降解细菌,测量了它们降解纤维素所产生的水解圈的大小,并进行了16 S rDNA序列测定。结果显示,不同细菌(菌株)之间纤维素降解能力存在显著差异(F=4.03,P<0.05),其中GCM4和GCM8的纤维素降解能力较强,D/d值分别为4.37和4.14;GCM1的纤维素降解能力较弱,D/d值为1.99。序列测定结果表明,菌GCM1与碘短杆菌(Brevibacterium iodinum)相似性达99%,GCM2-GCM7与温和气单胞菌(Aeromonas sobria)相似性达到99%,GCM8与Bacillus indicus相似性达99%。

In order to explore Ctenopharyngodon idellus inherent cellulase - producing bacteria and their enzyme activity, randomly picked 22 single strains of bacteria in the intestinal mueosa were isolated and cuhured from wild C. idellus in the winter under fasting conditions. Total 8 cellulase - producing strains were screened from the intestinal mueosa of wild C.idellus, and the diameter of hydrolyzing zones and colonies by degradation of cellulose were measured. Cellulose degradation capacity exited a significant difference （F= 4.03, P 〈0.05） between the different bacteria （strain）, and strain GCM4 and GCM8 were stronger while GCM1 was the weaker, the D/d values were 4.37, 4.14 and 1.99, respectively. 16 S rDNA genotype identification indicated that GCM1, GCM2 - GCM7, GCM8 were related （99% similarities） to Brevibacterium iodinum, Aeromonas sobria, Bacillus indicus, respectively.