【摘要】 从现代牧业集团塞北牧场的规模化沼气工程沼液中分离得到10株芽孢杆菌,其中3株可以促进沼气产生,通过实验室模拟沼气发酵试验,发现其中LAM-CQ-3菌株可以明显促进沼气的产生,沼气产量比对照提高126.72%。通过形态特征、生理生化特征、(G+C)mol%含量及16S rRNA序列分析等鉴定该菌为弯曲芽孢杆菌(Bacillus flexus)。LAM-CQ-3的特征为菌体杆状,革兰氏染色阳性,最适生长温度为35℃,最适生长pH为7.5,最适生长盐浓度为5%,与Bacillus flexus IFO15715T的相似性为99.58%,(G+C)mol%含量为46.6 mol%,主要脂肪酸组成为anteisoC 15:0(30.35%),isoC 15:0(22.59%),anteisoC 17:0(16.74%),isoC 17:0(10.24%),C 16:0(5.20%)。以16S rDNA序列为基础构建了包括16株邻近种属细菌在内的系统发育树,其中与模式弯曲芽孢杆菌的同源性最近。更多还原

【Abstract】 10 strains belong to the genus Bacillus were isolated from biogas slurry of a largescale anaerobic digester on Saibei dairy farm of Mordern Farming Corporation in Hebei,among which 3 strains were proved to be able to facilitate methanogenesis according to the results of simulated anaerobic digestion experiment in laboratory,and strain LAM-CQ-3 was selected for further study.The strain LAM-CQ-3 was identified and characterized based on colony morphological,physio-biochemical characteristic and sequencing of 16S rRNA.The strain had optimum growth temperature of 35℃,optimum growth pH of 7.5 and optimum growth salinity of 5%.The genomic G+C content was 46.6mol%.The 16S rRNA gene sequence analysis revealed that strain LAM-CQ-3 was a member of the Genus Bacillus,and was most closely related to Bacillus flexus,showing 99.58% sequence similarity.The major fatty acids of strain LAM-CQ-3 were anteisoC 15:0(30.35%),isoC 15:0(22.59%),anteisoC 17:0(16.74%),isoC 17:0(10.24%),C 16:0(5.20%).On the basis of its phenotypic and genotypic properties,strain LAM-CQ-3 was identified as Bacillus flexus LAM-CQ-3.The simulated methanogenesis experiment results showed that strain LAM-CQ-3 may possess potential to be used in anaerobic digestion.更多还原