【摘要】 目的:分离堆肥中具有产纤维素酶酶活的菌株并进行鉴定,同时进行该菌株纤维素酶酶特性的研究。方法:采用刚果红平板法进行筛选得到菌株,利用16SrDNA通用引物对其基因组DNA进行扩增,测序得到GCH-1的部分16SrDNA序列,经Blastn调出与菌株16SrDNA同源的序列,用软件MEGA 4.0按照Neighbor-Joining方法构建16SrDNA系统发育树,并采用DNS法测定所产纤维素酶酶活。结果:GCH-1的生理生化指标与蜡质芽胞杆菌理化指标相符,与Bacillus cereusIAM 12605(T)处于同一分支,相似性为99.8%.GCH-1菌株发酵48h能达到最大产酶量,所产纤维素酶在40℃有最高酶活力,酶活力分别为0.581u/mL,GCH-1菌株产生的纤维素酶酶系在pH 7.0~9.0能够保持较高的相对酶活力,超过85%相对活力。结论:GCH-1初步鉴定为蜡质芽孢杆菌(Bacillus cereus),能够产胞外纤维素酶。更多还原

【Abstract】 Objective:To screen the bacteria of producing cellulase in composite and identify,and study the characteristics of cellulase.Method: The gangguo red plate method was implemented to screen the bacteria that were named as GCH-1;the part 16S rDNA was PCR using universal primer and sequenced.The 16S rDNA phylogenetic tree was constructed by comparing with published 16S rDNA sequences of relative bacteria species using Neighbor-joining,and DNS method was used to analyze enzyme activity.Result: It was main physiological and biochemical results accord with Bacillus cereus,and IAM 12605(T) was the closest relative with 99.8% sequence similarity.The GCH-1 strain could produce maximum cellulase after fermented 48 hours,optimal culture temperature were 40℃,enzyme activity were 0.581u/mL,the enzyme preparations of GCH-1 strain were stable between pH value 7.0-9.0 and relatively enzyme was beyond 85%.Conclusion: GCH-1 strain was identified as Bacillus cereus and produced extracellular cellulase.更多还原