一株产纤维素酶细菌的筛选、鉴定及其纤维素酶的部分特性

Screening and Identification One Bacteria Producing Cellulase and Partial Characteristics of Cellulase

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。

Objective： To screen the bacteria of producing eellulase in composite and identify, and study the characteristics of ceUulase. 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 phylogenefie tree was eoustrueted 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 resuhs accord with Bacillus cereus ,and/AM 12605（T） was the closest relative with 99.8% sequence similarity. The GCH- 1 strain could produce maximum cellulase after fermented 48 hours, optimal ctthure 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 extracenular cellulase.