一株产纤维素酶细菌的筛选、鉴定及产酶条件优化

Screening,Enzyme-producing Conditions Optimized and the 16S rDNA Sequences Analyzed of a Cellulose Decomposing Bacteria

目的:筛选1株产纤维素酶的细菌。方法:通过对从腐烂朽木及其附近土壤中得到的样品进行富集培养、分离纯化得到16株纤维素分解菌,经刚果红染色鉴定和液体发酵培养后对其进行了菌种初步鉴定及产酶条件的初步优化。结果:获得1株纤维素酶分泌量较高的细菌LT3。结论:LT3为革兰氏阳性菌,菌体成杆状,经发酵优化培养后,较适产酶条件为甘蔗渣20g/L,pH7.0、30℃培养120h,CMC酶活为71.17U/mL,滤纸酶活为33.37U/mL。通过克隆其16S rDNA序列,对其进行系统进化分析,鉴定为蜡状芽孢杆菌。

Objective：To obtain a Cellulose-degrading bacteria.Method： Sixteen strains of different microorganisms with ability to degrade cellulose were obtained by screening the decaying deadwood and soil nearby.In the screening program, accumulation culture,isolation,purification,Congo red dying and liquid fermentation were applied successively.Initial optimization of bateria cultivation conditions for cellulose activity were performed.Result：The most potent isolates（strain LT3） was obtained.Conclusion： LT3 strain was identified as Bacillus cereus which was recognized as gram-positive Bacteria with rod-shaped mycelium.Identification was carried out using morphological and biochemical properties along with 16S rDNA partial sequence analysis.Experiments also indicated that the optimum enzyme-producing conditions were pH 7.0 with 20g/L bagasse at 30 degrees for 120h,the CMCase reached 71.17 U/mL and the FPase was 33.37U/mL.