内切葡聚糖酶产生菌的分离、筛选和识别

Isolation,screening and identification of endoglucanase producing bacteria

采用6种培养基对淡水水库、反刍动物粪便和植物组织共3种环境来源的110份样品进行微生物纯培养物的分离、培养,获得414株细菌纯培养物,其中171株来源于淡水水库环境,70株来源于反刍动物粪便,173株来源于植物内生环境。以羟甲基纤维素钠（CMC-Na）作为唯一碳源对新分离菌株进行内切葡聚糖酶活性筛选,在活性初筛中获得阳性菌197株,复筛验证确认149株为内切葡聚糖酶产生菌。通过16SrRNA基因序列分析初步确定了具内切葡聚糖酶活性菌株的分类学信息,其中64株产酶活性菌株来源于淡水水库环境,归属于10个科的11个属,19株活性菌株来源于反刍动物粪便,归属于10个科的10个属,66株活性菌株来源于植物内生环境,归属于16个科的19个属。实验表明在纤维素储备丰富的自然环境中,具内切葡聚糖酶活性的细菌资源丰富多样,值得进一步深入研究。

A total of 110 samples were collected from the following three types of environment,freshwater reservoir,ruminant animal feces and endophytic environment,which were used to isolate bacterial strains using six isolation media.As a result,a total of 414 isolates were purified,among which 171 strains were isolated from fresh water reservoir,70 strains were from ruminant animal feces,and 173 strains were endophytic bacteria.The medium containing sodium carboxymethyl cellulose（CMC-Na）as the sole carbon source was used to screen the endoglucanase producing strains.In this study,197 strains showed endoglucanase activity in preliminary screening,among which 149 strains were confirmed to be endoglucanase producing strains by re-screening experiments.These endoglucanase producing strains were identified based on the 16 SrRNA gene sequence analysis.According to the statistical results,64 endoglucanase producing strains affiliated to 11 genera of 10 families were from freshwater reservoir,19 strains affiliated to 10 genera of 10 families were from ruminant animal feces,and 66 strains affiliated to 19 genera of 16 families were from endophytic environment.These results demonstrated that microorganisms with endoglucanase activities are abundant in the natural resources where cellulose is rich,which are worthy of further research.