高效纤维素优势分解菌的筛选和鉴定

本试验基于获得高效纤维素优势分解菌的目的,通过分离纯化初步得到30株菌株,利用刚果红染色法初筛共得到14株纤维素分解菌,并通过滤纸条崩解实验进一步进行筛选得到5株效果较好的纤维素分解菌,通过发酵产酶利用DNS显色法测定CMC酶活力和FPA酶活力最终确定了4株优势纤维素分解菌,通过测定4株菌株的羧甲基纤维素酶(CMCase)、滤纸酶(FPA)以及β-葡萄糖苷酶(β-Gase)活,验证4株纤维素优势分解菌的产酶能力,并分别命名为X-1、X-6、X-7和X-11,并将该4株优势纤维素分解菌应用于秸秆的液态发酵,其对秸秆的降解率较自然降解相比,降解率分别提高了31.92%、40.15%、35.29%和39.98%。对4株优势菌株进行了分子鉴定,根据16S r DNA序列比对结果表明,菌株X-1、X-7和X-11均为粪产碱杆菌;菌株X-6属于解糖假苍白杆菌。

Screening and identification of efficient cellulose degrading bacteria

The purpose of this study was to identify high-efficiency,dominant cellulolytic bacteria.Preliminary isolation and purification yielded 30 strains of bacteria.Preliminary screening by Congo red dye method yielded 14 strains of cellulolytic bacteria,and further screening through filter paper disintegration test yielded 5 strains of relatively effective cellulolytic bacteria.By measuring the activity level of the CMC enzyme and the FPA enzyme during the bacteria strains fermentation and enzyme production process through the DNS colorimetric method,4 strains of dominant cellulolytic bacteria were finally selected.These 4 strains of dominant cellulolytic bacteria`s enzyme production ability were verified by measuring the 4 bacteria strains' carboxymethyl cellulose enzyme(CMCase)activity,filter paper enzyme(FPA)activity and β-glycosidase enzyme(β-Gase)activity,and these 4 high-efficiency strains of bacteria were named X-1,X-6,X-7 and X-11 respectively.Then the 4 strains of dominant cellulolytic bacteria were used in the liquid fermentation of straws.Compared with the straw`s natural degradation rate,the straw`s degradation rate was improved by 31.92％,40.15％,35.29％and 39.98％respectively using the aforementioned cellulolytic bacteria.Molecular identification of the 4 dominant bacteria strains,according to 16S rDNA sequence alignment results showed that strains X-1,X-7 and X-11 belong to the Alcaligenes faecalis;strain X-6 belongs to the Pseudochrobactrum saccharolyticum.