肉牛粪污中纤维素降解菌的分离筛选

为了获得有效降解肉牛粪污中纤维素的细菌,采用以羧甲基纤维素钠为碳源的方法对牛粪及其自然堆肥样品进行纤维素降解菌的分离,对已分离菌株进行形态学和分子生物学鉴定,再结合纤维素刚果红水解圈测定和滤纸条降解试验做进一步研究。结果表明,以羧甲基纤维素钠为碳源,初步分离得到牛粪样品及堆肥中32株纤维素降解菌,进一步筛选得到有刚果红水解圈菌株4株,分别为XQ-1、XQ-2、XQ-3、XQ-4,其对滤纸条具有一定的降解能力,经16S rDNA鉴定,4株菌株分别为大肠埃希菌（Escherichia coli）、黏质沙雷菌（Serratia marcescens）、雷氏普罗威登斯菌（Providencia rettgeri）和费格森埃希菌（Escherichia fergusonii）。

Isolation and Screening of Cellulose-degrading Bacteria from the Manure of Beef Cattle

This study aimed to obtain the bacterial strains that could effectively degrade the cellulose in beef cattle manure. The cellulose-degrading bacteria were isolated from cattle feces and their natural compost samples by using sodium carboxymethyl cellulose as carbon source. Subsequently, the isolated strains were morphologically and molecularly identified. The cellulose-Congo red medium and filter paper degradation test were used to further assess the cellulose-degrading ability of the isolates. The results showed that a total of 32 cellulose-degrading isolates were obtained, and 4 of them （designated as XQ-1, XQ-2, XQ-3 and XQ-4, respectively） had hydrolyzed circle in Congo red medium and had a certain ability to degrade the filter paper. The 16S rDNA sequencing identification demonstrated that the 4 strains were Escherichia coli, Serratia marcescens, Providencia rettgeri and Escherichia fergusonii, respectively.