一株耐铀及伴生重金属纤维素降解菌株的分离鉴定

筛选出耐受一定浓度铀及其伴生重金属胁迫的纤维素降解菌株，以期达到重金属富集植物体减容减重的目的。通过重金属浓度梯度摇瓶筛选和羧甲基纤维素(CMC-Na)水解圈等方法筛选出一株有较强重金属抗性的纤维素降解菌株C1。经过形态学，菌株培养特征，16S rDNA序列和gyrB基因序列系统发育树对分离菌株进行鉴定和分析，鉴定为革兰氏阳性地衣芽孢杆菌(Bacillus licheniformis)。菌株C1的羧甲基纤维素酶活(CMCA)在第4天最高为99.16 U/mL；滤纸酶活(FPA)在第3天达到最高为85.89 U/mL；在10天时秸秆失重率为33.10%。筛得一株耐受一定浓度铀及伴生重金属胁迫的纤维素降解菌C1，对处置富集重金属植物体具有一定的指导意义。

Isolation and Identification of a Cellulose-degradation Bacterial Strain C1 with Uranium and Associated Heavy Metals Resistance

The study aims to screen out cellulose degradation bacteria with a certain concentration of uranium and associated heavy metal stress, thus to achieve the capacity and weight reduction in heavy metal enrichment plants. The celluloytic microbes bacterium C1 was screened through the heavy metal concentration gradient shaker and carboxymethyl cellulose hydrolysis circle. With the help of the phenotypical, cultural characteristics, phylogenetic tree based on 16S rDNA sequence and gyrB sequence, C1 was identified as Bacillus licheniformis, with gram positive. The highest CMCase activity secreted by C1 was 99.16 U/mL on the fourth day, the highest Fpase activity was 85.89 U/mL on the third day. On the tenth day, the weight loss percentage of straw was 33.10%. Screening out the celluloytic microbes bacterium C1 with a certain concentration of uranium and associated heavy metal stress has certain guiding significance to disposal of heavy metal enrichment plant.