Screening of high efficient cellulose-decomposing microorganisms

In this study, liquid enrich culture using filter paper and sodium carboxymethyl cellulose as sole carbon sources was prepared and ten gram of soil samples collected from different sites was inoculated and incubated, respectively. By using continuous enrich culturing process, three high efficiency cellulose-degrading microbial strains JSB1, JSA1 and JSF1 were screened and their phylogenic position were determined. The results of 16S rDNA sequencing showed that bacterial strain JSB1 belonged to Bacillus sp. and actinomycete strain JSA1 belonged to Streptomyces sp. respectively. Based on the morphology and ITS fragment sequence, fungal strain JSF1 was determined as Trichoderma longibrachiatum. Confrontation tests revealed that there was no antagonistic phenomenon among these three strains. The compound inoculants consisted of those three strains at ratio 1: 1: 1 and its cellulose activity reached to 300U/ml. Adding 5% of compound inoculants and 2% of urea as nitrogen source with rice straw, the fermentation was done. The results showed that after 15 days' fermentation, the weight loss rate of rice straw achieved 53.91% and the degrading rates of cellulose, hemicellulose and lignin were 37.55%, 56.65% and 14.78% respectively. These results suggested that these strains can be used as straw-degrading strains.