Isolation and Characterization of an Efficient Cellulose-decomposing Strain YN1
纤维素高效降解菌YN1的筛选及其降解特性

To obtain cellulose-decomposing strains, and to use them for decomposition of rice straw and rice hull. A cellulose-decomposing strain YN1 was isolated from cattle and sheep feces compost. Strain YN1 was identified by morphologic and phylogenetic analysis. Moreover, we performed the liquid and solid fermentation of YN1, and the degrading test of cellulose. In addition, scan electron microscope was used to observe the fixed propagation of YN1 on the cellulose and cellulose degradation. The morphologic and ITS gene sequence analysis suggested that YN1 was Aspergillus sp.. Through liquid fermentation, endoglucanases, exoglucanases, beta-glucosidases and the total cellulase activities reached to maximum at the 3th day, and they were 95.7, 14.6, 20.5 and 26.6 U/mL respectively. Though solid fermentation, the 4 kinds of cellulase activities reached to maximum at the 5th day, and they were 1192.2, 100.6, 136.9 and 210.7 U/g respectively. In the degrading experiment, YN1 could degrade 41.87% of rice straw, 31.59% of rice hull in weight in 7 days respectively. The remarkable phenomenon that YN1 degrading crude cellulose could be observed by scan electron microscope. YN1 showed value of practical applications in rice straw and rice hull decomposition.