Abstract: The room temperature cellulose-degrading bacteria were screened from the forest soil of Hulunbeier city. The strains of high enzyme activity were separately mixed to construct room temperature cellulose-degrading consortia, and filter paper degradation abilities were measured, using three different substrates (avicel, CMC and D-salicin) as carbon source respectively to isolate cellulose-degrading bacteria at 25 ℃. The 16S rDNA sequence was used for identification and phylogenetic analysis of strains, and DNS method was used to determine the enzyme activity of exogenous glucanase, endogenous glucanase and β-glucanase of the isolated strains, as well as the filter paper enzyme activity of the cellulose-degrading consortia. As a result, 258 room temperature cellulose-degrading bacteria were isolated. Among them, the bacteria isolated with avicel as substrates belong to five classes, and the bacteria isolated with CMC or D-salicin as substrates belong to six classes. The first dominant class was γ-Proteobacteria, and the second dominant class was α-Proteobacteria. The first dominant genera was Pseudomonas, followed by Rhizobium, Oerskasty, Bacillus and Lelliottia. In 27 cellulose-degrading consortia, C11′3″, C32′2″ and C33′2″ had the highest filter paper enzyme activity, and the enzyme activity was 200.60, 200.05 and 208.79 U/mL, respectively, which is 6-10 times more than the filter paper enzyme activity of single strain in its consortia. The degradation rate of filter paper was 26.8%, 22% and 32.4%, respectively. In conclusion, C11′3″, C32′2″ and C33′2″ are optimal flora combination of cellulose-degrading consortia, which have higher application potential.

Key words: room temperature cellulose-degrading bacteria, degradation consortia, filter paper enzyme activity, carbon source