Isolation And Screening Of Cellulose-degrading Bacteria From Minya Konka Of West Sichuan Plateau

As the main component of plant cytoderm, cellulose is the most abundant biomass reproducible resources. China is a large agricultural nation. The production of agricultural waste, including the cotton seed shell, straw, saw dust and so on, was extremely huge. Isolating and screening cellulose degrading bacteria that can efficiently utilize cellulose is crucial to improve agricultural production and conversion of cellulosic materials. This study is aimed to isolate, purify and screen out the best cellulose degrading bacteria that can efficiently degrade cellulose, and find out the best mixed fermentation of strain combination in degrading process of corn straw. The results as follows:1. Three media that Carboxyl Methyl Cellulose (CMC) was used as sole carbon source were used as isolation media, a total of 79 strains were isolated from forest soil collected from Minya Konka of West Sichuan Plateau,2. Congo Red differential medium 15 strains were screened using. Accordinng to the morphology characteristics of the stains,4 of 15 strains belong to bacteria and the rest strains belong to actinomycetes. The CMC enzyme activity of 15 strains were analyzed and calculated, isolate 112,110,174,154,146 capable of degrading cellulose with high efficiency, the CMC enzyme activity reached 78.13 U,75.05 U,71.75 U,70.65 U,65.15 U, respectively.3. The result of antagonistic relationship among all 15 strains showed no obvious antagonisim between most strains of bacteria or actinomycetes. For instance, strain 112、 146、171、174 didn’t show any antagonisim to each other. However, strain 110 exhibit antagonisim to 146,147,154 and 171.4. The corn straw was used as carbon source, the CMC enzyme activity of strain 110,116, 145,150,153,154,174 and 179 were relatively higher than other strains. The cellulose produced by fermentation of 154 after 9 days, showed a strongest enzyme activity of 48.90 U. The CMC enzyme activity of mixed fermentation of A(110、116、174) and F (A+B) were higher than the other combination that reached 47.74 U,57.03 U, respectively, and the enzyme activity of F (A+B) was higher than that fermemtation of single strain.5. Base on the 16S rDNA sequence, strain 110,116,147,154,171 and 174 were identified as Paenibacillus pabuli, Paenibacillus xylanexedens, Streptomyces rochei, Streptomyces rochei, Streptomyces hygroscopicus and Acinetobacter junii, respectively.