Isolation, Identification Of Different Temperature Type Cellulolytic Micobes From Zoige Wetland And The Effect Of Co-Fermentation

Zoige wetland is the primitive wetland of our country, and it is kept very well. Because of it's special geological condition, it has allowed the establishment of some special microorganisms. The resources of the animals and plants have been extensively investigated. But the microorganisms in this area have not been studied. The marsh vegetation offered abundant organic matter for Zoige wetland, and a large amount of cellulose materials were in the wetland soil, and the content of coarse fibre was 37.78% . There are important meanings to the development of the microbes resources by carry on research to the cellulolytic microbes of Zoige wetland .The results of this study are as followed:Three soil samples were collected from Zoige wetland. The result showed that Zoige wetland contains a large amount of microorganisms, the quantity of the fungi was 55-146 cfu/gram, bacterium: 4.00×10⁴⁸.35×10⁶ cfu/gram, actinomyces: 46.7⁶4.3 cfu / gram.The viable numbers of bacteria were more than that of fungi and actinomyces. The distributing rule of cellulolytic microbes was: bacteria > fungi > actinomyces. Thirty-two cellulolytic microbes strains were isolated form Zoige wetland , including the bacterium, fungi and actinomyces. There were relatively more bacterium kinds, Curtobacterium sp., Bacillus sp. and Brevibacillus sp.Thirty-two cellulolytic microbes were growing in the range of temperature: 15℃ 20℃, 25℃³0℃ 40℃⁵0℃. The maderate temperature strains were the most abundant, 14 strains of bacterium,actinomyce and fungi. Twelve strains of bacteria which included were able to grow at low temperature. High temperature strains including 1 fungi and 5 bacteria were detected. Different strains had different ability of cellulose degradation. According to the growth rate and CMC enzyme activity, 14 strains were screened with stronger cellulose decomposing ability .Among 32 strains bacterial strain B₂₂ showned the strongest cellulose decomposing ability. It's average growth velocity was 1.47 cm/d, and CMC enzyme activity reached 480.5U.The optimal solid culture for producing cellulase was found out by orthogonalexperiment. The proportion of bran to straw was 3:7, (NH4) 2SO4 was 2%. The rate between material and water was 1:1 — 1 ;2.In the process of cellulose decomposition, the temperature has the tendency to rise from low to high. Co-fermentation with the strains of different temperature types can allow the full functions of the strains at different fermentation stages. Four combinations of high activity were obtained which were B3—F2—B27,B7^Fi—F2,B9^F2—Bi9,B9 F2-Ai. Their CMC enzyme activity was 3157.1 U/g, 3650.8 U/g, 3380.9 U/g, 2818.2 U/g respectively .The CMC enzyme activity reached peak at the time of 48⁷2h . The CMC enzyme activity was increased by 15% in comparison with the single strain fermentation. The experiment of loss substrate further proved that co-fermentation with different temperature type strains could significantly enhance the cellulose degradation than that of single strains. The results indicated the mutualistic association among the different temperature type strains in the process of cellulose degradation.