The Analysis Of The Culturable Bacteria Diversity In Lichens And Screening Of Cellulose Degradation Bacterias

Lichen is a a special plant consists of fungus and algae, without the differentiation of root, stem and leaf. Known as "the pioneer plant kingdom", the symbiotic fungi are mostly ascomycetes, the minority is a basidiomycete fungi. They can absorb water and inorganic salts, and coating by algae. The symbiotic algae are mainly cyanobacteria and algae which can for photosynthesis and to product the organic. With a growing amount of evidence suggests that some lichens symbiotic system not only contains fungi and photosynthetic organisms, Also including a mount of symbiotic bacterias which provide the nutrition, nitrogen source and resist biological and abiotic stress for the lichens, Biofilm-like bacterias are widely distributed in the cortex, algal layer and medullary layer. With the in-depth study of bacteria in lichens symbiotic system, the role that the bacterias plays in lichens is becoming more and more important.This experiment was carried out with the materias collecting from 11 different places in xinjiang and 21 samples of lichen was used for the isolated culture of endophytic bacteria. The 21 samples belonging to 11 different genus, mainly includes Umbilicaria sp., Dermatocarpon sp., Peltigera sp.. We get a total of 91 bacteria strains with the method of isolated culture with the PDA medium under 20?. the 16 S r RNA sequence analysis illustrates that the 91 bacteria strains including 40 strains of Alphaproteobacteria, 19 strains of Actinobacteria, 19 strains of Gammaproteobacteria, 6 strains of Betaproteobacteria, 6 strains of Firmicutes and 1strain of Bacteroidetes. In the isolated culture bacteria, the largest proportion is Alphaproteobacteria, accounting for 44%. The Sphingomonas contain the most species,accounting for 77.5%. The Actinobacteria is followed by, containing different genus and species.A total of 35 strains of endophytic bacteria strains were isolated from 5 Peltigera sp. specimens. In the lichens of Peltigera sp., the bacterias of Proteobacteria are inthe majority, accounting for 60%. Besides, there exist some bacterias of Actinobacteria, accounting for 31.4%. There also exist some bacterias of Firmicute,accounting for 8.6%. A total of 10 strains of endophytic bacteria strains were isolated from 2 Umbilicaria sp. specimens. In the lichens of Umbilicaria sp., the bacterias of Alphaproteobacteria are in the majority, accounting for 60%, there exist some bacterias of Bacteroidetes, accounting for 10%. The bacterias of Betaproteobacteria and Actinobacteria didn,t exist in the lichens of Umbilicaria sp.. In the different lichens, there exist different distribution of bacterial community which reflects that the endophytic bacteria has a certain host specificity. The richness of species and the diversity of bacterial community of the endophytic bacteria in Peltigera sp. is higher than that of the Umbilicaria sp..The CMC-Na medium was used as the sole carbon source to screen the 91 isolated bacteria which has the ability to degrade cellulose. We get the CMC-Na degradation strains on the primary screening medium, we used the congo red dyeing to make a preliminary determine of the CMC-Na degradation strains. The DNS method was used for determining the enzyme activity of cellulose degradation enzyme. A total of24 strains were screened with higher enzyme activity for efficient cellulolytic. The bacteria strains of high enzyme activity are 0431-4, 0688-9, 0583-23, 0431-5,0200-7,the enzyme activity respectively reaching 0.803260 IU/m L, 0.743556 IU/m L,0.683852 IU/m L, 0.668237 IU/m L, 0.632874 IU/m L. The bacteria strain of 0431-4which isolated from Xanthoparmelia sp. has the highest enzyme activity, the 16 S r RNA sequence analysis results show that 0431-4 belongs to the genus of Methylobacterium.This study adopts the method of cultivation to study the diversity of the endophytic bacteria in different lichens, enriching the awareness of the bacterial diversity in lichens.The study has a positive meaning to make a further study of the position and the role of bacteria in the lichen symbiotic system, also have a meaning of studying the development and utilization of lichen resources and the bacteria activeproducts. The related research of the lichen symbiotic bacteria is expected to provide new microbial resources for field of cellulose degradation.