The Study On Microbial Diversity From Glacier And Permafrost Of Tibetan Plateau

Glacier and frozen soil(permafrost) are the special complex ecosystems.It should be considered as a stabilizing factor for sustaining for organisms and biological macromolecular (DNA,RNA and proteins) due to its property of low temperature and scant nutrition.These circumstance provide us "live fossil" on evolution of life and environment on earth.Then the glacier and frozen soil ,therefore,becomes the nature huge repositories of viable microorganisms.The study on microbial ecology of glacier and permafrost have important implication on the reconstruction of paleoclimate and paleoenvironments;lead to the establishment of bio-indicator of gradual and rapid climate change,and other physical phenomena;the research of the evolution of life and biological clock;search for biotechnologically potential cells and their metabolic end-products.In this study,the bacteria were recovered from Muztag Ata ice cores from the Qinghai-Tibet Plateau by cultivation and cultivation independent methods, we studied the microbial diversity and observed at four of these bacterial form and characteristic of physiology. We clone the CSP gene by designed and synthesized the undivided pimer because Muzt-D84 has ability to adapt low temperature commendably;we are not recovere the bacteria from permafrost by cultivation but extract the DNA directly from Qinghai-Tibet Plateau permafrost by molecular biology method ,then we established the clone library of the 16S r RNA.The main studies and results were reported as following:1. Study on the bacteria recovered from Muztag ice core by cultivation and cultivation independent method, The isolated bacteria ranged from <1 to 127 cfu/ml;Among the total amount of isolated strains,only 11 % were psychrophiles although the majority (82%) was pschrotolerants.2. Establishing DNA library and we found the superiority bacterium was actinomyces.The bacteria cultivation and cultivation independent was a little of microorganism in environment.Most of these bacteria cultivate hardly oruncultivated.So we extract DNA from permafrost directly from the Qinghai-Tibet Plateau aimed at the microbial totle DNA in environment.And we obtained its 16S rRNA sequences 15OObp in length by designed and synthesized the bacteria undivided pimer.These results helped for us establishing DNA library.The result on sequences revealed that the phylotypes were curtobacterium and shigella.Belong to high-G+C gram-positive (HGC) and y -Proteobacteria respectively.3. The observe on the characteristic of colony which we picked out randomly showed that the colony colour was yellow in Muzt-G32, colour of Muzt-D81 was light-brown, the colony colour of Muzt-D7 was golden and the colour of Muzt-D84 was yellowish,we find all of these bacteria can produce pigment or yellow colour;Morphological properties of these bacteria isolates from Muztag Ata ice were characterized by positive gram and rod shape of bacteria. The observation on the temperature sensitive are different in Muzt-D84 and Muzt-D7, Muzt-D84 bacteria grows faster than Muzt-D7 and it grows wider-ranging at -2-4 5 °C;According to the growing ability difference in different temperature,we find that Muzt-G32 belongs to psychrotrophic bacteria, Muzt-D81 belongs to psychrophile bacteria, Muzt-D84 and Muzt-D7 belong to thermophile bacteria.4. By extract of DNA from the bacteria cultivate from Muztag Ata ice cores and analyze their 16S rRNA sequences,we achieve the bacteria phylogenetic tree.Based on their 16S rRNA sequences, Muzt-D7 belongs to Brachybacterium;Muzt-G32 belongs to Microbacteriun;Muzt-D81 belongs to Cryobacterium. these bacteria belongs to HGC;Muzt-D84 belongs to LGC different with others.we can also find that the isolates had 16S rRNA sequences similar to the bacteria isolates from other cold circumstance.5. We achieved CSP (Cold shock protein) gene clon objected with Muzt-D84 by designed and synthesized the cold shock protein primer.Compared with the homologous similar sequences indicated that this gene is the part of CSP and 171bp in length.