Diversity of culturable bacteria in the typical frozen soil areas in China

Abstract:

Abstract:［Objective］The diversity of culturable bacteria in the six frozen soils from High-latitude area and High-altitude area were analyzed by using culture-dependent approaches．［Methods］Three solidified media were used to isolate culturable bacteria． Bacterial 16S rRNA genes of the isolates were PCR amplified using bacteria-universal primers，and then were sequenced． The resulting bacterial 16S rRNA gene sequences were subjected to phylogenetic analysis．［Results］The abundance of culturable bacteria ranged from 4.70×103 to 2.57×105 colony forming units (CFU) per gram of soils (dry weight)． A total of 144 bacterial strains were obtained． The bacterial isolates from the High-latitude area were affiliated with three phyla (Firmicutes，Gammaproteobacteria，and Betaproteobacteria) with Pseudomonas，Bacillus，and Paenibacillus strains being dominant． The bacterial isolates from High-altitude area could be grouped into three different phyla (Gammaproteobacteria，Firmicutes，and Bacteroidetes) with Pseudomonas strains be dominant． ［Conclusion］The culturable bacteria are abundant and diverse in the frozen soils of High-latitude and High-altitude areas． The results also showed that the culturable bacterial community structure varied among different research areas．Our data have implications for a better understanding of culturable bacterial community in the frozen soils in China．

Key words:Keywords: frozen soils，the Greater Khingan Range，Tibetan Plateau，diversity of culturable bacteria，16S rRNA gene