Diversity and distribution of alkaliphilic psychrotolerant bacteria in the Qinghai-Tibet Plateau permafrost region

Extremophiles. 2007 May;11(3):415-24. doi: 10.1007/s00792-006-0055-9. Epub 2007 Feb 16.

Abstract

The Qinghai-Tibet Plateau represents a unique permafrost environment, being a result of high elevation caused by land uplift. And the urgency was that plateau permafrost was degrading rapidly under the current predicted climatic warming scenarios. Hence, the permafrost there was sampled to recover alkaliphilic bacteria populations. The viable bacteria on modified PYGV agar were varied between 10(2) and 10(5 )CFU/g of dry soil. Forty-eight strains were gained from 18 samples. Through amplified ribosomal DNA restriction analysis (ARDRA) and phylogenetic analyses, these isolates fell into three categories: high G + C gram positive bacteria (82.3%), low G + C gram positive bacteria (7.2%), and gram negative alpha-proteobacteria (10.5%). The strains could grow at pH values ranging from 6.5 to 10.5 with optimum pH in the range of 9-9.5. Their growth temperatures were below 37 degrees C and the optima ranging from 10 to 15 degrees C. All strains grew well when NaCl concentration was below 15%. These results indicate that there are populations of nonhalophilic alkaliphilic psychrotolerant bacteria within the permafrost of the Qinhai-Tibet plateau. The abilities of many of the strains to produce extracellular protease, amylase and cellulase suggest that they might be of potential value for biotechnological exploitation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptation, Physiological*
  • Bacteria / classification
  • Bacteria / isolation & purification*
  • Base Sequence
  • Culture Media
  • DNA Primers
  • Phylogeny
  • Species Specificity

Substances

  • Culture Media
  • DNA Primers