Journal
FEMS MICROBIOLOGY ECOLOGY
Volume 94, Issue 4, Pages -Publisher
OXFORD UNIV PRESS
DOI: 10.1093/femsec/fiy023
Keywords
psychrophile; psychrotroph; cold adaptation; subzero; permafrost; amino acid composition
Categories
Funding
- Natural Sciences and Engineering Research Council (NSERC)
- CREATE Canadian Astrobiology Training Program(CATP)
- NSERC Canadian Graduate Scholarship
- NSERC Discover Grant Program
- Northern Research Supplement grant
- Polar Continental Shelf Project grant
- Office of Science of the U. S. Department of Energy [DE-AC02-05CH11231]
Ask authors/readers for more resources
Permafrost accounts for 27% of all soil ecosystems and harbors diverse microbial communities. Our understanding of microorganisms in permafrost, their activities and adaptations, remains limited. Using five subzero-growing (cryophilic) permafrost bacteria, we examined features of cold adaptation through comparative genomic analyses with mesophilic relatives. The cryophiles possess genes associated with cold adaptation, including cold shock proteins, RNA helicases, and oxidative stress and carotenoid synthesis enzymes. Higher abundances of genes associated with compatible solutes were observed, important for osmoregulation in permafrost brine veins. Most cryophiles in our study have higher transposase copy numbers than mesophiles. We investigated amino acid (AA) modifications in the cryophiles favoring increased protein flexibility at cold temperatures. Although overall there were few differences with the mesophiles, we found evidence of cold adaptation, with significant differences in proline, serine, glycine and aromaticity, in several cryophiles. The use of cold/hot AA ratios of >1, used in previous studies to indicate cold adaptation, was found to be inadequate on its own. Comparing the average of all cryophiles to all mesophiles, we found that overall cryophiles had a higher ratio of cold adapted proteins for serine (more serine), and to a lesser extent, proline and acidic residues (fewer prolines/acidic residues).
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available