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Metabolic flexibility of enigmatic SAR 324 revealed through metagenomics and metatranscriptomics
Author(s) -
Sheik Cody S.,
Jain Sunit,
Dick Gregory J.
Publication year - 2014
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/1462-2920.12165
Subject(s) - biology , metagenomics , sulfur , formate dehydrogenase , metabolism , biochemistry , bacteria , gene , formate , genetics , chemistry , organic chemistry , catalysis
Summary Chemolithotrophy is a pervasive metabolic lifestyle for microorganisms in the dark ocean. The SAR 324 group of D eltaproteobacteria is ubiquitous in the ocean and has been implicated in sulfur oxidation and carbon fixation, but also contains genomic signatures of C 1 utilization and heterotrophy. Here, we reconstructed the metagenome and metatranscriptome of a population of SAR 324 from a hydrothermal plume and surrounding waters in the deep G ulf of C alifornia to gain insight into the genetic capability and transcriptional dynamics of this enigmatic group. SAR 324's metabolism is signified by genes that encode a novel particulate hydrocarbon monooxygenase ( pHMO ), degradation pathways for corresponding alcohols and short‐chain fatty acids, dissimilatory sulfur oxidation, formate dehydrogenase ( FDH ) and a nitrite reductase ( NirK ). Transcripts of the pHMO , NirK , FDH and transporters for exogenous carbon and amino acid uptake were highly abundant in plume waters. Sulfur oxidation genes were also abundant in the plume metatranscriptome, indicating SAR 324 may also utilize reduced sulfur species in hydrothermal fluids. These results suggest that aspects of SAR 324's versatile metabolism (lithotrophy, heterotrophy and alkane oxidation) operate simultaneously, and may explain SAR 324's ubiquity in the deep G ulf of C alifornia and in the global marine biosphere.