image: Microbial cells in marine sediment. view more
Credit: Image credit: Japan Agency for Marine-Earth Science and Technology
Analysis of sediment samples from throughout the ocean reveals that global microbial diversity in marine sediment is comparable to global microbial diversity in topsoil and seawater, according to a study. Marine sediment covers 70% of the Earth's surface, but little is known about the global patterns of microbial diversity in marine sediment. Tatsuhiko Hoshino, Hideyuki Doi, Fumio Inagaki, and colleagues analyzed 299 samples of marine sediment collected as core samples from 40 sites around the globe during 14 expeditions. The sample depths ranged from the seafloor to 678 meters below the seafloor. To accurately determine the diversity of microbial communities, the authors extracted and sequenced DNA from each frozen sample under the same laboratory conditions. The authors found that the diversity of microorganisms in marine sediment generally decreased with depth. The authors also found that the concentrations of organic carbon and presence of dissolved oxygen are key determinants of the taxonomic composition of sedimentary communities. Comparing the microbial diversity with that of topsoil and seawater revealed that each of the three biomes has different microbial communities but similar overall diversity. According to the authors, analysis of the biomes suggests that bacteria are more diverse than Archaea in the global biosphere.
ARTICLE #19-19139: "Global diversity of microbial communities in marine sediment," by Tatsuhiko Hoshino et al.
MEDIA CONTACT: Tatsuhiko Hoshino, Japan Agency for Marine-Earth Science and Technology, Kochi, JAPAN; e-mail: hoshinot@jamstec.go.jp
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Journal
Proceedings of the National Academy of Sciences