This Article Full Text (PDF) Other Versions of this Article: AEM.02751-07v1 74/14/4516    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Wu, L. Articles by Zhou, J. Search for Related Content PubMed PubMed Citation Articles by Wu, L. Articles by Zhou, J. Agricola Articles by Wu, L. Articles by Zhou, J.

 Previous Article  |  Next Article 

Appl. Environ. Microbiol. doi:10.1128/AEM.02751-07
Copyright (c) 2008, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.

Microarray-Based Characterization Of Microbial Community Functional Structure And Heterogeneity In Marine Sediments From The Gulf Of Mexico

Institute for Environmental Genomics and Department of Botany and Microbiology, University of Oklahoma, Norman, OK 73019; School of Oceanography, University of Washington, Seattle, Washington, 982954; Environmental Sciences Division, Oak Ridge National laboratory, Oak Ridge, TN 37831; Center for Microbial Ecology, Michigan State University, East Lansing, Michigan 48824

^* To whom correspondence should be addressed. Email: jzhou{at}ou.edu.

	Abstract

Marine sediments of coastal margins are important sites of carbon sequestration and nitrogen cycling. To determine the metabolic potential and structure of marine sediment microbial communities, two cores were collected each from the two stations (GMT at 200m and GMS at 800m) in the Gulf of Mexico, and six subsamples representing different depths were analyzed from each of these two cores using the functional gene arrays (FGAs) containing 2000 probes targeting genes involved in carbon fixation, organic carbon degradation, contaminant degradation, metal resistance, and nitrogen, sulfur, and phosphorous cycling. The geochemistry was highly variable for the sediments based on both site and depth. A total of 930 (47.1%) probes belonging to various functional gene categories showed significant hybridization with at least one of the 12 samples. The overall functional gene diversity of the samples from shallow depths was in general lower than those from deep depths at both stations. Also high microbial heterogeneity existed in these marine sediments. In general, the microbial community structure was more similar when the samples were spatially closer. The number of unique genes at GMT increased with depth, from 1.7% at 0.75 cm to 18.9% at 25 cm depth. The same trend occurred at GMS, from 1.2% at 0.25 cm to 15.2% at 16 cm. In addition, a broad diversity of geochemically important metabolic functional genes related carbon degradation, nitrification, denitrification, nitrogen fixation, sulfur reduction, phosphorus utilization, contaminant degradation and metal resistance are observed, implying that thus marine sediments could play important roles in biogeochemical cycling of carbon, nitrogen, phosphorus, sulfate and various metals. Finally, the Mantel test revealed significant positive correlations between various specific functional genes and functional processes, and canonical correspondence analysis (CCA) suggested that sediment depth, PO₄^3-, NH₄⁺, Mn(II), porosity, and Si(OH)₄ might play major roles in shaping the microbial community structure in the marine sediments.