Aquatic Sciences Meeting, Albuquerque 2001

PC04 Microbial Diversity

Date: Tuesday, February 13, 2001

Location: Southwest Hall

Madrid, V, M, Marine Sciences Research Center, State University of New York, Stony Brook, NY 11794-5000, USA, madrid@msrc.sunysb.edu

Chistoserdov, A, Y, Marine Sciences Research Center, State University of New York, Stony Brook, NY 11794-5000, USA, andrei@notes.cc.sunysb.edu

Aller, J, Y, Marine Sciences Research Center, State University of New York, Stony Brook, NY 11794-5000, USA, jyaller@notes.cc.sunysb.edu

Aller, R, C, Marine Sciences Research Center, State University of New York, Stony Brook, USA, raller@notes.cc.sunysb.edu

COMPARATIVE PHYLOGENETIC ANALYSIS OF PROKARYOTIC COMMUNITIES FROM TWO MOBILE DELTAIC MUD SEDIMENTS

Mobile deltaic muds from off the French Guiana coast appear to be similar to those from the Gulf of Papua in that remineralization processes are net suboxic rather than sulfidogenic. 16S rDNA sequence analyses of prokaryotic communities from both locales show similar phylogenetic composition but differ in the proportion of sequences belonging to each group. Sequences most closely related to fermenters and other chemoorganotrophs belonging to the Cytophaga-Flexibacter-Bacteroides group, Planctomyces and relatives, alpha-proteobacteria, and high GC Gram-positive bacteria are present in both libraries, but dominate the FG sediment library. Delta and gamma proteobacteria potentially involved in sulfate/sulfur reduction and sulfide oxidation, respectively while present in both libraries, dominate the GP sediments. In spite of the fact that both libraries support the concept of a close coupling of S cycling to suboxic conditions, greater concentrations of labile organic C inputs to the FG sediments further promote the dominance of chemoorganothrophs over chemolithotrophs.

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Aquatic Sciences Meeting, Albuquerque 2001

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