title: Reverse dissimilatory sulfite reductase as phylogenetic marker for a subgroup of sulfur-oxidizing prokaryotes.
abstract: Sulfur-oxidizing prokaryotes (SOP) catalyse a central step in the global S-cycle and are of major functional importance for a variety of natural and engineered systems, but our knowledge on their actual diversity and environmental distribution patterns is still rather limited. In this study we developed a specific PCR assay for the detection of dsrAB that encode the reversely operating sirohaem dissimilatory sulfite reductase (rDSR) and are present in many but not all published genomes of SOP. The PCR assay was used to screen 42 strains of SOP (most without published genome sequence) representing the recognized diversity of this guild. For 13 of these strains dsrAB was detected and the respective PCR product was sequenced. Interestingly, most dsrAB-encoding SOP are capable of forming sulfur storage compounds. Phylogenetic analysis demonstrated largely congruent rDSR and 16S rRNA consensus tree topologies, indicating that lateral transfer events did not play an important role in the evolutionary history of known rDSR. Thus, this enzyme represents a suitable phylogenetic marker for diversity analyses of sulfur storage compound-exploiting SOP in the environment. The potential of this new functional gene approach was demonstrated by comparative sequence analyses of all dsrAB present in published metagenomes and by applying it for a SOP census in selected marine worms and an alkaline lake sediment.
authors.affiliation: Department of Microbial Ecology, Universität Wein, Wein, Austria. loy@microbial-ecology.net
authors.forename: Alexander
authors.initials: A
authors.lastname: Loy
authors.forename: Stephan
authors.initials: S
authors.lastname: Duller
authors.forename: Christian
authors.initials: C
authors.lastname: Baranyi
authors.forename: Marc
authors.initials: M
authors.lastname: Mussmann
authors.forename: Jörg
authors.initials: J
authors.lastname: Ott
authors.forename: Itai
authors.initials: I
authors.lastname: Sharon
authors.forename: Oded
authors.initials: O
authors.lastname: Béjà
authors.forename: Denis
authors.initials: D
authors.lastname: Le Paslier
authors.forename: Christiane
authors.initials: C
authors.lastname: Dahl
authors.forename: Michael
authors.initials: M
authors.lastname: Wagner
mesh_terms: D001105:Archaea / Q000145:classification* / Q000201:enzymology* / Q000235:genetics; D001419:Bacteria / Q000145:classification* / Q000201:enzymology* / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D050885:Hydrogensulfite Reductase / Q000235:genetics*; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000379:methods*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013457:Sulfur Compounds / Q000378:metabolism*
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D013457:Sulfur Compounds; D050885:Hydrogensulfite Reductase