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Aerobic anoxygenic photosynthesis genes and operons in uncultured bacteria in the Delaware River
Author(s) -
Waidner Lisa A.,
Kirchman David L.
Publication year - 2005
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/j.1462-2920.2005.00883.x
Subject(s) - anoxygenic photosynthesis , biology , fosmid , operon , proteobacteria , bacteria , gammaproteobacteria , alphaproteobacteria , purple bacteria , gene , gene cluster , microbiology and biotechnology , phototroph , green sulfur bacteria , genetics , botany , metagenomics , photosynthesis , escherichia coli , 16s ribosomal rna , photosynthetic reaction centre
Summary Photosynthesis genes and operons of aerobic anoxygenic photosynthetic (AAP) bacteria have been examined in a variety of marine habitats, but genomic information about freshwater AAP bacteria is lacking. The goal of this study was to examine photosynthesis genes of AAP bacteria in the Delaware River. In a fosmid library, we found two clones bearing photosynthesis gene clusters with unique gene content and organization. Both clones contained 37 open reading frames, with most of those genes encoding known AAP bacterial proteins. The genes in one fosmid were most closely related to those of AAP bacteria in the Rhodobacter genus. The genes of the other clone were related to those of freshwater beta‐proteobacteria. Both clones contained the acs F gene, which is required for aerobic bacteriochlorophyll synthesis, suggesting that these bacteria are not anaerobes. The beta‐proteobacterial fosmid has the puf operon B‐A‐L‐M‐C and is the first example of an uncultured bacterium with this operon structure. The alpha‐3‐proteobacterial fosmid has a rare gene order (Q‐B‐A‐L‐M‐X), previously observed only in the Rhodobacter genus. Phylogenetic analyses of photosynthesis genes revealed a possible freshwater cluster of AAP beta‐proteobacteria. The data from both Delaware River clones suggest there are groups of freshwater or estuarine AAP bacteria distinct from those found in marine environments.