title: Molecular characterization of novel red green nonsulfur bacteria from five distinct hot spring communities in Yellowstone National Park.
abstract: We characterized and compared five geographically isolated hot springs with distinct red-layer communities in Yellowstone National Park. Individual red-layer communities were observed to thrive in temperatures ranging from 35 to 60 degrees C and at pH 7 to 9. All communities were dominated by red filamentous bacteria and contained bacteriochlorophyll a (Bchl a), suggesting that they represented novel green nonsulfur (GNS) bacteria. The in vivo absorption spectra of individual sites were different, with two sites showing unusual Bchl a protein absorption bands beyond 900 nm. We prepared and analyzed 16S rRNA libraries from all of these sites by using a combination of general bacterial primers and new GNS-specific primers described here. These studies confirmed the presence of novel GNS-like bacteria in all five communities. All GNS-like clones were most similar to Roseiflexus castenholzii, a red filamentous bacterium from Japan that also contains only Bchl a. Phylogenies constructed by using GNS-like clones from Yellowstone red-layer communities suggest the presence of a moderately diverse new "red" cluster within the GNS lineage. Within this cluster, at least two well-supported subclusters emerged: YRL-A was most similar to Roseiflexus and YRL-B appeared to be novel, containing no known isolates. While these patterns showed some site specificity, they did not correlate with observed Bchl a spectrum differences or obvious features of the habitat.
authors.affiliation: Department of Biology, Western Oregon University, Monmouth, Oregon 97361, USA. boomers@wou.edu
authors.forename: Sarah M
authors.initials: SM
authors.lastname: Boomer
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Lodge
authors.forename: Bryan E
authors.initials: BE
authors.lastname: Dutton
authors.forename: Beverly
authors.initials: B
authors.lastname: Pierson
mesh_terms: D025541:Bacteriochlorophyll A / Q000378:metabolism; D001483:Base Sequence; D019414:Chlorobi / Q000145:classification* / Q000235:genetics*; D004275:DNA, Ribosomal / Q000032:analysis; D017753:Ecosystem; D005618:Fresh Water / Q000382:microbiology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D010860:Pigments, Biological / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S; D017422:Sequence Analysis, DNA; D013696:Temperature
chemical_list: D025541:Bacteriochlorophyll A; D004275:DNA, Ribosomal; D010860:Pigments, Biological; D012336:RNA, Ribosomal, 16S