Chloroflexus aurantiacus J-10-fl

Chloroflexus_aurantiacus
Names Chloroflexus aurantiacus J-10-fl
Accession numbers NC_010175
Background The phylum Chloroflexi is an early branching anoxygenic phototroph lineage within the Bacteria. Often grouped as the green non-sulfur bacterial (GNSB) branch of the 16S rRNA tree of life, this name is misleading, as not all members are green and some use sulfide. Its members are apparently metabolically diverse and widely distributed in nature. Although these organisms generally stain Gram-negative, a lipopolysaccharide-containing outer membrane is not present and the peptidoglycan is a variant that usually contains L-ornithine as the diamino acid. Most members of the Chloroflexi exhibit gliding motility. Members of the Family Chloroflexaceae are gliding filamentous, anoxygenic phototrophs. The "green" members of this family (Chloroflexus spp., Chloronema spp., Oscillochloris spp., and Chlorothrix spp.) synthesize bacteriochlorophylls a and c and use chlorosomes as their light harvesting antennae, while the "red" members of this family (Heliothrix and Roseiflexus spp.) only synthesize bacteriochlorophyll a and thus lack chlorosomes. The phylum Chloroflexi is heterogeneous with regard to metabolic properties, exhibiting two different pathways for carbon fixation (reductive pentose phosphate (Calvin cycle) and 3-hydroxy-propionate pathways), and their photosynthetic apparatus is a hybrid between that of green sulfur bacteria and purple bacteria.C. aurantiacus has characteristics typical of both the green sulfur bacteria and the purple bacteria. Lateral gene transfer, however, has blurred the evolutionary history of photosynthetic prokaryotes. It is a thermophilic, filamentous gliding phototroph, forming massive accumulations as conspicuous mats in neutral to alkaline hot springs. It is found at higher temperatures than any other anoxygenic phototroph; its optimal growth temperature lies between 50 and 60 degrees C in laboratory cultures. It is typically found as the lower layer of a microbial mat with cyanobacteria growing in layers above it. In springs high in sulfide, however, Chloroflexus may be found alone.Chloroflexus grows primarily as a photoheterotroph and appears to consume the organic products of the autotrophic cyanobacteria in its native habitat. Some strains can grow autotrophically, however, using hydrogen or sulfide as an electron donor. The CO2 fixation mechanism, the 3-hydroxypropionate pathway, is unique among all phototrophs. Cells appear to lack ribulose bisphosphate carboxylase activity. The light-harvesting apparatus consists of chlorosomes appressed to the cell membrane. The chlorosomes are somewhat smaller that those of the green sulfur bacteria. The chlorosomes contain the accessory bacteriochlorophyll c. Light-harvesting complexes containing Bchl a similar to those of the purple bacteria are located in the cell membrane. The pheophytin-quinone type photochemical reaction centers are also similar to those of the purple bacteria. The cells, however, lack internal membranes typical of the purple bacteria (modified from http://genome.jgi-psf.org/finished_microbes/chlau/chlau.home.html). (HAMAP: CHLAA)
Taxonomy
Kingdom:Bacteria
Phylum:Chloroflexi
Class:Chloroflexi
Order:Chloroflexales
Family:Chloroflexaceae
Genus:Chloroflexus
Species:aurantiacus
Strain NA
Complete Yes
Sequencing centre (05-DEC-2007) US DOE Joint Genome Institute, 2800 Mitchell Drive B100, Walnut Creek, CA 94598-1698, USA
(21-DEC-2007) National Center for Biotechnology Information, NIH, Bethesda, MD 20894, USA
Sequencing quality Level 6: Finished
Sequencing depth NA
Sequencing method Sanger
Isolation site Hakone hot spring area in Japan
Isolation country Japan
Number of replicons 1
Gram staining properties Negative
Shape Filamentous
Mobility Yes
Flagellar presence No
Number of membranes 1
Oxygen requirements Anaerobic
Optimal temperature 52.0
Temperature range Thermophilic
Habitat Specialized
Biotic relationship Free living
Host name NA
Cell arrangement Filaments
Sporulation NA
Metabolism Carbon dioxide fixation
Energy source Photosynthetic, Phototroph
Diseases NA
Pathogenicity No