title: Anaerolinea thermophila gen. nov., sp. nov. and Caldilinea aerophila gen. nov., sp. nov., novel filamentous thermophiles that represent a previously uncultured lineage of the domain Bacteria at the subphylum level.
abstract: Two thermophilic, Gram-negative, non-spore-forming, multicellular filamentous micro-organisms were isolated from thermophilic granular sludge in an upflow anaerobic sludge blanket reactor treating fried soybean-curd manufacturing waste water (strain UNI-1(T)) and from a hot spring sulfur-turf in Japan (strain STL-6-O1(T)). The filaments were longer than 100 microm and of 0.2-0.3 microm (strain UNI-1(T)) or 0.7-0.8 microm (strain STL-6-O1(T)) in width. Strain UNI-1(T) was a strictly anaerobic organism. The optimum temperature for growth was around 55 degrees C; growth occurred in the range 50-60 degrees C. The optimum pH for growth was around 7.0; growth occurred in the range pH 6.0-8.0. Strain STL-6-O1(T) was a facultatively aerobic bacterium. The optimum temperature for growth was around 55 degrees C; growth occurred in the range 37-65 degrees C. The optimum pH for growth was around 7.5-8.0; growth occurred in the range pH 7.0-9.0. The two organisms grew chemo-organotrophically on a number of carbohydrates and amino acids in the presence of yeast extract. The G+C content of the DNA of strains UNI-1(T) and STL-6-O1(T) was 54.5 and 59.0 mol%, respectively. Major cellular fatty acids for strain UNI-1(T) were C(16 : 0), C(15 : 0), C(14 : 0) and C(18 : 0), whereas those for strain STL-6-O1(T) were C(18 : 0), C(16 : 0), C(17 : 0) and iso-C(17 : 0). MK-10 was the major quinone from aerobically grown STL-6-O1(T) cells. Phylogenetic analyses based on 16S rDNA sequences revealed that both strains belong to an uncultured, previously recognized clone lineage of the phylum Chloroflexi (formerly known as green non-sulfur bacteria). These phenotypic and genetic properties suggested that each strain should be classified into a new independent genus; hence, the names Anaerolinea thermophila and Caldilinea aerophila are proposed for strains UNI-1(T) (=JCM 11387(T)=DSM 14523(T)) and STL-6-O1(T)(=JCM 11388(T)=DSM 14525(T)), respectively. These strains represent the type and sole species of the genera Anaerolinea and Caldilinea, respectively.
authors.affiliation: Institute for Biological Resources and Functions, National Institute of Advanced Industrial Science and Technology (AIST), Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Sekiguchi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yamada
authors.forename: Satoshi
authors.initials: S
authors.lastname: Hanada
authors.forename: Akiyoshi
authors.initials: A
authors.lastname: Ohashi
authors.forename: Hideki
authors.initials: H
authors.lastname: Harada
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Kamagata
mesh_terms: D001419:Bacteria / Q000145:classification; D041862:Chloroflexi / Q000145:classification* / Q000235:genetics* / Q000254:growth & development / Q000648:ultrastructure; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D010802:Phylogeny