Bellilinea caldifistulae gen. nov., sp. nov. and Longilinea arvoryzae gen. nov., sp. nov., strictly anaerobic, filamentous bacteria of the phylum Chloroflexi isolated from methanogenic propionate-degrading consortia Yamada, Takeshi and Imachi, Hiroyuki and Ohashi, Akiyoshi and Harada, Hideki and Hanada, Satoshi and Kamagata, Yoichi and Sekiguchi, Yuji,, 57, 2299-2306 (2007), doi = https://doi.org/10.1099/ijs.0.65098-0, publicationName = Microbiology Society, issn = 1466-5026, abstract= Thermophilic (strain GOMI-1T) and mesophilic (strain KOME-1T) strains were isolated from two different cultures of propionate-degrading consortia obtained from thermophilic digester sludge and rice paddy soil, respectively. The two strains were non-spore-forming, non-motile and Gram-negative. Both strains were obligately anaerobic micro-organisms, showing multicellular filamentous morphotypes more than 100 μm in length. The cell width for strain GOMI-1T was 0.2–0.4 μm and that of strain KOME-1T was 0.4–0.6 μm. Strain GOMI-1T could grow at 45–65 °C with a pH range of 6.0–7.5 (optimum growth at 55 °C, pH 7.0). The temperature range for growth of strain KOME-1T was 30–40 °C and the pH range was pH 5.0–8.5 (optimum growth around 37 °C, pH 7.0). Yeast extract was required for growth of both strains. Strain GOMI-1T was able to grow with a number of carbohydrates in the presence of yeast extract. In yeast extract-containing medium, strain KOME-1T could utilize proteins and a limited range of sugars for growth. The G+C contents of the DNA of strains GOMI-1T and KOME-1T were respectively 54.7 and 57.6 mol%. Major fatty acids of strain GOMI-1T were C16 : 0, C14 : 0 and iso-C15 : 0, whereas those of strain KOME-1T were iso-C15 : 0, anteiso-C15 : 0 and C14 : 0. Based on comparative analysis of 16S rRNA gene sequences of strains GOMI-1T and KOME-1T, the strains were placed in different phylogenetic positions in the class Anaerolineae of the bacterial phylum Chloroflexi. Their phenotypic and genetic traits strongly supported the conclusion that the strains should be described as two independent taxa in the class Anaerolineae. Hence, we propose the names Bellilinea caldifistulae gen. nov., sp. nov., and Longilinea arvoryzae gen. nov., sp. nov., for strains GOMI-1T and KOME-1T. The type strains of Bellilinea caldifistulae and Longilinea arvoryzae are respectively GOMI-1T (=JCM 13669T =DSM 17877T) and KOME-1T (=JCM 13670T =KTCC 5380T)., language=, type=