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

Thermophilic (strain GOMI-1 T ) and mesophilic (strain KOME-1 T ) 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-1 T was 0.2–0.4 μm and that of strain KOME-1 T was 0.4–0.6 μm. Strain GOMI-1 T 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-1 T 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-1 T was able to grow with a number of carbohydrates in the presence of yeast extract. In yeast extract-containing medium, strain KOME-1 T could utilize proteins and a limited range of sugars for growth. The G+C contents of the DNA of strains GOMI-1 T and KOME-1 T were respectively 54.7 and 57.6 mol%. Major fatty acids of strain GOMI-1 T were C 16 : 0 , C 14 : 0 and iso-C 15 : 0 , whereas those of strain KOME-1 T were iso-C 15 : 0 , anteiso-C 15 : 0 and C 14 : 0 . Based on comparative analysis of 16S rRNA gene sequences of strains GOMI-1 T and KOME-1 T , 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-1 T and KOME-1 T . The type strains of Bellilinea caldifistulae and Longilinea arvoryzae are respectively GOMI-1 T (=JCM 13669 T =DSM 17877 T ) and KOME-1 T (=JCM 13670 T =KTCC 5380 T ).