Sphaerochaeta multiformis sp. nov., an anaerobic, psychrophilic bacterium isolated from subseafloor sediment, and emended description of the genus Sphaerochaeta

Int J Syst Evol Microbiol. 2014 Dec;64(Pt 12):4147-4154. doi: 10.1099/ijs.0.068148-0. Epub 2014 Sep 23.


An anaerobic, psychrophilic bacterium, strain MO-SPC2(T), was isolated from a methanogenic microbial community in a continuous-flow bioreactor that was established from subseafloor sediments collected from off the Shimokita Peninsula of Japan in the north-western Pacific Ocean. Cells were pleomorphic: spherical, annular, curved rod, helical and coccoid cell morphologies were observed. Motility only occurred in helical cells. Strain MO-SPC2(T) grew at 0-17 °C (optimally at 9 °C), at pH 6.0-8.0 (optimally at pH 6.8-7.2) and in 20-40 g NaCl l(-1) (optimally at 20-30 NaCl l(-1)). The strain grew chemo-organotrophically with mono-, di- and polysaccharides. The major end products of glucose fermentation were acetate, ethanol, hydrogen and carbon dioxide. The abundant polar lipids of strain MO-SPC2(T) were phosphatidylglycolipids, phospholipids and glycolipids. The major cellular fatty acids were C14 : 0, C16 : 0 and C16 : 1ω9. Isoprenoid quinones were not detected. The G+C content of the DNA was 32.3 mol%. 16S rRNA gene-based phylogenetic analysis showed that strain MO-SPC2(T) was affiliated with the genus Sphaerochaeta within the phylum Spirochaetes, and its closest relatives were Sphaerochaeta pleomorpha Grapes(T) (88.4 % sequence identity), Sphaerochaeta globosa Buddy(T) (86.7 %) and Sphaerochaeta coccoides SPN1(T) (85.4 %). Based on phenotypic characteristics and phylogenetic traits, strain MO-SPC2(T) is considered to represent a novel species of the genus Sphaerochaeta, for which the name Sphaerochaeta multiformis sp. nov. is proposed. The type strain is MO-SPC2(T) ( = JCM 17281(T) = DSM 23952(T)). An emended description of the genus Sphaerochaeta is also proposed.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Bacterial Typing Techniques
  • Base Composition
  • DNA, Bacterial / genetics
  • Fatty Acids / chemistry
  • Geologic Sediments / microbiology*
  • Japan
  • Molecular Sequence Data
  • Pacific Ocean
  • Phylogeny*
  • RNA, Ribosomal, 16S / genetics
  • Seawater / microbiology
  • Sequence Analysis, DNA
  • Spirochaetaceae / classification*
  • Spirochaetaceae / genetics
  • Spirochaetaceae / isolation & purification


  • DNA, Bacterial
  • Fatty Acids
  • RNA, Ribosomal, 16S

Associated data

  • GENBANK/AB598280