Segatella asaccharophila sp. nov., an anaerobic pectinophile isolated from a two-phase methane fermentation system

Int J Syst Evol Microbiol. 2024 Dec;74(12). doi: 10.1099/ijsem.0.006606.

Abstract

An obligately anaerobic, Gram-stain-negative, non-spore-forming and non-motile rod (strain LPYR103-PreT) was isolated from a two-phase methane fermentation system. Using 16S rRNA gene sequence-based phylogenetic analysis, strain LPYR103-PreT was classified in the genus Segatella. The 16S rRNA gene sequence similarity, average nucleotide identity and digital DNA-DNA hybridization between strain LPYR103-PreT and its phylogenetically nearest species - Segatella cerevisiae JCM 30867T - were 94.4, 77.9 and 23.4%, respectively. The genome size of strain LPYR103-PreT was 3 326 733 bp, and its genomic DNA G+C content was 44.05%. The most abundant cellular fatty acid was anteiso-C15 : 0. The growth of strain LPYR103-PreT was stimulated by the addition of pectin, d-galacturonate and d-glucuronate; in contrast, the strain exhibited poor growth in the presence of common sugars, such as glucose. Therefore, strain LPYR103-PreT was classified as a pectinophile - a bacterium that shows a preference for pectin and a few related compounds as substrates. Glucose is degraded by type strains of 12 species belonging to the genus Segatella; thus, strain LPYR103-PreT is the first described pectinophile belonging to this genus. Strain LPYR103-PreT produced succinate and acetate as its major metabolic end products. Based on the differences in the phylogenetic, genomic, physiological and chemotaxonomic characteristics of strain LPYR103-PreT and related species, the name Segatella asaccharophila sp. nov. is proposed to accommodate strain LPYR103-PreT (= NRIC 0997T = JCM 37351T=DSM 118531T = KCTC 25923T).

Keywords: Segatella; asaccharolytic; pectin; pectinophile; succinate.

MeSH terms

  • Anaerobiosis
  • Bacterial Typing Techniques*
  • Base Composition*
  • DNA, Bacterial* / genetics
  • Fatty Acids* / metabolism
  • Fermentation*
  • Methane* / metabolism
  • Nucleic Acid Hybridization*
  • Pectins* / metabolism
  • Phylogeny*
  • RNA, Ribosomal, 16S* / genetics
  • Sequence Analysis, DNA*

Substances

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