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

Abstract

An obligately anaerobic, Gram-stain-negative, non-spore-forming and non-motile rod (strain LPYR103-Pre^T) was isolated from a two-phase methane fermentation system. Using 16S rRNA gene sequence-based phylogenetic analysis, strain LPYR103-Pre^T was classified in the genus Segatella. The 16S rRNA gene sequence similarity, average nucleotide identity and digital DNA-DNA hybridization between strain LPYR103-Pre^T and its phylogenetically nearest species - Segatella cerevisiae JCM 30867^T - were 94.4, 77.9 and 23.4%, respectively. The genome size of strain LPYR103-Pre^T was 3 326 733 bp, and its genomic DNA G+C content was 44.05%. The most abundant cellular fatty acid was anteiso-C_15 : 0. The growth of strain LPYR103-Pre^T 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-Pre^T 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-Pre^T is the first described pectinophile belonging to this genus. Strain LPYR103-Pre^T 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-Pre^T and related species, the name Segatella asaccharophila sp. nov. is proposed to accommodate strain LPYR103-Pre^T (= NRIC 0997^T = JCM 37351^T=DSM 118531^T = KCTC 25923^T).