Description of Gemmobacter fontiphilus sp. nov., isolated from a freshwater spring, reclassification of

Catellibacterium nectariphilum

as Gemmobacter nectariphilus comb. nov.,

Catellibacterium changlense

as Gemmobacter changlensis comb. nov.,

Catellibacterium aquatile

as Gemmobacter aquaticus nom. nov.,

Catellibacterium caeni

as Gemmobacter caeni comb. nov.,

Catellibacterium nanjingense

as Gemmobacter nanjingensis comb. nov., and emended description of the genus

Gemmobacter

and of

Gemmobacter aquatilis
Authors: Chen Wen-Ming , Cho Nian-Tsz , Huang Wei-Cheng , Young Chiu-Chung , Sheu Shih-Yi 
Published: April 2012

A light-yellow-pigmented bacterial strain designated JS43T was isolated from a freshwater spring in Taiwan and was characterized using a polyphasic taxonomic approach. Cells of strain JS43T were Gram-negative-staining, facultatively anaerobic, rod-shaped, non-motile and non-spore-forming. Growth occurred at 10–30 °C (optimum, 25 °C), at pH 7.0–10.0 (optimum, pH 7.0–8.0) and with 0–0.5 % (w/v) NaCl (optimum, 0 %). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain JS43T was a member of the family

Rhodobacteraceae

of the class

Alphaproteobacteria

. Sequence similarities to type strains of the genera

Gemmobacter

and

Catellibacterium

were between 94.6 and 98.1 %. The highest sequence similarity was found with

Gemmobacter aquatilis

DSM 3857T. Strain JS43T contained C18 : 1ω7c as the predominant fatty acid (74.4 %). The major isoprenoid quinone was Q-10 and the DNA G+C content was 69.3 mol%. The polar lipid profile consisted of a mixture of phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, two uncharacterized aminolipids and three uncharacterized phospholipids. The DNA–DNA relatedness values of strain JS43T with respect to the phylogenetically related

Gemmobacter aquatilis

DSM 3857T,

Catellibacterium aquatile

A1-9T and

Catellibacterium caeni

DCA-1T were less than 70 %. The taxonomic relationship between members of the genera

Gemmobacter

and

Catellibacterium

was clarified by means of a direct experimental comparison. Based on phylogenetic, chemotaxonomic and phenotypic data, we propose that all species currently classified in the genus

Catellibacterium

should be transferred to the genus

Gemmobacter

. The following new combinations are proposed: Catellibacterium nectariphilum is reclassified as Gemmobacter nectariphilus comb. nov. (type strain, AST4T = DSM 15620T = JCM 11959T = NBRC 100046T), Catellibacterium changlense as Gemmobacter changlensis comb. nov. (type strain, JA139T = CCUG 53722T = DSM 18774T = JCM 14338T), Catellibacterium aquatile as Gemmobacter aquaticus nom. nov. (type strain, A1-9T = CGMCC 1.7029T = NBRC 104254T), Catellibacterium caeni as Gemmobacter caeni comb. nov. (type strain, DCA-1T = CGMCC 1.7745T = DSM 21823T) and Catellibacterium nanjingense as Gemmobacter nanjingensis comb. nov. (type strain, Y12T = CCTCC AB 2010218T = KCTC 23298T). Emended descriptions of the genus Gemmobacter and of Gemmobacter aquatilis are also presented. Strain JS43T could be distinguished from recognized species of the genera

Gemmobacter

and

Catellibacterium

. It is suggested, on the basis of genotypic and phenotypic characteristics, that strain JS43T ( = BCRC 80082T = LMG 25376T) represents a novel species for which the name Gemmobacter fontiphilus is proposed.