Loktanella hongkongensis sp. nov., a novel member of the α-Proteobacteria originating from marine biofilms in Hong Kong waters

Abstract

A Gram-negative, non-motile, non-spore-forming, short rod-shaped bacterium (UST950701-009PT) was isolated from a marine biofilm in Hong Kong waters. Colonies are pink in colour, convex with a smooth surface and entire edge. Brown diffusible pigment is produced. Whitish colonies, with otherwise identical morphology, emerge from every culture upon ageing. The white colonies can be maintained as separate cultures (UST950701-009W) without turning pink. UST950701-009PT and UST950701-009W have identical 16S rRNA gene sequences and similar G+C (65·9–66·2 mol%) and fatty acid (86·22–88·52 % 18 : 1ω7c) contents. Phylogenetic analysis of the 16S rRNA gene sequence places UST950701-009PT within the Rhodobacter group of the α-subclass of the Proteobacteria. The nearest neighbours belong to the genus Loktanella, with similarity values ranging from 94·5 to 95·5 %. Data on G+C and fatty acid contents support the affiliation to the genus Loktanella. UST950701-009PT and -009W are heterotrophic, strictly aerobic and require NaCl for growth (2·0–14·0 %). Both grow in pH 5·0–10·0 and at 8–44 °C. Both are positive in oxidase, catalase and β-galactosidase tests, but they differ in the pattern of carbohydrate oxidation and assimilation. Molecular evidence together with phenotypic characteristics shows that UST950701-009PT constitutes a novel species within the genus Loktanella. The name Loktanella hongkongensis sp. nov. is proposed; the type strain is UST950701-009PT (=NRRL B-41039T=JCM 12479T) and a morphovar is UST950701-009W (=NRRL B-41040=JCM 12480).

Loktanella sediminilitoris sp. nov., isolated from tidal flat sediment

“…nov. is proposed. The type strain is D1-W3 T (5KCTC 32383 T 5CECT 8284 T ).The genus Loktanella, a member of the class Alphaproteobacteria, was created by Van Trappen et al (2004) (Van Trappen et al, 2004;Lau et al, 2004; Ivanova et al, 2005; Weon et al, 2006;Yoon et al, 2007;Hosoya & Yokota, 2007;Moon et al, 2010;Lee, 2012). In this study, we describe a Loktanella-like bacterial strain, designated D1-W3 T , which was isolated from a tidal flat in the South Sea, South Korea.…”

Loktanella litorea sp. nov., isolated from seawater

“…As of the time of writing, seven additional species of the genus Loktanella with validly published names, Loktanella hongkongensis (Lau et al, 2004), Loktanella agnita and Loktanella rosea (Ivanova et al, 2005), Loktanella koreensis (Weon et al, 2006), Loktanella maricola (Yoon et al, 2007), Loktanella atrilutea (Hosoya & Yokota, 2007) and Loktanella pyoseonensis (Moon et al, 2010), have been described. Members of the genus Loktanella have been isolated from Antarctic lakes, marine biofilms, sea sands, seawater and marine sediment (Van Trappen et al, 2004;Lau et al, 2004;Ivanova et al, 2005;Weon et al, 2006;Yoon et al, 2007;Hosoya & Yokota, 2007;Moon et al, 2010). In this study, we describe a bacterial strain resembling members of the genus Loktanella, designated DPG-5 T , which was isolated from seawater of the South Sea, Korea.…”

“…Strain DPG-5 T was distinguishable from the type strains of the all of the other species of the genus Loktanella, as well as the three most closely phylogenetically related species, by differences in phenotypic characteristics; including motility, colony colour, nitrate reduction, utilization of substrates, acid production from substrates, susceptibility to antibiotics, enzyme activities and DNA G+C contents (Table 1; Van Trappen et al, 2004;Lau et al, 2004;Ivanova et al, 2005;Hosoya & Yokota, 2007;Moon et al, 2010). These differences, in combination with the phylogenetic 0.01…”

Thalassobius mediterraneus gen. nov., sp. nov., and reclassification of Ruegeria gelatinovorans as Thalassobius gelatinovorus comb. nov.

“…Novel taxa are continuously arising within this group. Thus, since that review of names, 16 proposals of novel species and nine new genera of a-3 Proteobacteria have been published in the International Journal of Systematic and Evolutionary Microbiology (Abraham et al, 2004;Adachi et al, 2004;Cho & Giovannoni, 2004;Lau et al, 2004;Lee et al, 2004;Martínez-Cánovas et al, 2004;Shieh et al, 2004;Van Trappen et al, 2004;Wagner-Döbler et al, 2004;Labrenz et al, 2005;Macián et al, 2005a, b;Pujalte et al, 2005) and a few others are currently in press. Such a concentration of papers and independent studies on the same bacterial group implies that exhaustive care has to be taken with the criteria for proposing novel taxa and their arrangement into higher rank units.…”