Zunongwangia mangrovi sp. nov., isolated from mangrove (Avicennia marina) rhizosphere, and emended description of the genus Zunongwangia

A Gram-stain-negative, strictly aerobic, slightly halophilic, non-motile and rod-shaped bacterial strain, designated P2E16T, was isolated from mangrove (Avicennia marina) rhizosphere, collected at Devipattinam mangroves, Tamil Nadu, India. Strain P2E16T grew optimally at pH 7.0–8.0, at 25–28 °C and in the presence of 2–3 % (w/v) NaCl. 16S rRNA gene analysis showed that strain P2E16T was phylogenetically closely related to the genus Zunongwangia , with Zunongwangia profunda SM-A87T as the closest related type strain (98.2 % 16S rRNA gene sequence similarity) and less than 93 % 16S rRNA gene sequence similarity to all other members of the family Flavobacteriaceae . Strain P2E16T contained MK-6 as the major respiratory quinone, phosphatidylethanolamine as the predominant polar lipid and iso-C15 : 0 (17.8 %), iso-C17 : 0 3-OH (15.1 %), C15 : 0 (12.8 %), iso-C17 : 1ω9c (9.8 %), iso-C15 : 1 G (9.0 %), and summed feature 3 (comprising C16 : 1ω7c and/or iso-C15 : 0 2-OH; 7.1 %) as the major fatty acids. The DNA G+C content was 34.3 mol%. Differential phenotypic properties, together with the phylogenetic distinctiveness and low DNA–DNA relatedness demonstrated that strain P2E16T was distinct from the type strain of Zunongwangia profunda . On the basis of these presented data, strain P2E16T is considered to represent a novel species of the genus Zunongwangia , for which the name Zunongwangia mangrovi sp. nov. is proposed. The type strain is P2E16T ( = DSM 24499T = LMG 26237T = KCTC 23496T). An emended description of the genus Zunongwangia is also provided.

Characterization of Bacterial Polysaccharide Capsules and Detection in the Presence of Deliquescent Water by Atomic Force Microscopy

ABSTRACTWe detected polysaccharide capsules fromZunongwangia profundaSM-A87 with atomic force microscopy (AFM). The molecular organization of the capsules at the single-polysaccharide-chain level was reported. Furthermore, we found that with ScanAsyst mode the polysaccharide capsules could be detected even in the presence of deliquescent water covering the capsule.