Rheinheimera tilapiae sp. nov., isolated from a freshwater culture pond

Abstract

A bacterial strain designated Ruye-90T was isolated from a freshwater tilapiine cichlid fish culture pond in Taiwan and characterized using a polyphasic taxonomic approach. Strain Ruye-90T was Gram-negative, aerobic, yellow-coloured, rod-shaped, and motile by means of a single polar flagellum. Growth occurred at 4–30 °C (optimum, 20–30 °C), at pH 7.0–9.0 (optimum, pH 8.0–9.0) and with 0–2 % NaCl (optimum, 0 %). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain Ruye-90T belonged to the genus Rheinheimera and its most closely related neighbour was Rheinheimera tangshanensis JA3-B52T with sequence similarity of 97.5 %. The major fatty acids were summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c, 41.3 %), C16 : 0 (19.3 %), C18 : 1ω7c (8.4 %) and C12 : 0 3-OH (7.0 %). The major respiratory quinone was Q-8. The DNA G+C content of the genomic DNA was 49.0 mol%. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylserine, aminolipid and two uncharacterized phospholipids. The DNA–DNA relatedness of strain Ruye-90T with respect to recognized members of the genus Rheinheimera was less than 70 %. On the basis of the genotypic, chemotaxonomic and phenotypic data, strain Ruye-90T represents a novel species in the genus Rheinheimera , for which the name Rheinheimera tilapiae sp. nov. is proposed. The type strain is Ruye-90T ( = LMG 26339T = BCRC 80263T = KCTC 23315T).