Rheinheimera texasensis sp. nov., a halointolerant freshwater oligotroph

Abstract

A Gram-negative, rod-shaped, motile, non-spore-forming bacterium, designated strain A62-14BT, was isolated from a constant-temperature, spring-fed, freshwater lake. On the basis of the complete 16S rRNA gene sequence, strain A62-14BT was shown to belong to the class Gammaproteobacteria, being most closely related to Rheinheimera sp. HTB082 (96.2 % sequence similarity), Rheinheimera baltica (95.01 %), Rheinheimera pacifica (96.35 %), Rheinheimera perlucida and Alishewanella fetalis (95.9 %). The major fatty acids (C16 : 1 ω7c, 38.56 %; C16 : 0, 19.04 %; C12 : 0 3-OH, 12.83 %; C18 : 1 ω7c, 7.70 %) and the motility of strain A62-14BT support its affiliation to the genus Rheinheimera. The salt intolerance of strain A62-14BT, together with the results of other physiological and biochemical tests, allowed the differentiation of this strain from the three species of the genus Rheinheimera with validly published names. Therefore strain A62-14BT represents a novel species of the genus Rheinheimera, for which the name Rheinheimera texasensis sp. nov. is proposed. The type strain is A62-14BT (=ATCC BAA-1235T=DSM 17496T). The description of the genus Rheinheimera is emended to reflect the halointolerance and freshwater origin of strain A62-14BT.