Nocardioides daphniae sp. nov., isolated from Daphnia cucullata (Crustacea: Cladocera)

Abstract

A Gram-positive, rod-shaped or coccoid, yellow-pigmented bacterial strain, D287T, was isolated from the water flea Daphnia cucullata (Crustacea: Cladocera) collected from Lake Balaton in Hungary. Phylogenetic analysis on the basis of 16S rRNA gene sequence comparisons revealed that the strain represented a distinct lineage within the cluster of the genera Nocardioides and Marmoricola. The following characteristics were consistent with the affiliation of strain D287T to the genus Nocardioides: peptidoglycan based on ll-2,6-diaminopimelic acid, MK-8(H4) as the major menaquinone, iso-C16 : 0 as the predominant cellular fatty acid, the presence of phosphatidylglycerol and diphosphatidylglycerol and a DNA G+C content of 69.9 mol%. Owing to characteristic differences in physiological traits and levels of 16S rRNA gene sequence similarity to its phylogenetically closest neighbours that were below 97 %, strain D287T is considered to represent a novel species of the genus Nocardioides, for which the name Nocardioides daphniae sp. nov. is proposed. The type strain is D287T (=DSM 18664T=CCM 7403T).