Psychrosphaera saromensis gen. nov., sp. nov., within the family Pseudoalteromonadaceae, isolated from Lake Saroma, Japan

Abstract

Three Gram-negative, motile, coccoid- and ellipsoidal-shaped, non-pigmented, chemoheterotrophic bacteria, designated strains SA4-31, SA4-46 and SA4-48^T, were isolated from Lake Saroma in Japan and subjected to a polyphasic taxonomical study. 16S rRNA gene sequence analysis revealed that the novel isolates could be affiliated to the family Pseudoalteromonadaceae of the order Alteromonadales. The strains shared approximately 99.7-100% sequence similarity with each other and showed 89.5-93.2% similarity with members of the family Pseudoalteromonadaceae with validly published names. The DNA-DNA relatedness among the strains SA 4-31, SA 4-46 and SA 4-48^T was higher than 80%, a value that is accepted as a phylogenetic definition of one species. The DNA G+C contents of the three strains were 38.7-39.6 mol%. The major isoprenoid quinone was Q-8 and C16:0, C16:1 ω7c, C18:1 ω7c and C12:1 3OH were the major fatty acids. Based on the evidence from the polyphasic taxonomical study, it was concluded that the three strains should be classified as representing a new genus and species of the family Pseudoalteromonadaceae, for which the name Psychrosphaera saromensis gen. nov., sp. nov. (type strain SA4-48^T =NBRC 107123^T= KCTC 23240^T) is proposed.