Transfer of Sphingorhabdus marina, Sphingorhabdus litoris, Sphingorhabdus flavimaris and Sphingorhabdus pacifica corrig. into the novel genus Parasphingorhabdus gen. nov. and Sphingopyxis baekryungensis into the novel genus Novosphingopyxis gen. nov. within the family Sphingomonadaceae

Abstract

During a phylogenetic analysis of Sphingorhabdus and its closely related genera in the family Sphingomonadaceae , we found that the genus Sphingorhabdus and the species Sphingopyxis baekryungensis might not be properly assigned in the taxonomy. Phylogenetic, phenotypic and chemotaxonomic characterizations clearly showed that the genus Sphingorhabdus should be reclassified into two genera (Clade I and Clade II), for which the original genus name, Sphingorhabdus , is proposed to be retained only for Clade I, and a new genus named as Parasphingorhabdus gen. nov. is proposed for Clade II with four new combinations: Parasphingorhabdus marina comb. nov., Parasphingorhabdus litoris comb. nov., Parasphingorhabdus flavimaris comb. nov. and Parasphingorhabdus pacifica comb. nov. Moreover, Sphingopyxis baekryungensis should represent a novel genus in the family Sphingomonadaceae , for which the name Novosphingopyxis gen. nov. is proposed, with a combination of Novosphingopyxis baekryungensis comb. nov. The study provides a new insight into the taxonomy of closely related genera in the family Sphingomonadaceae .

Description of Novosphingopyxis iocasae sp. nov., isolated from deep sea sediment from the Mariana Trench, and emended description of the genus Novosphingopyxis

“…The description of genus Novosphingopyxis is as given previously [1], with the following emendation from the present study. Cells are aerobic or faculatively anaerobic.…”

“…At the time of writing, the genus Novosphingopyxis comprises only one species, i.e. Novosphingopyxis baekryungensis DSM 16222 T , which was originally classified as a member of the genus Sphingopyxis , and was reclassified as the type species of the genus Novosphingopyxis in 2020 [1, 2]. Members of the family Sphingomonadaceae have been isolated from diverse environments, such as river [3], cold spring [4], gasoline-contaminated soils [5], a wastewater treatment plant [6], an abandoned lead–zinc mine [7] and a hot spring [8].…”

“…The predominant respiratory quinone is ubiquinone-10 (Q-10) and the major fatty acids are C 18 : 1 ω7 c , C 16 : 0 , C 16 : 1 ω7 c , C 17 : 1 ω6 c and C 14 : 0 2-OH [1]. The major polar lipids included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and sphingoglycolipids [1]. In this study, we proposed a novel species of the genus Novosphingopyxis , strain PB63 T , isolated from a deep-sea sediment sample collected from the Mariana Trench.…”

“…The members of the genus Novosphingopyxis are Gram-stain-negative, rod-shaped and aerobic. The predominant respiratory quinone is ubiquinone-10 (Q-10) and the major fatty acids are C 18 : 1 ω7 c , C 16 : 0 , C 16 : 1 ω7 c , C 17 : 1 ω6 c and C 14 : 0 2-OH [1]. The major polar lipids included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and sphingoglycolipids [1].…”

Sphingorhabdus lacus sp. nov. and Sphingorhabdus profundilacus sp. nov., isolated from freshwater environments

“…The genus Sphingorhabdus of the family Sphingomonadaceae was first proposed by Jogler et al [9] with the description of Sphingorhabdus planktonica and the reclassification of three Sphingopyxis species. Recently, four species of the genus Sphingorhabdus have been transferred to the novel genus Parasphingorhabdus [10], and therefore the genus Sphingorhabdus currently comprises nine species with validly published names which have been isolated from diverse environments such as freshwater [11,12], seashore sediment [13], arctic soil [14], seawater [15], wetland [16] and contaminated Petri dish [17]. The genus is characterized by Gram-stain-negative and aerobic bacteria that contain ubiquinone-10 (Q-10) as the major respiratory quinone, spermidine as the major polyamine and phosphatidylethanolamine (PE), phosphatidylmethylamine (PME), phosphatidylcholine (PC), phosphatidylglycerol (PG), diphosphatidylglycerol (DPG) and SGL as the major polar lipids [9,12,14].…”