Sphingobium cyanobacteriorum sp. nov., isolated from fresh water.

Abstract

A novel Gram-stain-negative, yellow-pigmented, short rod-shaped bacterial strain, HBC34T, was isolated from a freshwater sample collected from Daechung Reservoir, Republic of Korea. The results of 16S rRNA gene sequence analysis indicated that HBC34T was affiliated with the genus Sphingobium and shared the highest sequence similarity to the type strains of Sphingobium vermicomposti (98.01 %), Sphingobium psychrophilum (97.87 %) and Sphingobium rhizovicinum (97.59 %). The average nucleotide identity (ANI) and digital DNA-DNA hybridisation (dDDH) values between HBC34T and species of the genus Sphingobium with validly published names were below 84.01 and 28.1 %, respectively. These values were lower than the accepted species-delineation thresholds, supporting its recognition as representing a novel species of the genus Sphingobium. The major fatty acids (>10 % of the total fatty acids) were identified as summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c). The main polar lipids were phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, two phospholipids and two unidentified polar lipids. The respiratory quinone was Q-10. The genomic DNA G+C content of HBC34T was 64.04 %. The polyphasic evidence supports the classification of HBC34T as the type strain of a novel species of the genus Sphingobium, for which the name Sphingobium cyanobacteriorum sp. nov is proposed. The type strain is HBC34T (= KCTC 8002T= LMG 33140T).