Lysobacter stagni sp. nov. and Limnohabitans lacus sp. nov., isolated from a pond

Abstract

Two Gram-negative bacteria, designated as strains LF1T and HM2-2T, were isolated from an artificial pond in a honey farm at Hoengseong-gun, Gangwon-do, Republic of Korea. The 16S rRNA sequence analysis results revealed that strain LF1T belonged to the genus Lysobacter and had the highest sequence similarity to Lysobacter niastensis GH41-7T (99.0 %), Lysobacter panacisoli CJ29T (98.9 %), and Lysobacter prati SYSU H10001T (98.2 %). Its growth occurred at 20–37 °C, at pH 5.0–12.0, and in the presence of 0–2% NaCl. The major fatty acids were iso-C15 : 0, iso-C16 : 0, and summed feature 9 (iso-C17 : 1  ω9c and/or C16 : 0 10-methyl). The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, and diphosphatidylglycerol. The DNA G+C content was 67.5 mol%. The average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH) values between strain LF1T and species of the genus Lysobacter were 79.1–84.4% and 22.0–27.5 %, respectively. The 16S rRNA sequence analysis results revealed that strain HM2-2T belonged to the genus Limnohabitans and was most closely related to Limnohabitans planktonicus II-D5T (98.9 %), Limnohabitans radicicola JUR4T (98.4%), and Limnohabitans parvus II-B4T (98.4 %). Its growth occurred at 10–35 °C, at pH 5.0–11.0, and in the presence of 0–2% NaCl. The major fatty acids were C16 : 0 and summed feature 3 (C16 : 1  ω7c/C16 : 1  ω6c). The major polar lipid was phosphatidylethanolamine. The DNA G+C content was 59.9 mol%. The ANI and dDDH values between strain HM2-2T and its closely related strains were 75.1–83.0% and 20.4–26.4 %, respectively. Phenotypic, genomic, and phylogenetic data revealed that strains LF1T and HM2-2T represent novel species in the genera Lysobacter and Limnohabitans, for which the names Lysobacter stagni sp. nov. and Limnohabitans lacus sp. nov. are proposed, respectively. The type strain of Lys. stagni is LF1T (=KACC 23251T=TBRC 17648T), and that of Lim. lacus is HM2-2T (=KACC 23250T=TBRC 17649T).