Title Limnobacter humi sp. nov., a thiosulfate-oxidizing, heterotrophic bacterium isolated from humus soil, and emended description of the genus Limnobacter Spring et al. 2001
Author Tuan Manh Nguyen1,2 and Jaisoo Kim1*
Address 1Department of Life Science, College of Natural Sciences, Kyonggi University, Suwon 16227, Republic of Korea, 2Thai Nguyen University of Agriculture and Forestry, Quyet Thang Commune, Thai Nguyen, Vietnam
Bibliography Journal of Microbiology, 55(7),508–513, 2017,
DOI 10.1007/s12275-017-6645-7
Key Words Limnobacter humi sp. nov., taxonomy, chemolithoheterotrophic, thiosulfate oxidizing
Abstract Three Gram-negative, strictly aerobic, chemolithoheterotrophic bacterial strains, designated UCM-30, UCM-33, and UCM-39T, were isolated in South Korea. Based on their 16S rRNA gene sequences, the three isolated strains were found to be similar to Limnobacter thiooxidans CS-K2T (97.41– 97.68%), Limnobacter litoralis KP1-19T (95.55–95.76%), and various genera belonging to the class Betaproteobacteria (90.34–93.34%). DNA-DNA hybridization showed 79.3–83.9% similarity between the genomic DNA of UCM-39T, UCM-30, and UCM-33, while the sequence similarity between UCM- 39T and L. thiooxidans KACC 13837T or L. litoralis LMG 24869T was 23.7% and 18.6%, respectively. The DNA G+C content of UCM 39T was 59.7 mol%, the major ubiquinone was Q-8, and the optimal oxidation rate was observed at 10 mM thiosulfate. The major fatty acids (≥ 10%) were summed features 3 (C16:1ω7c and/or C16:1ω6c) and 8 (C18:1ω7c and/or C18:1ω6c), and C16:0. The major polar lipids (diphosphatidylglycerol, phosphatidylethanolamine, and phosphatidylglycerol) were found in all members of genus Limnobacter. Based on phenotypic, physiological, and phylogenetic analyses, the UCM-39T strain was found to be significantly distinct to represent a novel species affiliated to the genus Limnobacter. We propose to name it Limnobacter humi sp. nov. with the type strain UCM-39T (=KACC 18574T =NBRC 111650T).