Lysobacter humi sp. nov., a bacterium isolated from rice field.

Abstract

A novel bacterial strain THG-PC4T was isolated from soil sample of rice field and was characterized by using a polyphasic approach. Cells were Gram-negative, bright yellow colored, nonmotile and rod shaped. The strain was aerobic and catalase positive, optimum growth temperature, and pH were 28°C and 7, respectively. On the basis of 16S rRNA gene sequence analysis, strain THG-PC4T belongs to the genus Lysobacter and is most closely related to Lysobacter fragariae KCTC 42236T, followed by Lysobacter oryzae KCTC 22249T, Lysobacter tyrosinelyticus KCTC 42235T, Lysobacter terrae KACC 17646T, Lysobacter yangpyeongensis KACC 11407T, Lysobacter rhizosphaerae KCTC 42237T and Lysobacter niabensis KACC 11587T. In DNA-DNA hybridization tests, the DNA relatedness between strain THG-PC4T and its closest phylogenetic neighbors was below 45%. The DNA G+C content was 66.6mol%, and the predominant respiratory quinone was ubiquinone-8. Flexirubin-type pigments were found to be present. The major cellular fatty acids were iso-C16:0, iso-C17:1 ω9c, iso-C17:0 and iso-C11:0 3OH. The predominant polar lipids were phosphatidylethanolamine and phosphatidylglycerol. The DNA-DNA hybridization, genotypic, chemotaxonomic and physiological data demonstrated that strain THG-PC4T represented a novel species within the genus Lysobacter, for which the name Lysobcater humi is proposed. The type strain is THG-PC4T (=KACC 18284T=CCTCC AB 2015292T).