Two novel strains of marine lactic acid bacteria, isolated from decaying marine algae collected from a subtropical area of Japan, are described. The isolates, designated O24-2 T and O25-2,were Gram-positive, non-sporulating and non-motile. They lacked catalase and quinones. Under anaerobic cultivation conditions, lactate was produced from glucose with the production of formate, acetate and ethanol in a molar ratio of approximately 2 : 1 : 1. Under aerobic cultivation conditions, acetate and lactate were produced from carbohydrates and related compounds. The isolates were slightly halophilic, highly halotolerant and alkaliphilic. They were able to grow in 0-17.0 % (w/v) NaCl, with optimum growth of strains O24-2 T and O25-2 at 1.0-3.0 and 1.0-2.0 % (w/v) NaCl, respectively. Growth of strain O24-2 T was observed at pH 7.5-9.5, with optimum growth at pH 8.0-8.5. Comparative 16S rRNA gene sequence analysis revealed that the isolates occupied a phylogenetic position within the genus Alkalibacterium, showing highest similarity (99.6 %) to Alkalibacterium putridalgicola T129-2-1 T . Although sequence similarity was high, the DNA-DNA relatedness value between strain O24-2 T and A. putridalgicola T129-2-1 T was 27 %, indicating that they are members of distinct species. The DNA G+C contents of O24-2 T and O25-2 were 43.7 and 44.4 mol%, respectively, and DNA-DNA relatedness between the isolates was 89 %. The cell-wall peptidoglycan was type A4b, Orn-D-Asp. The major cellular fatty acid components were C 14 : 0 , C 16 : 0 and C 16 : 1 v9c. Based on phenotypic characteristics and genetic distinctiveness, the isolates were classified as representatives of a novel species within the genus Alkalibacterium, for which the name Alkalibacterium subtropicum sp. nov. is proposed; the type strain is O24-2 T (5DSM 23664 T 5NBRC 107172 T ).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.