Lysinibacillus chungkukjangi sp. nov., isolated from Chungkukjang, Korean fermented soybean food.

One bacterial strain 2RL3-2(T) was isolated from Chungkukjang, a traditional Korean fermented food made from soybeans, and determined to be a Gram-positive, aerobic, spore-forming rod. Growth of the novel strain was optimal at 30°C and pH 7.0. The 16S rRNA gene of strain 2RL3-2(T) showed the highest level of sequence similarity to Lysinibacillus sinduriensis BLB-1(T) (99.0%), Lysinibacillus massiliensis 4400831(T) (97.1%), Lysinibacillus xylanilyticus XDB9(T) (97.0%), and Lysinibacillus odysseyi 34hs-1(T) (96.8%). Phylogenetic analysis showed that strain 2RL3-2(T) formed a robust cluster with L. sinduriensis BLB-1(T), L. massiliensis 4400831(T), and L. odyssey 34hs-1(T). The major fatty acids were anteiso-C15:0 (47.3%), iso-C16:0 (16.3%), and anteiso-C17:0 (11.3%), and the only menaquinone was MK-7. Diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine were the major polar lipids, along with an unknown phospholipid and two unknown lipids. The peptidoglycan type was A4α, with an interpeptide bridge of l-Lys-d-Asp. DNA-DNA hybridization values between strain 2RL3-2(T) and closely related Lysinibacillus species were below 43±4%. Therefore, based on phenotypic, chemotaxonomic, and phylogenetic characteristics, it was determined that strain 2RL3-2(T) represents a novel species of the genus Lysinibacillus, for which the name Lysinibacillus chungkukjangi sp. nov. is proposed. The type strain is 2RL3-2(T) (=KACC 16626(T) =NBRC 108948(T)).