Ligilactobacillus cholophilus sp. nov., isolated from pickled potherb mustard (Brassica juncea Coss.)

Strain BD7642^T was isolated from Chinese pickled potherb mustard (Brassica juncea Coss.) purchased from a local market in Shanghai, PR China. A polyphasic approach, including 16S rRNA gene sequence, housekeeping gene, average nucleotide identity (ANI), digital DNA-DNA hybridization (dDDH), G+C content and phenotypic analyses, was employed to characterize strain BD7642^T. Cells of the bacterium were short round rods, Gram-stain-positive, non-spore-forming and catalase-negative. The strain grew at 30-45 °C and pH 4.0-8.0. Optimum growth occurred at 35-40 °C and pH 6.0-7.0. The strain exhibited growth with salt (NaCl) concentrations of up to 5 % (w/v). The G+C content of the strain's genomic DNA was 31.37 mol%. The major fatty acids were C_16 : 0, C_18 : 1c9 and summed feature 10 (C_18 : 1c11/t9/t6). 16S rRNA gene sequencing revealed that strain BD7642^T represents a member of the genus Ligilactobacillus and it had high sequence similarity to Ligilactobacillus aviarius NBRC 102162^T (96.73 %), Ligilactobacillus araffinosus LGM 23560 (96.66 %) and Ligilactobacillus salivarius JCM 1231^T (95.82 %). The dDDH values between strain BD7642^T and its phylogenetically related species within the genus Ligilactobacillus ranged from 12.6 to 25.4 %. The ANI values between strain BD7642^T and its closely related taxa were far lower than the threshold (95 %-96 %) used for species differentiation. Results of phylogenetic, physiological and phenotypic characterization confirmed that strain BD7642^T represents a novel species within the genus Ligilactobacillus, for which the name Ligilactobacillus cholophilus sp. nov. is proposed. The type strain is BD7642^T (=CCTCC AB 2022398^T=JCM 36074^T).