Levilactobacillus humaensis sp. nov. and Lapidilactobacillus luobeiensis sp. nov., isolated from traditional Chinese pickle

Abstract

Two Gram-stain-positive bacterial strains, designated 213-9(3)^T and 30-1(2)^T, were isolated from traditional Chinese pickle, and were characterized using a polyphasic taxonomic approach. Results of 16S rRNA gene sequence analysis indicated that strain 213-9(3)^T was most closely related to Levilactobacillus paucivorans TMW 1.1424^T, Levilactobacillus huananensis 151-2B^T and Levilactobacillus lindianensis 220-4^T, having 99.7-99.9 % 16S rRNA gene sequence similarities; strain 30-1(2)^T was most closely related to Lapidilactobacillus achengensis 247-4^T, with 99.4 % 16S rRNA gene sequence similarity. Strain 213-9(3)^T shared the highest pheS (93.9 %), rpoA (99.3 %) and concatenated pheS and rpoA (97.5 %) sequence similarities to L. paucivorans TMW 1.1424^T. Strain 30-1(2)^T had the highest pheS (82.4 %), rpoA (95.5 %) and concatenated pheS and rpoA (91.2 %) sequence similarities to L. achengensis 247-4^T. The phylogenetic relationships based on concatenated pheS and rpoA sequences and whole genome sequences were identical to those based on 16S rRNA gene sequences. Strain 213-9(3)^T exhibited the highest average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values (92.7 and 48.8 %, respectively) to L. paucivorans DSM 22467^T. Strain 30-1(2)^T had the highest ANI (84.4 %) and dDDH (32.8 %) values with L. achengensis 247-4^T. Acid production from d-galactose, d-glucose, d-mannose, N-acetyl-β-glucosaminidase, arbutin, salicin, cellobiose, maltose, gentiobiose, d-tagatose and gluconate, hydrolysis of aesculin, and activity of cystine arylamidase could differentiate strain 213-9(3)^T from L. paucivorans DSM 22467^T. Acid production from l-arabinose, d-ribose, d-xylose and d-galactose, and activity of alkaline phosphatase, esterase (C4), α-mannosidase and α-fucosidase could differentiate strain 30-1(2)^T from L. achengensis 247-4^T. Based upon the data obtained in the present study, two novel species, Levilactobacillus humaensis sp. nov. and Lapidilactobacillus luobeiensis sp. nov., are proposed and the type strains are 213-9(3)^T (=CCM 9241^T=CCTCC AB 2022115^T=JCM 35554^T) and 30-1(2)^T (=CCM 9240^T=CCTCC AB 2022114^T=JCM 35553^T), respectively.

Keywords: Lapidilactobacillus; Levilactobacillus; lactic acid bacteria; pickle.