Lactobacillus mudanjiangensis sp. nov., Lactobacillus songhuajiangensis sp. nov. and Lactobacillus nenjiangensis sp. nov., isolated from Chinese traditional pickle and sourdough.

Three Gram-stain-positive bacterial strains, 11050(T), 7-19(T) and 11102(T), were isolated from traditional pickle and sourdough in Heilongjiang Province, China. These bacteria were characterized by a polyphasic approach, including 16S rRNA gene sequence analysis, pheS gene sequence analysis, rpoA gene sequence analysis, dnaK gene sequence analysis, fatty acid methyl ester (FAME) analysis, determination of DNA G+C content, DNA-DNA hybridization and an analysis of phenotypic features. Strain 11050(T) belonged to the Lactobacillus plantarum species group and shared 98.0-98.4 % 16S rRNA gene sequence similarities and 84.7-88.9 % dnaK gene sequence similarities with type strains of Lactobacillus plantarum subsp. plantarum, Lactobacillus plantarum subsp. argentoratensis, Lactobacillus pentosus, Lactobacillus paraplantarum, Lactobacillus fabifermentans and Lactobacillus xiangfangensis and had 75.9-80.7 % pheS gene sequence similarities and 90.7-92.5 % rpoA gene sequence similarities with Lactobacillus plantarum subsp. plantarum LMG 6907(T), Lactobacillus plantarum subsp. argentoratensis LMG 9205, Lactobacillus pentosus LMG 10755(T), Lactobacillus paraplantarum LMG 16673(T), Lactobacillus fabifermentans LMG 24284(T) and Lactobacillus xiangfangensis 3.1.1(T), respectively. Strain 7-19(T) was phylogenetically related to Lactobacillus thailandensis, Lactobacillus pantheris and Lactobacillus sharpeae, having 94.1-96.7 % 16S rRNA gene sequence similarities, 71.5-82.3 % pheS gene sequence similarities and 71.2-83.4 % rpoA gene sequence similarities with type strains of Lactobacillus thailandensis, Lactobacillus pantheris and Lactobacillus sharpeae, respectively. Strain 11102(T) was phylogenetically related to Lactobacillus oligofermentans, Lactobacillus suebicus, Lactobacillus vaccinostercus and Lactobacillus hokkaidonensis. Strain 11102(T) had 99.2 % 16S rRNA gene sequence similarity, 81.3 % pheS gene sequence similarity and 96.1 % rpoA gene sequence similarity with Lactobacillus oligofermentans LMG 22743(T), respectively. Strain 11102(T) shared 96.0-96.8 % 16S rRNA gene sequence similarities, 73.3-81.0 % pheS gene sequence similarities and 74.6-76.9 % rpoA gene sequence similarities with type strains of Lactobacillus suebicus, Lactobacillus vaccinostercus and Lactobacillus hokkaidonensis, respectively. Based upon the data from polyphasic characterization obtained in the present study, three novel species, Lactobacillus mudanjiangensis sp. nov., Lactobacillus songhuajiangensis sp. nov. and Lactobacillus nenjiangensis sp. nov., are proposed and the type strains are 11050(T) ( = LMG 27194(T) = CCUG 62991(T)), 7-19(T) ( = LMG 27191(T) = NCIMB 14832(T) = CCUG 62990(T)) and 11102(T) ( = LMG 27192(T) = NCIMB 14833(T)), respectively.