Leuconostoc litchii sp. nov., a novel lactic acid bacterium isolated from lychee

A novel lactic acid bacterium, strain MB7^T, was isolated from lychee in Taiwan. MB7^T is Gram-staining-positive, catalase-negative, non-motile, non-haemolytic, facultatively anaerobic, coccoid-shaped, heterofermentative and mainly produces d-lactic acid from glucose. Comparative analysis of 16S rRNA, pheS and rpoA gene sequences has demonstrated that the novel strain represented a member of the genus Leuconostoc. 16S rRNA gene sequencing results indicated that MB7^T had the same sequence similarity of 99.25 % to four type strains of members of the genus Leuconostoc: Leuconostoc mesenteroides subsp. dextranicum DSM 20484^T, Leuconostoc mesenteroides subsp. jonggajibkimchii DRC 1506^T, Leuconostoc mesenteroides subsp. mesenteroides ATCC 8293^T and Leuconostoc suionicum DSM 20241^T. Additionally, high 16S rRNA sequence similarities were also observed with Leuconostoc mesenteroides subsp. cremoris ATCC 19254^T (99.12 %) and Leuconostoc pseudomesenteroides NRIC 1777^T (98.69 %). When comparing the genomes of these type strains, the average nucleotide identity values and digital DNA-DNA hybridization values of MB7^T with these type strains were 76.57-80.53 and 22.0-22.6 %, respectively. MB7^T also showed different phenotypic characteristics to other most closely related species of the genus Leuconostoc, such as carbohydrate metabolizing ability, halotolerance and growth at various pHs. On the basis of phenotypic and genotypic properties, strain MB7^T represents a novel species belonging to the genus Leuconostoc, for which the name Leuconostoc litchii sp. nov. is proposed. The type strain is MB7^T (=BCRC 81077^T=NBRC 113542^T).