Comparative genomic analysis of and the characterization of novel motile species.

The genus was proposed as a novel genus in the in 2022. However, the phylogenetic relationship between and other heterofermentative lactobacilli, and the genetic and physiological properties of this genus remain unclear. This study aimed to determine the phylogenetic relationship between and the two closest genera, and , by the phylogenetic analysis and calculation of (core gene) pairwise average amino acid identity. Targeted genomic analysis showed that fructose bisphosphate aldolase was only present in the genome of . Mannitol dehydrogenase was found in genomes of , , and . Untargeted genomic analysis identified the presence of flagellar genes in but not in other closely related genera. Phenotypes related to carbohydrate fermentation and motility matched the genotypes. Motility genes were organized in a single operon and the proteins shared a high amino acid similarity in the genus . The relatively low similarity of motility operons between and other motile lactobacilli indicated the acquisition of motility by the ancestral species. Our findings facilitate the phylogenetic, genetic, and phenotypic understanding of the genus .ImportanceThe genus is a heterofermentative genus in the which includes predominantly isolates from cocoa fermentations in tropical climates. Despite the relevance of the genus in food fermentations, genetic and physiological properties of the genus are poorly characterized and genome sequences became available only after 2020. This study characterized strains of the genus by functional genomic analysis, and by determination of metabolic and physiological traits. Phylogenetic analysis revealed that is the evolutionary link between rod-shaped heterofermentative lactobacilli and the coccoid clade with the genera and as closest relatives. is the only heterofermentative genus in the which comprises predominantly motile strains. The genomic, physiological, and metabolic characterization of may facilitate the potential use of strains of the genus as starter culture in traditional or novel food fermentations.