LACTIC ACID BACTERIA: FROM PHYLOGENETIC RECLASSIFICATION TO FUNCTIONAL APPLICATIONS IN FOOD SYSTEMS
Lactic acid bacteria (LAB) represent major significance in microbiology and food science due to their crucial roles in food fermentation, extensive metabolic diversity, and their close association to human health. Detailed phylogenetic categorization and strain characterisation of LAB are essential for optimizing conventional and industrial fermentations, as well as for future functional food and biotechnological applications. This paper thoroughly examines the historical evolution, phylogenetic categorization, morphological, physiological, and functional attributes of the major genera of LAB. The transition from the first phenotypic-based categorization of LAB to current phylogenetic classifications utilizing 16S rRNA gene sequences and sophisticated genomic methodologies is elucidated comprehensively. The division of the genus Lactobacillus into 23 new genera and the union of the Lactobacillaceae and Leuconostocaceae families, based on whole genome sequencing and polyphasic approaches, are regarded as a significant milestone in LAB taxonomy. The links between this reclassification and metabolic profiles, ecological adaptations, and evolutionary relationships are discussed. This review compares the fermentative metabolic pathways, growth requirements, stress tolerance, and technological functions in food systems of the genera Lactobacillus, Lactococcus, Leuconostoc, Streptococcus, Pediococcus, Oenococcus, Enterococcus, Weissella, Vagococcus, and Tetragenococcus.