IN VITRO PROBIOTIC CHARACTERIZATION AND MOLECULAR IDENTIFICATION OF LACTIPLANTIBACILLUS PLANTARUM FROM GERMINATED WHEAT AND CAULIFLOWER SOURDOUGH

Abstract

This study aimed to develop a functional sourdough incorporating germinated wheat flour and dehydrated cauliflower flour, and to isolate, evaluate, and characterize the dominant lactic acid bacteria (LAB) obtained from the fermented product. Microbial isolation and morphological characterization revealed Lactiplantibacillus plantarum as the dominant strain. Molecular identification employing 16S rRNA gene sequencing and BLAST analysis confirmed the isolate as Lactiplantibacillus plantarum (GenBank accession: PV342492.1), showing 98–100% similarity with reference strains in the NCBI GenBank database. The isolate exhibited strong amylolytic activity with an amylolytic index of 1.9, indicating effective starch degradation during fermentation. Protease and lipase activities were also detected, suggesting the isolate’s role in protein and lipid hydrolysis, which improves the flavour and textural quality of sourdough products. In vitro probiotic assessments demonstrated that the isolate maintained high viability under acidic conditions (77.78% at pH 2.0) and in the presence of bile salts, showing a survival rate of 74.16% after 24 h at 0.3% bile concentration. Antimicrobial activity was observed against foodborne pathogens including Staphylococcus aureus, Escherichia coli, and Salmonella species. Phylogenetic analysis confirmed the close evolutionary relationship of the isolate with other L. plantarum strains, validating its dominance in the vegetable-enriched sourdough ecosystem. The incorporation of cauliflower flour appeared to support robust growth and stability of L. plantarum during fermentation without hindering microbial proliferation. These in vitro findings suggest that the formulated sourdough has potential for the development of high-fibre fermented bakery products; however, in vivo validation is required before specific gastrointestinal health claims can be substantiated.