Identification, safety evaluation and probiotic potential of lactic acid bacteria isolated from wheat

Lactic acid bacteria (LAB) are vital to the food and health industries, yet their diversity and probiotic potential on wheat surfaces remain underexplored. In this study, 199 Gram-positive and Catalase-negative bacterial strains were isolated and characterized from wheat grains and spikes, of which 45 were selected using RAPD-PCR and identified by 16S ribosomal DNA sequencing. The phylogenetic analysis of the 16S ribosomal DNA sequences grouped the strains into eight species: Enterococcus faecium, Pediococcus acidilactici, Pediococcus pentosaceus, Enterococcus mundtii, Enterococcus durans, Lactiplantibacillus plantarum, Lacticaseibacillus casei, and Loigolactobacillus coryniformis. The majority of Enterococcus strains exhibited hemolytic activity and were therefore excluded from further analysis. The remaining 17 strains, most of them belonging to Lactobacillus and Pediococcus genera, were sensitive to most antibiotics commonly used in clinical practice and were not able to degrade mucin. Principal component analyses (PCA) and heat map visualization identified L. plantarum (WB1.2) and P. acidilactici (WR6) as the most promising probiotic candidates due to their strong surface hydrophobicity, auto-aggregation capacity, and tolerance to simulated gastrointestinal conditions. Although further studies are needed, the results indicate that these strains possess probiotic and safety-related characteristics, positioning it as a promising candidate for use as starter cultures in food fermentations.