Exploring Antimicrobial and Antioxidant Capacities of Molecularly Characterized Lactic Acid Bacteria strains from Fermented Zea mays (Ogi)

Lactic Acid Bacteria (LAB) present during ogi fermentation exhibit notable functional traits, including antimicrobial and antioxidant capabilities. This study aims to assess the antimicrobial and antioxidant potentials of LAB strains isolated from Ogi samples. The LAB was isolated from fermented Ogi sourced from local markets using deMan, Rogosa, and Sharpe (MRS) agar. The isolates underwent biochemical and molecular characterization. Antimicrobial and antioxidant potentials, including 1,1-Diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging assay, reducing power scavenging assay, and total antioxidant activity, were investigated. Eighteen LAB strains were isolated, with Lactobacillus delbrueckii (33%), Lactobacillus plantarum (39%), Lactobacillus casei (11%), Streptococcus thermophiles (11%), and Lactobacillus fermentii (6%) being the most frequent. Notably, LABOG10, LABOG7, and LABOG14 exhibited significant inhibition against Staphylococcus aureus, E. coli, and Candida sp., respectively. The culture filtrates of these strains demonstrated potent scavenging activity. Through molecular characterization, it was determined that the three distinct isolates, namely Lactiplantibacillus plantarum (LABOG7 and LABOG14) and Streptococcus sanguinis (LABOG10), were all identified as Lactiplantibacillus plantarum. Specifically, LABOG7 and LABOG14 were designated as strains ROF1 and ROF2, respectively. The accession number OM491514.1 corresponds to the 16S rRNA sequence of Lactiplantibacillus plantarum strain ROF1, while OM491515.1 corresponds to the sequence of Lactiplantibacillus plantarum strain ROF2. LABOG10 was identified as Streptococcus sanguinis, designated as strain ROF3. Streptococcus sanquinis ROF3, Lactiplantibacillus plantarum strain ROF1, and Lactiplantibacillus plantarum strain ROF2 demonstrate significant inhibitory activity against selected pathogens. Moreover, their potent antioxidant properties suggest potential in preventing diseases associated with oxidative stress. Keywords: Fermented cereals, Antioxidant, Antimicrobial, Oxidative stress, Molecular identification