Biofilm Formation Capabilities of Lactobacillus Species Isolated from Selected Fermented Food Products Using a Statistical Approach

Background: This study investigates the biofilm formation capabilities of Lactobacillus species isolated from fermented cassava and corn products. Understanding biofilm formation is crucial for evaluating the probiotic potential of these species, as biofilm-forming ability influences their survival and functionality in host environments. Methods: Nine bacterial isolates, including Lactobacillus fermentum, L. ghanensis, L. delbrueckii, L. plantarum, Lactococcus lactis, L. reuteri, Lysinibacillus sphaericus, Bacillus cereus, and B. pacificus, were assessed for biofilm production using the microtiter plate assay. After crystal violet staining, optical density (OD) values were measured at 570 nm spectrophotometrically. Based on OD values, isolates were classified into four categories: no biofilm, weak, moderate, and strong biofilm formation. Statistical analyses, including two-stage least squares regression, were employed to evaluate biofilm formation trends and predictors. Results: The predictive regression model was highly significant (R² = 0.987, F = 122.618, p < 0.0001). Biofilm formation strength varied, with the highest mean percentage observed in the moderate group (31.29%), followed by weak (27.41%), strong (20.46%), and no biofilm (20.05%). Among the isolates, Lactobacillus fermentum exhibited the highest rate of strong biofilm formation (46.1%), while Lysinibacillus sphaericus showed none. Moreover, The highest biofilm formation was observed at 37°C (31.29%), followed by 25°C (27.41%), and 45°C (20.46%). Similarly, biofilm formation was highest at pH 6.5 (30.41%), followed by pH 7.5 (25.39%) and pH 4.5 (20.05%). Lactobacillus fermentum exhibited the highest strong biofilm formation (46.1%) at 37°C and pH 6.5. Conclusion: Biofilm formation in Lactobacillus species is species-specific and environmentally influenced by temperature and pH. Lactobacillus fermentum demonstrated strong biofilm formation, making it a promising candidate for probiotic applications.