Improved Exopolysaccharide Production from Lacticaseibacillus Paracasei SH6 Using Mutagen EMS

Objective: This study aims to enhance exopolysaccharide (EPS) production from a local isolate of Lacticaseibacillus paracasei through ethyl methanesulfonate (EMS)-induced chemical mutagenesis. Methods: Two isolates, L. paracasei SH5 and SH6, were obtained from fermented beverages (boza and cider) and initially screened for EPS production. The SH6 isolate was subjected to EMS-induced mutation. Antibiotic-resistant mutants were selected from the inhibition zones surrounding antibiotic discs. EPS production was assessed through total soluble carbohydrate content analysis, HPLC calculations, and gene expression studies. Results: Among the selected mutants, M8 exhibited the highest EPS production, with a yield of 566 mg/100 ml compared to the wild-type isolate, which produced 362 mg/100 ml. Other mutants (M1, M4, and M7) also showed increased EPS levels, reaching 411, 488, and 457 mg/100 ml, respectively. Mutant M8 demonstrated a 1.5-fold increase in EPS production compared to the wild type. Conclusion: The findings confirm that EMS-induced mutagenesis effectively enhances EPS production in L. paracasei. This improvement has significant implications for biotechnological applications, particularly in the pharmaceutical and food industries.