Production of exopolysaccharide by strains of Lactobacillus plantarum YO175 and OF101 isolated from traditional fermented cereal beverage

Lactobacillus plantarum YO175 and OF101 isolates from Nigerian traditional fermented cereal gruel ‘ ogi’ , were investigated on the basis of their capability to produce exopolysaccharide (EPS) on sucrose modified deMan Rogosa Sharpe medium (mMRS). Functional groups analysis of the EPSs produced (EPS-YO175 and EPS-OF101) by Fourier-transform infrared (FT-IR) spectroscopy revealed the presence of –OH, C=O and C–H groups. The chemical composition of EPS-YO175 and EPS-OF101 showed the presence of 87.1% and 80.62% carbohydrates and 1.21% and 1.47% protein. For maximum EPS yield, three significant factors were optimized using central composite design and response surface methodology, the predicted maximum EPS produced was 1.38 g/L and 2.19 g/L, while the experimental values were 1.36 g/L and 2.18 g/L for EPS-YO175 and EPS-OF101. The EPS samples showed strong antioxidant activities in-vitro. The scale-up of the production process of the EPS will find its potential application in food industries.