Isolation and Characterization of β-glucans with probiotic properties

Abstract

The present study attempted to characterize β-glucans produced extracellularly by microorganisms. Two bacterial isolates were screened for high β-glucan producers from curd and faeces of newborn using rapid aniline blue and congo red dye binding assays. The β-glucans produced extracellularly from both these isolates at mid to late log phases of growth had yields of 31.1mg/g and 26.1mg/g dry weight respectively and optimal pH of 7.2 at a temperature of 37°C. The purified β-glucans were determined for their physicochemical attributes using HPLC, FTIR, DLS and SEM respectively. Favourable size-structure and confirmatory signatures for β- glucans could be established from these results. The isolated β-glucans demonstrated antimicrobial activities against fungal and bacterial pathogens albeit with different potencies and significant cholesterol removal in vitro. None of the β-glucans were affected functionally upon exposure to simulated gastric trials indicating their suitability for application through foods or bioactive. The producer strains were ascertained to possess beneficial properties allowing them to be classified as GRAS. Results of this study indicate an interesting possibility of further technological applications of the microbially produced β-glucans.