Bioconversion of cheese whey into a hetero-exopolysaccharide via a one-step bioprocess and its applications

Abstract

Continuing efforts have been made to produce functional exopolysaccharides (EPSs) using cheap substrates for valuable applications. Cheese whey is a lactose-rich byproduct of cheese-producing industries. In this research, a one-step bioprocess for the bioconversion of cheese whey to a hetero-exopolysaccharide using a ropy EPS producing strain Lactobacillus plantarum JNULCC001 with high β-galactosidase activity was performed. The prepared hetero-exopolysaccharide is named EPS-001 and composed of galactose, glucose, mannose, and arabinose with several functional groups, including carboxyl, hydroxyl, and amide groups, endowing its thermo-stable and highly negatively charged properties. The rheological analysis of the fermented whey indicates its high viscous and shear thinning (pseudoplastic non-Newtonian fluid) behavior, demonstrating the potential role of EPS-001 as a thickening and gelling agent. Besides, EPS-001 shows an excellent biosorption ability toward methylene blue (MB) and can serve as a stabilizer in the biosynthesis of selenium nanoparticles (SeNPs). Our research advances an alternative method for management of cheese whey, which may reduce its impact on the environment, and develops a novel value-added EPS for thickening, bioremediation and stabilizing nanomaterials.