Gene Expression, Structural Characterization, and Functional Properties of Exopolysaccharide Produced From Potential Probiotic Enterococcus faecalis NOC219 Strain

Abstract

This study aimed to reveal the structural characterization and functional properties of microbial EPS-NOC219 material produced by the Enterococcus faecalis NOC219 strain with high EPS yield isolated from yogurt, with simultaneously, demonstrating the potential of this EPS for future industrial applications. According to the results of the analyses made for this aim, it was determined that the NOC219 strain contains the epsB, p-gtf-epsEFG, and p-gtf-P1 genes. In addition, it was also revealed that the EPS-NOC219 structure is expressed by the epsB, p-gtf-epsEFG, and p-gtf-P1 genes and has a heteropolymeric feature consisting of glucose, galactose, and fructose units. According to the results of the analyses made for this aim, it was determined that the EPS-NOC219 structure, which was produced from the NOC219 strain containing the epsB, p-gtf-epsEFG, and p-gtf-P1 genes, had a heteropolymeric structure consisting of glucose, galactose, and fructose units. On the other hand, it was shown that this structure had a thickener property, high heat stability exhibited a pseudoplastic flow behavior, and had a high melting point. This showed that the EPS-NOC219 had high heat stability and could be used as a thickener in heat treatment processes. In addition, it was revealed that it is suitable for plasticized biofilm production. On the other hand, the bioavailability of this structure was demonstrated with its high antioxidant activity (55.84%) against DPPH radicals and high antibiofilm activity against Escherichia coli (77.83%) and Listeria monocytogenes (72.14%) pathogens. These results suggest that the EPS-NOC219 structure may be an alternative natural resource for many industries as it has strong physicochemical properties and a healthy food-grade adjunct.