Orange Peel Fiber and Tremella flava Fermented Powder Effectively Induce Exopolysaccharide Production by Lactobacillus plantarum SLC

Abstract

The aim of this study was to evaluate the effect of orange peel fiber powder (OPFP) in comparison to that of Tremella flava Chen fermented powder (TFP) on Lactobacillus plantarum SLC 13 exopolysaccharide (EPS) production. Growth of and EPS production by SLC 13 in MRS medium supplemented with different concentrations of glucose, OPFP, and TFP were investigated. The antioxidant activity of EPS and antibacterial property of the culture medium were investigated by adding 6% glucose, 2% OPFP, and 2% TFP to the SLC 13 culture medium. Supplementation with 6% glucose, 2% OPFP, and 2% TFP significantly promoted EPS production and bacterial viability. Maximum EPS production (2.6647 0.0380 g/L) of SLC 13 was observed when 2% OPFP pretreated with 3 N HCl was added to the culture medium. Supplementation of 2% OPFP treated with 20 U xylanase, 20 U cellulase, and 10 U cellulase/10 U xylanase increased the EPS production by strain SLC 13. The highest reducing power and DPPH and ABTS radical scavenging activities of EPS were observed when the culture medium was supplemented with 6% glucose. Supplementation with 6% glucose and 2% OPFP enhanced the antibacterial property of the SLC 13 medium against Staphylococcus aureus and Salmonella typhimurium, respectively. Our findings that OPFP promotes growth, EPS production and antibacterial property of SLC 13 suggest that it has potential for industrial application as an economic prebiotic.