Optimization of Exopolysaccharide Produced by Lactobacillus plantarum R301 and Its Antioxidant and Anti-Inflammatory Activities

Abstract

In this study, the yield of exopolysaccharide (EPS) from Lactobacillus plantarum R301 was optimized using a single-factor experiment and response surface methodology (RSM). After optimization, the EPS yield was increased with a fold-change of 0.85. The significant factors affecting EPS production, as determined through a Plackett–Burman design and Central Composite Design (CCD), were MgSO4 concentration, initial pH, and inoculation size. The maximum yield was 97.85 mg/mL under the condition of 0.01% MgSO4, an initial pH 7.4, and 6.4% of the inoculation size. In addition, the EPS exhibited strong antioxidant activity, as demonstrated by its ability to scavenge DPPH, ABTS, and hydroxyl radicals. The scavenging rate was up to 100% at concentrations of 4 mg/mL, 1 mg/mL, and 2 mg/mL, respectively. Moreover, the EPS also exhibited reducing power, which was about 30% that of ascorbic acid when both tended to be stable with the increased concentration. These results suggest that L. plantarum R301 EPS possesses different antioxidant mechanisms and warrants further investigation. In addition to its antioxidant activity, the EPS also demonstrated good anti-inflammatory activity by inhibiting the inflammation induced by lipopolysaccharide (LPS) in RAW 264.7 cells, which could decrease nitric oxide (NO) production and expression of the proinflammatory cytokine Il-6. These findings suggest that L. plantarum R301 EPS could be used as a potential multifunctional food additive in the food industry.

Lactic Acid Bacteria-Derived Exopolysaccharides Mitigate the Oxidative Response via the NRF2-KEAP1 Pathway in PC12 Cells

“…Based on our findings, there is a regulatory effect of L-EPSs on TOS and TAS levels in PC-12 cells induced by OS with H 2 O 2 . It has been stated in the literature that L-EPS provides balance between TOS and TAS levels, thanks to mechanisms of action such as free radical scavenging [55], metal chelation [56], lipid peroxidation [57], electron or hydrogen donation (to ROS) [58], antioxidant stimulant, and enzyme detoxification activities [59]. This view was supported by our findings in a previous study, which implied that our L-EPSs exhibited antioxidant activities (hydroxyl and superoxide anion scavenging activity, metal ion chelating activity, and lipid peroxidation activity) [35].…”

Development of Biological Coating from Novel Halophilic Exopolysaccharide Exerting Shelf-Life-Prolonging and Biocontrol Actions for Post-Harvest Applications

“…An optimal level of K + promotes osmoregulation the and maintenance of the electric potential of bacterial cell membranes, but a high K content slows down cell multiplication [34]. Along with N, P, K, and carbon source, Mg was also optimized due to its inevitable importance in cell metabolism [35]. The range of MgSO 4 content chosen was 0.25-10 g/L.…”

Drug delivery applications and future prospects of microbial exopolysaccharides

“…The RSM statistically analyzes several independent variables to predict their relationship with each other and their effects on production yield 45 ; it is being extensively employed by researchers to optimize the production of EPSs in microbes using experimental designs including Plackett-Burman Design (PBD), Box-Behnken Design (BBD) and Central Composite Design (CCD). 46,47 Table 1 summarizes some findings of recent research works on the optimization of production factors to improve EPS production from microbial sources. [44][45][46][48][49][50][51]…”

“…46,47 Table 1 summarizes some findings of recent research works on the optimization of production factors to improve EPS production from microbial sources. [44][45][46][48][49][50][51]…”

“…Isolated EPSs are mostly extracted from isolated mixtures by solvent precipitation via the addition of a polar organic (such as ethanol) that reduces the solubility of EPSs in water. 45,46 Desalting and deproteination treatments may be further carried out to purify precipitated polysaccharides. The resultant precipitate is collected by centrifugation, filtration or sedimentation and dried under pressure.…”