Antioxidant Activities Of Exopolysaccharides Research Articles

Characterization of structure and antioxidant activity of exopolysaccharides from endophytic Lysinibacillus sphaericus Ya6 under acid-base stress

In this study, the structure and antioxidant activity of exopolysaccharides (EPS) produced by Lysinibacillus sphaericus Ya6 under different acid-base stresses were investigated. The structure of EPS was analyzed by UV-visible and mid-IR, and the monosaccharide composition and the molecular weight were determined by High-performance liquid chromatography (HPLC) and high-performance gel permeation chromatography respectively. The findings indicated that EPS produced by Lysinibacillus sphaericus Ya6 was a homogenous polysaccharide with a molecular weight of 79.25 kDa that was composed of mannose and glucose. The molecular weight and monosaccharide composition of polysaccharides changed under acid-base stress conditions. With the addition of the acid-base stress level, the logarithmic growth period of Lysinibacillus sphaericus Ya6 was prolonged for a short while, but later growth rates and EPS production under stress conditions were all higher than under the control. In vitro determinations found that acid-base stress boosted the antioxidant activity of EPS. Particularly under conditions of alkaline stress, DPPH radical scavenging capacity and superoxide anion scavenging of EPS were higher than those of the control, and their capacities to scavenge DPPH was increased from 39.30% (the control) to 95.65% at pH 10.0, which was close to ascorbic acid's (95.77%) as a positive control.

Relationship of Gene-Structure-Antioxidant Ability of Exopolysaccharides Derived from Lactic Acid Bacteria: A Review.

Polysaccharides derived from lactic acid bacteria (LAB) have widespread industrial applications owing to their excellent safety profile and numerous biological properties. The antioxidant activity of exopolysaccharides (EPS) offers defense against disease conditions caused by oxidative stress. Several genes and gene clusters are involved in the biosynthesis of EPS and the determination of their structures, which play an important role in modulating their antioxidant ability. Under conditions of oxidative stress, EPS are involved in the activation of the nonenzyme (Keap1-Nrf2-ARE) response pathway and enzyme antioxidant system. The antioxidant activity of EPS is further enhanced by the targeted alteration of their structures, as well as by chemical methods. Enzymatic modification is the most commonly used method, though physical and biomolecular methods are also frequently used. A detailed summary of the biosynthetic processes, antioxidant mechanisms, and modifications of LAB-derived EPS is presented in this paper, and their gene-structure-function relationship has also been explored.

Effect of salinity on the biochemical characteristics and antioxidant activity of exopolysaccharide of Porphyridium purpureum FACHB 806

Porphyridium exopolysaccharide (EPS) is a kind of high-value biopolymer with various biological activities secreted by microalgae belonging to Porphyridium genus. Salinity is one of the important environmental factors affecting the growth of microalgae. In order to study the effect of salinity, the yield, biochemical characteristics and antioxidant activity of EPS in Porphyridium purpureum FACHB 806 cultured at four salinity levels (5‰, 20‰, 35‰ and 50‰) were investigated in this study. The results demonstrated that P. purpureum FACHB 806 could grow at all salinity levels. The highest cell density and EPS yield per cell were 6.6 × 107 cells·mL-1 and 29.1 pg·cell-1, which were obtained in the 20‰ and 50‰ salinity, respectively. With the increase of salinity, the percentage of xylose and galactose decreased while the percentage of glucose increased. Among all salinity levels, the 5‰ salinity group achieved the maximum contents of total carbohydrate and uronic acid of EPS, and the 50‰ salinity obtained the highest protein content of EPS. Compared to the 20‰ and 35‰ salinity groups, EPS of the 5‰ and 50‰ salinity showed stronger hydroxyl radical scavenging ability. These results indicated that salinity could influence the yield, biochemical composition and antioxidant activity of EPS, which will provide a new strategy to improve the yield and antioxidant activity of EPS.

Production, characterization and antioxidant activity of exopolysaccharide from Sporidiobolus pararoseus PFY-Z1.

At present, the study on exopolysaccharid is mainly focused on lactic acid bacteria, and the research on exopolysaccharide produced by yeast, especially Sporidiobolus pararoseus, is relatively few. Therefore, the aim of this study was to explore the characterization and antioxidant activities of a novel neutral exopolysaccharide SPZ, which was isolated and purified from S. pararoseus PFY-Z1. The results showed that SPZ was mainly composed of mannose, followed by glucose, with a molecular weight was 24.98kDa, had O-glycosidic bonds, no crystalline, and no triple helix structure. Based on fourier transform-infrared, high-performance liquid chromatography and nuclear magnetic resonance analyses, SPZ was identified to be a exopolysaccharide with some side chains, presence of α-, β-pyranose ring and nine sugar residues. Furthermore, the morphology features of SPZ have performed a relatively rough and uneven surface, covered with small pores and fissures. Moreover, SPZ had higher antioxidant activities and the maximum scavenging abilities of ⋅OH, NO2- and reducing power were 28.05 ± 0.73%, 92.76 ± 1.86% and 0.345 ± 0.024, respectively. Hence, SPZ could be used as a potential antioxidant application in the food and pharmaceutical industries.

Improved production and antioxidant activity of exopolysaccharides by submerged culture of Lentinula edodes by the addition of lignocellulose

The objective of this study was to investigate the effect of addition of four different lignocellulose (water-treated corn straw, water-treated xylosma sawdust, alkali-treated corn straw and alkali-treated xylosma sawdust) on the production and antioxidant activity of exopolysaccharides by Lentinula edodes. To evaluate the antioxidant activity of polysaccharides, the analyses of 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging activity, lipid peroxidation inhibition rate and erythrocyte hemolysis inhibition rate were carried out. The result clearly indicated that the exo-polysaccharide production and antioxidant activity by L.edodes mycelium was enhanced in varying degrees via the decomposition of lignocellulose. The yield of exo-polysaccharide in alkali-treated corn straw group was the highest (0.351g/L), which was 31.06% higher than that in control group after 5 days of submerged fermentation. High DPPH radical scavenging activity was observed in water-treated xylosma sawdust group, which decreased with the extension of fermentation time (23.15%-44.06%). Alkali-treated groups performed better than water-treated groups in terms of lipid peroxidation inhibitory activity. As for hemolysis inhibition activity toward erythrocytes, xylosma sawdust groups showed stronger oxidation resistance than corn straw groups.

Evaluation of anti-tumor effect of the exopolysaccharide from new cold-adapted yeast, Rhodotorula mucilaginosa sp. GUMS16 on chronic myeloid leukemia K562 cell line

Recently, the development and application of fungal exopolysaccharides (EPS) as natural biopolymers are on the rise. The present study is based on the investigation of possible antiproliferative and antioxidant activities of EPS from the Rhodotorula mucilaginosa sp. GUMS16 on BCR-ABL positive cells (K562). The cytotoxicity, colony formation assays lactate and dehydrogenase (LDH) activity were performed to assess the possible cancer cell death. To elucidate the underlying antiproliferative mechanism of the EPS, cell cycle analysis following real-time PCR (gene expression assessment) were evaluated. The results indicated that, the EPS with an IC50 dose of 1500 μg/ml, reduced the viability of K562 cells without having toxic effects on normal cells as well as decrease in size and number of colonies in EPS-treated group (p < 0.0001). The increase of LDH was 2.75 times more than the control (p < 0.0001). Gene expression revealed up- and down-regulation of apoptotic and anti-apoptotic genes in EPS group compared with the control. Moreover, the DPPH scavenging activity of the EPS in treated cells was significantly higher than the control group (p < 0.0001). Taken together, we concluded that the EPS from GUMS16 strain is able to inhibit the growth of K562 cells besides having antioxidant activities.

Structural Characterization and Antioxidant Activity of Exopolysaccharide from Soybean Whey Fermented by Lacticaseibacillus plantarum 70810.

Soybean whey is a high-yield but low-utilization agricultural by-product in China. In this study, soybean whey was used as a substrate of fermentation by Lacticaseibacillus plantarum 70810 strains. An exopolysaccharide (LPEPS-1) was isolated from soybean whey fermentation by L. plantarum 70810 and purified by ion-exchange chromatography. Its preliminary structural characteristics and antioxidant activity were investigated. Results show that LPEPS-1 was composed of mannose, glucose, and galactose with molar ratios of 1.49:1.67:1.00. The chemical structure of LPEPS-1 consisted of →4)-α-D-Glcp-(1→, →3)-α-D-Galp-(1→ and →2)-α-D-Manp-(1→. Scanning electron microscopy (SEM) revealed that LPEPS-1 had a relatively rough surface. In addition, LPPES-1 exhibited strong scavenging activity against DPPH and superoxide radicals and chelating ability on ferrous ion. This study demonstrated that soybean whey was a feasible fermentation substrate for the production of polysaccharide from L. plantarum 70810 and that the polysaccharide could be used as a promising ingredient for health-beneficial functional foods.

Comparison on characterization and antioxidant activity of exopolysaccharides from two Porphyridium strains

Comparison on characterization and antioxidant activity of exopolysaccharides from two Porphyridium strains

Effect of intense pulsed light on Lactobacillus bulgaricus exopolysaccharide yield, chemical structure and antioxidant activity

SummaryIn this work, IPL technology was used for improving the production of exopolysaccharide (EPS) in Lactobacillus bulgaricus. The effects of fluence per pulse, pulse number and pulse distance were investigated. Through GC–MS, Fourier transform infrared (FT‐IR), 1H nuclear magnetic resonance (1H NMR), X‐ray diffraction (XRD) and scanning electron microscopy (SEM) study the influence on EPS primary chemical structure and surface morphology. The antioxidant activity of EPS was evaluated by DPPH, Fe2+ chelating and reducing power assays. The findings demonstrate that IPL could be a novel environment protection method for improving the production of EPS. The research results provide a theoretical basis for whether IPL is a new type of environmental protection method and can be used to improve EPS production.

Influences of drying methods on the structural, physicochemical and antioxidant properties of exopolysaccharide from Lactobacillus helveticus MB2-1

In this study, in order to evaluate influences of different drying methods on the structural characteristics, physicochemical properties and antioxidant activities of exopolysaccharides (EPS) from Lactobacillus helveticus MB2-1, three drying methods, including spray-drying (SD), freeze-drying (FD) and spray freeze-drying (SFD), were applied to dry EPS. Results showed that different drying procedures had no significant influence on the primary structure and constituent monosaccharides of EPSs. However, the surface morphology of the three dried EPSs varied greatly in size and shape due to different drying processes. Among three dried EPSs, the particle size distribution of spray freeze-dried EPS (SF-EPS) was relatively narrower and uniform. Additionally, SF-EPS behaved better apparent viscosity and emulsifying property than spray-dried EPS (S-EPS) and freeze-dried EPS (F-EPS). SF-EPS exhibited stronger antioxidant activities when compared with S-EPS and F-EPS, according to the results of scavenging activities on different radicals and chelating activity on ferrous ion. Overall, SFD was the appropriate method for industrial production of EPS from Lactobacillus helveticus MB2-1 with better physicochemical properties and antioxidant activities.

Effect of tween 40 and ethanol on the secretion, structure and antioxidant activities of exopolysaccharides from Inonotus rickii.

In this study, the effects of Tween 40 and ethanol supplementation on the secretion, structure and antioxidant activities of exopolysaccharide (EPS) from Inonotus rickii were investigated. It was observed that Tween 40 and ethanol displayed a stimulatory effect on EPS secretion. The EPSs obtained by the addition of Tween 40 (EPS-T), ethanol (EPS-E) and control (EPS-C) were purified by Sepharose CL-6B gel chromatography and molecular weights of EPS-T, EPS-E and EPS-C were estimated to be 22.1, 30.0, and 40.5 kDa, respectively. Monosaccharide composition analysis indicated that EPS-T, EPS-E and EPS-C were mainly composed of mannose and glucose. Furthermore, EPS-E exhibited better OH• and DPPH scavenging activities than those of EPS-C and EPS-T, which might be associated with its molecular characterization.

Medium composition optimization, structural characterization, and antioxidant activity of exopolysaccharides from the medicinal mushroom Ganoderma lingzhi

To contribute towards effective exploitation and utilization of natural antioxidants, response surface methodology (RSM) was employed to optimize the medium composition for the production of exopolysaccharides from the medicinal mushroom Ganoderma lingzhi (GLEPS). An optimal medium for GLEPS production was gave through Plackett-Burman design, path of steepest ascent, and Box-Behnken design as follows: glucose (59.62 g/L), yeast extract (10.03 g/L), CaCO3 (0.2 g/L), thiamine (45.13 mg/L), KH2PO4 (1.0 g/L), peptone (1.5 g/L), Tween 80 (10.26 mL/L), ZnSO4 (0.3 g/L), mannitol (1.5 g/L), MgSO4 (0.5 g/L), and aspartate (8.86 g/L). The GLEPS yield obtained was 3.57 ± 0.21 g/L-3.16-fold higher than that produced in basal medium alone. The resulting GLEPS rich in uronic acid, d-mannose, l-rhamnose, and d-glucose, was a heteropolysaccharide with high-molecular weights (475,000 kDa and 21.6 kDa, 87.97%). It was demonstrated that the GLEPS with higher carbohydrate and uronic acid contents exhibited strong in vitro antioxidant activities via radical scavenging, reductive capacity, and chelation of transition metal catalysis. These findings indicated that RSM is an efficient tool to predict the composition of culture medium required for maximizing GLEPS yield, and GLEPS had potent antioxidant activities and could be explored as a novel natural antioxidant in functional food or medicine.

Fractionation, characterization and antioxidant activity of exopolysaccharide from fermentation broth of a Xylaria nigripes

In the present study, three main polysaccharide fractions, Xn-40, Xn-50, and Xn-80, were purified from fermentation broth cultures of Xylaria nigripes (Xns) by fractional precipitation with gradient concentrations of ethanol (40%, 50%, and 80%). In vitro antioxidant assay showed that Xn-40 was stronger than the others. The IC50 value of DPPH radical scavenging was 1,300 mg/L, and ABTS radical scavenging was 699.16 mg/L, respectively. Its functional group features were determined by Fourier transform-infrared spectroscopy (FT-IR). The results revealed the general characteristic absorption peaks of polysaccharides. We further investigated the antioxidant activity on human keratinocyte (HaCaT) cells. Our data demonstrated that polysaccharides of Xns had no cytotoxicity on HaCaT cells. Moreover, Xn-40 can significantly reduce AAPH-induced generates reactive oxygen species (ROS) generation in vitro. Comprehensive analysis results indicate that graded ethanol precipitation can effectively separate the polysaccharides that have antioxidant activity and Xns could be explored as a natural antioxidant.

Effect of carbon source on production, characterization and bioactivity of exopolysaccharide produced by Phellinus vaninii Ljup.

The effect on different three carbon source (i.e. glucose, fructose and sucrose) on production, chemical characterization and antioxidant activity of exopolysaccharide (EPS) produced by Phellinus vaninii Ljup was investigated in this study. Amongst carbon sources examined, glucose and sucrose were favorable for the mycelia growth, while the maximum EPS yield was achieved when sucrose was employed. The predominant carbohydrate compositions in EPSs identified were gluconic acid, glucose, mannose and galactose acid. Then, FT-IR spectral analysis revealed prominent characteristic groups in EPSs. EPSs molecule exist as nearly globular shape form in aqueous solution. The variation also affects antioxidant activities by investigated by using hydroxyl and DPPH radical scavenging assay. Sucrose was best carbon source from the viewpoint of antioxidant activity due to the relatively high contents of galactose in the EPS with moderate molecular weight and polydispersity.

Antioxidant and Antimicrobial Activities of Exopolysaccharides from Yoghurt Starter

The <i>in vitro</i> antimicrobial and antioxidant activities of the exopolysaccharide (EPS) extracted from yoghurt starter were investigated. Antimicrobial activity tests were carried out using disc diffusion methods with <i>Escherichia coli, Staphylococcus aureus</i> and <i>Streptococcus</i> D, <i>Proteus</i> spp and the yeast of <i>Candida albicans</i>. The antioxidant properties were evaluated using the test of DPPH free radical trapping. The results show that the EPS has weak antimicrobial activity against the tested strains with inhibitions zones ranging from 9 to 13 mm. EPS could reduce the free radical (DPPH) to diphenylpicrylhydrazine a yellow-colored at 24.25% showing antioxidant activity less than that of ascorbic acid which was 69.79%.

Retraction Notice: Liquid Fermentation of Ganoderma applanatum and Antioxidant Activity of Exopolysaccharides.

[This retracts the article on p. 224 in vol. 9.].

Structural Elucidation and Antioxidant Activities of Exopolysaccharide from L. helveticus SMN2-1

Koumiss is a traditional fermented dairy product and known for its unique physiological actions. An attempt was made to purify exopolysaccharide produced by LAB in Koumiss and antioxidant activity of the exopolysaccharide. In total, 55 EPS-producing strains were isolated from 12 koumiss samples and 3 strains with ability of higher EPS-producing were identified by 16S rRNA gene sequence as Lactobacillus Helveticus, Enterococcus duran and Leuconostoc lactis respectively. The structural analysis of purified EPS-I produced by Lactobacillus Helveticus SMN2-1 was performed by FTIR analysis. The EPS as important extracellularbioactive molecules had a molecular mass of 8.5×105 Da and good antioxidant activity with high hydroxyl andsuperoxide radicals scavenging abilities. The diversity of lactic acid bacteria in koumiss and structure and antioxidant activity of exopolysaccharide from L. helveticus SMN2-1 were verified that might be contributed to koumiss for its physiological actions.

Effect of Tween 80 and Acetone on the Secretion, Structure and Antioxidant Activities of Exopolysaccharides from Lentinus tigrinus.

In this study, the effects of the addition of Tween 80 and acetone on secretion, structure and antioxidant activities of Lentinus tigrinus exopolysaccharides (EPS) were investigated. It was found that Tween 80 and acetone displayed a stimulatory effect on EPS secretion. The EPS obtained by the addition of Tween 80 (EPS-T), acetone (EPS-A) and control (EPS--C) were purified by Sepharose CL-6B gel filtration chromatography and molecular mass of purified fractions was estimated to be 22.1, 137 and 12 kDa, respectively. Monosaccharide composition analysis indicated that EPS-T, EPS-A and EPS-C were mainly composed of glucose and mannose. Congo Red test indicated that EPS-T and EPS-A had a highly ordered conformation of triple helix, while EPS-C had a random coil conformation. Furthermore, EPS-A exhibited higher DPPH scavenging and antiproliferative activities than EPS--C and EPS-T, which might be attributed to the molecular mass.

Liquid Fermentation of Ganoderma applanatum and Antioxidant Activity of Exopolysaccharides

The medium composition and fermentation conditions of Ganoderma applanatum(GA) strain were optimized by the liquid shake flask fermentation, and the antioxidant activity of exopolysaccharides was investigated. The results showed that the optimal conditions of the liquid fermentation of GA strain were as follows: Carbon source was corn powder, nitrogen source was soy powder, the initial pH was 6.0, the inoculum size was 8％, the fermentation temperature was 32oC, the fermentation time was 7 d. The exopolysaccharides of GA strain could scavenge hydroxyl radicals(HR) and superoxide anion radicals(SAR), and the concentration of exopolysaccharides was positively related to the antioxidant activity.

Liquid Fermentation of Ganoderma applanatum and Antioxidant Activity of Exopolysaccharides

The medium composition and fermentation conditions of Ganoderma applanatum(GA) strain were optimized by the liquid shake flask fermentation, and the antioxidant activity of exopolysaccharides was investigated. The results showed that the optimal conditions of the liquid fermentation of GA strain were as follows: Carbon source was corn powder, nitrogen source was soy powder, the initial pH was 6.0, the inoculum size was 8％, the fermentation temperature was 32oC, the fermentation time was 7 d. The exopolysaccharides of GA strain could scavenge hydroxyl radicals(HR) and superoxide anion radicals(SAR), and the concentration of exopolysaccharides was positively related to the antioxidant activity.