Department of Food Science, Faculty of Agriculture, Zagazig University, Zagazig 44511, Egypt.
Department of Food Science, College of Agriculture and Veterinary Medicine, United Arab Emirates University (UAEU), Al Ain, P.O. Box 15551, United Arab Emirates.
Int J Biol Macromol. 2023 Jun 15;240:124425. doi: 10.1016/j.ijbiomac.2023.124425. Epub 2023 Apr 17.
Exopolysaccharides (EPS) have attracted a great interest due to their potential health-promoting properties and industrial applications. This study aimed to investigate the physicochemical, rheological, and biological properties of an EPS produced by a potential probiotic strain Enterococcus faecalis 84B. The results show that the extracted EPS, designated EPS-84B, had an average molecular weight of 604.8 kDa, particles size diameter of 322.0 nm, and mainly composed of arabinose and glucose with a molar ratio of 1:2. Furthermore, EPS-84B exhibited a shear-thinning behavior and had a high melting point. The rheological properties of EPS-84B were strongly influenced by the type of salt than by the pH value. EPS-84B displayed ideal viscoelastic properties, with both viscous and storage moduli increasing with frequency. The antioxidant activity of EPS-84B at a concentration of 5 mg/mL was 81.1 % against DPPH and 35.2 % against ABTS. At 5 mg/mL, the antitumor activity of EPS-84B against Caco-2 and MCF-7 cell lines was 74.6 and 38.6 %, respectively. In addition, the antidiabetic activity of EPS-84B towards α-amylase and α-glucosidase was 89.6 and 90.0 %, respectively at 100 μg/mL. The inhibition of foodborne pathogens by EPS-84B was up to 32.6 %. Overall, EPS-84B has promising properties that could be utilized in food and pharmaceutical industries.
胞外多糖（EPS）因其潜在的促进健康的特性和工业应用而引起了极大的兴趣。本研究旨在研究潜在益生菌菌株粪肠球菌 84B 产生的 EPS 的理化、流变和生物学特性。结果表明，提取的 EPS，命名为 EPS-84B，平均分子量为 604.8 kDa，粒径直径为 322.0nm，主要由阿拉伯糖和葡萄糖组成，摩尔比为 1:2。此外，EPS-84B 表现出剪切稀化行为，具有较高的熔点。EPS-84B 的流变性质受盐的类型影响较大，而受 pH 值影响较小。EPS-84B 表现出理想的黏弹性，随着频率的增加，黏性和储能模量均增加。在 5mg/mL 浓度下，EPS-84B 对 DPPH 的抗氧化活性为 81.1%，对 ABTS 的抗氧化活性为 35.2%。在 5mg/mL 时，EPS-84B 对 Caco-2 和 MCF-7 细胞系的抗肿瘤活性分别为 74.6%和 38.6%。此外，在 100μg/mL 时，EPS-84B 对α-淀粉酶和α-葡萄糖苷酶的抗糖尿病活性分别为 89.6%和 90.0%。EPS-84B 对食源性病原体的抑制率高达 32.6%。总体而言，EPS-84B 具有在食品和制药行业中应用的有前途的特性。
