Hassiba Benbouali University, Chlef, Algeria.
Laboratory of Microbial Biotechnology and Engineering Enzymes (LMBEE), Center of Biotechnology of Sfax (CBS), University of Sfax, Road of Sidi Mansour Km 6, P.O. Box 1177, 3018, Tunisia.
Microb Pathog. 2019 Jul;132:10-19. doi: 10.1016/j.micpath.2019.04.018. Epub 2019 Apr 17.
A new exopolysaccharide (EPS) was produced by the Lactococcus lactis F-mou strain (LT898177.1) isolated from the Sahrawi camel milk in the Bir-Naam region, Algeria. The most influential production parameters were screened by the Plackett-Burman design for enhancing EPS yield utilizing the Mech-Degla juice as a low-cost raw material. An optimum condition of a 0.49 of inoculum size, a 100 rpm of agitation rate, and a 12 h of incubation period resulted in a 301 g/L. This yield was 47 times higher than the one attained before the application of the Box-Behnken Design. Additionally, the FTIR analysis of the EPS confirmed the presence of hydroxyl, carboxyl, amide and sulphate groups. Furthermore, the SEM image showed a porous structure characterized by a flake-like basic configuration with an extremely dense assembly. The NMR studies indicated that EPS contained a backbone of→4-α-D-galactopyranose-(1→, →4, 6-α-D-glucopyranose-(1→, →6- α -D- galactopyranose -(1→ linkages plus a levan part. The EPS exhibited good water and oil holding capacities, a high antioxidant efficiency, and an excellent anti-clotting activity. EPS also showed a strong inhibitory activity against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Listeria monocytogenes, Bacillus cereus, Proteus mirabilis, Acinetobacter baumannii, Enterobacter cloacae, and Candida albicans. Overall, the mentioned findings indicated that EPS could be utilized as a natural additive in pharmaceutical, food, and cosmetic industries.
一种新的胞外多糖（EPS）由从阿尔及利亚比尔奈姆地区的撒哈拉骆驼乳中分离出的乳球菌 F-mou 菌株（LT898177.1）产生。利用 Mech-Degla 汁作为低成本原料，通过 Plackett-Burman 设计筛选出最具影响力的生产参数，以提高 EPS 产量。在最佳条件下（接种量为 0.49、搅拌速度为 100rpm、培养时间为 12h），EPS 的产量达到 301g/L，比 Box-Behnken 设计之前的产量高 47 倍。此外，EPS 的 FTIR 分析证实了存在羟基、羧基、酰胺和硫酸盐基团。此外，SEM 图像显示 EPS 具有多孔结构，其特征在于具有薄片状基本结构的极密组装。NMR 研究表明，EPS 含有→4-α-D-半乳糖吡喃糖基-(1→、→4、6-α-D-葡萄糖吡喃糖基-(1→、→6-α-D-半乳糖吡喃糖基-(1→键的骨架，以及一个低聚糖部分。EPS 具有良好的持水和持油能力、高抗氧化效率和优异的抗凝血活性。EPS 还对金黄色葡萄球菌、铜绿假单胞菌、大肠杆菌、李斯特菌、蜡状芽孢杆菌、奇异变形杆菌、鲍曼不动杆菌、阴沟肠杆菌和白色念珠菌表现出强烈的抑制活性。总的来说，这些发现表明 EPS 可以用作制药、食品和化妆品工业中的天然添加剂。
