Euromed Research Center, Euromed University of Fez, Eco-Campus, Fez, Morocco.
Laboratory of Biotechnology, Environment, Agri-Food, and Health (LBEAS), High School of Technology, Sidi Mohamed Ben Abdallah University, Atlas Fez, Morocco.
J Food Sci. 2021 Nov;86(11):4840-4850. doi: 10.1111/1750-3841.15941. Epub 2021 Oct 12.
Twenty-four strains were isolated from 50 samples of raw cow's milk originated from different regions of Morocco. After different screening methods, one strain was selected as the highest exopolysaccharide (EPS)-producing isolate and was identified by 16S rDNA sequencing as Lacticaseibacillus rhamnosus P14. Moreover, the EPS-producing ability, bacterial growth, and pH of the medium were monitored. The optimization of culture conditions indicated that the high yield of EPS was 685.14 mg/L obtained at 42°C, with lactose as a carbon source. The characterization study showed that the purified EPS consisted of one main fraction that contained 97.67% of carbohydrates. Furthermore, the EPS was identified as a homogeneous polysaccharide, mainly composed of glucose. These results demonstrated the high EPS production ability of the selected L. rhamnosus P14, representing a promising candidate to improve the textural and sensory properties of fermented food.
从摩洛哥不同地区的 50 份生牛乳样本中分离出 24 株菌株。经过不同的筛选方法，选择了一株产胞外多糖（EPS）能力最高的菌株，并通过 16S rDNA 测序鉴定为鼠李糖乳杆菌 P14。此外，监测了 EPS 的产生能力、细菌生长和培养基的 pH 值。培养条件的优化表明，在 42°C 下以乳糖作为碳源时，EPS 的高产率为 685.14mg/L。特性研究表明，纯化的 EPS 由一个主要部分组成，含有 97.67%的碳水化合物。此外，EPS 被鉴定为一种均相多糖，主要由葡萄糖组成。这些结果表明，所选的鼠李糖乳杆菌 P14 具有较高的 EPS 生产能力，是一种有前途的候选菌株，可以改善发酵食品的质地和感官特性。
