State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, China.
BMC Microbiol. 2024 Jan 5;24(1):15. doi: 10.1186/s12866-023-03156-6.
This study aimed to isolate the rumen-derived bacteria with the ability to degrade free gossypol (FG), and to evaluate the probiotic potential in vitro for ensuring safe utilization.
The strains were anaerobically isolated from fresh rumen fluid of sheep with long-term fed cottonseed meal (CSM) with the screening agar medium containing gossypol as the sole carbon source. Afterwards, the isolated strain incubated with CSM was subjected to the determination of the FG degradation and in vitro evaluation of probiotic characteristics.
The target strain labeled Lact. mucosae LLK-XR1 [Accession number: OQ652016.1] was obtained, and its growth on MRS Liquid medium exhibited degradation efficiency of FG up to 69.5% which was significantly greater than its growth on Man-Rogosa-Sharpe medium with glucose free for 24 h (p < 0.01). Meanwhile, LLK-XR1 showed 40.652% degradation rate of FG for unautoclaved, non-pulverized, and no additional nutrients supplementation CSM. Furthermore, LLK-XR1 presented good survivability at pH 3.0 (above 88.6%), and 0.3% bile (78.5%). LLK-XR1 showed sensitivity to broad-spectrum antibiotics except Sulfamethoxazole, Ciprofloxacin and Gentamycin and significantly inhibited E. coli CICC 10,899, Staph. aureus CICC 21,600, and Salmonella. Typhimurium CICC 21,483. LLK-XR1 demonstrated good cell surface hydrophobicity and auto-aggregation ability.
Taken together, this study for the first time noted that rumen-originated Lact. mucosae LLK-XR1 with probiotic properties exhibited substantial FG degradation capacity when it was applied to the solid-state fermentation of CSM.
本研究旨在分离能够降解游离棉酚（FG）的瘤胃源细菌，并评估其体外益生菌潜力，以确保安全利用。
采用含棉酚作为唯一碳源的筛选琼脂培养基，从长期饲喂棉籽粕的绵羊新鲜瘤胃液中进行厌氧菌分离。然后，将分离到的菌株与棉籽粕共培养，进行 FG 降解测定和体外益生菌特性评价。
获得一株标记为 Lact. mucosae LLK-XR1 的目标菌株[登录号：OQ652016.1]，其在 MRS 液体培养基中的生长对 FG 的降解效率达到 69.5%，明显高于在不含葡萄糖的 Man-Rogosa-Sharpe 培养基中培养 24 小时（p<0.01）。同时，LLK-XR1 对未经灭菌、未粉碎且未添加额外营养物质的棉籽粕的 FG 降解率为 40.652%。此外，LLK-XR1 在 pH 值为 3.0（存活率高于 88.6%）和 0.3%胆汁（存活率为 78.5%）条件下具有良好的生存能力。LLK-XR1 对除磺胺甲噁唑、环丙沙星和庆大霉素以外的广谱抗生素均敏感，且对 E. coli CICC 10899、Staph. aureus CICC 21600 和 Salmonella. Typhimurium CICC 21483 具有显著抑制作用。LLK-XR1 表现出良好的细胞表面疏水性和自聚集能力。
综上所述，本研究首次发现，具有益生菌特性的瘤胃源 Lact. mucosae LLK-XR1 对棉籽粕固态发酵时具有较强的 FG 降解能力。
