Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.
A & F Biotech. Ltd., Burnaby, BC V5A3P6, Canada.
Carbohydr Polym. 2024 Sep 1;339:122292. doi: 10.1016/j.carbpol.2024.122292. Epub 2024 May 17.
Through adaptive laboratory evolution (ALE) of Sphingomonas sp. ATCC 31555, fermentation for production of low-molecular-weight welan gum (LMW-WG) was performed using glycerol as sole carbon source. During ALE, GPC-MALS analysis revealed a gradual decrease in WG molecular weight with the increase of adaptation cycles, accompanied by changes in solution conformation. LMW-WG was purified and structurally analyzed using GPC-MALS, monosaccharide composition analysis, infrared spectroscopy, NMR analysis, atomic force microscopy, and scanning electron microscopy. Subsequently, LMW-WG obtains hydration, transparency, antioxidant activity, and rheological properties. Finally, an in vitro simulation colon reactor was used to evaluate potential prebiotic properties of LMW-WG as dietary fiber. Compared with WG produced using sucrose as substrate, LMW-WG exhibited a fourfold reduction in molecular weight while maintaining moderate viscosity. Structurally, L-Rha nearly completely replaced L-Man. Furthermore, LMW-WG demonstrated excellent hydration, antioxidant activity, and high transparency. It also exhibited resistance to saliva and gastrointestinal digestion, showcasing a favorable colonization effect on Bifidobacterium, making it a promising symbiotic agent.
通过对鞘氨醇单胞菌（Sphingomonas sp.）ATCC 31555 的适应性实验室进化（ALE），以甘油为唯一碳源进行了低分子量韦兰胶（LMW-WG）的发酵生产。在 ALE 过程中，GPC-MALS 分析表明，随着适应循环的增加，WG 分子量逐渐降低，同时溶液构象也发生变化。使用 GPC-MALS、单糖组成分析、红外光谱、NMR 分析、原子力显微镜和扫描电子显微镜对 LMW-WG 进行了纯化和结构分析。随后，LMW-WG 获得了水合、透明度、抗氧化活性和流变性能。最后，使用体外模拟结肠反应器评估了 LMW-WG 作为膳食纤维的潜在益生元特性。与使用蔗糖作为底物生产的 WG 相比，LMW-WG 的分子量降低了四倍，但仍保持中等粘度。结构上，L-Rha 几乎完全取代了 L-Man。此外，LMW-WG 还表现出出色的水合、抗氧化活性和高透明度。它还具有抵抗唾液和胃肠道消化的能力，对双歧杆菌表现出良好的定植效果，使其成为一种有前途的共生剂。
