The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China; The Science Center for Future Foods, Jiangnan University, Wuxi 214122, China.
The Science Center for Future Foods, Jiangnan University, Wuxi 214122, China.
Carbohydr Polym. 2022 Nov 1;295:119829. doi: 10.1016/j.carbpol.2022.119829. Epub 2022 Jul 7.
Non-sulfated forms of glycosaminoglycans (NSGAGs) including hyaluronan, chondroitin and heparosan with high-molecular-weight (HMW) are extensively used biomaterials, while NSGAGs oligosaccharides display strong bioactivities. However, microbial production of HMW-NSGAGs and oligosaccharides with specific size are always challenging. Here, a membrane shield strategy was developed to produce HMW-NSGAGs by recruiting type II NSGAG synthases in Corynebacterium glutamicum. By enhancing precursor supplies and reinforcing cell membrane, the MWs of hyaluronan, heparosan and chondroitin reached 4100 kDa, 3000 kDa and 2400 kDa, respectively. In parallel, a synchronized depolymerization-polymerization strategy was developed by co-expressing NSGAGs synthases and lyases. With cell membrane as a filter, we achieved the direct biosynthesis of NSGAGs tetrasaccharides and disaccharides. The titers of chondroitin, hyaluronan and heparosan tetrasaccharides and disaccharides reached 10.9 g L, 12.1 g L and 5.8 g L, respectively. The strategies developed here should also be applicable to the biosynthesis of other polysaccharides.
非硫酸化糖胺聚糖（NSGAGs）包括具有高分子量（HMW）的透明质酸、软骨素和肝素聚糖，它们被广泛用作生物材料，而 NSGAGs 低聚糖则具有很强的生物活性。然而，微生物法生产具有特定大小的 HMW-NSGAGs 和低聚糖一直具有挑战性。在这里，开发了一种膜屏蔽策略，通过在谷氨酸棒杆菌中招募 II 型 NSGAG 合成酶来生产 HMW-NSGAGs。通过增强前体供应和增强细胞膜，透明质酸、肝素聚糖和软骨素的 MW 分别达到 4100 kDa、3000 kDa 和 2400 kDa。同时，通过共表达 NSGAGs 合成酶和裂解酶，开发了一种同步解聚-聚合策略。通过细胞膜作为过滤器，我们实现了 NSGAGs 四糖和二糖的直接生物合成。软骨素、透明质酸和肝素聚糖四糖和二糖的产量分别达到 10.9 g/L、12.1 g/L 和 5.8 g/L。这里开发的策略也应该适用于其他多糖的生物合成。
