Carbohydrates serve as essential energy sources, structural components, and bioactive substances in living organisms, making the study of their synthesis methods a significant focus in chemistry and biology. The biosynthesis of glycans primarily involves two strategies: microbial biosynthesis and enzymatic synthesis. Whole-cell synthesis is advantageous due to its low cost associated with feedstocks and catalyst regeneration, high efficiency, and suitability for large-scale production. Enzymatic catalysis stands out for its efficiency, high specificity, mild reaction conditions, environmental friendliness, and precise product structure. The two strategies are widely used in the fine chemical, pharmaceutical, and food industries. However, both of them face challenges, including difficulties in product purification, poor stability and high cost arising mainly from expensive downstream separation in whole-cell synthesis and from costly enzyme preparations and activated sugar donors in enzymatic synthesis. Microfluidic technologies for glycan synthesis offer unique advantages in terms of precise regulation, reduced consumption, and a high degree of automation, effectively overcoming the limitations of both whole-cell and enzymatic synthesis of glycans. This review aims to outline the basic concepts of carbohydrates, current methods of carbohydrate synthesis, their respective advantages and disadvantages, and to discuss the benefits of droplet microfluidic synthesis. Additionally, it proposes future solutions to address the shortcomings of microfluidic technology, providing new insights and methods for glycan synthesis research. In this review, achievements in whole-cell and enzymatic synthesis of carbohydrates are summarized, and the unique advantages of droplet microfluidics in overcoming current limitations are highlighted.
Tong et al. (Sun,) studied this question.