School of Life Science and Food Engineering, Huaiyin Institute of Technology, Huaian, China.
State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
Crit Rev Food Sci Nutr. 2021;61(4):535-552. doi: 10.1080/10408398.2020.1739000. Epub 2020 Mar 17.
Functional sugars have unique structural and physiological characteristics with applied perspectives for modern biomedical and biotechnological sectors, such as biomedicine, pharmaceutical, cosmeceuticals, green chemistry, and agro-food. They can also be used as starting matrices to produce biologically active metabolites of interests. Though numerous chemical synthesis routes have been proposed and deployed for the synthesis of rare sugars, however, many of them are limited and economically incompetent because of expensive raw starting feedstocks. Whereas, the biosynthesis by enzymatic means are often associated with high catalyst costs and low space-time yields. Microbial production of rare sugars via green routes using bio-renewable resources offers noteworthy solutions to overcome the aforementioned limitations of synthetic and enzymatic synthesis routes. From the microbial-based synthesis perspective, the lipogenic yeast is rapidly evolving as the most prevalent and unique "non-model organism" in the bio-production arena. Due to high flux tendency through the tri-carboxylic acid cycle intermediates and precursors such as acetyl-CoA and malonyl-CoA, this yeast has been widely investigated to meet the increasing demand of industrially relevant fine chemicals, including functional sugars. Incredible interest in originates from its robust tolerance to unstable pH, salt levels, and organic compounds, which subsequently enable easy bioprocess optimization. Meaningfully, GRAS (generally recognized as safe) status creates as an attractive and environmentally friendly microbial host for the manufacturing of nutraceuticals, fermented food, and dietary supplements. In this review, we highlight the recent and state-of-the-art research progress on as a host to synthesize bio-based compounds of interest beyond the realm of well-known fatty acid production. The unique physicochemical properties, biotechnological applications, and biosynthesis of an array of value-added functional sugars including erythritol, threitol, fructooligosaccharides, galactooligosaccharides, isomalto-oligosaccharides, isomaltulose, trehalose, erythrulose, xylitol, and mannitol using sustainable carbon sources are thoroughly vetted. Finally, we conclude with perspectives that would be helpful to engineer in greening the twenty-first century biomedical and biotechnological sectors of the modern world.
功能性糖具有独特的结构和生理特性，在现代生物医学和生物技术领域具有应用前景，如生物医药、制药、化妆品、绿色化学和农业食品。它们也可以用作起始基质来生产具有生物活性的目标代谢物。虽然已经提出并部署了许多化学合成路线来合成稀有糖，但是由于昂贵的原料起始原料，其中许多路线受到限制且在经济上不可行。然而，通过酶法合成往往与高催化剂成本和低时空产率相关。利用生物可再生资源通过绿色途径在微生物中生产稀有糖为克服化学和酶法合成途径的上述限制提供了值得注意的解决方案。从微生物合成的角度来看，产脂酵母正在迅速发展成为生物生产领域中最普遍和独特的“非模式生物”。由于通过三羧酸循环中间体和乙酰辅酶 A 和丙二酰辅酶 A 等前体的高通量趋势，该酵母已被广泛研究以满足包括功能性糖在内的工业相关精细化学品的不断增长的需求。对酵母的巨大兴趣源于其对不稳定 pH 值、盐度和有机化合物的强大耐受性，这使得生物过程的优化变得容易。值得注意的是，GRAS（通常被认为是安全的）地位使酵母成为制造营养保健品、发酵食品和膳食补充剂的有吸引力和环保的微生物宿主。在这篇综述中，我们强调了最近的研究进展，即酵母作为一种宿主，除了众所周知的脂肪酸生产之外，还可以合成有价值的生物基化合物。我们彻底审查了赤藓糖醇、苏糖醇、低聚果糖、半乳糖低聚糖、异麦芽低聚糖、异麦芽酮糖、海藻糖、赤藓酮糖、木糖醇和甘露醇等一系列增值功能性糖的独特物理化学性质、生物技术应用和生物合成，这些糖都是利用可持续碳源合成的。最后，我们总结了有助于在二十一世纪的现代世界中使生物医学和生物技术领域绿色化的观点。
