Advances in the microbial production of erythritol: From synthetic biological foundations to circular...

Erythritol is a four‑carbon sugar alcohol that is naturally synthesized by various microorganisms as an osmotic pressure protectant. Given its health attributes, such as natural origin and zero calories, the demand for erythritol as a sweetener in the food industry has rapidly increased. Microbial fermentation is currently the primary method for producing erythritol but faces technical bottlenecks, such as high raw material costs, low fermentation efficiency, and byproduct accumulation. This paper systematically reviews the research progress and cutting-edge strategies for enhancing the efficiency of erythritol synthesis from multiple perspectives, including the selection and reconstruction of chassis cells, exploration and modification of key enzyme elements, refined design and modification of metabolic modules, system-level metabolic network analyses and intelligent breeding, and circular biomanufacturing systems. It provides an in-depth analysis of key technologies and innovative approaches at each level, offering a forward-looking perspective on future research directions. This paper aims to provide a theoretical foundation for constructing efficient microbial cell factories and promoting the green and low-carbon manufacturing of erythritol.