Refined regulation of polysaccharide biosynthesis in edible and medicinal fungi: From pathways to production

Abstract

Polysaccharides derived from edible and medicinal fungi (EMF) exhibit various biological activities, rendering them useful in the pharmaceutical, nutraceutical, and food industries. However, their intricate biosynthetic pathways limit their potential, necessitating a deeper understanding of their structure–function relationships. Ganoderma lucidum has emerged as a key model for elucidating polysaccharide biosynthesis in EMF. In this paper, we present a comprehensive review of the current state of research on EMF polysaccharide biosynthesis from the perspective of structure and biosynthetic pathways, and concentrate on strategies for enhancing the precise regulation of polysaccharide production. The complexity of these structures, governed by a refined biosynthetic pathway, is crucial for determining their functional diversity. This review highlights three key strategies for enhancing polysaccharide production. Genome-scale metabolic remodeling is useful for the systematic design and optimization of pathways, while profiling metabolic remodeling regulates critical genes and metabolic nodes. The regulation of enzyme activity, particularly glycosyltransferases and glycoside hydrolases, can enhance biosynthetic efficiency. Furthermore, this review identifies several future challenges pertaining to polysaccharide synthesis. We establish a robust foundation for the advanced bio-manufacturing of polysaccharides, and provide theoretical guidance, along with empirical support, to precisely regulate polysaccharide synthesis in EMF, underscoring their significance as functional foods.