Xylitol Biomanufacturing: Production Technologies, Industrial Applications and Future Opportunities
Xylitol is a five-carbon sugar alcohol widely used in the food, pharmaceutical, oral healthcare, and personal care industries because of its low caloric value, low glycaemic index, and non-cariogenic properties. Industrial production is mainly based on catalytic hydrogenation of xylose, which provides high conversion efficiency but requires intensive energy input, costly catalysts, and complex purification processes. Microbial fermentation has emerged as a sustainable alternative for producing xylitol from renewable lignocellulosic biomass. This review summarizes recent advances in xylitol production, with a particular focus on microbial biomanufacturing. Key developments in lignocellulosic biomass utilization, metabolic engineering, cofactor balancing, oxygen regulation, and fermentation optimization are discussed. Chemical and biological production routes are critically compared in terms of efficiency, sustainability, and industrial applicability. Recent progress in downstream purification and biorefinery integration is also highlighted. Despite substantial advances, challenges including inhibitor toxicity, limited microbial robustness, low fermentation productivity, and high purification costs continue to hinder large-scale commercialization. Future research should focus on feedstock valorization, systems metabolic engineering, process intensification, and sustainable separation technologies to improve the economic and environmental sustainability of bio-based xylitol production.