Emerging Strategies for l-DOPA Production: Integrating Plant, Chemical, Enzymatic, and Microbial Strategies

l-3,4-Dihydroxyphenylalanine (l-DOPA) remains the frontline therapeutic for disease, yet its production faces challenges in yield, cost, and sustainability. Traditional plant extraction and chemical synthesis are limited by low efficiency, harsh conditions, and environmental burden, while enzymatic and whole-cell biocatalysis offer stereoselectivity but remain constrained by enzyme stability. Microbial fermentation, empowered by metabolic engineering, has emerged as a transformative platform, enabling direct l-DOPA biosynthesis from renewable carbon sources with high specificity, mild operation, and scalability. Breakthroughs in pathway design have significantly enhanced l-DOPA production titers in microorganisms. This review summarizes recent progress in l-DOPA biomanufacturing, with an emphasis on metabolic engineering strategies, including pathway reconstruction, feedback deregulation, enhancement of precursor supply, deletion of competing pathways, shikimate pathway optimization, and improved carbon flux utilization. Collectively, these advances are driving the development of industrially viable, economically efficient, and environmentally sustainable l-DOPA production processes, paving the route for next-generation therapeutics for neurodegenerative disorders.