生物合成聚乳酸研究进展

Polylactic acid (PLA) is a non-natural biodegradable plastic polymerized from lactic acid. It demonstrates remarkable biodegradability and serves as a significant alternative to traditional petroleum-based plastics, particularly in the background of achieving carbon peak and carbon neutrality. As a typical carbon-neutral material, PLA is increasingly recognized as a crucial raw material for fostering national economic and social development. Currently, PLA is primarily produced through a combination of biological fermentation and chemical polymerization. However, this systhesis method is fraught with complexities, high costs, and potential risks of toxic residue accumulation. Consequently, the exploration of more environmentally sustainable and efficient production methods has become a central focus in the field of PLA synthesis. With the rapid advancements in synthetic biology, protein engineering and metabolic engineering, the key enzymes of PLA biosynthesis have been gradually identified and modified, the PLA biosynthesis pathways have been designed and assembled, leading to the establishment of cell factories for one-step synthesis of PLA utilizing microorganisms with industrial properties, thereby offering a new solution for the green synthesis of PLA. Nonetheless, the biosynthesis method is confronted with challenges, including low PLA yield and suboptimal product performance, which hinder its alignment with industrial standard. Therefore, enhancing the efficiency of PLA biosynthesis and improving product performance have emerged as critical objectives in the development of PLA biosynthesis technologies. In this paper, PLA and its synthesis methods were introduced briefly, and the advantages and disadvantages of chemical synthesis and biosynthesis were systematically analyzed. Subsequently, the pathways and key enzymes of PLA biosynthesis were summarized, and the regulatory strategies of PLA biosynthesis were summarized from the aspects of protein engineering and metabolic engineering. Finally, the key challenges and future research trends in the upgrading and development of PLA biosynthesis technology were systematically analyzed and prospected, aiming to provide useful reference for the design and development of more efficient and greener PLA biosynthesis system.