“绿色塑料”聚羟基脂肪酸酯生物合成研究进展

Research progress on biosynthesis of “green plastics”:polyhydroxyalkanoates

由于化石资源日益枯竭和塑料污染加剧,迫切需求环境友好可降解的"绿色塑料".由细菌合成的具有良好生物降解性和生物相容性的聚羟基脂肪酸酯(polyhydroxyalkanoates,PHAs)被认为是最有前景的"绿色塑料"之一.概述PHAs的结构、材料特性和应用、生物合成代谢路径以及发酵方式,指出高昂的生产成本是限制PHAs大规模生产和应用的关键问题;总结以降低PHAs生产成本为目标的PHAs生物合成研究进展,包括PHAs合成菌株的基因工程和代谢工程优化、在开放条件下使用富集菌群发酵以及采用极端微生物合成特定PHAs.以低品质废弃生物质为原料,在开放条件下利用富集菌群合成PHAs的研究尤其受到关注,是废弃生物质高值资源化利用的一条重要途径.未来的研究中需进一步提升PHAs生产菌株的合成能力以及生产工艺的效率;有关基于富集菌群的PHAs生产,需对菌群结构和功能调控进行深入研究,构建稳定高效的PHAs合成菌群和工艺流程,以实现PHAs的低成本合成和广泛应用.

Due to the depletion of fossil fuel resources and serious plastic pollution, there is an urgent need for environmentally friendly “green plastics”. Polyhydroxyalkanoates(PHAs) synthesized by bacteria are biodegradable, biocompatible, and are one of the most promising “green plastics”. This review summarizes the structure, material properties, and applications of PHAs, their biosynthetic metabolic pathways, and fermentation modes, and points out that high production cost is the key problem limiting large-scale PHA production and application. It summarizes the research progress of PHA biosynthesis aimed at reducing the production cost of PHAs, including genetic engineering and metabolic engineering optimization of PHAsynthesizing strains, fermentation with enriched flora under open conditions, and synthesis of specific PHAs by extreme microorganisms. In particular, the study of PHA synthesis with enriched floras under open conditions using low-quality waste biomass as a raw material has attracted more attention. PHA production is an important method for the high-value resource utilization of waste biomass. In future, to achieve low-cost synthesis and the wide application of PHAs, it is necessary to further improve the PHA synthesis ability of the production strains,as well as the efficiency of the production process. For enriched flora-based PHA production, a thorough study of the structure and function of microbial flora is crucial for constructing stable and efficient PHA-synthesizing flora and efficient processes.