聚羟基脂肪酸酯PHA代谢工程研究30年

Thirty years of metabolic engineering for biosynthesis of polyhydroxyalkanoates

摘要:

聚羟基脂肪酸酯 (Polyhydroxyalkanoate，PHA) 是微生物合成的可降解高分子材料，种类及性能多样，应用前景广阔，然而其大规模生产受制于它较为高昂的生产成本。30年来，代谢工程的应用日益广泛，通过代谢流调控、代谢通路改造引入新通路等方法，微生物合成PHA的效率得到了很大提高，也丰富了PHA的单体种类、结构多样性和底物多样性；同时通过改变细胞形态和PHA颗粒大小等方法实现了更加高效的下游生产处理，降低了PHA生产成本。近年来，基于极端微生物，尤其是嗜盐菌的“下一代工业生物技术” (Next generation industrial biotechnology，NGIB) 发展迅速。NGIB实现了PHA生产过程的开放性和连续性，节约能源和淡水，简化了PHA的生产过程。结合代谢工程技术，盐单胞菌可以作为多种PHA的低成本生产平台，将有望提高PHA的市场竞争力和推进其商业化。

Abstract:

Polyhydroxyalkanoate (PHA) is a family of biodegradable polyesters synthesized by microorganisms. It has various monomer structures and physical properties with broad application prospects. However, its large-scale production is still hindered by the high cost. In the past 30 years, metabolic engineering approach has been used to tune the metabolic flux, engineer and introduce pathways. The efficiency of PHA synthesis by microorganisms has been significantly improved, and the diversity of PHA monomer, structure and substrate have also been enriched. Meanwhile, by changing cell morphology and PHA particle size, more efficient downstream production process has achieved and PHA production costs have been reduced. In recent years, “Next generation industrial biotechnology” (NGIB) based on extremophiles, especially halophilic Halomonas spp., has been rapidly developed. NGIB has achieved the opening and continuous production of PHA, which simplifies the production process and saves energy and fresh water. Combined with metabolic engineering, Halomonas spp. can be transformed into low-cost production platform of numerous PHA. It is expected to improve the market competitiveness and promote the commercialization of PHA.