Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical and Biomolecular Engineering (BK21 Plus Program), Institute for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea.
Systems Metabolic Engineering and Systems Healthcare Cross-Generation Collaborative Laboratory, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea.
Biotechnol J. 2019 Sep;14(9):e1800426. doi: 10.1002/biot.201800426. Epub 2019 Apr 12.
Plastics, used everyday, are mostly synthetic polymers derived from fossil resources, and their accumulation is becoming a serious concern worldwide. Polyhydroxyalkanoates (PHAs) are naturally produced polyesters synthesized and intracellularly accumulated by many different microorganisms. PHAs are good alternatives to petroleum-based plastics because they possess a wide range of material properties depending on monomer types and molecular weights. In addition, PHAs are biodegradable and can be produced from renewable biomass. Thus, producing PHAs through the development of high-performance engineered microorganisms and efficient bioprocesses gained much interest. In addition, non-natural polyesters comprising 2-hydroxycarboxylic acids as monomers have been produced by fermentation of metabolically engineered bacteria. For example, poly(lactic acid) and poly(lactic acid-co-glycolic acid), which have been chemically synthesized using the corresponding monomers either fermentatively or chemically produced, can be produced by metabolically engineered bacteria by one-step fermentation. Recently, PHAs containing aromatic monomers could be produced by fermentation of metabolically engineered bacteria. Here, metabolic engineering strategies applied in developing microbial strains capable of producing non-natural polyesters in a stepwise manner are reviewed. It is hoped that the detailed strategies described will be helpful for designing metabolic engineering strategies for developing diverse microbial strains capable of producing various polymers that can replace petroleum-derived polymers.
塑料是日常生活中广泛使用的材料，主要由源自化石资源的合成聚合物制成，其积累已成为全球范围内的严重问题。聚羟基脂肪酸酯（PHA）是由许多不同的微生物合成并在细胞内积累的天然聚酯。PHA 是石油基塑料的良好替代品，因为它们具有广泛的材料性能，这取决于单体类型和分子量。此外，PHA 是可生物降解的，可以从可再生生物质中生产。因此，通过开发高性能工程微生物和高效生物工艺生产 PHA 引起了广泛关注。此外，通过代谢工程细菌的发酵生产了包含 2-羟基羧酸作为单体的非天然聚酯。例如，通过化学合成使用相应的单体发酵或化学产生的聚（乳酸）和聚（乳酸-共-羟基乙酸）可以通过代谢工程细菌一步发酵生产。最近，可以通过发酵代谢工程细菌生产含有芳香族单体的 PHA。本文综述了逐步开发能够生产非天然聚酯的微生物菌株的代谢工程策略。希望描述的详细策略有助于设计代谢工程策略，以开发能够生产替代石油衍生聚合物的各种聚合物的不同微生物菌株。
