Lactate-based Polyester (LAHB) as a multi-functional modifier of non-biodegradable polylactide

Polylactide (PLA) is a major bio-based plastic. However, it is not fully satisfied in terms of material properties and biodegradability. To address these issues, we have created an advanced version (LAHB) of PLA copolymerized with 3- hydroxybutyrate (3HB) from renewable feedstocks using LA-polymerizing enzyme [1]-installed microbial platforms, Escherichia coli [1-3] and Caprividus necator [4]. The properties of LAHB that can gain beneficial characters derived from transparent PLA and biodegradable P(3HB) [1,2].

In this conference, I will talk the research story of LAHB from the viewpoints of improvements in material properties and biodegradability of PLA. The following topics are highlighted. (1) Overproduction strategy of high-molecular- weight LAHB [4]. (2) Marine biodegradation mechanism of LAHB [5]. (3) Multiple material improvements in PLA blended by a LAHB modifier [4]. (4) Switchable function of LAHB causing a PLA biodegradation [3]. I will summarize the highly value-added PLA by blending with LAHB as a multi-functional modifier [3,4].

References:

1. S. Taguchi et al. Proc Natl Acad Sci U S A, 105, 17323-17327 (2008).
2. S. Taguchi and K. Matsumoto. Polymer J, 53, 67-79 (2021).
3. Y. Imai et al. Int. J. Biol. Macrol., 266, 130990, DOI: 10.1016/j.ijbiomac.(2024).130990
4. S. Koh et al., ACS Sustain.Chem. & Eng., 12, 6145–6156 (2024).
5. S. Ishii et al, Polym. Degrad. Stabil., 240, 111527 (2025).

Acknowledgments: This work was supported by NEDO (grant number: JPNP18016).

After getting the Ph.D. from the University of Tokyo in 1989, he joined the Tokyo University of Science as an assistant professor and initiated the molecular evolutionary engineering of the valuable enzymes capable of catalysing industrially important reactions. In 1997, he visited to join as research scientist at the Institute of Molecular and Cellular Biology of Immune System, Luis-Pasteur University in France. After spending the decade, he joined Polymer Chemistry Laboratory of RIKEN as a senior research scientist and for the first time introduced modern approaches such as enzyme evolution to the biotechnological production of natural polyesters. He was promoted to Professor at the Graduate School of Engineering, Hokkaido University in 2004 and moved to Kobe University/Shinshu University in 2022/2025. His current main research focuses on the Synthetic Biology for novel type of polymers based on the creation of novel biological catalysts, and biologically active molecules that can be adapted to the desired environment or biosystems.