CHAPTER 7: White Biotechnology for Polymer Building Blocks: Strategies for Enhanced Production of Bio-based 1,3-Propanediol and Its Applications

Considering the importance of 1,3-propanediol (1,3-PDO, propane-1,3-diol, trimethylene glycol, 1,3-dihydroxypropane) as a platform molecule, as well as the exhaustion of fossil derivatives required for its chemical synthesis, glycerol, as a versatile and renewable feedstock, becomes a key enabler towards 1,3-PDO production. It has been a decade since major efforts were carried out in genetic engineering and bioprocessing aspects to improve the production titers and yield of 1,3-PDO. Subsequently, polytrimethylene terephthalate (PTT) was synthesized using 1,3-PDO, which has numerous polymer applications and became a competitor for commercialized polyethylene terephthalate (PET) and polybutylene terephthalate (PBT) polyesters. This chapter envisages a panorama of investigations on genetic aspects for improving the production of 1,3-PDO. Strategies to improve the synthesis of polyurethane and polyester from 1,3-PDO are also discussed. A detailed description of the genetics of dha regulan consisting of genes for 1,3-PDO production, along with the recent developments in genetic engineering strategies to improve the tolerance and production titers of 1,3-propanediol in individual genera, is explained. In focus with the applications of 1,3-PDO, the synthesis of various polyesters and polyurethane materials using polycondensation reactions is also described. Thus, the synthesis and properties of polyesters explained within offer valuable insights into future biomedical, pharmaceutical, and organ transplant applications.