Triacetic acid lactone (TAL) is an important building block for a diverse set of chemicals and plastic polymers. Native pathways using microbes can serve as an environmentally-friendly and renewable source of TAL production. However, microbial production of TAL is limited to a few platform microbes. Further, native pathways using platform microbes such as E. coli show toxicity to TAL, which reduces its production. Therefore, there is a need for thiolases that provide higher yield and can be used in additional microorganisms.
Researchers at the Joint BioEnergy Institute (JBEI) have discovered novel thiolases for production of Triacetic acid lactone (TAL) via platform microorganisms. The discovered thiolases achieved production of 2.77 g/L of TAL when expressed in E. coli, which is the highest titer production reported using E. coli.
The discovered thiolases were identified from homologs of Cupriavidus necator, and their TAL production was verified by in vitro and in vivo testing. Unlike the energetically expensive native TAL-producing enzyme 2-pyrone synthase, the discovered thiolases utilize acetyl-CoA instead of malonyl-CoA as an extension unit.
The Burkholderia thiolases identified by the researchers can be engineered to further boost production of TAL in existing platform microorganisms such as E. coli, as well as other microorganisms such as yeasts.
Superior titer, rate, and yield, and titer production of TAL than current thiolases and enzymes