Biosynthesis of isoprene glycol from glucose by metabolically engineered Escherichia coli

Isoprene glycol (ISPG) is a valuable humectant used in the cosmetic industry. However, its current commercial production relies on conventional petrochemical processes, which are energy-consuming and non-sustainable. To establish a green alternative, we engineered Escherichia coli to produce ISPG de novo from glucose. This engineered E. coli converts central metabolite acetyl-CoA to a non-natural metabolite 3-hydroxy-3-methylbutyryl-CoA (HMB-CoA). Subsequently, two different reduction strategies were used to reduce HMB-CoA to ISPG. Carboxylic acid reductase (CAR)-mediated reduction route resulted in higher levels of ISPG produced. Through subsequent enzyme bio-prospecting and increasing intracellular CoA availability, the resulting strain produced an ISPG titer of 2.2 g/L with a yield of 0.11 g ISPG/g glucose. This work establishes an environmentally benign process, offering an attractive and renewable alternative to petrochemical ISPG production.