Integrated production of polyhydroxyalkanoates and rhamnolipids: Insights in cultivation conditions and metabolic engineering

Abstract

Polyhydroxyalkanoates and biosurfactants have the potential to play a significant role in emerging bioeconomic chains. With growing environmental worries about the excessive consumption of fossil fuel derivatives, significant focus has been paid to a renewable-based economy known as the circular bioeconomy. Polyhydroxyalkanoates (PHAs) are a type of biodegradable, hydrophobic, non-toxic, thermoplastic polymer created by microbial processes that have good physicochemical properties. Rhamnolipids (RhL) are amphipathic, biodegradable, and biocompatible compounds with outstanding emulsification capabilities. Unfortunately, commercial manufacturing of PHA and RhL remains limited due to their high production costs as compared to standard polymers and surfactants. The combined manufacture of PHA and RhL can lower production costs and is an ideal option for creating two widely applicable commodities on the market. This work provides a general overview of PHA and RhL co-production, focusing on the use of renewable materials and important aspects that are directly related to cultivation conditions, as well as genetic and metabolic engineering strategies to optimize PHA and RhL production.