The transition to alternative renewable resources for both fuel and platform chemicals in industrial processes is necessary for a more sustainable global economy that is less dependent on fossil fuels. Non-food plant biomass is an abundant renewable resource which is composed of sugars and phenolic compounds. Processes have been established to derive fuels from the sugar components of plant biomass but are lacking in utilizing the phenolic compounds. A large source of phenolic compounds is the alkyl-aromatic heteropolymer lignin, which can represent up of 35% of the biomass dry weight. Thus, lignin is a potential source for bio-based production of valuable chemicals. Novosphingoium aromaticivorans is known to both degrade deconstructed lignin and metabolize aromatic compounds making it a viable organism to funnel a diverse set of plant-based phenolics into chemicals of interest. Previously, our lab was able to convert biomass aromatics into 2-pyrone-4,6-dicarboxylic acid (PDC) from an engineered N. aromaticivorans strain. This presentation will discuss strategies necessary to engineer the production of cis,cis-muconic acid (ccMA), another commodity chemical, from N. aromaticivorans. ccMA can be used in the generation of adipic acid which is a platform chemical necessary for manufacturing nylon, polyurethane, insecticides and bactericides. The chemical synthesis of adipic acid requires a high input of energy and results in large emissions of the greenhouse gas nitrous oxide (N2O). Thus, recent efforts have been focused on the biosynthesis of ccMA that can easily be transformed into adipic acid via a hydrogenation reaction. This presentation discusses both the genetic engineering of N. aromaticivorans metabolic pathway for production of ccMA, as well as, the activity of specific enzymes along this metabolic pathway. In particular, this presentation will discuss the decarboxylation of protocatechuic acid (PCA) which is necessary for the generation of catechol, a key intermediate in the formation of ccMA. This decarboxylation step is a known bottleneck in biological ccMA production. Therefore, this work investigates the activity of the putative N. aromaticivorans decarboxylase enzyme with other known decarboxylase enzymes in order to engineer a more efficient ccMA production strain.

Microbial strategies for production of cis,cis-muconic acid from lignin biomass

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.