Engineered accumulation of protocatechuate in corn biomass can enhance biomanufacturing
Background/Objective
Protocatechuate (DHBA) serves as a precursor for a wide range of valuable bioproducts. Crops can accumulate DHBA via expression of dehydroshikimate dehydratase (QsuB). This experiment sought to overproduce DHBA in plant biomass for downstream biological upgrading.
Approach
Corn was engineered to overproduce DHBA via QsuB expression. DHBA was extracted and converted into the polymer precursor 2-pyrone-4,6-dicarboxylate (PDC) using engineered Novosphingobium aromaticivorans (Figure 1).
Results
Large amounts of DHBA was recovered in alkaline hydrolysates (APL) of engineered corn stover. A 4.8-fold increase in PDC titers was achieved through biological upgrading of APL derived from QsuB corn compared to unmodified biomass.
Impact
These results demonstrate a strategy to valorize biomass-derived DHBA into other valuable bioproducts using engineered crops and microbial strains. The proposed valorization of APL streams could improve the economics of advanced biofuels and bioproducts.