Engineered Accumulation of Protocatechuate in Corn Biomass to Enhance Biomanufacturing

Area of Science:

• Biotechnology and Bioengineering
• Plant Molecular Biology
• Sustainable Chemistry

Background:

• Corn stover is a valuable lignocellulosic biomass resource for biofuels and bioproducts.
• In-planta accumulation of coproducts can improve biomass value and support a bioeconomy.

Purpose of the Study:

• To engineer corn for overproduction of protocatechuate (DHBA) in its biomass.
• To assess the impact of DHBA accumulation on biomass composition and downstream processing.

Main Methods:

• Transgenic corn lines were created using a bacterial dehydroshikimate dehydratase (QsuB) gene.
• DHBA accumulation, lignin composition, and extractable compounds were analyzed.
• Biological upgrading of biomass hydrolysates was performed using engineered bacteria.

Main Results:

• Engineered corn accumulated up to 2.9% DHBA (dry weight) in leaf and stem biomass as glucosides.
• DHBA accumulation altered lignin composition, increasing the syringyl/guaiacyl ratio and p-coumarate abundance.
• Biological upgrading of hydrolysates from QsuB corn yielded 375% higher 2-pyrone-4,6-dicarboxylate titers.

Conclusions:

• Genetic engineering of corn to overproduce DHBA is feasible and enhances biomass value.
• DHBA-enriched corn stover facilitates improved bioproduct manufacturing.
• This strategy offers a pathway for sustainable production of biofuels and chemicals from agricultural waste.