Novel surface-based methodologies for investigating GH11 xylanase-lignin derivative interactions

Area of Science:

• Biotechnology
• Biochemistry
• Materials Science

Background:

• Lignocellulose recalcitrance hinders efficient biofuel production.
• Lignin's interaction with enzymes limits biomass susceptibility to hydrolysis.
• Understanding these interactions is key to optimizing lignocellulose deconstruction.

Purpose of the Study:

• Develop surface plasmon resonance (SPR) methodologies.
• Investigate interactions between xylanase (Tx-xyn11) and phenolic compounds/lignin oligomers.
• Gain novel insights into lignocellulose bioprocessing limitations.

Main Methods:

• Developed two SPR approaches: immobilizing Tx-xyn11 or lignin oligomers (dehydrogenation polymer - DHP) on sensor surfaces.
• Utilized Langmuir-Blodgett technique on SAM-modified gold and covalent coupling to a dextran matrix for stable lignin layers.
• Studied interactions in the liquid phase using SPR.

Main Results:

• Observed weak affinity and over-stoichiometric binding between Tx-xyn11 and phenolic molecules in the first approach.
• Successfully prepared stable lignin layers on sensor surfaces using two novel methods.
• Detected weak and non-specific interactions between Tx-xyn11 and DHP.

Conclusions:

• Established robust SPR methodologies for studying enzyme-lignin interactions.
• Demonstrated weak, non-specific binding of xylanase to lignin, providing insights into biomass recalcitrance.
• Findings contribute to optimizing enzymatic hydrolysis for lignocellulosic ethanol production.