Delignification for Xylan for Enzymatic Hydrolysis

UMaine Alert

Posted: April 19, 2024 - 1:32 PM

At approximately 9:24 a.m. on Friday, April 19, a University of Maine graduate student was struck by a university vehicle on Long Road at the University of Maine campus in Orono. The student reports that they are at a local hospital with minor injuries.

Emergency services, including the Orono Fire Department, University Volunteer Ambulance Corps, University of Maine Police Department, Orono Police Department and Penobscot County Sheriff’s Office responded to the scene.

The university vehicle involved in the incident was a Chevrolet Express van. It was being operated by a university employee.

Counseling services and support are available for students, faculty or staff who may have been affected. The Counseling Center can be reached at 207-581-1392 and the Dean of Students Office can be reached at 207-581-1406.

The scene has been cleared and Long Road is now accessible. An investigation is being conducted by the University of Maine Police Department with assistance from the Penobscot County Sheriff’s Office Crash Reconstruction Unit. Any witnesses to the incident are encouraged to contact Lt. Noel Santiago at noel.santiago@maine.edu.

Who’s Involved?

Enzymatic Hydrolysis Research Introduction

In order to use the sugar content of hemicellulose, a major wood constituent, for generation of new products, such as ethanol or plastics, interference from lignin, another major wood component, must be eliminated. Conversely, to make use of the lignin, the sugars must be removed. We are examining methods for accomplishing both of these tasks selectively.

Research Details

We now have shown that aryl glycosides modeling the presumed connection between lignin and hemicellulose can be cleaved selectively by superoxide ion, generated at pH 12 by photolysis of hydrogen peroxide. The aromatic lignin component is oxidized all the way to carbon dioxide, which has been identified by head space gas chromatography coupled with mass spectrometry. Very little oxidation of the sugars occurs. We also find that p-methoxyphenyl ?-D-glucoside is oxidized by the laccase from T. versicolor to give cleanly ?-D-glucose and p-methoxyphenol. The phenol is then further oxidized to dimers, which are being characterized. Both of these results demonstrate the feasibility of selective delignification of hemicelluloses.

Other Research Partners

In addition to support from the FBRI, this project is also funded by the USDA through the WUR grant. Mai Nguyen (PhD candidate), Raju Kovur (MS candidate), and Venkata Makkena (MS candidate) are working on the problem in addition to Dylan Montgomery (MS candidate), who was supported by the FBRI last summer as an undergraduate.

What’s New on this Project?

Work with model compounds indicates successful delignification both enzymatically and using superoxide at pH 12. Some success has been achieved also with the xylan, although the products of delignification have not yet been characterized.