Enhanced Ethanol Production from Corn Fiber Using Thermophilic Coculture

Date:22 April 2020

Country: United States

Application

• The applications of this project include improving ethanol production from corn fiber, which is currently underutilized in biofuel production. It offers the potential for enhancing ethanol yields at existing corn ethanol facilities, contributing to increased biofuel production and more sustainable agricultural waste management.

Description

The researchers aimed to enhance ethanol production from corn fiber, an underutilized byproduct of the corn-to-ethanol process. Clostridium thermocellum was found to efficiently solubilize over 90% of the carbohydrates in autoclaved corn fiber, including its hemicellulose component glucuronoarabinoxylan (GAX). However, Thermoanaerobacterium thermosaccharolyticum and other hemicellulose-fermenting bacteria could only partially utilize GAX. The team isolated a novel thermophilic bacterium, Herbinix spp. strain LL1355, capable of consuming 85% of the recalcitrant GAX. Through genome sequencing, they identified six enzymes that hydrolyze GAX linkages, and expressed these enzymes in T. thermosaccharolyticum. The enzyme supplementation enabled T. thermosaccharolyticum to consume 78% of the GAX, compared to 53% in the parent strain, increasing ethanol yield from corn fiber by 24%.

Pathway Description:

The process involves using a thermophilic coculture of Clostridium thermocellum and Thermoanaerobacterium thermosaccharolyticum to efficiently break down corn fiber, including its recalcitrant hemicellulose component glucuronoarabinoxylan (GAX), into fermentable sugars for ethanol production.