Ethanol yields and cell wall properties in divergently bred switchgrass genotypes

Authors

Gautam Sarath, USDA Central-East Regional Biomass Center, Lincoln, NEFollow
Bruce S. Dien, USDA-ARS National Center for Agricultural Utilization ResearchFollow
Aaron J. Saathoff, USDA Central-East Regional Biomass Center, Lincoln, NEFollow
Kenneth P. Vogel, USDA Central-East Regional Biomass Center, Lincoln, NEFollow
Robert B. Mitchell, USDA Central-East Regional Biomass Center, Lincoln, NEFollow
Han Chen, University of Nebraska-LincolnFollow

Date of this Version

2011

Citation

Bioresource Technology 102 (2011) 9579–9585; doi:10.1016/j.biortech.2011.07.086

Comments

Published by Elsevier Ltd. This article is a U.S. government work, and is not subject to copyright in the United States.

Abstract

Genetic modification of herbaceous plant cell walls to increase biofuels yields is a primary bioenergy research goal. Using two switchgrass populations developed by divergent breeding for ruminant digestibility, the contributions of several wall-related factors to ethanol yields was evaluated. Field grown low lignin plants significantly out yielded high lignin plants for conversion to ethanol by 39.1% and extraction of xylans by 12%. However, across all plants analyzed, greater than 50% of the variation in ethanol yields was attributable to changes in tissue and cell wall architecture, and responses of stem biomass to diluteacid pretreatment. Although lignin levels were lower in the most efficiently converted genotypes, no apparent correlation were seen in the lignin monomer G/S ratios. Plants with higher ethanol yields were associated with an apparent decrease in the lignification of the cortical sclerenchyma, and a marked decrease in the granularity of the cell walls following dilute-acid pretreatment.