Submitted to: BioEnergy Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/10/2014
Publication Date: 9/1/2015
Citation: Hu, G., Trupia, S., Ellberg, S. 2015. A promising low beta-glucan barley mutation of m351 for better bioethanol production use. BioEnergy Research. 8:1158-1164.
Interpretive Summary: Bioethanol has received worldwide attention as a renewable energy source. Corn is the major grain used for bioethanol production in the US. However, with increasing demand for bioethanol, corn may not meet future economic demand. Expanding the type of materials used for bioethanol production is necessary and barley addresses that need. Barley has lower ethanol production efficiency compared to corn, but a comprehensive evaluation of barley grain in ethanol production, particularly the high quality feed by-product used for livestock, may help justify its usefulness to bioethanol industry. We evaluated a barley line, m351, which has a mutation for low beta-glucan content and compared it to the corresponding wild-type line, ‘Harrington,’ for ethanol fermentation. The mutant line produced the same amount of ethanol as the wild-type, but the fermentation process was more cost-effective using m351 because the addition of beta-glucanase enzyme for beta-glucan degradation was unnecessary. The mutant line also had significantly more protein and less fiber, compared to the wild-type, making it a better quality feed by-product. The m351 line contains several characteristics that make it valuable to use directly in bioethanol production and in breeding efforts that expand and improve upon barley as a bioethanol resource.
Technical Abstract: Bioethanol is an important liquid fuel complement. Barley is an alternative raw material for ethanol production and its byproduct is a nutritious feed. The barley m351mutant line, which has a mutation for low beta-glucan content, was tested for its ethanol production efficiency and feed fraction quality in a pilot fermentation experiment. Grain samples of m351 and the corresponding wild type, Harrington, were treated/untreated with beta-glucanase during the ethanol production process. Compared to the corresponding wild type, m351 produced the same amount of ethanol, however it showed better fermentation efficiency as shown by greater mass loss at time points of 22, 39, 45, and 62 hours. Mass loss efficiency in m351 with no beta-glucanase was significantly different from that of the wild-type with beta-glucanase at those same time points. More importantly, the feed fraction derived from the fermentation process showed 5% more protein and 7% less beta-glucan than that from Harrington, indicating that the feed fraction from m351 was more nutritious than the wild type. The experiments provided evidence that m351 is a useful genetic resource for developing barley cultivars for use in bioethanol production while simultaneously providing a feed fraction suitable for livestock.