Airtight Storage Method of Moist Wheat Grain with Pischia Addition Improves Ethanol Yields

In temperate countries, grain is often harvested with high moisture content, and then dried to extend storage life. Drying is an intensive energy-consuming process. If the grain is to be utilized for ethanol production, the drying process would contribute significantly to the cost of production. Scientists from the Swedish University of Agricultural Sciences investigated the use of an airtight storage method of moist wheat grain with the addition of a biocontrol agent (a yeast called, Pichia anomala), and its impact on ethanol production was assessed. As a biocontrol agent, the antifungal property of P. anomala is said to effectively prevent mold infestation on the grains. The results showed that the "ethanol yield from moist wheat [obtained from the alternative storage method] was enhanced by 14% compared with the control obtained from traditionally (dry) stored grain". The researchers also found that the addition of the biocontrol agent (P. anomala) did not affect the improvement in ethanol yield. Furthermore, the pre-treated moist grain had a better saccharification (i.e. starch-to-sugar-conversion) after enzyme (amylase) addition, compared to dry grain. The findings indicate that the alternative storage method of moist wheat grain can substantially reduce energy costs attributed to drying. The scientists said that this "provides a new opportunity to increase the sustainability of bioethanol production". The full paper can be accessed in the open access journal website, Biotechnology for Biofuels (URL above).