- Enhanced ethanol production from wheat straw by integrated storage and pre-treatment (ISP).
Enhanced ethanol production from wheat straw by integrated storage and pre-treatment (ISP).
Integrated storage and pre-treatment (ISP) combines biopreservation of moist material under airtight conditions and pre-treatment. Moist wheat straw was inoculated with the biocontrol yeast Wickerhamomyces anomalus, the xylan degrading yeast Scheffersomyces stipitis or a co-culture of both. The samples and non-inoculated controls were stored at 4 or 15 ยฐC. The non-inoculated controls were heavily contaminated with moulds, in contrast to the samples inoculated with W. anomalus or S. stipitis. These two yeasts were able to grow on wheat straw as sole source of nutrients. When ethanol was produced from moist wheat straw stored for four weeks at 4 ยฐC with S. stipitis, an up to 40% enhanced yield (final yield 0.15 g ethanol per g straw dry weight) was obtained compared to a dry sample (0.107 g/g). In all other moist samples, stored for four weeks at 4 ยฐC or 15 ยฐC, 6-35% higher yields were obtained. Thus, energy efficient bio-preservation can improve the pre-treatment efficiency for lignocellulose biomass, which is a critical bottleneck in its conversion to biofuels.