Date of Graduation
Master of Science in Biological Engineering (MS)
Biological and Agricultural Engineering
Danille J. Carrier
Second Committee Member
Thomas A. Costello
Biological sciences; Applied sciences; Biofuel; Enzyme; Ethanol; Inhibition; Storage; Switchgrass
To produce fermentable sugars from lignocellulosic biomass feedstock, severe pretreatment conditions are needed (either high acid concentration, temperature, or retention times). High severities can produce toxic byproducts which inhibit enzymatic hydrolysis or fermentation. In order to reduce pretreatment severities (and thus increase enzyme and fermentation efficiency), the white-rot fungus Pleurotus ostreastus was seeded into square and round bales of Kanlow switchgrass (Panicum virgastum L.) and left in the field over a period of 9 month. The laccase producing fungus is believed to selectively degrade lignin, a common plant structural polymer, which can function as an enzymatic inhibitor. Samples were taken from different elevations within the bale 3, 5, 7, and 9 months after harvesting. These samples were treated at three different severities with liquid hot water pretreatment. Compositional analysis was done on the pretreated biomass, which was then enzymatically hydrolyzed with cellulases (endoglucanase and beta-glucosidase) after being washed. The yields (total recovered sugars over total present) were calculated and compared along five different variables: fungal treatment, storage time, pretreatment severity, sampling depth, and washing volumes. The results of the study found significant effects for sampling time (p=.0024) and pretreatment severity (p<.0001), but found no such significance in the effects of washing (p=.6624) and sampling depth (p=.0693). Results regarding the fungal inoculation were inconclusive, but provided the basis for the creation of experiments to be carried out in future work.
Frederick, Noaa, "Storage of Round and Square Switchgrass Bales: Effect of Storage Time and Fungal Inoculation on Saccharification Efficiency" (2015). Theses and Dissertations. 1420.