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Item Composition analysis of canola and intermediate wheatgrass biomass and the effects of extraction(BioResources, 2023-01) Johnsrude, Lauren M.; Scheffel, Aidan J.; Allen, Brett L.; Wettstein, Stephanie G.Knowing the composition of biomass is critical for determining accurate yields of renewable chemicals and fuels; however, nonstructural components can affect the results of standard composition procedures, leading to inaccurate reactant amounts. To remove these nonstructural components, solvent extractions can be done, but the impact on composition values has not been well-reported. For this study, compositional analysis was performed on as-received canola (Brassica napus) and intermediate wheatgrass (Thinopyrum intermedium), as well as ethanol, water, and water/ethanol extracted biomasses. Water/ethanol extraction of the intermediate wheatgrass resulted in significantly lower xylose and both acid soluble and insoluble lignin amounts when compared to the as-received analysis. Since sugar was removed during the extractions, it is recommended to use the as-received composition values for glucuronoarabinoxylans; however, the extractives may interfere with the lignin analysis and therefore, the extracted lignin values are likely more reflective of the composition.Item Influence of pretreatment, lignin extraction, and chemical modification on lignin properties and the performance of lignin-formaldehyde resins and lignin-PLA composite materials(Montana State University - Bozeman, College of Engineering, 2022) Saulnier, Brian Keith; Chairperson, Graduate Committee: David Hodge; This is a manuscript style paper that includes co-authored chapters.Bio-ethanol can be produced from lignocellulosic biomass in a biorefinery as part of a three step process, a chemical or mechanical pretreatment, enzymatic hydrolysis of the cell wall, and fermentation of these sugars to ethanol. One of the byproducts of this process is lignin, a complex biopolymer composed of a heterogeneous aromatic structure. Lignin is often burned to provide energy for the biorefinery. Incorporating lignin into higher-value products is crucial to the viability of the biorefinery process and the full utilization of the renewable carbon contained in biomass. Challenges to the inclusion of lignin in value-added products include recalcitrance of the cell wall to deconstruction and lignin extraction, heterogeneity of the lignin chemical structure, polydisperse molecular weight distributions, and low reactivity. In this thesis we address these challenges by using feedstock selection, selection of pretreatment and lignin extraction process conditions, lignin fractional precipitation, and direct chemical modification of lignin. Chapter 1 provides an overall introduction and background of previous work. Chapter 2 uses a diverse panel of corn stover genotypes subjected to dilute acid pretreatment using a variety of process conditions. The response of the biomass to pretreatment was characterized with special attention given to glucose hydrolysis yields and p-coumarate (pCA) content. Chapter 3 uses a single corn stover source pretreated using a variety of dilute acid conditions followed by two different lignin extraction methods. The influence of pretreatment and lignin extraction conditions on lignin properties was characterized with focus on lignin pCA content. This study found that lignin-formaldehyde resins using lignin from optimized process conditions achieved lap shear strengths higher than conventional phenol-formaldehyde resins. Chapter 4 addresses lignin polydispersity and heterogeneity using the fractional precipitation of lignin from formic acid liquors to obtain differing molecular weight lignin fractions while allowing for successful enzymatic hydrolysis of cellulose. Chapter 5 uses fractional precipitation of corn stover alkali liquors along with modification using propylene carbonate to obtain a panel of multi-component biopolymer fractions for manufacture of biopolymer-PLA composite materials. These materials were fully characterized finding materials made with modified biopolymers exhibited better lignin dispersion, and improved thermal and mechanical properties.Item Autohydrolysis and deligninfication of wheat straw(Montana State University - Bozeman, College of Engineering, 1985) Nakaoka, Ronald KurtItem Acid and enzymatic hydrolysis of autohydrolyzed lignocellulosic substrates(Montana State University - Bozeman, College of Engineering, 1987) Lamar, David AllenItem Isolation and characterization of thermostable alkaline bacteria with ligninolytic potential(Montana State University - Bozeman, College of Engineering, 2012) Popovitch, Ari Elizabeth; Chairperson, Graduate Committee: Brent M. PeytonThermus thermophilus ST and S42 were isolated from high pH (9) and temperature (70°C) hot springs in the Alvord Desert, Oregon and the Heart Lake Geyser Basin in Yellowstone National Park, Wyoming, respectively. The two strains exhibited lignin degrading potential at pH 9 and 70°C, due to their ability to utilize the lignocellulose degradation products kraft lignin, ferulic acid, cinnamic acid, and p-coumaric acid for growth. Growth on the soluble fraction of alkaline pretreated lignocellulose sources, corn stover, corn cob and lodgepole pine was evaluated. The two isolates grew to higher cell yields due of the presence of kraft lignin, corn stover and lodge pole pine when supplemented with glucose. Dye decolorizing activity was confirmed with Remazol Brilliant Blue R (RBBR), an industrial dye and lignin analog compound. Laccase mediated 2,2' azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) activity was observed for both isolates when 0.05 mM CuSO 4 was supplemented to the growth medium. Ligninolytic bacteria capable of growth at pH 9 and 70°C are potentially useful with alkaline lignocellulose pretreatment methods to depolymerize and remove lignin prior to the production of second generation biofuel.