A series of investigations was undertaken regarding the biorefining of biomass for the recovery of multiple high-value products. The overall objective was to develop a simple, selective breakdown approach for flax shive, addressing three specific research areas: material properties; extraction processing; and product purification. This thesis includes five published papers and additional research all related to the topic. Flax shive represents the woody residue left over after removing fibre from flax straw. It is composed of lignified xylem tissue. Flax shive is readily available in large quantities, at low cost, and with relatively consistent particle-size and composition characteristics. Frictional behaviour investigations of bulk flax shive showed differing effects for addition of alcohols versus water. Adding any liquid significantly increased internal friction. The wall friction effects, however, depended on the liquid. Friction was increased significantly by water, but not as much by alcohols. Absorptive behaviour of flax shive, specifically liquid-holding capacity, was assessed using five liquids and compared to three other biomass materials. Flax shive was found to be a comparatively poor absorbent, a desirable behaviour for a feedstock used in aqueous- or alcohol-based processing. The first step extraction employed sodium ethoxide catalyst in anhydrous ethanol. Yield of solvent-soluble organics varied linearly with catalyst concentration. At 1.0 M the yield was 54.5 ± 14.5 mg/g dry basis (db). Analyses using 1H NMR consistently showed extracts to be phenolic in nature, and to contain no carbohydrate constituents. The second step extraction of hemicellulose polysaccharides was done using aqueous 1.0 M sodium hydroxide. The yield of carbohydrate precipitates was consistent, 99.4 ± 5.1 mg/g (db), and was unaffected by pretreatment. Analyses of polysaccharide backbone monomers showed consistently high molar ratios of xylose-to-glucose, i.e., 25.5 ± 3.4, with no mannose present. These results suggested a high concentration of glucuronoxylan polymer, likely greater than 90% by mass, with no glucomannan present. Economic evaluation showed two-stage extraction of high-value products to be a potentially viable business. Such processing also tied directly to government polices aimed at increasing value-add from agricultural materials. Overall, flax shive was found to be a desirable feedstock for recovery of high-value bio-products.

Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (leaves 127-136).

Orientador: Jackson Antônio Marcondes de Souza / Coorientador: Daniel Guariz Pinheiro / Coorientador: Luciano Takeshi Kishi / Resumo: A torta de filtro apresenta bagaço residual oriundo do processo de extração do caldo de cana-de-açúcar e quando armazenada por longos períodos, se torna um habitat ideal para o desenvolvimento de comunidades microbianas que atuam na desconstrução da lignocelulose. Nossas análises de dados de sequenciamento de DNA metagenômico sugerem que a torta de filtro armazenada por 40 dias possui uma microbiota com características funcionais e ecológicas exclusivas em relação a outros ambientes com elevada disposição de material lignocelulósico. Assim como em ambientes de compostagem, os filos mais abundantes são Actinobacteria, Proteobacteria, Firmicutes e Bacteroidetes. Dentre os principais genes que estes micro-organismos possuem, estão Glicosiltransferases, Carboidrato Esterases e Glicosil Hidrolases, que atuando em conjunto, são passíveis de desconstruírem a lignocelulose e participarem na liberação de açúcares menores, ácidos orgânicos e outros nutrientes. Neste trabalho, identificamos novas enzimas da família AA10 que oxidam a celulose cristalina, demostrando o potencial deste ambiente em possibilitar a adaptação de micro-organismos que expressam enzimas capazes de desestruturar a celulose altamente condensada, possibilitando a liberação de moléculas de glicose. A comunidade microbiana pode acessar nutrientes como Fósforo e Nitrogênio através da despolimerização da biomassa vegetal ou decomposição da microbiota morta. No ciclo biogeoquímico do nitrogênio, a evaporação de amônia é ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The filter cake presents residual bagasse from the process of extracting the sugarcane juice and when stored for long periods, it becomes an ideal habitat for the development of microbial communities that act in the deconstruction of lignocellulose. Our analyzes of metagenomic DNA sequencing data suggest that the filter cake stored for 40 days has a microbiota with unique functional and ecological characteristics compared to other environments with high lignocellulosic material. Thus in composting environments, the most abundant phyla are Actinobacteria, Proteobacteria, Firmicutes, and Bacteroidetes. Glycosyltransferases, Carbohydrate Estersases and Glycoside Hydrolases, which act together, are capable of deconstructing lignocellulose and participate in the release of smaller sugars, organic acids and other nutrients. In this work, we identify new enzymes of the AA10 family that oxidize crystalline cellulose, demonstrating the potential of this environment to enable the adaptation of microorganisms that express enzymes capable of destabilizing highly condensed cellulose, allowing the release of glucose molecules. The microbial community can access nutrients such as Phosphorus and Nitrogen through the depolymerization of the plant biomass or decomposition of the dead microbiota. In the biogeochemical cycle of nitrogen, the evaporation of ammonia is reduced by the assimilation of this substance by the microbial community, and ammonia is produced by ammonification of nitrate and... (Complete abstract click electronic access below) / Doutor

Defatted powdered jute was delignified by chlorite treatment and the hemicellulose extracted with alkali. The precipitated material was purified by washing with alcoholic hydrochloric acid and dried by solvent exchange. The hydrolysed hemicellulose yielded neutral sugar and sugar acids separated on ion exchange resins. The neutral sugar was identified as D-xylose. The sugar acid fraction contained mainly an aldobiouronic acid proved by the reduction of the methyl ester methyl glycoside with lithium aluminum hydride followed by hydrolysis to consist of D-xylose linked to a monomethyl glucose. This was shown, via its ahilide and osazone, to be 4-0-methyl-D-glucose. Methanolysis of the aldobiouronic acid yielded the methyl glycoside of a uronic acid which on treatment with diazomethane and then with methanolic ammonia gave 4-0-methyl-α-D-glucuronoamide methyl glycoside, after fractional crystallization. Reduction of the aldobiouronic acid methyl ester methyl glycoside with lithium aluminum hydride, followed by methylation and hydrolysis, gave 2,3,4,6-tetra-0-methyl-D-glucose and 3,4-di-0-methyl-D-xylose. A search for a crystalline derivative of the purified aldobiouronic acid and of its related xylitol compound formed on reduction with potassium borohydride was unsuccessful. / Science, Faculty of / Chemistry, Department of / Graduate

Die Festigkeitseigenschaften des Papiers hängen vom Gehalt und der Verteilung der Hemicellulosen über den Querschnitt der Faserwand ab. Hemicellulosen werden durch verschiedene Bleichverfahren unterschiedlich stark angegriffen und herausgelöst. Durch Untersuchungen an einem Fichtensulfitzellstoff ist es gelungen, die Auswirkungen einzelner Bleichstufen [Peroxidverstärkte Sauerstoffstufe (EOP), Ozonstufe (Z) und Peressigsäurestufe (PAA)] und Bleichsequenzen (EOP-Z-P, EOP-PAA-P) auf Faseroberfläche, Hemicellulosenzusammensetzung und -verteilung sowie auf die optischen und mechanischen Eigenschaften des daraus gebildeten Papiers aufzuzeigen. Um die Verteilung der Hemicellulosen über den Querschnitt der Faser zu beschreiben, wird das Verfahren des chemischen Abschälens verwendet und schrittweise die Faserwand entfernt. Der gebleichte bzw. abgeschälte Zellstoff wird rasterelektronenmikroskopisch untersucht, hydrolysiert und anschließend die Hemicellulosenzusammensetzung quantitativ mittels Hochdruckflüssigkeitschromatographie (HPLC) unter Nutzung eines Flüssigkeitsmassenspektrometers (LCMS) als Detektor bestimmt. Zusätzlich erfolgt die Bestimmung der Papiereigenschaften. Diese Untersuchungen bestätigen, dass die verschiedenen Hemicellulosengehalte nach den Bleichstufen Unterschiede bei den Festigkeitseigenschaften bewirken. Die Untersuchungen zeigen den positiven Effekt der Peressigsäurestufe für die Papierherstellung im direkten Vergleich zur Ozonstufe. Zusätzlich wurde auch der Einfluss des Aufschlusses geprüft. Hierzu wurden die endgebleichten Sulfitzellstoffe mit einem endgebleichten Sulfatzellstoff verglichen. / The mechanical strength of paper pulp depends strongly on the hemicellulose content and the hemicellulose distribution across the cell wall layers. Hemicelluloses get differently attacked and dissolved by different bleaching methods. The investigations with a paper grade sulphite pulp show the influence of the separate bleaching steps [hydrogen peroxide reinforced oxygen stage (EOP), ozone (Z) und peracetic acid (PAA)] and bleaching sequences (EOP-Z-P, EOP-PAA-P) of the fibre surface, hemicellulose content and distribution as well as the optical and mechanical characteristics of paper. To describe the hemicellulose distribution across the cell wall layers a procedure of a precise chemical peeling was used in order to remove stepwise the cell wall. The bleached and peeled pulp was investigated by scanning electronic microscope (SEM) to get more information about the penetration of the bleaching chemicals into the fibre surface. The hemicelluloses were determined by high performance liquid chromatography (HPLC) using a liquid chromatography mass spectrometer (LCMS) after hydrolysing polysaccharides to monosaccharides. In addition to this paper properties were analysed. This research confirms the effect of different hemicellulose compositions of the mechanical strength. The analyses represent the positive effect for paper production of the peracetic acid step in contrast to the ozone step. Additional the influence of the pulping process was determined by a sulphate pulp comparing with the sulphite pulp.

Master of Science / Department of Grain Science and Industry / Yong Cheng Shi / Isolation of hemicellulose from distillers dry grain with solubles (DDGS) was investigated. Hemicellulose fiber gum (HFG) is a mixture of hemicelluose, protein, ash and starch. It was extracted from a commercial DDGS by heating with or without alkali. Three extraction methods (water heating, alkaline heating and alkaline hydrogen peroxide heating) were evaluated. Yield of HFG and the recovery of hemicellulose were obtained. High heating temperature (100 and 120°C), alkali or hydrogen peroxide facilitated the release of hemicellulose from the cell wall matrix. However combining alkali with 2.5% H2O2 did not extract more hemicellulose out than did alkali alone. The highest hemicellulose recovery was 32% achieved by cooking at 120°C with 2% alkaline solution. Hemicellulose can function as an emulsifier in the oil-in-water emulsions, such as beverage, and potentially replace gum arabic. HFGs obtained by a series of extracting methods were applied in both the concentrated emulsion with the gum: oil: water ratio of 0.5:1: 8.5 and the diluted emulsion with the gum: oil: water ratio of 0.005: 0.01: 1. The emulsion stability was evaluated by turbidity and creaming test. HFG extracted by 2% NaOH solution at 120°C and HFG extracted by 2% NaOH and 2.5% H2O2 solution at 100°C showed the best emulsifying ability among 15 HFG samples. DDGS was produced from corn, sorghum, wheat in the lab. HFGs extracted from sorghum and wheat DDGS were compared with that from corn DDGS. The composition of the three DDGS varied in protein, fat and non-starch carbohydrate contents. Sorghum and wheat DDGS contained higher levels of protein and lower levels of fat and non-starch carbohydrate than corn DDGS. HFG was extracted by 2% NaOH solution at 100°C for one hour and purified by 100% ethanol. The yield of HFG from corn, sorghum and wheat DDGS was 21.08, 11.07, 11.64% respectively, while the hemicellulose recovery was 30.95, 29.74, 22.71% respectively. The water extractable hemicelluloses from all three DDGS had similar ratios of arabinose to xylose.

Submitted in fulfilment for the requirement of a Degree of Doctor of Technology: Biotechnology, Durban University of Technology, 2010. / The aim of this study was to evaluate T. lanuginosus for the production of hemicellulases, its yield enhancement using mutagenesis and application of a selected xylanase on bagasse pupl to assess the improvement of pulp properties. The objectives were: To determine the localization of hemicellulases in T. lanuginosus strains, To develop high yielding strains of T. lanuginosus through mutagenensis, To investigate the synthesis of xylanase by T. lanuginosus MC134, To optimize the medium components and cultural conitions of T. lanuginosus MC134 strain, To study the influence of agitation and aeration on the production of xylanase by T. lanuginosus MC134 in a fermenter, To evaluate the bleach boosting abilities of T. lanuginosus xylanase on bagasse pulp, To evaluate simultaneous xylanase production and biobleaching potential of T. lanuginosus.

"Cellulose nanocrystals, one of the most abundant materials in nature, have attracted great attention in the biomedical community due to qualities such as supreme mechanical properties, biodegradability, biocompatibility and low density. In this research, we are interested in developing a bio-inspired material-by-design approach for cellulose-based composites with tailored interfaces and programmed microstructures that could provide an outstanding strength-to-weight ratio. After a preliminary study on some of the existing biomaterials, we have focused our research on studying the nanostructure and nanomechanics of the bamboo fiber, a cellulose-based biocomposite, designed by nature with remarkable strength-to-weight ratio (higher than steel and concrete). We have utilized atomistic simulations to investigate the mechanical properties and mechanisms of interactions between cellulose nanofibrils and the bamboo fiber matrix which is an intertwined hemicellulose and lignin called lignin-carbohydrate complex (LCC). Our results suggest that the molecular origin of the rigidity of bamboo fibers comes from the carbon-carbon or carbon-oxygen covalent bonds in the main chain of cellulose. In the matrix of bamboo fiber, hemicellulose exhibits larger elastic modulus and glass transition temperature than lignin whereas lignin shows greater tendency to adhere to cellulose nanofibrils. Consequently, the role of hemicellulose is found to enhance the thermodynamic properties and transverse rigidity of the matrix by forming dense hydrogen bond networks, and lignin is found to provide the strength of bamboo fibers by creating strong van der Waals forces between nanofibrils and the matrix. Our results show that the amorphous region of cellulose nanofibrils is the weakest interface in bamboo microfibrils. We also found out that water molecules enhance the mechanical properties of lignin (up to 10%) by filling voids in the system and creating hydrogen bond bridges between polymer chains. For hemicellulose, however, the effect is always regressive due to the destructive effect of water molecules on the hydrogen bond in hemicellulose dense structure. Therefore, the porous structure of lignin supports the matrix to have higher rigidity in the presence of water molecules. "

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