Abstract: A process for the enzymatic hydrolysis of cellulose to produce a hydrolysis product from a pre-treated cellulosic feedstock is provided. The process comprises introducing an aqueous slurry of the pre-treated cellulosic feedstock at the bottom of a hydrolysis reactor. Axial dispersion in the reactor is limited by avoiding mixing and maintaining an average slurry flow velocity of about 0.1 to about 20 feet per hour, such that the undissolved solids flow upward at a rate slower than that of the liquid. Cellulase enzymes are added to the aqueous slurry before or during the step of introducing. An aqueous stream comprising hydrolysis product and unhydrolyzed solids is removed from the hydrolysis reactor. Also provided are enzyme compositions which comprise cellulase enzymes and flocculents for use in the process. In addition, a kit comprising cellulase enzymes and flocculent is provided.

Abstract: Provided are modified cellulase enzymes exhibiting increase cellulose-hydrolyzing activity in the presence of lignin and/or reduced binding to lignin comprising modified linker peptides comprising one or more amino acid substitutions, insertions, or deletions that result in (a) a decrease in the calculated isoelectric point of the linker peptide and/or (b) an increase in the ratio of threonine:serine in the linker peptide relative to a parental linker peptide from which said modified linker peptide is derived. Also provided are genetic constructs comprising nucleic acidsequences encoding for modified cellulase enzymes, methods for the production of the modified cellulase enzymes from host strains and a process for hydrolysing cellulose with the modified cellulases in the presence of lignin.

Abstract: A modified Family 6 cellulase enzyme comprising a proline residue at position 413 is provided. Genetic constructs and genetically modified microbes comprising DNA sequences encoding the modified Family 6 cellulase are also provided. Family 6 cellulases of the invention display improved thermostability, thermophilicity, alkalophilicity, or a combination thereof, relative to the parent Family 6 cellulases. Such cellulases find use in a variety of applications in industry that require cellulase stability and activities at temperatures, pH values, or both, above that of the native enzyme.

Abstract: A process for producing ethanol from a pretreated feedstock is provided. The feedstock is selected from grasses, cereal straws, stover, and combinations thereof, and least about 80% of the feedstock has a particle length of between about 2 cm and about 40 cm. This process comprises wetting the feedstock in liquid, pressing the wet feedstock through one roll press or a series of roll presses to remove at least a portion of water and soluble substances from the wetted feedstock and to shear the feedstock to produce feedstock particles of a size suitable for pumping at a solids concentration of about 8% to about 20% when slurried. At least one roll press, or at least one roll press in the series of roll presses comprises rolls with circumferential v-shaped grooves. The pressed feedstock particles are slurried to produce a slurried feedstock having a consistency of between about 8% and about 20%, and the slurried feedstock pumped into a pretreatment reactor.

Abstract: A method for producing glucose from a lignocellulosic feedstock is provided. The method comprises pretreating the lignocellulosic feedstock with acid to produce a pretreated feedstock composition. A calcium-containing stream is provided that comprises calcium that is obtained from the lignocellulosic feedstock and a calcium carbonate-containing stream is obtained by precipitation of the calcium from the calcium-containing stream. The pH of the pretreated feedstock is adjusted with (a) the calcium carbonate-containing stream; (b) a calcium hydroxide-containing stream that is derived from said calcium carbonate-containing stream by subjecting said calcium carbonate-containing stream to calcination; or (c) a combination of the calcium carbonate-containing stream and the calcium hydroxide-containing stream.

Abstract: A continuous process for treating a lignocellulosic feedstock is provided. This method comprises pretreating the lignocellulosic feedstock under pressure in a pretreatment reactor at a pH between about 0.4 and about 2.0. One or more than one soluble base is added to this pressurized, pretreated feedstock after it exits the pretreatment reactor to adjust the pretreated lignocellulosic feedstock to an intermediate pH of between about pH 2.5 to about pH 3.5. This pressurized, partially-neutralized feedstock is then further processed at the intermediate pH. This may include flashing one or more than one time at the intermediate pH. The pH of the pressurized, partially-neutralized feedstock may then be adjusted with one or more than one base to produce a neutralized feedstock having a pH between about 4 and about 6. Prior to adjusting the pH to between about 2.5 and about 3.5, the pressurized, pretreated feedstock truly be partially depressurized.

Abstract: A process for the enzymatic hydrolysis of cellulose to produce a hydrolysis product from a pre-treated cellulosic feedstock is provided. The process comprises introducing an aqueous slurry of the pre-treated cellulosic feedstock at the bottom of a hydrolysis reactor. Axial dispersion in the reactor is limited by avoiding mixing and maintaining an average slurry flow velocity of about 0.1 to about 20 feet per hour, such that the undissolved solids flow upward at a rate slower than that of the liquid. Cellulase enzymes are added to the aqueous slurry before or during the step of introducing. An aqueous stream comprising hydrolysis product and unhydrolyzed solids is removed from the hydrolysis reactor. Also provided are enzyme compositions which comprise cellulase enzymes and flocculents for use in the process. In addition, a kit comprising cellulase enzymes and flocculent is provided.

Abstract: A fermentation process for the production of cellulase mixtures is provided. The process comprises providing a genetically modified host filamentous fungus that overexpresses a Xyr1 transcription factor and/or that is partially or completely deficient in expressing one or more hemicellulase enzyme. The host filamentous fungus is cultured in a medium comprising a carbon source. The carbon source contains from about 60 wt % to about 100 wt % hemicellulose-derived carbohydrate and less than 5% of a cellulase-inducing carbohydrate or contains from about 25 wt % to about 100% wt % hemicellulose-derived sugar alcohol in combination with from about 0 wt % to about 75 wt % glucose, glycerol or a combination thereof.

Abstract: A process for obtaining one or more than one salt of an organic acid(s), or organic acid(s), from an aqueous sugar stream comprising one or more than one mineral acid and the organic acid(s) is provided. The process comprises introducing the aqueous sugar stream to a separation system comprising one or more beds of anion exchange resin and obtaining a stream therefrom comprising the sugar. The one or more beds of anion exchange resin are then regenerated in one or more stages to produce at least one product stream comprising the organic acid, a salt of the organic acid, or a combination thereof, and a separate outlet stream comprising the mineral acid, a salt of the mineral acid, or a combination thereof. The product stream is then recovered. The separation may be conducted with two separation units, or using a single anion exchange unit.

Abstract: A process for producing a pretreated feedstock is provided. The feedstock is selected from grasses, cereal straws, stover, and combinations thereof, and least about 80% of the feedstock has a particle length of between about 2 cm and about 40 cm. This process comprises wetting the feedstock in liquid, pressing the wet feedstock through one roll press or a series of roll presses to remove at least a portion of water and soluble substances from the wetted feedstock and to shear the feedstock to produce feedstock particles of a size suitable for pumping at a solids concentration of about 8% to about 20% when slurried. At least one roll press, or at least one roll press in the series of roll presses comprises rolls with circumferential v-shaped grooves. The pressed feedstock particles are slurried to produce a slurried feedstock having a consistency of between about 8% and about 20%, and the slurried feedstock pumped into a pretreatment reactor.

Abstract: Provided are modified beta-glucosidase enzymes, derived from the Trichoderma reesei Cel3A beta-glucosidase, that exhibit improved stability at low pH, low pH and high aeration, low pH and high agitation, or low pH and elevated temperature. Also provided are genetic constructs comprising nucleotide sequences encoding for modified beta-glucosidase enzymes, methods for the production of modified beta-glucosidase enzymes from host strains and the use of the modified beta-glucosidase enzymes in the hydrolysis of cellulose.

Abstract: A process for the enzymatic hydrolysis of cellulose to produce a hydrolysis product comprising glucose from a pretreated lignocellulosic feedstock and enzymes for use in the process are provided. The process comprises partially hydrolyzing an aqueous slurry of a pretreated lignocellulosic feedstock with cellulase enzymes, one or more than one ?-glucosidase enzyme and a binding agent for binding the ?-glucosidase enzyme to fiber solids present in the aqueous slurry. The unhydrolyzed fiber solids are then separated from the hydrolyzed slurry. The separated fiber solids thus obtained are then re-suspended in an aqueous solution to produce a re-suspended slurry. The hydrolysis is then continued to produce the hydrolysis product comprising glucose.

Abstract: A method for obtaining a concentrated alcohol solution from a lignocellulosic feedstock. The lignocellulosic feedstock is hydrolyzed to prepare a sugar solution. The sugar solution is fermented to produce a fermentation broth comprising alcohol and at least about 1 g ammonium ions/kg fermentation broth. The alcohol in the fermentation broth is then concentrated by distillation to produce an alcohol-enriched vapour. Either before distillation, during distillation or during the azeotrope breaking process, the concentration of ammonia in the alcohol-enriched vapour can be reduced by acid addition to at most about 300 ppm. The alcohol in the alcohol-rich vapour is then further concentrated by an azeotrope breaking process to provide the concentrated alcohol solution.

Abstract: A method is provided for hydrolyzing polysaccharides in a lignocellulosic feedstock to produce monosaccharides or pretreating a lignocellulosic feedstock, in which an aqueous slurry of the lignocellulosic feedstock is fed into a pressurized dewatering zone wherein the feedstock is partially dewatered and then is compressed into a plug. The plug is introduced into a reaction zone that operates at a pressure (Pr) equal to greater than about 90 psia and under suitable temperature and pH conditions to hydrolyze the polysaccharides or pretreat the feedstock. The plug provides a pressure seal between the outlet of the dewatering zone and the reaction zone. The pressure (Pdwi) of the aqueous slurry of the lignocellulosic feedstock at the inlet of the dewatering device is related to Pr as follows: 0??P<the lesser of [(Pr?20 psia) and 220 psia], and where ?P is the absolute difference in pressure between Pr and Pdwi in psia.

Abstract: A method for recovering inorganic salt during processing of a lignocellulosic feedstock is provided. The method comprises pretreating the lignocellulosic feedstock by adding an acid or a base to the feedstock to produce a pretreated lignocellulosic feedstock. A soluble base or acid is then added to the pretreated lignocellulosic feedstock to adjust the pH and produce a neutralized feedstock. The neutralized feedstock is then hydrolyzed to produce an hydrolyzed feedstock and a sugar stream. Inorganic salt is recovered from a wash stream obtained from the pretreated lignocellulosic feedstock, a stream obtained from the neutralized feedstock, a stream obtained from the sugar stream, or a combination of these streams. The inorganic salt may be concentrated, clarified, recovered and purified by crystallization, electrodialysis, drying, or agglomeration and granulation, and then used as desired, for example, as a fertilizer.

Abstract: A modified Trichoderma reesei Family 6 (TrCel6A) cellulase enzyme comprising amino acid substitutions at one or more positions selected from the group consisting of 129, 322, 363 and 410 of SEQ ID NO: 1 is provided. Genetic constructs and genetically modified microbes comprising nucleic sequences encoding the modified TrCel6a cellulase are also provided. The modified TrCel6A cellulase of the invention display at least a 15% decrease in inactivation by lignin relative to a parental TrCel6A cellulase from which the modified TrCel6A is derived. Such cellulases find use in a variety of applications in industry requiring enzymatic hydrolysis of cellulose in the presence of lignin, e.g., the hydrolysis of pretreated lignocellulosic feedstocks for the production of fermentable sugars, sugar alcohols and fuel alcohols.

Abstract: A modified Family 6 glycosidase enzyme comprising amino acid substitutions at one or more positions selected from the group 182, 367, 399, 400 and 427 is provided (the position determined form alignment of a parental Family 6 glycosidase with SEQ ID NO: 1). Genetic constructs and genetically modified microbes comprising nucleic sequences encoding the modified Family 6 glycosidase are also provided. Family 6 glycosidase of the invention display decreased hydrolysis activity of beta 1-4 linked polysaccharides and increased hydrolysis activity of beta 1-3, 1-4 linked polysaccharides compared with a parental Family 6 glycosidase. Such glycosidases find use in a variety of applications in industry, e.g., in hydrolysis of beta 1-3, 1-4 linked polysaccharides during the processing of cereal grains or the production of alcohol, animal feed or food products.

Abstract: A method for recovering inorganic salt during processing of a lignocellulosic feedstock is provided. The method comprises pretreating the lignocellulosic feedstock by adding an acid to the feedstock to produce a pretreated lignocellulosic feedstock. A soluble base is then added to the pretreated lignocellulosic feedstock to adjust the pH and produce a neutralized feedstock. The neutralized feedstock is then enzymatically hydrolyzed to produce an enzyme hydrolyzed feedstock and a sugar stream. Inorganic salt is recovered from either a stream obtained from the lignocellulosic feedstock prior to the step of pretreating, a stream obtained from the pretreated lignocellulosic feedstock, a stream obtained from the neutralized feedstock, a stream obtained from the sugar stream, or a combination of these streams. The inorganic salt may be concentrated, clarified, recovered and purified by crystallization, electrodialysis drying, or agglomeration and granulation, and then used as desired, for example as a fertilizer.

Abstract: A process for producing ammonia and sulfuric acid from a stream comprising ammonium sulfate is provided. The process comprises the steps of heating the stream to produce ammonia and a decomposition product comprising one or more than one of a bisulfate salt, a pyrosulfate salt, or a combination thereof. The ammonia produced is recovered, and water is added to the decomposition product to produce a stream comprising the decomposition product. The stream comprising the decomposition product is processed by acid retardation to obtain a sulfuric acid stream and a stream comprising one or more than one sulfate salt.

Abstract: A method for recovering inorganic salt during processing of a lignocellulosic feedstock is provided. The method comprises pretreating the lignocellulosic feedstock by adding an acid to the feedstock to produce a pretreated lignocellulosic feedstock. A soluble base is then added to the pretreated lignocellulosic feedstock to adjust the pH and produce a neutralized feedstock. The neutralized feedstock is then enzymatically hydrolyzed to produce an enzyme hydrolyzed feedstock and a sugar stream. Inorganic salt is recovered from either a stream obtained from the lignocellulosic feedstock prior to the step of pretreating, a stream obtained from the pretreated lignocellulosic feedstock, a stream obtained from the neutralized feedstock, a stream obtained from the sugar stream, or a combination of these streams. The inorganic salt may be concentrated, clarified, recovered and purified by crystallization, electrodialysis drying, or agglomeration and granulation, and then used as desired, for example as a fertilizer.