A method for pretreating a wood dust includes conducting a structurally damaged step and an alkali treatment step. In the structurally damaged step, the wood dust is disposed in a scCO.sub.2 atmosphere with a pressure of 2600 psi to 3400 psi at a temperature of 40° C. to 120° C. for a predetermined time, and then the pressure is adjusted to drop to an atmospheric pressure in a sudden manner to obtain a structurally damaged wood dust. In the alkali treatment step, the structurally damaged wood dust is immersed in an alkaline H.sub.2O.sub.2 solution at a temperature of 50° C. to 70° C., a concentration of H.sub.2O.sub.2 in the alkaline hydrogen peroxide solution is in a range of 0.1 wt % to 2.1 wt %, and a pH value of the alkaline H.sub.2O.sub.2 solution is in a range of 10.5 to 12. Thus a treated wood dust is obtained.

The invention relates to processes for the conversion of biomass into carbohydrates, notable fermentable sugars. It provides means and methods for increasing the yield of enzymatic digestion of a biomass, in particular in those cases where cellulose is converted into sugars using a cellulose converting enzyme. More in particular, the invention relates to a method for producing a fermentable sugar from a lignocellulosic material wherein the lignocellulosic material is contacted with a laccase and an enzyme capable of degrading cellulose, either simultaneously or in a sequentially deferred fashion, wherein the laccase is the Bacillus spore coat protein CotA.

There is provided an additive for a bioethanol fermentation process comprising a polyoxyalkylene compound (A) having a Griffin's HLB value in the range of 0 to 6, a polyoxyalkylene polyol (B) and a base oil (C) that is liquid at 25° C. The compound (A) is preferably a mixture of a compound represented by a general formula (1) and a compound represented by a general formula (2). In the formula, R.sup.1 and R.sup.3 represent alkyl or alkenyl, R.sup.2 and R.sup.4 represent a hydrogen atom or a monovalent organic group, AO represents oxyalkylene having a carbon number of 3 to 18, a reaction residue of glycidol, a reaction residue of an alkyl glycidyl ether or a reaction residue of an alkenyl glycidyl ether, EO represents oxyethylene, m and n are 1 to 100, and p is 3 to 10.

R.sup.1O-(AO).sub.m—R.sup.2  (1)

R.sup.3O-(AO).sub.n-(EO).sub.p—R.sup.4  (2)

The present invention relates to variants of a parent alpha-amylase. The present invention also relates to polynucleotides encoding the variants and to nucleic acid constructs, vectors, and host cells comprising the polynucleotides, and methods of using the variant enzymes.

A process to prepare propionic acid comprises preparing a fermentation broth of water; at least 30 weight percent hydrolyzed corn mash solids, hydrolyzed sugar cane mash solids, or a combination thereof, based on the combined weight of the fermentation broth as a whole; and propionibacteria; without including the typical, frequently very costly supplementation with vitamin and mineral packages. Surprisingly, these mash solids, which must often be disposed of following syrup production, are capable of supplying the nitrogen, micronutrients, vitamins and minerals known to be needed for propionibacteria fermentation, making their sole or significant use as fermentation mediums far more economical and therefore desirable than other fermentation mediums which require supplementation.

This invention provides optimized fermentation of cellulosic and hemicellulosic sugars. Biomass-derived hemicellulosic and cellulosic sugars are independently conditioned and separately fermented, utilizing reuse and recycle of microorganisms, metabolic intermediates, and nutrients. Conditioned sugars can be fermented in separate vessels, where excess cells from glucose fermentation are conveyed to hemicellulose sugar fermentation along with raffinate from solvent recovery, to enhance productivity and product yield. Some variations provide a method of fermenting C.sub.5 and C.sub.6 sugars to fermentation products, the method comprising: fermenting a C.sub.6-rich sugar feed to a first fermentation product; fermenting a C.sub.5-rich sugar feed to a second fermentation product; removing microorganism cells from the first fermentor, to maintain a cell concentration within a selected range; conveying microorganism cells to a second fermentor; and removing microorganism cells from the second fermentor, to maintain a microorganism cell concentration that is greater than that in the C.sub.6-rich fermentor.

A method is provided for the production of alcohol from trees, the method comprising a step of treating a subject tree with mother cell lyases formed through cytolysis associated with sporulation of spore-forming aerobic bacteria, thereby degrading said tree into a powdery state and obtaining a tree degradation product; a step of sterilizing said tree degradation product; a step of treating said sterilized tree degradation product with a koji fungus (Aspergillus oryzae) thereby carrying out a primary fermentation; a step of adding a yeast to the fermentation broth obtained by said primary fermentation thereby carrying out a secondary fermentation; and a step of filtering the fermentation broth obtained by said secondary fermentation, wherein said mother cell lyases are obtained by culturing said spore-forming aerobic bacteria, subjecting the resultant culture medium to a starvation state, thereby converting said bacteria into endospores, and removing impurities including said endosporic bacteria from said culture medium and wherein said spore-forming aerobic bacteria are MRE symbiotic bacteria.

The present invention relates to cellobiohydrolase variants and carbohydrate binding module variants. The present invention also relates to polynucleotides encoding the variants; nucleic acid constructs, vectors, and host cells comprising the polynucleotides; and methods of using the variants.

Processes disclosed are capable of converting biomass into high-crystallinity, hydrophobic cellulose. In some variations, the process includes fractionating biomass with an acid (such as sulfur dioxide), a solvent (such as ethanol), and water, to generate cellulose-rich solids and a liquid containing hemicellulose and lignin; and depositing lignin onto cellulose fibers to produce lignin-coated cellulose materials (such as dissolving pulp). The crystallinity of the cellulose material may be 80% or higher, translating into good reinforcing properties for composites. Optionally, sugars derived from amorphous cellulose and hemicellulose may be separately fermented, such as to monomers for various polymers. These polymers may be combined with the hydrophobic cellulose to form completely renewable composites.

The present invention relates to isolated polypeptides having cellobiohydrolase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.