What is disclosed is a biorefining process to co-produce xylitol with ethanol or other products. In some variations, a process for producing ethanol and xylitol from lignocellulosic biomass, comprises: extracting hemicelluloses from lignocellulosic biomass, wherein the hemicelluloses include xylose oligomers and other sugar oligomers; hydrolyzing the xylose oligomers and the other sugar oligomers, using an acid catalyst or enzymes, to generate xylose and other sugar monomers, respectively; fermenting the other sugar monomers to ethanol using a suitable ethanol-producing microorganism; removing at least some of the ethanol (to increase concentration of xylose); fermenting the xylose to xylitol using a suitable xylitol-producing microorganism; and recovering the xylitol at high concentration.

Methods of using thermostable serine proteases are described herein.

The present invention relates to a process for treating a lignocellulosic biomass pretreated beforehand (1), said process comprising the extraction of the free sugars from said pretreated biomass using an alcoholic or aqueous-alcoholic extraction solution (2), so as to obtain a liquid phase enriched in free sugars, called liquor (3), and a solid phase depleted in free sugars, called must (4).

The present disclosure provides methods for generating sugars from a cellulosic biomass. The methods combine treatment of the biomass using a high-shear milling device and saccharification of the biomass to partially hydrolyze the biomass. The biomass can be saccharified either after or simultaneously with the high-shear milling treatment. The partially hydrolyzed biomass is then separated into a solids stream with saccharification enzymes, and a liquid stream with sugars. The solids stream and associated enzymes are further incubated under saccharification conditions to produce additional sugars, or are recycled and added to fresh biomass, which is saccharified under high-shear milling conditions. The methods result in improved conversion of cellulosic biomass to glucose.

This disclosure describes processes for using a single cellulosic feedstock or a combination of two or more different cellulosic feedstocks with a starch component to produce a fermented product. The process includes separating the components of the cellulosic feedstocks with fractionation, pretreating a component with wet fractionation with chemicals, hydrolysis and fermentation of the pretreated feedstock(s) to produce cellulosic biofuel. The process may include combining the cellulosic feedstock(s) with other components to a cook and/or a fermentation process, distilling and dehydrating the combined components to produce the bio fuel. The process may also include producing a whole stillage stream from the feedstock(s) and mechanically processing the whole stillage stream to produce a high-value protein animal feed.

Disclosed herein are processes for ethanol production from a lignocellulosic feedstock. These processes provide DMR of lignocellulosic biomass comprising two-stage deacetylation followed by mechanical refining so as to increase fermentable sugar yield while reducing hydrolytic enzyme loading requirements.

The present disclosure relates to processes for producing hydrocarbon fuels from lignocellulosic biomass. A process may include introducing biomass to a pretreatment system, and a first separation system forming a pentose-rich stream and a pentose-lean stream. The pentose-lean stream may be introduced to a hydrolysis system forming a hydrolysate and the hydrolysate introduced to a second separation system forming a hexose-rich stream and a lignin stream. Additionally, at least one of the pentose-rich stream or the hexose-rich stream may be introduced to a bioreactor containing microorganisms configured to produce hydrocarbon fuels. Additionally, the present disclosure also relates to systems for the production of hydrocarbon fuels. A system may include a pretreatment system, a first separation system, a hydrolysis system, a second separation system, and one or more bioreactors. Alternatively a system may include a pretreatment system, a hydrolysis system, a sugar separation system, and one or more bioreactors.

Disclosed are methods for the pre-treatment of lignocellulose by adding an alkali or acid reagent(s) during the densification thereof, and for the biotransformation thereof. In the method, an alkali reagent(s) or acid reagent(s) is added to a lignocellulosic raw material for a densification pre-treatment to form an alkali- or acid-containing densified lignocellulose with a compressed compact shape, thereby achieving the pre-treatment. The acid or alkali in the pre-treated lignocellulose can further pre-treat the lignocellulosic raw material in a mild manner during the subsequent transportation and storage processes. If a subsequent pre-treatment is needed, then the severity thereof is reduced substantially; in addition, the uniform mixing of the acid or alkali with the lignocellulose and a large density of the raw material promote a high efficiency and a high loading capacity of the subsequent pre-treatment of the densified lignocellulose. The method is simple and efficient. The resulting lignocellulosic raw material has a large density, will not easily degrade or rot due to the inclusion of an acid or alkali, which is conducive to transportation and storage, and a high equipment utilization rate during the subsequent treatment is achieved.

An improved dry grind system and method for producing a sugar stream from grains or similar carbohydrate sources and/or residues, such as for biofuel production. In particular, a sugar/carbohydrate stream, which includes a desired Dextrose Equivalent (DE) where DE describes the degree of conversion of starch to dextrose (aka glucose) and/or has had removed therefrom an undesirable amount of unfermentable components, can be produced after saccharification and prior to fermentation (or other sugar conversion process), with such sugar stream being available for biofuel production, e.g., alcohol production, or other processes. In addition, the systems and methods also can involve the removal of certain grain components, e.g., corn kernel components, including protein, oil and/or fiber, prior to fermentation or other conversion systems. In other words, sugar stream production and/or grain component separation occurs on the front end of the system and method.

The present invention concerns an oleaginous yeast variant of the species Rhodosporidium azoricum characterized by higher biomass yields and intra- cellular lipid accumulation useful for the production of bio-fuels higher, in determined conditions, with respect to the wild type strain of the same species. Furthermore, the invention concerns a method through which said oleaginous yeast variant of the species Rhodosporidium azoricum was obtained. The invention further concerns the lipid production by means of said variant strain of oleaginous yeast of the species Rhodosporidium azoricum.