Processes for starting up and operating anaerobic, deep tank fermentation reactors including a process for anaerobic bioconversion of a gas substrate comprising carbon monoxide, hydrogen, and carbon dioxide in a reactor by contact of the gas substrate with an aqueous menstruum containing microorganisms suitable for converting the gas substrate to an oxygenated organic compound in the reactor. The process further includes: blanketing the reactor above the aqueous menstruum to the essential exclusion of oxygen with a head space gas comprising at least one of carbon monoxide, hydrogen, carbon dioxide, nitrogen, and a lower alkane; continuously supplying a feed gas comprising at least a portion of the gas substrate to the aqueous menstruum in the reactor; and injecting the gas substrate and a motive liquid into the reactor to form a dispersion of the motive liquid and microbubbles, the microbubbles having a diameter of less than about 500 microns.

The present invention relates to isolated polypeptides having beta-xylosidase 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.

Process for extracting volatile fatty acids (VFA), organic molecules called precursors produced by microorganisms (M) in a fermentation reactor (2) by anaerobic fermentation (3) using fermentable biomass (1), said molecules being fermentative metabolites, comprising at least the following steps: a) selecting an extraction means (8) from extraction means that is, at least, insoluble in the fermentation medium and the processing conditions of which preserve the capacity of the microorganisms (M) present in the fermentation medium to produce the molecules, b) bringing the chosen extraction means (8) into contact (9) with the fermentation medium without interrupting the fermentation (3), c) recovering (12) the extracted molecules, at a pH lower than 4.5, by the extraction means (8) outside the fermentation reactor (2).

The invention also relates to an installation for implementing the method.

Biomass feedstocks (e.g., plant biomass, animal biomass, and municipal waste biomass) are processed to produce useful products, such as fuels. For example, systems are described that can convert feedstock materials to a sugar solution, which can then be fermented to produce ethanol. Biomass feedstock is saccharified in a vessel by operation of a jet mixer, the vessel also containing a liquid medium and a saccharifying agent.

Biomass feedstocks (e.g., plant biomass, animal biomass, and municipal waste biomass) are processed to produce useful products, such as fuels. For example, systems are described that can convert feedstock materials to a sugar solution, which can then be fermented to produce ethanol. Biomass feedstock is saccharified in a vessel by operation of a jet mixer, the vessel also containing a liquid medium and a saccharifying agent.

Genetically engineered bacteria, pharmaceutical compositions thereof, and methods of modulating and treating disorders associated with hyperammonemia are disclosed.

The disclosure relates to engineered enone reductase polypeptides having improved properties, polynucleotides encoding the engineered polypeptides, related vectors, host cells, and methods for making the engineered enone reductase polypeptides. The disclosure also provides methods of using the engineered enone reductase polypeptides for chemical transformations.

A process for manufacturing purified glycerol including the steps of providing a starting glycerol fraction comprising glycerol, water, and fatty acid methyl esters, subjecting the glycerol fraction to a partial evaporation to form an evaporated fraction including glycerol, water, and fatty acid methyl esters, and a remainder fraction including glycerol, condensing the evaporated fraction to form a liquid, subjecting the liquid evaporated fraction including glycerol, water, and fatty acid methyl esters to a liquid-liquid separation step, resulting in the formation of a fatty acid methyl ester fraction and a glycerol-based fraction including glycerol and water. The process makes it possible to efficiently separate the fatty acid methyl esters from glycerol, without the need for complete glycerol distillation. Also provides glycerol fractions suitable for use as carbon source in fermentation processes, without problems in down-stream processing, and without the need for cost-intensive purification steps for the glycerol.

A process for manufacturing purified glycerol including the steps of providing a starting glycerol fraction comprising glycerol, water, and fatty acid methyl esters, subjecting the glycerol fraction to a partial evaporation to form an evaporated fraction including glycerol, water, and fatty acid methyl esters, and a remainder fraction including glycerol, condensing the evaporated fraction to form a liquid, subjecting the liquid evaporated fraction including glycerol, water, and fatty acid methyl esters to a liquid-liquid separation step, resulting in the formation of a fatty acid methyl ester fraction and a glycerol-based fraction including glycerol and water. The process makes it possible to efficiently separate the fatty acid methyl esters from glycerol, without the need for complete glycerol distillation. Also provides glycerol fractions suitable for use as carbon source in fermentation processes, without problems in down-stream processing, and without the need for cost-intensive purification steps for the glycerol.

Provided herein are methods for processing biomass materials that are disposed in one or more structures or carriers, e.g., a bag, a shell, a net, a membrane, a mesh or any combination of these. Containing the material in this manner allows it to be readily added or removed at any point and in any sequence during processing.