Dartmouth College

Ut-battelle, Inc.

Michigan State University

Lallemand Hungary Liquidity Management LLC

Paye, Julie, M.d.

Lynd, Lee R.

Lee R Lynd

David Anthony Hogsett

Xiongjun Shao

Bruce E Dale

John E McBride

Arthur J Shaw, Iv

Adam Michael Guss

Ramesh R Bhave

Kristen M Deleault

Hans E Grethlein

Daniel G Olson

Steven D Brown

Shihui Yang

John Bardsley

Colin R South

Gisbert Spieles

Mark Laser

Tatiana Karpinets

Kara Podkaminer

Sunil G Desai

Michael Balch

Julie M D Paye

Aysenur Eminoglu

Julie Paye

Disclosed are methods for engineering bacteria, for example,, that convert biomass to ethanol at high yield by deleting a single gene. Deletion of subunit A or subunit B of the hfs hydrogenase, but not deletion of subunit C or subunit D, results in an increase in ethanol yield.

Increased ethanol production by thermophilic microorganisms with deletion of individual hfs hydrogenase subunits

A system and method for converting biomass with no chemical pretreatment is disclosed. Combination of a microbial system and the use of mechanical disruption during fermentation may help achieve high conversion rate without the extra cost and undesirable by-products typically associated with the pretreatment process.

Systems and methods for enhancing microbial conversion of biomass using mechanical augmentation

Mutant thermophilic organisms that consume a variety of biomass derived substrates are disclosed herein. Strains ofwith acetate kinase and phosphotransacetylase expression eliminated are disclosed herein. Further, strain ALK1 has been engineered by site directed homologous recombination to knockout both acetic acid and lactic acid production. Continuous culture involving a substrate concentration challenge lead to evolution of ALK1, and formation of a more robust strain designated ALK2. The organisms may be utilized for example in thermophilic SSF and SSCF reactions performed at temperatures that are optimal for cellulase activity to produce near theoretical ethanol yields without expressing pyruvate decarboxylase.

Thermophilic organisms for conversion of lignocellulosic biomass to ethanol

The present invention is directed to the construction of prototrophic, cellulo lytic strains ofwith tethered and secreted cellulases and selection-based improvement of growth on cellulose by these strains. In some embodiments, host cells of the invention are able to produce ethanol using crystalline cellulose as a sole carbon source.

Construction of protrophic/celluloytic yeast strains expressing tethered and secreted cellulases

A process for the pretreatment of lignocellulosic biomass is provided. The process generally includes flowing water through a pretreatment reactor containing a bed of particulate ligno-cellulosic biomass to produce a pressurized, high-temperature hydrolyzate exit stream, separating solubilized compounds from the hydrolyzate exit stream using an inorganic nanoporous membrane element, fractionating the retentate enriched in solubilized organic components and recycling the permeate to the pretreatment reactor. The pretreatment process provides solubilized organics in concentrated form for the subsequent conversion into biofuels and other chemicals.

Flow-through pretreatment of lignocellulosic biomass with inorganic nanoporous membranes

The present invention provides isolated nucleic acid molecules which encode a mutant acetaldehyde-CoA/alcohol dehydrogenase or mutant alcohol dehydrogenase and confer enhanced tolerance to ethanol. The invention also provides related expression vectors, genetically engineered microorganisms having enhanced tolerance to ethanol, as well as methods of making and using such genetically modified microorganisms for production of biofuels based on fermentation of biomass materials.

Nucleic acid molecules conferring enhanced ethanol tolerance and microorganisms having enhanced tolerance to ethanol

A process for the treatment of biomass to render structural carbohydrates more accessible and/or digestible using concentrated ammonium hydroxide with or without anhydrous ammonia addition, is described. The process preferably uses steam to strip ammonia from the biomass for recycling. The process yields of monosaccharides from the structural carbohydrates are good, particularly as measured by the enzymatic hydrolysis of the structural carbohydrates. The monosaccharides are used as animal feeds and energy sources for ethanol production.

Process for the treatment of lignocellulosic biomass

An improved continuous process for producing ethanol from cellulosic materials employs an intermittently agitated, perpetually fed, solids retaining reactor vessel. Cellulosic substrate, catalysts and fermentation agents are introduced into a reaction vessel to form a slurry. The slurry is agitated for a first selected time interval under conditions sufficient to initiate and maintain a fermentation reaction and then allowed to settle during a second selected time interval. At the end of the second selected time interval an ethanol-containing effluent is removed from the vessel. Thereafter, additional cellulosic material, catalysts and fermentation agents are added to the reactor vessel. This operating cycle is repeated virtually perpetually to effect the ethanol production. It can be implemented using a single bioreactor or a cascade of bioreactors.

Continuous process for making ethanol

An improved and highly productive method of continuously producing ethanol from lignocellulosic substrates is provided. The method involves providing a suitable microbial system within a reaction vessel and adding fermentable substrate to the reactor to form a reaction mixture. The fermentation reaction is allowed to proceed while a quiescent state is maintained within the reactor. During the fermentation, soluble substrate is differentially retained relative to the feed slurry and reaction biocatalysts are retained and internally recycled within the system. Further, while fermenting substrate is retained within the system, it forms a stratified zone within the reactor such that the concentration of actively fermenting substrate is highest at upper portions of the reaction zone and is lowest, near zero, at a lower portion of the reaction zone. Insoluble, fully reacted substrate may be withdrawn from a region near the bottom of the reactor.

Continuous process for ethanol production from lignocellulosic materials

A method of distillation employing a heat pump (which may be driven by a compressor) using a vapor stream from within the distillation system as a heat source and a liquid stream from within the distillation system as a heat sink. The selection of heat-source vapors and heat-sink liquid is such that at least one is withdrawn from the phase-contracting region of the distillation system. The return of streams withdrawn from the phase-contacting region of the distillation system to the distillation system is such that at least one of the streams is returned at a temperature different from that of the point from which it was withdrawn, and all withdrawn streams are returned in manner such that a stream removed as vapor is returned at a point with a temperature at most that at the point it was withdrawn, and a stream removed as liquid is returned at a point with a temperature at least that at which it was withdrawn. Embodiments of the basic method where vapor only, liquid only, or both liquid and vapor are withdrawn from and returned to the phase-contacting region of the distillation system are considered. The impact of the invention is to reduce the heat requirement of distillation in exchange for an amount of work which is usually small because the temperature difference between heat sources and sinks is minimized. Combination of the basic distillation method with multi-effect distillation, convention overhead-to-reboiler heat pumped distillation, azeotropic and extractive distillation, and fermentative production of volatile compounds is described. A system specifically designed for the separation of ethanol-water mixtures which utilizes the present invention and extractive distillation in a system with extensive heat integration is presented.

Distillation process for ethanol

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Meriden, NH, United States of America

Lee R Lynd