Abstract: Processes for the bioconversion of syngas to oxygenated organic compound are disclosed that reliably, cost-effectively and efficiently supply sulfur nutrient to microorganisms contained in acidic, aqueous fermentation menstrua. In the processes of this invention, basic, aqueous solution used to maintain the pH of the aqueous fermentation menstruum is used to remove hydrogen sulfide from the off-gas from the fermentation menstruum for recycle to the fermentation menstruum.

Abstract: Methods are disclosed for controlling the population of acetoclastic microorganisms in a process for the bioconversion of gas substrate comprising at least one of CO and a mixture of CO2 and hydrogen to at least one oxygenated organic compound by contact of said gas substrate under acidic, anaerobic fermentation conditions in a bioreactor containing an aqueous fermentation broth having a population of at least one acetogenic microorganism for bioconverting said gas substrate to at least one acetogenic oxygenated organic compound, said fermentation zone defining a head space, said methods comprising continuously or intermittently controlling the partial pressure of carbon dioxide in the head space to provide a desired population ratio of acetoclastic microorganisms to acetogenic microorganisms.

Abstract: High conversion efficiency processes are disclosed for the anaerobic bioconversion of syngas to alcohol by microorganisms having metabolic processes that utilize sulfur in limited amounts. The processes remove hydrogen sulfide from the gas leaving the bioreactor assembly by forming sulfur compounds that are beneficial to the microorganisms. The sulfur compounds can be returned to the bioreactor assembly to meet a portion of microorganism sulfur demand.

Abstract: Integrated processes are provided for the bioconversion of syngas to oxygenated organic compound with the ability to recycle sulfur nutrient and generate sulfur nutrient to the syngas fermentation in a safe and cost-effective manner. In preferred aspects of the invention, an acidogenic digestion is used to provide a biogas containing hydrogen sulfide, and then a methanogenic fermentation can follow to provide a methane-containing biogas that has a low hydrogen sulfide concentration.

Abstract: This invention provides isolated polynucleotides encoding DNA Type I methyltransferase and uses thereof for improving transformation efficiencies of exogenous and endogenous plasmid DNA into Clostridial hosts.

Abstract: Gene sequences of key acetogenic clostridial species were sequenced and isolated. Genes of interest were identified, and functionality was established. Key genes of interest for metabolic catalyzing activity in clostridial species include a three-gene operon coding for CODH activity, a two-gene operon coding for PTA-ACK, and a novel acetyl coenzyme A reductase. The promoter regions of the two operons and the acetyl coA reductase are manipulated to increase ethanol production.

Abstract: A method of operating a fermentation zone for the production of ethanol from syngas uses a crotonate-like compound to prevent or reverse the effects of butyrogen contamination. The crotonate-like compound works in continuous fermentation processes to reduce or eliminate contamination from butyrate and butanol in the syngas derived ethanol product.

Abstract: Processes are disclosed for the anaerobic bioconversion of syngas to oxygenated organic compound that use an in situ method for protecting the microorganisms from hydrogen cyanide contained in the syngas that passes to the fermentation broth. The fermentation broth is maintained at a pH of between about 4 and 6, and dissolved metal cation of one or more of iron, cobalt, nickel and zinc is provided to the fermentation broth in an amount sufficient to form, under the conditions of the fermentation broth, a substantially insoluble metal complex with the metal cation and cyanide anion. The rate of formation of the insoluble complex is sufficiently high that that the amount of cyanide that is taken up by microorganisms does not result in an undue adverse effect on the population of microorganisms.

Abstract: Processes are disclosed for the low energy, anaerobic bioconversion of hydrogen and carbon monoxide in a gaseous substrate stream to oxygenated organic compounds such as ethanol by contact with microorganisms in a deep, tank fermentation system with high conversion efficiency of both hydrogen and carbon monoxide. Gas feed to the reactor is injected using a motive liquid to form a stable dispersion of microbubbles thereby reducing energy costs, and a portion of the off-gases from the reactor are recycled to (i) achieve a conversion of the total moles of carbon monoxide and hydrogen in the gas substrate to oxygenated organic compound of at least about 80 percent and (ii) attenuate the risk of carbon monoxide inhibition of the microorganism used for the bioconversion.

Abstract: Integrated processes are provided for the bioconversion of syngas to oxygenated organic compound with the ability to recover essential compounds for the fermentation and recycle the compounds to the fermentation.

Abstract: Integrated processes are provided for syngas refining and bioconversion of syngas to oxygenated organic compound. In the integrated processes ammonia contained in the syngas is recovered and used as a source of nitrogen and water for the fermentation. The integrated processes first remove tars from syngas by scrubbing using a first aqueous medium under conditions that ammonium bicarbonate is unstable. With tars removed, contact between the syngas and a second aqueous medium enables ammonia and carbon dioxide to be removed from the syngas without undue removal of components adverse to the fermentation, processing or oxygenated product such as benzene, toluene, xylene, ethylene, acetylene, and hydrogen cyanide. At least a portion of the second aqueous medium is supplied as a source of water and ammonia for the fermentation.

Abstract: Essential genes coding for the metabolic pathway of solventogenic autotrophic Clostridia were sequenced, and functionality was confirmed. The present invention utilizes a comparative inter-species approach to develop the minimum set of essential genes for metabolic function and estimate productivity in species of suspected solventogenic capability.

Abstract: Processes are disclosed for the low energy, anaerobic bioconversion of hydrogen and carbon monoxide in a gaseous substrate stream to oxygenated organic compounds such as ethanol by contact with microorganisms in a fermentation system with high conversion efficiency of both hydrogen and carbon monoxide. The processes of this invention use a pre-reactor and a deep, tank reactor in gaseous substrate flow sequence to obtain high conversion of gas substrate without undue risk of carbon monoxide inhibition.

Abstract: This invention pertains to processes for selectively oxidizing hydrogen cyanide contained in syngas using permanganate anion as an oxidant contained in an aqueous solution that is contacted with the syngas under certain conditions of temperature, pressure and duration of contact.

Abstract: Processes for starting up of anaerobic, deep tank fermentation systems to anaerobically bioconvert hydrogen and carbon monoxide in a gaseous substrate stream to oxygenated organic compounds and for steady operation of such fermentation systems. In the processes injectors use a motive liquid to introduce gas substrate as a stable gas-in liquid dispersion into the deep tank fermentation reactor where at least one of: (i) adjusting the gas to liquid flow ratio through an injector, (ii) changing the rate of liquid flow through an injector, and (iii) adjusting the carbon monoxide mole fraction in the gas feed by admixture with at least one other gas, wherein the mass transfer of carbon monoxide to an aqueous menstruum in the reactor is controlled to obtain the robust growth of the microorganism and/or continued conversion of gas substrate while maintaining the carbon monoxide concentration below that amount which is unduly adverse to the microorganism.

Abstract: Processes are disclosed for the conversion of biomass to oxygenated organic compound using a simplified syngas cleanup operation that is cost effective and protects the fermentation operation. The processes of this invention treat the crude syngas from the gasifier by non-catalytic partial oxidation. The partial oxidation reduces the hydrocarbon content of the syngas such as methane, ethylene and acetylene to provide advantageous gas feeds for anaerobic fermentations to produce oxygenated organic compounds such as ethanol, propanol and butanol. Additionally, the partial oxidation facilitates any additional cleanup of the syngas as may be required for the anaerobic fermentation. Producer gases and partial oxidation processes are also disclosed.

Abstract: Processes are provided for starting up of anaerobic, deep tank fermentation systems used in the anaerobic bioconversion of hydrogen and carbon monoxide in a gaseous substrate stream to oxygenated organic compounds such as ethanol. In the processes injectors using a motive liquid are used to introduce gas substrate into the deep tank fermentation reactor where at least one of: (i) adjusting the gas to liquid flow ratio through an injector, (ii) changing the rate of liquid flow through an injector, and (iii) adjusting the carbon monoxide mole fraction in the gas feed by admixture with at least one other gas, wherein the mass transfer of carbon monoxide to an aqueous menstruum in the reactor is controlled to obtain the robust growth of the microorganism while maintaining the carbon monoxide concentration below that amount which is unduly adverse to the microorganism.

Abstract: Processes are disclosed for the conversion of biomass to oxygenated organic compound using a simplified syngas cleanup operation that is cost effective and protects the fermentation operation. The processes of this invention treat the crude syngas from the gasifier by non-catalytic partial oxidation. The partial oxidation reduces the hydrocarbon content of the syngas such as methane, ethylene and acetylene to provide advantageous gas feeds for anaerobic fermentations to produce oxygenated organic compounds such as ethanol, propanol and butanol. Additionally, the partial oxidation facilitates any additional cleanup of the syngas as may be required for the anaerobic fermentation. Producer gases and partial oxidation processes are also disclosed.

Abstract: High conversion efficiency processes are disclosed for the anaerobic bioconversion of syngas to alcohol by microorganisms having metabolic processes that utilize sulfur in limited amounts. The processes remove hydrogen sulfide from the gas leaving the bioreactor assembly by forming sulfur compounds that are beneficial to the microorganisms. The sulfur compounds can be returned to the bioreactor assembly to meet a portion of microorganism sulfur demand.

Abstract: Processes are disclosed for the anaerobic bioconversion of syngas to oxygenated organic compound that use an in situ method for protecting the microorganisms from hydrogen cyanide contained in the syngas that passes to the fermentation broth. The fermentation broth is maintained at a pH of between about 4 and 6, and dissolved metal cation of one or more of iron, cobalt, nickel and zinc is provided to the fermentation broth in an amount sufficient to form, under the conditions of the fermentation broth, a substantially insoluble metal complex with the metal cation and cyanide anion. The rate of formation of the insoluble complex is sufficiently high that that the amount of cyanide that is taken up by microorganisms does not result in an undue adverse effect on the population of microorganisms.