Abstract: Nitrogen in a form suitable for feeding a population of microbes in a bioreactor is produced by reacting nitrogen gas and hydrogen gas to form ammonia plus an unreacted gas stream under conditions favorable to having little unreacted nitrogen gas in the unreacted gas stream. The ammonia, or a compound derived from the ammonia is fed to the microbes and the unreacted gas stream is optionally fed back into the reaction, or fed into the bioreactor. Oxygen can be produced, such as by electrolysis, and also provided to the microbes. Hydrogen from the electrolysis can be added to the hydrogen being reacted with nitrogen gas, and/or can be added to the bioreactor. Where nitrogen gas is produced from air separation, the residual gases can be another source of oxygen.

Abstract: A crtW gene from a strain of Brevundimonas is disclosed that encodes a novel ketolase for carotenoid synthesis. An exemplary synthetic operon containing additional relevant carotenoid gene sequences is also provided, where the expression of the synthetic operon is used to produce ketocarotenoids. Suitable DNA expression constructs derived from these sequences are inserted into an expression host for expression. The expression product is a ketolase enzyme that is operable for transforming beta-carotene into canthaxanthin and astaxanthin.

Abstract: Aquafeed, animal feed, and other food products, as well as nutritional and pharmaceutical compounds, chemicals and biomaterials are important commodities that can be produced at commercial scale by fermentation of microorganisms. The present invention provides a method for producing these valuable multi-carbon compounds from simple gas feedstocks, such as carbon dioxide, hydrogen and oxygen, by cultivating a consortium of microbial cells specially selected for this purpose in an aqueous culture medium. In addition to exploiting inexpensive feedstocks, such as waste industrial gas for this cultivation, the platform described herein also provides the advantage of removing carbon dioxide and other waste gases from industrial emissions, which would otherwise contribute to global climate change. Furthermore, the cultivation of a microbial consortium can provide highly nutritious components to a feed blend that might not be available from a monoculture.

Abstract: Systems and methods for employing chemoautotrophic micro-organisms to capture carbon from industrial waste are provided. An exemplary system comprises an industrial source, such as a cement plant, and a bioreactor including the micro-organisms. The bioreactor is fed the waste stream from the source, which provides carbon to the micro-organisms, and is also fed hydrogen, from which the micro-organisms derive their energy. Additional or alternative carbon can be provided from a gasifier fed an organic feedstock. The carbon provided to the micro-organisms is converted into chemical products which can be recovered from the bioreactor. Hydrogen can be produced by electrolysis using electricity generated by a renewable energy source.

Abstract: Bioreactors comprising an electrical stimulation system supply a pulsed and/or modulated electrical input to microbes that use the electrical stimulation and available CO2 to produce valuable organic compounds. Electrical power, such as from renewable sources remotely located with respect to the power grid, can be converted to chemical energy in the form of the organic compounds, which can be stored and/or transported readily.

Abstract: Microbial fuel cells including multiple electrodes, and systems of such fuel cells, are provided. An exemplary fuel cell includes a population of exoelectrogenic microbes and at least two anodes in an anode chamber, and a cathode in a cathode chamber. A path exists between the chambers for conducting hydrogen ions and each anode is connected to the cathode by a separate external circuit. Electrical output from the fuel cell is maximized by optimizing the microbe population, achieved by dynamically controlling the sub-populations at each of the multiple anodes. Systems comprising multiple such fuel cells connected by a dynamically reconfigurable fluidics system provide further optimization.

Abstract: Microbial fuel cells including multiple electrodes, and systems of such fuel cells, are provided. An exemplary fuel cell includes a population of exoelectrogenic microbes and at least two anodes in an anode chamber, and a cathode in a cathode chamber. A path exists between the chambers for conducting hydrogen ions and each anode is connected to the cathode by a separate external circuit. Electrical output from the fuel cell is maximized by optimizing the microbe population, achieved by dynamically controlling the sub-populations at each of the multiple anodes. Systems comprising multiple such fuel cells connected by a dynamically reconfigurable fluidics system provide further optimization.