Chemically defined culture medium and culture conditions that allow bacteria to assimilate dinitrogen gas (N.sub.2) as a nitrogen source during bio-ethanol production are disclosed herein. Methods of bioethanol production using the chemically defined culture medium and culture conditions are also disclosed.

Chemically defined culture medium and culture conditions that allow bacteria to assimilate dinitrogen gas (N.sub.2) as a nitrogen source during bio-ethanol production are disclosed herein. Methods of bioethanol production using the chemically defined culture medium and culture conditions are also disclosed.

Microorganisms and methods of producing n-butyraldehyde with enhanced yields are presented in which a microorganism is engineered to enhance the conversion of a carbon source into n-butyraldehyde. The n-butyraldehyde is recovered by way of a gas stripping process that occurs during the conversion process, providing significantly greater product yield than post-fermentation recovery of n-butyraldehyde alone.

Microorganisms and methods of producing n-butyraldehyde with enhanced yields are presented in which a microorganism is engineered to enhance the conversion of a carbon source into n-butyraldehyde. The n-butyraldehyde is recovered by way of a gas stripping process that occurs during the conversion process, providing significantly greater product yield than post-fermentation recovery of n-butyraldehyde alone.

Embodiments provide a modified microbe capable of growing in or fermenting a solution, or lignocellulosic hydrolysate, comprising ferulic acid and/or coniferyl aldehyde. The microbe has one or more modifications to provide: (a) a decrease in copy number or expression of a BNA7 gene; (b) an increase in copy number or expression of one or more pentose phosphate pathway genes; and/or (c) localization of one or more products of the pentose phosphate pathway genes to the mitochondria or endoplasmic reticulum. Also provided is a microbe having modified expression or copy number of BNA7 and/or one or more of the pentose phosphate pathway genes. The pentose phosphate pathway genes may in certain embodiments be selected from at least one of ZWF1, TKL1, RPE1 and GND1. Also provided is a method for fermenting a substrate comprising ferulic acid and/or coniferyl aldehyde to produce a fermentation product.

The present disclosure identifies pathways, mechanisms, systems and methods to confer chemoautotrophic production of carbon-based products of interest, such as sugars, alcohols, chemicals, amino acids, polymers, fatty acids and their derivatives, hydrocarbons, isoprenoids, and intermediates thereof, in organisms such that these organisms efficiently convert inorganic carbon to organic carbon-based products of interest using inorganic energy, such as formate, and in particular the use of organisms for the commercial production of various carbon-based products of interest.

The present disclosure identifies pathways, mechanisms, systems and methods to confer chemoautotrophic production of carbon-based products of interest, such as sugars, alcohols, chemicals, amino acids, polymers, fatty acids and their derivatives, hydrocarbons, isoprenoids, and intermediates thereof, in organisms such that these organisms efficiently convert inorganic carbon to organic carbon-based products of interest using inorganic energy, such as formate, and in particular the use of organisms for the commercial production of various carbon-based products of interest.

A transformant obtained by introducing a DNA of (a1), (a2), or (a3) below, and (b) an alcohol dehydrogenase gene, into a bacterium of the genus Hydrogenophilus, can efficiently produce isobutanol utilizing carbon dioxide as a sole carbon source. (a1) DNA which consists of a base sequence of SEQ ID NO: 1; (a2) DNA which consists of a base sequence having 90% or more identity with SEQ ID NO: 1, the DNA encoding a polypeptide having 2-keto-acid decarboxylase activity; (a3) DNA which hybridizes with a DNA consisting of a base sequence complementary to SEQ ID NO: 1 under stringent conditions, and which encodes a polypeptide having 2-keto-acid decarboxylase activity.

A transformant obtained by introducing a DNA of (a1), (a2), or (a3) below, and (b) an alcohol dehydrogenase gene, into a bacterium of the genus Hydrogenophilus, can efficiently produce isobutanol utilizing carbon dioxide as a sole carbon source. (a1) DNA which consists of a base sequence of SEQ ID NO: 1; (a2) DNA which consists of a base sequence having 90% or more identity with SEQ ID NO: 1, the DNA encoding a polypeptide having 2-keto-acid decarboxylase activity; (a3) DNA which hybridizes with a DNA consisting of a base sequence complementary to SEQ ID NO: 1 under stringent conditions, and which encodes a polypeptide having 2-keto-acid decarboxylase activity.

The present invention relates to novel nucleic acid sequences encoding bacterial xylose isomerases that upon transformation of a eukaryotic microbial host cell, such as yeast, to confer to the host cell the ability of isomerising xylose to xylulose. The nucleic acid sequences encode xylose isomerases that originate from bacteria such as Eubacterium sp., Clostridium cellulosi and others. The invention further relates to fermentation processes wherein the transformed host cells ferment a xylose-containing medium to produce ethanol or other fermentation products.