The present invention relates to a process of producing isobutanol, including: mixing water, lactate, an enzyme mixture including at least one enzyme, at least one cofactor, and at least one coenzyme, to prepare a reaction mixture; allowing catalytic conversions of lactate in the reaction mixture for a sufficient amount of time to produce isobutanol; and separating the isobutanol from a reactant obtained by the catalytic conversions, in which the conversion of lactate into isobutanol is in association with a NADH.sup.+/NADH and/or NADP.sup.+/NADPH regenerating system.

The biological production of beta-hydroxyisovalerate (HIV) using a non-natural microorganism. The non-natural microorganism for the biologically-derived HIV provides more beta-hydroxyisovalerate synthase activity than the wild-type parent. The non-natural microorganism can host a non-natural enzyme, such as the non-natural enzyme expressed in a yeast or bacteria, wherein the non-natural microorganism comprises an active HIV metabolic pathway for the production of HIV. The biological derivation of HIV eliminates toxic by-products and impurities that result from the chemical production of HIV, such that HIV produced by a non-natural microorganism prior to any isolation or purification process has not been in substantial contact with any halogen-containing component.

Methods and materials related to producing isobutyric acid are disclosed. Specifically, isolated nucleic acids, polypeptides, host cells, methods and materials for producing isobutyric by direct microbial fermentation from a carbon source are disclosed.

A method for producing an ordered protein lattice, the method comprising: (a) providing a first component comprising a subunit of a homooligomeric protein assembly fused to a first subunit of a heterooligomeric protein assembly, and a second component comprising a second subunit of the heterooligomeric protein assembly, wherein the homooligomeric protein assembly and the heterooligomeric protein assembly are each symmetrical in two or three dimensions and share a rotational symmetry axis of the same order; (b) mixing said first monomer and said second monomer to produce a mixture; and (c1) (i) heating the mixture to a temperature about 2 C. to about 10 C. below the visible dissociation temperature; (ii) cooling the mixture by about 10 C. to about 20 C.; and (iii) repeating steps (i) and (ii) at least 10 times; or (c2) (i) heating the mixture to a temperature about 2 C. to about 30 C. or more below the visible dissociation temperature; and (ii) holding the mixture at a temperature about 2 C. to about 30 C. or more below the melt temperature, thereby producing an ordered protein lattice.

The invention relates to recombinant host cells having at least one integrated polynucleotide encoding a polypeptide that catalyzes a step in a pyruvate-utilizing biosynthetic pathway, e.g., pyruvate to acetolactate conversion. The invention also relates to methods of increasing the biosynthetic production of isobutanol, 2,3-butanediol, 2-butanol or 2-butanone using such host cells.

The invention relates to recombinant host cells having at least one integrated polynucleotide encoding a polypeptide that catalyzes a step in a pyruvate-utilizing biosynthetic pathway, e.g., pyruvate to acetolactate conversion. The invention also relates to methods of increasing the biosynthetic production of isobutanol, 2,3-butanediol, 2-butanol or 2-butanone using such host cells.

2-ketoacid decarboxylase enzymes, compositions encoding for 2 ketoacid decarboxylase enzymes, and host cells comprising such enzymes or compositions are provided

Polypeptides having ketol-acid reductoisomerase activity are provided. Also disclosed are recombinant host cells comprising isobutanol biosynthetic pathways employing such polypeptides. Methods for producing isobutanol employing host cells comprising the polypeptides having ketol-acid reductoisomerase activity are also disclosed.

Provided herein, in some aspects, are methods and compositions for producing large-scale quantities of butanol, including normal butanol (n-butanol), isobutanol, and 2-butanol using a cell-free system.

The invention is intended to improve xylose assimilation ability and ethanol fermentation ability in a xylose-assimilating yeast into which a xylose isomerase gene has been introduced. The amount of NADH produced by the recombinant yeast into which the xylose isomerase gene had been introduced as a result of the enzymatic reaction of acetohydroxy acid reductoisomerase is lowered.