Recombinant microorganisms and uses therefor

Inventors

Liew, Fungmin • Koepke, Michael

Assignees

Lanzatech Inc

Abstract

Microorganisms are genetically engineered to produce 3-hydroxypropionate (3-HP). The microorganisms are carboxydotrophic acetogens. The microorganisms produce acetyl-coA using the Wood-Ljungdahl pathway for fixing CO/CO2. A β-alanine pyruvate aminotransferase from a microorganism that contains such an enzyme is introduced. Additionally, an acetyl-coA carboxylase may also be introduced. The production of 3-HP can be improved. This can be effected by improved promoters or higher copy number or enzymes that are catalytically more efficient.

Core Innovation

The disclosure describes recombinant C1-fixing bacteria for producing 3-hydroxypropionate (3-HP) from a carbon source. The bacteria comprise nucleic acids encoding a group of exogenous enzymes, including β-alanine pyruvate aminotransferase and malonic semialdehyde reductase, to enable 3-HP production from C1 substrates such as CO and/or CO2.

The engineered bacteria are described as carboxydotrophic acetogens based on Wood–Ljungdahl CO/CO2 fixation, including Clostridium autoethanogenum and related acetogens. The disclosure further states that additional heterologous or overexpressed 3-HP pathway enzymes may be introduced, and that promoter and expression features can be used to improve production in these recombinant strains.

The disclosure also describes anaerobic gas fermentation in bioreactors using industrial waste/off-gas, including CO-containing gases and CO2/H2-containing gas. It further states that 3-HP can be recovered from the fermentation and optionally converted to downstream products, and that combining CO2 fixation pathways increases 3-HP flux while enabling utilization of CO from industrial sources.

The disclosure reports improved 3-HP titers and productivity in combinatorial strains under synthetic gas, including results in C. autoethanogenum combinatorial strains. It indicates that engineered strains with the introduced exogenous enzymes achieve higher 3-HP production in the stated fermentation contexts.

Claims Coverage

The independent claim covers a recombinant C1-fixing bacteria that uses nucleic acids encoding a group of exogenous enzymes, specifically including β-alanine pyruvate aminotransferase and malonic semialdehyde reductase, to produce 3-HP from a carbon source. Dependent claims further refine the bacterial identity, additional exogenous enzymes, nucleic acid expression constraints including codon optimization, cultivation conditions including strictly anaerobic culturing, and downstream conversion of 3-HP into selected materials and chemicals. The inventive features below are those explicitly stated as core refinements within the provided claim set.

Overall, the claim coverage centers on recombinant C1-fixing bacteria carrying nucleic acids that encode exogenous enzymes including β-alanine pyruvate aminotransferase and malonic semialdehyde reductase to produce 3-HP from a carbon source. The dependent claims further narrow the bacterial species, add additional exogenous enzymes operably linked to a promoter, constrain the nucleic acids by codon optimization, require strictly anaerobic culturing, and define downstream conversion of 3-HP into selected materials and chemicals.

Stated Advantages

Documented Applications