Recombinant microorganism and methods of production thereof

Abstract

A novel genetically modified microorganisms capable of using CO to produce 1-butanol and / or a precursor thereof, novel methyltransferases and nucleic acids encoding same, methods for producing genetically modified microorganisms using said novel methyltransferases, and methods of producing 1-butanol and / or a precursor thereof by microbial fermentation.

Description

FIELD OF DISCLOSURE[0001]The present disclosure relates to methods for the production of biofuels by microbial fermentation and genetically modified micro-organisms suitable for use in such methods.BACKGROUND[0002]Butanol is an important bulk chemical with a wide range of industrial uses that has worldwide production of 4.5-5.5 million tonnes per annum. It is used as a precursor for the production of acrylate and methacrylate esters (used in coatings, plastics, textiles, adhesives, etc), glycol ethers (coatings, electronics) and butyl acetate (paints, ink, coatings, synthetic fruit flavoring) as well as butylamines (production of pesticides and pharmaceuticals) and amine resins. It also has direct use as a solvent (in ink, dyes, etc), an extractant (for the production of drugs and natural substances such as alkaloids, antibiotics, hormones, and vitamins), and in deicing fluids, cosmetics and chromatography.[0003]Butanol also has potential as a second generation biofuel, and in this ...

AI Technical Summary

Benefits of technology

[0103]While it is not necessary for the substrate to contain any hydrogen, the presence of H2 should not be detrimental to product formation in accordance with methods of the invention. In particular embodiments, the presence of hydrogen results in an improved overall efficiency of alcohol production. For example, in particular embodiments, the substrate may comprise an approx 2:1, or 1:1, or 1:2 ratio of H2:CO. In one embodiment the substrate comprises about 30% or less H2 by volume, 20% or less H2 by volume, about 15% or less H2 by volume or about 10% or less H2 by volume. In other embodiments, the substrate stream comprises low concentrations of H2, for example, less than 5%, or less than 4%, or less than 3%, or less than 2%, or less than 1%, or is substantially hydrogen free. The substrate may also contain some CO2 for example, such as about 1% to about 80% CO2 by volume, or 1% to about 30% CO2 by volume.

Problems solved by technology

However, these crops are required for food and many crops also require high agricultural inputs in the form of fertilizers.

These limitations mean that first generation biofuels are considered unsustainable and the greenhouse gas reductions that can be achieved are limited.

However the synthesis process requires use of non-renewable resources as well as suffering from being expensive and non-specific in the products formed.

This method has the unwanted by-product of acetone which is usually produced at about half the volume of butanol which therefore substantially reduces the yield.

Additionally, this method of fermentation is limited by the toxicity of butanol to the micro-organism which results in growth being almost completely inhibited at such low butanol concentrations as 1.5% (Köpke and Dürre 2010).

This results in the undesirable use of arable land to produce fuel rather than food.

It can also exacerbate problems related to deforestation and desertification.

These issues present significant difficulties in effectively transforming Clostridia species.

Most Clostridia have one or more restriction / methylation systems to protect against foreign and phage DNA which means that transformation is particularly difficult and unpredictable.

Images