Wednesday, June 17, 2015

US Patent 9,034,629 to Joule Unlimited titled Recombinant synthesis of medium chain-length alkanes

On about 16 June 2015, Joule Unlimited issued a press release which begins

Joule, the pioneer of liquid fuels from recycled CO2, today announced the issuance of an additional patent on the direct, continuous production of hydrocarbon fuels – extending its ability to target the highest-value molecules of the petroleum distillation process and generate them on demand from sunlight and CO2.

U.S. Patent #9,034,629, issued on May 19, covers both the cyanobacterium and the process for directly converting CO2 into medium-chain alkanes, which are the molecular basis of diesel, jet fuel and gasoline.


The first claim of US 9,034,629

An engineered cyanobacterium,
wherein the engineered cyanobacterium comprises recombinant genes encoding an alkane deformylative monooxygenase having EC number, a thioesterase having EC number, and a carboxylic acid reductase having EC number, wherein the alkane deformylative monooxygenase is encoded by adm, the thioesterase is encoded by fatB or fatB2, and the carboxylic acid reductase is encoded by carB, wherein the thioesterase converts C(.sub.8-12) acyl-ACP to C(.sub.8-12) fatty acid, wherein the carboxylic acid reductase converts C(.sub.8-12) fatty acid to C(.sub.8-12) aldehyde, wherein the alkane deformylative monooxygenase converts C(.sub.8-12) aldehyde to C(.sub.7-11) alkane, and wherein the engineered cyanobacterium produces at least one of heptane, nonane, and undecane in an amount greater than an otherwise identical cyanobacterium, cultured under identical conditions, but lacking recombinant genes encoding alkane deformylative monooxygenase, thioesterase, and carboxylic acid reductase.

Example 4 includes the text:

One or more recombinant genes encoding one or more enzymes having enzyme activities which catalyze the production of medium chain-length alkanes are identified and selected. The enzyme activities include: an alkane deformylative monooxygenase activity, a thioesterase activity, a carboxylic acid reductase activity, and a phosphopanthetheinyl transferase activity, a long-chain fatty acid CoA-ligase activity, and/or a long-chain acyl-CoA reductase activity. Such genes and enzymes can be those described in Tables 1 and 2.

The selected genes are cloned into an expression vector. For example, adm-carB-entD-fatB or adm-acrM-fadD-fatB (or combinations of homologs thereof) are cloned into one or more vectors. See FIG. 6. The genes can be under inducible control (such as the urea-repressible nir07 promoter or the cumate-inducible cum02 promoter). The genes may or may not be expressed operonically; and one or more of the genes can be placed under constitutive control such that when the other gene(s) are induced, the genes under constitutive control are already expressed. For example, one might express adm, carB, and entD constitutively while placing fatty-acid-generating fatB under inducible control; thus when fatty acids are made by fatB after induction, the remainder of the pathway is already present.

One or more vectors are selected and transformed into a microorganism (e.g., cyanobacteria). The cells are grown to a suitable optical density. In some instances cells are grown to a suitable optical density in an uninduced state, and then an induction signal is applied to commence alkane production.

Alkanes are produced by the transformed cells. The alkanes generally have 7, 8, 9, 10, or 11 carbon atoms. In some instances, alkanes are detected. In some instances, alkanes are quantified. In some instances, alkanes are collected.

The claim to priority: This application is related to U.S. Provisional Application No. 61/756,973, filed Jan. 25,2013.

There was a final rejection in the case on 9 October 2014. Among other items, there were rejections over Roessler, including US 8,633,002. Joule Unlimited, in papers and in an interview on 13 January 2015, pointed to the lack of working examples in the cited prior art of Roessler.


Post a Comment

<< Home