Team:Lethbridge/projectobjectives

Project

Objectives

The main objective of this project is to develop the CAB (CO2, acetic acid, and biosurfactant) extraction method to minimize the carbon footprint of extracting unconventional oil reserves by coupling carbon capture with MEOR. CAB extraction includes an engineered bacterial system that (1) captures CO2 and converts it into sugars to fuel (2) acetic acid and (3) biosurfactant production for use in enhanced carbonate oil extraction (Fig. 1). In addition, (4) an inducible “kill switch” gene will be integrated into the bacterial genome to prevent environmental contamination. Our engineered cells will be suitable for use in large-scale bioreactors.

(1) Our aim is to use natural carbon fixation systems to capture CO2 and generate sugar for MEOR bacteria. S. elongatus will be engineered to produce and secrete glucose at levels high enough to sustain E. coli growth. In addition, the H. neapolitanus carboxysome microcompartment will be characterized for use in E. coli using standard assays and monitored for carbon capture efficiency.

(2) Our aim is to use metabolites produced by carbon fixation to fuel acetic acid production by natural E. coli enzymes. To optimize the system for high productivity we will co-localize these enzymes on a scaffold system with a transporter protein from A. acetii to facilitate efficient acetic acid production and secretion for application in oil extraction.

(3) Our aim is to utilize P. aeruginosa enzymes to produce the natural biosurfactant rhamnolipid in E. coli. Rhamnolipid production will be measured by established assays and tested for its efficiency to act as a biosurfactant as part of the CAB extraction method.

(4) Our aim is to produce an environmentally safe method for MEOR by eliminating the risk of environmental contamination with genetically modified DNA. This will be achieved by genome incorporation of an endonuclease that will degrade bacterial genomic DNA if the cells are exposed to an uncontrolled environment.

Figure 1. Schematic of the proposed CAB extraction method. (A) Atmospheric and recycled CO2 are captured by S. elongatus and converted into energy sources used to fuel production of (B) E. coli–produced CAB products (acetic acid and biosurfactant) that are applied to (C) carbonate oil reserves to break down the carbonate rock, produce CO2 to build up pressure, and increase extraction yields.