Rhodospirillum rubrum metabolic state during conversion of CO2 to ethylene
EMSL Project ID
60175
Abstract
Ethylene (C2H4) is an essential plant hormone and is the chemical building block for nearly all plastics, detergents, and coolants. More ethylene is synthesized than any other industrial compound (~30 million tons annually in the U.S.) and is currently sourced primarily from fossil fuels by energy intensive processes. Recently we discovered a complete anaerobic pathway in soil and freshwater bacteria for the conversion of renewable CO2 and lignocellulose to ethylene [North et al., 2020, Science]. This both provides the first explanation for the presence of ethylene in anaerobic soils and provides a microbial platform for engineering industrially impactful levels of bioethylene. In order to understand metabolic ethylene capacity in soil and freshwater bacteria and engineer organisms for optimized ethylene synthesis, we are employing predictive thermo-kinetic computational modeling and genetic/metabolic engineering (DE-SC0022091 to J.A.N., K.C.W., W.R.C.). Accurate predictive models that inform engineering targets require detailed knowledge of the metabolic state and carbon flux of organisms during conversion of CO2 to ethylene. This project will leverage EMSL’s extensive untargeted metabolomics capabilities (Aim 1) through 1H-NMR, lipidomics, and CHNOS element analysis. Metabolite identities and relative concentrations, in conjunction with cellular CHNOS element ratios will be used to refine genome-scale predictive computational models, providing deep insights into engineering targets for enhanced ethylene synthesis. Subsequently, EMSL 13C stable-isotope NMR capabilities (Aim 2) followed by metabolic flux analysis will provide an initial picture of CO2 flux to ethylene versus competing pathways in our native and engineered Rhodospirillum rubrum strain. This will provide critical information on ethylene synthesis capacity in a model soil and freshwater and serve as a tool to validate our thermo-kinetic models.
Project Details
Project type
Exploratory Research
Start Date
2021-12-01
End Date
2022-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Co-Investigator(s)