A Microbial Consortium Enabling Complete Feedstock Conversion

Default ARPA-E Project Image

Project Term:
08/12/2021 - 08/11/2024

Critical Need:

A robust and sustainable bioeconomy can only be realized through the industrial-scale, carbon-neutral synthesis of fuels, chemicals, and materials. Biofuels, along with a growing number of other sustainable products, are made almost exclusively via fermentation, the age-old technology used to produce foods such as wine, beer, and cheese. Current commercial methods to produce ethanol biofuel from sugar or starches waste more than 30% of the carbon in the feedstock as carbon dioxide (CO2) in the fermentation step alone. This waste limits product yields and squanders valuable feedstock carbon as greenhouse gas CO2. Preventing the loss of carbon as CO2 during bioconversion, or directly incorporating external CO2 as a feedstock into bioconversions, would revolutionize bioprocessing by increasing the product yield per unit of carbon input by more than 50%.

Project Innovation + Advantages:

The aviation industry requires energy-dense, carbon-based fuels, which are difficult to achieve biologically because of low yields and poor carbon conversion efficiency. The University of California, Berkeley, will engineer an approach to reach near 100% carbon conversion efficiency. A single organism can be limited by CO2 loss from core metabolic reactions. Coupling a heterotroph (an organism that cannot produce its own food like an animal) with an autotroph (an organism that produces its own food using light, water and carbon dioxide like a plant) will enable CO2 recycling and complete feedstock conversion. The proposed systems will use a heterotrophic production strain to convert sugar substrates into biofuels via a carbon-conserving synthetic metabolism, co-cultured with a phototrophic strain engineered to be chemotrophic to enable CO2 utilization. In combination, the two strains re-capture and recycle CO2 released during the sugar fermentation. These changes combined will ensure complete carbon conservation into liquid fuel, making biofuels competitive with fossil fuels. Although the proposed work targets aviation fuel, the platform will be designed to swap in various strains to generate different biofuel products.

Potential Impact:

The application of biology to sustainable uses of waste carbon resources for the generation of energy, intermediates, and final products---i.e., supplanting the “bioeconomy”—provides economic, environmental, social, and national security benefits and offers a promising means of carbon management.


If successful, the new technologies are expected to catalyze new conversion platforms for biofuels and other high-volume bioproducts that are capable of promoting U.S. energy security by increasing recoverable product from the same mass of feedstock through the avoidance of wasting carbon in the form of CO2.


This program funds cutting-edge technologies to de-risk the engineering of carbon optimized bioconversion pathways capable of generating valuable bioproducts such as sustainable aviation fuel without emission of CO2 as a waste product.


The technologies funded by this program can increase the potential bioproduct output by more than 40% without requiring another square inch of land or pound of feedstock, while catalyzing the next generation of carbon optimized bio-based manufacturing.


ARPA-E Program Director:
Dr. David Babson
Project Contact:
Dr. Patrick Shih
Press and General Inquiries Email:
Project Contact Email:


Lawrence Berkeley National Laboratory

Related Projects

Release Date: