Engineers have developed a strain of a common bacterial species that can feed exclusively on the three major sugars present in corn stalks. While the new multiple-sugar-consuming strain of the bacteria Pseudomonas putida is interesting in its own right, a new paper published in Nature Communications on July 29, 2026 outlines the broader implications of this project for the future of biomanufacturing.
The research team led by bioengineers at the University of California San Diego uncovered new insights for leveraging the process of evolution to create novel strains of microbes that are highly adept at feeding off of low-cost feedstocks like agricultural waste or even mixed plastics.
"Given the likelihood that some of the most economically viable biomanufacturing feedstocks of the future will be complex mixtures of different components, this work has far reaching implications. With our automated culturing platform, we engineered a bacterial strain using evolution capable of taking up all three sugars found in corn stalks quickly and simultaneously," said Adam Feist, a bioengineering professor at UC San Diego and the senior author on the paper. "We found that the key was evolving strains under a specific mixture of sugars that required complete consumption of all three of the sugars in order for the strain to outcompete other variants. This produced versatile generalist strains, rather than narrow specialists."
Looking ahead, these kinds of versatile generalist strains of bacteria could be especially relevant for building tomorrow' biomanufacturing economy that makes efficient use of low-cost feedstocks that are not highly uniform — like agricultural waste and mixed plastics.
Feist is the director of the Future Biomanufacturing Center at UC San Diego . In order to carry out this research, the team used the automated ALEbot (Adaptive Laboratory Evolution robot) platform that Feist and his team developed at UC San Diego. The team used the ALEbot to run multiple experiments in parallel around the clock for months. This allowed them to direct the evolution of these new strains of Pseudomonas putida.
The researchers started with a strain of the Pseudomonas bacteria that had previously been engineered to be capable of consuming the three sugars commonly found in agricultural waste: glucose, xylose and arabinose. But this starting strain had not been sufficiently optimized to meet the efficiency demands for biomanufacturing, which is where the new work fits in.
The engineers went on to program this bacterial strain to produce a desirable molecule, indigoidine, which is a blue pigment used for dyeing clothing.
"We partnered with research teams across three US national laboratories to bring the necessary expertise together. In this arrangement, we each contributed our unique skill sets to both develop useful biomanufacturing strains and lay the groundwork for additional applications," said Feist, a faculty member in the Shu Chien-Gene Lay Department of Bioengineering at the UC San Diego Jacobs School of Engineering.
Paper: " Simultaneous optimization of lignocellulosic sugar catabolism via systematic laboratory evolution under complex selection pressure ," in Nature Communications.
Author information: Author information is listed here .
Funding:
U.S. Department of Energy (DOE)
Funding details are listed here .
Disclosures: The authors declare no competing interests.
Author affiliations
University of California San Diego
Joint BioEnergy Institute
Inha University, South Korea
