Tiny microbes to offer benefits in decarbonization

June 17, 2023 | Microbiology Lab

A new breakthrough achieved by researchers from the Lawrence Berkeley National Laboratory (Berkeley Lab) and University of California (UC) Berkeley introduces sustainable alternatives to chemical manufacturing from fossil fuels via an engineered bacteria that can be a sustainable source of carbon-based products.

In a process described in the study as “carbon transfer reaction” in which the engineered bacteria combines natural enzymatic reaction to the new-to-nature reaction, to produce carbenes. Carbenes are known to be a highly reactive carbon-based chemical that can be used in various types of reactions.

Researchers created an engineered strain of the bacteria Streptomyces to produce chemical products which the bacteria is capable of doing so via cellular metabolism.

Jay Keasling, principal investigator of the student and CEO of Department of Energy’s Joint BioEnergy Institute (JBEI) shared:, ““What we showed in this paper is that we can synthesize everything in this reaction – from natural enzymes to carbenes – inside the bacterial cell. All you need to add is sugar and the cells do the rest.”

During the experimentation of the students, the engineered bacterium was found to convert sugars into carbene precursor and alkene substrate. The bacterium also showed production of P450 enzyme which uses the carbene and alken to produce cyclopropanes, a high-energy molecule that can be used in sustainable production of novel bioactive compounds and advanced biofuels.

Jing Huang, a Berkeley Lab postdoctoral researcher in the Keasling Lab and one of the first authors of the study, said: “This work enables us to perform the carbene chemistry without toxic solvents or toxic gases typically used in chemical synthesis. This biological process is much more environmentally friendly than the way chemicals are synthesized today.”

The new findings is seen potential to effectively reduce carbon emissions in the future. It was noted by Berkely Lab researchers that close to 50% of greenhouse gases emissions comes from production of chemicals, iron, steel, and cement. Intergovernmental Panel on Climate Change said that in order to aid in the climate crisis and limit global warming to 1.5 degrees Celsius above pre-industrial levels, greenhouse gas emissions should be significantly reduced in half by 2030.

Currently, the envisioned system for green biomanufacturing through the discovered ability of the engineered bacteria will still need further investigation as researchers noted that the the findings is not yet ready for commercialization.

“For every new advance, someone needs to take the first step. And in science, it can take years before you succeed. But you have to keep trying – we can’t afford to give up. I hope our work will inspire others to continue searching for greener, sustainable biomanufacturing solutions,” Huang said.