08 May 2023: A group of scientists, headed by Lawrence Berkeley National Laboratory and UC Berkeley, has engineered bacteria to create new-to-nature carbon-based materials. This breakthrough could offer a promising pathway to produce eco-friendly biochemicals.

Recently published in the journal Nature, a new breakthrough involves the integration of a novel reaction called "carbene transfer reaction" with natural enzymatic reactions through the use of bacteria. This development has the potential to provide sustainable alternatives to traditional chemical manufacturing processes that rely heavily on fossil fuels, thereby reducing industrial emissions in the future.

In a recent publication by the Berkeley Lab, Jay Keasling, a principal investigator of the study and CEO of the Department of Energy’s Joint BioEnergy Institute (JBEI) said,

“What we showed in this paper is that we can synthesise 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.’’

Carbenes are carbon-based chemicals known for their high reactivity and wide range of applications in various types of reactions. For many years, researchers have been interested in utilising carbene reactions in the production of chemicals and fuels, as well as in drug discovery and synthesis. However, these processes could only be conducted in small quantities using test tubes and were dependent on costly chemical compounds to facilitate the reaction.

According to the latest research, scientists have substituted costly chemical reactions with natural substances created by a modified version of Streptomyces bacteria. As these bacteria utilise sugar to manufacture chemical products through cellular metabolism, this approach permits them to carry out carbene reactions without utilising harmful solvents or gases, as is typically done in chemical synthesis. This biological technique is much more environmentally sustainable compared to current chemical synthesis methods, as stated by the study's lead author, Jing Huang, who is a postdoctoral researcher at Berkeley Lab.

During JBEI experiments, the researchers observed the modified bacteria as it transformed sugars into the carbene precursor and alkene substrate followed by metabolising them. The bacterium also developed a modified P450 enzyme that utilised those chemicals to create cyclopropanes, which are high-energy molecules that have the potential to be used in the sustainable production of new bioactive compounds and advanced biofuels. Keasling stated that the interesting reactions can now be conducted within the bacterial cell, where all the necessary reagents and cofactors are produced, allowing the reaction to be scaled up for mass production.

Huang mentioned that utilising bacteria for the production of chemicals can contribute significantly towards the reduction of carbon emissions. As per the findings of some researchers at Berkeley Lab, nearly half of the greenhouse gas emissions are a result of chemical, iron and steel, & cement production. A recent report by the Intergovernmental Panel on Climate Change highlights the need to reduce greenhouse gas emissions by 50% before 2030 to limit global warming to 1.5 degrees Celsius above pre-industrial levels.

While there are still many challenges to overcome in scaling up microbial biomanufacturing, the potential benefits make it an exciting area of research and innovation. By harnessing the power of these tiny microbes, we may be able to create a more sustainable and healthier future.