The nano-bio hybrid organisms are a “promising first step toward low-cost carbon sequestration” and eco-friendly plastics manufacturing, according to the University of Colorado.
Using light-activated quantum dots to activate special enzymes within microbial cells, the scientists have created “living factories” which eat harmful CO2.
This is then transformed into useful products such as biodegradable plastic, gasoline, ammonia and bio-diesel, the researchers claim.
“The innovation is a testament to the power of biochemical processes,” said Dr Prashant Nagpal, the lead author of the research, which is published in the American Chemical Society journal.
“We’re looking at a technique that could improve CO2 capture to combat climate change and one day even potentially replace carbon-intensive manufacturing for plastics and fuels,” Dr Nagpal added.
With his team Dr Nagpal, who is an assistant professor in CU Boulder’s Department of Chemical and Biological Engineering, began exploring the potential of nanoscopic quantum dots in 2013.
The dots are tiny semiconductors which can be passively injected into individual cells.
They are designed to attach themselves to specific enzymes and then activate those enzymes on command using specific wavelengths of light.
Dr Nagpal wanted to see if quantum dots could effectively act like a switch to fire up enzymes within microbial cells that can convert airborne CO2 and nitrogen, but don’t naturally do so due to a lack of photosynthesis.
The team diffused these quantum dots into the cells of common microbial species and now – exposed to even small amounts of sunlight – the microbes begin to eat CO2.
“Each cell is making millions of these chemicals and we showed they could exceed their natural yield by close to 200 percent,” Dr Nagpal said.
The microbes, which live in water, release the plastic product to the surface, where it can be skimmed off and harvested for manufacturing.
According to the university, different combinations of dots and light produce different products.
Green wavelengths can cause the bacteria to consume nitrogen and produce ammonia while redder wavelengths make the microbes consume CO2 to produce plastic instead.
In an ideal futuristic scenario, homes and businesses would all be able to send their CO2 emissions directly to a holding pond nearby where microbes would convert them to bio-plastic.
“Even if the margins are low and it can’t compete with petrochemicals on a pure cost basis, there is still societal benefit to doing this,” Dr Nagpal said.
“If we could convert even a small fraction of local ditch ponds, it would have a sizeable impact on the carbon output of towns.
“It wouldn’t be asking much for people to implement. Many already make beer at home, for example, and this is no more complicated.”
:: Sky’s Ocean Rescue campaign encourages people to reduce their single-use plastics. You can find out more about the campaign and how to get involved at www.skyoceanrescue.com