Scientists have discovered a way of using bacteria to produce graphene – a nanomaterial composed of a single layer of carbon atoms with extraordinary properties. Graphene is strong, flexible and conductive with the potential to revolutionise electronics, but using it has remained difficult. “For real applications, you need large amounts,” says Prof Anne S Meyer, of the University of Rochester, New York. Her team have used a bacterium called Shewenella to produce large quantities of thinner, more stable graphene.
Mopping up oil spills
After the catastrophe of the BP oil spill in 2010, scientists observed many species of bacteria that broke down the oil, including one previously unknown to science. The oil spill was the largest in history, dumping almost 5m barrels of oil into the Gulf of Mexico. The bacteria that feasted on the oil compounds played an instrumental role in reducing the impact of the spill and could be used if any future disasters occur.
Scientists at the University of Edinburgh have developed a low-cost biosensor which uses bacteria to detect unsafe levels of arsenic in drinking water. Arsenic contamination is a health risk to millions of people worldwide, causing cancer and death. The bacteria are genetically engineered to fluoresce in the presence of arsenic, with the biosensor attaching to a smartphone, which displays an easily readable pattern to show the levels of the element.
Cutting plastic waste
In 2016, Japanese scientists identified a species of bacterium that feeds on PET – the plastic used to make disposable drink bottles. The bacteria use two enzymes to break the PET down into two components that can then be used to synthesise new PET, breaking the reliance on fossil fuels and reducing plastic waste. The scientists are currently working on optimising these enzymes to make recycling PET more efficient.
In 2015, MIT scientists used genetically modified bacteria to detect tumours in mice. The researchers fed a harmless strain of GM bacteria to the mice, which produced a luminescent signal when it encountered a tumour. This luminescence could be detected in urine, and allows detection of tumours as small as one square millimetre. Scientists ultimately aim to apply this diagnostic method to humans.