The Macquarie University team exposed two different strains of Prochlorococcus to chemicals that they had extracted from plastic grocery bags and PVC matting. They found that this exposure significantly reduced the growth and function of the bacteria compared with the control bacteria.
The researchers observed alterations in the expression of the bacteria's genes, meaning that the genes were not activating in the usual way to produce the required proteins.
Most importantly, the researchers found that the bacteria that they exposed to the plastic chemicals produced lower levels of oxygen than the control bacteria.
Lead author Sasha Tetu explains the wider implications of her team's findings, saying, "Our data shows that plastic pollution may have widespread ecosystem impacts beyond the known effects on macroorganisms, such as seabirds and turtles."
"If we truly want to understand the full impact of plastic pollution in the marine environment and find ways to mitigate it, we need to consider its impact on key microbial groups, including photosynthetic microbes."