According to a new study, microbes in the oceans and on land are emerging to break down plastic worldwide.
In a study published in the journal Microbial Ecology, researchers from the Chalmers University of Technology in Sweden revealed 30,000 distinct enzymes capable of digesting ten different types of plastic. It’s the first time a large-scale study of bacteria’s ability to decompose plastic has been conducted.
According to the study, microbes evolved in reaction to plastic pollution. In the preceding 70 years, mass production of plastic has increased. Plastic production has risen considerably in recent decades, from 2 million tonnes in 1950 to 368 million tonnes in 2019.
“We found multiple lines of evidence supporting the fact that the global microbiome’s plastic-degrading potential correlates strongly with measurements of environmental plastic pollution – a significant demonstration of how the environment is responding to the pressures we are placing on it,” Aleksej Zelezniak, one of the study’s researchers, said in a statement.
Approximately 12,000 enzymes were discovered in ocean water samples collected from 67 places at three separate depths. According to the study, higher quantities of degrading enzymes were regularly identified at deeper depths due to increased plastic pollution. In addition, 18,000 plastic-degrading enzymes were discovered in soil samples collected from 169 locations in 38 nations and 11 ecosystems. Scientists found that the enzyme count was higher in soil samples compared to ocean ones.
According to the study, about 60% of the enzymes discovered did not fit into any known enzyme classifications, necessitating more investigation.
“The next step would be to test the most promising enzyme candidates in the lab to closely investigate their properties and the rate of plastic degradation they can achieve,” Zelezniak said.
“From there, you could engineer microbial communities with targeted degrading functions for specific polymer types.”
This might suggest using the new enzymes to speed up the biodegradation of industrial plastic waste, hence reducing the need for new plastics.
In 2018, scientists accidentally produced the first plastic-degrading enzyme after identifying a plastic-eating bug in Japan in 2016. In 2020, scientists improved that enzyme, allowing it to degrade plastic six times faster. In the same year, German scientists developed an enzyme capable of decomposing a ton of plastic bottles in ten hours.