Superworms with an appetite for polystyrene could become a useful tool for dealing with the planet’s plastic problem. As reported in the journal Microbial Genomics, scientists from the University of Queensland in Australia have discovered that the common Zophobas morio “superworm” can happily digest polystyrene thanks to a bacterial enzyme in their gut.
In fact, their study found that the superworms that were fed a diet of purely polystyrene actually put on a little bit of weight, suggesting that they may be perfectly happy with surviving on this human-made plastic.
“We didn’t know if the superworms could eat and break down plastic when we started the experiments, but we were hoping they would,” Dr Chris Rinke, lead study author from UQ’s School of Chemistry and Molecular Biosciences, told IFLScience.
“Superworms are technically not worms, but are larvae of the darkling beetle Zophobas morio. Insect larvae have a history of damaging and eating plastic,” Dr Rinke added. “Superworms are larger, hence the name ‘Super’, than many other insect larvae in the same family, so we hoped they would be even better suited to eat plastic – and it turned out they have a great appetite for polystyrene,” he explained.
Previous studies have hinted that Zophobas morio larvae possess this appetite for plastic, but the latest study digs a little bit deeper by looking at the genetics that underpin this talent.
To gain a deeper understanding of their plastic-munching ability, the researchers sequenced the DNA of the microbes living in the superworm gut and managed to identify the bacterial genes that code for the plastic-degrading enzymes. This knowledge, they say, could be used in the near future to screen for other bacteria that encode similar plastic degrading enzymes in their genome.
Utilizing bacterial enzymes is the key to scaling up the vision of greener plastic disposal, Dr Rinke says. As opposed to using tanks filled with hungry superworms to do the job, he believes it will be more efficient to go straight to the plastic-munching enzyme.
“We envision that polystyrene waste will be collected, mechanically shredded, similarly to what the superworms do, and then degraded in bioreactors with an enzyme cocktail. The resulting chemical compounds can then be used by other microbes to synthesize products of higher value, such as bioplastics like PHA,” continued Dr Rinke.
It's unclear if and when this dream will become a reality, but it's certainly good to know we have these creepy crawlies on our side in the war against plastic.