Plastic pollution is one of the critical environmental issues at present. The aggregation of petroleum-based plastics has detrimental effects on the wildlife, environment and human health.
Ideonella sakaiensis grown on poly(ethylene terephthalate) (PET) accumulates poly(3-hydroxybutyrate) (PHB). Image Credit: Shosuke Yoshida.
A new study by scientists from the Nara Institute of Science and Technology unraveled a bacterium that not just degrades hard-to-recycle petroleum-based plastics but also sustainably synthesizes more eco-friendly biodegradable plastics. The study was published in Scientific Reports.
Petroleum-based plastics, such as poly(ethylene terephthalate) (PET), are widely used in day-to-day products like single-use plastic bottles, food wrappers and textiles. These products are disposed of quickly after use but they tend to remain in the environment for hundreds of years.
The plastic pollution caused by the throw-away culture has now gone beyond manageable levels and overwhelmed Earth’s ability to handle it. The environmental effects have become more evident, with human health and wildlife threatened more.
A decrease in the production of unwanted single-use plastics and enhancing waste management systems will help deal with the pollution crisis, but the dependence on the convenience of plastic products might not reduce in the near future. Thus, scientists have been looking at an alternative technique to “clean up” the more steadfast plastics from the environment. Microbes seem to be a promising way to achieve this.
Certain bacteria harbor the necessary enzymes to degrade PET, the most problematic plastic environmentally. Our research has shown that the bacterium Ideonella sakaiensis converts PET into poly(3-hydroxybutyrate) (PHB), a type of poly(hydroxyalkanoate) (PHA) plastic that is biodegradable.
Shosuke Yoshida, Study Senior Author, Nara Institute of Science and Technology
The discovery is specifically prospective as it offers a solution to two existing problems for the sustainability of plastics: degradation of the most persistent form of petroleum-based plastic and sustainable production of biodegradable plastics.
We believe that this discovery could be significant in tackling plastic pollution. as we show that the PET-degradation and PHB-synthesis pathways are functionally linked in I. sakaiensis. This might provide a novel pathway where a single bacterial species breaks down difficult-to-recycle PET plastics and uses the products to make biodegradable PHA plastics.
Shosuke Yoshida, Study Senior Author, Nara Institute of Science and Technology
With the enormous challenge of confronting global plastic pollution, this innovative bacterial approach could be a crucial part of the solution.
Journal Reference:
Fujiwara, R., et al. (2021) Direct fermentative conversion of poly(ethylene terephthalate) into poly(hydroxyalkanoate) by Ideonella sakaiensis. Scientific Reports. doi.org/10.1038/s41598-021-99528-x.