By Alejandra Martins
The students, from the department of Molecular Biology and Biochemistry at Yale University, in the United States, carry out field work in the Amazon rainforest as part of their course, where they collect endophyte organisms: fungi or bacteria that live at least part of their life in symbiosis in plant tissues without causing disease.
Pria Anand, one of the students, decided to investigate whether the endophytes she had collected in Ecuador in 2008 registered biological activity in the presence of plastic.
After Anand's graduation, other students continued the search. Jeffrey Huang investigated the ability of organisms to break chemical bonds.
Jonathan Russell, for his part, identified the most efficient enzymes in the decomposition of polyurethane, a plastic widely used in the production of synthetic fibers, parts for electronic devices and foams for thermal insulation.
"Each student collected plant samples around a specific topic, for example, plants with medicinal uses such as antibiotics etc. We chose plants identified with the help of the botanist Percy Nuñez, also the author of the study, who is an expert in the coastal and Amazon regions from Ecuador, "Russell told BBC Mundo.
Russell observed one day that some of the plastic in one of the so-called Petri dishes (used for cultures in the laboratory) had disappeared.
What the students had discovered is that the fungus called Pestalotiopsis microspora can degrade plastic. Several species of fungi can decompose plastic at least partially, but Pestalotiopsis it is the only one that can do it without the presence of oxygen, which is essential for future landfill applications.
"This discovery shows that wonderful things can happen when we encourage creativity in students," said Kaury Lucera, a professor in the department of Molecular Biology at Yale University.
The use of tons of plastic and the difficulties in recycling it are a great challenge for science.
Plastic bags are used many times for only a few minutes - the time it takes to get home from the supermarket - but they can take hundreds of years to decompose. Many end up in the sea, where they are fatally ingested by seabirds.
But transforming a lab finding into an industrial-scale tool can be a long process. Russell cautions that the Yale students' discovery is not a magic bullet, but a modest step toward an important goal.
A new group of students is looking at whether endophytes collected on recent trips to the Amazon can be used to break down even harder-to-break plastics like polystyrene.
"I hope this project inspires other students to invent their own mechanisms or use the ones we developed to find organisms that degrade polymers. It doesn't take many resources or equipment to design a simple and powerful experiment in science," Russell told BBC Mundo .
"Anyone can be a scientist if he focuses his mind for that purpose!"
The results of the research were published in the journal Applied and Environmental Microbiology. The jungle expeditions were funded by the Howard Hughes Medical Institute.