UMinho researcher identifies yeasts and bacteria that degrade plastic

A team from the Center for Molecular and Environmental Biology (CBMA) at the School of Sciences at the University of Minho identified a group of yeasts and bacteria capable of degrading plastic. The result is “very promising” and promotes microorganisms as a sustainable alternative in combating global plastic pollution.

In a statement, the Minho academy explains that the study began in 2021 and resulted in particular from the master’s thesis in Applied Biochemistry by João Gomes, which was supervised by Raul Machado and Isabel Soares-Silva, the partnership of the company Vizelpas and European funding through of the scientific projects Ecobib and River2Ocean.

Plastics are widely used around the world because they are resistant and cheap, replacing other materials, but they increasingly accumulate in the environment, with negative effects on ecosystems, the economy and health, says João Gomes, quoted in the statement.

His research applied various yeasts and bacteria to degrade polyethylene, one of the main plastics in everyday life and very polluting, as it has low biodegradability. It was concluded that the Yarrowia lipolytica and the Pseudomonas aeruginos they attached themselves to the surface of the plastic, formed biofilms (first phase of degradation) and produced enzymes that “fed” on the plastic, decomposing it.

Microplastics have been detected in human placenta and breast milk, but also in foods such as water, salt, shellfish, packaged products and bottled drinks, among others. Its biodegradation “can involve microorganisms equipped with enzymes that break the bonds of plastic polymers and transform them into carbon dioxide, water and microbial biomass”, says João Gomes.

The CBMA team now wants to delve deeper into the biological mechanisms involved in the degradation of plastic and find other microorganisms that accelerate this degradation process.

Plastic is widespread in modern society, with applications such as the automotive industry, electronics, construction, agriculture, packaging, medicine and sport, for example. Its exponential production and use generates millions of tons of waste, which is treated mainly by landfill, incineration and recycling, but at enormous costs, thus requiring new technologies for its treatment and disposal.