Researchers from the Department of Industrial Microbiology and Biotechnology at the Faculty of Biology and Environmental Protection have been studying two types of microscopic fungi found in soil. Fungi of the genus Trichoderma, promote plant growth, while Fusarium, causes plant disease. Researchers are focusing on studying the impact of these fungi on wheat and how microplastics present in the soil can alter this impact.
Our team, led by Dr hab. Przemysław Bernat, Associate Professor at the University of Lodz, as part of a National Science Centre project, has been investigating how microplastics affect the biodegradation activity of fungi. In previous research, we have shown that fungi of the genus Trichoderma are excellent for degrading pesticides commonly used in agriculture. The question then arose as to whether these fungi would still be so useful if they encountered microplastics. We have also been investigating whether the fungi, when in contact with this contaminant, will still have a positive effect on plant growth – in addition to their biodegradation abilities against pesticides, Trichoderma fungi additionally support the growth of plants such as wheat. The study is expected to show whether these capabilities will also be maintained in the presence of microplastics
– explains Dr Anna Jasińska from the Department of Industrial Microbiology and Biotechnology.
The study also hypothesised that microplastics, in addition to influencing the interactions between fungi and wheat, would also affect plant growth, germination, chlorophyll content and the accumulation of heavy metals.
Microplastics are everywhere
What are microplastics? Particles smaller than 5 mm are most commonly referred to microplastics, but they are often much smaller particles. According to some sources, even 0.1mm. – The problem of microplastics is most often discussed in the context of water, but they are also present in soil, explains Dr Anna Jasińska. – Microplastics evaporate with water and can move with air masses over great distances and then fall with rain. They also enter the soil as a result of the decomposition of larger plastics (e.g. foil used to cover agricultural fields) as well as from sludge from sewage treatment plants that are used to fertilise fields.
Microplastics are commonly used as an additive in paints and varnishes, scrubs, toothpastes, shampoos or shower gels. They are used in agriculture and construction but may also be produced during the operation of larger elements containing plastic. – One of the largest sources of microplastics are particles created during the abrasion of car tires – adds Dr Jasińska.
Studies show that we absorb around 5 g of microplastic into our bodies every week (that's more than a teaspoon!). Scientists suspect that it may be deposited in the veins and arteries, but as yet there are no studies to confirm this hypothesis. What's worse, microplastics bind other dangerous pollutants that they encounter, for example in water, which are also absorbed by our bodies.
– However, we know for sure that microplastics have an effect on living organisms, including microorganisms – emphasises Dr Jasińska. – Most of the research to date in this area has been on bacteria, with a few on microscopic fungi. Our team is the first to study the effects of plastics on Trichoderma fungi.
What does the research implicate?
The research is still ongoing, but the results so far shed new light on the threat posed by microplastics. – The first observations showed that the microplastics help the fungi grow, i.e. their mass is greater than in an environment without this contaminant – explains Dr Anna Jasińska. – However, when we investigated what happens to the fungal cells, we found that microplastics cause oxidative stress in the cells. That is, the fungi grow, but their cells show the adverse effects of contamination, e.g. the permeability of cell membranes increases. Secondly, there is an increase in the production of reactive oxygen species, i.e. oxygen species that can interfere with metabolic processes taking place in the cell. – An optimistic result of the study is that, despite the presence of microplastics, the fungi still degraded the pesticides – the researcher adds.
The impact of microplastics on soil fungi remains largely unexplored and is an important area for future research. The obtained results will significantly expand knowledge about the impact of microplastics on terrestrial microorganisms and their impact on plants. – Every day we do not notice the huge role of fungi in the environment and we often do not realize that the destruction of one element of the food chain may threaten many species – emphasizes Dr Anna Jasińska. – So, we need to know how microplastics affect such an important element of the ecosystem as fungi.
Source: Faculty of Biology and Environmental Protection, Department of Industrial Microbiology and Biotechnology, University of Lodz
Edit: Justyna Kowalewska (3PR), Michał Gruberski
Photographs: Anna Jasińska