7th joint conference "Joint Microbiology & Infection Conference 2024" of the DGHM and VAAM

Abstract: Terrestrial ecosystems are exposed to extensive pollution with microplastics (MP), with agricultural practices and unintentional dispersal especially impacting arable soils. A profound understanding of the interactions of MP with physical, chemical, and microbial factors in agricultural soils is critical to assess impacts on crop production. Our research, as part of the Collaborative Research Center 1357 “Microplastic” at the University of Bayreuth, aims to elaborate a comprehensive insight into the response of prokaryotic and fungal soil microbiota to MP pollution. We employ environmental samples, bench-scale microcosms, and controlled greenhouse experiments to determine MP-induced alterations in the overall taxonomic and functional diversity of soil- and plant-associated microbiota, as well as changes in soil biogeochemical parameters and processes. In soil microcosms, we show that soil microbes tend to be more clearly responsive to biodegradable vs. conventional plastics, but that effects vary with soil type. Next, maize (Zea mays) and strawberries (Fragaria × ananassa) were cultivated in soils amended with different types of conventional (LDPE, PET, PS) or biodegradable (PBAT) MP. The results reveal a distinct influence of plant hosts on prokaryotic soil microbiomes, largely overruling direct impacts of MP in both plant systems. However, variations in alpha diversity were evident, depending on the plant species, root proximity, and also on some, but not all plastic types. Interestingly, the degree of mycorrhization of maize plants was markedly reduced only for one polymer type. Our ongoing work aims to unravel the metabolic potential and functional context of microbial taxa most responsive to plastic amendment. We also discuss a polymer-specific approach towards extracting and characterizing environmental plastisphere microbiota, based on isopycnic density separation. Overall, our research within the CRC “Microplastic” advances the curent understanding of the intricate interplay between soil, soil microbes and microplastics as soil pollutant. This is an important contribution to the development of sustainable management strategies for soils and agroecosystems. 

Studying the impacts of microplastics on microbes in agricultural soil

Aileen Jakobs

Speaker