Metatranscriptomics of microbial biofilm on plastic foil

Microbial communities in soil are a complex and sensitive system which secures soil health, nutrient cycling and the degradation of natural and xenobiotic substances. As plastic pollution is increasing worldwide, our soils are susceptible to the adverse effects of plastic debris in soil. So far very little is known about microbial degradation processes that take place once plastic debris gets incorporated into the soil matrix. In this study, we conducted the first metatranscriptome analysis of polyethylene (PE)-associated biofilm communities in soil by screening for microbial communities in both and forest soil over a 53-day period. Our findings suggest that even forest soils harbour a variety of plastic-associated genes (PETase, alkB etc..) and therefore carry the enzymatic potential for microbial plastic degradation. We found that the plastic-degrading taxa were upregulated in the early stages of biofilm growth and the PE-degrading enzymes alkB1/alkM and transporters such as FadL, livG, livF, livH and livM and fatty acid ß-oxidation pathway were active during the maturation of the biofilm. In the quest for plastic-degrading enzymes, our findings emphasize the importance of considering natural and diverse soil ecosystems, due to their apparent functional potential. With this study, we elucidate the underlying molecular dynamics that take place during biofilm development of a PE-associated plastisphere in soil. Furthermore, in the light of an ever increasing plastic production worldwide, our research tackles the pressing question whether or not natural microbial communities carry the potential to biodegrade petrol-based plastic in the (soil) environment.