Autor:innen:
Rajiv Kumar Mandal | Rhine-Waal University of Applied Sciences | Germany
Nayan Jyoti Gogoi | Rhine-Waal University of Applied Sciences | Germany
Patrik Leka | Rhine-Waal University of Applied Sciences | Germany
Dr. Nadine Merettig | Rhine-Waal University of Applied Sciences | Germany
Florian Wichern | Rhine-Waal University of Applied Sciences | Germany
Agricultural soils are considered an important sink of microplastics (MPs), which can bind with other pollutants, such as heavy metals. Further, the MPs particles form a habitat for soil microbial communities. The interplay between MPs, heavy metals and other pollutants with soil bacteria can facilitate the development and transfer of antibiotic resistance genes (ARGs). Organically managed soils, as compared to conventional soils, are expected to be less affected by organic and inorganic pollutants derived from plant protectants. Therefore, this study aimed to evaluate the influence of farm management on the prevalence of ARGs on MPs. To this end, MPs and heavy metals were extracted from soil samples, and the ARGs present on the MPs surfaces and in the bulk soil samples were isolated. Six pairs of samples from organic and conventional arable soils were collected at the lower Rhine, North Rhine-Westphalia (Germany). MPs were extracted from the soil samples using a wet sieving method, and polymer types were determined through Raman spectroscopy. Furthermore, heavy metals were quantified in the bulk soil, and microbial DNA was extracted from the soil and the MPs’ surfaces. A qPCR was used to identify and quantify bacterial, fungal, and archaeal genes. In addition, intI genes were quantified to determine the presence of ARGs. There was no significant difference in the abundance of MPs in organic and conventional soil samples, which were dominated by polyethylene. The concentration of heavy metals was also similar in soil samples of organic and conventional farms. Organically managed soils revealed a slightly higher microbial abundance as compared to conventionally managed soils. However, the presence of intI was detected in some soil samples only, but in soils from both management systems. Hence, it was concluded that farm management (organic and conventional) does neither influence MPs presence nor ARG development in the investigated systems. In addition to the above, results from ongoing research on the effects of MPs-heavy metal interactions on ARGs development in soil microbial communities will be presented.