Biodegradable microplastics impact on soil: how poly-3-hydroxybutyrate alters microbial diversity and nitrogen mineralization processes

Abstract Background Poly-3-hydroxybutyrate (P3HB) is a biodegradable plastic that may affect soil quality and plant growth. To explain the observed deterioration of plant growth, this study investigated the effects of P3HB microplastics on the soil microbiome and its activity related to content of nutrients and their transformation processes. A pot experiment was conducted using soil contaminated with five different doses of P3HB, both with and without maize. Soil mineral nitrogen forms, microbial properties as well as plant biomass were determined. Results P3HB significantly altered soil properties by stimulating microbial respiration, enhancing carbon turnover, and shifting nitrogen forms, notably reducing NO₃⁻ availability. The fungal community was more sensitive to P3HB compared to the bacterial one. Fungal genera such as Tetracladium, Exophiala, and Pseudogymnoascus were stimulated; others such as Gibberella and Gibellulopsis declined. In the bacterial community, P3HB promoted the growth of copiotrophic P3HB degraders (e.g., Actinobacteria, Alphaproteobacteria); increased the abundance of anaerobes (Clostridia); decreased nitrifying groups (Nitrososphaeria, Nitrospiria); and reduced oligotrophic taxa (Vicinamibacteria, Thermoleophilia). These changes led to altered nutrient cycling, including inhibited nitrification and reduced mineral nitrogen availability, contributing to decreased maize growth. Conclusions Soil contamination with ≥ 1% P3HB microplastics disrupts microbial structure and nutrient dynamics, with potential negative effects on soil fertility and plant productivity. Graphical abstract

Abstract licence: CC BY-NC-ND

1. 17.

   phyloseq: An R Package for Reproducible Interactive Analysis and Graphics of Microbiome Census Data · 2013

77 more references, whose wording the paper’s licence keeps private.

A person counts once a day per paper. We keep no cookie and no address: a reader is a hash that changes every day. Any month under five reads shows no number.