Hydrolyzable microplastics in soil—low biodegradation but formation of a specific microbial habitat?

Abstract Microplastics (MP, plastic particles between 0.1 and 5000 ?m) contaminate agricultural soils through the application of organic fertilizers, sewage sludge, mulch. MP surfaces MP-soil interface provide specific habitats for soil microorganisms—the plastisphere. Microorganisms in plastisphere may benefit from utilizing as a carbon (C) source. Hydrolyzable with ester bonds are susceptible to enzymatic depolymerization by hydrolysis. In microcosm experiment, we investigated biodegradation small large (< 0.5 mm 0.5–2 respectively), hydrolyzable (a poly(lactic acid)/poly(butylene co-adipate terephthalate) blend, PLA/PBAT) non-hydrolyzable (low-density polyethylene, LDPE) polymers, effects these on microorganisms dry wet MP-amended soil. affected neither abundance composition main microbial groups (fungi, Gram-negative, Gram-positive bacteria), activities ß-glucosidase, ß-xylosidase, lipase, phenoloxidase, nor respiration Only PLA/PBAT were significantly mineralized (15.4% initial PLA/PBAT-C after 230 days). mineralization coincided enhanced lipase ß-glucosidase individual extracted incubation (compared LDPE non-incubated particles). We detected cracks using scanning electron microscopy, indicating initiation biodegradation, presumably due lipases. Results suggest that is polymer-specific habitat lipase-producing microorganisms. Our study demonstrates analyzing biogeochemical interactions within plastispheres essential assess fate their impacts microbially driven processes.