Systematical review of interactions between microplastics and microorganisms in the soil environment

Terrestrial ecosystems are widely contaminated by microplastics due to extensive usage and poor handling of plastic materials, but the subsequent fate and remediate strategy of these pollutants are far from fully understood. In soil environments, microplastics pose a potential threat to the survival, growth, and reproduction of soil microbiota that in turn threaten the biodiversity, function, and services of terrestrial ecosystems. Meanwhile, microorganisms are sensitive to microplastics due to the adaptability to changes in substrates and soil properties. Through the metabolic and mineralization processes, microorganisms are also crucial participator to the plastic biodegradation. In this review, we present current knowledges and research results of interactions between microplastics and microorganisms (both fungi and bacteria) in soil environments and mainly discuss the following: (1) effects of microplastics on microbial habitats via changes in soil physical, chemical, and biological properties; (2) effects of microplastics on soil microbial communities and functions; and (3) soil microbial-mediated plastic degradation with the likely mechanisms and potential remediation strategies. We aim to analyze the mechanisms driving these interactions and subsequent ecological effects, propose future directives for the study of microplastic in soils, and provide valuable information on the plastic bioremediation in contaminated soils.