Application of Acinetobacter radioresistens to promote the growth of Cucumis sativus L. contaminated with polystyrene microplastics

Currently, although many studies have successfully screened microorganisms with the ability to degrade microplastics (MPs), few studies have focused on their practical application and impacts on the soil-microbe-plant ecosystem. By adding polystyrene-microplastics (PS-MPs) and Acinetobacter radioresistens to the soil, this study aimed to assess their effects on the soil-microbe-plant ecosystem. The findings indicated that PS-MPs enhanced the growth of cucumber (Cucumis sativus L.) and significantly increased the height, stem length, and leaf surface area of cucumber seedlings after inoculation with Acinetobacter radioresistens. The microbial community structure in the rhizosphere soil of cucumber seedlings underwent changes in the high-concentration PS-MPs treatment groups, resulting in a significant increase in both the Shannon index and Simpson index of microorganisms. Compared to the high-concentration PS-MPs treatment, the inoculation treatment increased the soil pH, total potassium content, and iron content, but decreased the total nitrogen content, available phosphorus content, and available potassium content. The transcriptome results showed that cucumber seedlings may respond to environmental changes by regulating photosynthesis, water usage, and phytohormone synthesis. In this study, the growth of cucumber seedlings contaminated with PS-MPs was promoted by the application of Acinetobacter radioresistens. This provides a new perspective for the remediation of PS-MPs contamination in soil.