MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
Key Laboratory of Original Agro-Environmental Pollution Prevention and Control, Ministry of Agriculture and Rural Affairs (MARA), Agro-Environmental Protection Institute, MARA, Tianjin 300191, China.
J Agric Food Chem. 2024 Jul 31;72(30):16674-16686. doi: 10.1021/acs.jafc.4c04206. Epub 2024 Jul 18.
The potential impacts of biodegradable and nonbiodegradable microplastics (MPs) on rhizosphere microbial nitrogen (N) transformation processes remain ambiguous. Here, we systematically investigated how biodegradable (polybutylene succinate, PBS) MPs and nonbiodegradable (polyethylene, PE) MPs affect microbial N processes by determining rhizosphere soil indicators of typical max (soybean)-soil (i.e., red and brown soils) systems. Our results show that MPs altered soil pH and dissolved organic carbon in MP/soil type-dependent manners. Notably, soybean growth displayed greater sensitivity to 1% (w/w) PBS MP exposure in red soil than that in brown soil since 1% PBS acidified the red soil and impeded nutrient uptake by plants. In the rhizosphere, 1% PBS negatively impacted microbial community composition and diversity, weakened microbial N processes (mainly denitrification and ammonification), and disrupted rhizosphere metabolism. Overall, it is suggested that biodegradable MPs, compared to nonbiodegradable MPs, can more significantly influence the ecological function of the plant-soil system.
可生物降解和不可生物降解微塑料 (MPs) 对根际微生物氮 (N) 转化过程的潜在影响仍不清楚。在这里，我们通过测定典型 max（大豆）-土壤（即红土和棕壤）系统的根际土壤指标，系统地研究了可生物降解（聚丁二酸丁二醇酯，PBS） MPs 和不可生物降解（聚乙烯，PE） MPs 如何影响微生物 N 过程。我们的结果表明， MPs 以 MP/土壤类型依赖的方式改变了土壤 pH 值和溶解有机碳。值得注意的是，由于 1% PBS 酸化了红土并阻碍了植物对养分的吸收，因此在红土中，大豆生长对 1%（w/w） PBS MP 暴露的敏感性大于在棕土中。在根际中，1% PBS 对微生物群落组成和多样性产生负面影响，削弱了微生物 N 过程（主要是反硝化和氨化），并破坏了根际代谢。总体而言，与不可生物降解的 MPs 相比，可生物降解的 MPs 可以更显著地影响植物-土壤系统的生态功能。
