关键词: 微塑料, 生物炭, 普通白菜, 细菌, 群落结构, 功能预测

Abstract: Pot experiments were conducted using‘Sijixiaobaicai’to study the effects of biochar application on the growth of pakchoi on soils contaminated by different microplastics（PP，PE，and PVC）and on soil bacterial community structure and abundance．Functional prediction of soil bacterial community was also conducted．The results showed that microplastic contamination inhibited the fresh mass and leaf number of pakchoi．Biochar application increased the fresh mass，plant height，and root length of pakchoi grown on microplastic-contaminated soils．Co-treatment with microplastics and biochar significantly increased soil bacterial abundance．The highest soil bacterial abundance was found in PER treatment．Co-treatment with PE or PVC and biochar significantly increased the Chao1 index and ACE index of soil bacteria．On the phylum level，Actinobacteria，Proteobacteria，Chlorobacteria，Firmicutes，and Acidobacteria are dominant taxa．Co-treatment with microplastics and biochar increased the relative abundance of Actinobacteria，but decreased the relative abundances of Proteobacteria and Acidobacteria．Soil pH value and organic carbon，ammonium nitrogen，nitrate nitrogen，and available potassium contents were primary influence factors for changes in soil bacterial community structure．Functional prediction of soil bacterial community using PICRUSt showed that biochar application increased the relative abundances of several metabolic pathways of beneficial bacteria，including soil metabolism，environmental information processing，and organic system．To conclude，biochar application had a significant impact on the bacterial community in microplastic-contaminated soils，though the degree of influence varied with the type of microplastics．

Key words: microplastic, biochar, pakchoi, bacteria, community structure, functional prediction