The Effect of Metal Oxide Nanoparticles on Functional Bacteria and Metabolic Profiles in Agricultural Soil

A significant knowledge gap in nanotechnology is the absence of standardized protocols for examining the effect of engineered nanoparticles on soil microorganisms. In this study, agricultural soil was exposed to ZnO, SiO2, TiO2 and CeO2 nanoparticles at 1 mg g(-1). The toxicity effect was evaluated by thermal metabolism, the abundance of functional bacteria and enzymatic activity. ZnO and CeO2 nanoparticles were observed to hinder thermogenic metabolism, reduce numbers of soil Azotobacter, P-solubilizing and K-solubilizing bacteria and inhibit enzymatic activities. TiO2 nanoparticles reduced the abundance of functional bacteria and enzymatic activity. SiO2 nanoparticles slightly boosted the soil microbial activity. Pearson's correlation analysis showed that thermodynamic parameters had a strong correlation with abundance of functional bacteria and enzymatic activity. These findings demonstrated that the combined approach of monitoring thermal metabolism, functional bacteria and enzymatic activity is feasible for testing the ecotoxicity of nanoparticles on agricultural soil.

纳米技术中一个重大的知识缺口是缺乏用于检测工程纳米粒子对土壤微生物影响的标准化方案。在这项研究中，农业土壤暴露于浓度为1毫克/克的氧化锌、二氧化硅、二氧化钛和二氧化铈纳米粒子中。通过热代谢、功能细菌的丰度以及酶活性来评估其毒性效应。观察到氧化锌和二氧化铈纳米粒子阻碍产热代谢，减少土壤中固氮菌、解磷菌和解钾菌的数量，并抑制酶活性。二氧化钛纳米粒子降低了功能细菌的丰度和酶活性。二氧化硅纳米粒子略微促进了土壤微生物活性。皮尔逊相关性分析表明，热力学参数与功能细菌的丰度和酶活性有很强的相关性。这些研究结果表明，监测热代谢、功能细菌和酶活性的综合方法对于检测纳米粒子对农业土壤的生态毒性是可行的。