Nano-Nd 2 O 3 reduced soil bacterial community function by altering the relative abundance of rare and sensitive taxa.

Nanoparticulate-Nd 2 O 3 (nano-Nd 2 O 3 ) has been excessively utilized in agriculture, industry, and medicine. Hence, nano-Nd 2 O 3 can have environmental implications. However, the impact of nano-Nd 2 O 3 on alpha diversity, composition, and function of soil bacterial communities has not been thoroughly evaluated. We amended soil to achieve different concentrations of nano-Nd 2 O 3 (0, 10, 50, and 100 mg kg -1 soil) and incubated the mesocosms for 60 days. On days 7 and 60 of the experiment, we measured the effect of nano-Nd 2 O 3 on alpha diversity and composition of soil bacterial community. Further, the effect of nano-Nd 2 O 3 on the function of soil bacterial community was assessed based on changes in the activities of the six potential enzymes that mediate the cycling of nutrients in the soil. Nano-Nd 2 O 3 did not alter the alpha diversity and composition of the soil bacterial community; however, it negatively affected community function in a dose-dependent manner. Specifically, the activities of β-1,4-glucosidase and β-1,4-n-acetylglucosaminidase that mediate soil carbon and nitrogen cycling, respectively, were significantly affected on days 7 and 60 of the exposure. The effect of nano-Nd 2 O 3 on the soil enzymes correlated with changes in relative abundances of the rare and sensitive taxa, viz., Isosphaerales, Isosphaeraceae, Ktedonobacteraceae, and Streptomyces. Overall, we provide information for the safe implementation of technological applications that use nano-Nd 2 O 3 .