Effect of copper and nickel on soil microbial activities, abundance, and diversity using the Illumina NovaSeq Platform

Abstract

The objectives of the study were to determine the effects of nickel and copper on soil enzymatic activity, and microbial populations in an environmentally controlled setting. Soil samples were incubated for 100 days, then enzyme assayed, and metagenomically profiled using Illumina amplicon sequencing. No differences were found in enzyme activity in samples treated with copper and nickel sulfates compared to the water control. Surprisingly, potassium induced a significant increase in glycine aminopeptidase (GA). The abundance of the top five bacterial and fungal genera relative remained mostly consistent across treatment groups, with only minor changes in rank order. Copper decreased significantly the abundance of the top five most predominant genera, the levels of amplicon sequence variants (ASV) and Shannon Diversity Index values for both bacteria and fungi compared to controls. The decrease induced by nickel was not strong enough to achieve statistical significance. Future studies should focus on assessing the effect of different concentrations, of copper, and nickel, on soil microbe populations, in lab, to determine the threshold concentrations at which copper and nickel has an effect.