Nano-toxicity to Microbes: Potential Implications of Nanomaterials on Microbial Activity

Abstract

The increasing concentration of engineered nanomaterials and their accumulation in the environment is the major concern for toxicity to soil microbial community. The engineered nanomaterials have shown positive and negative effect on microbes, microbial physiology, and their enzymatic activities, which play a significant role in various biogeochemical cycles to maintain ecosystem. The disorganization of microbial community structure affects the soil fertility and ecosystem, which involved in disintegration of complex substrates, remediation of pollutants, and plant growth. Various metal nanoparticles and carbon-based nanomaterial have shown their role in induction or suppression of various microbial enzymatic activities like dehydrogenase, phosphates, urease, nitrogen fixation, and ammonia oxidation. Therefore, we reviewed the effect of different types of engineered nanomaterials such as silver, zinc oxide, copper oxide, titanium oxide, iron, and carbon-based nanomaterial on the microbial community structure, which is needed for the harmonization of soil and water ecosystem. Silver, copper, and carbon-based nanomaterial have been studied broadly in terms of toxicity to microbial communities. The toxicity level of various nanomaterials depends on nanomaterial concentration and structure of exposed microbial community. The mechanism of nanomaterial toxicity to microbial enzymatic activities, role of nanomaterials in reactive oxygen species generation, and their impact on microbial reduction have been discussed in the chapter.