Toxicity of Nickel to Microbes: Environmental Aspects

This chapter reviews the literature on the overt and covert toxicities of Nickel to microorganisms and to their activities in natural environments, focusing on the microbial aspects that have not been recognized by regulatory agencies responsible for protecting the biosphere from harmful exposures to toxicants.

Abstract

This chapter reviews the literature on the overt and covert toxicities of Nickel (Ni) to microorganisms and to their activities in natural environments. Attention is directed to the mediating influence of abiotic environmental factors and, to a lesser extent, of biotic factors that modify the toxicity of Ni to the microbiota. In the studies, it is found that Ni reduces or completely inhibits growth of microbes in synthetic media and, to a lesser extent, in samples from natural environments (i,e., soils and fresh, estuarine, and marine waters). These overt deleterious responses to Ni are manifestations of more covert effects, such as the effects of Ni on cell surfaces, on DNA replication, transcription, and translation, and on other metabolic activities, including photosynthesis, nitrogen fixation, respiration, and fermentation. The establishment of criteria for permissible levels of Ni in the environment is also discussed, focusing on the microbial aspects that have not been recognized by regulatory agencies responsible for protecting the biosphere from harmful exposures to toxicants.