POLLUTANT EFFECTS ON THE MICROBIAL ECOSYSTEM

Genetic diversity of a microbial community will inevitably be affected by environmental stress. However, our understanding of the implicatio ns of these effects is limited. Genetic exchange between natural micro bial communities appears to be a common phenomenon, mediated by a numb er of microbial processes (conjugation, transformation, and transducti on). These mechanisms of change are presumably adaptations to natural environmental perturbation, e.g., the low levels of antibiotics produc ed by other organisms. However, anthropogenic influences on the enviro nment may be accelerating genetic change within microbiologic ecosyste ms, beyond these natural adaptation rates. This article highlights som e of the perceived risks to ecosystem health and research questions th at need to be addressed.