Heavy Metal Resistance of Bacteria as Biological Indicator for Environmental Pollution

Abstract

Biological methods in controlling long- and short-term environmental pollution become world-wide more and more of interest. Various materials like lichens, fungi, grass and diverse animals have been proposed for use as bioindicators (1). Currently, the application of microbial organisms for bioindication and environmental management is discussed. Responses of natural microbial communities to toxic pollutants, for example the bacterial resistance to heavy metals, are of important ecological significance. Such organisms may serve as systems for indicating and controlling environmental pollution. Heavy metal resistance in bacteria is mostly encoded by genes located on plasmids (3). It is also well known that heavy metal resistance is associated with single or multiple antibiotic resistance. However, very few studies of the frequency of plasmids encoding resistance to heavy metals in natural environments have been reported.