Studies on heavy metals and their environmental impact are always in the limelight of basic research. Although the requirement of heavy metal is at tracer level for various biochemical activities of all living organisms, generation of wastes with various oxidation levels of heavy metals poses severe hazard and toxicity on human biology.
Some of the bacterial species exhibit high tolerance and resistance towards high concentration of heavy metals. The reason behind such resistance and tolerance behavior of microorganisms needs more elucidation because of the emergence of resistance species .Microorganisms of marine origin in general, thrive under extreme environmental conditions, which provide them enormous potential and tolerance.
Actually, most of the toxic compounds especially heavy metals, preferably follow the reduction pathway instead of oxidative pathway by native microbes, with a few exceptions, since the reduced forms are less toxic. Scientists reported that bacteria follow efflux system; accumulation; complexation and reduction mechanisms to tolerate heavy metal. Among heavy metals, environmental impact of chromium is at higher level, and the environmental behavior of chromium lies in its oxidation states. The higher oxidation state is more toxic (10-100 times) than lower oxidation state. According to the available reports, only 0.1 ppm of Cr (VI) is recommended for fresh water and marine life and 0.8 ppm for irrigation water, whereas for Cr (III), the level raised to 0.5-5.0 ppm regardless to fresh, marine, irrigation and drinking water.
Share your views at: https://www.omicsonline.org/ArchiveBLM/specialissueBLM-S1.php