Morphological Changes and Oxidative Stress in Actinobacteria During Removal of Heavy Metals

COLIN VERÓNICA LETICIA; VILLEGAS LILIANA BEATRIZ; PEREIRA CLAUDIA ELIZABETH; AMOROSO MARIA JULIA; ABATE CARLOS MAURICIO

Actinobacteria, Application in Bioremediation and Production of Industrial Enzymes

Science Publisher, A Taylor and Francis Group Co

Año: 2013; p. 44 - 55

Heavy metal pollution is one the most serious environmental problems facing our planet today and immediate solutions are needed to tackle it. Heavy metals such as copper (Cu) and chromium (Cr) play an important role as trace elements in biochemical reactions but these metals are toxic at higher concentrations. Cu is a very versatile heavy metal, able to cycle between two redox states, oxidized Cu(II) and reduced Cu(I), with Cu(I) being highly unstable. On the other hand, Cr(VI) which is more mobile and soluble in water than Cr(III), is always toxic to living organisms and has been listed as a priority pollutant and a human carcinogen by the US Environmental Protection Agency. In our region (Tucumán-Argentina), mining and industrial activities have led to large scale Cu and Cr contamination. At present, the conventional technologies used to remove heavy metals from the environment involve physicochemical processes, which are costly and require large amounts of energy and specialized equipment. Microbe-based heavy metals removal is now considered to be an effective alternative method to the conventional processes. In this connection, actinobacteria, a group of free-living saprophytes microorganisms found predominantly in soils, have been identifi ed as potential bioremediators of environment contaminated with heavy metal. The present chapter discusses both morphological alterations and antioxidant enzymes levels changes in native actinobacteria of our region, during oxidative stress caused by Cu(II) and/or Cr(VI).