Heavy Metals Accumulation Potency of Aspergillus Niger and Aspergillus Flavus Indigenous to Paper Mill Effluent

Heavy metals are categorized based on their high density, atomic weight, atomic number and molecular weight. Lewis acids property of metal ions results in covalent complex formation with different ligands in humans and other living forms which make metals nondegradable and cause toxicity (Duffus, 2002). Pulp and paper mill are categorized as one of the 12 most polluting industries in India which release environmentally hazardous effluent containing heavy metals and other organic toxicants (Verma et al., 2005). According to World Health Organization cadmium, cobalt, copper, chromium, lead, nickel and zinc are the metals of most immediate concern. Because of high toxicity they require suitable treatment prior to discharge into the environment (Zaied et al., 2008; Rao et al., 2005). The conventional processes used for metal removal are sometimes restricted because of technical or economical constraints (Akar and Tunali, 2006). Biological methods through bioaccumulation and biosorption for heavy metal removal from industrial wasted streams provide an attractive alternative to conventional process (Hussein et al., 2004; Kiran et al., 2005). Microorganisms including fungi can be explored for heavy metals removal because of their potential application in protection of environment and recovery of precious metals (Vimala and Das, 2009; Sag and Kutsal, 2000). Metal polluted environment contains fungi which have adapted to toxic concentration of heavy metals have become metal resistant (Jaeckel et al., 2005). Metals uptake by living fungi depends on species, culture conditions, metal concentration and cells in the solution (Melgar et al., 2007). Little is known about the removal of lead, cadmium, copper and nickel from aqueous solution using Aspergillus sp. (Srivastava and Thakur, 2006). The paper deals with heavy metals accumulation potency of two specis of Aspergillus.