Screening and Characterization of Heavy Metal Resistant Fungi for its Prospects in Bioremediation of Contaminated Soil

Abstract

Developing bioremediation processes for soils and effluents polluted by heavy metals is one of the serious concern. For the same, extensive screening for the bacteria having resistance to heavy metals such as lead, nickel, cobalt, chromium, copper, manganese and zinc was attempted. During this SGPB1, PGNI2, PGCO3, KGCR4, PGCU5, PGMN6 and SGZN7 isolates were obtained having maximum threshold level of tolerance to lead (0.26 mM), nickel (2.20 mM), cobalt (0.51 mM), chromium (0.01 mM), copper (0.09 mM), manganese (8.0 mM) and zinc (1.22 mM) respectively. Maximum growth of these isolates at threshold concentration of respective metal was found at pH 7.5 and temperature 30 o C except for the isolate PGCU 5 which showed maximum growth in presence of copper at 6 pH and 30 o C. Besides metal tolerance further antibiotic resistance pattern of these isolates were also studied. The results revealed that antibiotic resistance and metal resistance were highly coupled. Isolates PGNI2, PGCO3, KGCR4 and PGCU5 were found to have multiple antibiotic resistance. Based on the morphological, cultural and biochemical characterization, it was found that the isolates SGPB1, KGCR4 and SGZN7 were belong to genus Pseudomonas, the isolates PGNI2 and PGMN6 were belongs to Escherichia genus and isolates PGCO3 and PGCU5 were of Bacillus species.