Tolerance of phenol-utilizing bacteria to heavy metals in the Aba River sediments

Abstract

Bacteria strains were isolated from sediment of tropical fresh water River that receives industrial discharges and were screened for utilization of phenol as the sole carbon and energy. Pseudomonas, Arthrobacter and Staphylococcus species were able to utilize 10.0 mM of phenol while Escherichia and Bacillus species were unable to utilize more than 5.0 mM of phenol. Metal-resistant bacteria were selected and minimal inhibitory concentrations (MIC) of heavy metals for each isolate were determined using tube dilution method. On the bases of MICs, all the strains showed tolerance to Zn, Cu, Cd, Pb, Ni, Co, Cr and Hg. The bacterial strains exhibited varying degrees of tolerance depending on the metal type. Copper and Nickel were best tolerated metals. Mercury and Zinc were the most toxic metals for all bacteria.

Keywords: Heavy metal, phenol-utilizing bacteria, Aba River, sediment

International Journal of Natural and Applied Sciences, 6(1): 55-61, 2010