Hexavalent chromium reduction by Acinetobacter haemolyticus isolated from heavy-metal contaminated wastewater

J Hazard Mater. 2007 Jul 19;146(1-2):30-8. doi: 10.1016/j.jhazmat.2006.11.052. Epub 2006 Nov 30.

Abstract

Possible application of a locally isolated environmental isolate, Acinetobacter haemolyticus to remediate Cr(VI) contamination in water system was demonstrated. Cr(VI) reduction by A. haemolyticus seems to favour the lower concentrations (10-30 mg/L). However, incomplete Cr(VI) reduction occurred at 70-100 mg/L Cr(VI). Initial specific reduction rate increased with Cr(VI) concentrations. Cr(VI) reduction was not affected by 1 or 10 mM sodium azide (metabolic inhibitor), 10 mM of PO(4)3-, SO4(2-), SO(3)2-, NO3- or 30 mg/L of Pb(II), Zn(II), Cd(II) ions. However, heat treatment caused significant dropped in Cr(VI) reduction to less than 20% only. A. haemolyticus cells loses its shape and size after exposure to 10 and 50 mg Cr(VI)/L as revealed from TEM examination. The presence of electron-dense particles in the cytoplasmic region of the bacteria suggested deposition of chromium in the cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acinetobacter / drug effects
  • Acinetobacter / growth & development
  • Acinetobacter / metabolism*
  • Anions / pharmacology
  • Carbon / pharmacology
  • Chromium / metabolism*
  • Hot Temperature
  • Industrial Waste
  • Metals, Heavy / pharmacology
  • Microbial Sensitivity Tests
  • Oxidation-Reduction
  • Sodium Azide / pharmacology
  • Waste Disposal, Fluid / methods
  • Water Pollutants, Chemical / metabolism*
  • Water Purification / methods

Substances

  • Anions
  • Industrial Waste
  • Metals, Heavy
  • Water Pollutants, Chemical
  • Chromium
  • chromium hexavalent ion
  • Carbon
  • Sodium Azide