Hexavalent chromium reduction by Acinetobacter haemolyticus isolated from heavy-metal contaminated wastewater.
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.
Zakaria
Zainul Akmar
ZA
Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia.
Zakaria
Zainoha
Z
Surif
Salmijah
S
Ahmad
Wan Azlina
WA
D000150:Acinetobacter / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D000838:Anions / Q000494:pharmacology; D002244:Carbon / Q000494:pharmacology; D002857:Chromium / Q000378:metabolism*; D006358:Hot Temperature; D007220:Industrial Waste; D019216:Metals, Heavy / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D010084:Oxidation-Reduction; D019810:Sodium Azide / Q000494:pharmacology; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D018508:Water Purification / Q000379:methods
D000838:Anions; D007220:Industrial Waste; D019216:Metals, Heavy; D014874:Water Pollutants, Chemical; D002857:Chromium; C074702:chromium hexavalent ion; D002244:Carbon; D019810:Sodium Azide