title: Biosorption and bioreduction of Cr(VI) by locally isolated Cr-resistant bacteria.
abstract: Cr(VI) biosorption and bioreduction ability of locally isolated Cr-resistant bacteria was investigated using the shake-flask technique. A mixture of S. epidermidis and B. cereus showed the highest minimum inhibitory concentration (MIC) level at 750 mg/L Cr(VI) followed by S. aureus and Bacillus sp. of 250 mg/L, and A. haemolyticus of 70 mg/L. From the Langmuir adsorption isotherm, the treatment of cells with heat-acid resulted in the highest amount of Cr(VI) adsorped (78.25 mg/g dry wt. for S. epidermidis) compared to heat-acetone (67.93 mg/g dry wt. Bacillus sp.), heat only (36.05 mg/g dry wt. S. epidermidis) or untreated cells (45.40 mg/g dry wt. S. epidermidis and B. cereus). FTIR analysis showed the involvement of amine groups in Cr(VI) adsorption. In the bioreduction study, A. haemolyticus was able to completely reduce Cr(VI) up to 50 mg/L.
authors.affiliation: Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia. zainul@kimia.fs.utm.my
authors.forename: Z A
authors.initials: ZA
authors.lastname: Zakaria
authors.forename: N
authors.initials: N
authors.lastname: Aruleswaran
authors.forename: S
authors.initials: S
authors.lastname: Kaur
authors.forename: W A
authors.initials: WA
authors.lastname: Ahmad
mesh_terms: D000327:Adsorption; D001419:Bacteria / Q000378:metabolism*; D001673:Biodegradation, Environmental; D018533:Biomass; D002857:Chromium / Q000737:chemistry / Q000378:metabolism*; D010084:Oxidation-Reduction; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000378:metabolism
chemical_list: D014874:Water Pollutants, Chemical; D002857:Chromium