title: Experimental study on Cr (V) reduction by Pseudomonas aeruginosa.
abstract: Investigation on Cr(V) reduction was conducted using Pseudomonas aeruginosa. The study demonstrated that the Cr(VI) can be effectively reduced to Cr(III) by Pseudomonas aeruginosa. The effects of the factors affecting Cr(VI) reduction rate including carbon source type, pH, initial Cr(VI) concentration and amount of cells inoculum were thoroughly studied. Malate was found to yield maximum biotransformation, followed by succinate and glucose, with the reduction rate of 60.86%, 43.76% and 28.86% respectively. The optimum pH for Cr(VI) reduction was 7.0, with reduction efficiency of 61.71% being achieved. With the increase of initial Cr(VI) concentration, the rate of Cr(VI) reduction decreased. The reduction was inhibited strongly when the initial Cr(VI) concentration increased to 157 mg/L. As the amount of cells inoculum increased, the rate of Cr(VI) reduction also increased. The mechanism of Cr(VI) reduction and final products were also analysed. The results suggested that the soluble enzymes appear to be responsible for Cr(VI) reduction by Pseudomonas aeruginosa, and the reduced Cr(III) was not precipitated in the form of Cr(OH)3.
authors.affiliation: Department of Environmental Science and Engineering, Hunan University, Changsha 410082, China.
authors.forename: Yun-Guo
authors.initials: YG
authors.lastname: Liu
authors.forename: Wei-Hua
authors.initials: WH
authors.lastname: Xu
authors.forename: Guang-Ming
authors.initials: GM
authors.lastname: Zeng
authors.forename: Chun-Fang
authors.initials: CF
authors.lastname: Tang
authors.forename: Cheng-Feng
authors.initials: CF
authors.lastname: Li
mesh_terms: D001711:Biotransformation; D002244:Carbon / Q000378:metabolism; D002857:Chromium / Q000378:metabolism*; D003124:Colorimetry; D005947:Glucose; D006863:Hydrogen-Ion Concentration; D008293:Malates; D011550:Pseudomonas aeruginosa / Q000378:metabolism*; D019802:Succinic Acid
chemical_list: D008293:Malates; D002857:Chromium; C074702:chromium hexavalent ion; D002244:Carbon; C030298:malic acid; D019802:Succinic Acid; D005947:Glucose