Biomaterial Database

Graphical estimation of the dual-enzyme kinetic parameters for Cr(VI) reduction. 2006

Md Akram Hossain

Civil and Environmental Engineering, Washington State University, 2710 University Drive, Richland, WA 99354, USA. ahossain@tricity.wsu.edu

Chromium(VI) (Cr(VI)) contamination of soil and groundwater is a major environmental concern. Bioreduction of Cr(VI) by Shewanella oneidensis MR-1 (MR-1) can be considered a feasible option to reduce the toxic and mobile Cr(VI) to the less toxic and less mobile chromium(III) (Cr(III)). The reaction rate expression for Cr(VI) reduction is nonlinear and the rate constants are evaluated by employing nonlinear optimization techniques. The outcome of the optimization techniques, in general, depends on the initial estimate of the kinetic parameters which is not always available. A graphical approach based on sound mathematical reasoning has been developed which is accurate, simpler to use, and can provide the best initial estimate for nonlinear optimization.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008433	Mathematics	The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Mathematic
D010084	Oxidation-Reduction	A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).	Redox,Oxidation Reduction
D002857	Chromium	A trace element that plays a role in glucose metabolism. It has the atomic symbol Cr, atomic number 24, and atomic weight 52. According to the Fourth Annual Report on Carcinogens (NTP85-002,1985), chromium and some of its compounds have been listed as known carcinogens.
D012988	Soil Microbiology	The presence of bacteria, viruses, and fungi in the soil. This term is not restricted to pathogenic organisms.	Microbiology, Soil
D012989	Soil Pollutants	Substances which pollute the soil. Use for soil pollutants in general or for which there is no specific heading.	Soil Pollutant,Pollutant, Soil,Pollutants, Soil
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor
D020592	Shewanella	A genus of gram-negative, facultatively anaerobic rods. It is a saprophytic, marine organism which is often isolated from spoiling fish.