Taguchi approach significantly increases bioremediation process efficiency: a case study with Hg (II) removal by Pseudomonas aeruginosa

• Published in: Letters in applied microbiology Vol. 45; no. 1; pp. 36 - 41
• Main Authors: Tupe, S.G, Rajwade, J.M, Paknikar, K.M
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.07.2007; Blackwell Publishing Ltd; Blackwell Science
• Subjects: Biological and medical sciences; Biomass; Bioreactors; bioremediation; Computer Simulation; Culture Media; Fundamental and applied biological sciences. Psychology; Hydrogen-Ion Concentration; Mercuric Chloride - metabolism; mercury; Microbiology; parameters optimization; Pseudomonas aeruginosa; Pseudomonas aeruginosa - growth & development; Pseudomonas aeruginosa - isolation & purification; Pseudomonas aeruginosa - metabolism; Sewage - microbiology; Software; Taguchi approach; Temperature; Water Pollutants, Chemical - metabolism; Water Purification - methods; Pseudomonadales; Taguchi approach; Efficiency; Applied microbiology; Bacteria; Pseudomonadaceae; Pseudomonas aeruginosa; Bioremediation; Operating process; Mercury; Optimization; parameters optimization
• ISSN: 0266-8254; 1472-765X
• DOI: 10.1111/j.1472-765X.2007.02152.x

Optimization of process parameters for mercury removal by an Hg (II)-reducing Pseudomonas aeruginosa strain. A strain of Ps. aeruginosa was found to reduce 10 mg l⁻¹ Hg (II) to Hg⁰ with 70% efficiency in 24 h. To optimize process performance, a statistical tool - Taguchi design of experiments (DOE) - was used to carry out 18 well-defined experiments (L18 Orthogonal array) with eight variable parameters (viz. agitation, temperature, pH, carbon source, medium volume: flask volume ratio and concentrations of Hg (II), ammonium sulfate and yeast extract). When data obtained were analyzed using specialized software for Taguchi design, Qualitek-4 (Nutek Inc., MI, USA), Hg (II) reduction efficiency was predicted to be 95% in 24 h under the optimized process parameters (also suggested by the software). In the validation experiment, Hg (II) removal of 99·29% in 24 h was indeed obtained. Using Taguchi DOE, Hg (II) reduction (and hence its removal) using Ps. aeruginosa could be improved by 29·3%. Taguchi approach could be employed as an efficient and time-saving strategy for parameter optimization in bioremediation processes.