title: Response surface methodology for process parameter optimization of hydrogen yield by the metabolically engineered strain Escherichia coli DJT135.
abstract: Metabolically engineered microbial strains can be usefully employed to give higher yields, but this also requires development of a suitable bioprocess. Maximization of product yield during fermentation requires that a number of process parameters, some of which may interact, be optimized. Here we report the effects of different fermentative process conditions; pH, temperature and glucose concentration, on the molar hydrogen yield by a genetically optimized Escherichia coli strain, DJT135. In order to simultaneously reduce the number of the experiments, and to obtain the interactions between the variables important for achieving maximum hydrogen production, a 3(K) full factorial Box-Behnken design and response surface methodology (RSM) were employed for experimental design and analysis. A maximum molar hydrogen yield of 1.69 mol H(2)mol(-1) glucose was obtained under the optimal conditions of 75 mM glucose, 35 degrees C and pH 6.5. Thus, RSM with Box-Behnken design is a useful method for achieving higher molar hydrogen yields by metabolically engineered organisms.
authors.affiliation: Département de Microbiologie et Immunologie, Université de Montréal, CP 6128 Succursale Centre-ville, Montréal, Québec, Canada.
authors.forename: Dipankar
authors.initials: D
authors.lastname: Ghosh
authors.forename: Patrick C
authors.initials: PC
authors.lastname: Hallenbeck
mesh_terms: D056804:Biofuels; D019149:Bioreactors; D001709:Biotechnology / Q000379:methods*; D004926:Escherichia coli / Q000378:metabolism*; D005285:Fermentation; D005818:Genetic Engineering / Q000379:methods; D005947:Glucose / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007218:Industrial Microbiology / Q000379:methods; D013499:Surface Properties; D013696:Temperature
chemical_list: D056804:Biofuels; D006859:Hydrogen; D005947:Glucose