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Biotransformation of halogenated compounds by lyophilized cells of Rhodococcus erythropolis in a continuous solid-gas biofilter

Erable, Benjamin and Maugard, Thierry and Goubet, Isabelle and Lamare, Sylvain and Legoy, Marie Dominique Biotransformation of halogenated compounds by lyophilized cells of Rhodococcus erythropolis in a continuous solid-gas biofilter. (2005) Process Biochemistry, 40 (1). 45-51. ISSN 1359-5113

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Official URL: http://dx.doi.org/10.1016/j.procbio.2003.11.031

Abstract

The irreversible hydrolysis of 1-chlorobutane to 1-butanol and HCl by lyophilized cells of Rhodococcus erythropolis NCIMB 13064, using a solid–gas biofilter, is described as a model reaction. 1-Chlorobutane is hydrolyzed by the haloalkane dehalogenase from R. erythropolis. A critical water thermodynamic activity (aw ) of 0.4 is necessary for the enzyme to become active and optimal dehalogenase activity for the lyophilized cells is obtained for a aw of 0.9. A temperature of reaction of 40 ◦ C represents the best compromise between stability and activity. The activation energy of the reaction was determined and found equal to 59.5 kJ/mol. The absence of internal diffusional limitation of substrates in the biofilter was observed. The apparent Michaelis–Menten constants Km and Vmax for the lyophilized cells of R. erythropolis were 0.011 (1-chlorobutane thermodynamic activity, aClBut ) and 3.22 µmoles/min g of cell, respectively. The activity and stability of lyophilized cells were dependent on the quantity of HCl produced. Since possible modifications of local pH by the HCl product, pH control by the addition of volatile Lewis base (triethylamine) in the gaseous phase was employed. Triethylamine plays the role of a volatile buffer that controls local pH and the ionization state of the dehalogenase and prevents inhibition by Cl− . Finally, cells broken by the action of the lysozyme, were more stable than intact cells and more active. An initial reaction rate equal to 4.5 µmoles/min g of cell was observed.

Item Type:Article
Additional Information:Thanks to Elsevier editor. The definitive version is available at http://www.sciencedirect.com The original PDF of the article can be found at Process Biochemistry website : http://dx.doi.org/10.1016/j.procbio.2003.11.031
Audience (journal):International peer-reviewed journal
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Institution:French research institutions > Centre National de la Recherche Scientifique - CNRS (FRANCE)
Other partners > Université de La Rochelle (FRANCE)
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Deposited By: Benjamin ERABLE
Deposited On:15 Jan 2013 12:17

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