Biotransformation kinetics of Pseudomonas putida for cometabolism of phenol and 4-chlorophenol in the presence of sodium glutamate

Authors
Citation
Sj. Wang et Kc. Loh, Biotransformation kinetics of Pseudomonas putida for cometabolism of phenol and 4-chlorophenol in the presence of sodium glutamate, BIODEGRADAT, 12(3), 2001, pp. 189-199
Citations number
21
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biotecnology & Applied Microbiology
Journal title
BIODEGRADATION
ISSN journal
0923-9820 → ACNP
Volume
12
Issue
3
Year of publication
2001
Pages
189 - 199
Database
ISI
SICI code
0923-9820(2001)12:3<189:BKOPPF>2.0.ZU;2-W
Abstract
A kinetic model to describe the degradation of phenol and cometabolic trans formation of 4-chlorophenol (4-cp) in the presence of sodium glutamate (SG) has been developed and validated experimentally. The integrated model acco unts for cell growth, toxicity of 4-cp, cross-inhibitions among the three s ubstrates, and the different roles of the specific growth substrate (phenol ) and the conventional carbon source (SG) in the cometabolism of 4-cp. In t his ternary substrate system, the overall phenol degradation and 4-cp trans formation rates are greatly enhanced by the addition of SG since SG is able to attenuate the toxicity of 4-cp and therefore increase the cell growth r ate. Model analysis indicates that the maximum specific degradation rate of phenol (0.819 mg (mg.h)(-1)) is lowered by SG by up to 46% whereas the spe cific transformation rate of 4-cp is not directly affected by the presence of SG. The competitive inhibition coefficient of 4-cp to phenol degradation (K-i,K-cp) and that of phenol to 4-cp transformation (K-i,K-ph) were deter mined to be 6.49 mg l(-1) and 0.193 mg l(-1), respectively, indicating that phenol imposes much larger competitive inhibition to 4-cp transformation t han the converse. The model developed can simultaneously predict phenol deg radation and 4-cp transformation, and is useful for dealing with cometaboli sm involving multiple substrates.