Document Detail

Temperature and pH effect on the microbial reductive transformation of pentachloronitrobenzene.
MedLine Citation:
PMID:  17552540     Owner:  NLM     Status:  MEDLINE    
The effect of pH and temperature on the microbial reductive transformation of pentachloronitrobenzene (PCNB), an organochlorine fungicide, was investigated with a mixed fermentative/methanogenic culture developed from a contaminated estuarine sediment. Culture series were incubated at a temperature range from 4 to 45 degrees C at pH 6.9+/-0.1 and at a pH range from 2.7+/-0.1 to 7.6+/-0.1 at 22 degrees C. Significant differences were observed in terms of biotransformation rate, extent, and products as a function of temperature. Incubation at different pH values resulted in differences in biotransformation rate and extent, but not in terms of products formed. PCNB (3 microM) was transformed to pentachloroaniline (PCA) in all culture series. However, sequential dechlorination of PCA was observed only at a temperature range from 4 to 35 degrees C and at a pH range from 6.2+/-0.1 to 7.6+/-0.1. The highest PCA dechlorination rate was observed at 22 degrees C and at pH 7.6+/-0.1. The effect of temperature on the PCA dechlorination rate was modeled using an Arrhenius relationship, which accounts for both enzyme activation and deactivation. The dechlorination of PCA and chlorinated aniline intermediates was simulated using a branched-chain Michaelis-Menten model, and kinetic constants were determined.
Didem Okutman Tas; Spyros G Pavlostathis
Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.     Date:  2007-06-07
Journal Detail:
Title:  Journal of agricultural and food chemistry     Volume:  55     ISSN:  0021-8561     ISO Abbreviation:  J. Agric. Food Chem.     Publication Date:  2007 Jul 
Date Detail:
Created Date:  2007-07-03     Completed Date:  2007-09-19     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0374755     Medline TA:  J Agric Food Chem     Country:  United States    
Other Details:
Languages:  eng     Pagination:  5390-8     Citation Subset:  IM    
School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0512, USA.
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MeSH Terms
Bacteria / metabolism*
Fungicides, Industrial / metabolism*
Hydrogen-Ion Concentration
Nitrobenzenes / metabolism*
Reg. No./Substance:
0/Fungicides, Industrial; 0/Nitrobenzenes; 82-68-8/quintozene

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