Effects of chlorobenzoate transformation on the Pseudomonas testosteroni biphenyl and chlorobiphenyl degradation pathway

Journal Article · Sat Feb 01 04:00:00 EST 1992 · Applied and Environmental Microbiology; (United States)

OSTI ID:5488070

Sondossi, M; Sylvestre, M; Ahmad, D ^[1]

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1. Univ. du Quebec, Varennes (Canada)

Bacterial conversion of biphenyl (BP) and chlorobiphenyls (CBPs) to benzoates and chlorobenzoates (CBAs) proceeds by introduction of molecular oxygen at the 2,3 position, followed by a 1,2-meta cleavage of the molecule. Complete mineralization of CBPs requires the presence of two sets of genes, one for the transformation of CBPs into CBAs and a second for the degradation of CBAs. It has been shown previously that removal of the CBAs produced from the degradation of CBPs is essential for efficient degradation of CBPs. In this study the authors confirmed that CBAs inhibit BP and CBP transformation in Pseudomonas testosteroni B-356. Among the three monochlorobenzoates tested, 3-chlorobenzoate was the most effective inhibitor. Furthermore, they found that in strain B-356, CBA transformation is controlled by BP-induced oxygenases that are not present in benzoate-grown cells. They found that this BP-linked CBA transformation pathway transformed CBAs produced from CBPs into several metabolites, including chlorocatechols and corresponding muconic semialdehydes. These metabolites inhibited the 2,3-dihydroxybiphenyl 1,2-dioxygenase, while CBAs by themselves had no effect on this enzyme. Therefore, on the basis of this and other observations, it appears that when CBAs produced from CBPs accumulate in the growth medium, they are converted into unproductive metabolites that reduce the flux of the BP and CBP degradation pathway.

• OSTI ID: 5488070
• Journal Information: Applied and Environmental Microbiology; (United States), Journal Name: Applied and Environmental Microbiology; (United States) Vol. 58:2; ISSN 0099-2240; ISSN AEMID
• Country of Publication: United States
• Language: English

Related Subjects

550500* -- Metabolism
59 BASIC BIOLOGICAL SCIENCES
AROMATICS
BACTERIA
BIODEGRADATION
BIOLOGICAL PATHWAYS
CHEMICAL REACTIONS
CHLORINATED AROMATIC HYDROCARBONS
DECOMPOSITION
ENZYMES
GENES
HALOGENATED AROMATIC HYDROCARBONS
METABOLITES
MICROORGANISMS
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
OXIDOREDUCTASES
OXYGENASES
PROTEINS
PSEUDOMONAS