Metabolism of both 4-chlorobenzoate and toluene under denitrifying conditions by a constructed bacterial strain

Journal Article · Tue Mar 01 04:00:00 EST 1994 · Applied and Environmental Microbiology; (United States)

OSTI ID:7199130

Coschigano, P W; Haeggblom, M M; Young, L Y ^[1]

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1. Rutgers, the State Univ. of New Jersey, New Brunswick, NJ (United States)

T1, a denitrifying bacterium originally isolated for its ability to grow on toluene, can also metabolize 4-hydroxybenzoate and other aromatic compounds under denitrifying conditions. A cosmid clone carrying the three genes that code for the 4-chlorobenzoate dehalogenase enzyme complex isolated from the aerobic bacterium Pseudomonas sp. strain CBS3 was successfully conjugated into strain T1. The cloned enzyme complex catalyzes the hydrolytic dechlorination of 4-chlorobenzoate to 4-hydroxybenzoate. Since molecular oxygen is not required for the dehalogenation reaction, the transconjugate strain of T1 (T1-pUK45-10C) was able to grow on 4-chlorobenzoate in the absence of O[sub 2] under denitrifying conditions. 4-Chlorobenzoate was dehalogenated to 4-hydroxybenzoate, which was then further metabolized by strain T1. The dehalogenation and metabolism of 4-chlorobenzoate were nitrate dependent and were coupled to the production of nitrite and nitrogen gas. 4-Bromobenzoate was also degraded by this strain, while 4-iodobenzoate was not. Additionally, when T1-pUK45-10C was presented with a mixture of 4-chlorobenzoate and toluene, simultaneous degradation of the compounds was observed. These results illustrate that dechlorination and degradation of aromatic xenobiotics can be mediated by a pure culture in the absence of oxygen. Futhermore, it is possible to expand the rand of xenobiotic substrates degradable by an organism, and it is possible that concurrent metabolism of these substrates can occur. 39 refs., 4 figs., 2 tabs.

• OSTI ID: 7199130
• Journal Information: Applied and Environmental Microbiology; (United States), Journal Name: Applied and Environmental Microbiology; (United States) Vol. 60:3; ISSN AEMIDF; ISSN 0099-2240
• Country of Publication: United States
• Language: English

Related Subjects

560300* -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ALKYLATED AROMATICS
ANAEROBIC CONDITIONS
AROMATICS
BACTERIA
BIODEGRADATION
CHEMICAL REACTIONS
DECHLORINATION
DECOMPOSITION
DEHALOGENATION
HYDROCARBONS
MICROORGANISMS
ORGANIC COMPOUNDS
PSEUDOMONAS
TOLUENE
XENOBIOTICS