skip to main content

Title: TCE degradation by toluene/benzene monooxygenase of Pseudomonas aeruginosa JI104 and Escherichia coli recombinant

Pseudomonas aeruginosa JI104 incorporates more than three degradation pathways for aromatic compounds such as benzene, toluene, and xylene. A dioxygenase and two monooxygenases were cloned in Escherichia coli XL1-Blue. The dioxygenase yielding cis-toluene dihydrodiol and one of the monooxygenases producing o-cresol from toluene did not exhibit conspicuous activity in trichloroethylene (TCE) oxygenation, although DNA sequencing proved that the former enzyme was an isozyme of toluene dioxygenase of the known TCE decomposer P.putida F1. The other toluene/benzene monooxygenase that could generate o-, m-, and p-cresol simultaneously from toluene showed TCE oxygenation activity resulting in TCE decomposition in E. coli. The activity was inhibited competitively by toluene, ethylbenzene, and o- and m-xylene: their inhibition constants were greater than those of propylbenzene and p-xylene. When the E. coli recombinant harboring the monooxygenase was induced by isopropyl {beta}-D-thiogalactopyranoside (IPTG) and incubated in the absence of toluene, TCE degradation activity decreased during incubation, compared to that with toluene. Toluene probably controlled the lifetime of the enzyme.
Authors:
 [1] ;  [2]
  1. National Univ. of Yokohama (Japan). Div. of Bioengineering
  2. Univ. of Tokyo (Japan). Dept. of Biochemistry and Biotechnology
Publication Date:
OSTI Identifier:
474277
Report Number(s):
CONF-950483-
ISBN 1-57477-005-5; TRN: IM9723%%167
Resource Type:
Conference
Resource Relation:
Conference: 3. international in situ and on-site bioreclamation symposium, San Diego, CA (United States), 24-27 Apr 1995; Other Information: PBD: 1995; Related Information: Is Part Of Bioremediation of chlorinated solvents; Hinchee, R.E.; Leeson, A. [eds.] [Battelle Memorial Inst., Columbus, OH (United States)]; Semprini, L. [ed.] [Oregon State Univ., Corvallis, OR (United States)]; PB: 348 p.; Bioremediation, Volume 3(4)
Publisher:
Battelle Press, Columbus, OH (United States)
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; BIODEGRADATION; REMEDIAL ACTION; CHLORINATED ALIPHATIC HYDROCARBONS; BENZENE; TOLUENE; XYLENES; IN-SITU PROCESSING; BIOLOGICAL PATHWAYS; OXYGENASES; METABOLISM; ENZYME INHIBITORS