Propachlor removal by Pseudomonas strain GCH1 in an immobilized-cell system.
A bacterial strain capable of growing on propachlor (2-chloro-N-isopropylacetanilide) was isolated from soil by using enrichment and isolation techniques. The strain isolated, designated GCH1, was classified as a member of the genus Pseudomonas. Washed-cell suspensions of strain GCH1 accumulated N-isopropylacetanilide, acetanilide, acetamide, and catechol. Pseudomonas strain GCH1 grew on propachlor with a generation time of 4.2 h and a rate of substrate utilization of 1.75 +/- 0.15 micromol h(-1). Gene expression did not require induction but was subject to catabolite expression. Acetanilide was a growth substrate with a yield of 0.56 +/- 0.02 mg of protein micromol(-1). GCH1 strain cells were immobilized by adsorption onto a ceramic support and were used as biocatalysts in an immobilized cell system. Propachlor elimination reached 98%, with a retention time of 3 h and an initial organic load of 0.5 mM propachlor. The viability of immobilized cells increased 34-fold after 120 days of bioreactor operation.
Martín
M
M
Departamento Bioquimica y Biologia Molecular IV, 28040 Madrid, Spain. margamar@eucmax.sim.ucm.es
Mengs
G
G
Plaza
E
E
Garbi
C
C
Sánchez
M
M
Gibello
A
A
Gutierrez
F
F
Ferrer
E
E
D000081:Acetamides; D000083:Acetanilides / Q000378:metabolism*; D001673:Biodegradation, Environmental; D019149:Bioreactors; D018914:Cells, Immobilized; D004785:Environmental Pollutants / Q000378:metabolism*; D006540:Herbicides / Q000378:metabolism*; D011549:Pseudomonas / Q000166:cytology / Q000378:metabolism*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000378:metabolism
D000081:Acetamides; D000083:Acetanilides; D004785:Environmental Pollutants; D006540:Herbicides; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; C011088:propachlor; C030686:acetamide