Aerobic degradation of 2,4,6-trichlorophenol by a microbial consortium - selection and characterization of microbial consortium.
A microbial consortium that efficiently degrades 2,4,6-TCP (2,4,6-trichlorophenol), as the sole source of carbon and energy under aerobic conditions was selected from municipal activated sludge. Six bacterial strains, designated S(1), S(2), S(3), S(4), S(5) and S(6), were isolated from the selected consortium and five were identified as Sphingomonas paucimobilis (S(2), S(3)), Burkholderia cepacia(S(4)), Chryseomonas luteola (S(5)) and Vibrio metschnikovii (S(6)). After prolonged cultivation followed by successive transfers, the consortium's degradation ability was improved and reached a specific degradation rate of 34 mg 2,4,6-TCP g(-1) dry weight h(-1) (about 51 mg 2,4,6-TCP g(-1) cell protein h(-1)). The soluble chemical oxygen demand, chloride and oxygen uptake balance data clearly indicate the complete dechlorination and mineralization of 2,4,6-TCP. The consortium's activity was not inhibited by 2,4,6-TCP concentrations <or=400 mg l(-1). The highest specific growth rate (micro(max) of 0.01 h(-1)) was achieved at 2,4,6-TCP concentration <or=200 mg l(-1), and the inhibition constant ( K(i)) was 610 mg l(-1) according to the Haldane inhibition kinetic model. An inoculum size up to 120 mg l(-1) cell dry weight is desirable in order to avoid a lag phase and to allow faster degradation of 2,4,6-TCP.
Kharoune
L
L
Ecole Polytechnique of Montreal, Environmental Engineering, Department of Civil, Geological and Mining Engineering (CGM), P. O. Box 6079, Station Centre-ville Montreal (Quebec), Canada H3C 3A7. lynda.kharoune@polymtl.ca
Kharoune
M
M
Lebeault
J M
JM
D000332:Aerobiosis; D001419:Bacteria / Q000145:classification* / Q000378:metabolism*; D001673:Biodegradation, Environmental; D002733:Chlorophenols / Q000737:chemistry / Q000378:metabolism*; D012988:Soil Microbiology
D002733:Chlorophenols; C024564:2,4,6-trichlorophenol