COMPARISON OF THE DEGRADATION PATTERNS OF POLYCHLORINATED BIPHENYL CONGONERS IN AROCLORS BY PSEUDOMONAS STRAIN LB400 AFTER GROWTH ON VARIOUS CARBON-SOURCES

Resting cells of Pseudomonas strain LB400, grown on biphenyl, transfor med 80, 50, and 17% of Aroclor 1242, 1254, and 1260, respectively. Res ting cells grown on glucose or glycerol also transformed these polychl orinated biphenyl (PCB) mixtures to the extent of 60, 35, and 9% for A roclors 1242, 1254, and 1260, respectively. Time courses of the transf ormation of the separated individual congeners in the Aroclors were pl otted and used to determine the transformation rate constants (k). By analysis of the rate constants, it was concluded that the order of deg radation of the different congeners in an Aroclor were similar regardl ess of the growth substrate. In general, k values for the conversion o f a particular congener were lower for cells grown on glucose or glyce rol compared with cells grown on biphenyl. Generally, k values for the transformation of the same congener in different Aroclors were not th e same: rate constants had highest values for the congener in Aroclor 1242 and lowest values in Aroclor 1260. The data allowed congeners to be grouped according to their relative rates of degradation. The ratio of k values for transformation of individual congeners in Aroclors by cells grown on biphenyl and glucose were not constant.