Degradation of polychlorinated biphenyls by hairy root culture of Solanum nigrum

Polychlorinated biphenyls (PCBs) present in the commercial mixture Delor 103 were transformed by hairy root culture of Solanum nigrum. Plant growth regulators kinetin, 2,4-dichlorophenoxy-acetic acid, benzylaminopurin and/or naph-thaleneacetic acid, influenced the cells' growth and transformation of PCBs in a different manner. The cells were able to transform PCBs even if they ceased growing. Young inoculum (16 days) had a 20% lower PCB conversionthan did older inocula (37, 68 days) while biomass increase was much higher using young inoculum. With increasing size of inoculum, transformation of PCBs was stimulated. After 30 days of incubation the average amount of residual PCBs was 40% of the controls at initial PCB concentration of 100 ppm.