Polychlorinated biphenyls (PCBs) present in the commercial mixture Del
or 103 were transformed by hairy root culture of Solanum nigrum. Plant
growth regulators kinetin, 2,4-dichlorophenoxy-acetic acid, benzylami
nopurin and/or naphthaleneacetic acid, influenced the cells' growth an
d 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 conversion than did older inocula (37, 68 days) wh
ile biomass increase was much higher using young inoculum. With increa
sing 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.