Abstract
A bacterial strain capable of degrading triphenyltin (TPT) was isolated using a screening technique based on pyrocatechol violet colorimetry for the detection of TPT metabolites, diphenyltin, monophenyltin, and inorganic tin. The isolated strain, CNR22, was identified as Burkholderia cepacia. Strain CNR22 was also found to degrade tributyltin (TBT). After 240-h incubation, a strain CNR22 culture containing additional carbon sources, glucose and L-valine, showed the accumulation of 42 μmol·l-1 inorganic tin and 17 μmol·l-1 monobutyltin as the main metabolite from 100 μmol·l-1 each of TPT and TBT, respectively. The organotin degradation activity was observed in the culture supernatant of strain CNR22 grown without organotin; the reaction was catalyzed by low-molecular-mass iron chelators of microbial origin. These substances degraded TPT and TBT to the corresponding monoorganotin. The monophenyltin (or monophenyltin-chelator complex) produced could be further converted to an inorganic tin (or an inorganic tin-chelator complex) in a sterile medium.
