Environmental Engineering Reference
In-Depth Information
degradedTPTtoMPTviaDPTanddegradedDPTandDBTtoMPTandMBT,
respectively.
The TPT-degrading activity of F-I was remarkably inhibited by the add-
ition of metal ions chelated with pyoverdin. On the other hand, the activity
of the F-I was increased 13- and 8-fold by the addition of Cu
2+
and Sn
4+
,
respectively. These results suggest that metal-chelating ligands common to
pyoverdins may play important roles in the Sn-C cleavage of the organotin
compounds in both the metal-free and metal-complexed states as described
below (see Fig. 6) [130].
Using a screening technique based on pyrocatechol violet colorimetry for
the detection of TPT metabolites, DPT, MPT, and inorganic tin were iso-
lated. An isolated strain CNR22,
Burkholderia cepacia
was identified. The
organotin degradation activity was observed in the culture supernant of
the strain CNR22 grown without organotin; the reaction was catalyzed by
low-molecular-mass iron chelators of a microbial origin [133]. These four
substances are two azotochelins and two ornibactins [134]. The azotochelins
Fig. 6
The structure of pyoverdin from
Pseudomonas chlororaphis
CRN 15 possessing
TPT degradation activity. Proposed TPT and DPT degradation pathway involving the
complexation with pyoverdin.
Scheme I
, the physiological Fe-complexation of pyoverdin;
scheme II
, the potential organotin cometabolism pathway by pyoverdin [131]
