| dc.description.abstract | Preliminary investigations on the Environmental Chemistry of Methoxychlor [2,2-bis (p - methoxyphenyl)-1,1,1- trichloroethane], a potential DDT replacement, have been conducted with emphasis on its degradation
by micro-organisms.
Literature reports on the microbial degradation of
methoxychlor are scarce, and in those reports the major
emphasis is on the interaction of this pesticide with
bacteria. Therefore, studies concerning the interaction
of micro-organisms with methoxychlor were initiated.
The micro-organisms used were the common soil fungi:
Trichoderma viride, Mortierella isabellina, M,pusilla,
and the aquatic fungus Saprolegnia parasitica. Also because of anomalous results reported in the literature
on the possible biodegradation of methoxychlor by a
bacterium, Klebsiella pneumoniae, this aspect of the
environmental fate of methoxychlor was reinvestigated.
Known metabolites of methoxychlor required for
this study were synthesized. Some of the synthetic
methods were slightly modified so as to improve yields
or facilitate purification of the products. Also to
facilitate the identification of possible degradation
products, the spectroscopic properties (MS and NMR) of these various methoxychlor derivatives were studied.
A gas chromatographic method was developed for the
analyses of these compounds and included the silylation
of the phenolic compounds.
Little is known about the fungitoxicity of methoxychlor
or its metabolites, thus such fungitoxicity studies
were carried out. It was found that the dihydroxy
methoxychlor derivatives were more toxic than the dimethoxy
methoxychlor derivatives, towards the fungi used. In
fungal metabolism studies with methoxychlor, M.isabellina,
M.pusilla and S.parasitica were found to be capable of
partially degrading methoxychlor, by effecting the ether
cleavage of the methoxy groups in the molecule. T.viride
did not effect a similar alteration of the methoxychlor
molecule but appears to produce at least one metabolite
of methoxychlor. It is suggested that this metabolite
is a glycoside. No evidence was found to indicate that
the fungi studied attacked the central part of the
methoxychlor molecule.
K,pneumoniae was found to be capable of the reductive
dechlorination of methoxychlor and also its hydroxy
derivative [2,2-bis (p - hydroxyphenyl) -1,1,1- trichloroethane]. It was also established that this bacterium does not effect the cleavage of the methoxy groups in methoxychlor.
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