The effect of bis(tributyltin) oxide on wood inhabiting microfungi

Abstract

The influence of above ambient temperatu$bn the activity of Tn.B.T.O. was investigated. Above ambient temperature is likely to accelerate the breakdown of the preservative inPinur* syIyesjjjA combination of antioxidant and preservative effects some reduction in breakdown suggesting that oxidative activity is, in part, responsible for such breakdown.
Prelininary erperiments into the effect of long and short wave ultraviolet radiation on the toxicity of Th.B.T.0. indicate that short wave radiation is generally more effective in detoxifying Th.B.T.0. in organic solvent, but evidence suggests that aqueous solutions may be more susceptible to longer wavelengths.
An oxygen electrode was utilised to test the effect of tributyltin on fungalrespiration and was found to be a useful tool for carrying out rapid determinations of this nature. TTI.B.T.O. subjected to above ambient temperature and ultraviolet ±adiation had a reduced effect upon the oxygen consumption of microfungi. Basidiomycete respiration was more sensitive to Tn.B.T.O. than that of the microfungi tested.
The effect of Tn.B.T.O. on the activity of fungus free enzyme filtrates, containing cellulolytic, amylolytic and pectinolytic enzymes, was investigated enzyme activity was relatively unaffected by up to 200 p.p.m. Tn.B.T.O. Detoxification of Th.B.T.O. and microfungal metabolism in the presence of the biocide were investigated. Modification of optical density of inoculated
Th.B.TI.O. agars was assessed using an apparahxs incorporating a phototransistor. Degree of detoxification was influenced by the availability of differing carbon subs&atds. Metabolism of glucose continued in the presence of Tn.B.T.O.; the preservative appears to be metabolised as sole ca.rbon source and hyphal uptake of tin occurs.
A wide range of microfungi remain viable on impreguated wood and some are capable of detoxifying the kreservative. Estimation of residual organotins in ipregaated stakes indicated fairly rapid breakdown of Tn.B.T.O. to
I).B.T.O. Siguificant uptake of Th.B.T.0. by paint film occurs.
*defined to include temperatures in excess of the normal maximum air temperature recorded in the U.K. during the Summer.