PRODUCTION OF FUNGAL VOLATILE ORGANIC-COMPOUNDS IN BEDDING MATERIALS

The high relative humidity of the air and many potential growth media, such as bedding materials, hay and grains in the horse stable, for ex ample, provide suitable conditions for fungal growth. Metabolic activi ty of four common agricultural fungi incubated in peat and wood shavin gs at 25 degrees C and 4 degrees C was characterized in this study usi ng previously specified volatile metabolites of micro-organisms and CO 2 production as indicators. The volatile organic compounds were collec ted into Tenax resin and analysed by gas chromatography. Several micro bial volatile organic compounds (MVOCs), e.g. 1-butanol, 2-hexanone, 2 -heptanone, 3-octanone, 1-octen-3-ol and l-octanol were detected in la boratory experiments; however, these accounted for only 0.08-1.5% of t otal volatile organic compounds (TVOCs). Emission rates of MVOCs were 0.001-0.176 mu g/kg of bedding materials per hour. Despite some limita tions of the analytical method, certain individual MVOCs, 2-hexanone, 2-heptanone and 3-octanone, were also detected in concentrations of le ss than 4.6 mu g/m(3) (0.07-0.31% of TVOC) in a horse stable where pea r and shavings were used as bedding materials. MVOC emission rate was estimated to be 0.2-2.0 mu g/kg x h(-1) from bedding materials in the stable, being about ten times higher than the rates found in the labor atory experiments. Some compounds, e.g. 3-octanone and 1-octen-3-ol, c an be assumed to originate mainly from microbial metabolisms.