included in the bioassay tests that employed artificial
mixtures of M. albus compounds. Another 11 compounds,
including several positional isomers, were tentatively
identified based on the best fit of their mass spectra when
compared to the NIST database. These were not included in
the bioassay tests.
As a first approximation, the quantitative analysis of each
compound found in fungal cultures was based on its relative
peak area obtained after GC-MS analysis. This number was
used to prepare artificial atmospheres of the M. albus gases
in the relative proportions that they occur in 12 days old
fungal cultures. A mixture of the positively identified
compounds was placed in a small plastic cup located in the
center of a Petri plate containing PDA. Small pieces of
agar 3 mm3 containing a freshly grown fungal culture were
also placed on the agar plate. The headspace of the Petri
plate was 50 ml and this was used to calculate the
concentration of VOC’s per ml when assessing the IC
50’s of each compound. All bacteria and yeasts were
individually streaked on the PDA test plates and the only
viability of these organisms was determined