Two hundred and fourteen strains of the
Aspergillus were cultured both in agar slants and in a liquid medium by shaking, and the productivity
of aflatoxins was studied, respectively, by observation of the fluorescence of the medium and by fluorometry and thin-layer chromatography, using the aflatoxin-producing strain ATCC 15517 as a control.
In the slant culture of Czapek agar, only a few strains showed the stronger blue or green fluorescence than that of the control strain. Statistically, in the yellow-green-spored
Aspergillus, certain mycological characters were seemed to be closely associated with the productivity of fluorescence.
When the chloroform solutions of the yellow-green-spored
Aspergillus, prepared from the shake-cultured broth by the same preparation method as that of aflatoxin, were analyzed fluorometrically, none was found to have the same excitation wavelength as that of control in the blue fluorescence; on the contrary, in the green fluorescence, the majority of strains showed both the same excitation wavelength and emission wavelength as those of control.
On thin-layer chromatograms, there were spots corresponding to aflatoxins, but they were quite different from aflatoxins as will be reported in Part 2.
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