NON-PRODUCTIVITY OF AFLATOXIN BY JAPANESE INDUSTRIAL STRAINS OF ASPERGILLUS

Abstract

When the Japanese industrial strains of Aspergillus were cultured on rice, they produced various kinds of fluorescent substance, most of which weresimilar, in excitation and emission maxima and in thin-layer chromatograms, to those produced in the shaking culture reported in Part I.The aflatoxin productivity of 13 strains selected was further examined critically by culturing them on larger scales using two liters of the ADYE and MATELES' medium (stationary culture) and/or one kg of polished rice, and by measuring the UV absorption spectrum of the spots separated by thin-layer chromatography. The results showed that the fluorescent spots produced by these strains were classified into nine patterns, and that none showed the same absorption spectrum as that of aflatoxin.However, there still remains a question whether or not these fungi produce a trace amount of aflatoxin, which is rather difficult to prove by these cultivation methods. Since the presence of even a trace of aflatoxin in food should be avoided, it is desirable to find a correlation which may exist between the aflatoxin productivity of an organism and its mycological characters, by which the detection of aflatoxin-producing organism becomes easier and more accurate.