COMPARISON OF SUBSTRATES USED TO DETECT TOXINS PRODUCED BY Aspergillus flavus IN SOYBEAN
Keywords:
Aspergillus flavus, Glycine max, soja, substratos, toxinasAbstract
Different substrates were evaluated regarding their capacity for detecting toxins produced by toxic species of Aspergillus flavus. The easy preparation of substrate, its quick reading, contaminations and the possibility of large scale production were also considered. Agar-coconut, agar-coconut with cellophane, agar-water and filter paper were the substrates analyzed. The macroorganism chosen was the toxigenic Aspergillus flavus, isolated from soybean seeds and transferred to Czapeck-agar. The laminae containing fungi were transferred to each substrate. The 24, 48, 72 and 96-hours readings after installation determined the fluorescent intensity produced in long wave ( 365nm) U.V. light while the radial mycelial growth was determined by the colony diameter. The best substrate was agar-coconut which showed medium and high fluorescence intensity after 48-hours incubation, and higher growth in relation to the remaining substrates, mainly the ones with cellophane. The agar-water and filter paper with cellophane substrates were the least efficient obtaining only low intensity fluorescence in approximately 50% of the laminae examined regardless of the incubation period.Downloads
Published
2008-07-28
Issue
Section
Agronomy