Since antimicrobiol activity and toxicity to higher plants and animals often overlap, it was of interest to test mycotoxins and other fungal products on several microorganisms in order to determine whether antimicrobial activity could be used as a bioassay procedure to detect certain tvnes of mycotoxins.
Materials-The diacetoxyscirpenol, T-2 toxin, roridin A and verrucarin A were purchased from Makor Chemicals, Jerusalem; the patulin and penicillic acid from Aldrich Chemical Co., Milwaukee, Wisconsin; the rubratoxin B and aflatoxins from Calbiochem, La Jolla, California. We wish to thank M. C. Bachman, IMC Chemical Group, Terre Haute, Indiana, for the zearalenone; U. L. Diener, Auburn University, Auburn, Alabama, for the citrinin; T. C. Halsall, University of Oxford, Oxford, England, for the polyporenic acid A; J. M. McGuire, Eli Lilly and Co., Indianapolis, Indiana, for the monensin; and G. B. Whitfield, Upjohn Co., Kalamazoo,Michigan, for the filipin. Assay procedure-Solutions were prepared at a concentration of 1 mg/ml and diluted 10-fold so long as activity was apparent. Paper disks (1/4 inch, Difco Laboratories, Detroit, Michigan) held by tweezers were dipped into the solutions and excess solution removed by touching the disks to the sides of the container. Approximately 20 pJ of solution are retained by the disk'). Disks were placed in triplicate or quadruplicate over the organism-seeded agar surface. Solvent controls were always run.