かび毒の細胞に対する毒性評価と産生菌検出に関する研究

Abstract

In addressing the problem of mycotoxin toxicity and contamination risk, we conducted following studies encompassing toxicity evaluation and detection techniques.Toxicity evaluation of mycotoxins involved an exploration of the effects of aflatoxin B 1 (AFB 1 ), patulin (PAT), and deoxynivalenol (DON) exposures, as well as their derivatives and glycosides, using DNA microarray analysis in a yeast cell system. AFB 1 induced gene expression changes related to the sphingolipid metabolic pathway, resulting in cell cycle abnormalities. As for the comparison among type-B trichothecene mycotoxins, 15-acetyl-DON (15AcDON), fusarenon X (FusX), and DON exhibited higher toxicity. The assessment of PAT toxicity also considered the effect of ascorbic acid (AsA), revealing a recovery of cell proliferation and normalization of gene expression upon AsA addition. In addition to yeast cell testing, toxicity evaluation using green algae highlighted distinct toxicities between 15AcDON and FusX under specific light irradiation conditions.Exploring the regulation of AF synthesis through light irradiation tests revealed that blue-green light at 500-525 nm maximized AF synthesis, whereas a wavelength that completely inhibited AF synthesis was not identified in the visible light range of 400-720 nm. The development of a simple detection medium for AF-synthetic fungi involved the incorporation of AF by alfa-cyclodextrin and the addition of activated carbon (AC). The inclusion of AC not only reduced scattering light around a colony on the culture plate but also thought to be provided the necessary metal ions for improved observation efficiency.