Inhibitory effect of allyl and benzyl isothiocyanates on ochratoxin a producing fungi in grape and maize. (December 2021)

• Record Type: Journal Article
• Authors: Yang, Bolei; Li, Li; Geng, Hairong; Zhang, Chenxi; Wang, Gang; Yang, Shuo; Gao, Sheng; Zhao, Yueju; Xing, Fuguo
• Is Part Of: Food microbiology. Volume 100(2021)
• Publication Date: 2021-12
• Subjects: Ochratoxin A -- Aspergillus ochraceus -- Aspergillus carbonarius -- Aspergillus niger -- Allyl-isothiocyanate -- Benzyl-isothiocyanate -- Inhibition; Food Microbiology -- Periodicals; Aliments -- Microbiologie -- Périodiques; Food -- Microbiology; Periodicals; Food -- Microbiology -- Periodicals; Food contamination -- Periodicals; 664.001579
• DOI: 10.1016/j.fm.2021.103865
• Languages: English
• ISSNs: 0740-0020

Abstract

Abstract: The purpose of this study was to evaluate the inhibitory effect of allyl-isothiocyanate (AITC) and benzyl-isothiocyanate (BITC) on fungal growth and Ochratoxin A (OTA) production by Aspergillus ochraceus, A. carbonarius and A. niger . Here, we found that spore germination and fungal growth of the three fungi were significantly inhibited when the concentration of AITC and BITC was higher than 1.25 μg/mL. The inhibitory effect of AITC or BITC on A. carbonaceus and A. ochraceus was significantly stronger than that of A. niger. Scanning electron microscopy showed that the mycelia of all three fungi were changed by AITC and BITC. Compared with A. ochraceus and A. carbonarius, the damage to A. niger was lower. For OTA production, AITC and BITC could significantly down-regulated the expression of all five OTA biosynthesis genes in A. niger and A. carbonarius. In A. ochraceus, although several OTA biosynthesis genes were up-regulated, the key PKS gene was down-regulated by AITC and BITC. Twenty-five μg/mL of AITC or BITC could reduce the infection of the three fungi on grapes with inhibition rates of 28%–36% during 14 days and prolong the shelf life of grapes. In maize, the OTA production of the three fungi was significantly reduced by 25 μg/mL of AITC and BITC with the inhibition rates 68.04%–93.49% and 65.87%–75.45%, respectively. These results suggest that AITC and BITC can be used as natural fungicides to prevent A. niger, A. carbonarius and A. ochraceus from infecting grapes and maize and control OTA contamination. Highlights: AITC or BITC could inhibit the growth and spore germination of OTA producing fungi. The mycelia of OTA producing fungi could be changed by AITC and BITC. AITC and BITC could down regulate the expression of OTA biosynthesis genes. The infection of OTA producing fungi on grapes could be inhibited by AITC and BITC. AITC and BITC could significantly reduce the OTA production of fungi.