Degradation of ochratoxin A and other mycotoxins by Rhizopus isolates Ja ´nos Varga a, * , Zsanett Pe ´teri a , Katalin Ta ´bori a , Jo ´zsef Te ´ren b , Csaba Va ´gvo ¨lgyi a a Department of Microbiology, Faculty of Sciences, University of Szeged, P.O. Box 533, H-6701 Szeged, Hungary b Animal Health and Food Control Station, P.O. Box 446, H-6701 Szeged, Hungary Received 27 August 2004; received in revised form 4 October 2004; accepted 12 October 2004 Abstract Several filamentous fungi representing the genera Rhizopus and Mucor were examined for their ability to degrade ochratoxin A (OTA), aflatoxin B 1 , zearalenone and patulin in a liquid medium. While none of the isolates exhibited aflatoxin degrading activity, ochratoxin A, zearalenone and patulin were decomposed by several isolates. Ochratoxin A was successfully degraded by Rhizopus stolonifer, R. microsporus , R. homothallicus and two R. oryzae isolates, and by four unidentified Rhizopus isolates. Kinetics of ochratoxin A detoxification of selected Rhizopus isolates was also examined. Rhizopus isolates were able to degrade more than 95% of ochratoxin A within 16 days. A R. stolonifer isolate could also effectively decompose ochratoxin A on moistened wheat. Further studies are in progress to identify the enzymes and genes responsible for ochratoxin detoxification and to transfer these genes to other Rhizopus isolates or microbes which could be used safely for decontamination of cereal products. D 2004 Elsevier B.V. All rights reserved. Keywords: Ochratoxin; Degradation; Rhizopus ; Mycotoxins 1. Introduction Mycotoxins are secondary metabolites of fungi, which may cause diseases in animals or humans. Mycotoxin contamination of agricultural products is a serious health hazard throughout the world. Although the prevention of mycotoxin contamina- tion in the field is the main goal of agricultural and food industries, the contamination of various com- modities with Fusarium, Aspergillus , Alternaria and Penicillium fungi and mycotoxins is unavoidable under certain environmental conditions. Mycotoxin production is dependent on a number of factors, e.g. water activity of the stored product, temper- ature, gas composition, the presence of chemical preservatives and microbial interactions. An inte- grated approach for controlling several of these 0168-1605/$ - see front matter D 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.ijfoodmicro.2004.10.034 * Corresponding author. Tel.: +36 62 544 515; fax: +36 62 544 823. E-mail address: jvarga@bio.u-szeged.hu (J. Varga). International Journal of Food Microbiology 99 (2005) 321 – 328 www.elsevier.com/locate/ijfoodmicro