Risa Anita, Divinyi Dalma Maja, Baka Erzsébet, Krifaton Csilla
1 Department of Environmental Safety and Ecotoxicology, Faculty of Agricultural and Environmental Sciences, Szent István University , Gödöllő, Hungary.
2 Department of Applied and Environmental Microbiology, Research Institute of Agro-Environmental Sciences, National Agricultural Research and Innovation Centre , Budapest, Hungary.
Acta Microbiol Immunol Hung. 2017 Dec 1;64(4):423-438. doi: 10.1556/030.64.2017.023.
Aflatoxin B1 (AFB1) produced by Aspergillus molds is a genotoxic and carcinogenic mycotoxin. For the elimination of mycotoxins from food and feed, biodetoxification can be a successful tool. The aim of this study was to reveal biodetoxification with the cell-free extracts of Rhodococcus erythropolis NI1 and Rhodococcus rhodochrous NI2, which have been already proved to detoxify AFB1. Extracellular matrices of cultures and also intracellular extracts were applied for detoxification. In both cases, media containing constitutively produced and AFB1-induced enzymes were tested, respectively. The pH tolerance of enzymes in the detoxification was examined at pH 7, 7.5, and 8. The remained genotoxicity was detected by SOS-Chromotest and the AFB1 concentration was measured by high performance liquid chromatography with fluorescence detection. In the extracellular matrix, no reduction of genotoxicity was observed. However, detoxification was completed by intracellular enzymes. In intracellular extracts of both strains, genotoxicity was ceased by the constitutive enzymes within 6 h but induced and constitutive enzymes collectively achieved this result within minutes. Moreover, total biodetoxification was observed at every pH adjustment. Analytical results confirmed >84% degradation potential in each sample. Our results indicate a uniquely fast way for the detoxification of AFB1 with intracellular enzymes of R. erythropolis NI1 and R. rhodochrous NI2.
由曲霉属霉菌产生的黄曲霉毒素B1（AFB1）是一种具有基因毒性和致癌性的霉菌毒素。对于从食品和饲料中消除霉菌毒素，生物解毒可能是一种成功的方法。本研究的目的是揭示用已经被证明可使AFB1解毒的红平红球菌NI1和红串红球菌NI2的无细胞提取物进行生物解毒的情况。培养物的细胞外基质以及细胞内提取物都被用于解毒。在这两种情况下，分别测试了含有组成型产生的酶和AFB1诱导型酶的培养基。在pH值为7、7.5和8时检测了解毒过程中酶的pH耐受性。通过SOS-显色试验检测残留的基因毒性，并用带荧光检测的高效液相色谱法测量AFB1浓度。在细胞外基质中，未观察到基因毒性的降低。然而，细胞内酶完成了解毒。在两种菌株的细胞内提取物中，组成型酶在6小时内使基因毒性消失，但诱导型酶和组成型酶共同作用在几分钟内就达到了这一结果。此外，在每次pH调节时都观察到了完全的生物解毒。分析结果证实每个样品的降解潜力>84%。我们的结果表明，利用红平红球菌NI1和红串红球菌NI2的细胞内酶对AFB1进行解毒是一种独特的快速方法。
