Biodegradation of Ochratoxin A by Bacterial Strains Isolated from Vineyard Soils

Toxins

Palmira De Bellis¹  Mariana Tristezza²  Miriam Haidukowski¹  Francesca Fanelli¹  Angelo Sisto¹  Giuseppina Mulè¹  Francesco Grieco² 

[1] Institute of Sciences of Food Production, National Research Council, Unit of Bari, via Amendola 122/O, Bari 70126, Italy;Institute of Sciences of Food Production, National Research Council, Unit of Lecce, via Provinciale Lecce-Monteroni, Lecce 73100, Italy;

关键词: ochratoxin;    biodegradation;    soil bacteria;    detoxification;    Acinetobacter;   

DOI  :  10.3390/toxins7124864

来源: mdpi

【 摘 要 】

Ochratoxin A (OTA) is a mycotoxin with a main nephrotoxic activity contaminating several foodstuffs. In the present report, five soil samples collected from OTA-contaminated vineyards were screened to isolate microorganisms able to biodegrade OTA. When cultivated in OTA-supplemented medium, OTA was converted in OTα by 225 bacterial isolates. To reveal clonal relationships between isolates, molecular typing by using an automated rep-PCR system was carried out, thus showing the presence of 27 different strains (rep-PCR profiles). The 16S-rRNA gene sequence analysis of an isolate representative of each rep-PCR profiles indicated that they belonged to five bacterial genera, namely Pseudomonas, Leclercia, Pantoea, Enterobacter, and Acinetobacter. However, further evaluation of OTA-degrading activity by the 27 strains revealed that only Acinetobacter calcoaceticus strain 396.1 and Acinetobacter sp. strain neg1, consistently conserved the above property; their further characterization showed that they were able to convert 82% and 91% OTA into OTα in six days at 24 °C, respectively. The presence of OTα, as the unique OTA-degradation product was confirmed by LC-HRMS. This is the first report on OTA biodegradation by bacterial strains isolated from agricultural soils and carried out under aerobic conditions and moderate temperatures. These microorganisms might be used to detoxify OTA-contaminated feed and could be a new source of gene(s) for the development of a novel enzymatic detoxification system.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.