title: Transcriptional Analysis ofAcinetobactersp.neg1Capable of Degrading Ochratoxin A.
abstract: Ochratoxin A (OTA) is a nephrotoxic and potentially carcinogenic mycotoxin produced by several species ofAspergillusandPenicillium, contaminating grapes, wine and a variety of food products. We recently isolated from OTA contaminated soil vineyard a novel free-living strain ofAcinetobactersp.neg1, ITEM 17016, able to degrade OTA into the non-toxic catabolic product ochratoxin α. Biochemical studies suggested that the degradation reaction proceeds via peptide bond hydrolysis with phenylalanine (Phe) release. In order to identify genes responsible for OTA degradation we performed a differential gene expression analysis of ITEM 17016 grown in the presence or absence of the toxin. Among the differentially expressed genes, six peptidases up-regulated at 6 h were identified. The degrading activity of the carboxypeptidase PJ_1540 was confirmedin vitroin a heterologous system. The enrichment analysis for Gene Ontology terms confirmed that OTA degradation proceeds through peptidase activities and revealed the over-representation of pathways related to Phe catabolism. These results indicate that Phe may represent an energy source for thisAcinetobactersp.neg1strain and that OTA degrading reaction triggers the modulation of further catabolic activities.
authors.affiliation: Institute of Sciences of Food Production, National Research Council Bari, Italy.
authors.forename: Vania C
authors.initials: VC
authors.lastname: Liuzzi
authors.affiliation: Institute of Sciences of Food Production, National Research Council Bari, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Fanelli
authors.affiliation: Institute of Sciences of Food Production, National Research Council Lecce, Italy.
authors.forename: Mariana
authors.initials: M
authors.lastname: Tristezza
authors.affiliation: Institute of Sciences of Food Production, National Research Council Bari, Italy.
authors.forename: Miriam
authors.initials: M
authors.lastname: Haidukowski
authors.affiliation: Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari Bari, Italy.
authors.forename: Ernesto
authors.initials: E
authors.lastname: Picardi
authors.affiliation: Institute of Biomembranes and Bioenergetics, National Research Council Bari, Italy.
authors.forename: Caterina
authors.initials: C
authors.lastname: Manzari
authors.affiliation: Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari Bari, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Lionetti
authors.affiliation: Institute of Sciences of Food Production, National Research Council Lecce, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Grieco
authors.affiliation: Institute of Sciences of Food Production, National Research Council Bari, Italy.
authors.forename: Antonio F
authors.initials: AF
authors.lastname: Logrieco
authors.affiliation: Center Hispano-Luso de Investigaciones Agrarias, University of Salamanca Salamanca, Spain.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Thon
authors.affiliation: Department of Biosciences, Biotechnologies and Biopharmaceutics, University of BariBari, Italy; Institute of Biomembranes and Bioenergetics, National Research CouncilBari, Italy; Consorzio Interuniversitario BiotecnologieTrieste, Italy.
authors.forename: Graziano
authors.initials: G
authors.lastname: Pesole
authors.affiliation: Institute of Sciences of Food Production, National Research Council Bari, Italy.
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Mulè
keywords: food safety; mycotoxin; pathway analysis; peptidase; phenylalanine