title: Ochratoxigenic black species of Aspergilli in grape fruits of northern Italy identified by an improved PCR-RFLP procedure.
abstract: A collection of 356 isolates of Aspergillus spp. collected during 2006 and 2007 from grapevines in northern Italy were identified through Internal Transcribed Spacer based Restriction Fragment Length Polymorphism (ITS-RFLP) and tested for ochratoxin A (OTA) production. Restriction endonuclease digestion of the ITS products using the endonucleases HhaI, HinfI and RsaI, distinguished five different RFLPs. From each pattern, three samples were sequenced and the nucleotide sequences showed different species corresponding to Aspergillus niger, A. carbonarius, A. tubingensis, A. japonicus and A. aculeatus. By comparing the sequences of the ITS regions, also the uniseriate species A. japonicus and A. aculeatus could be differentiated by HinfI digestion of the ITS products. Among the aspergilli, A. niger was the major species associated with grapes during 2006 (57.4%), while A. carbonarius was the major species during 2007 (46.6%). All the strains of Aspergillus were tested for their ability to produce OTA on Yeast extract sucrose medium (YES), as it was tested as an optimal substrate for the evaluation of OTA production by black aspergilli. Out of 356 isolates, 63 (17.7%) isolates produced OTA ranging from 0.05 to 3.0 µg mL(-1). Most of the ochratoxigenic isolates were A. carbonarius (46) in both years, but also some strains of A. tubingensis (11) and A. japonicus (6) produced lower amounts of OTA.
authors.affiliation: Centre of Competence for the Innovation in the Agro-environmental Sector, Università degli Studi di Torino, Via L. da Vinci 44, Grugliasco (TO) I-10095, Italy. davide.spadaro@unito.it
authors.forename: Davide
authors.initials: D
authors.lastname: Spadaro
authors.forename: Subban
authors.initials: S
authors.lastname: Patharajan
authors.forename: Alessia
authors.initials: A
authors.lastname: Lorè
authors.forename: Angelo
authors.initials: A
authors.lastname: Garibaldi
authors.forename: Maria Lodovica
authors.initials: ML
authors.lastname: Gullino
mesh_terms: D001234:Aspergillus niger / Q000302:isolation & purification* / Q000378:metabolism; D016172:DNA Fingerprinting; D004262:DNA Restriction Enzymes; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology / Q000379:methods*; D009793:Ochratoxins / Q000302:isolation & purification* / Q000378:metabolism; D016133:Polymerase Chain Reaction / Q000379:methods*; D012150:Polymorphism, Restriction Fragment Length; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D027843:Vitis / Q000737:chemistry / Q000382:microbiology*
chemical_list: D009793:Ochratoxins; C025589:ochratoxin A; D004262:DNA Restriction Enzymes