In vitro correlation among growth and Ochratoxin A accumulation in relation to Day/night fluctuations for Aspergillus carbonarius cultured on grape

DAIANA GARCIA; ACHILLE VINCENZO; MARIN, SONIA; PANZARINI GIUSEPPE; GALLO ANTONIA; SOLFRIZZO MICHELLE; PERRONE GIANCARLO

Martina Franca

Congreso; Final MycoRed Conference 2013; 2013

Many factors influence mould growth and mycotoxin accumulation such as temperature, substrate aeration, water activity (aw), photoperiod, inoculum concentration, etc. Previous studies have evidenced the importance of temperature and day/night fluctuations on growth and ochratoxin A (OTA) production by Aspergillus carbonarius in synthetic media. The aim of the present work is to study the effect of different temperatures and photoperiod on correlation among A. carbonarius growth and OTA production on homogenized grape berries, and to assess the possible use of a predictive model for OTA. Two ochratoxigenic isolates of A. carbonarius isolated from grape were used in this research. Red grape berries were sterilized, homogenized, poured into Petri dishes and used as growth medium. A sterile cellophane disk was placed on the surface of the grape medium prior to fungal inoculation to allow for determination of biomass dry weight, diameter and area of fungal colony and OTA concentration. The three variables were measured along time for a 10-day period. Different sets of inoculated plates were incubated at a) 20°C in the dark, b) 28°C in the light and c) alternance of light/dark and temperature 28/20°C (14 h light/28°C and 10 h dark/20°C). Significant differences (p