Briefin vitrostudy onBotrytis cinereaandAspergillus carbonariusregarding growth and ochratoxin A

Abstract

To evaluate the effect of Botrytis cinerea growth on ochratoxin A (OTA) production by Aspergillus carbonarius and degradation. OTA-producing A. carbonarius and B. cinerea were grown on grape-like medium at 20 degrees C for 7 days. Radii of colonies were daily recorded and OTA was analysed. In addition, each B. cinerea isolate was inoculated on grape-like synthetic nutrient medium (SNM) paired with each A. carbonarius isolate at a distance of 45 mm. Botrytis cinerea isolates were also grown in OTA-spiked SNM. Growth rates of B. cinerea and A. carbonarius were 20 and 75 mm day(-1), respectively. The growth of the colonies of each species stopped when they contacted each other in paired cultures. OTA production by A. carbonarius in the contact area was affected by B. cinerea, but no clear trend was observed. All B. cinerea isolates showed to degrade between 24.2% and 267% of OTA from spiked SNM. The ecological advantage of B. cinerea, in terms of growth rate, vs. OTA-producing Aspergillus in some wine-growing regions and its ability to degrade OTA may explain the low levels of this toxin in noble wines. At determinate conditions, the presence of B. cinerea in grapes with A. carbonarius may help in reducing OTA accumulation.