Influence of water activity and temperature on growth of isolates of Aspergillus section Nigri obtained from grapes

The effects of water activity (a(w)) and temperature on growth of Aspergillus section Nigri isolated from wine grapes were investigated on an agar medium with composition similar to that of grapes. Temperatures in the range of 10-37 degreesC were tested. Optimum temperatures for growth were between 30 and 37 degreesC. Water activity levels ranging from 0.90 to 0.995 were tested. Optimum a(w) for growth was 0.98 in most cases. Statistical differences were found among the groups tested (A. carbonarius, A. niger aggregate and A. section Nigri uniseriates). Growth rates models for the factors assayed have been obtained. (C) 2004 Elsevier B.V. All rights reserved.