Effect of water activity on the growth of fungi isolated from "muesli" components

Abstract

The effect of water activity (aw) (0.85-0.97) on the growth of Aspergillus niger, A. flavus, Penicillium chrysogenum, P. brevicompactum and Eurotium herbariorum was examined. The growth of A. niger was lower than that of A. flavus at aw of 0.89 and 0.85. A. niger was the least tolerant of reduced moisture, and low aw (0.85) could prevent colony formation in 5 days. P. brevicompactum was less sensitive to reduced moisture conditions than P. chrysogenum. The maximal growth of E. herbariorum was observed at the level of 0.89 aw. Among the tested fungi, E. herbariorum appeared to be best adapted to the conditions of low aw.