Figure 3

Effect of osmotic shock on Aspergillus niger SKAn1015 and Aspergillus niger AB1.13 productivity. An osmotic shock was administered to two A. niger SKAn 1015 and two A. niger AB1.13 samples, each with different culture broth osmolality. (A) A. niger SKAn 1015 was cultivated at 0.4 and 2.8 osmol kg^-1. The 0.4 osmol kg^-1 sample was osmotically shocked to 2.8 and additionally to 4.5 osmol kg^-1. The osmolality of the other sample was elevated from 2.8 to 4.5 osmol kg^-1. (B) A. niger AB1.13 was grown at 0.2 and 1.3 osmol kg^-1. The 0.2 and 1.3 osmol kg^-1 samples where both shocked to an osmolality of 2.5 osmol kg^-1. All samples were incubated for one hour in shaking flasks at 37°C/30°C, 120 min^-1. All experiments were done in triplicate. Black bars show enzyme activity after one hour incubation without osmotic shock, white and grey bars represent samples after one hour incubation in which osmolality was increased. In both cases only an osmotic shock administered to standard culture broth osmolality showed a significant elevation in enzyme activity.