Figure 1

Influence of osmolality on Aspergillus niger SKAn1015 productivity. (A) Biomass dry weight (black) and specific productivity (white) after 72 hours of cultivation at 10 different culture broth osmolalities. The corresponding fructofuranosidase bulk activity [U mL^-1] is shown in (B). Values are means for at least three 2L cultivations. Culture broth osmolality was increased permanently with sodium chloride prior to inoculation. To find the optimal osmolality of the process, more cultivations were conducted around proposed optimum at 3 osmol kg^-1. Here, osmolality between treatments was only marginally changed. A paired t-test was conducted to test for statistical differences among treatments. Specific productivity at 3.6 osmol kg^-1 is not significantly different than at 4.2 osmol kg^-1. Bio dry weight at 0.4 osmol kg^-1 is not significantly different than at 1.5 osmol kg^-1. Fructofuranosidase activities at 2.6 and 2.8 osmol kg^-1, 3.1 and 3.2 osmol kg^-1do not differ significantly from each other.