Fig. 1

Macromorphological units observed during submerged fed-batch cultivations of A. niger. A Diversity of macromorphologies observed during STR (a) and CELL-tainer cultivations (b–d). Note that pellet formation could be prevented by addition of talcum microparticles to the medium (c). Only condensed regions of the pellets were considered for determination of their width and length (c, d). Scale bar: 100 µm. The pellet size was calculated by measuring the width (B) and the length (C) of more than 100 macromorphological units per cultivation run and calculating the area (D) with the formula A = π width length