B7 Micromechanic properties
of filamentous fungi
Project B7 (Kwade) focuses on two major topics:
One the one hand adhesion forces between spores of the filamentous
fungus Aspergillus niger are to be measured. On the other hand forces
and tensions which lead to a hyphae breakage are to be determined.
Measurement of the adhesive forces will be realized using an atomic
force microscope which is combined with an inverted light microscope
(figure). By this means information about the morphological development
at the beginning of the cultivation are to be gained. In this connection
the attachment of a spore to the cantilever and to the substrate
is the most challenging task. A simulation of the deagglomeration
of the spores due to fluidic stress will complete this part of the
Measurement of the breakage forces will be carried out using a nanoindenter.
Thus, it is aimed to gain information about the cell wall mechanical
properties. This is an important issue as the cell wall is mainly
responsible for the resistance of the hyphae to breakage. Furthermore,
tensile tests with single hyphae shall be established. The breakage
of hyphae during cultivation due to shear stress shall be simulated.
In this connection the experimentally determined breaking forces
are to be used as an input parameter. Those investigations aim to
predict the morphologic development of the fungus.