Diverse surface properties reveal that substratum roughness affects fungal spore binding

Binding to surfaces by fungal spores is a prerequisite to biofilm formation. The interactions of polytetrafluoroethylene (PTFE), glass, and silicon with three fungal spores, of differing shapes and sizes (Aspergillus niger 1957, Aspergillus niger 1988, and Aureobasidium pullulans), were investigated. A multifractal analysis was conducted to provide quantitative measures of density, dispersion, and clustering of spores on the surfaces. The PTFE, glass, and silicon surfaces presented a range of surface topographies and wettabilities. PTFE was the roughest and most non-wettable surface, whereas silicon was the opposite in terms of both these aspects. The A. niger species were more non-wettable than A. pullulans. Overall, A. niger 1957 attached in higher numbers to PTFE, whereas A. niger 1988 and A. pullulans bound in highest numbers to glass. The results of this work demonstrated that the overall substratum surface roughness influenced spore binding rather than the physicochemical or chemical properties of surfaces or spores.