Atomic Force Microscopy Applied to the Study of Whatman Paper Surface Deteriorated by a Cellulolytic Filamentous Fungus

In this study AFM technique has been used to observe the degradation of cellulose fibres in paper samples used as substrata for the growth of a filamentous fungus known to be responsible for damage to art works made from or supported on paper. Images obtained from the analysis of artificially deteriorated samples have been used for comparison with topographies obtained by AFM from naturally affected samples. As ‘‘control’’ images, AFM topographies of samples obtained from the same paper quality utilised as substrata for fungal inoculum were considered. The samples that were artificially deteriorated and those naturally affected by biological agents showed, at the molecular level, distinct surface differences when compared with control images. The biodegradation of cellulose fibres that appeared in AFM images can be attributed to the activity of both cellulolytic enzymes and acidic compounds produced by the fungal cells. Further studies using the AFM technique could reveal interesting aspects of paper biodeterioration caused by different microrganisms and might allow for a better description of the different stages of fungal attacks on cellulose fibres.