Polyamide-6 fibre degradation by a lignolytic fungus

Polyamide-6 was exposed as the sole nitrogen source to the filamentous fungus Phanerochaete chrysosporium under submerged cultivation conditions. Preliminary results are very encouraging. The fungus attached itself to polymer fibres, continued growing, and slowly degraded them. After three months the polymer's molar mass was reduced by 50%, as seen from viscosity measurements. The thermal properties of PA-6 fibres were studied by differential scanning calorimetry, which showed degradation-induced changes of the melting temperatures and enthalpies of fusion indicating a decreasing degree of crystallinity with longer incubation time. Physical degradation was observed by scanning electron microscopy. Degradation was seen as horizontal grooves in the fibres and was continued over a five months period after which the fibres lost most of their physical strength and readily fragmented.