Fungal biodeterioration of copper metal

In this work, geoactive fungi including Aspergillus niger, Beauveria caledonica and Paecilomyces javanicus, were used to investigate their biocorrosion and deteriorative effects on copper metal to gain an understanding of the roles that fungi may play in biodeterioration of such a material in the built environment. It was clearly demonstrated that the test fungi possessed a high tolerance to copper metal. New biominerals resulted from fungal interactions with copper metal mainly arising from organic acid excretion. Copper oxalate was formed by oxalate excretion from the fungi and different patterns of bioweathering and biomineralization were generated on the copper surfaces. In addition, copper could be dissolved by certain fungi, result in significant biodeterortive effects such as etching and pitting. These results provide compelling evidence for deteriortion of copper metal by fungi and that organic acids, particularly oxalate, play an important role in this process. Such properties of metal biocorrosion and deterioration indicate the potential significance of fungi in biodeterioration of metal substrates and the importance of considering methods of protection and preservation in the built environment.