The filamentous fungi are perhaps unique in the diversity of their metabolic activities. This includes biosynthetic as well as degradative activities, many is to provide an of which are of industrial interest. The objective of this text up-to-date and broad review which emphasizes the genetic and molecular biological contribution in the field of fungal biotechnology. This text begins with an overview of the tools and methodologies involved which, to a large extent, have been developed in the model filamentous fungus Aspergillus nidulans and subsequently have been extended to commercially...