Improving extracellular production of food-use enzymes from Aspergillus nidulans.

Filamentous fungi, and particularly those of the genus Aspergillus, are major producers of enzymatic activities that have important applications in the food and beverage industries. Prior to the availability of transformation systems improvement of industrial production strains was largely restricted to the strategy of mutagenesis, screening and selection. Aspergillus nidulans is a genetically amenable filamentous fungus the ease of handling and analysis of which has led to its use as a model system for the investigation of eukaryotic gene regulation. Although not used industrially it is able to produce a wide variety of extracellular enzymatic activities. As a consequence of half a century of study a considerable resource of characterised mutants has been generated in conjunction with extensive genetic and molecular information on various gene regulatory systems in this micro-organism. Investigation of xylanase gene regulation in A. nidulans as a model for the production of food-use extracellular enzymes suggests strategies by which production of these enzymes in industrially useful species may be improved.