The genus Aspergillus has a worldwide distribution and is one of the
most common of all groups of fungi. They are possibly the greatest
contami- nants of natural and man-made organic products, and a few
species can cause infections in man and animals. The aspergilli are also
one of the most important mycotoxin-producing groups of fungi when
growing as contaminants of cereals, oil seeds, and other foods. Not all
aspergilli are viewed as troublesome contaminants, however, as several
species have had their metabolic capabilities harnessed for commercial
use. The aspergilli have long been associated in the Far East with the
koji stage of several food fermentations, particularly soy sauce and
miso, and subsequently as a source of useful enzymes. The ability of
these fungi to produce several organic acids, especially citric acid,
has created major industrial complexes worldwide. Traditional methods of
strain develop- ment have been extensively studied with the industrial
strains, while more recently, recombinant DNA technology has been
applied to the aspergilli with emphasis on heterologous protein
production. In compiling this book, I have been fortunate to have the
full enthu- siastic involvement of the authors, and to them I extend my
very grateful thanks for mostly being on time and for producing such
readable and authoritative chapters. Collectively, we hope that our
efforts will strengthen the scientific understanding of this intriguing
group of filamentous fungi and further their use in the field of
biotechnology.