This invention relates to newly identified auxotrophs, polynucleotides, polypeptides encoded by such polynucleotides, the use of such polynucleotides and polypeptides, as well as the production and isolation of such polynucleotides and polypeptides. More particularly, the polynucleotides and polypeptides of the present invention have been putatively identified as being very important to the growth and/or reproduction of Aspergillus fumigatus.