A number of fungi, including Aspergillus nidulans, produce
dark-brown pigments known as melanins, which are present in
cell walls associated with chitin and/or in the medium as
soluble extracellular polymers (Bull 1970; Ellis and Griffiths
1974). This pigment appears to be essential for protection of
the organisms against environmental stress. In vitro studies
have shown that melanized fungi are more resistant than those
no-melanized to UV light-induced and oxidant-mediated
damages, temperature extremes, hydrolytic enzymes, heavy
metal toxicity and antimicrobial drugs