Demonstrating presence of siderophore in some fungi

The aim of this study, was to demonstate the presence of siderophores in Candida and Aspergillus strains, by using several mediums and molecular methods. For demonstrating siderophores by using mediums, we used three mediums; CASAD medium, CAS/ MEA medium and O-CAS medium, respectively. We couldn't recognize any CAS reaction in CAS/ MEA medium, in which we realised %33.3 percentage positive results in CASAD medium. We obtained % 75 percentage positive results in O-CAS medium. So in comparison with other two mediums, O-CAS medium was more simple, more sensitive, economic and more successful. Demonstrating presence of siderophores by molecular methods, was the second step of this study. We verified this step by using Real-Time PCR- SYBR Green method, which is more economic and gives results in shorter time then TaqMan® Probe. We operated this step by CaSIT1 primers ( forward and reverse), with fourteen samples (Candida and Aspergillus strains). Results obtained from nonnuclear methods and Real-Time PCR SYBR Green method was similar. By this method, we obtained positive results in twelve (% 87.5) of fourteen samples. As we used CaSIT1 primers (forward and reverse) C. tropicalis and A. niger was used as negative control strains. According to the results of this study, we defined some standard values (St. 1.03 E1< St. 1.14 E1< St. 1.28 E1< St. 1.52 E1< St. 1.85 E1< St. 4.59 E1) and obtained a standard curve. Due to this standard curve we defined, sidA gene expression amounts of the other samples.Key word: Candida, Aspergillus, siderophore.