Abstract

Muqtada Al-Maliki, Zainab Aziz Qausim and Saddam Hisham Saatchi

Arid soils are complex ecosystem that maintains topographically distinct mycoflora populations. A total of 45
soil samples collected from the arid soils in Iraqi desert were cultured by dilution plate method and screened
for Aspergillus terreus. The aim of this study was to enhance ecological knowledge of cultured colonies
variation of A. terreus as well as environmental interactions in arid soils. An attempt is made to
comprehensively screen desert soil for the wild type A. terreus producing lovastatin. The results show that
the most frequent Aspergillus spp. included: A. niger (159 isolates), A. terreus (143), A. flavus (115) and A.
fumigates (42) and other fungi. Genetically, the diagnoses of 19 isolates of A. terreus were in the scope of our
interest. The specific primer pair had monomorphic bands of approxi mately PCR product of 450 bp.
Ribotyping isolates of A. terreus with primer pairs (ITS1/ITS4 and ITS1/ITS2) were 19 isolates, with a single
PCR product of 550-600 bp and 280-380 bp, respectively. RAPD-PCR was also used to distinguish between
ecological patterns generated and allowed a distinction of very closely related environmental isolates.
Lovastatin production was carried out with thin layer chromatography. Results suggest that phenotypic
variations in A. terreus isolates were not useful for identifying them, and showed no significance in the
identification in all the sites studied. However, using discriminatory molecular methods, such as
amplification of the targeted regions by specific and universal characterization of the isolates could be
pivotal in understanding ecological variation. Wild type soil isolates of A. terreus have the ability to produce
lovastatin.