Adaptations in development and secondary metabolism of Aspergillus nidulans isolates from the Erbil province in Iraq.

Abstract

Aspergillus nidulans is a common soil fungus, distributed word wide. Adaptations in development and secondary metabolism of so far uncharacterized isolates from the Erbil province of Iraq were compared to each other and the commonly in laboratory work used strain A4 from Europe was used as a reference. Erb strains showed an increase in conidia formation during asexual development at 37°C when compared to A4. In contrast, fruiting body formation was strongly decreased during sexual development at 30°C or 37°C. The temperature had a strong impact on the synthesis of secondary metabolites. The amount of arugosin A, epi-/shamixanthone and emericellin is increased in A4 compared to the Erb1 isolate during the various tested cultivation conditions. In contrast, the Erb1 isolate produced under these conditions increased amounts of sterigmatocystin. Deviations to the A4 in asperthecin production depends on the growth conditions e.g. changes in the incubation temperature. Increased conidiation of the Erb1 strain correlated with higher levels of austinol and dehydroaustinol production. These two metabolites were also more abundant in the Erb1 isolate during sexual development. Our data suggest that A. nidulans isolates from the Erbil province have adapted developmental and secondary metabolism patterns to local temperature conditions.