Abstract (eng)
Within the framework of this diploma thesis different methods for surface sterilization and isolation of fungal endophytes from rhizomes of Alpinia malaccensis and roots of Curcuma sp. (Zingiberaceae) were tested. Five endophytes were isolated and characterized through DNA-sequencing. Their dichloromethane extracts were phytochemically characterized by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) and compared with the profiles of the plant extracts. Profiles of extracts of endophytes proved to be completely different. Physiological tests showed a growth optimum of 22°C for all isolates except Neosartorya fischeri, which preferred higher temperatures of 37°C. Furthermore the effect of plant extracts of Alpinia malaccensis and Curcuma sp. on the growth speed of the fungi were analyzed. The Alpinia-medium lead to a more increased growth speed of Penicillium commune (EP2) than the Curcuma-medium and the extract-free control-medium. By contrast, growth of the endophyte Penicillium purpurogenum (EPC) isolated from Curcuma sp. was completely inhibited. Thin layer bioautography with spores from Cladosporium sphaerospermum showed moderate antifungal activity for all isolates except for Neosartorya fischeri (EP3). Similar results were obtained with feeding experiments on Spodoptera-larvae, where all isolates except of Neosartorya fischeri (EP3) showed a more or less existent mortality rate. Competition tests between endophytes and against Cladosporium sphaerospermum showed increased competitiveness of Penicillium commune (EP1), Penicillium commune (EP2) und Neosartorya fischeri (EP3), opposite to Cladosporium sphaerospermum and Penicillium purpurogenum (EPC).