During the course of screening for biologically leading active natural products from fungi, a strain of Aspergillus fumigatus was assessed for antimicrobial activity production. Four parameters consisting of medium culture, pH, temperature and time of fermentation were investigated. The extracts from the fungus cultures displayed different TLC profiles and produced, at least, one inhibition zone in the bioautography assays. Overlapping inhibition zones in the range of Rf 0.09 to 0.65 against Kocuria rhizophila were detected in the bioautography assay of the chloroform extract obtained from Jackson's medium culture, initial pH of 6.0 and incubation at 40ºC for 144 hours. However, the obtained extracts by developing the fungus culture in Vogel's medium furnished the smallest number of active compounds. The obtained chromatographic profiles of the extracts from the fungus cultures by high performance liquid chromatography with photodiode array detector were distinctive, allowing to infer that A. fumigatus secondary metabolites production could be affected by modifying any of the undertaken parameters. It should be pointed out that a remarkable difference among HPLC profiles was observed by using different media culture.
antimicrobial activity; Aspergillus fumigatus; bioautography; fermentation conditions
