Modulation of biological activities produced by an endophytic fungus under different culture conditions

The effect of culture conditions on the production of bioactive secondary metabolites by the endophytic fungus Arthrinium state of Apiospora montagnei Sacc. was investigated. Culture broths were partitioned with ethyl acetate and the resulting extracts were evaluated for antibacterial, antifungal, cytotoxic, and antiparasitic activities. The highest levels of activities were arisen from cultures cultivated at 30 ̊C in modified Czapek medium. The best antimicrobial activity against Escherichia coli and Pseudomonas aeruginosa (MIC 90 μg/ml), and against Aspergillus fumigatus (MIC 130 μg/ml) were found in extracts from cultures grown in medium containing 3.1% (w/v) sucrose and 0.1% (w/v) sodium nitrate at pH 4.0 after 9 days of incubation. Cultures grown in medium without modification also showed antiparasitic and antitumoral activities after 9 days at pH 4.0, antifungal activity against Candida albicans at pH 4.0 7.0 (MIC 140 μg/ml), but against A. fumigatus just after 27 days of incubation. A specific bioactive compound may have its production improved if the culture conditions parameters that affect or influence the production were known, which in turn makes the purification process easier.