Determination of destruxins, cyclic peptide toxins, produced by different strains of Metarhizium anisopliae and their mutants induced by ethyl methane sulfonate and ultraviolet using HPLC method

Metarhizium anisopliae produces a family of cyclic peptide toxins, destruxins (DTXs), which exhibit various insecticidal activity. Four major DTXs have been separated by HPLC and identified by the liquid chromatography electrospray mass spectrometry (LC-ESI-MS) methods. Strain F061 of M. anisopliae produced large amounts of (DTXs), especially DTX-A (12.84±0.04 μg/ml), DTX-B (66.89±2.57 μg/ml) and DMDB (1.41±0.13 μg/ml). High levels of DTX-E (4.19±0.13 μg/ml) were produced by strain F007 of M. anisopliae. The results of our studies also showed that either ethyl methane sulfonate (EMS) or ultraviolet (UV) can significantly increase the production of DTXs. Mutant 61E-9 produced high levels of DTX-A (30.05±1.97 μg/ml), DTX-B (110.37±10.02 μg/ml) and DMDB (8.30±0.45 μg/ml). High levels of DTX-E (20.59±2.65 μg/ml) were produced by mutant 7E-3. Both mutant strains are suitable for industrial fermentation processes and possess a wide range of potential applications in the area of metabolic toxin production.