Secondary Metabolism Variation of a Marine Fungus Following Treatment with Dielectric Barrier Discharge Plasma and Chemical Mutagens

摘要

To activate cryptic secondary metabolic genes is a crucial issue in the search for new natural products from microorganisms. For this purpose, in the present study, a marine fungal strain Penicillium chrysogenum WP-1 was treated with dielectric barrier discharge plasma, chemical mutagens, and their combination. Seven mutants with higher antibacterial activities were chosen among the colonies that survived the different treatments. As revealed by high resolution LC-MS analysis, their secondary metabolic fingerprints displayed significant variations in the numbers of total distinguishable peaks (metabolites), newly generated metabolites, nitrogenated compounds, compounds with skeletons larger than C_(20), compounds with molecular weights greater than 400 Da, and in the yields of the original metabolites. Additionally, different mutagenesis treatments resulted in different metabolite profiles. Moreover, most of these mutants showed morphological variations compared with the original strain. This study reveals that the plasma and plasma-chemical mutagen combination are effective methods to activate silent fungal secondary metabolites. It lays the foundation for the application of plasma mutagenesis in marine fungal natural product research.