The Potential of Arctic Pseudogymnoascus Fungi in the Biosynthesis of Natural Products

Scarce research into the secondary metabolites of the fungi Pseudogymnoascus spp. has shown a hidden biosynthetic potential for biologically active compounds. This work investigated the biosynthesis of secondary metabolites by two Pseudogymnoascus fungal strains, VKM F-4518 and VKM F-4519, isolated from the surface soil layer of the Kolyma Lowland, Russia, in the Arctic. In these strains, 16-membered trilactone macrolides, (+)-macrosphelides A and B, were identified using 1D and 2D NMR, UHRMS, and optical rotation data. In the fungi of this genus, these metabolites were found for the first time. The studied strains are highly active producers of macrosphelide A, which is being considered as a promising agent for the cure of cancer. Using the antiSMASH secondary metabolite analysis tool, we found that the genome of strain VKM F-4518 contained 32 of the biosynthetic clusters of the secondary metabolite genes (BGC) and that of VKM F-4519 had 17 BGCs. Based on the comparison of the cluster of macrotriolide genes from the fungus Paraphaeosphaeria sporulosa, we found the complete supposed cluster BGCs of macrosphelides in the genomes of two Pseudogymnoascus strains using the BLAST+ program.