Abstract

Fusarium proliferatum has been widely reported as a promising producer of bioactive secondary metabolites. In this study, we conducted genome mining to investigate the putative biosynthetic gene clusters (BGCs) from the fungal strain F. proliferatum ZO-L2-4 isolated from the leaves of Zingiber officinale Roscoe (ginger). First, the fungal gDNA was extracted and then subjected to library preparation. Next, it was sequenced using Illumina NextSeq 2000. The contigs were assembled, then the genes were predicted using AUGUSTUS and GeneMark and annotated using Kyoto Encyclopedia of Genes and Genomes. The BGCs analysis was conducted using Antibiotics and Secondary Metabolites Analysis Shell (AntiSMASH) Fungal Version. From sequencing and assembly, we obtained a genome sequence in a size of 43.6 Mb consisting of 12 nuclear and one mitochondrial contigs, N50 of 4,304,280 bp, L50 of 5, and GC content of 48.14%. Genome annotation suggested that the predicted genes mainly functioned in global maps, followed by carbohydrate metabolism and amino acid metabolism. The AntiSMASH analysis identified 43 BGCs, dominated by terpene biosynthetic genes, nonribosomal peptide synthase (NRPS), NRPS-like, polyketide synthases, and hybrids. Among these, only six BGCs showed the highest homology with the gene clusters that are responsible for the biosynthesis of oxyjavanicin, choline, bikaverin, Alternaria citri toxin (ACT)-toxin II, koraiol, and gibepyrone-A. Most of the remaining were unknown by far. Putative identification employing high-resolution mass spectrometry suggested the presence of beauvericin as the predominant metabolite, along with tryptophol, terpestacin, ergosterol peroxide, indole, and terpendole E in the methanolic extract of F. proliferatum. These findings enhance our understanding of the molecular biology of the Fusarium genus and may pave the way for discovering novel bioactive secondary metabolites from this fungal strain through gene knockout and heterologous expression.

Key words: biosynthetic gene clusters, endophytic fungus, Fusarium proliferatum ZO-L2-4, polyketide synthases, nonribosomal peptide synthase