Genome Features and AntiSMASH Analysis of an Endophytic Strain Fusarium sp. R1

Whole genome sequencing of Penicillium and Burkholderia strains antagonistic to the causal agent of kauri dieback disease (Phytophthora agathidicida) reveals biosynthetic gene clusters related to antimicrobial secondary metabolites

Phytophthora agathidicida is a virulent soil pathogen of Aotearoa New Zealand's iconic kauri tree species (Agathis australis (D. Don) Lindl.) and the primary causal agent of kauri dieback disease. To date, only a few control options are available to treat infected kauri that are expressing symptoms of dieback disease. Previous research has identified strains of Penicillium and Burkholderia that inhibited the mycelial growth of P. agathidicida in vitro. However, the mechanisms of inhibition remain unknown. By performing whole genome sequencing, we screened the genomes of four Penicillium and five Burkholderia strains to identify secondary metabolite encoding biosynthetic gene clusters (SM-BGCs) that may be implicated in the production of antimicrobial compounds. We identified various types of SM-BGCs in the genome of each strain, including polyketide synthases (PKSs), non-ribosomal peptide synthetases (NRPSs), and terpenes. Across all four of the Penicillium strains, five SM-BGCs were detected that encoded the biosynthesis of napthopyrone, clavaric acid, pyranonigrin E, dimethyl coprogen and asperlactone. Across all five of the Burkholderia strains, three SM-BGCs were detected that encoded the biosynthesis of ornibactin, pyochelin and pyrrolnitin. Our analysis detected numerous SM-BGCs which could not be characterised. Further efforts should be made to identify the compounds encoded by these SM-BGCs so that we can explore their antimicrobial potential. The potential inhibitory effects of the compounds encoded by the SM-BGCs identified in this study may be worthy of further investigation for their effect on the growth and virulence of P. agathidicida.

Green and efficient extraction of an anticaner agent N-methylsansalvamide using ultrasound-assisted deep eutectic solvents from mycelia of strain Frusarium sp. R1

N-methylsansalvamide (SA), one of cyclic pentadepsipeptides produced by several Fusarium strains, is a promising therapeutic agent for the treatment of cancer disease. In order to make sufficient amount of SA for drug development, a green and efficient extraction process of SA from the mycelia of strain Fusarium sp. R1 using deep eutectic solvent-assisted ultrasound extraction (DES-UAE) was firstly achieved in this work. Solvent screening results indicated that choline chloride-acetic acid (ChCl-Aa) was shown to be the best DES for SA extraction. Through single-factor trials, Plackett-Burman design (PBD) and BoxBehnken design (BBD) experiments, the optimal conditions for DES-UAE with the highest SA yield of 58.2 ± 1.1 mg/g were obtained as follows: ChCl-Aa ratio of 1:2.0 (M/M), water content of 16.4 %, liquid-solid ratio of 37:1 (mL/g), ultrasonic power of 175 W for 47.4 min at 46.3 °C. Compared to conventional extraction approaches, DES-UAE exhibited better SA yield since it caused more serious damage to the surface of mycelia powder on basis of scanning electron microscopy (SEM) analysis. Furthermore, molecular interaction studies suggested that SA has a variety of interactions with ChCl-Aa, including hydrogen and electrovalent bonds as well as van der Waals forces. Finally, the recovery rate of SA reached up to 99.5 % when the ratio of distilled water and DES extracts was 15:1 (V/V). These findings provide the way for large-scale production of SA.

Discovery of Alanomyces manoharacharyi: A Novel Fungus Identified Using Genome Sequencing and Metabolomic Analysis

In this study, a new species of Alanomyces was isolated as an endophyte from the bark of Azadirachta indica from Mulshi, Maharashtra. The identity of this isolate was confirmed based on the asexual morphological characteristics as well as multi-gene phylogeny based on the internal transcribed spacer (ITS) and large subunit (LSU) nuclear ribosomal RNA (rRNA) regions. As this was the second species to be reported in this genus, we sequenced the genome of this species to increase our knowledge about the possible applicability of this genus to various industries. Its genome length was found to be 35.01 Mb, harboring 7870 protein-coding genes as per Augustus and 8101 genes using GeMoMa. Many genes were annotated using the Clusters of Orthologous Groups (COGs) database, the Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO), Swiss-Prot, NCBI non-redundant nucleotide sequences (NTs), and NCBI non-redundant protein sequences (NRs). The number of repeating sequences was predicted using Proteinmask and RepeatMasker; tRNA were detected using tRNAscan and snRNA were predicted using rfam_scan. The genome was also annotated using the Pathogen-Host Interactions Database (PHI-base) and AntiSMASH. To confirm the evolutionary history, average nucleotide identity (ANIb), phylogeny based on orthologous proteins, and single nucleotide polymorphisms (SNPs) were carried out. Metabolic profiling of the methanolic extract of dried biomass and ethyl acetate extract of the filtrate revealed a variety of compounds of great importance in the pharmaceutical and cosmetic industry. The characterization and genomic analysis of the newly discovered species Alanomyces manoharacharyi highlights its potential applicability across multiple industries, particularly in pharmaceuticals and cosmetics due to its diverse secondary metabolites and unique genetic features it possesses.

Annotating Multiple Prebiotic Synthesizing Capabilities Through Whole Genome Sequencing of Fusarium Strain HFK-74

In the present study, seven fungal isolates from effluent treatment plants were screened for the production of prebiotic fructooligosaccharide synthesizing enzymes with the highest activity of fructofuranosidase (17.52 U/mL) and fructosyl transferase (18.92 U/mL) in strain HKF-74. Mining of genome sequence of strain revealed the annotation of genes providing multiple carbohydrate metabolizing capacities, such as amylases (AMY1), beta-galactosidase (BGAL), beta-xylosidase (Xyl), β-fructofuranosidase (ScrB), fructosyltransferase (FTF), and maltose hydrolases (malH). The annotated genes were further supported by β-galactosidase (15.90 U/mL), xylanase (17.91 U/mL), and α-amylase (14.05 U/mL) activities for synthesis of galactooligosaccharides, xylooligosaccarides, and maltooligosaccharides, respectively. In addition to genes encoding prebiotic synthesizing enzymes, four biosynthetic gene clusters (BGCs) including Type I polyketide synthase (PKS), non-ribosomal peptide synthetase (NRPS), NRPS-like, and terpene were also predicted in strain HKF-74. This was significant considering their potential role in pharmaceutical and therapeutic applications as well as in virulence. Accurate taxonomic assignment of strain HKF-74 by in silico genomic comparison indicated its closest identity to type strains Fusarium verticillioides NRRL 20984, and 7600. The average nucleotide identity (ANI) of strain HKF-74 with these strains was 92.5% which was close to the species threshold cut-off value (95-96%) while the DNA-DNA hybridization (DDH) value was 83-84% which was greater than both, species delineating (79-80%), and also sub-species delineating (70%) boundaries. Our findings provide a foundation for further research into the use of Fusarium strains and their prebiotic synthesizing enzymes for the development of novel prebiotic supplements.

Non-ribosomal peptide synthetase (NRPS)-encoding products and their biosynthetic logics in Fusarium

Fungal non-ribosomal peptide synthetase (NRPS)-encoding products play a paramount role in new drug discovery. Fusarium, one of the most common filamentous fungi, is well-known for its biosynthetic potential of NRPS-type compounds with diverse structural motifs and various biological properties. With the continuous improvement and extensive application of bioinformatic tools (e.g., anti-SMASH, NCBI, UniProt), more and more biosynthetic gene clusters (BGCs) of secondary metabolites (SMs) have been identified in Fusarium strains. However, the biosynthetic logics of these SMs have not yet been well investigated till now. With the aim to increase our knowledge of the biosynthetic logics of NPRS-encoding products in Fusarium, this review firstly provides an overview of research advances in elucidating their biosynthetic pathways.

Antimicrobial Action Mechanisms of Natural Compounds Isolated from Endophytic Microorganisms

Infectious diseases are a significant challenge to global healthcare, especially in the face of increasing antibiotic resistance. This urgent issue requires the continuous exploration and development of new antimicrobial drugs. In this regard, the secondary metabolites derived from endophytic microorganisms stand out as promising sources for finding antimicrobials. Endophytic microorganisms, residing within the internal tissues of plants, have demonstrated the capacity to produce diverse bioactive compounds with substantial pharmacological potential. Therefore, numerous new antimicrobial compounds have been isolated from endophytes, particularly from endophytic fungi and actinomycetes. However, only a limited number of these compounds have been subjected to comprehensive studies regarding their mechanisms of action against bacterial cells. Furthermore, the investigation of their effects on antibiotic-resistant bacteria and the identification of biosynthetic gene clusters responsible for synthesizing these secondary metabolites have been conducted for only a subset of these promising compounds. Through a comprehensive analysis of current research findings, this review describes the mechanisms of action of antimicrobial drugs and secondary metabolites isolated from endophytes, antibacterial activities of the natural compounds derived from endophytes against antibiotic-resistant bacteria, and biosynthetic gene clusters of endophytic fungi responsible for the synthesis of bioactive secondary metabolites.

Insights into the genomic architecture of a newly discovered endophytic Fusarium species belonging to the Fusarium concolor complex from India

In this study, a new species Fusarium indicum belonging to the Fusarium concolor species complex is established to accommodate an endophytic fungus isolated from Bambusa sp. and collected from Himachal Pradesh. The identity of this isolate was confirmed based on the asexual morphs, its cultural characteristics, and phylogenetic analyses. This isolate revealed out to be distinct by showing less similarity with described species in the genus Fusarium based on molecular sequence data, approximately 93.9% similarity based on translation elongation factor 1-alpha, and 94.2% similarity based on RNA polymerase II subunit. Furthermore, to increase knowledge about this novel species, whole-genome sequencing was carried out. The results displayed that Fusarium indicum NFCCI 5145 possesses a 40.2 Mb genome and 48.39% of GC content. Approximately 12,963 functional protein-coding genes were carefully predicted and annotated using different BLAST databases, such as Uniprot, Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO), Pathogen Host Interactions (PHI), Clusters of Orthologous Groups (COG), and Carbohydrate-Active enzymes (CAZy). The orthologous proteins were identified using OrthoFinder and used for the phylogenetic analysis. ANIb confirmed that the isolate is closely related to the F. concolor species complex. It is known that Fusarium strains can produce a wide range of bioactive secondary metabolites. Therefore, in-depth mining for biosynthetic gene clusters for secondary metabolite biosynthesis of Fusarium indicum NFCCI 5145 was investigated using Antibiotics and Secondary Metabolites Analysis Shell (AntiSMASH) annotation. AntiSMASH results displayed that this isolate possesses 45 secondary metabolites of biosynthetic gene clusters (BGCs). These findings significantly improved our understanding of the strain Fusarium indicum NFCCI 5145 and its possible applications in different sectors including industry for the secondary metabolites and enzymes it can produce.

Fusarium-Derived Secondary Metabolites with Antimicrobial Effects

Fungal microbes are important in the creation of new drugs, given their unique genetic and metabolic diversity. As one of the most commonly found fungi in nature, Fusarium spp. has been well regarded as a prolific source of secondary metabolites (SMs) with diverse chemical structures and a broad spectrum of biological properties. However, little information is available concerning their derived SMs with antimicrobial effects. By extensive literature search and data analysis, as many as 185 antimicrobial natural products as SMs had been discovered from Fusarium strains by the end of 2022. This review first provides a comprehensive analysis of these substances in terms of various antimicrobial effects, including antibacterial, antifungal, antiviral, and antiparasitic. Future prospects for the efficient discovery of new bioactive SMs from Fusarium strains are also proposed.