Identification and characterization of the biotechnological potential of a wild strain of Paraconiothyrium sp

Metabolomics analysis of mycelial exudates provides insights into fungal antagonists of Armillaria

The genus Armillaria has high edible and medical values, with zones of antagonism often occurring when different species are paired in culture on agar media, while the antagonism-induced metabolic alteration remains unclear. Here, the metabolome of mycelial exudates of two Chinese Armillaria biological species, C and G, co-cultured or cultured separately was analysed to discover the candidate biomarkers and the key metabolic pathways involved in Armillaria antagonists. A total of 2,377 metabolites were identified, mainly organic acids and derivatives, lipids and lipid-like molecules, and organoheterocyclic compounds. There were 248 and 142 differentially expressed metabolites between group C-G and C, C-G, and G, respectively, and fourteen common differentially expressed metabolites including malate, uracil, Leu-Gln-Arg, etc. Metabolic pathways like TCA cycle and pyrimidine metabolism were significantly affected by C-G co-culture. Additionally, 156 new metabolites (largely organic acids and derivatives) including 32 potential antifungal compounds, primarily enriched into biosynthesis of secondary metabolites pathways were identified in C-G co-culture mode. We concluded that malate and uracil could be used as the candidate biomarkers, and TCA cycle and pyrimidine metabolism were the key metabolic pathways involved in Armillaria antagonists. The metabolic changes revealed in this study provide insights into the mechanisms underlying fungal antagonists.

Whole-genome sequencing and functional annotation of pathogenic Paraconiothyrium brasiliense causing human cellulitis

BACKGROUND

A pathogenic filamentous fungus causing eyelid cellulitis was isolated from the secretion from a patient's left eyelid, and a phylogenetic analysis based on the rDNA internal transcribed spacer region (ITS) and single-copy gene families identified the isolated strain as Paraconiothyrium brasiliense. The genus Paraconiothyrium contains the major plant pathogenic fungi, and in our study, P. brasiliense was identified for the first time as causing human infection. To comprehensively analyze the pathogenicity, and proteomics of the isolated strain from a genetic perspective, whole-genome sequencing was performed with the Illumina NovaSeq and Oxford Nanopore Technologies platforms, and a bioinformatics analysis was performed with BLAST against genome sequences in various publicly available databases.

RESULTS

The genome of P. brasiliense GGX 413 is 39.49 Mb in length, with a 51.2% GC content, and encodes 13,057 protein-coding genes and 181 noncoding RNAs. Functional annotation showed that 592 genes encode virulence factors that are involved in human disease, including 61 lethal virulence factors and 30 hypervirulence factors. Fifty-four of these 592 virulence genes are related to carbohydrate-active enzymes, including 46 genes encoding secretory CAZymes, and 119 associated with peptidases, including 70 genes encoding secretory peptidases, and 27 are involved in secondary metabolite synthesis, including four that are associated with terpenoid metabolism.

CONCLUSIONS

This study establishes the genomic resources of P. brasiliense and provides a theoretical basis for future studies of the pathogenic mechanism of its infection of humans, the treatment of the diseases caused, and related research.

The genus Paraconiothyrium: species concepts, biological functions, and secondary metabolites

The genus Paraconiothyrium has worldwide distribution with diverse host habitats and exhibits potential utilisation as biocontrol agent, bioreactor and antibiotic producer. In this review, we firstly comprehensively summarise the current taxonomic status of Paraconiothyrium species, including their category names, morphological features, habitats, and multigene phylogenetic relationships. Some Paraconiothyrium species possess vital biological functions and potential applications in medicine, agriculture, industry, and environmental protection. A total of 147 secondary metabolites have been reported so far from Paraconiothyrium, among which 95 are novel. This paper serves to provide an overview of their diverse structures with chemical classification and biological activities. To date, 27 species of Paraconiothyrium have been documented; however, only seven have been investigated for their secondary metabolites or biological functions. Our review is expected to draw more attention to this genus for providing a taxonomic reference, discovering extensive biological functions, and searching in-depth for new bioactive natural products.