Biology subjects

Frisvad, J. C.

Publications and source records attributed to Frisvad, J. C..

3 recordsLinked to original sources

bioRxiv2025

Penicillium hordei acidification precipitates Bacillus subtilis lipopeptides to evade inhibition

Interkingdom interactions are crucial for community and ecosystem functioning, however secondary metabolites mediating interactions between plant beneficial bacteria and fungi remain understudied. Penicillium and Bacillus species can individually suppress soilborne phytopathogens and promote plant growth. Here, we showed that Penicillium hordei and Bacillus subtilis co-culture led to precipitation of B. subtilis lipopeptides, observed as white line in agar. Metabolomic analysis revealed B. subtilis triggered enhanced production of fungal terrestric acid and its biosynthetic intermediates, which induced lipopeptide precipitation to prevent P. hordei inhibition by chemical inactivation and physical barrier formation. Besides lipopeptide precipitation, terrestric acid-mediated acidification progressively reduced production of antifungal plipastatins. The lack of lipopeptide production permitted P. hordei to invade and overgrow B. subtilis colony. We demonstrated that the white line phenomenon was conserved among closely related fungi via secretion of terrestric, fulvic or barceloneic acids. Furthermore, terrestric acid at specific concentrations acted as a universal metabolite that drives B. subtilis lipopeptide precipitation even in distantly related fungi. This study provides new insights into acidification as a fungal defensive strategy that may promote co-existence with beneficial bacteria exhibiting strong antagonistic potential, thereby contributing to the formation of a stable rhizosphere community.

microbiology↗

bioRxiv2024

Different metabolite profiles across Penicillium roqueforti populations associated with ecological niche specialisation and domestication

Fungi are known to produce many chemically diversified metabolites, yet their ecological roles are not always fully understood. The blue cheese making fungus Penicillium roqueforti thrives in different ecological niches and is known to produce a wide range of metabolites, including mycotoxins. Three P. roqueforti populations have been domesticated for cheese production and two populations thrive in other anthropized environments, i.e., spoiled food, lumber and silage. Here, we looked for differences in targeted and untargeted metabolite production profiles between populations using HPLC-HR-Q-TOF and UHPLC-Q-TOF-HR-MS/MS. The non-cheese populations produced several fatty acids and different terpenoids, lacking in cheese strains. The Termignon cheese population displayed intermediate metabolite profiles between cheese and non-cheese populations, as previously shown for other traits. The non-Roquefort population, the cheese population with the strongest domestication syndrome, produced the lowest quantities of measured metabolites, including known mycotoxins such as mycophenolic acid (MPA), andrastin A and PR toxin. Its inability to produce MPA was due to a deletion in the mpaC gene, while a premature stop codon in ORF 11 of the PR toxin gene cluster explained its absence and the accumulation of its eremofortin A & B intermediates. In the Roquefort population, we detected no PR toxin nor eremofortins A or B, but found no indel or frameshift mutation, suggesting downregulation. Our results suggest that domesticated cheese populations were selected for lower toxin production while populations from other anthropized environments maintained high metabolite diversity, the bioactivities of these compounds being likely important in these ecological niches.

microbiology↗

bioRxiv2023

Unveiling the Microbial Diversity and Associated Secondary Metabolism on Black Apples

Black apples are the late-stage microbial decomposition of apples after having fallen to the ground. This phenomenon is highly comparable from year to year, with the filamentous fungus Monilinia fructigena most commonly being the first invader, followed by Penicillium expansum. Motivated by the fact that only little chemistry has been reported from apple microbiomes, we set out to investigate the chemical diversity and potential ecological roles of secondary metabolites (SMs) in a total of 38 black apples. Metabolomics analyses were conducted on either whole apples or small excisions of fungal biomass derived from black apples. Annotation of fungal SMs in black apple extracts was aided by cultivation of 15 recently isolated fungal strains on 9 different substrates in an OSMAC approach, leading to identification of 3319 unique chemical features. Only 6.8% were attributable to known compounds based on analysis of HPLC-HRMS/MS data using spectral library matching tools. Of the 1606 features detected in the black apple extracts, 32% could be assigned as fungal-derived, due to their presence in the OSMAC-based training dataset. Notably, the detection of several antifungal compounds clearly indicates the importance of such compounds for invasion of and control of other microbial competitors on apples. In conclusion, the diversity and abundance of microbial SMs on black apples was found to be much higher than that typically observed for other environmental microbiomes. Detection of SMs known to be produced by the six fungal species tested also highlights a succession of fungal growth following the initial invader M. fructigena. ImportanceMicrobial secondary metabolites constitute a significant reservoir of biologically potent and clinically valuable chemical scaffolds. However, their usefulness is hampered by rapidly developing resistance, resulting in reduced profitability of such research endeavours. Hence, it is vital that the ecological role of such microbial secondary metabolites be considered to understand how best to utilise such compounds as chemotherapeutics. Here, we explore an under-investigated environmental microbiome in the case of black apples; a veritable "low-hanging fruit", with relatively high abundances and diversity of microbially produced secondary metabolites. Using both a targeted and untargeted metabolomics approach, the interplay between metabolites, other microbes and the apple host itself was investigated. This study highlights the surprisingly low incidence of known secondary metabolites in such a system, highlighting the need to study the functionality of secondary metabolites in microbial interactions and complex microbiomes.

ecology↗