Biology subjects

Iacovelli, R.

Publications and source records attributed to Iacovelli, R..

4 recordsLinked to original sources

bioRxiv2024

Identification and partial reconstitution of the biosynthetic pathway of bioactive meroterpenoids from Hericium erinaceus (Lion's Mane mushroom).

Hericium erinaceus (Lions Mane mushroom) is widely consumed for its numerous reported benefits for brain health. A growing body of evidence suggests that these benefits are likely attributable to aromatics contained in its fruiting bodies, including the meroterpenoids hericenones. Here, we report the identification and reconstitution of the first two steps of the biosynthetic pathway of hericenones via heterologous expression of the PKS HerA and the carboxylic acid reductase HerB in Aspergillus oryzae. Furthermore, we investigate a putative prenyltransferase that might be responsible for the following biosynthetic step. Ongoing efforts to reconstitute the full pathway will enable large scale production of hericenones and other meroterpenoids in heterologous hosts.

microbiology↗

bioRxiv2024

Discovery and heterologous expression of functional 4-O-dimethylallyl-L-tyrosine synthases from lichen-forming fungi.

Fungal DMATS-type aromatic prenyltransferases are a family of biosynthetic enzymes that catalyze the prenylation of a range of aromatic substrates during the biosynthesis of bioactive indole alkaloids, diketopiperazines, and meroterpenoids. Together with their broad substrate scope and soluble nature, this makes DMATS-type prenyltransferases particularly adept for applications in biocatalysis, for example to derivatize aromatic drug leads and improve their bioactivity. Here, we investigated four putative DMATS-type prenyltransferases from lichen-forming fungi, an underexplored group of organisms that produce more than 1,000 unique metabolites. We were able to successfully express two functional lichen prenyltransferases in the heterologous host A. oryzae, which allowed us to identify them as 4-O-dimethylallyltyrosine synthases. Our extensive bioinformatic analysis shows that related lichen prenyltransferases are likely not active on indoles but rather on aromatic polyketides and phenylpropanoids, common metabolites in these organisms. Overall, our work not only provides new insights into fungal DMATS-type prenyltransferases at the family level, but it also enables future efforts aimed at identifying new candidates for biocatalytic transformations of aromatic compounds.

microbiology↗

bioRxiv2023

Genome sequencing and molecular networking analysis of the wild fungus Anthostomella pinea reveal its ability to produce a diverse range of secondary metabolites

BackgroundFilamentous fungi are prolific producers of bioactive molecules and enzymes with important applications in industry. Yet, the vast majority of fungal species remain undiscovered or uncharacterized. Here we focus our attention to a wild fungal isolate that we identified as Anthostomella pinea. The fungus belongs to a complex polyphyletic genus in the family of Xylariaceae, which is known to comprise endophytic and pathogenic fungi that produce a plethora of interesting secondary metabolites. Despite that, Anthostomella is largely understudied and only two species have been fully sequenced and characterized at a genomic level. ResultsIn this work, we used long-read sequencing to obtain the complete 53.7 Mb genome sequence including the full mitochondrial DNA. We performed extensive structural and functional annotation of coding sequences, including genes encoding enzymes with potential applications in biotechnology. Among others, we found that the genome of A. pinea encodes 91 biosynthetic gene clusters, more than 600 CAZymes, and 164 P450s. Furthermore, untargeted metabolomics and molecular networking analysis of the cultivation extracts revealed a rich secondary metabolism, and in particular an abundance of sesquiterpenoids and sesquiterpene lactones. We also identified the polyketide antibiotic xanthoepocin, to which we attribute the anti-Gram-positive effect of the extracts that we observed in antibacterial plate assays. ConclusionsTaken together, our results provide a first glimpse into the potential of Anthstomella pinea to provide new bioactive molecules and biocatalysts and will facilitate future research into these valuable metabolites.

microbiology↗

bioRxiv2023

Heterologous naringenin production in the filamentous fungus Penicillium rubens

Naringenin is a natural product with several reported bioactivities and is the key intermediate for the entire class of plant flavonoids. The translation of flavonoids into modern medicine as pure compounds is often hampered by their low abundance in nature and difficult chemical synthesis. Here, we investigated new avenues toward producing high levels of naringenin in microbial hosts. Penicillium rubens is a well characterized and highly engineered traditional "workhorse" for the production of {beta}-lactam antibiotics and cholesterol-lowering statins. We explored a secondary metabolite deficient P. rubens strain, P. rubens 4xKO, that was derived from an earlier industrial production strain as a promising microbial host for a recombinant flavonoid pathway. By integrating two plant genes encoding for enzymes in the naringenin biosynthesis pathway into the genome of this strain, we achieved a high naringenin titer in flask fermentations 36 h after feeding the precursor p-coumaric acid. Along with the rapid product accumulation of up to an 88% molar yield, we also observed rapid degradation of naringenin. Based on high-resolution mass spectrometric analysis, we identified the degradation products and proposed a naringenin degradation pathway in P. rubens 4xKO, which is distinct from other flavonoid-converting pathways reported in fungi. Our approach combines fundamental research with application-oriented microbial engineering, and our findings will pave the way to the more sustainable and economically feasible production of flavonoids for pharmaceutical and nutraceutical applications.

biochemistry↗