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Woody biomass represents an important source of carbon on earth, and its global recycling is highly dependent on Agaricomycetes fungi. White-rot Basidiomycetes are a very important group in this regard, as they possess a large and diverse enzymatic repertoire for biomass decomposition. Among these enzymes, the recently discovered lytic polysaccharide monooxygenases (LPMOs) have revolutionized biomass processing with their novel oxidative mechanism of action. The strikingly high representation of LPMOs in fungal genomes raises the question of their functional versatility. In this work, we studied an AA9 LPMO from the white-rot basidiomycete Pycnoporus sanguineus, PsAA9A. Successfully produced as a recombinant secreted protein in Pichia pastoris, PsAA9A was found to be a C1-specific LPMO active on cellulosic substrates, generating native and oxidized cello-oligosaccharides in the presence of an external electron donor. PsAA9A boosted cellulolytic activity of glysoside hydrolases from families GH1, GH5, and GH6.This study serves as a starting point towards understanding the functional versatility and biotechnological potential of this enzymatic family, highly represented in wood decay fungi, in Pycnoporus genus. Key points: • PsAA9A is the first AA9 from P. sanguineus to be characterized. • PsAA9A has activity on cellulose, producing C1-oxidized cello-oligosaccharides. • Boosting activity with GH1, GH5, and GH6 was proven. [ABSTRACT FROM AUTHOR]

The effects of Cu on the activity and expression of laccase were investigated in seven different strains of Pycnoporus coccineus collected from different regions in Korea. Cu was toxic to mycelial growth at concentrations greater than 0.5 mM CuSO and showed complete growth inhibition at 1 mM in the liquid culture. However, Cu significantly upregulated the extracellular laccase activity at 0.2 mM in five strains of P. coccineus, IUM4209, IUM0032, IUM0450, IUM0470, and IUM4093, whereas two strains, IUM0253 and IUM0049, did not respond to Cu, despite being closely related to the other five strains. Subsequent RT-PCR analysis also showed that the laccase mRNA was highly expressed only in the former five strains in the presence of Cu. Taken together, these results indicate that Cu regulates expression of the laccase gene in a strain-dependent manner. The five strains commonly produced a single predominant laccase protein with a molecular weight of 68 kDa. Peptide sequencing revealed that the laccase was a homolog of Lcc1 of P. coccineus, which was isolated in China. The Cu-induced culture supernatants exhibited high degradation of polycyclic aromatic hydrocarbons, indicating that the 68-kDa laccase is the primary extracellular degradative enzyme in P. coccineus. [ABSTRACT FROM AUTHOR]

A phylogenetic analysis of Trametes and related taxa is proposed, based on a wide sampling of temperate and tropical species. Concatenate sequences of ribosomal DNA (ITS1-5.8S-ITS2) and RPB2 gene from mycelia cultures were analyzed by Maximum Likelihood and Bayesian methods, whilst morphological features were documented from the corresponding herbarium vouchers. Congruent results were obtained from analyses of ribosomal LSU sequences downloaded from Genbank. The Bayesian analysis of ITS + RPB2 sequences gave the best resolution for the phylogenetic reconstructions and revealed the existence of three main lineages in the Trametes-clade: 1) a monospecific lineage represented by Artolenzites elegans 2) a lineage including the genus Pycnoporus in its traditional sense and several species usually classified in the genus Trametes ( T. cingulata, T. lactinea, T. ljubarskyi, T. menziesii) & 3) a lineage corresponding to the core genus Trametes, including type species of Trametes, Coriolopsis and Lenzites. The presence of a pseudostipe, aspect and structure of the abhymenial surface, colour change with 5% aqueous solutions of potassium hydroxide and topography of pigments on skeletal hyphae gave relevant morphological support to these clades. When the structure of the hymenial surface, presence of a black line below the tomentum and color of context (except for genus Pycnoporus) usually used in traditional polypore-classifications did not reveal any phylogenetic significance. A partial systematic arrangement of the Trametes clade is proposed, with the introduction of a new genus: Leiotrametes Welti & Courtec. gen. nov.. Two new combinations: Leiotrametes lactinea (Berk.) Welti & Courtec. comb. nov. and L. menziesii (Berk.) Welti & Courtec. comb. nov. are proposed. [ABSTRACT FROM AUTHOR]

The genus Pycnoporus forms a cosmopolitan group of four species belonging to the polyporoid white-rot fungi, the most representative group of homobasidiomycetes causing wood decay. Pycnoporus fungi are listed as food- and cosmetic-grade microorganisms and emerged in the early 1990s as a genus whose biochemistry, biodegradation and biotechnological properties have since been progressively detailed. First highlighted for their original metabolic pathways involved in the functionalization of plant cell wall aromatic compounds to yield high-value molecules, e.g. aromas and antioxidants, the Pycnoporus species were later explored for their potential to produce various enzymes of industrial interest, such as hydrolases and oxidases. However, the most noteworthy feature of the genus Pycnoporus is its ability to overproduce high redox potential laccase-a multi-copper extracellular phenoloxidase-as the predominant ligninolytic enzyme. A major potential use of the Pycnoporus fungi is thus to harness their laccases for various applications such as the bioconversion of agricultural by-products and raw plant materials into valuable products, the biopulping and biobleaching of paper pulp and the biodegradation of organopollutants, xenobiotics and industrial contaminants. All the studies performed in the last decade show the genus Pycnoporus to be a strong contender for white biotechnology. In this review, we describe the properties of Pycnoporus fungi in relation to their biotechnological applications and potential. [ABSTRACT FROM AUTHOR]

The Pycnoporus fungi are white-rot basidiomycetes listed as food- and cosmetic-grade microorganisms. Three high redox potential laccases from Pycnoporus coccineus and Pycnoporus sanguineus were tested and compared, with the commercial Suberase® as reference, for their ability to synthesise natural active oligomers from rutin (quercetin-3-rutinoside, one of the best-known naturally occurring flavonoid glycosides). The aim of this work was to develop a process with technical parameters (solvent, temperature, reaction time and raw materials) that were easy to scale up for industrial production and compatible with cosmetic and pharmaceutical formulation guidelines. The aqueous mixture of glycerol/ethanol/buffer described in this study met this requirement and allowed the solubilisation of rutin and its oxidative bioconversion into oligomers. The four flavonoid oligomer mixtures synthesised using laccases as catalysts were analysed by high performance liquid chromatography-diode array detection-negative electrospray ionisation-multistage mass spectrometry. Their chromatographic elution profiles were compared and 16 compounds were characterised and identified as dimers and trimers of rutin. The oligorutins were different in Suberase® and Pycnoporus laccase reaction mixtures. They were evaluated for their antioxidant, anti-inflammatory and anti-ageing activities on specific enzymatic targets such as cyclooxygenase (COX-2) and human matrix metalloproteinase 3 (MMP-3). Expressed in terms of IC, the flavonoid oligomers displayed a 2.5- to 3-fold higher superoxide scavenging activity than monomeric rutin. Pycnoporus laccase and Suberase® oligorutins led to an inhibition of COX-2 of about 35% and 70%, respectively, while monomeric rutin showed a near-negligible inhibition effect, less than about 10%. The best results on MMP-3 activity were obtained with rutin oligomers from P. sanguineus IMB W006-2 laccase and Suberase® with about 70-75% inhibition. [ABSTRACT FROM AUTHOR]