Reclassification of pneumocandin-producing anamorph, Glarea lozoyensis gen. et. sp. nov., previously identified as Zalerion arboricola

Natural Products Drug Discovery, Merck Research Laboratories, Rahway, New Jersey, 07065-0900, U.S.A.
Mycological Research (Impact Factor: 2.81). 02/1999; 103(2):179-192. DOI: 10.1017/S095375629800687X


The importance of pneumocandin BO as the fermentation-derived starting material for the antifungal drug candidate, MK-991, along with the identification of our production strain as Z. arboricola (ATCC 20868) as CBS prompted a search for other strains of Z. arboricola or Zalerion species with improved titres or that might produce natural pneumocandin analogues. Analysis of morphology, secondary metabolites profiles, and DNA fingerprinting demonstrated that ATCC 20868 was not congeneric with Z. arboricola. Ribosomal DNA sequences were compared among Zalerion species and pneumocandin-producing fungi and with rDNA sequences in GenBank. No good matches with sequences in GenBank were obtained for Z. arboricola or Z. maritimum, but for Z. varium, P. carpinea and ATCC 20868, relevant similarities were observed with ITS1 sequences from fungi of Leotiales. ATCC 20868 was phylogenetically more akin to P. carpinea, another pneumocandin producer, than initially suspected. The closest relative of ATCC 20868 seemed to be Hymenoscyphus monotropae. We conclude that the genus Zalerion is artificial; its species bear no phylogenetic relation among themselves. ATCC 20868 and Z. varium were related to fungi of the Leotiales. We propose a new anamorph genus and species, Glarea lozoyensis, to accommodate ATCC 20868.

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Available from: Gerald F Bills, Feb 27, 2015
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    • "The fungus belongs to the same phylogenetic lineage as Cyathicula or Crocicreas, an inconspicuous group of fungi that are weak parasites, endophytes of living plants or saprobes of senescent plants and plant litter. In the laboratory, the fungus readily colonized and sporulated on sterilized hardwood [25]. Its asexual sporulation (Figure 1b) resembled that of a heterogeneous group of asexually reproducing fungi known as aero-aquatic fungi that often colonize plant debris in periodically inundated habitats [29,30]. "
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    ABSTRACT: Background The antifungal therapy caspofungin is a semi-synthetic derivative of pneumocandin B0, a lipohexapeptide produced by the fungus Glarea lozoyensis, and was the first member of the echinocandin class approved for human therapy. The nonribosomal peptide synthetase (NRPS)-polyketide synthases (PKS) gene cluster responsible for pneumocandin biosynthesis from G. lozoyensis has not been elucidated to date. In this study, we report the elucidation of the pneumocandin biosynthetic gene cluster by whole genome sequencing of the G. lozoyensis wild-type strain ATCC 20868. Results The pneumocandin biosynthetic gene cluster contains a NRPS (GLNRPS4) and a PKS (GLPKS4) arranged in tandem, two cytochrome P450 monooxygenases, seven other modifying enzymes, and genes for L-homotyrosine biosynthesis, a component of the peptide core. Thus, the pneumocandin biosynthetic gene cluster is significantly more autonomous and organized than that of the recently characterized echinocandin B gene cluster. Disruption mutants of GLNRPS4 and GLPKS4 no longer produced the pneumocandins (A0 and B0), and the Δglnrps4 and Δglpks4 mutants lost antifungal activity against the human pathogenic fungus Candida albicans. In addition to pneumocandins, the G. lozoyensis genome encodes a rich repertoire of natural product-encoding genes including 24 PKSs, six NRPSs, five PKS-NRPS hybrids, two dimethylallyl tryptophan synthases, and 14 terpene synthases. Conclusions Characterization of the gene cluster provides a blueprint for engineering new pneumocandin derivatives with improved pharmacological properties. Whole genome estimation of the secondary metabolite-encoding genes from G. lozoyensis provides yet another example of the huge potential for drug discovery from natural products from the fungal kingdom.
    BMC Genomics 05/2013; 14(1):339. DOI:10.1186/1471-2164-14-339 · 3.99 Impact Factor
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    • "Nine strains forming sterile, dense, brown aerial mycelium shared 97–99% similarity of their ITS rDNA sequences. In a partial analysis (data not shown), these strains fell into two moderately supported clades that were sister to sequence AF169307 from the ex-type strain of Zalerion arboricola (Bills et al. 1999). After 1 year of cultivation at the lowered temperature, the strains began to produce conidia that were similar in shape and size to those of Z. arboricola, which points to higher variability in the ITS rDNA of Z. arboricola rather than to a new species. "
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    ABSTRACT: The unmanaged Norway spruce montane forests in the Bohemian Forest National Park (Czech Republic) suffered from repeated large-scale bark beetle outbreaks in last decade. In this study, the diversity of culturable foliar endophyte microfungi in needles originating from eleven recently wind-fallen trees in this area was surveyed. Our aims were to describe their diversity and to determine the relative host and organ specificities of isolated endophyte species to estimate the species pool and abundance of foliar endophytes before the forest degradation. Microfungi were isolated from surface-sterilized needles, and the outgrowing strains were identified based on morphological and molecular characteristics (analyses of ITS1, ITS2 and partial 28S rDNA). Fungal communities in the needles were diverse, with ascomycetes (mostly anamorphs of Helotiales) dominating basidiomycetes. The most frequent species (Phacidiopycnis sp., Cistella acuum, Sirococcus sp. and two species of Chalara) did not correspond with those recorded in previous studies of Picea spp. For example, the widely distributed Lophodermium piceae was rarely recorded in this study. This pattern may be caused by different methods of sterilization and cultivation or by physiological characteristics of the needles, or it may reflect the species distribution in the studied area. Members of the Helotiales, along with sequences from GenBank, showed substantial overlap in host affinities, most prominently between Pinus and Picea, and also among species from distant plant lineages.
    Fungal diversity 05/2012; 54(1). DOI:10.1007/s13225-011-0112-2 · 6.22 Impact Factor
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    • "Undoubtedly, one of the most important antifungal agents discovered in recent decades was pneumocandin B 0 , a cyclic lipopeptide (160). This compound together with pneumocandin A 0 (161) and other derivatives were produced by Glarea lozoyensis, a dematiaceous hyphomycete isolated from filtrate pond water in Spain (Bills et al. 1999; Schmatz et al. 1992a, b). The in vitro assays showed the enormous potential of pneumocandins where 160 was the best, at very low concentrations against C. albicans (MIC = 0.06 lg/ ml), in the assay with the enzyme 1,3-b-D-glucan (IC 50 = 0.06 lg/ll) and in vivo efficiency against Pneumocystis carinni in mice showed a ED 50 between 0.15 and 2.5 mg/kg (Schmatz et al. 1992b). "
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    ABSTRACT: Microorganisms are recognized worldwide as the major source of secondary metabolites with mega diverse structures and promissory biological activities. However, as yet many of them remain little or under-explored like the microbiota from freshwater aquatic ecosystems. In the present review, we undertook a recompilation of metabolites reported with pesticidal properties from microalgae (cyanobacteria and green algae) and fungi, specifically from freshwater aquatic habitats. KeywordsBioactive metabolites–Cyanobacteria–Freshwater ecosystems–Fungi–Microalgae
    Phytochemistry Reviews 06/2011; 10(2):261-286. DOI:10.1007/s11101-010-9192-y · 2.41 Impact Factor
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