A systematic assessment ofMorchellausing RFLP analysis of the 28S ribosomal RNA gene

An updated LSU database and pipeline for environmental DNA identification of arbuscular mycorrhizal fungi

Recent work established a backbone reference tree and phylogenetic placement pipeline for identification of arbuscular mycorrhizal fungal (AMF) large subunit (LSU) rDNA environmental sequences. Our previously published pipeline allowed any environmental sequence to be identified as putative AMF or within one of the major families. Despite this contribution, difficulties in implementation of the pipeline remain. Here, we present an updated database and pipeline with (1) an expanded backbone tree to include four newly described genera and (2) several changes to improve ease and consistency of implementation. In particular, packages required for the pipeline are now installed as a single folder (conda environment) and the pipeline has been tested across three university computing clusters. This updated backbone tree and pipeline will enable broadened adoption by the community, advancing our understanding of these ubiquitous and ecologically important fungi.

Rare but widespread: A systematic revision of the truffle-forming genera Destuntzia and Kjeldsenia and the formation of a new genus, Hosakaea

Here we present the results of taxonomic and systematic study of the rare truffle-forming genera Destuntzia and Kjeldsenia. Truffle-forming fungi are difficult to study due to their reduced morphological features and their cryptic, hypogeous fruiting habits. The rare occurrence of Destuntzia and Kjeldsenia further compounds these difficulties due to the lack of adequate material for study. Recent forays in North Carolina and Tennessee recovered new specimens of another rarely collected fungus, Octaviania purpurea. Morphological and phylogenetic analysis revealed that Octaviania purpurea is a member of the genus Destuntzia, and this led us to reevaluate the taxonomic status and systematic relationships of other Destuntzia species. We performed a multilocus phylogenetic analysis of Destuntzia specimens deposited in public fungaria, including all available type material, and environmental sequences from animal scat and soil. Our analyses indicate that Destuntzia is a member of the family Claustulaceae within the order Phallales and is a close relative of Kjeldsenia. Results of our phylogenetic analysis infer that three species originally described in the genus Destuntzia are members of the genus Kjeldsenia. We propose three new combinations in Kjeldsenia to accommodate these species as well as a new combination in Destuntzia to accommodate Octaviania purpurea. We also describe a new genus in Claustulaceae, Hosakaea, to accommodate a closely affiliated species, Octaviania violascens. Finally, we transfer the genus Destunzia into the family Claustulaceae and emend the description of the family. The newly proposed combinations in Destuntzia and Kjeldsenia significantly expand the known geographic ranges of both genera. The data from metabarcode analysis of scat and soil also reveal several additional undescribed species that expand these ranges well beyond those suggested by basidiomata collections. Systematic placement of Destuntzia in the saprotrophic order Phallales suggests that this genus is not ectomycorrhizal, and the ecological implications of this systematic revision are discussed.

Lanspora dorisauae, a new marine fungus from rocky shores in Taiwan

This article reports a new marine fungus, Lanspora dorisauae (Phomatosporales, Sordariomycetes, Ascomycota), on trapped wood collected in coastal sites of Taiwan. This new fungus was subjected to a morphological examination and a phylogenetic study based on a combined analysis of the 18S, 28S, ITS rDNA, TEF1-α and RPB2 genes. Lanspora dorisauae is characterized by dark-coloured ascomata with a short neck, periphysate ostioles, subclavate, deliquescing asci without an apical ring, presence of wide paraphyses, striated wall ascospores with crown-like appendages on one pole of the ascospores. Phylogenetically, L. dorisauae grouped with Lanspora coronata (type species) with strong support. Lanspora coronata lacks paraphyses and appendages occur on both ends of the ascospores, while paraphyses are present and ascospore appendage is unipolar in L. dorisauae. Lanspora cylindrospora formed a sister clade with L. coronata and L. dorisauae, but it significantly differs in morphology with the latter two species in having cylindrical asci with an apical J- ring, smooth ascospore wall and no ascospore appendages, and may be better referred to a new genus. Lanspora, together with Phomatospora and Tenuimurus, belong to the Phomatosporaceae, Phomatosporales. Phomatospora berkeleyi should be sequenced to test the validity of the order Phomatosporales and the family Phomatosporaceae.

Arbuscular Mycorrhizal Fungi Taxa Show Variable Patterns of Micro-Scale Dispersal in Prairie Restorations

Human land use disturbance is a major contributor to the loss of natural plant communities, and this is particularly true in areas used for agriculture, such as the Midwestern tallgrass prairies of the United States. Previous work has shown that arbuscular mycorrhizal fungi (AMF) additions can increase native plant survival and success in plant community restorations, but the dispersal of AMF in these systems is poorly understood. In this study, we examined the dispersal of AMF taxa inoculated into four tallgrass prairie restorations. At each site, we inoculated native plant species with greenhouse-cultured native AMF taxa or whole soil collected from a nearby unplowed prairie. We monitored AMF dispersal, AMF biomass, plant growth, and plant community composition, at different distances from inoculation. In two sites, we assessed the role of plant hosts in dispersal, by placing known AMF hosts in a “bridge” and “island” pattern on either side of the inoculation points. We found that AMF taxa differ in their dispersal ability, with some taxa spreading to 2-m in the first year and others remaining closer to the inoculation point. We also found evidence that AMF spread altered non-inoculated neighboring plant growth and community composition in certain sites. These results represent the most comprehensive attempt to date to evaluate AMF spread.

Two New Species and Three New Records of Ascomycetes in Korea

During a survey of plant-inhabiting fungi and water niches from Korea, noteworthy fungi were collected; among them, two new species, Paracamarosporium noviaquum sp. nov. and Phyllosticta gwangjuensis sp. nov., are described based on morphology and multi-gene phylogenies. Paracamarosporium noviaquum was characterized by its production of 1-celled and 2-celled conidia, forming conidiomata on only potato dextrose agar medium. Phyllosticta gwangjuensis was characterized by conidia hyaline, ovoid to ellipsoid shape, rounded at both ends, containing numerous guttulae or with a single large central guttule. Additional species were identified as Cosmospora lavitskiae, Monochaetia cameliae, and Roussoella doimaesalongensis, which are reported as new record species from Korea. Detailed descriptions and illustrations of these taxa are provided herein.

Discovery of Novel Backusella (Backusellaceae, Mucorales) Isolated from Invertebrates and Toads in Cheongyang, Korea

Three novel fungal species, Backusella chlamydospora sp. nov., B. koreana sp. nov., and B. thermophila sp. nov., as well as two new records, B. oblongielliptica and B. oblongispora, were found in Cheongyang, Korea, during an investigation of fungal species from invertebrates and toads. All species are described here using morphological characters and sequence data from internal transcribed spacer sequences of ribosomal DNA and large subunit of the ribosomal DNA. Backusella chlamydospora is different from other Backusella species by producing chlamydospores. Backusella koreana can be distinguished from other Backusella species by producing abundant yeast-like cells. Backusella thermophila is characterized by a variable (subglobose to oblong, applanate to oval, conical and ellipsoidal to pyriform) columellae and grows well at 37 °C. Multigene phylogenetic analyses of the combined ITS and LSU rDNA sequences data generated from maximum likelihood and MrBayes analyses indicate that B. chlamydospora, B. koreana, and B. thermophila form distinct lineages in the family Backusellaceae. Detailed descriptions, illustrations, phylogenetic tree, and taxonomic key to the Backusella species present in Korea are provided.

Brahmaculus gen. nov. (Leotiomycetes, Chlorociboriaceae)

A second genus in Chlorociboriaceae is described here as Brahmaculusgen. nov. Macroscopically distinctive, all species have bright yellow apothecia with several apothecial cups held on short branches at the tip of a long stipe. The genus is widely distributed across the Southern Hemisphere; the four new species described here include two from Chile (B.magellanicussp. nov., B.osornoensissp. nov.) and one each from New Zealand (B.moonlighticussp. nov.) and Australia (B.packhamiaesp. nov.). They differ from species referred to Chlorociboria, the only other genus in Chlorociboriaceae, in their terrestrial habitat and ascomata that are noticeably more hairy than the known Chlorociboria species, most of which have apothecia with short, macroscopically indistinct hair-like elements. Based on our analyses, Chlorociboria as accepted here is paraphyletic. Additional study is needed to clarify where alternative, monophyletic generic limits should be drawn and how these genera may be recognised morphologically. Also described here are three new Chlorociboria spp. from New Zealand (C.metrosiderisp. nov., C.solandrisp. nov., C.subtilissp. nov.), distinctive in developing on dead leaves rather than wood and in two of them not forming the green pigmentation characteristic of most Chlorociboria species. New Zealand specimens previously incorrectly identified as Chlorociboriaargentinensis are provided with a new name, C.novae-zelandiaesp. nov.

Three novel species and a new record of Daldinia (Hypoxylaceae) from Thailand

In an investigation of stromatic Xylariales in Thailand, several specimens of Daldinia were discovered. Three novel species (D. flavogranulata, D. phadaengensis, and D. chiangdaoensis) were recognized from a molecular phylogeny based on concatenated ITS, LSU, RPB2, and TUB2 sequence data, combined with morphological characters and secondary metabolite profiles based on high performance liquid chromatography coupled to diode array detection and mass spectrometry (HPLC-MS). The major components detected were cytochalasins (in D. flavogranulata and D. chiangdaoensis) and daldinin type azaphilones (in D. phadaengensis). In addition, D. brachysperma, which had hitherto only been reported from America, was found for the first time in Asia. Its phylogenetic affinities were studied, confirming previous suspicions from morphological comparisons that the species is closely related to D. eschscholtzii and D. bambusicola, both common in Thailand. Daldinia flavogranulata, one of the new taxa, was found to be closely related to the same taxa. The other two novel species, D. phadaengensis and D. chiangdaoensis, share characters with D. korfii and D. kretzschmarioides, respectively.

Phylogeny- and morphology-based recognition of new species in the spider-parasitic genus Gibellula (Hypocreales, Cordycipitaceae) from Thailand

Thailand is known to be a part of what is called the Indo-Burma biodiversity hotspot, hosting a vast array of organisms across its diverse ecosystems. This is reflected by the increasing number of new species described over time, especially fungi. However, a very few fungal species from the specialized spider-parasitic genus Gibellula have ever been reported from this region. A survey of invertebrate-pathogenic fungi in Thailand over several decades has led to the discovery of a number of fungal specimens with affinities to this genus. Integration of morphological traits into multi-locus phylogenetic analysis uncovered four new species: G.cebrennini, G.fusiformispora, G.pigmentosinum, and G.scorpioides. All these appear to be exclusively linked with torrubiella-like sexual morphs with the presence of granulomanus-like asexual morph in G.pigmentosinum and G.cebrennini. A remarkably high host specificity of these new species towards their spider hosts was revealed, and for the first time, evidence is presented for manipulation of host behavior in G.scorpioides.

Phylogenetic and Chemotaxonomic Studies Confirm the Affinities of Stromatoneurospora phoenix to the Coprophilous Xylariaceae

The genus Stromatoneurospora was erected in 1973 by Jong and Davis to accommodate the pyrophilic pyrenomycete Sphaeria phoenix and has traditionally been placed in the family Xylariaceae based on morphological features. However, no living culture of this genus has so far been available in the public domain. Molecular data were restricted to an internal transcribed spacer (ITS) sequence that only confirmed the familial position, and was generated from a strain that is not deposited in a public culture collection. We have recently collected fresh material and were able to culture this fungus from Thailand. The secondary metabolites of this strains were analysed after fermentation in multiple media. The the prominent components of these fermentation were purified, using preparative chromatography. Aside from two new eremophilane sesquiterpenoids named phoenixilanes A–B (1–2), four other components that are known from species of the xylariaceous genera Xylaria and Poronia were identified by spectral methods (nuclear magnetic resonance spectroscopy and high resolution mass spectrometry). Notably, (−)-(R)-6-hydroxy-3-methyl-4-dihydroisocoumarin-5-carboxylic acid (6) has not been reported as a natural product before. Moreover, DNA sequences of Stromatoneurospora phoenix clustered with members of the genera Poronia and Podosordaria in a multi-locus molecular phylogeny. These results confirmed that the genus belongs to the same evolutionary lineage as the coprophilic Xylariaceae. The results also suggest that this lineage has evolved independently from the plant-inhabiting saprotrophs and endophytes that are closely related to the genus Xylaria. These findings are discussed in relation to some theories about the endophytic vs. the pyrophilic/coprophilic fungal life style.

High diversity of Morchella and a novel lineage of the Esculenta clade from the north Qinling Mountains revealed by GCPSR-based study

China is a mainland country rich in natural morel recourses, having records of half of the worldwide 61 morel phylospecies. In this study, 31 collections of ascocarps from the north Qinling Mountains, 4 collections of commercial cultivars from the south Qinling Mountains, and 3 Morchella mycelium clones from commercial cultivars were investigated using the genealogical concordance phylogenetic species recognition (GCPSR) method. Maximum-likelihood was employed for the construction of phylogenetic trees. A total of five phylogenetic species were found among the 38 collections, namely Morchella sp. Mes-8, Mes-9, Mes-13, and Mes-25, and Morchella chensiensis (IF556780), in addition to the false morel (Verpa bohemica). The identification of cultivated Morchella sp. Mel-2, Mel-6, Mel-10, and Mel-12 coincided with that of the commercial farms. A total of 80% (4/5) of yellow morels were new records for the Qinling region, except Mes-19; moreover, a novel monophyletic lineage, Morchella chensiensis, was found to be distinct from the previously reported phylospecies by single gene and combined genes analysis, thus being herein proposed as a new phylospecies. All collections from this study showed continental endemism, and all Qinling Mountains collections were grouped together in rDNA phylogenetic trees. The study provided insights on biodiversities in this key region of China.

A Novel PCR-Based Approach for Rapid Identification of Morchella sextelata Using Species-Specific Primers

Morels are precious and rare edible mushroom, which contain 61 species. It is difficult to identify the species of morels based on morphological characteristics. In recent years, morels cultivation technology has made great progress, Morchella sextelata has been cultivated in China widely. In this study, a PCR-based approach was developed for identification of Morchella sextelata, based on a 190-bp segment of internal transcribed spacer (ITS). The species-specific primer, MS1F/MS1R, was designed based on the alignment of sequence obtained from the 20 representative cultivated body fruit of Morchella sextelata as well as 10 sequence data available in Genbank. Verifying the species-specific primer pair demonstrated generation of an amplicon from extracted DNA of Morchella sextelata. The primer pair was also applied and tested for five other species of morels and eight common mushrooms from other genus. This novel PCR assay allowed a rapid and effective quality evaluation of Morchella sextelata.

The Cedrus-associated truffle Trappeindia himalayensis is a morphologically unique and phylogenetically divergent species of Rhizopogon

In the northwestern Himalayan mountains of India, the hypogeous sequestrate fungus Trappeindia himalayensis is harvested from forests dominated by the ectomycorrhizal tree Cedrus deodara (Himalayan cedar). This truffle has basidiospores that are ornamented with raised reticulation. The original description of Trappeindia himalayensis suggested that the gleba of this species is similar to young specimens of Scleroderma (Boletales), whereas its basidiospores are ornamented with raised reticulation, suggesting a morphological affinity to Leucogaster (Russulales) or Strobilomyces (Boletales). Given this systematic ambiguity, we have generated DNA sequence data from type material and other herbarium specimens and present the first molecular phylogenetic analysis of this unusual Cedrus-associated truffle. Despite the irregular ornamented basidiospore morphology, T. himalayensis is resolved within the genus Rhizopogon (Suillineae, Boletales) and represents a unique lineage that has not been previously detected. All known Rhizopogon species possess an ectomycorrhizal trophic mode, and because of its placement in this lineage, it is likely that Trappeindia himalayensis is an ectomycorrhizal partner of Cedrus deodara. This study highlights the importance of generating sequence data from herbarium specimens in order to identify fungal biodiversity and clarify the systematic relationships of poorly documented fungi.

Overview of Phacidiales, including Aotearoamyces gen. nov. on Nothofagus

The new genus Aotearoamyces is proposed to accommodate a single species that was repeatedly collected on fallen wood in Nothofagaceae forests of New Zealand and was previously misidentified as a Claussenomyces species. This monotypic genus belongs to Tympanidaceae, a recently erected family in Phacidiales. Aotearoamyces is differentiated from other Tympanidaceae by phragmospores that do not form conidia either in or outside the asci, an exciple of textura intricata with hyphae widely spaced and strongly gelatinized (plectenchyma), and apically flexuous, partly helicoid paraphyses. The asexual morph was studied in pure culture. Phylogenetic analyses of combined SSU, ITS and LSU sequences strongly support a sister relationship between the sexually typified Aotearoamyces and the asexually typified “Collophorina” paarla characterized morphologically by forming endoconidia, a feature not found in the genetically distinct type species of Collophorina. Based on our molecular results, we place the genus Epithamnolia in the Mniaecia lineage within Phacidiales.

Validation of Internal Control Genes for Quantitative Real-Time PCR Gene Expression Analysis in Morchella

The reliability of qRT-PCR results depend on the stability of reference genes used for normalization, suggesting the necessity of identification of reference genes before gene expression analysis. Morels are edible mushrooms well-known across the world and highly prized by many culinary kitchens. Here, several candidate genes were selected and designed according to the Morchella importuna transcriptome data. The stability of the candidate genes was evaluated with geNorm and NormFinder under three different experimental conditions, and several genes with excellent stability were selected. The extensive adaptability of the selected genes was tested in ten Morchella species. Results from the three experimental conditions revealed that ACT1 and INTF7 were the most prominent genes in Morchella, CYC3 was the most stable gene in different development stages, INTF4/AEF3 were the top-ranked genes across carbon sources, while INTF3/CYC3 pair showed the robust stability for temperature stress treatment. We suggest using ACT1, AEF3, CYC3, INTF3, INTF4 and INTF7 as reference genes for gene expression analysis studies for any of the 10 Morchella strains tested in this study. The stability and practicality of the gene, vacuolar protein sorting (INTF3), vacuolar ATP synthase (INTF4) and14-3-3 protein (INTF7) involving the basic biological processes were validated for the first time as the candidate reference genes for quantitative PCR. Furthermore, the stability of the reference genes was found to vary under the three different experimental conditions, indicating the importance of identifying specific reference genes for particular conditions.

Determination and production of antimicrobial compounds by Aspergillus clavatonanicus strain MJ31, an endophytic fungus from Mirabilis jalapa L. using UPLC-ESI-MS/MS and TD-GC-MS analysis

Endophytic fungi associated with medicinal plants are reported as potent producers of diverse classes of secondary metabolites. In the present study, an endophytic fungi, Aspergillus clavatonanicus strain MJ31, exhibiting significant antimicrobial activity was isolated from roots of Mirabilis jalapa L., was identified by sequencing three nuclear genes i.e. internal transcribed spacers ribosomal RNA (ITS rRNA), 28S ribosomal RNA (28S rRNA) and translation elongation factor 1- alpha (EF 1α). Ethyl acetate extract of strain MJ31displayed significant antimicrobial potential against Bacillus subtilis, followed by Micrococccus luteus and Staphylococcus aureus with minimum inhibitory concentrations (MIC) of 0.078, 0.156 and 0.312 mg/ml respectively. In addition, the strain was evaluated for its ability to synthesize bioactive compounds by the amplification of polyketide synthase (PKS) and non ribosomal peptide synthetase (NRPS) genes. Further, seven antibiotics (miconazole, ketoconazole, fluconazole, ampicillin, streptomycin, chloramphenicol, and rifampicin) were detected and quantified using UPLC-ESI-MS/MS. Additionally, thermal desorption-gas chromatography mass spectrometry (TD-GC-MS) analysis of strain MJ31 showed the presence of 28 volatile compounds. This is the first report on A. clavatonanicus as an endophyte obtained from M. jalapa. We conclude that A. clavatonanicus strain MJ31 has prolific antimicrobial potential against both plant and human pathogens and can be exploited for the discovery of new antimicrobial compounds and could be an alternate source for the production of secondary metabolites.

Harorepupu aotearoa (Onygenales) gen. sp. nov.; a threatened fungus from shells of Powelliphanta and Paryphanta snails (Rhytididae)

A cleistothecial fungus, known only from the shells of giant land snails of the family Rhytidae, is described as a new genus and species within Onygenales, Harorepupu aotearoa gen. sp. nov. Known only from the sexual morph, this fungus is characterized morphologically by a membranous ascoma with no appendages and ascospores with a sparse network of ridges. Ribosomal DNA sequences place the new species within Onygenales, but comparison with the known genetic diversity within the order linked it to no existing genus or family. It is the first species of Onygenales reported from the shells of terrestrial snails. This fungus has been listed as Critically Endangered in New Zealand and has been previously referred to as ‘Trichocomaceae gen. nov.’ in those threat lists.

Westerdykella reniformis sp. nov., producing the antibiotic metabolites melinacidin IV and chetracin B

Westerdykella reniformis Ebead & Overy sp. nov. is described based on morphology and phylogenetic analyses using ITS, nLSU rDNA, and β-tubulin gene sequences. Westerdykella reniformis is characterized by the production of cleistothecioid ascomata, containing small globose to subglobose asci with 32, aseptate, dark colored, pronouncedly reniform ascospores having a concave central groove. The isolate was obtained from a red alga (Polysiphonia sp.) collected from the tidal zone in Canada at low tide. Organic extracts enriched in extrolites, obtained from fermentation on a rice-based media, inhibited the growth of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecium (VRE), S. warneri, and Proteus vulgaris. Presented here is the identification of the compounds responsible for the observed antimicrobial activity, the taxonomic description of W. reniformis, and a dichotomous key to the known species of Westerdykella based on macro- and micromorphological characters.

Annulatascus nilensis sp. nov., a new freshwater ascomycete from the River Nile, Egypt

Annulatascus nilensis sp. nov., from freshwater habitats in Egypt, is described, illustrated and compared to other species in the genus. Phylogenetic analyses of its LSU rDNA sequence with similar fungi placed the new species in the genus Annulatascus (Annulatascaceae, Sordariomycetidae incertae sedis). Annulatascus nilensis is characterized by immersed ascomata with an ascomatal neck oriented horizontally to the substrate surface, asci with a long, narrow stalk and massive bipartite apical ring, and 5-11-septate, hyaline ascospores surrounded by a large irregular, granular sheath that is not seen in water.

Hydronaphthalenones and a dihydroramulosin from the endophytic fungus PSU-N24

Three new hydronaphthalenone derivatives (1-3) and one new dihydroramulosin derivative (4), were isolated from the endophytic fungus PSU-N24 together with eight known compounds. Their structures were elucidated by spectroscopic methods. Griseofulvin (9) displayed strong antifungal activity against Microsporum gypseum SH-MU-4 with a minimum inhibitory concentration (MIC) value of 2 microg/ml while all metabolites exhibited very weak antibacterial activity (MIC value>or=128 microg/ml) against Staphylococcus aureus, both standard and methicillin-resistant strains. 3-(2-Hydroxypropyl)benzene-1,2-diol (10) showed moderate antimalarial activity against Plasmodiun falciparum with an IC(50) value of 6.68 microg/ml. For antimycobacterial activity against Mycobacterium tuberculosis, compound 3 gave the best activity with the MIC value of 12.50 microg/ml.

Molecular systematics of the marine Dothideomycetes

Phylogenetic analyses of four nuclear genes, namely the large and small subunits of the nuclear ribosomal RNA, transcription elongation factor 1-alpha and the second largest RNA polymerase II subunit, established that the ecological group of marine bitunicate ascomycetes has representatives in the orders Capnodiales, Hysteriales, Jahnulales, Mytilinidiales, Patellariales and Pleosporales. Most of the fungi sequenced were intertidal mangrove taxa and belong to members of 12 families in the Pleosporales: Aigialaceae, Didymellaceae,Leptosphaeriaceae, Lenthitheciaceae, Lophiostomataceae, Massarinaceae,Montagnulaceae, Morosphaeriaceae, Phaeosphaeriaceae, Pleosporaceae, Testudinaceae and Trematosphaeriaceae. Two new families are described: Aigialaceae and Morosphaeriaceae, and three new genera proposed: Halomassarina, Morosphaeria and Rimora. Few marine species are reported from the Dothideomycetidae (e.g. Mycosphaerellaceae, Capnodiales), a group poorly studied at the molecular level. New marine lineages include the Testudinaceae and Manglicolaguatemalensis in the Jahnulales. Significantly, most marine Dothideomycetes are intertidal tropical species with only a few from temperate regions on salt marsh plants (Spartina species and Juncus roemerianus), and rarely totally submerged (e.g. Halotthia posidoniae and Pontoporeia biturbinata on the seagrasses Posidonia oceanica and Cymodocea nodosum). Specific attention is given to the adaptation of the Dothideomycetes to the marine milieu, new lineages of marine fungi and their host specificity.

Epoxydons and a pyrone from the marine-derived fungus Nigrospora sp. PSU-F5

Nigrospoxydons A-C (1- 3) and nigrosporapyrone (4), four new metabolites, were isolated from the marine-derived fungus Nigrospora sp. PSU-F5 together with nine known compounds. Their structures were elucidated by spectroscopic methods, mainly 1D and 2D NMR spectroscopic techniques. The antibacterial activity against the standard Staphylococcus aureus ATCC 25923 and methicillin-resistant S. aureus was evaluated.

Effect of culture conditions on antifouling compound production of a sponge-associated fungus

Microorganisms associated with invertebrate hosts have long been suggested to be a source for bioactive metabolites. In this study, we reported that a sponge-associated fungus, Letendraea helminthicola, produced two antifouling compounds: 3-methyl-N-(2-phenylethyl) butanamide and cyclo(D-Pro-D-Phe). To optimize the production of these antifouling compounds, we then examined the production of compounds under different culture conditions (temperature, salinity, pH, and carbon and nitrogen sources). This fungus grew well and produced more compounds at temperatures between 18 and 30 degrees C; the fungus grew well at 75 parts per thousand (ppt) salinity but produced the highest amount of antifouling compounds at 30 and 45 ppt. The optimal initial pH value for mycelial growth was 5.5 to 6.5, whereas the production of the antifouling compounds was maximized at pH 3.5 and 4.5. Glucose and xylose (as carbon sources) increased the production of antifouling compounds. Yeast extract and peptone (as nitrogen sources) maximized the production of mycelial biomass and antifouling compounds. Our results indicate that culture conditions greatly affect the production of bioactive compounds from mycelial fungal cultures as exemplified by strain L. helminthicola and that the conditions favorable for fungal growth may not be the best conditions for bioactive compound production.

Diversity of the internal transcribed spacer of rDNA in morels

The internal transcribed spacer (ITS) of rDNA was analysed by PCR/RFLP in 66 strains belonging to 11 putative species of the Morchellaceae and 3 species of the Discinaceae. For certain taxa, in particular Morchella esculenta, Morchella conica, and Morchella elata, isolates from distant geographical origins were available. Nevertheless, no intraspecific variations of ITS length and restriction was noted. All genera were separated and within Morchella; four putative species could be clearly distinguished in the group of the yellow morels (sectio adnatae). In contrast, no distinction could be obtained between the compared taxa in the group of the black morels (sectio distantes). Sequence analyses of the ITS were performed in one strain of seven putative Morchella. The sequence comparison confirmed the distinctions within the yellow morels and allowed us to separate one putative taxon from the others in black morels. Only the 5,8 gene could be aligned in all sequenced samples. The ITS1 and ITS2 sectors could only be aligned within the black and yellow morels, respectively. The genetic and phylogenetic distances between black and yellow morels, respectively revealed by maximum parsimony and neighbour joining analyses, both confirm the great distance between these species groups and address the question of a separation in the genus Morchella.Key words: Morchellaceae, Discinaceae, ITS.

Genetics and systematics of North American populations ofMorchella

Our knowledge of the genetics and systematics of the genus Morchella in North America has increased greatly because of many recent field and laboratory studies. Field studies have expanded distribution records and provided insights on ascoma development. More detailed morphological studies have improved species descriptions and simplified species identification. Mating studies between monosporous strains and the formation of presumptive heterokaryons have given evidence for species delimitation. The isolation of chemical products and antigen comparisons using ELISA have provided additional support for species concepts. Electrophoretic studies of allelic variation have given insights into the genetic structure of morels from different geographical areas. Sequence data from the nuclear large rDNA (28S) have been used to infer phylogenetic relationships among species. Additional insights have been obtained from physiological and environmental studies on sclerotium formation that have enabled the production of ascoma in culture. This has led to the filing of patents, commercial production, and the availability of growing kits. Key words: Morchella, systematics, genetics, North America, review.