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Abstract Karst caves are distinctive ecosystems that have limited nutrients, darkness, low to moderate temperatures, and high moisture levels, which allow for a diverse range of fungal communities to thrive. Despite their significance, little is understood about the fungi found in karst caves in Thailand. In 2019, we studied the cultured mycobiota from five substrate types (air, water, rock, soil/sediment, and organic debris) in two karst caves (Le Stegodon and Phu Pha Phet Caves) of the Satun UNESCO Global Geopark, southern Thailand. A cumulative count of 829 distinct fungal morphological types was identified, encompassing 319 fungal culturable were observed. Based on preliminary analyses of the internal transcribed spacer (ITS) sequence using BLAST searches, the most common phylum among the fungal morphotypes was Ascomycota, harboring 282 species in 91 genera, 93.4% of which were distributed in the classes Eurotiomycetes, Sordariomycetes, and Dothideomycetes. The most common fungal genera identified in the two karst caves were Aspergillus, Penicillium, Cladosporium, Talaromyces, Xylaria, and Trichoderma, with 45, 41, 24, 14, 14, and 6 species identified, respectively. Discovering fungi in Thai karst caves highlights the extensive fungal diversity in the Satun UNESCO Global Geopark, implying undiscovered species, and emphasizing the need for comprehensive investigations in other unexplored Thai karst caves.

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.

Karst caves are oligotrophic environments that appear to support a high diversity of fungi. Studies of fungi in Thailand’s caves are limited. During a 2019 exploration of the mycobiota associated with soil samples from a karst cave, namely, Phu Pha Phet in the Satun UNESCO Global Geopark in Satun Province, southern Thailand, two previously undescribed fungi belonging to Talaromyces (Trichocomaceae, Eurotiales, Eurotiomycetes) were studied using a polyphasic approach combining phenotypic and molecular data. Based on datasets of four loci (ITS, BenA, CaM, and RPB2), phylogenetic trees of the section Trachyspermi were constructed, and two new species—Talaromyces phuphaphetensis sp. nov. and T. satunensis sp. nov.—phylogenetically related to T. subericola, T. resinae, and T. brasiliensis, are described. Detailed descriptions and illustrations of the new species are provided. This study increases the number of cave-dwelling soil fungi discovered in Thailand’s Satun UNESCO Global Geopark, which appears to be a unique environment with a high potential for discovering fungal species previously undescribed.

Fusarium infections in humans (fusariosis) and in economically important plants involve species of several Fusarium species complexes. Species of the Fusarium solani species complex (FSSC) are the most frequent cause of human fusariosis. The FSSC comprises more than 60 closely related species that can be separated into three major clades by multi-locus sequence typing (MLST) using translation elongation factor 1-alpha (TEF1-α) and RNA polymerase II (RPB2) DNA sequences. The MLST nomenclature for clade 3 of the FSSC assigns numbers to species types (e.g., FSSC 2) and lowercase letters to identify unique haplotypes. The aim of this study was to analyse the genotypic and phenotypic characteristics of 15 environmental and 15 clinical FSSC isolates from Malaysia. MLST was used for the genotypic characterisation of FSSC isolates from various locations within Malaysia, which was complemented by their morphological characterisation on potato dextrose and carnation leaf agar. MLST identified eight different FSSC species: thirteen Fusarium keratoplasticum (i.e., FSSC 2), six Fusarium suttonianum (FSSC 20), five Fusarium falciforme (FSSC 3+4), two Fusarium cyanescens (FSSC 27), and one each of Fusarium petroliphilum (FSSC 1), Fusarium waltergamsii (FSSC 7), Fusarium sp. (FSSC 12), and Fusarium striatum (FSSC 21). Consistent with previous reports from Malaysia, most (11 of 15) clinical FSSC isolates were F. keratoplasticum and the majority (9 of 15) of environmental isolates were F. suttonianum (5) or F. falciforme (4) strains. The taxonomic relationships of the isolates were resolved phylogenetically. The eight Fusarium species also showed distinct morphological characteristics, but these were less clearly defined and reached across species boundaries. Although TEF1-α and RPB2 sequences were sufficient for the species identification of most FSSC isolates, a more precise MLST scheme needs to be established to reliably assign individual isolates of the species-rich FSSC to their geographically-, epidemiologically-, and host-associated sub-lineages.

Thraustochytrids, marine protists, have attracted attention as a proven alternative source of polyunsaturated fatty acids (PUFAs). We isolated a high diversity of thraustochytrids from Thailand and tested their potential use in the production of high-value fatty acids. The isolated thraustochytrids can be categorized into seven major groups based on unique morphological features, molecular phylogeny and fatty acid profiles. Two of the seven isolated thraustochytrid groups could potentially be new lineages in the Labyrinthulomycetes. The production of total fatty acid (TFA) from these thraustochytrids ranged from 2.4 to 35.6% (w/w), with biomass varying from 0.3 to 8.9 g l-1. The production of arachidonic acid (C20:4) ranged from 0.3 to 8.2% of TFA, eicosapentaenoic acid (C20:5) from 1.5 to 12.4%, docosapentaenoic acid (C22:5) from 9.7 to 27.3%, and docosahexaenoic acid (C22:6) from 14.4 to 51.7%. In addition, the cryopreservation of selected thraustochytrids at -80°C with 10% glycerol, the combination of 5% trehalose and 10% glycerol, and freezing in vapor-phase liquid nitrogen were found to maintain significant cell viability. The information provided in this study could be applied to cryopreservation and biotechnological applications of the economically valuable marine Labyrinthulomycetes from Thailand. [ABSTRACT FROM AUTHOR]

The species diversity of marine fungi was investigated in eastern and southern Thailand. Senescent and decaying woody substrata were collected from intertidal mangrove forests located in Trat, Prachuap Khiri Khan and Phetchaburi Provinces. A total of 99 fungal species was recorded. These included 84 Ascomycota (85%), two Basidiomycota (2%) and 13 asexual fungi (13%). The average percentage occurrence of the fungi recorded from each site ranged from 0.1% to 13.7%. Based on the percentage of samples in which a particular taxon was found, the most frequent fungi were Quintaria lignatilis (8%), Rimora mangrovei (8%) and Salsuginea ramicola (7%). The results showed that 25 species were common to all three provinces. The Shannon-Wiener diversity index, equitability species evenness index and Margalef's species richness index were the highest in Trat Province, followed by Prachuap Khiri Khan and Phetchaburi Provinces. Moreover, eight fungal species were new records for Thailand: Aniptodera salsuginosa, Etheirophora bijubata, Etheirophora blepharospora, Neptunella longirostris, Oceanitis cincinnatula, Savoryella melanospora, Sedecimiella taiwanensis and Trichocladium lignicola, and there are three new species. The results from this study provide an insight into the diversity of marine fungi present in Thai mangroves bringing the current total number to 184 species. [ABSTRACT FROM AUTHOR]

This paper documents five new saprobic marine fungi occurring on various substrata in the marine environment. Bacusphaeria nypae gen. et sp. nov. was discovered on bases of fronds of Nypa fruticans in Malaysia and phylogenetically, it belongs to the Tirisporellaceae (Tirisporellales, Diaporthomycetidae, Sordariomycetes) based on 18S and 28S rDNA. Cryptovalsa avicenniae, Ceriosporopsis minuta and Jattaea mucronata also belong to the Sordariomycetes; Cr. avicenniae was saprobic on Avicennia marina collected in Saudi Arabia, J. mucronata on intertidal decaying bark of Rhizophora mucronata while Ce. minuta was found on driftwood collected on a sandy beach in Japan. Phylogeny based on 18S and 28S rDNA placed Cr. avicenniae with other Cryptovalsa species in the Diatrypaceae. Jattaea mucronata groups well in the Calosphaeriales and is closely related to J. algeriensis based on a phylogeny using ITS and 28S rRNA and RPB2 genes. Aegeanispora elanii gen. et sp. nov. is an asexual fungus which produces pycnidia on decaying driftwood collected in the Aegean Sea. Combined 18S and 28S rDNA phylogenetic analyses suggest that it is a member of the Pleosporales, Dothideomycetes. Ceriosporopsis minuta resembles C. capillacea with its tubular, long polar appendages of ascospores but dimensions of ascomata and ascospores for the former species are considerably smaller. Ceriosporopsis is considered the best genus to accommodate C. minuta without support from sequence data. Sammeyersia is established as a new genus to accommodate Lulworthia grandispora, a species unrelated to Lulworthia fucicola, the type species. The diagnostic characteristic for the genus is a melanized region at the base of the neck of the ascomata. [ABSTRACT FROM AUTHOR]

Trematosphaeriaceae fam. nov. is introduced to accommodate the genera Falciformispora, Halomassarina and Trematosphaeria. The main distinguishing characters of the family are medium-sized rounded ascomata with a papillate ostiole, a relatively wide, coriaceous peridium, cellular pseudoparaphyses and cylindro-clavate asci. The ascospores are two-celled or many celled, hyaline or brown. Phylogenetic analysis inferred from combined nuclear SSU and LSU rRNA and translation elongation factor 1-alpha (TEF-1-alpha) and second largest subunit of RNA polymerase (RPB2) datasets show that these genera form a strongly supported cluster within the Pleosporales. The type species of each genus is illustrated and briefly discussed. Asteromassaria pulchra has been included in the family in previous publications; however, since the type of the genus (A. macrospora) was not included in the phylogenetic analysis, the familial placement cannot be confirmed. Furthermore Asteromassaria pulchra did not cluster in Trematosphaeriaceae in the analysis presented in this paper. [ABSTRACT FROM AUTHOR]

The taxonomic placement of freshwater and marine Savoryella species has been widely debated, and the genus has been tentatively assigned to various orders in the Sordariomycetes. The genus is characterized as possessing paraphyses that deliquesce early, elongate, clavate to cylindrical asci with a poorly developed apical ring and versicolored, three-septate ascospores. We performed two combined phylogenetic analyses of different genes: (i) partial small subunit rRNA (SSU), large subunit rRNA (LSU), DNA-dependent RNA polymerase II largest subunit (rpb2) dataset and (ii) SSU rDNA, LSU rDNA, DNA-dependent RNA polymerase II largest subunit (rpb1 and rpb2), translation elongation factor 1-alpha (tef1), the 5.8S ribosomal DNA (5.8S rDNA) dataset. Our results indicate that Savoryella species formed a monophyletic group within the Sordariomycetes but showed no affinity to the Hypocreales, Halosphaeriales (now Microascales), Sordariales and Xylariales, despite earlier assignments to these orders. Savoryella, Ascotaiwania and Ascothailandia (and its anamorph, Canalisporium) formed a new lineage that has invaded both marine and freshwater habitats, indicating that these genera share a common ancestor and are closely related. Because they show no clear relationship with any named order we erect a new order Savoryellales in the subclass Hypocreomycetidae, Sordariomycetes. The genera Savoryella and Ascothailandia are monophyletic, while the position of Ascotaiwania is unresolved. All three genera are phylogenetically related and form a distinct clade similar to the unclassified group of marine ascomycetes comprising the genera Swampomyces, Torpedospora and Juncigera (TBM clade: Torpedospora/Bertia/ Melanospora) in the Hypocreomycetidae incertae sedis. [ABSTRACT FROM AUTHOR]