Publications by authors named "Ka-Lai Pang"

32 Publications

Natural polyketide 6-pentyl-2-pyrone-2-one and its synthetic analogues efficiently prevent marine biofouling.

Biofouling 2021 Apr 18:1-10. Epub 2021 Apr 18.

Department of Marine Biotechnology, National Sun Yat-sen University, Kaohsiung, Taiwan, ROC.

Biofouling is a widespread phenomenon in oceans worldwide. With increasing human development and activities in open and coastal waters, and due to the environmental impact of AF organotins and copper-based paint, the demand for nontoxic antifouling (AF) paints is increasing. Various bioassays for antimicrobial activity, anti-biofilm formation and anti-barnacle settlement were established to evaluate the possibility of using marine natural products as AF agents. A series of natural products, isolated from the marine-derived fungi and , were evaluated for their AF activity. One pyrone-type compound () demonstrated significant inhibitory activities toward barnacle cyprid settlement. Furthermore, a series of pyrone analogues (-) were synthesized, and their bioactivities were evaluated in the established systems. The results showed that compounds and exhibited a broad spectrum of bioactivities, such as anti-barnacle settlement, anti-biofilm formation and antimicrobial activities.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/08927014.2021.1890043DOI Listing
April 2021

Salinity, pH and temperature growth ranges of isolates suggest their physiological adaptations to mangrove environments.

Mycology 2020 Jan 14;11(3):256-262. Epub 2020 Jan 14.

Institute of Marine Biology and Centre of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan.

Species of are early colonisers of fallen mangrove leaves in the tropics but recently found commonly in temperate areas. In mangrove habitats, temperature and salinity change rapidly daily (high/low tide) and seasonally (summer/winter, rainy/dry seasons). Mangrove organisms have to develop adaptive strategies to thrive in such a physiologically challenging environment. In this study, growth of three isolates of and two isolates of was tested under combined effects of 3 temperatures (15°C, 25°C, 37°C), 3 pHs (6, 7, 8) and 4 salinities (4 ‰, 8 ‰, 16 ‰, 32 ‰). No/little growth was observed at 37°C and growth saturation occurred earlier at 25°C than at 15°C. The log phase of growth was steeper at pH 6 than pH 7 and 8. Temperature and pH were found to exert a greater effect on growth than salinity. Generally, a reduction of growth rate was observed at pH 8 and 15°C. Increase in salinity caused a slight decrease in growth, most noticeable at 32 ‰. The wide growth ranges of temperature, salinity and pH of isolates suggest that they are well adapted to the physical and chemical conditions of mangrove habitats.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/21501203.2020.1714768DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7534344PMC
January 2020

Marine fungi of the Baltic Sea.

Mycology 2020 Mar 12;11(3):195-213. Epub 2020 Mar 12.

Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia.

Vast parts of the Baltic Sea have been mycologically neglected and are still awaiting exploration. Here we summarise earlier records of marine fungi from the Baltic, supplementing them with discoveries from fieldwork in Sweden in 2019. Although marine fungal diversity is clearly attenuated in the brackish water of the Baltic Sea, a substantial number has still been discovered. Here we list 77 species from the Baltic Sea, whereas after a critical assessment a further 18 species have been excluded as records of marine fungi. The species have mainly been identified by their morphological features, supplemented by DNA-based diagnostics. Most of the species have their main distributions in temperate areas of the Atlantic Ocean. Some of the Baltic species discovered here represent far disjunctions to tropical waters while only a very few are until now only recorded for the Baltic Sea. In this paper two species belong in Basidiomycota, while the most ascomyceteous speciose classes are Sordariomycetes (with 42 species) and Dothideomycetes (24). Halosphaeriaceae is the most speciose family in marine habitats, as also in the Baltic Sea, represented here by 29 species. Three species are new to Europe, and in addition 13 to the Baltic Sea and 13 to Sweden.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/21501203.2020.1729886DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7534365PMC
March 2020

Highly Oxygenated Constituents from a Marine Alga-Derived Fungus NTU967.

Mar Drugs 2020 Jun 6;18(6). Epub 2020 Jun 6.

Institute of Fisheries Science, National Taiwan University, Taipei 10617, Taiwan.

Agar-based disc diffusion antimicrobial assay has shown that the ethyl acetate extract of the fermented broth of NTU967 isolated from exhibited significant antimicrobial activity in our preliminary screening of bioactive fungal strains. Therefore, column chromatography of the active principles from liquid- and solid-state fermented products of the fungal strain was carried out, and which had led to isolation of eleven compounds. Their structures were determined by spectral analysis to be seven new highly oxygenated polyketides, namely aspergilsmins A-G (-), along with previously reported patulin, deoxytryptoquivaline, tryptoquivaline and quinadoline B. Among these, aspergilsmin C () and patulin displayed promising anticancer activities against human hepatocellular carcinoma SK-Hep-1 cells and prostate cancer PC-3 cells with IC values between 2.7-7.3 μM. Furthermore, aspergilsmin C () and patulin exhibited significant anti-angiogenic functions by impeding cell growth and tube formation of human endothelial progenitor cells without any cytotoxicity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/md18060303DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7374281PMC
June 2020

Growth study under combined effects of temperature, pH and salinity and transcriptome analysis revealed adaptations of Aspergillus terreus NTOU4989 to the extreme conditions at Kueishan Island Hydrothermal Vent Field, Taiwan.

PLoS One 2020 26;15(5):e0233621. Epub 2020 May 26.

Institute of Marine Biology and Centre of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan.

A high diversity of fungi was discovered on various substrates collected at the marine shallow-water Kueishan Island Hydrothermal Vent Field, Taiwan, using culture and metabarcoding methods but whether these fungi can grow and play an active role in such an extreme environment is unknown. We investigated the combined effects of different salinity, temperature and pH on growth of ten fungi (in the genera Aspergillus, Penicillium, Fodinomyces, Microascus, Trichoderma, Verticillium) isolated from the sediment and the vent crab Xenograpsus testudinatus. The growth responses of the tested fungi could be referred to three groups: (1) wide pH, salinity and temperature ranges, (2) salinity-dependent and temperature-sensitive, and (3) temperature-tolerant. Aspergillus terreus NTOU4989 was the only fungus which showed growth at 45 °C, pH 3 and 30 ‰ salinity, and might be active near the vents. We also carried out a transcriptome analysis to understand the molecular adaptations of A. terreus NTOU4989 under these extreme conditions. Data revealed that stress-related genes were differentially expressed at high temperature (45 °C); for instance, mannitol biosynthetic genes were up-regulated while glutathione S-transferase and amino acid oxidase genes down-regulated in response to high temperature. On the other hand, hydrogen ion transmembrane transport genes and phenylalanine ammonia lyase were up-regulated while pH-response transcription factor was down-regulated at pH 3, a relative acidic environment. However, genes related to salt tolerance, such as glycerol lipid metabolism and mitogen-activated protein kinase, were up-regulated in both conditions, possibly related to maintaining water homeostasis. The results of this study revealed the genetic evidence of adaptation in A. terreus NTOU4989 to changes of environmental conditions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0233621PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7250430PMC
August 2020

Insights into fungal diversity of a shallow-water hydrothermal vent field at Kueishan Island, Taiwan by culture-based and metabarcoding analyses.

PLoS One 2019 30;14(12):e0226616. Epub 2019 Dec 30.

Institute of Marine Biology and Centre of Excellence of the Oceans, National Taiwan Ocean University, Keelung, Taiwan.

This paper reports the diversity of fungi associated with substrates collected at a shallow hydrothermal vent field at Kueishan Island, Taiwan, using both culture-based and metabarcoding methods. Culture of fungi from yellow sediment (with visible sulfur granules), black sediment (no visible sulfur granules), the vent crab Xenograpsus testudinatus, seawater and, animal egg samples resulted in a total of 94 isolates. Species identification based on the internal transcribed spacer regions of the rDNA revealed that the yellow sediment samples had the highest species richness with 25 species, followed by the black sediment (23) and the crab (13). The Ascomycota was dominant over the Basidiomycota; the dominant orders were Agaricales, Capnodiales, Eurotiales, Hypocreales, Pleosporales, Polyporales and Xylariales. Hortaea werneckii was the only common fungus isolated from the crab, seawater, yellow and black sediment samples. The metabarcoding analysis amplifying a small fragment of the rDNA (from 18S to 5.8S) recovered 7-27 species from the black sediment and 12-27 species from the yellow sediment samples and all species belonged to the Ascomycota and the Basidiomycota. In the yellow sediments, the dominant order was Pleosporales and this order was also dominant in the black sediment together with Sporidiobolales. Based on the results from both methods, 54 and 49 species were found in the black and yellow sediments, respectively. Overall, a higher proportion of Ascomycota (~70%) over Basidiomycota was recovered in the yellow sediment and the two phyla were equally abundant in the black sediment. The top five dominant fungal orders in descending order based on species richness were Pleosporales>Eurotiales>Polyporales>Hypocreales>Capnodiales in the black sediment samples, and Polyporales>Pleosporales>Eurotiales>Capnodiales>Hypocreales in the yellow sediment samples. This study is the first to observe a high diversity of fungi associated with various substrates at a marine shallow water hydrothermal vent ecosystem. While some fungi found in this study were terrestrial species and their airborne spores might have been deposited into the marine sediment, several pathogenic fungi of animals, including Acremonium spp., Aspergillus spp., Fusarium spp., Malassezia spp., Hortaea werneckii, Parengyodontium album, and Westerdykella dispersa, were recovered suggesting that these fungi may be able to cause diseases of marine animals.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0226616PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6936883PMC
April 2020

Fucoxanthin, a Marine Xanthophyll Isolated From ND-8: Preventive Anti-Inflammatory Effect in a Mouse Model of Sepsis.

Front Pharmacol 2019 28;10:906. Epub 2019 Aug 28.

The Public Service Platform for Industrialization Development Technology of Marine Biological Medicine and Product of State Oceanic Administration, Center of Engineering Technology Research for Microalgae Germplasm Improvement of Fujian, Southern Institute of Oceanography, Fujian Normal University, Fuzhou, China.

Fucoxanthin (FX), a xanthophyll pigment which occurs in marine brown algae with remarkable biological properties, has been proven to be safe for consumption by animals. Although FX has various pharmacological effects including anti-inflammatory, anti-tumor, anti-obesity, antioxidant, anti-diabetic, anti-malarial, and anti-lipid, protective effect against sepsis has not been reported. In this study, we aimed at evaluation the efficacy of the FX in a model of sepsis mouse. FX was successfully isolated from ND-8 for the first time. The FX was identified by thin-layer chromatography (TLC), high-performance liquid chromatography-mass spectrometry (HPLC-MS), and nuclear magnetic resonance (NMR). Animals were randomly divided into 9 groups, including Sham group (mouse received an intraperitoneal injection of normal saline 1.0 ml/kg), FX-treated (0.1-1.0 ml/kg), Lipopolysaccharide (LPS)-treated (20 mg/kg), FX+LPS-treated (0.1-10.0 mg/kg and 20 mg/kg, respectively), and urinastatin groups (10 U/kg). Nuclear factor (NF)-κB activation could be potential treatment for sepsis. NF-κB signaling components were determined by western-blotting. IL-6, IL-1β, TNF-α production, and NF-κB activation were evaluated by ELISA and immunofluorescent staining . FX was found to decrease the expression of inflammatory cytokines including IL-6, IL-1β, and TNF-α, in a prophylactic manner in the LPS-induced sepsis mouse model. Meanwhile, FX significantly inhibits phosphorylation of the NF-κB signaling pathway induced by LPS at the cellular level and reduces the nuclear translocation of NF-κB. The IC for suppressing the expression of NF-κB was 11.08 ± 0.78 μM in the THP1-Lucia™ NF-κB cells. Furthermore, FX also inhibits the expression of inflammatory factors in a dose-dependent manner with the IC inhibition of IL-6 production was 2.19 ± 0.70 μM in Raw267.4 macrophage cells. It is likely that the molecules with the ability of targeting NF-κB activation and inflammasome assembly, such as fucoxanthin, are interesting subjects to be used for treating sepsis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fphar.2019.00906DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6722224PMC
August 2019

A highly diverse fungal community associated with leaves of the mangrove plant var. revealed by isolation and metabarcoding analyses.

PeerJ 2019 9;7:e7293. Epub 2019 Jul 9.

Institute of Marine Biology and Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan.

A high diversity of culturable foliar endophytic fungi is known from various mangrove plants, and the core taxa include species from , , , , , among others. Since a small fraction of fungi is able to grow in culture, this study investigated the diversity of fungi associated with leaves of var. using both isolation and metabarcoding approaches. A total of 203 isolates were cultured from surface-sterilized leaves, representing 47 different fungal species: 30 species from the winter samples (104 isolates), and 26 species from the summer samples (99 isolates). Ascomycota was dominant in both types of leaf samples, while Basidiomycota was isolated only from the summer samples. (10.58%, percentage of occurrence), sp. 3 (7.69%) and sp. (7.69%) were dominant in the winter samples; (13.13%), (10.10%) and sp. 1 (9.09%) in the summer samples. Overall, (6.90%), (6.40%) and sp. (6.40%) had the highest overall percentage of occurrence. In the metabarcoding analysis, a total of 111 operational taxonomic units (OTUs) were identified from 17 leaf samples: 96 OTUs from the winter and 70 OTUs from the summer samples. Sequences belonging to Ascomycota and Basidiomycota were detected in both samples but the former phylum was dominant over the latter. Based on read abundance, taxa having the highest percentage of occurrence included sp. (3.46%), (2.56%) and (1.41%) in the winter leaves, and sp. (10.72%), sp. (7.90%), (3.45%) and (3.21%) in the summer leaves. These latter four species also had the highest overall percentage of occurrence. Combining the results from both methods, a high diversity of fungi (at least 110 species) was found associated with leaves of var. . Many of the fungi identified were plant pathogens and may eventually cause diseases in the host.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.7717/peerj.7293DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6625500PMC
July 2019

Chimeric 6-methylsalicylic acid synthase with domains of acyl carrier protein and methyltransferase from Pseudallescheria boydii shows novel biosynthetic activity.

Microb Biotechnol 2019 09 14;12(5):920-931. Epub 2019 Jun 14.

Department of Bioscience and Biotechnology, Center of Excellence for the Oceans, National Taiwan Ocean University, No. 2 Pei-Ning Road, Keelung, 20224, Taiwan.

Polyketides are important secondary metabolites, many of which exhibit potent pharmacological applications. Biosynthesis of polyketides is carried out by a single polyketide synthase (PKS) or multiple PKSs in successive elongations of enzyme-bound intermediates related to fatty acid biosynthesis. The polyketide gene PKS306 from Pseudallescheria boydii NTOU2362 containing domains of ketosynthase (KS), acyltransferase (AT), dehydratase (DH), acyl carrier protein (ACP) and methyltransferase (MT) was cloned in an attempt to produce novel chemical compounds, and this PKS harbouring green fluorescent protein (GFP) was expressed in Saccharomyces cerevisiae. Although fluorescence of GFP and fusion protein analysed by anti-GFP antibody were observed, no novel compound was detected. 6-methylsalicylic acid synthase (6MSAS) was then used as a template and engineered with PKS306 by combinatorial fusion. The chimeric PKS containing domains of KS, AT, DH and ketoreductase (KR) from 6MSAS with ACP and MT from PKS306 demonstrated biosynthesis of a novel compound. The compound was identified with a deduced chemical formula of C H O , and the chemical structure was named as 2-hydroxy-2-(propan-2-yl) cyclobutane-1,3-dione. The novel compound synthesized by the chimeric PKS in this study demonstrates the feasibility of combinatorial fusion of PKS genes to produce novel polyketides.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/1751-7915.13445DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6681407PMC
September 2019

Potential roles of marine fungi in the decomposition process of standing stems and leaves of .

Mycologia 2019 May-Jun;111(3):371-383. Epub 2019 May 16.

d Institute of Marine Biology and Centre of Excellence for the Oceans, National Taiwan Ocean University, 2 Pei-Ning Road , Keelung 20224 , Taiwan , Republic of China.

Fungal communities inhabiting live, senescent, and decaying leaf sheaths, stems, and leaf blades of standing plants of in two Portuguese salt marshes were assessed by morphological identification of fruiting structures and sequence-based identification based on polymerase chain reaction (PCR)-cloning analysis of the internal transcribed spacer (ITS) rDNA. The molecular method enabled identification of infrequent ascomycetes and basidiomycetes (filamentous and yeasts) and the asexual morph of and . The occurrence and ecological role of the most frequent fungi on different substrates seem to depend on the phase of plant life cycle, and specifically on the availability and microenvironmental conditions of each plant substrate. Specifically, , and sp. 1 were involved in the decay of lower-middle culms, of middle culms and leaves, , and sp. 1 of middle-upper leaves, and sp. I of upper leaves of early-decaying plants. The presence of these fungi on live vegetative structures suggests that they might begin the colonization process as endophytes, gaining a competitive advantage over the other saprobic fungi on the plants.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/00275514.2019.1571380DOI Listing
April 2020

Antimicrobial and iNOS inhibitory activities of the endophytic fungi isolated from the mangrove plant Acanthus ilicifolius var. xiamenensis.

Bot Stud 2019 Mar 12;60(1). Epub 2019 Mar 12.

Institute of Fisheries Science, National Taiwan University, Taipei, 10617, Taiwan.

Background: Acanthus ilicifolius var. xiamenensis (Acanthaceae) is an old world mangrove species and has long been used as a folk remedy for treating various ailments in traditional medicine. The nature source of A. ilicifolius var. xiamenensis is now in short supply because of the urban development and habitat destruction. To better utilize this resource, biodiversity and bioactivity of endophytic fungi isolated from A. ilicifolius var. xiamenensis were investigated.

Results: A total of 168 fungal isolates were cultured from leaves and stems of the mangrove plant collected in January (winter) and July (summer) 2014 at Kinmen County, Taiwan. Spent culture extract of 28 isolates were found to have bioactivities against one of the following pathogenic microorganisms: the bacteria Bacillus subtilis, Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative) and the fungi Candida albicans and Cryptococcus neoformans. These positive extracts were mostly active against the Gram-positive bacteria and C. albicans. Corynespora cassiicola NTOU4889 and Xylaria sp. NTOU4900 inhibited growth of all 3 test bacteria whereas Phellinus noxius NTOU4917 inhibited both test fungi. A further anti-inflammatory study of culture extracts of these 28 isolates revealed that extracts with a high iNOS inhibition caused a low viability of cells, and those with a low iNOS inhibition had a high cell viability. Three extracts showed low cytotoxicity (i.e. > 100% cell viability) and high iNOS inhibition (< 15% of NO production) of cells and they were Phoma sp. 2 NTOU4338, Nodulisporium sp. NTOU4868 and Guignardia sp. NTOU4871.

Conclusion: These results indicate that the endophytic fungi associated with A. ilicifolius var. xiamenensis can be a potential source of novel natural active substance.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s40529-019-0252-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6419792PMC
March 2019

The Neglected Marine Fungi, , and Their Isolation for Natural Products' Discovery.

Mar Drugs 2019 Jan 10;17(1). Epub 2019 Jan 10.

Institute of Marine Biology and Centre of Excellence for the Oceans, National Taiwan Ocean University, 20224 Keelung, Taiwan.

Despite the rapid development of molecular techniques relevant for natural product research, culture isolates remain the primary source from which natural products chemists discover and obtain new molecules from microbial sources. Techniques for obtaining and identifying microbial isolates (such as filamentous fungi) are thus of crucial importance for a successful natural products' discovery program. This review is presented as a "best-practices guide" to the collection and isolation of marine fungi for natural products research. Many of these practices are proven techniques used by mycologists for the isolation of a broad diversity of fungi, while others, such as the construction of marine baiting stations and the collection and processing of sea foam using dilution to extinction plating techniques, are methodological adaptations for specialized use in marine/aquatic environments. To this day, marine fungi, , remain one of the few underexplored resources of natural products. Cultivability is one of the main limitations hindering the discovery of natural products from marine fungi. Through encouraged collaboration with marine mycologists and the sharing of historically proven mycological practices for the isolation of marine fungi, our goal is to provide natural products chemists with the necessary tools to explore this resource in-depth and discover new and potentially novel natural products.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/md17010042DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6356354PMC
January 2019

Does Osmotic Stress Affect Natural Product Expression in Fungi?

Mar Drugs 2017 Aug 13;15(8). Epub 2017 Aug 13.

Department of Chemistry, University of Prince Edward Island, 550 University Avenue, Charlottetown, PE C1A 4P3, Canada.

The discovery of new natural products from fungi isolated from the marine environment has increased dramatically over the last few decades, leading to the identification of over 1000 new metabolites. However, most of the reported marine-derived species appear to be terrestrial in origin yet at the same time, facultatively halo- or osmotolerant. An unanswered question regarding the apparent chemical productivity of marine-derived fungi is whether the common practice of fermenting strains in seawater contributes to enhanced secondary metabolism? To answer this question, a terrestrial isolate of was fermented in osmotic and saline stress conditions in parallel across multiple sites. The ex-type strain of was obtained from three different culture collections. Site-to-site variations in metabolite expression were observed, suggesting that subculturing of the same strain and subtle variations in experimental protocols can have pronounced effects upon metabolite expression. Replicated experiments at individual sites indicated that secondary metabolite production was divergent between osmotic and saline treatments. Titers of some metabolites increased or decreased in response to increasing osmolite (salt or glycerol) concentrations. Furthermore, in some cases, the expression of some secondary metabolites in relation to osmotic and saline stress was attributed to specific sources of the ex-type strains.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/md15080254DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5577608PMC
August 2017

Hirsutane-Type Sesquiterpenes with Inhibitory Activity of Microglial Nitric Oxide Production from the Red Alga-Derived Fungus Chondrostereum sp. NTOU4196.

J Nat Prod 2017 05 17;80(5):1615-1622. Epub 2017 May 17.

Institute of Fisheries Science, National Taiwan University , Taipei 10617, Taiwan.

The marine red alga Pterocladiella capillacea is an economic alga for the food industry in Taiwan, and its associated highly diversified fungi have not been investigated meticulously thus far. The EtOAc extract of the fermented broth of Chondrostereum sp. NTOU4196, a fungal strain isolated from P. capillacea, was found to exhibit significant nitric oxide (NO) production inhibitory activity in lipopolysaccharide-activated murine RAW 264.7 cells at a concentration of 100 μg/mL in the preliminary screening. Therefore, separation of the active principles from the fermented broths was performed, and that has led to the isolation of eight new 5,5,5-tricyclic hirsutane-type sesquiterpenes, namely, chondroterpenes A-H (1-8), together with seven known analogues. They were identified by analyses of spectroscopic data and comparison with literature values. Among the new isolates, chondroterpene A (1) exhibited more significant NO production inhibitory activity in murine BV-2 microglial cells, and of all the isolated compounds, hirsutanol A (9) exerted limited cytotoxic effects and the most potent inhibitory activity on NO production.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.jnatprod.7b00196DOI Listing
May 2017

Angiogenesis Inhibitors and Anti-Inflammatory Agents from Phoma sp. NTOU4195.

J Nat Prod 2016 Dec 15;79(12):2983-2990. Epub 2016 Dec 15.

Institute of Fisheries Science, National Taiwan University , Taipei 10617, Taiwan.

Seven new polyketides, phomaketides A-E (1-5) and pseurotins A (6) and G (7), along with the known compounds FR-111142, pseurotins A, A, A, D, and F, 14-norpseurotin A, α-carbonylcarbene, tyrosol, cyclo(-l-Pro-l-Leu), and cyclo(-l-Pro-l-Phe), were purified from the fermentation broth and mycelium of the endophytic fungal strain Phoma sp. NTOU4195 isolated from the marine red alga Pterocladiella capillacea. The structures were established through interpretation of spectroscopic data. The antiangiogenic and anti-inflammatory effects of 1-7 and related analogues were evaluated using human endothelial progenitor cells (EPCs) and lipopolysaccharide (LPS)-activated murine macrophage RAW264.7 cells, respectively. Of the compounds tested, compound 1 exhibited the most potent antiangiogenic activity by suppressing the tube formation of EPCs with an IC of 8.1 μM, and compound 3 showed the most selective inhibitory activity of LPS-induced NO production in RAW264.7 macrophages with an IC value of 8.8 μM.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.jnatprod.6b00407DOI Listing
December 2016

Recommendations for competing sexual-asexually typified generic names in Sordariomycetes (except Diaporthales, Hypocreales, and Magnaporthales).

IMA Fungus 2016 Jun 8;7(1):131-53. Epub 2016 Jun 8.

Center of Excellence in Fungal Research, School of Science, Mae Fah Luang University, Chiang Rai 57100, Thailand.

With the advance to one scientific name for each fungal species, the generic names in the class Sordariomycetes typified by sexual and asexual morphs are evaluated based on their type species to determine if they compete with each other for use or protection. Recommendations are made for which of the competing generic names should be used based on criteria such as priority, number of potential names changes, and frequency of use. Some recommendations for well-known genera include Arthrinium over Apiospora, Colletotrichum over Glomerella, Menispora over Zignoëlla, Microdochium over Monographella, Nigrospora over Khuskia, and Plectosphaerella over Plectosporium. All competing generic names are listed in a table of recommended names along with the required action. If priority is not accorded to sexually typified generic names after 2017, only four names would require formal protection: Chaetosphaerella over Oedemium, Diatrype over Libertella, Microdochium over Monographella, and Phaeoacremonium over Romellia and Togninia. Concerning species in the recommended genera, one replacement name (Xylaria benjaminii nom. nov.) is introduced, and the following new combinations are made: Arthrinium sinense, Chloridium caesium, C. chloroconium, C. gonytrichii, Corollospora marina, C. parvula, C. ramulosa, Juncigena fruticosae, Melanospora simplex, Seimatosporium massarina, Sporoschisma daemonoropis, S. taitense, Torpedospora mangrovei, Xylaria penicilliopsis, and X. termiticola combs. nov.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.5598/imafungus.2016.07.01.08DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4941682PMC
June 2016

Diversity and Ecological Characterization of Sporulating Higher Filamentous Marine Fungi Associated with Spartina maritima (Curtis) Fernald in Two Portuguese Salt Marshes.

Microb Ecol 2015 Oct 8;70(3):612-33. Epub 2015 Apr 8.

Centre for Ecology, Evolution and Environmental Changes (Ce3C), Faculty of Sciences of University of Lisbon, Edifício C2, 5° Piso, Campo Grande, 1749-016, Lisbon, Portugal.

Fungal communities associated with early stages of decomposition of Spartina maritima (Curtis) Fernald were assessed in two geographically distinct salt marshes in Portugal by direct observation of fungal sporulating structures. Twenty-three fungal taxa were identified from 390 plant samples, 11 of which were common to both study sites. Natantispora retorquens, Byssothecium obiones, Phaeosphaeria spartinicola, Phoma sp. 1 and Stagonospora sp. were the most frequent fungal taxa in the studied communities. The fungal species Anthostomella spissitecta, Camarosporium roumeguerii, Coniothyrium obiones, Decorospora gaudefroyi, Halosarpheia trullifera, Leptosphaeria marina and Stagonospora haliclysta were recorded for the first time on S. maritima plants; with the exception of C. roumeguerii and L. marina, all of these species were also new records for Portugal. The differences between species composition of the communities associated with S. maritima were attributed to differences in abiotic conditions of the salt marshes. Although the fungal taxa were distributed differently along the host plants, common species to both fungal communities were found on the same relative position, e.g. B. obiones, Lulworthia sp. and N. retorquens occurred on the basal plant portions, Buergenerula spartinae, Dictyosporium pelagicum and Phoma sp. 1 on the middle plant portions and P. spartinicola and Stagonospora sp. on the top plant portions. The distinct vertical distribution patterns reflected species-specific salinity requirements and flooding tolerance, but specially substrate preferences. The most frequent fungi in both communities also exhibited wider distribution ranges and produced a higher number of fruiting structures, suggesting a more active key role in the decay process of S. maritima.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00248-015-0600-0DOI Listing
October 2015

Miniaturized Cultivation of Microbiota for Antimalarial Drug Discovery.

Med Res Rev 2016 Jan 26;36(1):144-68. Epub 2014 Dec 26.

Department of Chemistry, University of South Florida, Tampa, Florida, 33620, USA.

The ongoing search for effective antiplasmodial agents remains essential in the fight against malaria worldwide. Emerging parasitic drug resistance places an urgent need to explore chemotherapies with novel structures and mechanisms of action. Natural products have historically provided effective antimalarial drug scaffolds. In an effort to search nature's chemical potential for antiplasmodial agents, unconventionally sourced organisms coupled with innovative cultivation techniques were utilized. Approximately 60,000 niche microbes from various habitats (slow-growing terrestrial fungi, Antarctic microbes, and mangrove endophytes) were cultivated on a small-scale, extracted, and used in high-throughput screening to determine antimalarial activity. About 1% of crude extracts were considered active and 6% partially active (≥ 67% inhibition at 5 and 50 μg/mL, respectively). Active extracts (685) were cultivated on a large-scale, fractionated, and screened for both antimalarial activity and cytotoxicity. High interest fractions (397) with an IC50 < 1.11 μg/mL were identified and subjected to chromatographic separation for compound characterization and dereplication. Identifying active compounds with nanomolar antimalarial activity coupled with a selectivity index tenfold higher was accomplished with two of the 52 compounds isolated. This microscale, high-throughput screening project for antiplasmodial agents is discussed in the context of current natural product drug discovery efforts.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/med.21335DOI Listing
January 2016

Production of arachidonic and eicosapentaenoic acids by the marine oomycete Halophytophthora.

Mar Biotechnol (NY) 2015 Apr 15;17(2):121-9. Epub 2014 Aug 15.

Institute of Marine Biology and Center of Excellence for the Oceans, National Taiwan Ocean University, 2 Pei-Ning Road, Keelung, 20224, Taiwan, Republic of China,

Polyunsaturated fatty acids (PUFAs) are fatty acids with more than one double bond in the chemical structure. Arachidonic acid (ARA, 20:4 (n-6)) and eicosapentaenoic acid (EPA, 22:5 (n-3)) are common PUFAs with beneficial health effects. Marine fish and meat are the main sources of omega-3 and omega-6 fatty acids in human's diet, respectively. In particular, there is a general decline in fish catch, implicating the need for an alternative source of omega-3 fatty acids. Previous studies have examined the production of polyunsaturated fatty acids including ARA and EPA by various microorganisms, including microalgae, fungi, and thraustochytrids. In this study, the production of ARA and EPA by 10 isolates of four estuarine Halophytophthora species (Halophytophthora avicenniae, Halophytophthora polymorphica, Halophytophthora vesicula, and Halophytophthora spinosa var. spinosa) cultured from fallen mangrove leaves in Taiwan was examined. The yield of ARA ranged from 0.004 to 0.052 g/L with the highest yield of ARA obtained from H. spinosa var. spinosa IMB162, but no or a very low level of EPA was produced by IMB162. For EPA production by Halophytophthora spp., the yield ranged from 0 to 0.047 g/L. Percentage of ARA in total fatty acid ranged between 7.16 and 25.02%. One-way ANOVA analysis using Tukey Test (p ≥ 0.05) suggested that there is significant difference in the percentage of EPA in total fatty acid produced by the isolates, which ranged from 0.01 to 18.42%. BODIPY 505/515 fluorescent staining suggests that lipid bodies were evenly distributed in the mycelia of Halophytophthora species.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10126-014-9600-1DOI Listing
April 2015

High fungal diversity and abundance recovered in the deep-sea sediments of the Pacific Ocean.

Microb Ecol 2014 Nov 9;68(4):688-98. Epub 2014 Jul 9.

School of Life Sciences, Xiamen University, Xiamen, 361005, People's Republic of China.

Knowledge about the presence and ecological significance of bacteria and archaea in the deep-sea environments has been well recognized, but the eukaryotic microorganisms, such as fungi, have rarely been reported. The present study investigated the composition and abundance of fungal community in the deep-sea sediments of the Pacific Ocean. In this study, a total of 1,947 internal transcribed spacer (ITS) regions of fungal rRNA gene clones were recovered from five sediment samples at the Pacific Ocean (water depths ranging from 5,017 to 6,986 m) using three different PCR primer sets. There were 16, 17, and 15 different operational taxonomic units (OTUs) identified from fungal-universal, Ascomycota-, and Basidiomycota-specific clone libraries, respectively. Majority of the recovered sequences belonged to diverse phylotypes of Ascomycota (25 phylotypes) and Basidiomycota (18 phylotypes). The multiple primer approach totally recovered 27 phylotypes which showed low similarities (≤97 %) with available fungal sequences in the GenBank, suggesting possible new fungal taxa occurring in the deep-sea environments or belonging to taxa not represented in the GenBank. Our results also recovered high fungal LSU rRNA gene copy numbers (3.52 × 10(6) to 5.23 × 10(7)copies/g wet sediment) from the Pacific Ocean sediment samples, suggesting that the fungi might be involved in important ecological functions in the deep-sea environments.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00248-014-0448-8DOI Listing
November 2014

Screening mangrove endophytic fungi for antimalarial natural products.

Mar Drugs 2013 Dec 12;11(12):5036-50. Epub 2013 Dec 12.

Department of Chemistry, University of South Florida, 4202 E. Fowler, CHE 205, Tampa, FL 33620, USA.

We conducted a screening campaign to investigate fungi as a source for new antimalarial compounds. A subset of our fungal collection comprising Chinese mangrove endophytes provided over 5000 lipophilic extracts. We developed an accelerated discovery program based on small-scale cultivation for crude extract screening and a high-throughput malaria assay. Criteria for hits were developed and high priority hits were subjected to scale-up cultivation. Extracts from large scale cultivation were fractionated and these fractions subjected to both in vitro malaria and cytotoxicity screening. Criteria for advancing fractions to purification were developed, including the introduction of a selectivity index and by dereplication of known metabolites. From the Chinese mangrove endophytes, four new compounds (14-16, 18) were isolated including a new dimeric tetrahydroxanthone, dicerandrol D (14), which was found to display the most favorable bioactivity profile.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/md11125036DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3877901PMC
December 2013

Polyketides from the littoral plant associated fungus Pseudallescheria boydii.

J Nat Prod 2013 Sep 21;76(9):1796-800. Epub 2013 Aug 21.

School of Pharmacy, Taipei Medical University , Taipei, Taiwan 110.

Four previously unreported chemical entities, boydone A (1), boydone B (2), botryorhodine F (3), and botryorhodine G (4), along with five known compounds, fusidilactone A (5), (R)-(-)-mevalonolactone (6), (R)-(-)-lactic acid (7), ovalicin (8), and botryorhodine C (9), were isolated from the ethyl acetate extracts of the fermented broths of the fungal strain Pseudallescheria boydii NTOU2362. The structures of 1-9 were characterized on the basis of their spectroscopic data analyses. The absolute configurations of 1 and 2 were established by comparison with the literature and the modified Mosher's method. The growth inhibitory activities of 1-9 against the A549 non-small-cell lung cancer cell line were evaluated, and 2 and 8 exhibited moderate to potent bioactivities with GI₅₀ values of 41.3 and 4.1 μM, respectively, in comparison with fluorouracil (GI₅₀ = 3.6 μM).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/np400192qDOI Listing
September 2013

Degradation of Phthalate Esters by Fusarium sp. DMT-5-3 and Trichosporon sp. DMI-5-1 Isolated from Mangrove Sediments.

Prog Mol Subcell Biol 2012 ;53:299-328

Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, State Oceanic Administration, 178 Daxue Road, Xiamen, 361005, PR China.

Phthalate esters (PAEs) are important industrial compounds mainly used as plasticizers to increase flexibility and softness of plastic products. PAEs are of major concern because of their widespread use, ubiquity in the environment, and endocrine-disrupting toxicity. In this study, two fungal strains, Fusarium sp. DMT-5-3 and Trichosporon sp. DMI-5-1 which had the capability to degrade dimethyl phthalate esters (DMPEs), were isolated from mangrove sediments in the Futian Nature Reserve of Shenzhen, China, by enrichment culture technique. These fungi were identified on the basis of spore morphology and molecular typing using 18S rDNA sequence. Comparative investigations on the biodegradation of three isomers of DMPEs, namely dimethyl phthalate (DMP), dimethyl isophthalate (DMI), and dimethyl terephthalate (DMT), were carried out with these two fungi. It was found that both fungi could not completely mineralize DMPEs but transform them to the respective monomethyl phthalate or phthalate acid. Biochemical degradation pathways for different DMPE isomers by both fungi were different. Both fungi could transform DMT to monomethyl terephthalate (MMT) and further to terephthalic acid (TA) by stepwise hydrolysis of two ester bonds. However, they could only carry out one-step ester hydrolysis to transform DMI to monomethyl isophthalate (MMI). Further metabolism of MMI did not proceed. Only Trichosporon sp. was able to transform DMP to monomethyl phthalate (MMP) but not Fusarium sp. The optimal pH for DMI and DMT degradation by Fusarium sp. was 6.0 and 4.5, respectively, whereas for Trichosporon sp., the optimal pH for the degradation of all the three DMPE isomers was at 6.0. These results suggest that the fungal esterases responsible for hydrolysis of the two ester bonds of PAEs are highly substrate specific.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/978-3-642-23342-5_15DOI Listing
April 2016

Morphological evaluation of peridial wall, ascus and ascospore characteristics in the delineation of genera with unfurling ascospore appendages (halosphaeriaceae).

Prog Mol Subcell Biol 2012 ;53:159-71

Institute of Marine Biology, National Taiwan Ocean University, 2 Pei-Ning Road, Keelung, 20224, Taiwan, ROC,

In the Halosphaeriaceae, taxa with unfurling ascospore appendages and related species constitute 61 species (in 21 genera). Recent phylogenetic analyses of the rRNA genes have advanced our knowledge on the relationships between genera in the family, especially the group with unfurling ascospore appendages. However, many new genera resulting from these studies lack distinctive morphological characteristics from closely related taxa. In this chapter, peridial wall layers of the ascomata and morphology of asci and ascospores are re-examined to determine if these structures offer useful information for the delineation of genera. In particular, shape parameters (aspect ratio, convexity, elongation, shape factor, sphericity, area, perimeter, diameter max, diameter mean and diameter min) of ascospores were calculated to determine if these parameters can provide extra characters for the delineation of taxa. Results suggest that peridial wall structure alone is insufficient to separate genera in the Halosphaeriaceae. Shape parameters of ascospores can provide additional characters but more taxa are required to test their efficacy. Ascus shape and length of stalk are further characters that should be calculated for taxonomical consideration. Morphology of the ascomatal wall and shape of asci and ascospores in genera with unfurling ascospore appendages in the Halosphaeriaceae are partially concordant with their phylogeny, suggesting a more thorough examination of these characters for the delineation of taxa in the family.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/978-3-642-23342-5_8DOI Listing
April 2016

Savoryellales (Hypocreomycetidae, Sordariomycetes): a novel lineage of aquatic ascomycetes inferred from multiple-gene phylogenies of the genera Ascotaiwania, Ascothailandia, and Savoryella.

Mycologia 2011 Nov-Dec;103(6):1351-71. Epub 2011 Jun 3.

Mycology Laboratory, Bioresources Technology Unit, National Center for Genetic Engineering and Biotechnology, 113 Thailand Science Park, Phaholyothin Road, Khlong 1, Khlong Luang, Pathumthani 12120, Thailand.

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.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3852/11-102DOI Listing
January 2012

Comparison of initial hydrolysis of the three dimethyl phthalate esters (DMPEs) by a basidiomycetous yeast, Trichosporon DMI-5-1, from coastal sediment.

Environ Sci Pollut Res Int 2011 Nov 31;18(9):1653-60. Epub 2011 May 31.

Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon Tong, Hong Kong, SAR, People's Republic of China.

Purpose: Dimethyl phthalate esters (DMPEs) are a group of plasticizers commonly detected in the environment with potential adverse human health impact. The degradation of DMPEs by fungal systems has been studied to a limited extent, particularly by yeasts. In this study, a basidiomycetous yeast Trichosporon DMI-5-1 capable of degrading DMPEs was obtained and the degradation pathways were investigated.

Results: A DMPE-degrading yeast was isolated from costal sediment by enrichment culture technique and was identified as Trichosporon sp. DMI-5-1 based on microscopic morphology and 18S rDNA sequence. Comparative investigations on biodegradation of three isomers of DMPEs, namely dimethyl phthalate (DMP), dimethyl isophthalate (DMI), and dimethyl terephthalate (DMT), were carried out with this yeast strain. Trichosporon sp. DMI-5-1 could not mineralize DMPEs completely but transform them to respective monomethyl phthalate or phthalic acid. Biochemical degradation pathways for the three DMPE isomers by Trichosporon sp. DMI-5-1 were apparently different. The yeast carried out one-step ester hydrolysis of DMP and DMI to respective monoesters (monomethyl phthalate and monomethyl isophthalate, respectively) and no further metabolism of these two monoesters. Meanwhile, DMT was transformed by the yeast to monomethyl terephthalate and subsequently to terephthalic acid by stepwise hydrolysis of the two ester bonds.

Conclusions: This study shows that different catalytic processes are involved in the transformation of DMPEs by the basidiomycetous yeast Trichosporon sp. DMI-5-1 and suggests that its esterases, responsible for the initial hydrolyzing the two ester bonds of DMPEs, are highly substrate specific.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11356-011-0525-1DOI Listing
November 2011

Remispora spitsbergenensis sp. nov., a marine lignicolous ascomycete from Svalbard, Norway.

Mycologia 2009 Jul-Aug;101(4):531-4

Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon Tong, Hong Kong SAR, R.O.C.

Abstract: Remispora was established for R. maritima, a fungus with globose/subglobose, lightly colored and coriaceous ascomata; deliquescing asci; ellipsoidal ascospores; and bipolar, pleomorphic ascospore appendages. Seven species currently are included in Remispora: R crispa, R. galerita, R maritima, R. minuta, R. pilleata, R. quadriremis and R stellata. Variations on ascospore appendages can be observed in Remispora. In general the appendage is exosporic in nature and comprises an amorphous, electron-transparent matrix, and a fibrous, electron-dense component. An eighth Remispora species, R. spitsbergenensis sp. nov., is described here, discovered from washed-up wood collected at the shore of Longyearbyen, Svalbard, Norway. Ascospore appendages of R. spitsbergenensis appear as fibrous strands and amorphic material under the scanning electron microscope, which are characteristic of a Remispora species. Remispora spitsbergenensis resembles R. quadriremis and R. stellata because all possess four or more ascospore appendages at one end. Remispora spitsbergenensis possesses consistently four polar appendages at each end in contrast to six in R. stellata. Also ascospore appendages of R. spitsbergenensis are ribbon-like, compared with the obclavate, curved and attenuate appendages in R. quadriremis and R. stellata. A key for the identification of the eight Remispora species is provided.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3852/08-003DOI Listing
October 2009

Degradability of the three dimethyl phthalate isomer esters (DMPEs) by a Fusarium species isolated from mangrove sediment.

Mar Pollut Bull 2009 May 7;58(5):765-8. Epub 2009 Apr 7.

Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon Tong, Hong Kong SAR, PR China.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.marpolbul.2009.03.005DOI Listing
May 2009

Havispora longyearbyenensis gen. et sp. nov.: an arctic marine fungus from Svalbard, Norway.

Mycologia 2008 Mar-Apr;100(2):291-5

Department of Biology & Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon Tong, Hong Kong SAR.

Information on the diversity and ecology of arctic marine fungi is lacking. During a short visit to Longyearbyen (78 degrees 13'N 15 degrees 33'E), Svalbard, Norway, a new marine fungus growing on driftwood collected at the shore was encountered. This taxon belongs to the Halosphaeriales (Ascomycota), a fungal order of mostly marine species. Havispora longyearbyenensis gen. et sp. nov. is morphologically similar to Nautosphaeria and Nereiospora, all with tufts of appendages at polar and equatorial positions of the ascospore but differing in color and septation of the ascospore and morphology and ontogeny of the ascospore appendage.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3852/mycologia.100.2.291DOI Listing
July 2008

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

Appl Microbiol Biotechnol 2007 Apr 11;74(6):1221-31. Epub 2007 Jan 11.

Coastal Marine Laboratory, Department of Biology, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong SAR, People's Republic of China.

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.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00253-006-0780-0DOI Listing
April 2007