Mangrove Fungus Research Articles

Morphological, molecular and 3D synchrotron X-ray tomographic characterizations of Helicascus satunensis sp. nov., a novel mangrove fungus.

A new species of Helicascus satunensis sp. nov. was collected on mature dead fruits of the Nypa palm in Satun Province, southern Thailand. Its morphological characteristics are similar to those of the genus Helicascus. Recently, a genus Helicascus with three species from marine habitats worldwide was studied. The morphology of this fungus was investigated and combined with multigene sequence analyzes of small subunit (SSU), large subunit (LSU), internal transcribed spacer (ITS) ribosomal DNA, translation elongation factor 1-alpha (TEF-1α) and RNA polymerase II (RPB2) genes. Morphologically, H. satunensis sp. nov. is characterized by semi-immersed, lenticular ascomata, multilocules, a bitunicate ascus and smooth, obovoid, dark brown ascospores that are one-septate and unequally two-celled. In addition, 3D visualization using synchrotron X-ray tomography was performed to investigate the interaction between fruiting body and substrata. Molecular phylogeny with multigene revealed that H. satunensis sp. nov. belongs to the family Morosphaeriaceae, order Pleosporales, class Dothideomycetes. Furthermore, H. satunensis sp. nov. forms a well-supported clade with Helicascus species described from marine habitats. Based on the unique morphological and molecular evidence, we propose this fungus, H. satunensis sp. nov., as a new species for Helicascus.

Talaketides A−G, linear polyketides with prostate cancer cytotoxic activity from the mangrove sediment-derived fungus Talaromyces sp. SCSIO 41027

Seven novel linear polyketides, talaketides A−G (1−7), were isolated from the rice media cultures of the mangrove sediment-derived fungus Talaromyces sp. SCSIO 41027. Among these, talaketides A−E (1−5) represented unprecedented unsaturated linear polyketides with an epoxy ring structure. The structures, including absolute configurations of these compounds, were elucidated through detailed analyses of nuclear magnetic resonance (NMR) and high-resolution mass spectrometry (HR-MS) data, as well as electronic custom distributors (ECD) calculations. In the cytotoxicity screening against prostate cancer cell lines, talaketide E (5) demonstrated a dose-dependent inhibitory effect on prostate cancer PC-3 cell lines, with an IC50 value of 14.44 μmol·L−1 . Moreover, compound 5 significantly inhibited the cloning formation of PC-3 cell lines and arrested the cell cycle in S-phase, ultimately inducing apoptosis. These findings indicate that compound 5 may serve as a promising lead compound for the development of a potential treatment for prostate cancer.

A Marine-Derived Small Molecule Inhibits Prostate Cancer Growth by Promoting Endoplasmic Reticulum Stress Induced Apoptosis and Autophagy.

MHO7 (6-epi-ophiobolin G), a novel component extracted from a mangrove fungus, exhibits significant anticancer effects against breast cancer. However, the precise mechanism underlying the anticancer effects of MHO7 in prostate cancer (PCa) is yet to be fully elucidated. Therefore, this study was undertaken to assess the effect of MHO7 on PCa cells and elucidate its underlying mechanism. A series of in vitro experiments were conducted, including Cell Counting Kit-8, and plate clone formation assays, flow cytometry analysis, electron microscopy, immunofluorescence staining, western blotting, and molecular dynamics simulation. Additionally, in vivo tumor xenograft models were employed. Our findings revealed that MHO7 could induce cellular autophagy at low concentration (2 μM) and apoptosis at relatively high concentration (4 and 8 μM), leading to significant PCa cell growth inhibition. Furthermore, MHO7 triggered endoplasmic reticulum (ER) stress, which subsequently stimulated autophagy and apoptosis via IRE1α/XBP-1s signaling pathway activation. Notably, IRE1α knockdown markedly reduced MHO7-induced autophagy and apoptosis. Moreover, MHO7 targeted the IRE1α protein, thereby enhancing its stability. MHO7 also exhibited substantial anticancer activity in tumor xenograft models. Our study revealed that MHO7 holds considerable potential as an anticancer agent against PCa, attributable to its activation of ER stress-induced autophagy and apoptosis at different concentrations, facilitated by the upregulation of IRE1α expression.

Mangrove fungi in action: Novel bioremediation strategy for high-chloride wastewater

Bioremediation of extremely high-chloride wastewater poses significant challenges due to the adverse effects of elevated salt concentrations on most microorganisms, where chloride levels can be as high as 7% (w/v). Mangrove wetlands derived fungus, Aspergillus aculeatus, emerged as a promising candidate, capable of removing approximately 40% of chloride ions in environments with concentration of 15% (w/v), representative of industrial wastewater conditions. Transcriptomics and biochemical assays conducted under increasing salt conditions revealed that elevated chloride concentrations induce the expression and activity of S-adenosyl methionine-dependent methyltransferase, which facilitates the conversion of chloride into chloromethane. This is the first report characterizing the biological mechanism behind high salt tolerance and chloride removal capacity of Aspergillus aculeatus. This salt remediation mechanism may work as a starter for developing future bioremediation strategies to treat high-chloride wastewater using fungi, offering an eco-friendly alternative to traditional physical or chemical methods.

Investigating the function of mangrove mycorrhizal fungi with special emphasis on arbuscular mycorrhizae (AMF) symbiosis in promoting ecosystem health and sustainability

Investigating the function of mangrove mycorrhizal fungi with special emphasis on arbuscular mycorrhizae (AMF) symbiosis in promoting ecosystem health and sustainability

Tannery effluent treatments with mangrove fungi, grass root biomass, and biochar.

Tannery effluents contain high amounts of polluting chemicals, such as salts and heavy metals released often to surface waters. New economic and eco-friendly purification methods are needed. Two adsorbing materials and five salt-tolerant fungal isolates from mangrove habitat were studied. Purification experiments were carried out using the pollutant adsorbents biochar and the biomass of vetiver grass (Chrysopogonzizanioides) roots and the fungi Cladosporium cladosporioides, Phomopsis glabrae, Aspergillus niger, Emericellopsis sp., and Scopulariopsissp., which were isolated from mangrove sediment. They efficacy to reduce pollutants was studied in different combinations. Salinity, turbidity, total dissolved solids, total suspended solids, phenols, nitrogen, ammonia. Biological and chemical oxygen demand (BOD, COD) and several heavy metals were measured. The adsorbents were efficient reducing the pollutants to 15-50% of the original. The efficiency of the combination of biochar and roots was generally at the same level as the adsorbents alone. Some pollutants such as turbidity, COD and ammonium were reduced slightly more by the combination than the adsorbents alone. From all 14 treatments, Emericellopsis sp.with biochar and roots appeared to be the most efficient reducing pollutants to < 10-30%. BOD and COD were reduced to ca 5% of the original. The treatment was efficient in reducing also heavy metals (As, Cd, Cr, Mn Pb, Zn). The fungal species originating from the environment instead of the strains present in the tannery effluent reduced pollutants remarkably and the adsorbents improved the reduction efficiency. However, the method needs development for effluents with high pollutant concentrations to fulfil the environmental regulations.

Four New Isocoumarins from the Mangrove Fungus Alternaria Malorum with Antimicrobial Activities.

Four new isocoumarins, alternariethers A-C (1-3) and alternariester (4) were separated from the fermentation of the fungus Alternaria malorum FL39, purified from Myoporum bontioides. Their structures were ascertained using NMR and HR-ESI-MS spectroscopy. For compound 4, the absolute configuration was solved with the help of ECD calculation and the DP4+ method. Compared with the positive control triadimefon, compound 1 showed more potent antifungal effects on Colletotrichum musae. The antifungal effects of compounds 1, 2, and 3 on Fusarium oxysporum and Fusarium graminearum, of compound 4 on F. oxysporum, were equal to those of triadimefon. Except for compound 4 which was inactive against Escherichia coli with O78 serotype, all compounds showed moderate or weak antibacterial activity against Staphylococcus aureus ATCC 6538 and E. coli with O6 or O78 serotype.

Two New Sesquiterpenoids and a New Shikimic Acid Metabolite from Mangrove Sediment-Derived Fungus Roussoella sp. SCSIO 41427.

Two new sesquiterpenoid derivatives, elgonenes M (1) and N (2), and a new shikimic acid metabolite, methyl 5-O-acetyl-5-epi-shikimate (3), were isolated from the mangrove sediment-derived fungus Roussoella sp. SCSIO 41427 together with fourteen known compounds (4-17). The planar structures were elucidated through nuclear magnetic resonance (NMR) and mass spectroscopic (MS) analyses. The relative configurations of 1-3 were ascertained by NOESY experiments, while their absolute configurations were determined by electronic circular dichroism (ECD) calculation. Elgonene M (1) exhibited inhibition of interleukin-1β (IL-1β) mRNA, a pro-inflammatory cytokine, at a concentration of 5 μM, with an inhibitory ratio of 31.14%. On the other hand, elgonene N (2) demonstrated inhibition at a concentration of 20 μM, with inhibitory ratios of 27.57%.

Isolation and identification of mangrove root fungi and their antimicrobial properties

Isolation and identification of mangrove root fungi and their antimicrobial properties

Discovery of a novel anti-osteoporotic agent from marine fungus-derived structurally diverse sirenins

Thirteen new sirenin derivatives named eupenicisirenins C–O (1–13), along with a biosynthetically related known one (14), were isolated from the mangrove sediment-derived fungus Penicillium sp. SCSIO 41410. The structures, which possessed a rare cyclopropane moiety, were confirmed by extensive analyses of the spectroscopic data, quantum chemical calculations, and X-ray diffraction. Among them, eupenicisirenin C (1) exhibited the strongest NF-κB inhibitory activities, as well as suppressing effects on cGAS-STING pathway. Moreover, 1 showed the significant inhibitory effect on RANKL-induced osteoclast differentiation in bone marrow macrophages cells, and also displayed the therapeutic potential on prednisolone-induced zebrafish osteoporosis. Transcriptome analysis and the following verification tests suggested that its anti-osteoporotic mechanism is related to the extracellular matrix receptor interaction-related pathways. This study provided a promising marine-derived anti-osteoporotic agent for the treatment of skeletal disease.

Distribution patterns of endophytic fungi in different intertidal plant communities within a tropical mangrove forest in South China

Fungi play a crucial role in the growth of mangrove plants in various intertidal zones. However, our knowledge of the endophytic fungi in mangroves is limited. In this study, we analyzed the distribution patterns of endophytic fungi in true mangroves (TM), mangrove associates (MA), and other plants (OP) in a tropical mangrove forest. The results showed that Lulwoana, Fusarium, and Aspergillus were the predominant endophytic fungal taxa in TM, MA, and OP, respectively. Non-metric multidimensional scaling demonstrated significant differences in the endophytic fungal community structure among different intertidal plant communities, highlighting the plant-mediated selection of endophytic fungi. In addition, tides and plant species may affect endophytic fungal communities by altering soil properties. The colonization of arbuscular mycorrhizal fungi (AMF) and dark septate endophytes (DSE) was higher in MA, possibly because of variations in soil pH and available phosphorus content. Phylogenetic analyses indicated that family Diversisporaceae and Par1 (Paraglomeraceae) were exclusively found in the mangrove associates, whereas Glome4 (Glomeraceae) and Par2 (Paraglomeraceae) were observed only in the TM. These results support the high variation in AMF communities among the different intertidal plant communities. This study emphasizes the critical role of tides and plant species in shaping the composition of endophytic fungal communities, which has significant implications for the conservation and restoration of mangrove ecosystems.

Lecanicilliums A-F, Thiodiketopiperazine-Class Alkaloids from a Mangrove Sediment-Derived Fungus Lecanicillium kalimantanense.

Six new thiodiketopiperazine-class alkaloids lecanicilliums A-F were isolated from the mangrove sediment-derived fungus Lecanicillium kalimantanense SCSIO41702, together with thirteen known analogues. Their structures were determined by spectroscopic analysis. The absolute configurations were determined by quantum chemical calculations. Electronic circular dichroism (ECD) spectra and the structure of Lecanicillium C were further confirmed by a single-crystal X-ray diffraction analysis. Lecanicillium A contained an unprecedented 6/5/6/5/7/6 cyclic system with a spirocyclic center at C-2'. Biologically, lecanicillium E, emethacin B, and versicolor A displayed significant cytotoxicity against human lung adenocarcinoma cell line H1975, with IC50 values of 7.2~16.9 μM, and lecanicillium E also showed antibacterial activity against four pathogens with MIC values of 10~40 μg/mL. Their structure-activity relationship is also discussed.

Dechlorination of wastewater from shell-based glucosamine processing by mangrove wetland-derived fungi.

Wastewater from processing crustacean shell features ultrahigh chloride content. Bioremediation of the wastewater is challenging due to the high chloride ion content, making it inhospitable for most microorganisms to survive and growth. In this study, mangrove wetland-derived fungi were first tested for their salt tolerance, and the highly tolerant isolates were cultured in shrimp processing wastewater and the chloride concentration was monitored. Notably, the filamentous fungal species Aspergillus piperis could remove over 70% of the chloride in the wastewater within 3 days, with the fastest biomass increase (2.01 times heavier) and chloride removal occurring between day one and two. The chloride ions were sequestered into the fungal cells. The genome of this fungal species contained Cl- conversion enzymes, which may have contributed to the ion removal. The fungal strain was found to be of low virulence in larval models and could serve as a starting point for further considerations in bioremediation of shell processing wastewater, promoting the development of green technology in the shell processing industry.

Endophyte fungi from Agarwood and Mangrove and their applications

Mangroves are woody trees or shrubs salt marsh halophytes that encompass over 75% of the tropical coastline on the planet. Mangroves are characterized by their sophisticated morphological and physiological adaptations as well as their rich synthesis of biologically active secondary metabolites. They also contribute in decreasing CO2 levels in the atmosphere through photosynthesis. On the other hand, agarwood, is an aromatic perfumed precious heartwood of diseased timber of Aquilaria and Gyrinops trees that is used centuries ago till now as incense in religious ceremonies, raw material in the perfume industry and as a medicine. Agarwood formation is usually induced by wounding trunks and branches of Aquilaria trees. Production of natural agarwood resin is inefficient and don’t meet global demand, so different methods have been applied to stimulate biological agarwood induction, and using endophytic fungi is one of the methods. Hence, this review highlights the importance of endophytic fungi in mangroves and agarwood, their existence and some of their important biological activities.

Diversity of marine fungi in Pondicherry mangroves, east coast of India and systematic placement of Rhizophila marina

Abstract Although many novel marine fungi have been described from Indian mangroves, a significant number of mangroves in India have not been thoroughly investigated for marine fungi. This study highlights the diversity of marine fungi inhabiting dead and decaying wood of Avicennia marina and Rhizophora mucronata, collected from Thengaithittu and Veerampattinam mangroves of Pondicherry, Puducherry State, India. Through microscopic examination, a total of 52 species (in 48 genera) of marine fungi were identified, with 50 species (in 46 genera) belonging to the Ascomycota and 2 species (in 2 genera) belonging to the Basidiomycota. Previous studies recorded 69 marine fungi from Ariyankuppam and Mahé mangroves of Puducherry, and this study contributes 22 new records of marine fungi to this region. In this study, the phylogenetic placement of Rhizophila marina was determined, and this fungus was found to belong to the family Diatrypaceae.

Long-read assembled metagenomic approaches improve our understanding on metabolic potentials of microbial community in mangrove sediments

BackgroundMangrove wetlands are coastal ecosystems with important ecological features and provide habitats for diverse microorganisms with key roles in nutrient and biogeochemical cycling. However, the overall metabolic potentials and ecological roles of microbial community in mangrove sediment are remained unanswered. In current study, the microbial and metabolic profiles of prokaryotic and fungal communities in mangrove sediments were investigated using metagenomic analysis based on PacBio single-molecule real time (SMRT) and Illumina sequencing techniques.ResultsComparing to Illumina short reads, the incorporation of PacBio long reads significantly contributed to more contiguous assemblies, yielded more than doubled high-quality metagenome-assembled genomes (MAGs), and improved the novelty of the MAGs. Further metabolic reconstruction for recovered MAGs showed that prokaryotes potentially played an essential role in carbon cycling in mangrove sediment, displaying versatile metabolic potential for degrading organic carbons, fermentation, autotrophy, and carbon fixation. Mangrove fungi also functioned as a player in carbon cycling, potentially involved in the degradation of various carbohydrate and peptide substrates. Notably, a new candidate bacterial phylum named as Candidatus Cosmopoliota with a ubiquitous distribution is proposed. Genomic analysis revealed that this new phylum is capable of utilizing various types of organic substrates, anaerobic fermentation, and carbon fixation with the Wood-Ljungdahl (WL) pathway and the reverse tricarboxylic acid (rTCA) cycle.ConclusionsThe study not only highlights the advantages of HiSeq-PacBio Hybrid assembly for a more complete profiling of environmental microbiomes but also expands our understanding of the microbial diversity and potential roles of distinct microbial groups in biogeochemical cycling in mangrove sediment.-S53N_3zEPEL_LmTMdKdCcVideo

Diversity and bioactivity of sediment-associated fungi from a mangrove forest in Mexico with different conservation conditions

The biological importance of rhizosphere sediment-associated fungi in mangroves is poorly understood, especially when they are affected by high salinity and anaerobiosis in disturbed areas. This study evaluated the fungal diversity in the rhizosphere sediments of three mangrove species associated with three conservation conditions of mangrove forests in preserved, semi-preserved, and deteriorated areas. In addition, fungal bioactivity was correlated to the fungal diversity found in mangrove species from each area. We isolated 50 fungal strains belonging to three phyla, seven classes, and 10 orders. The fungal diversity was higher in the preserved area (H' = 2.22) than in the semi-preserved (H' = 1.73) and deteriorated areas (H' = 1.68); the redundancy analysis showed a tendency of fungal accumulation towards the rhizosphere of Rhizophora mangle and Avicennia germinans in the preserved and semi-preserved areas. In addition, the redundancy analysis showed that 10 bioactive fungi genera tended to accumulate on the rhizosphere of R. mangle and A. germinans in the preserved and semi-preserved areas. The preserved area is related to the semi-preserved area, with a 28% Jaccard similarity coefficient. The diversity and bioactivity of the isolated fungi encourage the need to conserve and restore mangrove ecosystems considering their current and potential services, such as bioprospecting new pharmacological compounds.

Bioactive Polyketides and Benzene Derivatives from Two Mangrove Sediment-Derived Fungi in the Beibu Gulf.

To discover bioactive natural products from mangrove sediment-derived microbes, a chemical investigation of the two Beibu Gulf-derived fungi strains, Talaromyces sp. SCSIO 41050 and Penicillium sp. SCSIO 41411, led to the isolation of 23 natural products. Five of them were identified as new ones, including two polyketide derivatives with unusual acid anhydride moieties named cordyanhydride A ethyl ester (1) and maleicanhydridane (4), and three hydroxyphenylacetic acid derivatives named stachylines H-J (10-12). Their structures were determined by detailed nuclear magnetic resonance (NMR) and mass spectroscopic (MS) analyses, while the absolute configurations were established by theoretical electronic circular dichroism (ECD) calculation. A variety of bioactive screens revealed three polyketide derivatives (1-3) with obvious antifungal activities, and 4 displayed moderate cytotoxicity against cell lines A549 and WPMY-1. Compounds 1 and 6 at 10 μM exhibited obvious inhibition against phosphodiesterase 4 (PDE4) with inhibitory ratios of 49.7% and 39.6%, respectively, while 5, 10, and 11 showed the potential of inhibiting acetylcholinesterase (AChE) by an enzyme activity test, as well as in silico docking analysis.

Community assembly and network structure of epiphytic and endophytic phyllosphere fungi in a subtropical mangrove ecosystem.

Microorganisms can influence plant growth and health, ecosystem functioning, and stability. Community and network structures of mangrove phyllosphere fungi have rarely been studied although mangroves have very important ecological and economical values. Here, we used high throughput sequencing of the internal transcribed spacer 2 (ITS2) to assess epiphytic and endophytic phyllosphere fungal communities of six true mangrove species and five mangrove associates. Totally, we obtained 1,391 fungal operational taxonomic units (OTUs), including 596 specific epiphytic fungi, 600 specific endophytic fungi, and 195 shared fungi. The richness and community composition differed significantly for epiphytes and endophytes. Phylogeny of the host plant had a significant constraint on epiphytes but not endophytes. Network analyses showed that plant-epiphyte and plant-endophyte networks exhibited strong specialization and modularity but low connectance and anti-nestedness. Compared to plant-endophyte network, plant-epiphyte network showed stronger specialization, modularity, and robustness but lower connectance and anti-nestedness. These differences in community and network structures of epiphytes and endophytes may be caused by spatial niche partitioning, indicating their underlying ecological and environmental drivers are inconsistent. We highlight the important role of plant phylogeny in the assembly of epiphytic but not endophytic fungal communities in mangrove ecosystems.

Eremophilanolide sulfoxides and eremophilanolides from the mangrove fungus TBRC-BCC 64093

Two unusual eremophilanolide sulfoxide diastereomers (1 and 2), seven eremophilanolides (3–7, 11, and 12) together with nine known eremophilanolides (8–10 and 13–18), anserinone A (19), and (−)-mellein-5-carboxylic acid (20) were isolated from the mangrove fungus TBRC-BCC 64093, a member of family Xylariaceae. The structures of these compounds were elucidated by extensive spectroscopic analysis of their NMR and MS data. The absolute configurations of the eremophilane sulfoxide diastereomers were determined by comparison of experimental and calculated electronic circular dichroism (ECD) data by TDDFT. Among the tested metabolites, eremophilane sulfoxide 1 showed weak cytotoxic activity against Vero cell lines with an IC50 value of 17.7 μg/mL.