Chemical and biological potential of fungi from deep-sea hydrothermal vents and an oxygen minimum zone
-
Patricia Velez
Dr. Patricia Velez earned her B.S. (2008), M.S. (2010), and Ph.D. (2014) degrees in Biological Sciences from the UNAM for her work on arenicolous marine fungi. Next, she performed two postdoctoral stays at the UNAM and the CICESE studying molecular ecology of freshwater and deep-sea fungi respectively. She is now a faculty member and full-time researcher at the Institute of Biology, UNAM where her work focuses on the exploration of fungal diversity, ecology, and potential utilization, particularly in marine ecosystems.
,
Jaime Gasca-Pineda
Dr. Jaime Gasca-Pineda is a postdoctoral researcher at the Ecology Institute in the National Autonomous University of Mexico (UNAM). He specializes in population genetics and bioinformatics. Currently, his work focuses on the evaluation of the genomic diversity of wild relatives of Mexican crops and the genomics of marine fungi.
Abril Hernandez-Monroy is a PhD student at the Biology Institute of the National Autonomous University of Mexico. Her research focuses on fungal-bacteria interactions from organisms isolated from deep-sea hydrothermal vents, a topic she has explored from various perspectives, including culturing and transcriptomics. Her doctoral work focuses on elucidating the molecular and phenotypic mechanisms underlying microbial adaptation to long-term interspecies interactions.
Dr. Mario Figueroa received his B.S. (2004), M.S. (2006), and Ph.D. (2009) degrees in Chemistry from UNAM under the mentorship of Professor Rachel Mata. After two postdoctoral stays at Lehman College, NY, and UNCG, NC, he returned to Facultad de Química, UNAM, where he became a full professor. His research focuses on the chemistry and biology of microbes from unexplored areas of Mexico. He has published over 65 peer-reviewed papers and 4 book chapters and is a co-inventor on three patents.
Abstract
Recent research has evidenced that deep-sea extreme ecosystems represent untapped reservoirs of distinctive microbial species with potential biotechnological applications. Herein, we described the fungal community associated with sediments collected in deep-sea hydrothermal vent systems and an oxygen minimum zone in the Gulf of California and explored their biotechnological potential through an integrated approach based on the culture of the strains in different conditions and a metabolomic analysis. A total of 32 Ascomycota isolates were obtained and taxonomically identified into 14 operational taxonomic units (OTUs) based on their morphology and analysis of the internal transcribed spacers (ITS) of rDNA and the beta-tubulin gene (benA). Selected isolates were tested for their growth under different temperatures and for their antibacterial activity against a set of human microbial pathogens. Based on their observed antimicrobial activities, extracts of Aspergillus cejpii (isolate I), Leiothecium ellipsoideum (isolate O), and Aspergillus sp. 2 (isolate W) were selected for a bioactivity-directed chemical study, which produced several secondary metabolites with reported antibacterial, antiparasitic and cytotoxic activities. These results evidence that the explored deep-sea extreme systems harbor promising fungal genetic resources and pave the way towards comprehending deep-sea fungal diversity and its potential utilization.
1 Introduction
The deep-sea covers over 65 % of the Earth’s surface, representing the largest biome (Herring 2001). Nonetheless, given its remoteness and exploration challenges, it remains mostly unknown (Tyler 2003). This fascinating submarine biome includes numerous ecosystems, from desert-like anoxic waters to rich oases at hydrothermal vents, that harbor surprisingly high microbial diversity levels (Paulus 2021), where photosynthesis does not support primary productivity. In this context, the microscopic component of communities sustains life by driving crucial ecosystem functions (e.g., in the carbon, manganese, nitrogen, and sulfur cycles) (Blöthe et al. 2015; Hutchins and Capone 2022; Zheng et al. 2021).
Hydrothermal vents and oxygen minimum zones (OMZ) represent unique and extreme deep-sea ecosystems where an extraordinary diversity of previously undetected eukaryotic lineages has been recently uncovered (Edgcomb et al. 2007). The temperature of active deep-sea vent fluids ranges between 25 °C and 350 °C, and around 4 °C in the sediments (Jannasch and Mottl 1985). These systems have been distinguished for hosting an exceptional microbial diversity (Kelley et al. 2001) that includes chemolithoautotrophic and heterotrophic microorganisms, resulting in one of the most productive ecosystems on earth (Levin et al. 2016). On the other hand, OMZ are characterized by extremely low oxygen concentrations (<20–45 μmol kg−1; Gilly et al. 2013) and are known to support thriving microbial communities (Wright et al. 2012). This low oxygen condition favors anaerobic microbial processes that impact marine productivity and climate balance (Karstensen et al. 2008). However, most of the investigations related to the microbiology of these systems have focused on the prokaryotic communities (reviewed in Dick 2019), neglecting microeukaryotes, particularly fungi.
Relatively little is known about fungal diversity and its adaptations to deep-sea environments alhough, over the past decade, it has become increasingly clear that these microeukaryotes thrive in sediments of vent fields (Dekov et al. 2013) and OMZ (Manohar et al. 2015), playing key functional roles (Peng and Valentine 2021; Salcedo et al. 2023). Pioneer culture-based investigations have revealed a high abundance of Ascomycota and Basidiomycota representatives, in addition to several undescribed phylotypes (Burgaud et al. 2010, 2011, 2016; Le Calvez et al. 2009; Xu et al. 2017, 2018). In terms of fungal adaptation, growth rates under 25 °C and 45 °C were assessed in Aspergillus terreus isolated from hydrothermal vent sediments, evidencing that this isolate exhibits physiological capacities to develop under both conditions (Guo et al. 2025). Still, few studies have investigated the cultivable portion of fungal communities and their growth response to different temperatures, hampering the evaluation of their ecological roles and potential utilization in biotechnology.
Extreme, unexplored environments are untapped reservoirs of unique microbial communities with the potential to enhance our current arsenal of compounds with biomedical and/or industrial applications (Keeler et al. 2021). In this sense, over the past 20 years, numerous reports have evidenced that hydrothermal vents provide a prolific source of microbial-derived secondary metabolites (Demain 2014). Examples include compounds with antibiotic effect against human bacterial pathogens (Keeler et al. 2021), and numerous new molecules (Jiang et al. 2013; Lai et al. 2022; Pan et al. 2016, 2017, 2018; Tao et al. 2018; Ye et al. 2014). Natural product discovery has been less investigated in microbes from OMZ, with a few reports highlighting their prominent antimicrobial capacities (Barone et al. 2019; Geller-McGrath et al. 2023; Inostroza et al. 2018).
Given that the diversity and biotechnological potential of fungi from deep-sea extreme ecosystems remain poorly understood, we implemented a culture-dependent approach to obtain axenic isolates from hydrothermally influenced sediment samples and an OMZ in the Gulf of California, Mexico. Fungi were identified and tested for their growth under different temperatures (20 °C, 35 °C, and 50 °C) and for their antibacterial activity against human pathogens (Bacillus spizizenii ATCC 6633, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 10536, Pseudomonas aeruginosa ATCC 27853, and Salmonella typhi ATCC 33459, and the yeast Candida albicans ATCC 10231). Lastly, selected fungal isolates were used for a bioactivity-directed chemical study.
2 Materials and methods
2.1 Isolation and identification of fungi
Sediment cores were collected by Dr. Diana L. Salcedo in collaboration with the Monterey Bay Aquarium Research Institute. The sampling was conducted onboard the R/V Western Flyer using the remote-operated vehicle Doc Ricketts in 2015 in four deep-sea locations within the Gulf of California, including the hydrothermal vents: Pescadero Basin (PV), Pescadero Transform Fault (FI), and Alarcón Rise (AV); and an OMZ in the Alfonso Basin (ZM) (Figure 1). The temperature of vent fluids in these systems ranged from 359 °C (AV) to 5 °C (FI). A thorough description of the abiotic setting of these systems is reported by Clague et al. (2018).
Sampling sites: the hydrothermal vent systems of the Pescadero Basin (PV_1 and PV_3), Pescadero Transform Fault (FI_4 and FI_5), and Alarcón Rise (AV_1), and the oxygen minimum zone at the Alfonso Basin (ZM_1 and ZM_2), Gulf of California, Mexico.
In the laboratory, under sterile conditions, a sub-sample from the inner portion of each core (15 × 3 cm) was collected for fungal isolation using the direct plating method (Warcup 1950) on potato dextrose agar (PDA; Becton Dickinson) and corn meal agar (Becton Dickinson). Culture media were supplemented with artificial sea salts (Fluval Sea) at a final concentration of 36 g l−1 and an antibiotic mixture of streptomycin sulfate and penicillin G (250 mg l−1 each). Petri dishes were incubated at room temperature (∼22 °C) in absolute dark conditions for approximately 4 weeks. The plates were examined daily for fungal growth, and developing colonies were subsequently transferred to PDA.
Fungi were identified by morphology and molecular sequence analyses. Total genomic DNA was extracted from axenic isolates using the cetyltrimethylammonium bromide protocol (Doyle and Doyle 1987) and stored at 4 °C until use. The internal transcribed spacer regions of the nuclear ribosomal DNA (ITS1-5.8S rDNA-ITS2; hereafter referred to as ITS) were amplified with primers ITS1 (5-TCCGTAGGTGAACCTGCGG-3) and ITS4 (5-TCCTCCGCTTATTGATATGC-3) using previously reported parameters (White et al. 1990). In addition, to improve taxonomic resolution, the beta-tubulin gene (benA) was amplified with primers Bt2A (5-GGTAACCAAATCGGTGCTGCTTTC-3) and Bt2b (5-ACCCTCAGTGTAGTGACCCTTGGC-3) as reported by Glass and Donaldson (1995). The PCR products were commercially sequenced in both directions (Laboratorio de Secuenciación Genómica de la Biodiversidad, Biology Institute, National Autonomous University of Mexico, Mexico City). Fungal cultures and DNA extracts were deposited at Laboratory C-202 (former C-121), Biology Institute, UNAM, headed by Dr. Patricia Velez, and are fully available for research upon request.
Quality examination and assembly of the forward and the reverse sequences were done using the Consed software version 28.0 (Ewing and Green 1998; Ewing et al. 1998; Gordon et al. 2001). Sequences were compared against the GenBank database through a BLAST search (http://www.ncbi.nlm.nih.gov/BLAST) to retrieve reference sequences. Hit sequences with a minimum of >88 % coverage were considered, favoring accessions associated with vouchers. Taxonomic assignment was defined from the best-scoring reference sequence of the blast output according to the criteria suggested by Millberg et al. (2015), with a sequence similarity cut-off value of 98–100 % for species level, 94–97 % for genus level and 80–93 % for order level identifications. For contradictory scores, the lowest common rank level was used (Persoh et al. 2010) and key morphological traits were examined. Reference ITS and beta-tubulin sequences retrieved from the GenBank database considered for the taxonomic assignment are listed in Supplementary Table 1.
Reference sequences and sequences generated in this study were aligned with the program MUSCLE (Edgar 2004). A maximum likelihood phylogenetic tree was constructed using IQ-TREE v2.3.6 (Minh et al. 2020). The program was run using 1,000 non-parametric bootstrap with five independent runs. The evolutionary model was selected using the option MFP (ModelFinder Plus, Kalyaanamoorthy et al. 2017). Additionally, a Bayesian reconstruction using BEAST v1.10.4 (Suchard et al. 2018) was calculated to confirm the taxonomic identifications. The Bayesian analysis was run for 500,000,000 MCMC chains with 10 % burn-in, using the substitution model GTR+I+G obtained with jModelTest2 version 2.1.7 (Darriba et al. 2012; Guindon and Gascuel 2003). To assess chain convergence, the log posterior probability of the sampled parameter values was plotted using Tracer v.1.7.1 (Rambaut et al. 2018), assuring effective sample sizes (ESS) of 200 or more. The tree was visualized using FigTree version 1.4.4 (Rambaut and Drummond 2018).
2.2 Growth rates under different temperatures
A representative isolate of each operational taxonomic unit (OTU) was selected to explore fungal thermotolerance (Supplementary Table S1). Petri plates with GYPS medium (glucose 1 g l−1, yeast extract 1 g l−1, peptone 1 g l−1, starch 1 g l−1, sea salts 30 g l−1, and agar 15 g l−1; Le Calvez et al. 2009) were inoculated with 10 μl of spore suspensions (OD 1.0 ± 0.2 at 600 nm) prepared with actively growing 8-day old colonies. The experiment was run in triplicate. Plates were incubated at 20 °C, and 35 °C in dark conditions. A photographic record of the plates was registered using a Nikon D3000 digital SLR camera (Nikon Inc., Tokyo, Japan) after 4, 7, 11, and 14 days of the inoculation. Area of radial mycelial growth on the plates was determined through image analysis using the software IMAGEJ 1.52a (Schneider et al. 2012). For growth evaluation at 50 °C, the experiment was performed in triplicate using GYPS liquid culture medium (without agar), and dry biomass was determined for each isolate.
2.3 Fungal cultures for solid-state fermentation and extract preparation
Agar plugs (3–5 plugs, 1 cm2 each) of each fungus were inoculated into 2 × 15 ml YESD medium (2 % soy peptone, 2 % dextrose, and 1 % yeast extract in 1 l distilled water), incubated for 5 days at room temperature (∼22 °C), and transferred to 2 × 250 ml Erlenmeyer flasks with a rice medium (15 g/30 ml H2O). After 21 days of incubation at room temperature (∼22 °C), the cultures were extracted with 100 ml of MeOH–CHCl3 (1:1), and the filtrate was evaporated to dryness under vacuum. The resulting extracts were partitioned between n-hexane and CH3CN–MeOH (1:1), and the CH3CN–MeOH (1:1) layer was collected and evaporated to dryness. For Aspergillus cejpii (isolate I), Leiothecium ellipsoideum (isolate O), and Aspergillus sp. 2 (isolate W), 10 flasks were prepared in the same manner, yielding 485.9 mg, 1.1 g, and 530.0 mg of organic extracts, respectively.
2.4 Chemical analyses and isolation and identification of secondary metabolites
Nuclear magnetic resonance (NMR) analyses were performed on a Varian VNRMS 400 spectrometer (Varian Inc.; 400 MHz for 1H and 100 MHZ for 13C). HRESIMS-MS/MS data were collected using a Q Exactive mass spectrometer (ThermoFisher Scientific) in positive and negative modes (ESI+ and ESI−). Samples were introduced to the spectrometer via an Acquity UPLC system (Waters Corp.). A CombiFlash Rf+ Lumen system was employed using RediSep Rf Si-gel Gold columns (both from Teledyne-Isco). High-performance liquid chromatography (HPLC) separations were performed using a Waters system (Waters Corp.) equipped with a quaternary pump, autoinjector, photodiode array detector (PDA), evaporative light scattering detector (ELSD), and fraction collector. HPLC control and data acquisition were performed with Empower 3 software (Waters Corp.). Gemini C18 columns (5 μm; 250 × 4.6 mm for analytical or 250 × 21.2 mm for preparative separation) were used.
Extracts of A. cejpii (isolate I), L. ellipsoideum (isolate O), and Aspergillus sp. 2 (isolate W) were fractionated by flash chromatography on a RediSep Rf Gold Si-gel column eluting with sequential mixtures of n-hexane-CHCl3-EtOAc-MeOH at 30 ml min−1, to obtain 13, 17, and 14 primary fractions, respectively. For A. cejpii (isolate I), active fraction Fr. I-9 (57.9 mg) was subjected to preparative HPLC using a gradient system from 30:70 to 100:0 of CH3CN–H2O (0.1 % formic acid) in 15 min at 21.24 ml min−1 yielding compound 1 (13.6 mg, tR = 7.2 min) and compound 2 (2.0 mg, tR = 10.4 min). Fraction Fr. I-10 (65.4 mg) was subjected to preparative HPLC using a gradient system from 30:70 to 100:0 of CH3CN–H2O (0.1 % formic acid) in 15 min at 21.24 ml min−1 yielding compound 3 (2.8 mg, tR = 8.2 min) and additional amounts of compound 2 (1.0 mg, tR = 10.4 min). For L. ellipsoideum (isolate O), fraction Fr. O-8 (100.5 mg) was subjected to preparative HPLC using a gradient system from 15:85 to 100:0 of CH3CN–H2O (0.1 % formic acid) in 10 min at 21.24 ml min−1 yielding compound 4 (2.8 mg, tR = 6.28 min) and compound 5 (3.0 mg, tR = 8.53 min). For Aspergillus sp. 2 (isolate W), fraction Fr. W-6 (7.2 mg) was subjected to analytical HPLC using a gradient system from 15:85 to 100:0 of CH3CN–H2O (0.1 % formic acid) in 15 min at 1 ml min−1, and detected a single compound (6) in the fraction (tR = 23.4 min). Finally, fraction Fr. W-8 (70.4 mg) was subjected to preparative HPLC using a gradient system from 50:50 to 100:0 of CH3CN–H2O (0.1 % formic acid) in 15 min at 21.24 ml min−1 yielding compound 7 (1.8 mg, tR = 6.71 min). All pure compounds (>95 % purity by HPLC and NMR) were characterized using a suite of NMR and MS techniques and comparing the results with those reported in the literature.
2.5 Antimicrobial assay
Crude extracts and fractions were tested for antimicrobial activity using a microplate serial dilution method against a set of bacteria (B. spizizenii ATCC 6633, S. aureus ATCC 25923, E. coli ATCC 10536, P. aeruginosa ATCC 27853, and S. typhi ATCC 33459), and the yeast C. albicans ATCC 10231, using a previously reported method (Yeverino et al. 2025). Ampicillin was used as positive control for S. aureus, E. coli, and S. typhi; gentamicin for P. aeruginosa; vancomycin for B. subtilis; and nystatin for C. albicans. Samples were assayed in triplicate at 200 and 20 μg ml−1 (in 5 % dimethyl sulfoxide, DMSO). MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) was used to determine cell viability and growth inhibition by visually assessing turbidity.
3 Results
3.1 Cultivable diversity
Thirty-two axenic fungal isolates were obtained from the seven sediment sub-cores, clustering into 14 OTUs (Figure 2). Tree topology and BLAST hits from the GenBank database were consistent and concordant with morphology (Supplementary Figures S1 and S2). All OTUs belonged to the phylum Ascomycota, subphylum Pezizomycotina, containing members of the classes Eurotiomycetes (12 OTUs), Sordariomycetes (1 OTU), and Dothideomycetes (1 OTU). At the genus level, the isolates were distributed into six genera: Aspergillus (5 OTUs), Penicillium (4 OTUs), Talaromyces (2 OTUs), Leiothecium (1 OTU), Lepidosphaeria (1 OTU) and Zopfiella (1 OTU). The most abundant OTU was Aspergillus sydowii (exclusively isolated from PV; Table 1). In addition, our results on the experiments of fungal growth under different temperatures indicated that the isolates had a wide thermotolerance, having a growth range in 20–50 °C, yet growth at 50 °C was significantly reduced (below 0.07 g of dry weight; Figure 3).
Fungi cultured from sediments collected at three deep-sea hydrothermal vent systems and an oxygen minimum zone in the Gulf of California. Images correspond to colonies grown on GYPS medium for 13 days. (A) Aspergillus sp. 1 (isolate B). (B) Zopfiella erostrata (isolate C). (C) Lepidosphaeria sp. (isolate D). (D) Penicillium miczynskii (isolate E). (E) Talaromyces sp. 1 (isolate G). (F) Talaromyces sp. 2 (isolate H). (G) Aspergillus sydowii (isolate K). (H) Penicillium sp. 1 (isolate M). (I) Leiothecium ellipsoideum (isolate O). (J) Penicillium brefeldianum (isolate P). (K) Aspergillus cejpii (isolate R). (L) Penicillium sp. 2 (isolate U). (M) Aspergillus sp. 2 (isolate W). (N) Aspergillus terreus (isolate 43). Isolate nomenclature corresponds to Table 1.
Fungal isolates obtained from deep-sea hydrothermal vent systems and an oxygen minimum zone in the Gulf of California and their GenBank accession numbers of the internal transcribed spacers of rDNA (ITS) and the beta-tubulin gene (benA). Sampling sites are marked in Figure 1. NA, not available.
| Isolate | GenBank accession number | Species identity | System | Sampling site | Depth (m) | |
|---|---|---|---|---|---|---|
| ITS | benA | |||||
| A | PP955440 | PQ304794 | Aspergillus sp. 1 | Alarcon Rise | AV_1 | 2,176.2 |
| B | PP955440 | PQ304793 | Aspergillus sp. 1 | Alfonso Basin | ZM_1 | 409 |
| C | PP955441 | PQ304795 | Zopfiella erostrata | Alfonso Basin | ZM_1 | 409 |
| D | PP955439 | PQ304790 | Lepidosphaeria sp. | Pescadero Basin | PV_1 | 3,680.4 |
| E | PP955443 | PQ304782 | Penicillium miczynskii | Alfonso Basin | ZM_2 | 409 |
| F | PP955443 | PQ304782 | P. miczynskii | Pescadero Basin | PV_1 | 3,680.4 |
| G | PP955442 | PQ304788 | Talaromyces sp. 1 | Alarcon Rise | AV_1 | 2,176.2 |
| H | PP955438 | PQ304787 | Talaromyces sp. 2 | Alarcon Rise | AV_1 | 2,176.2 |
| I | PP955449 | PQ304784 | Aspergillus cejpii | Pescadero Transform Fault | FI_4 | 2,382.7 |
| J | PP955444 | PQ304789 | Aspergillus sydowii | Pescadero Basin | PV_3 | 3,689.7 |
| K | PP955444 | PQ304789 | A. sydowii | Pescadero Basin | PV_3 | 3,689.7 |
| K3 | PP955444 | PQ304789 | A. sydowii | Pescadero Basin | PV_3 | 3,689.7 |
| K3R | PP955444 | PQ304789 | A. sydowii | Pescadero Basin | PV_3 | 3,689.7 |
| L | PP955444 | PQ304789 | A. sydowii | Pescadero Basin | PV_3 | 3,689.7 |
| L2 | PP955444 | PQ304789 | A. sydowii | Pescadero Basin | PV_3 | 3,689.7 |
| M | PP955446 | PQ304792 | Penicillium sp. 1 | Pescadero Transform Fault | FI_4 | 2,382.7 |
| N | PP955442 | PQ304788 | Talaromyces sp. 1 | Alarcon Rise | AV_1 | 2,176.2 |
| O | NA | PQ304791 | Leiothecium ellipsoideum | Pescadero Transform Fault | FI_5 | 2,397.9 |
| P | PP955447 | PQ304781 | Penicillium brefeldianum | Alarcon Rise | AV_1 | 2,176.2 |
| Q | PP955442 | PQ304788 | Talaromyces sp. 1 | Alarcon Rise | AV_1 | 2,176.2 |
| R | PP955450 | PQ304783 | A. cejpii | Alarcon Rise | AV_1 | 2,176.2 |
| S | PP955444 | PQ304789 | A. sydowii | Pescadero Basin | PV_1 | 3,680.4 |
| T | PP955449 | PQ304784 | A. cejpii | Alarcon Rise | AV_1 | 2,176.2 |
| U | PP955437 | NA | Penicillium sp. 2 | Pescadero Transform Fault | FI_5 | 2,397.9 |
| W | PP955448 | PQ304785 | Aspergillus sp. 2 | Pescadero Transform Fault | FI_5 | 2,397.9 |
| W1 | PP955448 | PQ304785 | Aspergillus sp. 2 | Pescadero Transform Fault | FI_4 | 2,397.9 |
| W2 | PP955448 | PQ304785 | Aspergillus sp. 2 | Pescadero Transform Fault | FI_4 | 2,397.9 |
| W3 | PP955448 | PQ304785 | Aspergillus sp. 2 | Pescadero Transform Fault | FI_4 | 2,397.9 |
| X_fwd | PP955445 | PQ304787 | Talaromyces sp. 2 | Alarcon Rise | AV_1 | 2,176.2 |
| 51 | PP955441 | PQ304795 | Z. erostrata | Alfonso Basin | ZM_1 | 409 |
| 43 | PP955436 | PQ304786 | Aspergillus terreus | Pescadero Basin | PV_1 | 3,680.4 |
| 48 | PP955443 | PQ304782 | P. miczynskii | Pescadero Transform Fault | FI_4 | 2,382.7 |
Fungal growth at 20 °C, 35 °C, and 50 °C (shown in the x-axis), y-axis denotes cm2 of radial growth on Petri dishes (20 °C and 35 °C) and mg of dry biomass (50 °C). (A) Aspergillus sp. 1 (isolate B). (B) Lepidosphaeria sp. (isolate D). (C) Penicillium miczynskii (isolate F). (D) Talaromyces sp. 2 (isolate H). (E) Aspergillus sydowii (isolate K). (F) Penicillium sp. 1 (isolate M). (G) Leiothecium ellipsoideum (isolate O). (H) Penicillium brefeldianum (isolate P). (I) Talaromyces sp. 1 (isolate Q). (J) Aspergillus cejpii (isolate R). (K) Aspergillus sydowii (isolate S). (L) Aspergillus sp. 2 (isolate W). (M) Aspergillus terreus (isolate 43). Isolate nomenclature corresponds to Table 1.
Overall, the highest number of isolates was recovered from the vent systems: PV (10 isolates) followed by AV and FI. The lowest abundance was observed in the OMZ (ZM). The same pattern was observed in terms of species richness. Zopfiella erostrata was solely recovered from the OMZ; whereas 10 OTUs were restricted to vent systems (AV and PV). Paecilomyces niveus represented the only OTU recovered from both vent systems and the OMZ.
3.2 Bioactivity-directed chemical study
In order to explore the chemical diversity and antimicrobial potential of the fungal species isolated from the marine hydrothermal vents in the Gulf of California, organic extracts of 17 isolates were tested for bioactivity. Based on the antimicrobial activity results (Table 2), extracts of A. cejpii (isolate I) with inhibitory activities to four tested bacteria, L. ellipsoideum (isolate O) with an inhibitory activity to C. albicans, and Aspergillus sp. 2 (isolate W) with a strong inhibitory activity to S. aureus were selected for a downstream chemical study (Supplementary Figures S3–S24). Briefly, the extracts were fractionated by flash chromatography, and some of the most active fractions were separated by reverse-phase HPLC preparative, yielding dimethylgliotoxin (1), fiscalin C (2), and epi-fiscalin C (3) from A. cejpii, 3-hydroxybenzoic acid (4) and aspirochlorine (5) from L. ellipsoideum, and aszonalenin (6) and acetylaszonalenin (7) from Aspergillus sp. 2 (Figure 4).
Antimicrobial activity of fungal crude extracts against a set of human microbial pathogens.
| Species (isolate) | Pseudomonas aeruginosa ATCC 27853 | Bacillus spizizenii ATCC 6633 | Staphylococcus aureus ATCC 25923 | Escherichia coli ATCC 10536 | Salmonella typhi ATCC 33459 | Candida albicans ATCC 10231 |
|---|---|---|---|---|---|---|
| Aspergillus sp. 1 (A) | + | + | ||||
| Aspergillus sp. 1 (B) | + | + | ||||
| Zopfiella erostrate (C) | + | |||||
| Aspergillus cejpii (I) | + | +++ | + | + | ||
| Penicillium sp. 1 (M) | + | |||||
| Leiothecium ellipsoideum (O) | + | +++ | ||||
| Aspergillus cejpii (R) | + | +++ | +++ | |||
| Aspergillus cejpii (T) | + | +++ | +++ | |||
| Aspergillus sp. 2 (W) | ++++ | + | ||||
| Positive controls: Minimum inhibitory concentration (µg ml−1) |
6.3a |
7.8b |
0.1c |
3.1c |
0.8c |
20.3d |
-
Inhibition criteria: (++++) total inhibition at 200 μg ml−1 and partial inhibition at 20 μg ml−1; (+++) total inhibition at 200 μg ml−1 and no inhibition at 20 μg ml−1; and (+) partial inhibition only at 200 μg ml−1. Growth inhibition was visually assessed by turbidity. Positive controls: agentamicin, bvancomycin, campicillin, and dnystatin.
Chemical structures of the compounds isolated from Aspergillus cejpii (isolate I), Leiothecium ellipsoideum (isolate O), and Aspergillus sp. 2 (isolate W).
4 Discussion
Relatively little is known about fungi in deep-sea extreme ecosystems. In this study, we applied traditional culture-based methods to examine the taxonomic and chemical diversity of filamentous fungi in sediment samples of three hydrothermal vent areas and an oxygen minimum zone in the Gulf of California, Mexico. We were able to establish a fungal collection using a classic culture medium supplemented with sea salt at a pressure of 1 atm and 22 °C in accordance with the methodology of Le Calvez et al. (2009). As a result, 32 isolates were cultured and clustered into 14 OTUs identified by molecular analyses of ITS and benA, and morphology.
Globally, the majority of the described fungal species (∼98 %) are members of the clade Dikarya, which includes two phyla: Ascomycota and Basidiomycota. Within these, the Ascomycota is the largest phylum with Pezizomycotina as the largest subphylum (James et al. 2006). This pattern is also true for fungi reported from hydrothermal vents and OMZ (e.g. Burgaud et al. 2009; Le Calvez et al. 2009; Xu et al. 2017). Likewise, the high abundance of Eurotiomycetes (particularly members of Aspergillus and Penicillium), followed by Saccharomycetes, Dothideomycetes and Sordariomycetes in deep-sea environments has been extensively reported (reviewed by Nagano and Nagahama 2012), suggesting their ubiquity in the ocean. This resembles our findings on the high abundance of the Pezizomycotina representatives (Eurotiomycetes 84.2 %, Sordariomycetes 10.5 %, and Dothideomycetes 5.3 %).
The dominance of A. sydowii in PV (chimneys and mounds of calcite; Paduan et al. 2018) must be emphasized as this species has been repetitively recovered from deep-sea sediments (Damare and Raghukumar 2008; Kumar et al. 2021), the South Mid-Atlantic Ridge (Xu et al. 2017), animals from vents in Rainbow and Lost City sites within the Mid-Atlantic Ridge (carbonate-rich chimneys; Burgaud et al. 2009), fan corals (Alker et al. 2001), and even from a crab sampled in a shallow-water hydrothermal vent field in Taiwan (Pang et al. 2019). Recent evidence supports that this species plays a key role in vent trophic chains (Salcedo et al. 2023), is adapted to subseafloor sediment environments (Jiang et al. 2023), possesses spores with the ability to germinate at elevated hydrostatic pressures and low temperatures (Damare et al. 2006; Raghukumar et al. 2004), and is halo-dependent (Pang et al. 2020). So, it is feasible that this fungus is a common resident of deep-sea systems (reported as a pathogen of sea fan corals; Alker et al. 2001), occurring as an occasional pathogen of the macrofauna. However, this assumption remains to be confirmed.
At large, microbes in extreme environments do not necessarily require extreme culture conditions (Pettit 2011). However, fundamental constraints of culture-based methods tend to limit the understanding of fungal diversity in deep-sea extreme systems as isolates are not kept under in situ conditions (e.g. hydrostatic pressure, temperatures, nutrients, oxygen, etc.; discussed by Keeler et al. 2021). In this sense, our results complement previous culture-independent reports on the same samples using high-throughput Illumina sequencing of the ITS1 region, contributing with information on the occurrence of Aspergillus spp. in PV, FI and AV; L. ellipsoideum in FI; Penicillium miczynskii in ZM, PV and FI; P. brefeldianum in AV; Penicillium spp. in FI; and Z. erostrata in ZM (Velez et al. 2022). Both approaches provide valuable information on fungal communities and should be jointly considered when assessing diversity. In addition, our results on the fungal growth range agreed with former research evidencing that marine-derived isolates from shallow vents are able to grow at 25–50 °C (Guo et al. 2025), documenting their wide thermotolerance.
From the bioactivity-directed chemical study, seven known compounds were isolated and identified. Dimethylgliotoxin (1) isolated from A. cejpii (isolate I) in this work, was first reported from Glicocladium deliquescens in 1979 and recently from Aspergillus fumigatus and Penicillium terlikowskii (Afiyatullov et al. 2005). Biological activities reported for this compound include antibacterial against methicillin-resistant S. aureus (MRSA) with a minimum inhibitory concentration (MIC) value of 31.2 μg ml−1 (Li et al. 2006), antiparasitic against Trypanosoma brucei (inhibitory concentration 50, IC50 = 40.2 μM), and cytotoxic against P388 murine leukemia cells (CI50 = 0.11) (Sun et al. 2012). On the other hand, fiscalin C (2) and epi-fiscalin C (3), previously reported from Neosartorya spp. (Buttachon et al. 2012; Wong et al. 1993), exhibited weak cytotoxic activity against several human cell lines (Prata-Sena et al. 2016; Sawadsitang et al. 2015). Fiscalin C (2) also displayed a synergistic effect against MRSA when combined with oxacillin (Bessa et al. 2016).
3-Hydroxybenzoic acid (4) isolated from L. ellipsoideum (isolate O) was previously isolated from several fungal species, including Penicillium griseofulvum, Schizophyllum commune, Pestalotiopsis microspora, Diaporthe phaseolorum, and Fusarium proliferatum. This compound showed analgesic and antioxidant activities (Yao et al. 2016) and inhibited lipolysis in adipocytes through its agonist effect with the hydroxycarboxylic acid receptors HCA1 and HCA2 (Juurlink et al. 2014). Aspirochlorine (5), a chlorinated epidithiodiketopiperazine, was isolated from the same fungus. This compound possessed strong antifungal activity against azole-resistant C. albicans strains, antibacterial activity against S. aureus, and antiproliferative properties (Chankhamjon et al. 2014).
Finally, aszonalenin (6) and its acetylated derivative, acetylaszonalenin (7), isolated from Aspergillus sp. 2 (isolate W) and previously reported from Neosartorya fischeri and another species of Aspergillus, did not show antimicrobial activity. Acetylaszonalenin (7) inhibited the human receptor for neurokinin 1, which is involved in gastrointestinal disorders (Yin et al. 2009).
Even though no novel bioactive compounds were produced by the fungal isolates in this study, the results hint at the promising potential of these fungi in bioprospecting. Future exploratory works should thus consider the implementation of the “one strain, many compounds” (OSMAC) approach to trigger the expression of silent gene clusters, allowing the discovery of novel molecules (Romano et al. 2018). In this sense, the activation of inert biosynthetic pathways in fungi from hydrothermal vents was achieved by eliciting heavy metal stress (Ding et al. 2016; Ye et al. 2014). Likewise, fermentation under several temperature conditions has been proven to be an efficient strategy to promote the production of antimicrobial molecules in deep-sea fungal isolates (Villanueva-Silva et al. 2021). So, future investigations aiming to discover natural products from hydrothermal vent fungi should consider incorporating this stress-driven strategy (Jiang et al. 2014).
Ecologically important relationships between fungi and other organisms have been clearly demonstrated in marine hydrothermal vents (e.g. Burgaud et al. 2009; Shaumi et al. 2021) and less explored in OMZ. Former culture-independent studies in the PV, AV, FI, and ZM systems have revealed a taxonomically (Velez et al. 2022) and functionally (Salcedo et al. 2023) diverse fungal community, hinting at potential antagonistic roles based on FUNGuild and isotopic analyses. In this context, the prominent antimicrobial activity observed in our extracts, including species that target several pathogens (e.g. A. cejpii), suggests that the identified secondary metabolites could have important roles in antagonistic cross-kingdom interactions that ultimately affect ecosystem structure and function. However, much remains to be learned before these roles can be fully appreciated (Wietz et al. 2013). Also, it is important to investigate the physiology of the targeted fungal species and their extremotolerances towards temperature, and hydrostatic pressure to attain a better OSMAC experimental design.
5 Conclusions
Our findings demonstrated that culture-dependent approaches provide valuable information on fungal diversity and should be jointly considered when implementing culture-independent methodologies to attain a better understanding of fungal communities and to preserve ex situ valuable bioresources. This investigation confirmed that deep-sea extreme ecosystems, such as hydrothermal vents and OMZ, may serve as promising reservoirs of fungal genetic resources that produce valuable and potentially useful secondary metabolites. Future investigations in bioprospecting can focus on implementing stress-driven strategies coupled with the OSMAC approach (e.g. heavy metals and culturing temperatures) to trigger expression of silent gene clusters, favoring the discovery of novel molecules.
Funding source: DGAPA-PAPIIT-UNAM
Award Identifier / Grant number: IN200921
Award Identifier / Grant number: IN203923
About the authors
Dr. Patricia Velez earned her B.S. (2008), M.S. (2010), and Ph.D. (2014) degrees in Biological Sciences from the UNAM for her work on arenicolous marine fungi. Next, she performed two postdoctoral stays at the UNAM and the CICESE studying molecular ecology of freshwater and deep-sea fungi respectively. She is now a faculty member and full-time researcher at the Institute of Biology, UNAM where her work focuses on the exploration of fungal diversity, ecology, and potential utilization, particularly in marine ecosystems.
Dr. Jaime Gasca-Pineda is a postdoctoral researcher at the Ecology Institute in the National Autonomous University of Mexico (UNAM). He specializes in population genetics and bioinformatics. Currently, his work focuses on the evaluation of the genomic diversity of wild relatives of Mexican crops and the genomics of marine fungi.
Abril Hernandez-Monroy is a PhD student at the Biology Institute of the National Autonomous University of Mexico. Her research focuses on fungal-bacteria interactions from organisms isolated from deep-sea hydrothermal vents, a topic she has explored from various perspectives, including culturing and transcriptomics. Her doctoral work focuses on elucidating the molecular and phenotypic mechanisms underlying microbial adaptation to long-term interspecies interactions.
Dr. Mario Figueroa received his B.S. (2004), M.S. (2006), and Ph.D. (2009) degrees in Chemistry from UNAM under the mentorship of Professor Rachel Mata. After two postdoctoral stays at Lehman College, NY, and UNCG, NC, he returned to Facultad de Química, UNAM, where he became a full professor. His research focuses on the chemistry and biology of microbes from unexplored areas of Mexico. He has published over 65 peer-reviewed papers and 4 book chapters and is a co-inventor on three patents.
Acknowledgments
M.F. thanks CONAHCyT Apoyos Complementarios para Estancias Sabáticas Vinculadas a la Consolidación de Grupos de Investigación 2023, UNAM-DGAPA Programa de Apoyos para la Superación del Personal Académico (PASPA), and Fulbright-García Robles for the support received to pursue a research stay in the laboratory of the Distinguished Professor William Fenical at the Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, UCSD. We thank Robert Vrijenhoek and Luis A. Soto for facilitating access to the sediment samples; Lidia I. Cabrera Martínez and Andrea R. Jiménez Marín for technical support during molecular work at the Laboratorio de Biología Molecular (Instituto de Biología, UNAM); Laura M. Márquez Valdelamar and Nelly M. López Ortíz for their assistance during sequencing procedures at the Laboratorio de Secuenciación Genómica de la Biodiversidad (Instituto de Biología, UNAM); Berenit Mendoza-Garfias for technical guidance during SEM examinations (Instituto de Biología, UNAM). Rosa Isela del Villar and Nayeli López Balbiaux for collecting NMR spectra at the USAII (Facultad de Química, UNAM); Alejandro Camacho Cruz for providing the strains for the bioassay (Cepario, Facultad de Química, UNAM); and Ramiro del Carmen for their valuable computational support (Facultad de Química, UNAM). We thank the reviewers for their valuable comments on earlier versions of the manuscript.
-
Research ethics: Not applicable.
-
Informed consent: Not applicable.
-
Author contributions: All authors have accepted responsibility for the entire content of this manuscript and approved its submission. PV: framing hypothesis and experimental design; laboratory/field work; data analysis and interpretation; manuscript preparation; manuscript revision; funding obtention; JGP: data analysis and interpretation; manuscript revision; AHM: laboratory/field work; manuscript revision; MMH: laboratory/field work; AAR: laboratory/field work; MALL: laboratory/field work; MRG: laboratory/field work; DLS: laboratory/field work; manuscript revision; MF: framing hypothesis and experimental design; data analysis and interpretation; manuscript revision.
-
Use of Large Language Models, AI and Machine Learning Tools: None declared.
-
Conflict of interest: The authors state no conflict of interest.
-
Research funding: This research work was financially supported by DGAPA-PAPIIT-UNAM IN200921 (PV) and IN203923 (MF).
-
Data availability: Sequence data are available at NCBI under the following accession numbers:
| PP955440 | PQ304794 |
| PP955440 | PQ304793 |
| PP955441 | PQ304795 |
| PP955439 | PQ304790 |
| PP955443 | PQ304782 |
| PP955443 | PQ304782 |
| PP955442 | PQ304788 |
| PP955438 | PQ304787 |
| PP955449 | PQ304784 |
| PP955444 | PQ304789 |
| PP955444 | PQ304789 |
| PP955444 | PQ304789 |
| PP955444 | PQ304789 |
| PP955444 | PQ304789 |
| PP955444 | PQ304789 |
| PP955446 | PQ304792 |
| PP955442 | PQ304788 |
| PQ304791 | |
| PP955447 | PQ304781 |
| PP955442 | PQ304788 |
| PP955450 | PQ304783 |
| PP955444 | PQ304789 |
| PP955449 | PQ304784 |
| PP955437 | |
| PP955448 | PQ304785 |
| PP955448 | PQ304785 |
| PP955448 | PQ304785 |
| PP955448 | PQ304785 |
| PP955445 | PQ304787 |
| PP955441 | PQ304795 |
| PP955436 | PQ304786 |
| PP955443 | PQ304782 |
References
Afiyatullov, S.S., Kalinovskii, A.I., Pivkin, M.V., Dmitrenok, P.S., and Kuznetsova, T.A. (2005). Alkaloids from the marine isolate of the fungus Aspergillus fumigatus. Chem. Nat. Compd. 41: 236–238, https://doi.org/10.1007/s10600-005-0122-y.Search in Google Scholar
Alker, A.P., Smith, G.W., and Kim, K. (2001). Characterization of Aspergillus sydowii (Thom et Church), a fungal pathogen of Caribbean Sea fan corals. Hydrobiologia 460: 105–111, https://doi.org/10.1007/978-94-017-3284-0_9.Search in Google Scholar
Barone, G., Varrella, S., Tangherlini, M., Rastelli, E., Dell’Anno, A., Danovaro, R., and Corinaldesi, C. (2019). Marine fungi: biotechnological perspectives from deep-hypersaline anoxic basins. Diversity 11: 113, https://doi.org/10.3390/d11070113.Search in Google Scholar
Bessa, L.J., Buttachon, S., Dethoup, T., Martins, R., Vasconcelos, V., Kijjoa, A., and Martins da Costa, P. (2016). Neofiscalin A and fiscalin C are potential novel indole alkaloid alternatives for the treatment of multidrug-resistant gram-positive bacterial infections. FEMS Microbiol. Lett. 363: fnw150, https://doi.org/10.1093/femsle/fnw150.Search in Google Scholar PubMed
Blöthe, M., Wegorzewski, A., Müller, C., Simon, F., Kuhn, T., and Schippers, A. (2015). Manganese-cycling microbial communities inside deep-sea manganese nodules. Environ. Sci. Technol. 49: 7692–7700, https://doi.org/10.1021/es504930v.Search in Google Scholar PubMed
Burgaud, G., Arzur, D., Durand, L., Cambon-Bonavita, M.A., and Barbier, G. (2010). Marine culturable yeasts in deep-sea hydrothermal vents: species richness and association with fauna. FEMS Microbiol. Ecol. 73: 121–133, https://doi.org/10.1111/j.1574-6941.2010.00881.x.Search in Google Scholar PubMed
Burgaud, G., Arzur, D., Sampaio, J.P., and Barbier, G. (2011). Candida oceani sp. nov., novel yeast isolated from a Mid-Atlantic Ridge hydrothermal vent (−2300 meters). Antonie Leeuwenhoek 100: 75–82, https://doi.org/10.1007/s10482-011-9566-1.Search in Google Scholar PubMed
Burgaud, G., Coton, M., Jacques, N., Debaets, S., Maciel, N.O.P., Rosa, C.A., Gadanho, M., Sampaio, J.P., and Casaregola, S. (2016). Yamadazyma Barbieri f.a. sp. nov., an ascomycetous anamorphic yeast isolated from a Mid-Atlantic Ridge hydrothermal site (−2300 m) and marine coastal waters. Int. J. Syst. Evol. Microbiol. 66: 3600–3606, https://doi.org/10.1099/ijsem.0.001239.Search in Google Scholar PubMed
Burgaud, G., Le Calvez, T., Arzur, D., Vandenkoornhuyse, P., and Barbier, G. (2009). Diversity of culturable marine filamentous fungi from deep-sea hydrothermal vents. Environ. Microbiol. 11: 1588–1600, https://doi.org/10.1111/j.1462-2920.2009.01886.x.Search in Google Scholar PubMed
Buttachon, S., Chandrapatya, A., Manoch, L., Silva, A., Gales, L., Bruyère, C., Kiss, R., and Kijjoa, A. (2012). Sartorymesin, a new indole alkaloid, and new analogues of tryptoquivaline and fiscalins produced by Neosartorya siamensis (KUFC 6349). Tetrahedron 68: 3253–3262, https://doi.org/10.1016/j.tet.2012.02.024.Search in Google Scholar
Chankhamjon, P., Boettger-Schmidt, D., Scherlach, K., Urbansky, B., Lackner, G., Kalb, D., Dahse, H.M., Hoffmeister, D., and Hertweck, C. (2014). Biosynthesis of the halogenated mycotoxin aspirochlorine in Koji mold involves a cryptic amino acid conversion. Angew Chem. Int. Ed. Engl. 53: 13409–13413, https://doi.org/10.1002/anie.201407624.Search in Google Scholar PubMed
Clague, D.A., Caress, D.W., Dreyer, B.M., Lundsten, L., Paduan, J.B., Portner, R.A., Spelz-Madero, R., Bowles, J.A., Castillo, P.R., Guardado-France, R., et al.. (2018). Geology of the Alarcon Rise, southern Gulf of California. Geochem. Geophys. Geosyst. 19: 807–837, https://doi.org/10.1002/2017gc007348.Search in Google Scholar
Damare, S. and Raghukumar, C. (2008). Fungi and macroaggregation in deep-sea sediments. Microb. Ecol. 56: 168–177, https://doi.org/10.1007/s00248-007-9334-y.Search in Google Scholar PubMed
Damare, S., Raghukumar, C., and Raghukumar, S. (2006). Fungi in deep-sea sediments of the Central Indian Basin. Deep-Sea Res. I: Oceanogr. Res. Pap. 53: 14–27, https://doi.org/10.1016/j.dsr.2005.09.005.Search in Google Scholar
Darriba, D., Taboada, G.L., Doallo, R., and Posada, D. (2012). jModelTest 2: more models, new heuristics and parallel computing. Nat. Methods 9: 772, https://doi.org/10.1038/nmeth.2109.Search in Google Scholar PubMed PubMed Central
Dekov, V.M., Bindi, L., Burgaud, G., Petersen, S., Asael, D., Rédou, V., Fouquet, Y., and Pracejus, B. (2013). Inorganic and biogenic As-sulfide precipitation at seafloor hydrothermal fields. Mar. Geol. 342: 28–38, https://doi.org/10.1016/j.margeo.2013.06.006.Search in Google Scholar
Demain, A.L. (2014). Importance of microbial natural products and the need to revitalize their discovery. J. Ind. Microbiol. Biotechnol. 41: 185–201, https://doi.org/10.1007/s10295-013-1325-z.Search in Google Scholar PubMed
Dick, G.J. (2019). The microbiomes of deep-sea hydrothermal vents: distributed globally, shaped locally. Nat. Rev. Microbiol. 17: 271–283, https://doi.org/10.1038/s41579-019-0160-2.Search in Google Scholar PubMed
Ding, C., Wu, X., Auckloo, B.N., Chen, C.T.A., Ye, Y., Wang, K., and Wu, B. (2016). An unusual stress metabolite from a hydrothermal vent fungus Aspergillus sp. WU 243 induced by cobalt. Molecules 21: 105, https://doi.org/10.3390/molecules21010105.Search in Google Scholar PubMed PubMed Central
Doyle, J.J. and Doyle, J.L. (1987). A rapid DNA isolation procedure for small quantities of fresh leaf tissue. Phytochem. Bull. 19: 11–15.Search in Google Scholar
Edgar, R.C. (2004). MUSCLE: multiple sequence alignment with high accuracy and high throughput. Nucleic Acids Res. 32. 1792–1797.10.1093/nar/gkh340Search in Google Scholar PubMed PubMed Central
Edgcomb, V.P., Bernhard, J.M., and Jeon, S. (2007). Deep-sea microbial eukaryotes in anoxic, microoxic, and sulfidic environments. In: Seckbach, J. (Ed.), Algae and cyanobacteria in extreme environments. Cellular origin, life in extreme habitats and astrobiology, Vol. 11. Springer, Dordrecht, pp. 711–734.10.1007/978-1-4020-6112-7_39Search in Google Scholar
Ewing, B. and Green, P. (1998). Base-calling of automated sequencer traces using phred. II. Error probabilities. Genome Res. 8: 186–194, https://doi.org/10.1101/gr.8.3.186.Search in Google Scholar
Ewing, B., Hillier, L., Wendl, M., and Green, P. (1998). Base-calling of automated sequencer traces using phred. I. Accuracy assessment. Genome Res. 8: 175–185, https://doi.org/10.1101/gr.8.3.175.Search in Google Scholar PubMed
Geller-McGrath, D., Mara, P., Taylor, G.T., Suter, E., Edgcomb, V., and Pachiadaki, M. (2023). Diverse secondary metabolites are expressed in particle-associated and free-living microorganisms of the permanently anoxic Cariaco Basin. Nat. Commun. 14: 656, https://doi.org/10.1038/s41467-023-36026-w.Search in Google Scholar PubMed PubMed Central
Gilly, W.F., Beman, J.M., Litvin, S.Y., and Robison, B.H. (2013). Oceanographic and biological effects of shoaling of the oxygen minimum zone. Ann. Rev. Mar. Sci. 5: 393–420, https://doi.org/10.1146/annurev-marine-120710-100849.Search in Google Scholar PubMed
Glass, N.L. and Donaldson, G.C. (1995). Development of primer sets designed for use with the PCR to amplify conserved genes from filamentous ascomycetes. Appl. Environ. Microbiol. 61: 1323–1330, https://doi.org/10.1128/aem.61.4.1323-1330.1995.Search in Google Scholar PubMed PubMed Central
Gordon, D., Desmarais, C., and Green, P. (2001). Automated finishing with autofinish. Genome Res. 11: 614–625, https://doi.org/10.1101/gr.171401.Search in Google Scholar PubMed PubMed Central
Guindon, S. and Gascuel, O. (2003). A simple, fast, and accurate algorithm to estimate large phylogenies by maximum likelihood. Syst. Biol. 52: 696–704, https://doi.org/10.1080/10635150390235520.Search in Google Scholar PubMed
Guo, S.Y., Chiang, M.W.L., Lin, W.R., Hsieh, S.Y., Phatthongkleang, T., Jones, E.B.G., and Pang, K.L. (2025). Similarity in growth response of Aspergillus terreus isolates under mimic hydrothermal vent conditions suggests no physiological growth barrier between terrestrial and marine environments. Bot. Mar. 68: 133–142, https://doi.org/10.1515/bot-2024-0070.Search in Google Scholar
Herring, P.J. (2001). The biology of the deep ocean. Oxford University Press, Oxford.10.1093/oso/9780198549567.001.0001Search in Google Scholar
Hutchins, D.A. and Capone, D.G. (2022). The marine nitrogen cycle: new developments and global change. Nat. Rev. Microbiol. 20: 401–414, https://doi.org/10.1038/s41579-022-00687-z.Search in Google Scholar PubMed
Inostroza, A., Lara, L., Paz, C., Perez, A., Galleguillos, F., Hernandez, V., Becerra, J., González-Rocha, G., and Silva, M. (2018). Antibiotic activity of emerimicin IV isolated from Emericellopsis minima from Talcahuano Bay, Chile. Nat. Prod. Res. 32: 1361–1364, https://doi.org/10.1080/14786419.2017.1344655.Search in Google Scholar PubMed
James, T.Y., Kauff, F., Schoch, C.L., Matheny, P.B., Hofstetter, V., Cox, C.J., Vilgalys, R., Gueidan, C., Fraker, E., Miadlikowska, J., et al.. (2006). Reconstructing the early evolution of fungi using a six-gene phylogeny. Nature 443: 818–822, https://doi.org/10.1038/nature05110.Search in Google Scholar PubMed
Jannasch, H.W. and Mottl, M.J. (1985). Geomicrobiology of deep-sea hydrothermal vents. Science 229: 717–725, https://doi.org/10.1126/science.229.4715.717.Search in Google Scholar PubMed
Jiang, J.P., Liu, X., Liao, Y.F., Shan, J., Zhu, Y.P., and Liu, C.H. (2023). Genomic insights into Aspergillus sydowii 29R-4-F02: unraveling adaptive mechanisms in subseafloor coal-bearing sediment environments. Front. Microbiol. 14: 1216714, https://doi.org/10.3389/fmicb.2023.1216714.Search in Google Scholar PubMed PubMed Central
Jiang, W., Ye, P., Chen, C.T.A., Wang, K., Liu, P., He, S., Wu, X., Gan, L., Ye, Y., and Wu, B. (2013). Two novel hepatocellular carcinoma cycle inhibitory cyclodepsipeptides from a hydrothermal vent crab-associated fungus Aspergillus clavatus C2Wu. Mar. Drugs 11: 4761–4772, https://doi.org/10.3390/md11124761.Search in Google Scholar PubMed PubMed Central
Jiang, W., Zhong, Y., Shen, L., Wu, X., Ye, Y., Chen, C.T.A., and Wu, B. (2014). Stress-driven discovery of natural products from extreme marine environment-Kueishantao hydrothermal vent, a case study of metal switch valve. Curr. Org. Chem. 18: 925–934, https://doi.org/10.2174/138527281807140515155705.Search in Google Scholar
Juurlink, B.H.J., Azouz, H.J., Aldalati, A.M.Z., AlTinawi, B.M.H., and Ganguly, P. (2014). Hydroxybenzoic acid isomers and the cardiovascular system. Nutr. J. 13: 63, https://doi.org/10.1186/1475-2891-13-63.Search in Google Scholar PubMed PubMed Central
Kalyaanamoorthy, S., Minh, B.Q., Wong, T.K.F., von Haeseler, A., and Jermiin, L.S. (2017). ModelFinder: fast model selection for accurate phylogenetic estimates. Nat. Methods 14: 587–589, https://doi.org/10.1038/nmeth.4285.Search in Google Scholar PubMed PubMed Central
Karstensen, J., Stramma, L., and Visbeck, M. (2008). Oxygen minimum zones in the eastern tropical Atlantic and Pacific oceans. Prog. Oceanogr. 77: 331–350, https://doi.org/10.1016/j.pocean.2007.05.009.Search in Google Scholar
Keeler, E., Burgaud, G., Teske, A., Beaudoin, D., Mehiri, M., Dayras, M., Cassand, J., and Edgcomb, V. (2021). Deep-sea hydrothermal vent sediments reveal diverse fungi with antibacterial activities. FEMS Microbiol. Ecol. 97: fiab103, https://doi.org/10.1093/femsec/fiab103.Search in Google Scholar PubMed
Kelley, D.S., Karson, J.A., Blackman, D.K., Früh-Green, G.L., Butterfield, D.A., Lilley, M.D., Olson, E.J., Schrenk, M.O., Roe, K.K., Lebon, G.T., et al.. (2001). An off-axis hydrothermal vent field near the Mid-Atlantic Ridge at 30° N. Nature 412: 145–149, https://doi.org/10.1038/35084000.Search in Google Scholar PubMed
Kumar, A.G., Manisha, D., Sujitha, K., Magesh Peter, D., Kirubagaran, R., and Dharani, G. (2021). Genome sequence analysis of deep sea Aspergillus sydowii BOBA1 and effect of high pressure on biodegradation of spent engine oil. Sci. Rep. 11: 9347, https://doi.org/10.1038/s41598-021-88525-9.Search in Google Scholar PubMed PubMed Central
Lai, C., Chen, J., Liu, J., Tian, D., Lan, D., Liu, T., Wu, B., Bi, H., and Tang, J. (2022). New polyketides from a hydrothermal vent sediment fungus Trichoderma sp. JWM29-10-1 and their antimicrobial effects. Mar. Drugs 20: 720, https://doi.org/10.3390/md20110720.Search in Google Scholar PubMed PubMed Central
Le Calvez, T., Burgaud, G., Mahé, S., Barbier, G., and Vandenkoornhuyse, P. (2009). Fungal diversity in deep-sea hydrothermal ecosystems. Appl. Environ. Microbiol. 75: 6415–6421, https://doi.org/10.1128/aem.00653-09.Search in Google Scholar PubMed PubMed Central
Levin, L.A., Baco, A.R., Bowden, D.A., Colaco, A., Cordes, E.E., Cunha, M.R., Demopoulos, A.W.J., Gobin, J., Grupe, B.M., Le, J., et al.. (2016). Hydrothermal vents and methane seeps: rethinking the sphere of influence. Front. Mar. Sci. 3: 72, https://doi.org/10.3389/fmars.2016.00072.Search in Google Scholar
Li, X., Kim, S.K., Nam, K.W., Kang, J.S., Choi, H.D., and Son, B.W. (2006). A new antibacterial dioxopiperazine alkaloid related to gliotoxin from a marine isolate of the fungus Pseudallescheria. J. Antibiot. 59: 248–250, https://doi.org/10.1038/ja.2006.35.Search in Google Scholar PubMed
Manohar, C.S., Menezes, L.D., Ramasamy, K.P., and Meena, R.M. (2015). Phylogenetic analyses and nitrate-reducing activity of fungal cultures isolated from the permanent, oceanic oxygen minimum zone of the Arabian Sea. Can. J. Microbiol. 61: 217–226, https://doi.org/10.1139/cjm-2014-0507.Search in Google Scholar PubMed
Millberg, H., Boberg, J., and Stenlid, J. (2015). Changes in fungal community of Scots pine (Pinus sylvestris) needles along a latitudinal gradient in Sweden. Fungal Ecol. 17: 126–139, https://doi.org/10.1016/j.funeco.2015.05.012.Search in Google Scholar
Minh, B.Q., Schmidt, H.A., Chernomor, O., Schrempf, D., Woodhams, M.D., Von Haeseler, A., and Lanfear, R. (2020). IQ-TREE 2: new models and efficient methods for phylogenetic inference in the genomic era. Mol. Biol. Evol. 37: 2461, https://doi.org/10.1093/molbev/msaa015.Search in Google Scholar PubMed PubMed Central
Nagano, Y. and Nagahama, T. (2012). Fungal diversity in deep-sea extreme environments. Fungal Ecol. 5: 463–471, https://doi.org/10.1016/j.funeco.2012.01.004.Search in Google Scholar
Paduan, J.B., Zierenberg, R.A., Clague, D.A., Spelz, R.M., Caress, D.W., Troni, G., Thomas, H., Glessner, J., Lilley, M.D., Lorenson, T., et al.. (2018). Discovery of hydrothermal vent fields on Alarcón Rise and in Southern Pescadero Basin, Gulf of California. Geochem. Geophys. Geosyst. 19: 4788–4819, https://doi.org/10.1029/2018gc007771.Search in Google Scholar
Pan, C., Shi, Y., Auckloo, B.N., Chen, X., Chen, C.T.A., Tao, X., and Wu, B. (2016). An unusual conformational isomer of verrucosidin backbone from a hydrothermal vent fungus, Penicillium sp. Y-50-10. Mar. Drugs 14: 156, https://doi.org/10.3390/md14080156.Search in Google Scholar PubMed PubMed Central
Pan, C., Shi, Y., Auckloo, B.N., Chen, C.T.A., Chen, X., Wu, X., and Wu, B. (2018). Four verrucosidin derivatives isolated from the hydrothermal vent sulfur-derived fungus Penicillium sp. Y-50-10. Chem. Nat. Compd. 54: 253–256, https://doi.org/10.1007/s10600-018-2316-0.Search in Google Scholar
Pan, C., Shi, Y., Nazia, B., Shams, S., Akhter, N., Wang, K., Ye, Y., Arthur, C., Tao, X., and Wu, B. (2017). Isolation and antibiotic screening of fungi from a hydrothermal vent site and characterization of secondary metabolites from a Penicillium isolate. Mar. Biotechnol. 19: 469–497.10.1007/s10126-017-9765-5Search in Google Scholar PubMed
Pang, K.L., Chiang, M.W.L., Guo, S.Y., Shih, C.Y., Dahms, H.U., Hwang, J.S., and Cha, H.J. (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 15: e0233621, https://doi.org/10.1371/journal.pone.0233621.Search in Google Scholar PubMed PubMed Central
Pang, K.L., Guo, S.Y., Chen, I.A., Burgaud, G., Luo, Z.H., Dahms, H.U., Hwang, J.S., Lin, Y.L., Huang, J.S., Ho, T.W., et al.. (2019). Insights into fungal diversity of a shallow-water hydrothermal vent field at Kueishan Island, Taiwan by culture-based and metabarcoding analyses. PLoS One 14: e0226616, https://doi.org/10.1371/journal.pone.0226616.Search in Google Scholar PubMed PubMed Central
Paulus, E. (2021). Shedding light on deep-sea biodiversity: a highly vulnerable habitat in the face of anthropogenic change. Front. Mar. Sci. 8: 667048, https://doi.org/10.3389/fmars.2021.667048.Search in Google Scholar
Peng, X. and Valentine, D.L. (2021). Diversity and N2O production potential of fungi in an oceanic oxygen minimum zone. J. Fungi 7: 218, https://doi.org/10.3390/jof7030218.Search in Google Scholar PubMed PubMed Central
Persoh, D., Melcher, M., Flessa, F., and Rambold, G. (2010). First fungal community analyses of endophytic ascomycetes associated with Viscum album ssp. austriacum and its host Pinus sylvestris. Fungal Biol. 114: 585–596, https://doi.org/10.1016/j.funbio.2010.04.009.Search in Google Scholar PubMed
Pettit, R.K. (2011). Culturability and secondary metabolite diversity of extreme microbes: expanding contribution of deep sea and deep-sea vent microbes to natural product discovery. Mar. Biotechnol. 13: 1–11, https://doi.org/10.1007/s10126-010-9294-y.Search in Google Scholar PubMed
Prata-Sena, M., Ramos, A.A., Buttachon, S., Castro-Carvalho, B., Marques, P., Dethoup, T., Kijjoa, A., and Rocha, E. (2016). Cytotoxic activity of secondary metabolites from marine-derived fungus Neosartorya siamensis in human cancer cells. Phytother. Res. 30: 1–10, https://doi.org/10.1002/ptr.5696.Search in Google Scholar PubMed
Raghukumar, C., Raghukumar, S., Sheelu, G., Gupta, S.M., Nath, B.N., and Rao, B.R. (2004). Buried in time: culturable fungi in a deep-sea sediment core from the Chagos Trench, Indian Ocean. Deep-Sea Res. I: Oceanogr. Res. Pap. 51: 1759–1768, https://doi.org/10.1016/s0967-0637(04)00151-7.Search in Google Scholar
Rambaut, A. and Drummond, A.J. (2018). Molecular evolution, phylogenetics and epidemiology. FigTree 1: 4.Search in Google Scholar
Rambaut, A., Drummond, A.J., Xie, D., Baele, G., and Suchard, M.A. (2018). Posterior summarization in Bayesian phylogenetics using Tracer 1.7. Syst. Biol. 67: 901–904, https://doi.org/10.1093/sysbio/syy032.Search in Google Scholar PubMed PubMed Central
Romano, S., Jackson, S.A., Patry, S., and Dobson, A.D. (2018). Extending the “one strain many compounds” (OSMAC) principle to marine microorganisms. Mar. Drugs 16: 244, https://doi.org/10.3390/md16070244.Search in Google Scholar PubMed PubMed Central
Salcedo, D.L., Velez, P., Hernandez-Monroy, A., and Soto, L.A. (2023). Insights into the functional role of fungi in deep-sea hydrothermal vents through the analysis of stable isotopes of carbon, nitrogen, and sulfur. Fungal Ecol. 64: 101250, https://doi.org/10.1016/j.funeco.2023.101250.Search in Google Scholar
Sawadsitang, S., Mongkolthanaruk, W., Suwannasai, N., and Sodngam, S. (2015). Antimalarial and cytotoxic constituents of Xylaria cf. cubensis PK108. Nat. Prod. Res. 29: 1–4, https://doi.org/10.1080/14786419.2015.1017724.Search in Google Scholar PubMed
Schneider, C.A., Rasband, W.S., and Eliceiri, K.W. (2012). NIH Image to ImageJ: 25 years of image analysis. Nat. Methods 9: 671–675, https://doi.org/10.1038/nmeth.2089.Search in Google Scholar PubMed PubMed Central
Shaumi, A., Cheang, U.C., Yang, C.Y., Chang, C.W., Guo, S.Y., Yang, C.H., Chan, T.Y., and Pang, K.L. (2021). Culturable fungi associated with the marine shallow-water hydrothermal vent crab Xenograpsus testudinatus at Kueishan Island, Taiwan. Bot. Mar. 64: 289–300, https://doi.org/10.1515/bot-2021-0034.Search in Google Scholar
Suchard, M.A., Lemey, P., Baele, G., Ayres, D.L., Drummond, A.J., and Rambaut, A. (2018). Bayesian phylogenetic and phylodynamic data integration using BEAST 1.10. Virus Evol. 4: vey016, https://doi.org/10.1093/ve/vey016.Search in Google Scholar PubMed PubMed Central
Sun, Y., Takada, K., Takemoto, Y., Yoshida, M., Nogi, Y., Okada, S., and Matsunaga, S. (2012). Gliotoxin analogues from a marine-derived fungus, Penicillium sp., and their cytotoxic and histone methyltransferase inhibitory activities. J. Nat. Prod. 75: 111–114, https://doi.org/10.1021/np200740e.Search in Google Scholar PubMed
Tao, Q., Ding, C., Nazia, B., and Wu, B. (2018). Bioactive metabolites from a hydrothermal vent fungus Aspergillus sp. YQ-13. Nat. Prod. Commun. 13: 571–573, https://doi.org/10.1177/1934578x1801300514.Search in Google Scholar
Tyler, P.A. (2003). Ecosystems of the deep oceans ecosystems of the world. Elsevier, Amsterdam.Search in Google Scholar
Velez, P., Salcedo, D.L., Espinosa-Asuar, L., Gasca-Pineda, J., Hernández-Monroy, A., and Soto, G.A. (2022). Fungal diversity in sediments from deep-sea extreme ecosystems in the southern Gulf of California, Mexico: insights into low- and high-temperature hydrothermal vents, and oxygen minimum zones. Front. Mar. Sci. 9: 802634, https://doi.org/10.3389/fmars.2022.802634.Search in Google Scholar
Villanueva-Silva, R., Velez, P., Riquelme, M., Fajardo-Hernández, C.A., Martínez-Cárdenas, A., Arista-Romero, A., Wan, B., Ma, R., Qader, M., Franzblau, S.G., et al.. (2021). Chemical diversity and antimicrobial potential of cultivable fungi from deep-sea sediments of the Gulf of Mexico. Molecules 26: 7328, https://doi.org/10.3390/molecules26237328.Search in Google Scholar PubMed PubMed Central
Warcup, J.H. (1950). The soil-plate method for isolation of fungi from soil. Nature 166: 117–118, https://doi.org/10.1038/166117b0.Search in Google Scholar PubMed
White, T.J., Bruns, T., Lee, S., and Taylor, J.W. (1990). Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. In: Innis, M.A., Gelfand, D.H., Sninsky, J.J., and White, T.J. (Eds.). PCR protocols: a guide to methods and applications. Academic Press, Cambridge, MA, pp. 315–322.10.1016/B978-0-12-372180-8.50042-1Search in Google Scholar
Wietz, M., Duncan, K., Patin, N.V., and Jensen, P.R. (2013). Antagonistic interactions mediated by marine bacteria: the role of small molecules. J. Chem. Ecol. 39: 879–891, https://doi.org/10.1007/s10886-013-0316-x.Search in Google Scholar PubMed
Wong, S., Musza, L., Kydd, G., Kulling, R., Gillum, A., and Cooper, R. (1993). Fiscalins: new substance P inhibitors produced by the fungus Neosartorya fischeri. J. Antibiot. 46: 545–553, https://doi.org/10.7164/antibiotics.46.545.Search in Google Scholar PubMed
Wright, J.J., Konwar, K.M., and Hallam, S.J. (2012). Microbial ecology of expanding oxygen minimum zones. Nat. Rev. Microbiol. 10: 381–394, https://doi.org/10.1038/nrmicro2778.Search in Google Scholar PubMed
Xu, W., Gong, L.F., Pang, K.L., and Luo, Z.H. (2018). Fungal diversity in deep-sea sediments of a hydrothermal vent system in the Southwest Indian Ridge. Deep-Sea Res. I: Oceanogr. Res. Pap. 131: 16–26, https://doi.org/10.1016/j.dsr.2017.11.001.Search in Google Scholar
Xu, W., Guo, S., Pang, K.L., and Luo, Z.H. (2017). Fungi associated with chimney and sulfide samples from a South Mid-Atlantic Ridge hydrothermal site: distribution, diversity and abundance. Deep-Sea Res. I: Oceanogr. Res. Pap. 123: 48–55, https://doi.org/10.1016/j.dsr.2017.03.004.Search in Google Scholar
Yao, H.M., Wang, G., Liu, Y.P., Rong, M.Q., Shen, C.B., Yan, X.W., Luo, X.D., and Lai, R. (2016). Phenolic acids isolated from the fungus Schizophyllum commune exert analgesic activity by inhibiting voltage-gated sodium channels. Chin. J. Nat. Med. 14: 661–670, https://doi.org/10.1016/s1875-5364(16)30078-4.Search in Google Scholar
Ye, P., Shen, L., Jiang, W., Ye, Y., Chen, C.T.A., Wu, X., Wang, K., and Wu, B. (2014). Zn-driven discovery of a hydrothermal vent fungal metabolite clavatustide C, and an experimental study of the anti-cancer mechanism of clavatustide B. Mar. Drugs 12: 3203–3217, https://doi.org/10.3390/md12063203.Search in Google Scholar PubMed PubMed Central
Yeverino, I.R., Bocanegra Sosa, T.P., Aguilar-Vega, L., García-Contreras, R., Magaña-González, J.L., and Figueroa, M. (2025). New antimicrobial cyclodepsipeptides from a freshwater fungus from the Sierra Madre Oriental in Mexico. ACS Omega 10: 5087–5096, https://doi.org/10.1021/acsomega.4c10990.Search in Google Scholar PubMed PubMed Central
Yin, W.B., Grundmann, A., Cheng, J., and Li, S.M. (2009). Acetylaszonalenin biosynthesis in Neosartorya fischeri. Identification of the biosynthetic gene cluster by genomic mining and functional proof of the genes by biochemical investigation. J. Biol. Chem. 284: 100–109, https://doi.org/10.1074/jbc.m807606200.Search in Google Scholar PubMed
Zheng, R., Cai, R., Liu, R., Liu, G., and Sun, C. (2021). Maribellus comscasis sp. nov., a novel deep-sea Bacteroidetes bacterium, possessing a prominent capability of degrading cellulose. Environ. Microbiol. 23: 4561–4575, https://doi.org/10.1111/1462-2920.15650.Search in Google Scholar PubMed
Supplementary Material
This article contains supplementary material (https://doi.org/10.1515/bot-2024-0106).
© 2025 the author(s), published by De Gruyter, Berlin/Boston
This work is licensed under the Creative Commons Attribution 4.0 International License.
Articles in the same Issue
- Frontmatter
- In this issue
- Physiology and Ecology
- Labelling kelps with 13C and 15N for isotope tracing or enrichment experiments
- Effects of thermal history on the heat shock response of bull kelp (Nereocystis luetkeana)
- Naturally occurring protoplasts in two Ulva spp. reveal a previously underestimated proliferation process
- Taxonomy/Phylogeny and Biogeography
- Unveiling Cladophora (Cladophorales, Chlorophyta) diversity in Turkey through DNA barcoding
- A new crustose brown alga, Endoplura geojensis sp. nov. (Ralfsiales, Phaeophyceae) from Korea based on molecular and morphological analyses
- Diversity of turf-forming Gelidium species growing on subtidal crustose coralline algae in the East Sea of Korea with a description of G. cristatum sp. nov.
- First record of the diatom pathogen Diatomophthora perforans cf. subsp. pleurosigmae (Oomycota) from the Mediterranean microphytobenthos
- Staminate flowers of the non-native seagrass, Halophila stipulacea, observed for the first time in Biscayne Bay, Florida, USA
- Chemistry and Applications
- Chemical and biological potential of fungi from deep-sea hydrothermal vents and an oxygen minimum zone
Articles in the same Issue
- Frontmatter
- In this issue
- Physiology and Ecology
- Labelling kelps with 13C and 15N for isotope tracing or enrichment experiments
- Effects of thermal history on the heat shock response of bull kelp (Nereocystis luetkeana)
- Naturally occurring protoplasts in two Ulva spp. reveal a previously underestimated proliferation process
- Taxonomy/Phylogeny and Biogeography
- Unveiling Cladophora (Cladophorales, Chlorophyta) diversity in Turkey through DNA barcoding
- A new crustose brown alga, Endoplura geojensis sp. nov. (Ralfsiales, Phaeophyceae) from Korea based on molecular and morphological analyses
- Diversity of turf-forming Gelidium species growing on subtidal crustose coralline algae in the East Sea of Korea with a description of G. cristatum sp. nov.
- First record of the diatom pathogen Diatomophthora perforans cf. subsp. pleurosigmae (Oomycota) from the Mediterranean microphytobenthos
- Staminate flowers of the non-native seagrass, Halophila stipulacea, observed for the first time in Biscayne Bay, Florida, USA
- Chemistry and Applications
- Chemical and biological potential of fungi from deep-sea hydrothermal vents and an oxygen minimum zone
