Diversity of Marine Macro-Algicolous Endophytic Fungi and Cytotoxic Potential of Biscogniauxia petrensis Metabolites Against Cancer Cell Lines

Marine seaweed endophytic fungi-derived active metabolites promote reactive oxygen species-induced cell cycle arrest and apoptosis in human breast cancer cells

BACKGROUND

Endophytic fungi have an abundant sources rich source of rich bioactive molecules with pivotal pharmacological properties. Several studies have found that endophytic fungi-derived bioactive secondary metabolites have antiproliferative, anti-oxidant, and anti-inflammatory properties, but the molecular mechanism by which they induce cell cycle arrest and apoptosis pathways is unknown. This study aimed to determine the molecular mechanism underlying the anticancer property of the endophytic fungi derived active secondary metabolites on human breast cancer cells.

METHODS

In this study, we identified four endophytic fungi from marine seaweeds and partially screened its phytochemical properties by Chromatography-Mass Spectrometry (GC-MS) analysis. Moreover, the molecular mechanism underlying the anticancer property of these active secondary metabolites (FA, FB, FC and FE) on human breast cancer cells were examined on MCF-7 cells by TT assay, Apoptotic assay by Acridine orang/Ethidium Bromide (Dual Staining), DNA Fragmentation by DAPI Staining, reactive oxygen species (ROS) determination by DCFH-DA assay, Cell cycle analysis was conducted Flow cytometry and the apoptotic signalling pathway was evaluated by westernblot analysis. Doxorubicin was used as a positive control drug for this experiment.

RESULTS

The GC-MS analysis of ethyl acetate extract of endophytic fungi from the marine macro-algae revealed the different functional groups and bioactive secondary metabolites. From the library, we observed the FC (76%), FB (75%), FA (73%) and FE (71%) have high level of antioxidant activity which was assessed by DPPH scavenging assay. Further, we evaluated the cytotoxic potentials of these secondary metabolites on human breast cancer MCF-7 cells for 24 h and the IC50 value were calculated (FA:28.62 ± 0.3 µg/ml, FB:49.81 ± 2.5 µg/ml, FC:139.42 ± µg/ml and FE:22.47 ± 0.5 µg/ul) along with positive control Doxorubicin 15.64 ± 0.8 µg/ml respectively by MTT assay. The molecular mechanism by which the four active compound induced apoptosis via reactive oxygen species (ROS) and cell cycle arrest in MCF-7 cells was determined H2DCFDA staining, DAPI staining, Acridine orange and ethidium bromide (AO/EtBr) dual staining, flowcytometry analysis with PI staining and apoptotic key regulatory proteins expression levels measured by westernblot analysis.

CONCLUSION

Our findings, revealed the anticancer potential of endophytic fungi from marine seaweed as a valuable source of bioactive compounds with anticancer properties and underscore the significance of exploring marine-derived endophytic fungi as a promising avenue for the development of novel anticancer agents. Further investigations are necessary to isolate and characterize specific bioactive compounds responsible for these effects and to validate their therapeutic potential in preclinical and clinical settings.

Fungal endophytes from saline-adapted shrubs induce salinity stress tolerance in tomato seedlings

To meet the food and feed demands of the growing population, global food production needs to double by 2050. Climate change-induced challenges to food crops, especially soil salinization, remain a major threat to food production. We hypothesize that endophytic fungi isolated from salt-adapted host plants can confer salinity stress tolerance to salt-sensitive crops. Therefore, we isolated fungal endophytes from shrubs along the shores of saline alkaline Lake Magadi and evaluated their ability to induce salinity stress tolerance in tomato seeds and seedlings. Of 60 endophytic fungal isolates, 95% and 5% were from Ascomycetes and Basidiomycetes phyla, respectively. The highest number of isolates (48.3%) were from the roots. Amylase, protease and cellulase were produced by 25, 30 and 27 isolates, respectively; and 32 isolates solubilized phosphate. Only eight isolates grew at 1.5 M NaCl. Four fungal endophytes (Cephalotrichum cylindricum, Fusarium equiseti, Fusarium falciforme and Aspergilus puniceus) were tested under greenhouse conditions for their ability to induce salinity tolerance in tomato seedlings. All four endophytes successfully colonized tomato seedlings and grew in 1.5 M NaCl. The germination of endophyte-inoculated seeds was enhanced by 23%, whereas seedlings showed increased chlorophyll and biomass content and decreased hydrogen peroxide content under salinity stress, compared with controls. The results suggest that the the four isolates can potentially be used to mitigate salinity stress in tomato plants in salt-affected soils.

Isolation, characterization, and multimodal evaluation of novel glycolipid biosurfactant derived from Bacillus species: A promising Staphylococcus aureus tyrosyl-tRNA synthetase inhibitor through molecular docking and MD simulations

Glycolipid-based biosurfactants (BSs), known for their intriguing and diverse properties, represent a largely uncharted territory in the realm of potential biomedical applications. This field holds great promise yet remains largely unexplored. This investigation provides new insights into the isolation, characterization, and comprehensive biomedical assessment of a novel glycolipid biosurfactant derived from Bacillus species, meeting the growing demand for understanding its multifaceted impact on various biomedical issues. Within this framework, two glycolipids, BG2A and BG2B, emerged as the most proficient strains in biosurfactant (BS) production. The biosurfactants (BSs) ascertained as glycolipids via thin layer chromatography (TLC) exhibited antimicrobial activity against S. aureus and E. coli. Both isolates exhibited anticancer effects against cervical carcinoma cells and demonstrated significant anti-biofilm activity against V. cholerae. Moreover, molecular docking and molecular dynamics (MD) simulations were employed to explore their antimicrobial resistance properties against Tyrosyl-tRNA synthetase (TyrRS) of Staphylococcus aureus, a well-annotated molecular target. Characterization and interpretation using Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy (1H and 13C NMR) confirmed that the BSs produced by each strain were glycolipids. These findings suggest that the isolated BSs can serve as effective agents with antibiofilm, antimicrobial, antioxidant, and anticancer properties, in addition to their considerable antibacterial resistance attributes.

Anti-multidrug-resistant Staphylococcus aureus and anti-dermatophyte activities of secondary metabolites of the endophytic fungus Penicillium brevicompactum ANT13 associated with the Algerian endemic plant Abies numidica

This study aims to identify and assess the antimicrobial activity of endophytic fungi found in the endemic plant Abies numidica. Among all isolates, the ANT13 isolate demonstrated significant antimicrobial activity in the preliminary screening, particularly Staphylococcus aureus ATCC 25923 and Candida albicans ATCC 1024, with inhibition zones of 22 and 21.5 mm, respectively. Based on its morphological and molecular features, this isolate was identified as Penicillium brevicompactum. The maximum activity was observed in the ethyl acetate extract, followed by the dichloromethane extract; however, the n-hexane extract exhibited no activity. The ethyl acetate extract demonstrated very significant activity against the five strains of multidrug-resistant Staphylococcus aureus used, with average zones of inhibition ranging from 21 to 26 mm, in contrast to more resistant Enterococcus faecalis ATCC 49452 and Bacillus cereus ATCC 10876. The ethyl acetate extract was also very active against dermatophytes, where the zones of inhibition for Candida albicans, Microsporum canis, Trichophyton mentagrophytes, Trichophyton rubrum, and Epidermophyton floccosum were 23.5, 31, 43, 47, and 53.5 mm, respectively. The MIC values for dermatophytes ranged between 100 and 3200 µg/mL. The wild isolate of Penicillium brevicompactum ANT13 discovered as an endophyte in Abies numidica may be a distinctive source of novel compounds and drug discovery to trait dermatophytes and multidrug-resistant Staphylococcus aureus infections.

Metabarcoding assessment of fungal diversity in brown algae and sponges of Mauritius

Marine fungi are largely associated with second most inhabitants of the marine ecosystem such as sponges and algae. They are important colonizers and play vital ecological roles, such as nutrient cycling, organic matter decomposition, and symbiosis with other organisms. High throughput sequencing methods have been used successfully to reveal unknown fungal communities associated with a number of hosts particularly in the marine environment. However, the diversity of marine fungi associated with sponges and brown algae in Mauritius remains largely unknown. Traditional methods based on culturing do not provide reliable estimate of fungal diversity as only those that are able to grow under laboratory conditions are dominant; in addition, a large proportion of fungi, cultured in vitro remain most of the time unidentifiable, given that there are no sporulating structures to be examined morphologically. To overcome these limitations, we employed Illumina sequencing to unravel fungi species present in the sponges, Iotrochota sp. and Biemna sp. and the brown algae Turbinaria conoides, Sargassum pfeifferae, and Sargassum obovatum, collected from the north of Mauritius. Diversity analyses revealed that Biemna sp. had the highest diversity from the sampled sponges with fungi from 24 orders being recovered while from brown algae; Turbinaria conoides had the highest diversity with recovery of fungal taxa of the orders Botryosphaeriales, Chaetothyriales, Eurotiales, Hypocreales, and Mucorales with the latter four orders being common in both sampled algae and sponges. Beta diversity analyses revealed clustering only in the algae, Turbinaria conoides, and Sargassum pfeifferae and not in the co-occurring sponges, indicating that sampling location did not have much influence on fungal diversity. Our findings provide the first amplicon sequencing based insights of the fungal communities associated with macro-algae and sponges in Mauritius and supplements research on the fungal community existing in the oceans around the world.

Fungal diversity notes 1512-1610: taxonomic and phylogenetic contributions on genera and species of fungal taxa

This article is the 14th in the Fungal Diversity Notes series, wherein we report 98 taxa distributed in two phyla, seven classes, 26 orders and 50 families which are described and illustrated. Taxa in this study were collected from Australia, Brazil, Burkina Faso, Chile, China, Cyprus, Egypt, France, French Guiana, India, Indonesia, Italy, Laos, Mexico, Russia, Sri Lanka, Thailand, and Vietnam. There are 59 new taxa, 39 new hosts and new geographical distributions with one new combination. The 59 new species comprise Angustimassarina kunmingense, Asterina lopi, Asterina brigadeirensis, Bartalinia bidenticola, Bartalinia caryotae, Buellia pruinocalcarea, Coltricia insularis, Colletotrichum flexuosum, Colletotrichum thasutense, Coniochaeta caraganae, Coniothyrium yuccicola, Dematipyriforma aquatic, Dematipyriforma globispora, Dematipyriforma nilotica, Distoseptispora bambusicola, Fulvifomes jawadhuvensis, Fulvifomes malaiyanurensis, Fulvifomes thiruvannamalaiensis, Fusarium purpurea, Gerronema atrovirens, Gerronema flavum, Gerronema keralense, Gerronema kuruvense, Grammothele taiwanensis, Hongkongmyces changchunensis, Hypoxylon inaequale, Kirschsteiniothelia acutisporum, Kirschsteiniothelia crustaceum, Kirschsteiniothelia extensum, Kirschsteiniothelia septemseptatum, Kirschsteiniothelia spatiosum, Lecanora immersocalcarea, Lepiota subthailandica, Lindgomyces guizhouensis, Marthe asmius pallidoaurantiacus, Marasmius tangerinus, Neovaginatispora mangiferae, Pararamichloridium aquisubtropicum, Pestalotiopsis piraubensis, Phacidium chinaum, Phaeoisaria goiasensis, Phaeoseptum thailandicum, Pleurothecium aquisubtropicum, Pseudocercospora vernoniae, Pyrenophora verruculosa, Rhachomyces cruralis, Rhachomyces hyperommae, Rhachomyces magrinii, Rhachomyces platyprosophi, Rhizomarasmius cunninghamietorum, Skeletocutis cangshanensis, Skeletocutis subchrysella, Sporisorium anadelphiae-leptocomae, Tetraploa dashaoensis, Tomentella exiguelata, Tomentella fuscoaraneosa, Tricholomopsis lechatii, Vaginatispora flavispora and Wetmoreana blastidiocalcarea. The new combination is Torula sundara. The 39 new records on hosts and geographical distribution comprise Apiospora guiyangensis, Aplosporella artocarpi, Ascochyta medicaginicola, Astrocystis bambusicola, Athelia rolfsii, Bambusicola bambusae, Bipolaris luttrellii, Botryosphaeria dothidea, Chlorophyllum squamulosum, Colletotrichum aeschynomenes, Colletotrichum pandanicola, Coprinopsis cinerea, Corylicola italica, Curvularia alcornii, Curvularia senegalensis, Diaporthe foeniculina, Diaporthe longicolla, Diaporthe phaseolorum, Diatrypella quercina, Fusarium brachygibbosum, Helicoma aquaticum, Lepiota metulispora, Lepiota pongduadensis, Lepiota subvenenata, Melanconiella meridionalis, Monotosporella erecta, Nodulosphaeria digitalis, Palmiascoma gregariascomum, Periconia byssoides, Periconia cortaderiae, Pleopunctum ellipsoideum, Psilocybe keralensis, Scedosporium apiospermum, Scedosporium dehoogii, Scedosporium marina, Spegazzinia deightonii, Torula fici, Wiesneriomyces laurinus and Xylaria venosula. All these taxa are supported by morphological and multigene phylogenetic analyses. This article allows the researchers to publish fungal collections which are important for future studies. An updated, accurate and timely report of fungus-host and fungus-geography is important. We also provide an updated list of fungal taxa published in the previous fungal diversity notes. In this list, erroneous taxa and synonyms are marked and corrected accordingly.

Metabolites Produced by Fungi against Fungal Phytopathogens: Review, Implementation and Perspectives

Many fungi, especially endophytes, have been found to produce multiple benefits in their plant hosts, with many of these benefits associated with the protection of plants against fungal diseases. This fact could be used in the development of new bio-products that could gradually reduce the need for chemical fungicides, which have been associated with multiple health and environmental problems. However, the utilization of the living organism may present several issues, such as an inconsistency in the results obtained and more complicated management and application, as fungal species are highly influenced by environmental conditions, the type of relationship with the plant host and interaction with other microorganisms. These issues could be addressed by using the bioactive compounds produced by the fungus, in cases where they were responsible for positive effects, instead of the living organism. Multiple bioactive compounds produced by fungal species, especially endophytes, with antifungal properties have been previously reported in the literature. However, despite the large amount of these metabolites and their potential, extensive in-field application on a large scale has not yet been implemented. In the present review, the main aspects explaining this limited implementation are analyzed, and the present and future perspectives for its development are discussed.