Antimicrobial properties of marine fungi from sponges and brown algae of Mauritius

Abstract

Purpose of the study: Marine fungi of Mauritius have been poorly studied. There are numerous reports on the bioactive secondary metabolites that are produced by fungi around the world. Yet, research on the molecular characterisation and the pharmaceutical potential of marine fungi in Mauritius is rather scanty. Method: The samples, which consisted of three sponges Haliclona sp., Iotrochota sp. and Biemna sp. and two brown algae Turbinaria conoides and Sargassum portierianum, were collected in the North of Mauritius during winter. No sporulating structures were observed from the fungal cultures making morphological analysis impossible. The molecular characterisation of the selected isolates was carried out by the amplification of the ITS regions and phylogenetic analysis. The antimicrobial properties were then determined using the disc diffusion and the minimum inhibitory concentration (MIC) assay. Results: Genus level identification was made from molecular data and for some isolates, specieslevel identification was even possible. Twelve fungi that showed the best antimicrobial properties were identified as Peniophora sp., Aspergillus cristatus, Acremonium sp., Cordyceps memorabilis, Aspergillus ochraceus, Biscogniauxia sp., Aspergillus keratitidis, Exserohilum rostratum, Chromocleista sp., Nigrospora oryzae, Aspergillus flavipes and Mycosphaerella. The lowest MIC result of 0.0098 mg/ mL was obtained with Chromocleista sp. mycelium extract against Staphylococcus aureus. The MIC of the mycelium extracts was lower than the broth extracts for most isolates indicating that the antimicrobial compounds are not secreted. Conclusion:Marine fungi from the Mauritian waters have immense potential in the search for natural products against antibiotic-resistant bacteria.

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

“…The culture-independent method used in this study showed higher fungal diversity compared to a previous traditional microbiological study from our research group that involved the same sponge and algal species ( Wong Chin et al, 2021 ). The marine ecosystem provides abundant opportunities to discover novel fungi that can advance our understanding of fungal diversity and ecology while expanding the current repertoire of organisms from the Mauritius waters with the potential to contribute to drug discovery.…”

Marine fungi showing multifunctional activity against human pathogenic microbes and cancer

“…Previously, bioactive polyketides were identified from Phomopsis sp. isolated from both marine and terrestrial habitats [ 13 , 59 , 60 ]. Microdochium sp.…”

Multigene phylogeny, bioactive properties, enzymatic and dye decolorization potential of selected marine fungi from brown algae and sponges of Mauritius

“…Five fungi, which were obtained from the previous work of Wong Chin et al [ 34 ] were selected for multigene phylogenetic analyses. In the previous work, these isolates were identified based on ITS rDNA sequences and phylogenetic analyses.…”

“…They were Aspergillus cristatus (F2), Aspergillus ochraceus (F25), Exserohilum rostratum (F33), Chromocleista sp. (F34) and Aspergillus flavipes (F37) [ 34 ].…”