Antimicrobial activities of culturable microorganisms (actinomycetes and fungi) isolated from Chaabe Cave, Algeria
Year: 2018
Type: article
Abstract: The discovery of new antibiotics and other bioactive microbial metabolites is a priority given the frequency of the emerging multi-drug resistant pathogenic microorganisms. Thus, scientists are searching for new antibiotics in microorganisms isolated from extreme habitats such as caves. In the present study, we aimed to perform the first analysis on culturable microorganisms in the Chaabe Cave (Algeria), and to test the antimicrobial activities of the isolates (Streptomyces spp. and Penicillium spp.). The potential for antimicrobial activity of 47 strains of actinomycetes and 23 strains of fungi were tested on Candida albicans, Staphylococcus aureus, Micrococcus luteus, Listeria monocytogenes, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa. The identification of the most active actinomycetes strains by 16S rRNA gene sequence analysis revealed that these isolates were exclusively affiliated to the genus Streptomyces. On the other hand, the fungi were determined by phylogenetic analysis based on the ITS region or on the β tubulin gene and were affiliated to the genera Readeriella, Cladosporium, Aspergillus, Penicillium, Beauveria, Alternaria, Rhizopus, and Rhizomucor. The strains showed strong inhibitory activity against pathogenic microorganisms and the diameters of the inhibition zones vary between 7.5 and 34 mm for Streptomyces strains, and between 6.5 and 19.50 mm for Penicillium strains. The data indicated that the majority (72.86%) of the 70 isolates were active against at least one of the tested microorganisms. The production of nonpolyenic antifungal substances by active Streptomyces isolates was investigated using several criteria (antibacterial activity, ergosterol inhibition, and UV-visible spectra) of active extracts. The results were promising and showed that the metabolites produced by the actinomycete strains do not have a UV-visible spectrum characteristic of a polyenic structure. The Chaabe Cave possesses a diversity of microorganisms that could lead to new antibiotics necessary in the fight against drug-resistant pathogens and warrant further study.
Authors: Université Abou Bekr Belkaid, Larbi Belyagoubi, Nabila Belyagoubi-Benhammou, Université Abou Bekr Belkaid, Valme Jurado, Instituto de Recursos Naturales y Agrobiologias, Joëlle Dupont, Institut de Systématique, Évolution et Biodiversité, Sandrine Lacoste, Institut de Systématique, Évolution et Biodiversité, Fatima Djebbah, Université Abou Bekr Belkaid, Fatima Ounadjela, Université Abou Bekr Belkaid, Souad Benaissa, Université Abou Bekr Belkaid, Salim Habi, Université Abou Bekr Belkaide, Djamel Abdelouahid, Université Abou Bekr Belkaid, Cesareo Saiz-Jimenez, Instituto de Recursos Naturales y Agrobiologia
Institutions: University of Abou Bekr Belkaïd, Consejo Superior de Investigaciones Científicas, Instituto de Recursos Naturales y Agrobiología de Sevilla, Centre National de la Recherche Scientifique, École Pratique des Hautes Études, Sorbonne Université, Institut de Systématique, Évolution, Biodiversité, Muséum national d'Histoire naturelle, Université Pierre-et-Marie-Curie
Language: English
Subfield: Applied Microbiology and Biotechnology
Field: Immunology and Microbiology
Domain: Life Sciences
Open Access status: diamond
OpenAlex ID: W2808209575