Evaluation of antifungal activity of novel marine actinomycete, Streptomyces sp. AA13 isolated from sediments of Lake Oubeira (Algeria) against Candida albicans

Abstract

A new actinomycete strain, designated AA13 was isolated from a marine sediment sample obtained from Lake Oubeira, in the NorthEast of Algeria and selected for its antifungal activities against Candida albicans. Morphological, physiological and biochemical properties and 16S rRNA gene sequencing strongly suggested that this strain was a new species, which belonged to the genus Streptomyces. Study of the influence of different nutritional compounds and culture conditions on growth and production of compounds with antifungal activity by the Streptomyces sp. strain AA13 indicated that the highest biomass and biological activities were obtained by utilizing the glycerol and peptone as carbon and nitrogen sources, respectively, with pH 7.0 and incubation temperature of 30°C. Two bioactive spots were detected by analysis of the ethyl acetate extract by thin-layer chromatography (TLC) and bioautography analyses. Among these bioactive compounds (antibiotics), a complex AA13-B that showed the interesting antifungal activity, was selected and purified by high performance liquid chromatography (HPLC), which indicated the presence of three peaks. Interestingly, the infrared spectroscopy (IR) studies showed that the molecule AA13-B2 contain an aromatic ring substituted by aliphatic chains. However, the investigations which determine the structure of the antifungal molecule are in progress.

Antibiotic-Producing Streptomyces sp. Isolated from the Soil of a Mangrove Ecosystem

“…Streptomyces sp. isolates found in the sediments of Lake Oubeira, Algeria, were found to have an inhibitory effect against Candida albicans (Adel et al 2016, Ryandini et al 2021.…”

Streptomyces species from the rhizosphere of the medicinal plant Artemisia herba-alba Asso: screening for biological activities

“…AA13 that showed potential antimicrobial, antifungal properties and activity against Candida albicans, 11 respectively (Morakchi et al 2009;Ayari et al 2011;Ayari et al 2016). The filtrate of the endophytic strain Streptomyces sp.…”

Identification and Antibacterial Activity of Streptomyces mediolani CF51DZ Isolated from the Beetle (Protaetia morio), Collected from Souk Ahras, North-East of Algeria

“…1 ml of methanol was used to dissolve the crude residue for further use. 6,16 The obtained compound was used to determine the antibacterial activity via the agar well diffusion method as previously described. 24 hours after the 37°C incubation period, the Petri dishes were inspected for the inhibition zones.…”

“…4,5 Actinomycetes are one of the most diverse bacterial groups in nature, able to generate bioactive molecules. 6,7 Discovery of new secondary metabolites as bioactive molecules in unexplored habitats is pointed out as strategic actions to fight against the growing number of microorganisms that are resistant to a wide range of antibiotics obtained from actinomycetes. 8 Many actinobacteria, including Streptomycetes have been isolated as appropriate defensive partners associated withvarious types of insects, 9 and in this regard, Streptomyces and Pseudonocardia were reported to protect the leaf-cuttingants against pathogenic fungus.…”