Actinomadura sp. 101_SQ a moderate halotolerant isolated from salt lake in east of Algeria: A potential source of antibacterial substances
Year: 2026
Type: article
Abstract: Background: Microbial resistance is a critical global challenge to public health and sustainable development. This study aimed to assess the antibacterial activity of the 101_SQ strain, isolated from Ezzemoul salt lake (Algeria) against representative Gram-positive and Gram-negative bacteria, while profiling its secreted metabolites.Methods: The identified through polyphasic taxonomy. Antibiotic biosynthesis was screened using six distinct growth media. Bioactive compounds were characterized using HPLC and UV-Vis spectrophotometry, alongside an assessment of their thermal and photostability under varying conditions.The isolate was identified through polyphasic taxonomy. Antibiotic biosynthesis was screened using six distinct growth media. Bioactive compounds were characterized using HPLC and UV-Vis spectrophotometry, alongside an assessment of their thermal and photostability under varying conditions.Results: Plypahsic analysis (phenotypic, chemotaxonomic, and 16S rDNA) revealed that isolate 101_SQ was closely affiliated with Actinomadura geliboluensis A8036 (99%), A. meyerae A288, A. bangladeshensis 3-46-b and A. chokoriensis 3-45-a(11) (99% similarity). Bennett’s medium was most suitable for stimulating antibiotic synthesis. Isoamyl acetate and hexane exhibited the highest efficiency, particularly against Staphylococcus aureus Mu 50. UV-Vis analysis indicated the likely non-polyenic nature of the metabolites, as characteristic polyene absorption bands were absent. HPLC profiling revealed three distinct peaks, suggesting the presence of multiple bioactive constituents. The antibacterial activity was thermolabile (declining at 50-100°C) but remained stable under freezing and varying light conditions.Conclusion: Strain 101_SQ produces non-polyene antibacterials, thermolabile but stable to freezing and light, suggesting pharmaceutical and biotechnological potential.
Authors: Lamia Oulmi, Mahmoud Kitouni
Institution: University Frères Mentouri Constantine 1
Language: English
Subfield: Applied Microbiology and Biotechnology
Field: Immunology and Microbiology
Domain: Life Sciences
Open Access status: diamond
OpenAlex ID: W7166360322