Exploring the antimicrobial potential of two haloarchaeal strains belonging to the genera Halopiger and Natrialba isolated from the Algerian Sahara

Inès Quadri; Imene Ikram Hassani; Hocine Hacène

doi:10.18502/ijm.v17i1.17812

Inès Quadri Department of Cellular and Molecular Biology, Cellular and Molecular Biology Laboratory (Team Microbiology), University of Sciences and Technology Houari Boumediene, Bab Ezzouar, Algiers, Algeria
Imene Ikram Hassani Department of Cellular and Molecular Biology, Cellular and Molecular Biology Laboratory (Team Microbiology), University of Sciences and Technology Houari Boumediene, Bab Ezzouar, Algiers, Algeria
Hocine Hacène Department of Cellular and Molecular Biology, Cellular and Molecular Biology Laboratory (Team Microbiology), University of Sciences and Technology Houari Boumediene, Bab Ezzouar, Algiers, Algeria

DOI: https://doi.org/10.18502/ijm.v17i1.17812

Keywords: Archaea; Halopiger; Natrialba; Extreme environments; Antimicrobial peptides; Peripheral blood mononuclear cells

Abstract

Background and Objectives: Halophilic archaea commonly produce antimicrobial peptides (halocins), but only a few studies have been conducted on these molecules. This study explores the antimicrobial potential of two strains belonging to Halopiger and Natrialba genera, isolated from hypersaline environments in the Algerian Sahara. Antimicrobial compounds produced by these genera have rarely been studied before.

Materials and Methods: The antimicrobial activity of the strains was evaluated, along with the effects of UV radiation and culture conditions on growth and compound production. Stability assays and the effects of extracted compounds on target cells and peripheral blood mononuclear cells (PBMC) were assessed.

Results: The strains exhibited high anti-archaeal activities and cross-domain interactions. Producing extracellular com- pounds associated with halocin, in the cell-free supernatant (CFS). These compounds remained stable at different tempera- tures (4°C, 60°C, 80°C, and 100°C) and different pH ranges (4-10 and 5-11), with antimicrobial profiles changed in response to UV light. The active compounds resembled known halocins but displayed unique features suggesting the discovery of new halocins. Additionally, Natrialba extracts showed significant activity against PBMC.

Conclusion: This investigation confirms that Algerian saline soils are a promising source of interesting antimicrobial com- pounds.