Characterization and valorization of thermophilic exopolysaccharides as natural carriers for antibiotic encapsulation from Algerian strains: Brevibacillus borstelensis Gp-1 and Bacillus licheniformis  AS28

Fatima Zohra, Abdi; Abdelmalek, Ilham; Tir Touil, Aicha; Bouteldja, Rachida; Aggad, Habib; Doucene, Radhouane; Benhammouda, Liela Soher

doi:10.21608/mb.2025.387129.1329

Characterization and valorization of thermophilic exopolysaccharides as natural carriers for antibiotic encapsulation from Algerian strains: Brevibacillus borstelensis Gp-1 and Bacillus licheniformis AS28

Document Type : Original Article

Authors

¹ Laboratory of Bioconversion, Microbiological Engineering and Health Safety, Faculty of Nature and Life Sciences, University Mustapha Stambouli, Oran Street, Mascara 29000, Algeria.

² Synthetic and Catalyst Laboratory, Faculty of Matter Sciences, University of Ibn Khaldoun, Tiaret 14000, Algeria.

³ Laboratory of Hygiene and Animal Pathology, Veterinary Sciences Institute, University of Ibn Khaldoun, ITMA Tiaret 14000, Algeria.

⁴ Laboratory Reproduction of Farm Animals, Institute of Veterinary Sciences, University of Ibn Khaldoun, Tiaret 14000, Algeria.

10.21608/mb.2025.387129.1329

Abstract

Exopolysaccharides (EPS) produced by thermophilic bacteria offer promising potential as bioactive compounds in medical and pharmaceutical applications. This study focuses on the extraction and characterization of EPS from Brevibacillus borstelensis strain Gp-1 and Bacillus licheniformis strain AS28, with a comparative analysis of their structural and functional properties. The findings reveal that B. licheniformis displayed a higher EPS yield than B. borstelensis, indicating potential metabolic and significant environmental adaptations. Molecular mass analysis identified low-molecular-weight EPS (<5 kDa), which were associated with enhanced bioactivity. Structural characterization using FTIR and DRX confirmed that the EPS are predominantly curdlan-type β-(1,3)-glucans with prominent thermal stability. Furthermore, the encapsulation of antibiotics using these EPS demonstrated significant synergistic effects against both sensitive and resistant bacterial strains (E. coli and Staphylococcus aureus), suggesting potential applications in controlled-release drug formulations. The exceptional structural and functional properties of these thermophilic bacterial EPS position them as viable candidates for drug delivery systems and regenerative medicine. Further investigation into their biocompatibility and therapeutic efficacy could unveil innovative strategies for combating antibiotic resistance and advancing targeted drug delivery approaches.

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