Bacterioruberin extracts from a genetically modified hyperpigmented Haloferax volcanii strain: antioxidant activity and bioactive properties on sperm cells

• Published in: Journal of applied microbiology 2019-03, Vol.126 (3), p.796-810
• Main Authors: Zalazar, L., Pagola, P., Miró, M.V., Churio, M.S., Cerletti, M., Martínez, C., Iniesta‐Cuerda, M., Soler, A.J., Cesari, A., De Castro, R.
• Format: Article
• Language: English
• Subjects: Animals; Antioxidants; Antioxidants - metabolism; Antioxidants - pharmacology; bacterioruberin; Biological activity; Biotechnology; Carotene; Carotenoids; Carotenoids - metabolism; Carotenoids - pharmacology; Cryopreservation; Electron paramagnetic resonance; Freezing; Genetic; Genetic modification; Haloferax volcanii; Haloferax volcanii - chemistry; Haloferax volcanii - genetics; Haloferax volcanii - metabolism; Male; Microorganisms; Parameters; ram sperm cells; Sheep; Sperm; Sperm Motility - drug effects; Spermatozoa - cytology; Spermatozoa - drug effects; Thawing; Velocity; β-Carotene
• ISSN: 1364-5072; 1365-2672
• DOI: 10.1111/jam.14160

Aims To examine the antioxidant activity of Bacterioruberin (Bctr)‐rich extracts isolated from a hyperpigmented, genetically modified Haloferax volcanii strain (HVLON3) and to investigate the effect on cold‐sensitive ram sperm cells. Methods and Results The strain HVLON3 produces higher Bctr amounts than most haloarchaea (220 ± 13 mg g−1 DW). HVLON3‐Bctr extract has higher antioxidant activity than β‐carotene (threefold) as evaluated using 2,2 diphenyl‐1‐picrylhydrazyl combined with Electron Paramagnetic Resonance analysis (EC50 4·5 × 10−5 mol l−1 vs 13·9 × 10−5 mol l−1 respectively). Different concentrations of HVLON3‐Bctr extracts were assayed on ram sperm after freezing/thawing and physiologically relevant parameters were examined. Extracts containing 7 and 20 μmol l−1 Bctr significantly improved cell viability (P