Physiological and antioxidant response by Beauveria bassiana Bals (Vuill.) to different oxygen concentrations.
The effect of three levels of oxygen (normal atmosphere (21% O(2)), low oxygen (16% O(2)) and enriched oxygen (26% O(2))) on the production and germination of conidia by Beauveria bassiana was evaluated using rice as a substrate. The maximum yield of conidia was achieved under hypoxia (16% O(2)) after 8 days of culture (1.51 × 10(9) conidia per gram of initial dry substrate), representing an increase of 32% compared to the normal atmosphere. However, germination was reduced by at least 27% due to atmospheric modifications. Comparison of antioxidant enzyme activity (superoxide dismutases and catalases) with the oxidation profiles of biomolecules (proteins and lipids) showed that a decrease in catalase activity in the final days of culture coincided with an increase in the amount of oxidized lipids, showing that oxidative stress was a consequence of pulses of different concentrations of O(2). This is the first study describing oxidative stress induction by atmospheric modification, with practical implications for conidia production.
Departamento de Biotecnología, Universidad Autónoma Metropolitana-Iztapalapa, 09340, México, DF, Mexico.
Paul Misael
PM
Garza-López
Mina
M
Konigsberg
Luis Enrique
LE
Gómez-Quiroz
Octavio
O
Loera
D000975:Antioxidants / Q000378:metabolism; D052982:Beauveria / Q000254:growth & development / Q000502:physiology*; D002374:Catalase / Q000378:metabolism; D005656:Fungal Proteins / Q000378:metabolism; D015227:Lipid Peroxidation; D018384:Oxidative Stress; D010100:Oxygen / Q000378:metabolism; D013172:Spores, Fungal / Q000254:growth & development / Q000502:physiology; D013482:Superoxide Dismutase / Q000378:metabolism
D000975:Antioxidants; D005656:Fungal Proteins; D002374:Catalase; D013482:Superoxide Dismutase; D010100:Oxygen