Different effects of microwave energy and conventional heat on the activity of a thermophilic ß-galactosidase from Bacillus acidocaldarius
✍ Scribed by Francesco La Cara; Maria Rosaria Scarffi; Sabato D'Auria; Rita Massa; Guglielmo d'Ambrosio; Giorgio Franceschetti; Mosè Rossi; Mario De Rosa
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 86 KB
- Volume
- 20
- Category
- Article
- ISSN
- 0197-8462
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✦ Synopsis
The effect of microwave (f ϭ 10.4 GHz) irradiation on a thermostable enzyme was experimentally tested, showing that irreversible inactivation is obtained. Enzymatic solutions (500 l, with concentrations between 10 -100 g/ml) were exposed at 70 ºC, at SAR levels of 1.1 and 1.7 W/g for 15, 30, 45, or 60 min, and their activity was compared to that of a sample heated in a water bath at the same temperature. The residual activity of the exposed samples depends on enzyme concentration, microwave power level, and exposure time; activity was reduced to 10% in 10 g/ml solutions treated at 1.7 W/g for 60 min. Microwave effects disappeared at concentrations above 50 g/ml. These results were not found following water bath heating at the same temperature and durations. Bioelectromagnetics 20:172-176, 1999.