INVESTIGADORES
BRECCIA Javier Dario
artículos
Título:
Thermal stabilization by polyols of ß-xylanase from Bacillus amyloliquefaciens. Journal Chemical Technology Biotechnology
Autor/es:
BRECCIA JD,; MORÁN AC,; CASTRO GR,; SIÑERIZ F,
Revista:
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
Editorial:
Wiley
Referencias:
Año: 1998 vol. 17 p. 241 - 245
ISSN:
0268-2575
Resumen:
Purified endo--1,4-xylanase of Bacillus amyloliquefaciens MIR 32 retained 100% of its activity after 4 days of incubation at 50°C. Sorbitol (400 mg cm-3) produced a 63-fold increase in the half-life of the enzyme at 65°C, which was only 29 min at this temperature in the absence of the polyol. This thermal stabilizing activity increased exponentially in respect to sorbitol concentration in the range 250-400 mg cm-3 and was dependent on the pH, showing a maximum at pH values between 5·25 and 8·0. The circular dichroism (CD) thermal scanning profile (50°C h-1) at 224 nm showed that changes in the secondary structure of xylanase started at 65°C, while in the presence of sorbitol (400 mg cm-3) these modifications started at 80°C. This study indicated that sorbitol might be a valuable stabilizer for the use of -xylanase from B. amyloliquefaciens at high temperatures.