INVESTIGADORES
RUIZ Diego Mario
congresos y reuniones científicas
Título:
Activity and Stability of the Extracellular Protease from the haloalkaliphilic archaeon Natrialba magdii in organic media.
Autor/es:
RUIZ DM; DE CASTRO RE
Lugar:
Pinamar (Buenos Aires)
Reunión:
Congreso; 41 th. Annual Meeting - Argentine Society for Biochemistry and Molecular Biology Research (SAIB).; 2005
Institución organizadora:
Sociedad Argentina de Investigacion en Bioquimica y Biologia Molecular (SAIB)
Resumen:
The haloalkaliphilic archaeon Nab. magadii produces an extracellular protease at the end of exponential growth phase denoted as NEP for Natrialba magadii Extracellular Protease. This enzyme has the maximum activity for azocasein hydrolysis at 1.5 M NaCl and pH 8 at 45ºC. As salt has the effect of reducing water activity, this protease might be stable and active in aqueous/organic solvent and/or organic solvent media. The aim of this study was to analyze the activity and stability of NEP in the presence of different organic solvents. The azocaseinolytic activity was measured in solutions with decreasing salt concentrations (1.5 – 0.15 M NaCl) in the presence or absence of 30% (v/v) dimethylsulfoxide (DMSO) or dimethylformamide (DMF). The enzyme was partially purified from culture media harvested in the stationary phase (OD600>1.5). In the presence of DMSO the proteolytic activity was at least 2–fold higher than the control (without DMSO) for salt concentrations lower than 1.5 M NaCl. However, DMF had a negative effect on the hydrolytic NEP activity. The stability of NEP was greatly enhanced by addition of DMSO even at salt concentrations as low as 0.15 M NaCl. These results show that NEP is a potential tool for biotechnological processes that involve biocatalysis in organic media. Supported by grants from UNMDP and CONICET.