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Published on: August 10, 2016
Thermal stability and catalytic properties of protease from Bacillus sp. P45 active in organic solvents and ionic
Thais M de Borba1, Taiele B Machado1, Adriano Brandelli2
1Laboratório de Microbiologia e Biosseparações, Escola de Química de Alimentos, Universidade Federal do Rio Grande, Rio Grande, RS , 96203-900, Brazil.
Abstract:
The parameters half-life, z value, enthalpy, entropy, and free energy were evaluated in the temperature range of 40 to 55°C for a Bacillus sp. P45 protease present in a medium composed of ionic liquid (IL) and organic solvent. The protease was previously treated in IL [Emim][Tf2 N] and increased activity was observed in four out of five organic solvents tested. The reaction medium containing acetone and IL (1:1 v/v ratio) was more stable than the buffer medium, with half-life of 2.4 h at 55°C. Thermodynamic parameters values showed there was probably less rupture of non-covalent bonds that stabilize the protein structure, which promoted the protease P45 stabilization. According to this study it was concluded that the protease P45 in a medium composed of [Emim][Tf2 N] and acetone may be used at higher temperatures than those employed in buffer or medium containing organic solvent. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 2018 © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:1102-1108, 2018.
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