Catalytic and thermodynamic properties of [beta]-glucosidases produced by Lichtheimia corymbifera and Byssochlamys spectabilis

• Published in: Preparative biochemistry & biotechnology 2018-01, Vol.48 (9), p.777
• Main Authors: Morais, Tobias Pereira de, Barbosa, Paula Mirella Gomes, Garcia, Nayara Fernanda Lisboa, Rosa-Garzon, Nathália Gonsales da, Fonseca, Gustavo Graciano, Paz, Marcelo Fossa da, Cabral, Hamilton, Leite, Rodrigo Simões Ribeiro
• Format: Article
• Language: English
• Subjects: Byssochlamys spectabilis; Catalysis; Cultivation; Denaturation; Enzymes; Ethanol; Fermentation; Glucosidase; Lichtheimia corymbifera; Optimization; Parameters; pH effects; Saccharification; Substrates; Thermal stability; Thermodynamic properties; Thermophilic fungi
• ISSN: 1082-6068; 1532-2297
• DOI: 10.1080/10826068.2018.1509083

The objective of the present study was to optimize parameters for the cultivation of Lichtheimia corymbifera (mesophilic) and Byssochlamys spectabilis (thermophilic) for the production of [beta]-glucosidases and to compare the catalytic and thermodynamic properties of the partially purified enzymes. The maximum amount of [beta]-glucosidase produced by L. corymbifera was 39 U/g dry substrate (or 3.9 U/mL), and that by B. spectabilis was 77 U/g (or 7.7 U/mL). The optimum pH and temperature were 4.5 and 55 °C and 4.0 and 50 °C for the enzyme from L. corymbifera and B. spectabilis, respectively. [beta]-Glucosidase produced by L. corymbifera was stable at pH 4.0-7.5, whereas the enzyme from B. spectabilis was stable at pH 4.0-6.0. Regarding the thermostability, [beta]-glucosidase produced by B. spectabilis remained stable for 1 h at 50 °C, and that from L. corymbifera was active for 1 h at 45 °C. Determination of thermodynamic parameters confirmed the greater thermostability of the enzyme produced by the thermophilic fungus B. spectabilis, which showed higher values of [Delta]H, activation energy for denaturation (Ea), and half-life t(1/2). The enzymes were stable in the presence of ethanol and were competitively inhibited by glucose. These characteristics contribute to their use in the simultaneous saccharification and fermentation of vegetable biomass.