Characterization of biocatalysts prepared with Thermomyces lanuginosus lipase and different silica precursors, dried using aerogel and xerogel techniques.
The use of lipases in industrial processes can result in products with high levels of purity and at the same time reduce pollutant generation and improve both selectivity and yields. In this work, lipase from Thermomyces lanuginosus was immobilized using two different techniques. The first involves the hydrolysis/polycondensation of a silica precursor (tetramethoxysilane (TMOS)) at neutral pH and ambient temperature, and the second one uses tetraethoxysilane (TEOS) as the silica precursor, involving the hydrolysis and polycondensation of the alkoxide in appropriate solvents. After immobilization, the enzymatic preparations were dried using the aerogel and xerogel techniques and then characterized in terms of their hydrolytic activities using a titrimetric method with olive oil and by the formation of 2-phenylethyl acetate in a transesterification reaction. The morphological properties of the materials were characterized using scanning electron microscopy, measurements of the surface area and pore size and volume, thermogravimetric analysis, and exploratory differential calorimetry. The results of the work indicate that the use of different silica precursors (TEOS or TMOS) and different drying techniques (aerogel or xerogel) can significantly affect the properties of the resulting biocatalyst. Drying with supercritical CO2 provided higher enzymatic activities and pore sizes and was therefore preferable to drying, using the xerogel technique. Thermogravimetric analysis and differential scanning calorimetry analyses revealed differences in behavior between the two biocatalyst preparations due to the compounds present.
Carlos Eduardo
CE
Barão
Leandro
L
Daniel de Paris
João Henrique
JH
Dantas
Matheus Mendonça
MM
Pereira
Lucio Cardozo
LC
Filho
Heizir
H
Ferreira de Castro
Gisella Maria
GM
Zanin
Flavio
F
Faria de Moraes
Cleide Mara
CM
Faria Soares
D001203:Ascomycota / Q000201:enzymology*; D055162:Biocatalysis; D003890:Desiccation; D004800:Enzymes, Immobilized; D004951:Esterification; D005782:Gels; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008049:Lipase / Q000737:chemistry* / Q000378:metabolism*; D012821:Silanes / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D013696:Temperature
D004800:Enzymes, Immobilized; D005782:Gels; D012821:Silanes; D012997:Solvents; C061205:tetramethoxysilane; D012822:Silicon Dioxide; D008049:Lipase