No abstract

A busca por suportes alternativos para imobilização tem motivado diversos estudos na área de enzimologia, deste modo, o uso de sabugo de milho como suporte orgânico, pode ser uma alternativa. Portanto, neste trabalho se verificou a utilização de sabugo de milho como suporte para a imobilização de lipase. A granulometria média do sabugo de milho utilizada foi de 32-60 mesh, e apresentou 27% celulose, 24% hemicelulose e 36% de lignina. Testes de biodegradabilidade do suporte foram realizados, e o suporte não apresentou nenhuma formação de compostos de degradação. A lipase imobilizada apresentou um rendimento de imobilização de 62% e boa estabilidade operacional, mantendo entre 55 a 60% da sua atividade inicial até o sexto ciclo. O pH e temperatura ótimos para os biocatalisadores imobilizados foram 7,0 e 55ºC. Os parâmetros cinéticos para o modelo de Michaelis-Mentem (Km e Vmax) foram 616,95 U/g e 361,38, respectivamente. Palavras-chave:Resíduos agroindustriais, materiais lignocelulósicos, sabugo de milho, imobilização, lipase.

Ionic liquids can act as support modifiers and additives in the enzymatic immobilization process, providing more efficient and stable immobilized biocatalysts. In this context, the present work aims to evaluate the influence of aprotic ionic liquids (AIL), ethyl (C2), butyl (C4) e hexyl (C6) of 3-methylimidazolium bis (trifluoromethysulphonyl) imid) in the preparation of hybrid support formed by hydroxybutyrate-hydroxyvalerate (PHBV) and silica for posterior immobilization of Burkholderia cepacia lipase (BCL). Biochemical characterization was evaluted pH (4 -8), temperature (37 -75 °C), thermal stability (55 and 65 °C) and operational stability. Immobilized biocatalysts (IB) higher values immobilization yield obtained IB-C4 (171 ± 1%) and IB-C6 (169 ± 3%) higher than the IB-Control (90%). It can be observed that the free and immobilized BCL by covalent binding presented a better hydrolytic activity at neutral pH (7.0) and the temperature of 50 °C, indicating that the modification of the hybrid support with AIL did not interfere in the pH and optimum temperature of the enzyme. In the study of thermal stability, the AIL modified biocatalysts of higher alkyl chains (C4 and C6) were more stable than the control in the higher ranges of the temperatures studied (55 and 65 °C). The reuse of BCL showed similar results for the biocatalysts IB-C4 and IB-C6, which were reused 11 times, maintaining 50% of the initial activity, whereas the control presented only six reuses. Therefore, the use of modified supports with aprotic ionic liquids for enzyme immobilization offers new perspectives for the industry, thus increasing its efficiency, stability and reuse.

Biochar, a product of the pyrolysis of agroindustrial wastes, is recognized as a multifunctional material. Its use as a support in enzyme immobilization has been successfully reported in order to reduce immobilization processes costs and to promote stabilization of enzymes. The objective of this work was to elucidate the adsorption process of lipase from Burkholderia cepacia (BCL) on biochar from guava seeds by fitting the experimental data to four typical isotherm models such as Langmuir, Sips, Freundlich and Redlich-Peterson. According to results, Sips isotherm model had a better fit to the experimental data, considering its highest correlation coefficient (R 2 = 0.9879) and the lowest ARE value (0.0103).