RESUMO
Lignocellulosic biomasses are used in several applications, such as energy production, materials, and biofuels. These applications result in increased consumption and waste generation of these materials. However, alternative uses are being developed to solve the problem of waste generated in the industry. Thus, research is carried out to ensure the use of these biomasses as enzymatic support. These surveys can be accompanied using the advanced bibliometric analysis tool that can help determine the biomasses used and other perspectives on the subject. With this, the present work aims to carry out an advanced bibliometric analysis approaching the main studies related to the use of lignocellulosic biomass as an enzymatic support. This study will be carried out by highlighting the main countries/regions that carry out productions, research areas that involve the theme, and future trends in these areas. It was observed that there is a cooperation between China, USA, and India, where China holds 28.07% of publications in this area, being the country with the greatest impact in the area. Finally, it is possible to define that the use of these new supports is a trend in the field of biotechnology.
RESUMO
Enzymatic biocatalysis is a sustainable technology. Enzymes are versatile and highly efficient biocatalysts, and have been widely employed due to their biodegradable nature. However, because the three-dimensional structure of these enzymes is predominantly maintained by weaker non-covalent interactions, external conditions, such as temperature and pH variations, as well as the presence of chemical compounds, can modify or even neutralize their biological activity. The enablement of this category of processes is the result of the several advances in the areas of molecular biology and biotechnology achieved over the past two decades. In this scenario, metal-organic frameworks (MOFs) are highlighted as efficient supports for enzyme immobilization. They can be used to 'house' a specific enzyme, providing it with protection from environmental influences. This review discusses MOFs as structures; emphasizes their synthesis strategies, properties, and applications; explores the existing methods of using immobilization processes of various enzymes; and lists their possible chemical modifications and combinations with other compounds to formulate the ideal supports for a given application.
Assuntos
Estruturas Metalorgânicas , Biocatálise , Biotecnologia , Enzimas Imobilizadas/química , Estruturas Metalorgânicas/química , TemperaturaRESUMO
ß-glucosidase from almonds was immobilized on a polydimethylsiloxane (PDMS) microdevice by covalent chain using 3-aminopropyltrietoxysilane and glutaraldehyde. Enzymatic activity was evaluated using p-nitro-phenyl-ß-D-glucopyranoside dissolved in a 0.01â¯M pH 5.0 phosphate solution at 45⯰C measuring the reaction product (p-nitrophenol) at 410â¯nm. The microdevice consisted of two parts: the one part where the enzymatic reaction was carried out and a second part where pH was adjusted at 10, with NaOH. The reaction product was measured at the microchip exit using two optical fibers which were aligned facing each other with a gap of 7â¯mm, between both tips using guides located perpendicular to the flow outlet. A water bath was used to carry out the enzymatic reaction on the microdevice at 45⯰C. The enzymatic surface of the PDMS microdevice was 1.15â¯cm2 and the immobilized ß-glucosidase amount on the microdevice was of 1.17⯵g/cm2. The calculated kinetics parameters were: Km 2.5â¯mM; Vmax 2.2â¯mM/min; Kcat 908.3/min and Kcat/Km 363.3/mM min. The immobilized enzyme is very stable decreasing only 5% the first 15 days; on the 30th day, the activity was 69%, regarding the initial activity.
Assuntos
Dimetilpolisiloxanos/metabolismo , Enzimas Imobilizadas/metabolismo , Análise de Injeção de Fluxo , Técnicas Analíticas Microfluídicas , Fibras Ópticas , beta-Glucosidase/metabolismo , Dimetilpolisiloxanos/químicaRESUMO
Tendo como objetivo a redução de custos do processo de fabricação de hidrolisados protéicos, estudou-se neste trabalho a imobilização da pancreatina, por adsorção, em carvão ativado e em alumina. Para isso, foram testadas diferentes condições de imobilização (30, 60 e 90min a 25°C, e 12h a 5°C). Para verificar a taxa de imobilização, determinou-se indiretamente a enzima não adsorvida nos suportes. Ao se utilizar o carvão ativado, não foi observada diferença significativa entre as condições testadas, tendo-se obtido 100% de imobilização enzimática. Para a alumina, a melhor condição foi a de 90min, na qual se obteve 37% de imobilização. A medida do grau de exposição da fenilalanina, pela espectrofotometria derivada segunda, foi empregada para a determinação da estabilidade operacional da enzima, tendo sido mostrado que a imobilização em carvão ativado e em alumina permitiu a reutilização da pancreatina por até 5 vezes e 2 vezes, respectivamente.
Immobilization of pancreatin in activated carbon and in alumina was studied for producing protein hydrolysates, in order to reduce the process costs. Different immobilization conditions were tested (30, 60 and 90min at 25°C, and 12h at 5°C). For estimating the immobilization rate the amount of the non-adsorbed enzyme on the supports was indirectly determined. When activated carbon was used, no significant difference was observed among the tested conditions, obtaining 100% of enzymatic immobilization. In case of alumina, the best condition showed to be the 90min treatment which produced 37% of immobilization. The evaluation of the degree of exposition of phenylalanine, by second derivative spectrophotometry, was used for the determination of the enzyme operational stability, and showed that the immobilization in activated carbon and in alumina allowed the reusability of the pancreatin for 5 times and 2 times, respectively.