Caracterização por ressonância magnética nuclear de sucos de maçã obtidos por preparações enzimáticas

In this work, ¹H Nuclear Magnetic Resonance (¹H NMR) was employed to evaluate changes in apple juice in response to the addition of Panzym® Yieldmash and Ultrazym® AFP-L enzymatic complexes and compare it with premium apple juice. The juice was processed at different temperatures and concentrations of enzymatic complexes. The differences in the results were attributed mainly to the enzyme concentrations, since temperature did not cause any variation. A quantitative analysis indicated that the concentration of fructose increased while the concentrations of sucrose and glucose decreased in response to increasing concentrations of the enzymatic complexes.

Biochemical characterisation of lipase from a new strain of Bacillus sp. ITP-001

Lipases are characterised mainly by catalytic versatility and application in different industrial segments. The aim of this study was to biochemically characterise a lipase from a new strain of Bacillus sp. ITP-001. The isoelectric point and molecular mass were 3.12 and 54 kDa, respectively. The optima lipase activity was 276 U g-1 at pH 7.0 and a temperature of 80 ºC, showing greater stability at pH 5.0 and 37 ºC. Enzymatic activity was stimulated by various ions and pyridine, and inhibited by Cu+ and ethanol. The values of Km and v max were 105.26 mmol and 0.116 mmol min-1 g-1, respectively determined by the Eadie-Scatchard method.

Efeito do teor de umidade sobre o pré-tratamento a vapor e a hidrólise enzimática do bagaço de cana-de-açúcar

The effect of moisture content in the steam treatment and enzymatic hydrolysis of sugarcane bagasse was evaluated. Steam treatment was perfomed at 195-210 ºC for 4-8 min using cane bagasse with moisture contents in the range 16-100 wt% (dry basis). Increased moisture contents not only had a positive influence in recovery of main cane biomass components but also resulted in better substrates for enzymatic hydrolysis. As a result, drying is not required for optimal pretreatment and enzymatic hydrolysis of sugarcane bagasse, which can be processed into second generation ethanol immediately after crushing and hot water washing.

Hydrolytic activity of bacterial lipases in amazonian vegetable oils

The data presented describe the development of an enzymatic process in vegetable oils. Six bacterial lipases were tested for their ability to hydrolyze. For each lipase assay, the p-NPP method was applied to obtain maximum enzymatic activities. The lipase from Burkholderia cepacia (lipase B-10) was the most effective in buriti oil, releasing 4840 µmol p-NP mL-1. The lipase from Klebsiella variicola (lipase B-22) was superior in passion fruit oil, releasing 4140 µmol p-NP mL-1 and also in babassu palm oil, releasing 2934 µmol p-NP mL-1. Research into the bioprocessing of oils aims to provide added value for this regional raw material.

Enzyme loading dependence of cellulose hydrolysis of sugarcane bagasse

The enzymatic hydrolysis of steam-pretreated sugarcane bagasse, either delignified or non-delignified, was studied as a function of enzyme loading. Hydrolysis experiments were carried out using five enzyme loadings (2.5 to 20 FPU/g cellulose) and the concentration of solids was 2% for both materials. Alkaline delignification improved cellulose hydrolysis by increasing surface area. For both materials, glucose concentrations increased with enzyme loading. On the other hand, enzyme loadings higher than 15 FPU/g did not result in any increase in the initial rate, since the excess of enzyme adsorbed onto the substrate restricted the diffusion process through the structure.

Especiação de cobre e zinco em urina: importância dos metais em doenças neurodegenerativas

Metals such as copper and zinc are essential for the development and maintenance of numerous enzymatic activities, mitochondrial functions, neurotransmission, and also for memorization and learning. However, disruption in their homeostasis can cause neurodegenerative disorders such as the Alzheimer and Parkinson diseases. In this work, the speciation of copper and zinc in urine samples was carried out. To this end, free and total metal concentrations were determined by square wave anodic stripping voltammetry using a glassy carbon electrode coated with bismuth film. The digestion of the samples was performed in a microwave with the addition of oxidant reagents.

Biochemical properties of Bacillus sp. ITP-001 lipase immobilized with a sol gel process

This work presents biochemical characterization of a lipase from a new strain of Bacillus sp. ITP-001, immobilized using a sol gel process (IB). The results from the biochemical characterization of IB showed increased activity for hydrolysis, with 526.63 U g-1 at pH 5.0 and 80 ºC, and thermal stability at 37 ºC. Enzymatic activity was stimulated by ions such as EDTA, Fe+3, Mn+2, Zn+2, and Ca+2, and in various organic solvents. Kinetic parameters obtained for the IB were Km = 14.62 mM, and Vmax = 0.102 mM min-1 g-1. The results of biochemical characterization revealed the improved catalytic properties of IB.

Atividade de extratos de Arrabidaea chica (Humb. & Bonpl.) Verlot obtidos por processos biotecnológicos sobre a proliferação de fibroblastos e células tumorais humanas

Arrabidaea chica (H&B) Verlot is a plant popularly known as Pariri and this species is a known source of anthocyanins, flavonoids and tannins. This report describes an approach involving enzymatic treatment prior to extraction procedures to enhance A chica crude extract anticancer activity. Anticancer activity in human cancer cell lines in vitro using a 48 h SRB cell viability assay was performed to determine growth inhibition and cytotoxic properties. The final extraction yield without enzyme treatment was higher (24.28%) compared to the enzyme-treated material (19.03%), with an enhanced aglycones anthocyanin ratio as determined by HPLC- DAD and LC-MS with direct infusion.

Produção de concentrados de ácidos graxos por hidrólise de óleos vegetais mediada por lipase vegetal

The aim of this work was to verify the ability of enzymatic crude extract from dormant castor bean seeds to yield concentrated fatty acids by hydrolysis of polyunsaturated vegetable oils such as corn and sunflower. The enzymatic extract exhibited higher activity towards corn oil, which was selected for further studies to determine optimum hydrolysis conditions by factorial design. Maximum hydrolysis percentage (≈84%) was reached at 60% wt. oil:buffer acetate 100 mM pH 4.5, 33 ºC and 5.0% wt. of crude extract after 70 min of reaction. These results suggest that the use of low-cost lipase from castor bean seeds has potential for oil hydrolysis.

Fatos e tendências da biocatálise

Brazil is renowned for its biodiversity; however, its economy is based on exotic plants, extraction and unsustainable use of natural resources. This issue was addressed in a recent QN review entitled "Chemistry without Borders." In order to explore the potential of Brazilian biodiversity fully, sustainable development is required in key technological areas, such as biotechnology. This research field is consistent with the green chemistry and white technology principles. Therefore, biotechnology is a sustainable alternative to conventional technologies and is expected to account for 20% of global chemicals by 2020. Brazil is the second largest grower of biotech crops and biodiesel, but its main activities rely on the fermentative process. In order to stimulate the national biotechnology development, the Brazilian Federal Government launched a national policy for biotechnology in 2007 and the National Committee of Biotechnology was created. Among the outstanding biotechnological processes, biocatalysis is one of the most important alternatives to conventional processing, and this field has changed dramatically with the advent of recombinant DNA technology in the 1970s, when large quantities of enzymes were accessible. The direct evolution methodology in the 1990s was a breakthrough and allowed tailoring of enzymes possessing high stability and stereoselectivity. However, about 60 years after the first industrial enzymatic biotransformation of steroids, the full potential of biocatalysis is far from being achieved. Future challenges in this field concern the multienzyme cascade reactions associated with optimized chemoenzymatic processes, and some recent industrial application of biocatalysts are also highlighted in this perspective.

A influência da piperina na biodisponibilidade de fármacos: uma abordagem molecular

Piperine is the major alkaloid of Piper nigrum Linn., used as a spice and in folk medicine. We present a molecular docking study supporting experimental data on the enhancement in bioavailability of propranolol, theophylline, phenytoin, nevirapine, nimesulide, pyrazinamide, carbamazepine, and spartein in the presence of piperine. The complex formed with piperine and CYP3A4 was shown to be the most stable of all, with a binding energy of -8.60 kcal/mol. This explains the related mechanism of drug-herb interaction, since the better anchoring of piperine in the active site of CYP3A4 can hinder the drug-enzyme interaction, thereby increasing the bioavailability of the drugs studied.

Biocatálise heterogênea em fase sólido/gás: princípios e aplicações

Enzymatic conversion of gaseous substrates into products in aquo-restricted media, using enzymes or whole cells (free and immobilized) as biocatalysts, constitutes a promising technology for the development of clearer processes. Solid-gas systems offer high production rates for minimal plant sizes, allow important reduction of treated volumes, and permit simplified downstream processes. In this review article, principles and applications of solid-gas biocatalysis are discussed. Comparisons of its advantages and disadvantages with those of the organic- and aqueous-phase reactions are also presented herein.

Glicólise do poli(3-hidroxibutirato) por via enzimática

Poly(3-hydroxybutyrate), PHB, is a polymer with broad potential applications because of its biodegradability and biocompatibility. However, its high crystallinity is a limiting factor for many applications. To overcome this drawback, one strategy currently employed involves the reduction of the molecular weight of PHB with the concomitant formation of end-functionalized chains, such as those obtained via glycolysis. The glycolysis of PHB can be catalyzed by acid, base, or organometallic compounds. However, to our knowledge, there are no reports regarding PHB glycolysis catalyzed enzymatically. Among the major types of enzymes used in biocatalysis, the lipases stand out because they have the ability to catalyze reactions in both aqueous and organic media. Thus, in this study, we performed the enzymatic glycolysis of PHB using the lipase Amano PS (Pseudomonas cepacia) with ethane-1,2-diol (ethylene glycol) as the functionalizing agent. The results indicated that the glycolysis was successful and afforded hydroxyl-terminated oligomeric PHB polyols. Nuclear magnetic resonance spectra of the products showed characteristic signals for the terminal hydroxyl groups of the polyols, while thermogravimetric and differential scanning calorimetry analyses confirmed an increase in the thermal stability and a decrease in the crystallinity of the polyols compared with the starting PHB polymer, which were both attributed to the reduction in the molecular weight due to glycolysis.

Inmovilización de enzimas lignocelulolíticas en nanopartículas magnéticas

Due to the need for more efficient, economical and environmentally-friendly technological processes, the use of enzymes has increased. However, reuse of enzymatic hydrolytic complex is required. The immobilization of enzymes provides a basis for stability and allows their reuse reflected in aspects of economic feasibility. Magnetic nanoparticles are a promising supports since their magnetic character allows retrieval by applying an external magnetic field. This article presents an analysis and discussion of methods of biocatalyst immobilization, emphasizing lignocellulolytic enzymes immobilized in magnetic nanoparticles and their applications for the production of high-value compounds such as bioethanol.

Epoxidação do β-cariofileno com lipases imobilizadas em gel de ágar

The immobilization of enzymes and microorganisms on solid supports has been developed in recent years. These biocatalysts may be used in organic media allowing their storage and reuse, thus reducing costs of the process. Herein, lipases from various sources were immobilized in agar gel and used as catalysts in the chemo-enzymatic epoxidation of β-caryophyllene. Several experimental parameters, such as the use of different organic solvents including ionic liquids, time, temperature, and agitation rate were evaluated. The mono-epoxide was obtained as a single product. The best result was achieved using immobilized F-AP15 lipase, forming the corresponding β-caryophyllene epoxide at a conversion of 96% in an 8h reaction at 35 ºC.