Academic literature on the topic 'Enzimatic reactions'

Lipid terstruktur dengan medium chain fatty acid (MCFA) pada posisi luar dan polyunsaturated fatty acid (PUFA) pada posisi sn-2 memiliki nilai gizi dan absorbsi yang sangat baik. Dalam penelitian ini lipid terstruktur disintesis secara langsung melalui asidolisis enzimatis antara minyak ikan dan asam laurat. Reaksi dikatalisis oleh lipase dedak padi. Tujuan penelitian ini adalah mempelajari perilaku dari reaksi asidolisis enzimatik minyak ikan tuna dan asam laurat, dengan kajian pengaruh biokatalis lipase dedak padi terhadap hasil asidolisis. Target yang ingin dicapai berupa data-data teknis laboratorium untuk perancangan, scale-up dan pengoperasian proses yang meliputi kinetika reaksi, studi produktifitas asam lemak, kondisi operasi yang optimum dan analisa tekno-ekonomi. Hasil penelitian menunjukkan bahwa konsentrasi lipase dan suhu reaksi optimum berturut-turut 10% dan 50oC. Rasio mol optimum minyak ikan dan asam laurat adalah 1:10, dihasilkan inkorporasi asam laurat mencapai 62,8 mol%. Pada waktu inkubasi 12 jam, trigliserida menurun seiring dengan meningkatnya waktu inkubasi, sedangkan digliserida meningkat seiring dengan meningkatnya waktu inkubasi. Pada suhu reaksi di atas 50oC, trigliserida menurun seiring dengan meningkatnya suhu reaksi. Metode interesterifikasi ini cukup efektif untuk mensintesis lipid terstruktur spesifik. Lipase dapat digunakan dengan baik untuk sintesa Lipid Terstruktur dari minyak ikan tuna dengan asam laurat. Kondisi optimum reaksi adalah pada suhu 50oC, konsentrasi lipase 10%, perbandingan ratio substrat (Minyak ikan tuna : asam laurat) 1:10 selama 12 jam. Profil gliserida dari hasil asidolisis enzimatis adalah 78,1 % trigliserida, 32,2 % digliserida dan 11,9% monogliserida Lipase Rice Bran Biocatalystator For Asidolysis Process Tuna Oil And Lauric Acid Lipid structured with medium chain fatty acids (MCFA) in the outer position and polyunsaturated fatty acid (PUFA) in sn-2 position has excellent nutritional value and absorption. In this study structured lipids were synthesized directly through enzymatic acididisation between fish oil and lauric acid. The reaction was catalyzed by a specific lipase of 1.3 from the tertiary carotid rugose. The aim of this study was to study the behavior of enzymatic acidic reactions of tuna and lauric acid oils, with the study of the effect of rice bran biocatalyst on acidic acid yield. The targets to be achieved are technical laboratory data for design, scale-up and operation of processes including reaction kinetics, fatty acid productivity studies, optimum operating conditions and techno-economic analysis. The results showed that the optimum lipase concentrate and temperature of the reaction were 10% and 50oC, respectively. The mole ratio of fish oil and lauric acid was 1:10 in which the incorporation of lauric acid was 62,80% (mol). Incubation time, 12 h, triglyceride decreased with an increase in incubation time. In contrast, the diglyceride increased with an increase in incubation time. At temperature higher than 50oC, triglyceride decreased with an increase in reaction temperature. The methode of interesterification was proven to be effective in synthezed specific structured lipids. Lipase rice brand, can be used successfully for the synthesis of structured lipids from tuna oil with lauric acid. Optimum reaction temperature is 50oC, lipase concentration of 10%, the ratio of substrate ratio (tuna fish oil: lauric acid) 1:10 for time incubation 12 hours. Profile gliseride from results acidolysis enzymatic triglycerides were 78.1%, 32.2% 11.9% diglycerides and monoglycerides.

In line with the depletion of petroleum reserves from fossils, humans have forced people to look for alternative renewable energy sources. Nipah plant stems are organic material that contains a lot of lignocellulose. Cellulose in lignocellulose can be hydrolyzed to glucose to produce bioethanol. Problems arise because hydrolysis using pure cellulase requires relatively high costs, so it is necessary to find an alternative source of cheap cellulase. One of the cheap sources of cellulase is goat rumen fluid. Until now, there is not much information regarding the reaction kinetics and cellulase characteristics of goat rumen fluid. The purpose of this study was to isolate crude cellulase extract, determine the KM and Vmax values ​​and determine the optimum temperature and pH. The research was carried out at the Unsoed Agricultural Technology Laboratory. The samples used were seven rumen fluids. The study began with isolation followed by enzymatic kinetics studies. Fractionation was carried out by adding ammonium sulfate salt (50, 60,70, and 80 %), and centrifugation at 7,000 rpm at 4 oC for 15 minutes. Crude cellulase extract with the highest enzyme activity value was used for the study of enzymatic reaction kinetics and characterization. The crude cellulase resistance test to temperature was carried out at 45, 55 and 65 oC and the pH was carried out at pH 4, 5, 6, 7 and 8. The KM and Vmax values ​were determined by measuring the activity of crude cellulase extract at various concentrations of CMC (1, 1 ,5, 2, 2.5, and 3 %). The results showed that crude cellulase extract had an average specific activity of 1.7356 IU/mg. The highest enzyme activity was 0.9854 IU/ml. The optimum crude cellulase extract was at pH 6 with an activity of 1.1015 IU/ml and a temperature of 60 oC with an activity of 0.7829 IU/ml. At a CMC concentration of 2.5% crude cellulase extract had an activity of 0.3179 IU/ml with a Vmax value of 0.0045 IU/ml and a KM of 0.0252 %.

In line with the depletion of petroleum reserves from fossils, humans have forced people to look for alternative renewable energy sources. Nipah plant stems are organic material that contains a lot of lignocellulose. Cellulose in lignocellulose can be hydrolyzed to glucose to produce bioethanol. Problems arise because hydrolysis using pure cellulase requires relatively high costs, so it is necessary to find an alternative source of cheap cellulase. One of the cheap sources of cellulase is goat rumen fluid. Until now, there is not much information regarding the reaction kinetics and cellulase characteristics of goat rumen fluid. The purpose of this study was to isolate crude cellulase extract, determine the KM and Vmax values ​​and determine the optimum temperature and pH. The research was carried out at the Unsoed Agricultural Technology Laboratory. The samples used were seven rumen fluids. The study began with isolation followed by enzymatic kinetics studies. Fractionation was carried out by adding ammonium sulfate salt (50, 60,70, and 80 %), and centrifugation at 7,000 rpm at 4 oC for 15 minutes. Crude cellulase extract with the highest enzyme activity value was used for the study of enzymatic reaction kinetics and characterization. The crude cellulase resistance test to temperature was carried out at 45, 55 and 65 oC and the pH was carried out at pH 4, 5, 6, 7 and 8. The KM and Vmax values ​were determined by measuring the activity of crude cellulase extract at various concentrations of CMC (1, 1 ,5, 2, 2.5, and 3 %). The results showed that crude cellulase extract had an average specific activity of 1.7356 IU/mg. The highest enzyme activity was 0.9854 IU/ml. The optimum crude cellulase extract was at pH 6 with an activity of 1.1015 IU/ml and a temperature of 60 oC with an activity of 0.7829 IU/ml. At a CMC concentration of 2.5% crude cellulase extract had an activity of 0.3179 IU/ml with a Vmax value of 0.0045 IU/ml and a KM of 0.0252 %.

<p>The objectives of the research was to find the temperature and time of enzymatic hydrolysis reaction of coconut oil by lipase from Rhizomucor miehei as biocatalyze which could produce the highest free fatty acids. Enzymatic hydrolysis reaction was held at various of reaction temperature (35, 40, 45 dan 50oC) and reaction duration (6, 12, 18 and 24 hours). Enzymatic hydrolysis reaction was carried out in waterbath shaker on pH of 7.0 and enzyme concentration of 2.5% based on substrate weight. The hydrolysis products were monitored using TLC using hexane:diethyl eter:acetic acid = 80:20:1 as developing solvent on silica gel F254, 20 cm x 20 cm aluminium plat. The results showed that hydrolyzed coconut oil contained 5 spots, they were identified as 1 spot of triglyceride at upper, 1 spot of free fatty acid, 2 spots of diglyceride at the middle and 1 spot monoglyceride at the bottom. The condition of enzymatic hydrolysis reaction produce the highest of free fatty acid (37.10%) at 50°C of temperature for 24 hours.</p><p>ABSTRAK</p><p><br />Penelitian ini bertujuan untuk mengetahui suhu dan lama reaksi yang dapat menghasilkan asam lemak bebas (ALB) paling banyak pada proses hidrolisis minyak kelapa menggunakan biokatalis lipase dari Rhizomucor miehei. Hidrolisis dilakukan pada variasi suhu reaksi (35, 40, 45 dan 50oC) dan lama reaksi (6, 12, 18 dan 24 jam). Reaksi hidrolisis dilakukan dalam shaker waterbath dengan pH 7,0 dan kosentrasi enzim 2,5% dari berat substrat. Hasil hidrolisis dianalisis dengan kromatografi lapis tipis (KLT) menggunakan larutan pengembang campuran pelarut heksan:dietil eter:asam asetat = 80:20:1 pada pelat silica gel F254, pelat aluminium 20 cm x 20 cm. Hasil penelitian menunjukkan bahwa hasil hidrolisis minyak kelapa teridentifikasi lima spot yaitu satu spot trigliserida pada bagian atas, 1 spot asam lemak bebas, dua spot digliserida dan satu spot monogliserida pada bagian bawah. Kondisi hidrolisis minyak kelapa dengan lipase dari R. miehei untuk menghasilkan asam lemak bebas tertinggi yaitu pada suhu 50°C selama 24 jam yaitu sebanyak 37,10%.<br /><br /></p>

Anderson-Fabry disease (FD) is a X-linked lysosomal storage disorder, which involves glycosphingolipids metabolism. Specific treatment for FD has been available in the last two decades, after the development and commercialization of recombinant human alfa-galactosidase A. Since then enzyme replacement therapy (ERT) has changed the natural history of the disease. Two different enzymatic formulations are available: agalsidase alfa and agalsidase beta at different dosages. The safety and efficacy profiles are similar. ERT induces Gb3 deposits reduction in renal and cardiac biopsies, improves quality of life, reduces pain and GI symptoms, decreases left ventricular mass and slows down renal function decline. In case of organ involvement, clinical evidence confirms the need to treat all patients with enzyme therapy, both male and female. In all other clinical settings, the decision to start ERT is controversial, because of the extremely variable clinical manifestations of FD. However, data suggest a greater response to ERT if started as early as possible in any patients. Timely treatment appears to be effective in stabilizing and possibly delaying FD progression. ERT infusion reactions due to allergic hypersensitivity or IgG antibody development could occur but can be easily managed. In-hospital and at home infusions are possible. The wide genetic and phenotypic heterogeneity observed in all FD patients requires a tailored approach to treatment options. Patients should be referred to an expert multidisciplinary team for the long term management of this challenging disease.

Enzyme Replacement Therapy for Fabry Disease Anderson-Fabry disease (FD) is a X-linked lysosomal storage disorder, which involves glycosphingolipids metabolism. Specific treatment for FD has been available in the last two decades, after the development and commercialization of recombinant human alfa-galactosidase A. Since then enzyme replacement therapy (ERT) has changed the natural history of the disease. Two different enzymatic formulations are available: agalsidase alfa and agalsidase beta at different dosages. The safety and efficacy profiles are similar. ERT induces Gb3 deposits reduction in renal and cardiac biopsies, improves quality of life, reduces pain and GI symptoms, decreases left ventricular mass and slows down renal function decline. In case of organ involvement, clinical evidence confirms the need to treat all patients with enzyme therapy, both male and female. In all other clinical settings, the decision to start ERT is controversial, because of the extremely variable clinical manifestations of FD. However, data suggest a greater response to ERT if started as early as possible in any patients. Timely treatment appears to be effective in stabilizing and possibly delaying FD progression. ERT infusion reactions due to allergic hypersensitivity or IgG antibody development could occur but can be easily managed. In-hospital and at home infusions are possible. The wide genetic and phenotypic heterogeneity observed in all FD patients requires a tailored approach to treatment options. Patients should be referred to an expert multidisciplinary team for the long term management of this challenging disease.

Biodiesel is a fuel derived from renewable sources, wich can be used efficiently in petrodiesel engines. This study aims to produce biodiesel from tamanu oil enzymatically using the lipase enzyme. This enzimatic method has a high value product made during the production of biodiesel. Biodiesel production through the transesterification process with methanol reactant and alkaline catalysts has many weaknesses, namely the presence of a saponification reaction and it is difficult to separate because the catalyst is homogeneus. The result of this study indicate that tamanu oil has been seccessfully converted into biodiesel with an optimum oil : methanol molar ratio of 1:5 and a yield precentage of 87,67% with a methyl ester content of 97,37%

Polymerase chain reaction (PCR) adalah metode untuk amplifikasi (perbanyakan) primer oligonukleotida secara enzimatik berdasarkan urutan DNA spesifik. Teknik ini mampu memperbanyak sebuah urutan 105-106 kali lipat dari jumlah nanogram DNA template. Tujuan dari kegiatan ini adalah untuk mengetahui apakah alat thermal cycler tersebut dapat digunakan dengan baik untuk memperoleh hasil yang valid dalam melakukan pengujian deteksi KHV. Deteksi virus KHV dilakukan pada genom DNA hasil ekstraksi yang diamplifikasi dengan menggunakan Maxima hot start green PCR master mix dan diamplifikasi dengan thermal cycler PCR (Bio Rad). Primer yang digunakan adalah F:5’ –GAC ACC ACA TCT GCA AGG AG-3’ dan R:5’ –GAC ACA TGT TAC AAT GGT CGC-3’ dengan ukuran fragmen 290 bp. Uji kinerja pada alat thermal cycler (Bio Rad) menunjukkan performa hasil yang baik. Hasil visualisasi fragmen DNA KHV pada keseluruhan well teramplifikasi sempurna.

Polifenol-glukosida disintesis menggunakan CGTase yang berasal dari Nocardia sp. Sintesis polifenol-glukosida dilakukan dengan menggunakan resorsinol sebagai akseptor dan tepung sagu sebagai donor. Penelitian ini bertujuan untuk mensintesis senyawa polifenol-glukosida secara enzimatik menggunakan CGTase dari biakan Nocardia sp,menguji aktivitasnya sebagai senyawa antimikroba dan untuk mengetahui pengaruh senyawa polifenol-glukosida terhadap kerusakan morfologi sel dari biakan Bacillus subtilis. Polifenol–glukosida hasil reaksi transfer dimurnikan menggunakan kolom kromatografi yang berisi matriks oktadesil silica dan menggunakan eluen asam formatdalam methanol (40-90%). Produk yang sudah terpisah ditunjukkan sebagai noda tunggal pada plat kromatografi lapis tipis dengan nilai Rf mendekati nilai Rf standar arbutin. Nilai Rf dari produk transfer tersebut adalah sebesar 0,84 dan nilai Rf standar arbutin adalah sebesar 0.85. Polifenol-glukosida hasil sintesis menunjukkan aktivitasantimikroba terhadap biakan Bacillus subtilis dan Escherichia coli. Kata kunci : polifenol-glukosida, CGT-ase, Nocardia sp., Bacillus subtilis dan Escherichia coli AbstractPolyphenol-glucoside was synthesized by using CGTase derived from Nocardia sp. Synthesis polyphenol-glucoside of was done by using resorcinol as the acceptor and starch sago as the donor. This study aims to synthesized polyphenol-glucoside enzymatically using CGTase derived from Nocardia sp and to assay it’s activity as antimicrobial compound and to determine effect of polyphenol-glucoside on morphological damaging of Bacillus subtilis cells. The synthesized polyphenols-glucoside by transfer reaction was purified through column chromatography containing octadecyl silica matrix that was eluted with formic acid in methanol (40-90%). The separated product was demonstrated by single spot appearance on thin-layer chromatography plate with Rf value that was closed to standard of arbutin Rf. The Rf value of this transfer product was 0.84 while Rf value of arbutin as authentic standard was 0.85. The synthesized polyphenol-glucosie exhibited antimicrobial activity against Bacillus subtilis and Escherichia coli. Key words : Polyphenol-glucoside, CGT-ase, Nocardia sp., Bacillus subtilis and Escherichia coli.

<p>Sargassum plagyophyllum from Sargassaceae family contains various bioactive compounds, namely<br />phlorotannin which is reported as an antioxidant and tyrosinase inhibitor. Tyrosinase inhibitor and<br />antioxidant activity from seaweed powder that obtained from seaweed’s slurry have not been reported. Thus,<br />this study was aimed to obtain the best seaweed slurry and powder from S. plagyophyllum based on tyrosinase<br />inhibitor and antioxidant activity, so it can be used as active substance in skin lightening cosmetic formula.<br />S. plagyophyllum which prepared fresh and dried was processed into seaweed slurry and lyophilization<br />to form powder. Antioxidant activity which was determined by 2,2-Diphenyl-1-picrylhydrazyl (DPPH)<br />radical scavenging method found the IC50 values of ascorbic acid was 0.0035 mg/mL; fresh slurry 27.31<br />mg/mL; dried slurry 41.13 mg/mL; fresh powder 2.21 mg/mL; and dried powder 13.18 mg/mL. Moreover,<br />the tyrosinase inhibitory activity which was measured by enzimatic reaction with L-tyrosine as substrate<br />found IC50 values kojic acid 0.0076 mg/mL; fresh powder 4.97 mg/mL; and dried powder 11.35 mg/mL. Seaweed powder obtained from fresh ingredient is the most optimal result based on its tyrosinase inhibitor<br />and antioxidant activity, thus potential to be developed further as active substance for lightening cosmetic<br />formula.<br /><br /></p>

2006/2007
Next-generation DNA detection arrays are expected to achieve unprecedented sensitivity, reducing the minimum amount of genetic material that can be directly (PCR-free and label-free) and quantitatively detected, up to the single cell limit. To realize these goals, we propose a new method for the miniaturization of DNA arrays to the nano-scale, which has the unique capability of controlling the packing quality of the deposited bio- molecules. We used NanoGrafting, a nano-lithography technique based on atomic force microscopy (AFM), to fabricate well ordered thiolated single stranded (ss)-DNA nano-patches within a self-assembled monolayer (SAM) of inert thiols on gold surfaces. By varying the “writing” parameters, in particular the number of scan lines, we were able to vary the density of the supported DNA molecules inside the nano-patches in a controlled manner. Our findings can be resumed in two parts: 1) Combining accurate height and compressibility measurements, before and after hybridization, we demonstrate that high-density ss-DNA nanografted patches hybridize with high efficiency, and that, contrary to current understanding, is not the density of probe molecules to be responsible for the lack of hybridization observed in high density ss-DNA SAMs, but the poor quality of their structure. 2) Dpn II enzymatic reactions were carried out over nanopatches with different molecular density and different geometries. Using nanopatch height measurements we are able to show that the capability of the Dpn II enzyme to reach and react at the recognition site significantly depends on the molecular density in the nanopatches. In particular the inhibition of the reaction follows a step-wise fashion at relatively low DNA densities. These findings suggest that, due to the enzyme size, it is possible to tune the efficiency of an enzymatic reaction within surface-bound DNA nanostructures by changing only the crowding of DNA on the surface and without introducing any further physical or chemical variable.
XIX Ciclo
1979

Estudos recentes indicam que os peptídeos obtidos pela hidrolise enzimática da caseína podem apresentar atividades antioxidantes. Neste trabalho, previamente obteve-se os peptídeos através de hidrolise da caseína utilizando as enzimas Alcalase e Flavourzyme (4h, a 50ºC e pH 8), selecionando os que apresentaram as melhores características, in vitro, relativas à atividade antioxidante. A hidrolise enzimática utilizando a enzima Flavourzyme mostrou melhores resultados, com alto valor de proteína solúvel e conteúdo de aminoácidos livres, além de peptídeos de menor peso molecular do que com a Alcalase, como observado nas análises de cromatografia de permeação em gel e eletroforese em gel de poliacrilamida. Os peptídeos de caseína obtidos com a Flavourzyme também apresentaram melhores resultados utilizando o método ABTS na determinação da capacidade antioxidante. O hidrolisado obtido a partir da enzima Flavourzyme foi aplicado em produtos cárneos e em chocolate branco. Em produtos cárneos, os peptídeos de caseína (2.0%) inibiram, efetivamente, a peroxidação lipídica em carne moída (100%) e em carne mecanicamente separada de ave (CMS) (cerca de 20%) indicando que estes peptídeos podem ser utilizados nestes produtos, auxiliando na prevenção da formação de flavor desagradável e aumentando sua vida útil. Relativamente a sua aplicação em chocolate branco, esta adição teve o intuito de inibir escurecimento deste produto, fator considerado como limitante na sua vida-útil sendo conseqüência tanto de reações de escurecimento não enzimático quanto da oxidação de lipídeos. Os parâmetros que indicaram alteração lipidica e reações não enzimáticas foram mensurados em três diferentes amostras de chocolate branco: uma amostra com 0,2%, de manteiga de cacau, de antioxidante sintético Grindox 562, outra com 0,2%, de manteiga de cacau, dos peptídeos de caseína e a terceira amostra sem qualquer tipo de antioxidante. As amostras foram expostas a duas temperaturas diferentes: 20 ± 2 e 28 ± 2ºC. Os resultados das análises realizadas indicaram que as amostras armazenadas à temperatura de 20ºC apresentaram resultados significativamente melhores àqueles das amostras armazenadas à temperatura de 28ºC, relativos ao índice de acidez, à atividade de água, ao índice de peróxido, à cor e às substâncias reativas ao ácido tiobarbitúrico (TBARS), indicando melhor conservação deste produto. Também foi observado que a adição de quaisquer dos antioxidantes empregados não influenciou de forma significativa os resultados obtidos, evidenciandose assim, que o principal parâmetro responsável pelas alterações do chocolate branco em sua vida útil refere-se à temperatura de armazenamento a qual as amostras foram submetidas.
Recent studies indicate that peptides obtained by casein hydrolysis may have antioxidant activity. In this work, previous casein peptides were obtained by enzymatic hydrolysis using Alcalase and Flavourzyme (4h, at 50ºC and pH 8), selecting the ones that showed the best characteristics in vitro, related to the antioxidant activity. The enzymatic hydrolysis using Flavourzyme showed the best results, with higher soluble protein and free amino acid content and producing lower molecular weight peptides than Alcalase, as observed by gel permeation chromatography and polyacrylamide gel electrophoresis. Related to its application in meat products, casein peptides obtained with Flavourzyme also exhibited greater antioxidant capacity using the ABTS method. The casein hydrolyzed from Flavourzyme enzyme was applicated in ground beef homogenates, mechanically deboned meat (MDM) of poultry and white chocolate. In meat products, casein peptides (2.0%) effectively inhibited lipid peroxidation in ground beef homogenates (100%) and mechanically deboned meat (about 20%) of poultry. Casein peptides may be useful in meat processing as another naturally occurring antioxidant, helping to prevent off-flavor formation in meat products and increasing shelf life. In the use for white chocolate, the goal was to inhibit its browning, the main problems that limit the white chocolate’s shelf-life. Non-enzymatic browning reaction and lipid oxidation were involved directly in the browning of white chocolate. Thus, parameters which indicated fat alteration and non-enzymatic reactions were measured in three different samples of white chocolate. One sample with 0,2% of cocoa butter, with the synthetic antioxidant Grindox 562, other with 0,2% of cocoa butter, with the natural antioxidant and the third sample without any kind of antioxidant. The samples were exposed to two different temperatures: 20 ± 2 and 28 ± 2ºC. The results of the analysis made indicated that the samples stored at the temperature of 20ºC showed results significantly better to those samples stored at the temperature of 28ºC, related to the conservation of the white chocolate. Besides, the results indicated that the addition of any antioxidants employees has not influenced in a significant way the results obtained. Thus, it was evidenced that the main responsible parameter for the alterations of the white chocolate’s shelf-life is related to the storage temperature to which the samples were submitted.