Hasil Pencarian  ::  Simpan CSV :: Kembali

Abstrak :
Penyakit kardiovaskular masih menjadi salah satu masalah kesehatan global dan merupakan penyebab kematian tertinggi di berbagai belahan dunia. Penyakit ini umumnya disebabkan oleh penyempitan pembuluh darah akibat penumpukan kolestrol. Untuk mendeteksi kolestrol umumnya digunakan biosensor yang menggunakan enzim sehingga memerlukan biaya yang mahal. Oleh karenanya, penelitian ini bertujuan untuk mengembangkan sensor non-enzimatik untuk kolestrol yang berbasis nanokomposit β-siklodekstrin termodifikasi sitrat (BCD-CIT) dengan nanopartikel Fe3O4 melalui studi elektrokimia dan komputasi. Pada penelitian ini, nanokomposit BCD-CIT/Fe3O4 disintesis dengan menggunakan teknik ko-presipitasi dan hasil sintesis dikarakterisasi menggunakan instrumentasi SEM, XRD, dan FTIR, yang mengkonfirmasi bahwa partikel nanokomposit telah terbentuk dengan diameter 13,22 nm. Penentuan kadar kolesterol melalui studi elektrokimia dilakukan dengan menggunakan metode voltametri siklik (CV) dengan potensial -0,6 volt hingga +0,6 volt dan laju pindai (scan rate) 50 mV/s pada SPCE sebagai elektrodanya. Hasil pengukuran kadar kolesterol pada parameter optimum (jumlah nanokomposit 2 persen (w/w), waktu kontak 10 menit, PBS pH 7.4, dan konsentrasi MB 100 mM) diperoleh bahwa persamaan regresi untuk kurva kalibrasi untuk puncak arus anodik dan puncak arus katodik pada konsentrasi 0-125 μMdiperoleh dengan linieritas yang baik (R2>0.97). Selain itu, sensor menunjukkan sensitivitas yang tinggi, dilihat dari kemiringan slope yang dihasilkan. Dari studi komputasi dapat dikonfirmasi bahwa senyawa kolesterol membentuk kompleks inklusi dengan BCD-CIT dan BCD yang lebih stabil dibandingkan dengan senyawa metilen biru dan interferensi lainnya, dimana hasil simulasi penambatan molekul menunjukkan bahwa senyawa kolesterol secara berturut-turut memiliki ΔGbinding sebesar -6,4 kcal/mol dan -5,7 kcal/mol. Pada akhirnya, sensor non-enzimatik yang dikembangkan pada penelitian ini akan diujicobakan terhadap yogurt sebagai sampel untuk mengetahui kemampuan sensor ini pada sampel nyata. Cardiovascular disease (CVD) still remains as a major global health problems and currently ranks as the highest cause of death in various parts of the world, CVD is generally caused by narrowing of blood vessels due to cholesterol buildup. However, the cholesterol sensor that commonly used today are enzyme-based, which require specific treatments and expensive. This research aims to develop non-enzymatic sensors for cholesterol based on citrate modified b-cyclodextrin (BCD-CIT) and Fe3O4 nanocomposite using electrochemical and computational studies. In this study, BCD-CIT/Fe3O4 nanocomposite was successfully synthesized using co-precipitation technique, which the characterization results from SEM, XRD, and FTIR confirmed the formation of the nanoparticles with a diameter of 13.22 nm. Moreover, the determination of cholesterol levels through electrochemical studies was carried out using the cyclic voltammetry method (CV) with a potential of -0.6 volts to +0.6 volts and scan rate of 50 mV/s at SPCE as the electrodes. The measurement results at optimized parameters (2% (w/w) nanocomposite weight, contact time of 10 minutes, PBS pH 7.4, and MB concentration of 100 mM) in the cholesterol concentration ranged at 0-125 uM showed that the calibration curve of anodic and cathodic peak current were obtained with good linearity (R2>0.97). In addition, the sensor also exhibited high sensitivity, judged from the slope that resulted from the calibration curve. Furthermore, the computational study through molecular docking simulation confirmed that cholesterol formed the most stable complexes with both BCD and BCD-CIT compared to other compounds, including methylene blue and its interference, which ΔGbinding of the complexes was obtained at -6.4 kcal/mol and -5.7 kcal/mol, respectively. Finally, this non-enzymatic sensor which developed in this study will be tested further on yogurt to assess the capability and selectivity of BCD-CIT/Fe3O4 nanocomposite as the cholesterol sensor.

Abstrak :
ABSTRAK
Penelitian ini bertujuan untuk mendapatkan enzim selulase dari kapang terpilih untuk pembuatan selulosa mikrokristal dari kulit buah kapuk. Alfa selulosa didapatkan melalui biodelignifikasi dan enzim selulase murni diperoleh dari galur kapang terpilih. Selulosa mikrokristal didapatkan melalui hidrolisis enzimatis dengan enzim selulase yang telah dimurnikan, lalu diidentifikasi dengan analisa kualitatif Fourier transformed infrared spectroscopy (FTIR), dan differential scanning calorimetry (DSC), diikuti oleh karakterisasi selulosa mikrokristal seperti x-ray diffraction (XRD), analisis ukuran dan distribusi partikel, dan pengukuran scanning electron microscope-energy dispersive x-ray (SEM-EDX). Hasil penelitian menunjukkan bahwa biodelignifikasi terbaik dilakukan pada suhu 40˚C menghasilkan14,88% α-selulosa. Penicillium sp. sebagai kapang terpilih memiliki aktivitas selulase tertinggi dengan indeks selulolitik 4,83 dan aktivitas selulase sebesar 0,04299 U/mL. Fraksi pertama digunakan untuk hidrolisis memiliki aktivitas tertinggi yaitu 649,68 mU/mL. Hasil identifikasi FTIR menunjukkan kemiripan diagram dengan Avicel PH 101 dengan titik lebur 244,580˚C. Karakterisasi XRD menunjukkan kristalinitas pada 2 puncak 2Ɵ (deg) nilai 22,58 dengan intensitas 634 dan nilai 21,85 dengan intensitas 51. Susut pengeringan 3,74%, derajat keasaman pH 7,0, ukuran partikel antara 13,06 hingga 196,79μm, kerapatan serbuk ruah 0,111 g/cm3, serbuk mampat 0,235 g/cm3, laju alir cukup baik, SEM-EDX menunjukkan bentuk morfologi selulosa mikrokristal kulit buah kapuk berbentuk memanjang. Selulosa mikrokristal kulit buah kapuk telah menunjukkan karakteristik yang berbeda dengan referensi dan dapat dikembangkan lebih lanjut.

---

ABSTRACT
This study aims to obtain cellulase enzymes from selected molds for microcrystalline cellulose preparation from α-cellulose of kapok pericarpium. Alpha cellulose was obtained by biodelignification and the purified cellulase was obtained from selected mold. The Microcrystalline cellulose that obtained from enzymatic hydrolysis then identified by qualitative analysis, Fourier transformed infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC), followed by characterization of microcrystalline cellulose includes X-Ray Diffraction (XRD), Particle Size and Distribution Analysis (PSA), and Scanning Electron Microscope-Energy Dispersive X-ray (SEM-EDX). Biodelignification carried out at a temperature of 40C produced 14.88% α-cellulose, Penicillium sp. as the selected mold had the highest cellulase activity with a cellulolytic index of 4.83 and cellulase activity of 0.04299 U/mL. The first fraction used for hydrolysis had the highest activity of 649.68 mU/mL. FTIR identification showed a similarity with Avicel PH 101 with a melting point of 244.580C. XRD characterization was showed the crystallinity at 2 peaks 2Ɵ (deg) 22.58 with intensity 634 and 21.85 with intensity 51. Loss on drying was 3.74%, pH was 7.0, particle size ranged from 13.06 to 196.79 um, bulk density and tapped density were 0.111 g/cm3 and 0.235 g/cm3, the flow rate character is quite good, and SEM-EDX was showed that the morphological shape of the microcrystalline cellulose of the kapok pericarpium is elongated. Microcrystalline cellulose has shown a difference in characteristic and can be furthered.

Abstrak :

Penelitian ini bertujuan untuk menguji pertumbuhan Rhizopus azygosporus UICC 539 pada medium Potato Sucrose Agar (PSA) pada berbagai suhu dan kemampuan dalam mendegradasi tributirin 1% (v/v) dan 2% (v/v) pada berbagai suhu. Blok agar (diameter 6 mm) mengandung R. azygosporus UICC 539 2x10⁶ CFU/mL pada medium PSA umur 5 hari di suhu 30°C digunakan untuk uji pertumbuhan dan kemampuan degradasi tributirin 1% (v/v) dan 2% (v/v). Suhu pengujian pertumbuhan yaitu 30, 35, 40, 45, 50, 55, dan 60°C pada PSA selama 5 hari. Pengujian kemampuan R. azygosporus UICC 539 mendegradasi tributirin dilakukan pada medium tributyrin agar selama 3 hari dan 5 hari.  Medium tributyrin agar tanpa biakan digunakan sebagai kontrol. Hasil pengujian menunjukkan pertumbuhan R. azygosporus UICC 539 pada medium PSA ditandai dengan adanya miselium berwarna putih kecokelatan, bentuk dan tekstur filamen serta sporulasi. Rhizopus azygosporus UICC 539 dapat tumbuh pada suhu 30, 35, 40, 45, dan 50°C tetapi tidak dapat tumbuh pada suhu 55°C dan 60°C. Degradasi tributirin ditandai dengan adanya zona bening di sekitar koloni, dan dinyatakan dengan nilai enzymatic index (EI), yaitu R/r dengan R adalah diameter zona bening dan r adalah diameter koloni. Adanya zona bening mengindikasikan aktivitas lipolitik pada medium tributirin. Rhizopus azygosporus UICC 539 dapat mendegradasi tributirin 1% dan 2% di suhu 30, 35, 40, 45, dan 50°C. Nilai EI tertinggi yaitu sebesar 4,17 pada konsentrasi 1% suhu 50°C pada inkubasi hari ke-5. 

---

This study aims to detect the growth temperature of Rhizopus azygosporus UICC 539 on Potato Sucrose Agar (PSA) and the ability of R. azygosporus UICC 539 to degrade 1% (v/v) and 2% (v/v) tributyrin at various temperatures. Agar blocks (6 mm diameter) which contained R. azygosporus UICC 539 at 2x10⁶ CFU/mL from 5-days old in PSA at 30°C were used for growth temperature test and tributyrin degradation assay. Growth temperature test was carried out on PSA at 30, 35, 40, 45, 50, 55, and 60°C for 5 days. Tributyrin degradation assay was carried out on 1% and 2% tributyrin agar for 3 days and 5 days. Tributyrin agar without culture was used as a control. Rhizopus azygosporus UICC 539 showed growth on PSA by the presence of brownish white mycelium, filamentous shape, wooly texture, and sporulation. The growth temperature of R. azygosporus UICC 539 was 30, 35, 40, 45, and 50°C but the fungus was not able to grow at 55°C and 60°C. Tributyrin degradation was shown by the presence of clear zones around the colony. The tributyrin degrading ability was calculated using enzymatic index (EI): R/r, R was the diameter of the clear zone and r was the diameter of the colony. Rhizopus azygosporus UICC 539 degraded 1% and 2% tributyrin at 30, 35, 40, 45, and 50°C. Clear zone indicated lipolytic activity by R. azygosporus UICC 539. The highest EI value was 4.17 at 1% tributyrin at 50°C on day-5.

Abstrak :
Penelitian ini bertujuan untuk menguji kemampuan R. azygosporus UICC 539 dalam mendegradasi skimmed milk 1% (b/v) dan 2% (b/v) di suhu 30˚, 35˚, 40˚, 45˚, dan 50˚, 55˚, dan 60˚C. Blok agar (diameter 6 mm) mengandung 106 sel/mL R. azygosporus (umur 5 hari, pada Potato Sucrose Agar, PSA, di suhu 30˚C) digunakan untuk pengujian. Blok agar berisi biakan ditumbuhkan pada Czapek Dox Agar (CDA) modifikasi tanpa sumber karbon yang telah ditambahkan skimmed milk 1% (b/v) dan 2% (b/v) serta Victoria Blue 20% (b/v) sebagai indikator. Medium CDA modifikasi berisi blok agar diinkubasi selama 5 hari di suhu 30˚, 35˚, 40˚, 45˚, dan 50˚, 55˚, dan 60˚C. Medium CDA modifikasi tanpa kapang sebagai medium kontrol. Indikasi degradasi skimmed milk oleh R. azygosporus UICC 539 ditunjukkan dengan terbentuknya zona bening di sekitar koloni. Kemampuan kapang mendegradasi skimmed milk dinyatakan dengan nilai Enzymatic Index (EI). Nilai EI dihitung menggunakan rumus R/r, yaitu R adalah diameter zona bening dan r adalah diameter koloni. Hasil menunjukkan R. azygosporus UICC 539 mendegradasi skimmed milk 1% dan 2% dengan terbentuknya zona bening. Kemampuan R. azygosporus UICC 539 mendegradasi skimmed milk dipengaruhi oleh variasi konsentrasi substrat dan suhu inkubasi, yang ditunjukkan dengan nilai Enzymatic Index (EI) yang bervariasi. ......This study aims to test the ability of R. azygosporus UICC 539 to degrade 1% (w/v) and 2% (w/v) skimmed milk at 30˚, 35˚, 40˚, 45˚, dan 50˚, 55˚, and 60˚C. Agar block (6 mm diameter) containing 106 cells/mL of R. azygosporus (5 days old, on Potato Sucrose Agar, PSA at 30˚C) was used for the test. Fungi on the agar blocks were grown on modified Czapek Dox Agar (CDA) without a carbon source with the addition of 1% (w/v) or 2% (w/v) skimmed milk and Victoria Blue 20% (w/v) as an indicator. Modified CDA plates containing agar blocks were incubated at 30˚, 35˚, 40˚, 45˚, and 50˚, 55˚, and 60˚C for 3 and 5 days. Modified CDA without the fungus served as a control medium. Indication of skimmed milk degradation by R. azygosporus UICC 539 was shown by the formation of a clear zone around the colony. The ability of R. azygosporus UICC 539 to degrade skimmed milk was expressed by the Enzymatic Index (EI) value. The value was calculated using the formula: R/r, where R was the diameter of the clear zone and r was the diameter of the colony. The results showed that R. azygosporus UICC 539 degraded 1% and 2% skimmed milk by forming clear zones. Skimmed milk-degrading ability of R. azygosporus UICC 539 was influenced by variation of substrate concentrations and various incubation temperatures, resulting in differences of Enzymatic Index (EI) values.

Abstrak :
Cyclodekstrin glucanotranferase (CGTase) merupakan enzim yang mengkatalis produksi cyclodekstrin (CD). Penelitian ini menggunakan satu enzim CGTase komersial (Toruzyme M) yang dihasilkan secara rekayasa genetika menggunakan bakteri Bacillus yang telah disisipkan gen GTase dari bakteri termofilik Thermoanaerobbacter. Walaupun enzim in dapat menghasilkan alpa, beta, dan gamma siklodekstrin (a-CD, 0-CD, ^-CD), namun beta siklodekstrin merupakan produk terbesar. Hasil penelitian memperlihatkan bahwa reaksin enzim CGTase ini dengan pati sagu mentah sangat berbeda jika menggunakan pati sagu tergelatinkan. Temperatur anneling dan temperatur reaksi enzimatik dhetepkan pada 65°C. Kondisi optimum diperoleh pada pH 9 (bufer glisin-NaOH 0.05M), 15% (b/v) pati sagu dan 0.5% konsentrasi enzim. Total siklodekstrin maksimum (13.17 g/L) diperoleh selama 4 jam pada kelajuan agitasi 200 rpm.dengan perbandingan produk adalah 28%: 64%: 8% masing-masing untuk or-CD: /?-CD: y-CD. Adanya CuSO4, FeSO4 and Co(N03)2 didalam substrat mampu menghambat aktivitas enzim secara keseluruhan sedangan pemberian n-pentene dan etanol akan menghasilkan a-CD sebagai produk utama. Nilai Kmax dan Km CGTase Toruzyme?adalah 0.09 s /?-CD/min and 16.695 %(w/v), secara berurutan.

---

Cyclodextrin glucanotransferase (CGTase) is (he enzyme catalyzing the production of cyclodextrin (CD). This study was conducted using a commercial CGTase enzyme (ToruzymeT ) produced from genetically modified strain of Bacillus carrying the CGTase gene of Thermoanaerobbacter. Although this enzyme catalyses the formation of alpha, beta and gamma cyclodextrin from starch but beta-cyclodextrin is the major product. The result showed that the reaction behavior of the enzyme on ungelatinized sago starch was markedly different when compared with its reaction to gelatinized starch. Ungelatinised sago starch was annealed and reacted at 6S°C. The optimum condition for the reaction occurred at pH 9 (0.05M Glycine-NaOH buffer) with concentration enzyme and sago starch was 0.5%(v/v)and 15 %(w/v), respectively. The highest amount of total cyclodextrin (13.17 g/L) was produced when the reaction mixture was agitated at 200 rpm for 4 hours consisting of a-CD: /J-CD: y-CD at ratios of 28: 64: 8. The CGTase lost almost all its dextrinizing activity in the presence CuSO4, FeSO4 and Co(NO3)2 in substrate. Addition of n-pentane and ethanol to the reaction mixture, shifted the reaction toward an increased of yield of a-cyclodextrin and eventually becoming the main product of the reaction. The Kmax and Km value of CGTase Toruzyme? were 0.09 g /?-CD/min and 16.695 %(w/v), respectively.

Abstrak :
Helicobacter pylori (H. pylori) is a gram negative and pleomorphic bacteria taht able to change its morphology according to environment....

Abstrak :
Lecithin is needed as a bioemulsifier product in stabilizing agents for the food, pharmaceutical and cosmetic industries due to its renewability and as it is environmentally friendly. In the food industry, most of the emulsifiers used are the oil-in-water (O/W) type. Lecithin can be seen as a promising emulsifier product because it is extracted from egg yolk and modified by enzymatic hydrolysis reaction using the papain enzyme. This modification will change the molecular structure of the compound, which makes lecithin more stable in the oil-in-water type of emulsion. This study aims to determine the optimum amount of papain enzyme used in the hydrolysis reaction to achieve the most stable O/W lecithin emulsion type. The results show that the breaking of a single fatty acid chain from the structure of lecithin can be demonstrated by FTIR instrumentation. The fatty acids detected from the lecithin structure are shown at wavenumber 1699.45 cm-1 (C=O), 1231.44 cm-1 (C-O), 1422.45 cm-1 (C-O-H), 1092.85 cm-1 (C-C), 665.89 cm-1 (CH2), and 3400.57 (-OH in carboxylate). Determination of the modified lecithin yield was made by several tests, namely a stability test, and tests for acid value, surface tension and zeta potential. From the results of tests, the emulsion stability for the O/W type was achieved in modified-lecithin using a 4% papain enzyme dosage, with a stability duration of up to 31 hours. The lowest acid number was achieved in modified-lecithin using a 2% papain enzyme dosage with value of 10.40. The lowest surface tension was obtained in modified-lecithin using a 2% papain enzyme dosage with a surface tension value of 48.68 dyne/cm. The zeta potential of the modified-lecithin using a 2% papain enzyme had a value of -94.8 mV. These results show that the enzymatic hydrolysis of lecithin using a papain enzyme is clearly able to enhance the emulsifier properties of the lecithin produced.