Pembelajaran Makromolekul: Pembuatan Hidrolisat Protein

Penelitian ini bertujuan untuk membuat bahan pembelajaran fungsi enzim dalam metabolisme dan materi makromolekul di sekolah menengah melalui eksperimen pembuatan hidrolisat protein dengan papain. Diharapkan penelitian ini mampu memberi manfaat dalam membantu guru memberikan contoh nyata aplikasi peranan enzim dan materi makromolekul dalam kehidupan sehari-hari. Enzim yang digunakan dalam penelitian ini adalah protease. Protease dari pepaya dikenal sebagai papain. Hidrolisis protein dengan papain kasar menghasilkan hidrolisat protein. Pada penelitian ini, aktivitas papain diuji terhadap substrat kasein dan penentuan konsentrasi protein hasil hidrolisis dilakukan dengan metode Lowry. Hasil yang diperoleh adalah nilai aktivitas spesifik papain sebesar 7,93 U/mg,. Dari hasil kinetika reaksi enzim diperoleh nilai konstanta Michaelis-Menten (KM) papain 0,028% dengan Vmaks = 0.75 gram/menit. Kegiatan meneliti dengan topik pembuatan hidrolisat protein ini dapat dipakai sebagai bahan penyusunan model pembelajaran materi peranan enzim dan makromolekul di Sekolah Menengah Atas. Pengalaman meneliti seperti mengisolasi enzim kasar dari bahan alam dan menguji kinetika reaksi enzim merupakan praktik yang dapat diajarkan kepada siswa sehingga mereka dapat memahami pelajaran biologi mengenai peranan enzim dan makromolekul lebih baik. Penelitian ini juga dapat membantu atau menguatkan pemahaman materi ajar lain seperti laju reaksi, ikatan kimia, dan reaksi kimia organik sehingga tercipta pembelajaran biologi yang terpadu dengan pembelajaran lainnya

Isolasi Dan Karakterisasi Bakteri Penghasil Enzim Lipase Ekstraselulerdari Lumpur Aktif Instalasi Pengolahan Air Limbah Industri Tekstil

Lumpur aktif dari instalasi pengolahan air limbah industri tekstil mengandung berbagai jenis mikroorganisme antara lain mikroorganisme yang memiliki aktivitas lipase yang tinggi. Tujuan penelitian ini adalah mengisolasi dan mengkarakterisasi bakteri penghasil enzim lipase ekstraseluler dari lumpur aktif instalasi pengolahan air limbah industri tekstil. Tahapan penelitian yang dilakukan meliputi isolasi bakteri penghasil enzim lipase ekstraseluler dari lumpur aktif melalui skrining dengan media yang mengandung rodamin dan minyak zaitun, penentuan aktivitas enzim lipase dan karakterisasi lipase yang dihasilkan terhadap variasi temperatur, pH, dan pengaruh ion Ca2+. Hasil identifikasi secara mikrobiologi menunjukkan bahwa bakteri penghasil enzim lipase ekstraseluler dari lumpur aktif adalah spesies Erwiniachrysantemi. Enzim lipase ekstraseluler tersebut memiliki aktivitas 4,75 U/mL dengan temperatur optimum 40oC dan pH optimum 9. Penambahan ion Ca2+ tidak memberikan pengaruh berarti terhadap aktivitas enzim lipase

ISOLASI DAN KARAKTERISASI BAKTERI PENGHASIL ENZIM LIPASE EKSTRASELULERDARI LUMPUR AKTIF INSTALASI PENGOLAHAN AIR LIMBAH INDUSTRI TEKSTIL

Lumpur aktif dari instalasi pengolahan air limbah industri tekstil mengandung berbagai jenis mikroorganisme antara lain mikroorganisme yang memiliki aktivitas lipase yang tinggi. Tujuan penelitian ini adalah mengisolasi dan mengkarakterisasi bakteri penghasil enzim lipase ekstraseluler dari lumpur aktif instalasi pengolahan air limbah industri tekstil. Tahapan penelitian yang dilakukan meliputi isolasi bakteri penghasil enzim lipase ekstraseluler dari lumpur aktif melalui skrining dengan media yang mengandung rodamin dan minyak zaitun, penentuan aktivitas enzim lipase dan karakterisasi lipase yang dihasilkan terhadap variasi temperatur, pH, dan pengaruh ion Ca2+. Hasil identifikasi secara mikrobiologi menunjukkan bahwa bakteri penghasil enzim lipase ekstraseluler dari lumpur aktif adalah spesies Erwiniachrysantemi. Enzim lipase ekstraseluler tersebut memiliki aktivitas 4,75 U/mL dengan temperatur optimum 40oC dan pH optimum 9. Penambahan ion Ca2+ tidak memberikan pengaruh berarti terhadap aktivitas enzim lipase

Synthesis and Characterization of Polypyrole on Steel Gauze Electrode by Voltammetry Cyclic Method

The coating of polypyrrole (PPy) on steel gauze electrode by electropolymerization of pyrrole with voltammetry cyclic method has been investigated. The purpose of this research is a preliminary study the character of a steel gauze as working electrode which potential to electrodeposition on Polypyrrole (PPy) film based on literature. Based on cyclic voltammogram of PPy, the oxidation potential has been achieved at a potential range of 0V to 1V which compared to Ag/AgCl as reference electrode at a anodic peak current (Ipa) near 7 mA at a scan rate 100 mV/sec from a solution 0.05M of Py in the solution 0.1M of KCl as supporting electrolyte. The competition between PPy with some major component of steel gauze such as Fe, Zn, Cr or Mn occured, in the potential range 0 to 1V during the electropolimerization. The main component of steel gauze has been analyzed by X-Ray Fluoresence (XRF). PPy films can cover the surface of steel gauze with the number of ten cycles of polymer growth on the electrode surface have been studied with the anodic and cathodic peak current with the correlation coefficient 0.999 and 0.991 of the increasing the number of cycles at the potential range of 0.2V to 0.8V. The results of PPy film on the steelgauze electrode has been characterized by Fourier Transform Infra Red (FT-IR)

Analisis Komposisi Asam Lemak dari Mikroalga Laut Navicula salinicola

Indonesia is an aquatic country with potential biodiversity. One of the potential biodiversity is microalgae. Microalgae potential to be developed as a functional food with the characteristics of its fatty acids. The most fatty acids found in diatoms are myristic acid, palmitic acid, DHA and EPA. One of marine microalgae contain lot of fatty acids is diatom Navicula salinicola. This study was aim to analyze fatty acid composition of marine microalgae Navicula salinicola. Navicula salinicola was cultivated in Guillard medium with 2.5; 5; and 7.5 % of nitrogen composition and cultivated for 11 days. Dry biomass obtained from harvesting was used for the extraction. Extraction of lipid from microalgae used Bligh & Dyer method with 9,9%; 14.5%, and 17.5% of oil yield. Result of GC-FID analysis that were 6 types of fatty acids that identified are palmitic acid, myristic acid, pentadecanoic acid, stearic acid, palmitoleic acid and eicosapentanoic acid, EPA. The highest fatty acid was palmitic acid with fatty acids percentage were 64.04%; 65.03%; and 53.55% respectively

Diaminoalkane as Spacer Arm between Polystyrene and - Cylodextrin in Affinity Chromatography for -Amylase Separation

ABSTRACT Stationary phase design in affinity chromatography has to fulfill at least two requirements: non-specific interaction between solid support and or spacer arm and protein target or others is minimal and specific interaction between ligand and protein target is maximal. In this study, stationary phases that consist of polystyrene (PS) as solid support, diaminoalkane as spacer arm and with and without βCD as a ligand are performed in α-amylase separation. Therefore, the research was carried out in two steps; stationary phase preparation and adsorption parameter determination towards α-amylase. Stationary phases that consist of PS, 1,6-diaminohexane and βCD (PS-DAH-βCD) and without βCD (PS-DAH) were synthesized. Stationary phase structure was confirmed by FTIR, , respectively. Due to adsorption parameters, PS-DAP-βCD offer the best adsorption capacity and selectivity as stationary phase in affinity chromatography for α-amylase separation

SINTESIS DAN KARAKTERISASI POLIPIROL PADA ELEKTRODA KERJA KASA BAJA DENGANMETODE VOLTAMETRI SIKLIK

SINTESIS DAN KARAKTERISASI POLIPIROL PADA ELEKTRODA KERJA KASA BAJA DENGANMETODE VOLTAMETRI SIKLIK. Telah dilakukan penelitian pelapisan polipirol pada elektroda kerja kasa baja denganmetode elektropolimerisasi pirol secara voltametri siklik.Tujuan penelitian inimerupakan studi awal mempelajari karakter kasa baja yang berpotensi sebagai elektroda kerja tempat elektrodeposisi film polipirol (PPy) berdasarkan literatur. Berdasarkan voltamogram siklik PPy, potensial oksidasi PPy dicapai pada rentang potensial 0V hingga 1V dibandingkan terhadap elektroda pembandingAg/AgCl pada arus puncak anodik (Ipa) mendekati 7 mA, dengan laju pindai 100 mV/detik dari larutan pirol 0,05 M dalam pelarut KCl 0,1M sebagai elektrolit pendukung. Pada rentang potensial tersebut selama proses elektropolimerisasi, selain dicapai potensial anodik PPy, terjadi persaingan dengan munculnya potensial anodik dari komponen utama kasa baja yaitu Fe, Zn, Cr atau Mn. Komponen utama yang terdapat dalam kasa baja telah dianalisis dengan X-Ray Fluorescence (XRF). Pelapisan PPy mampu menutupi permukaan kasa baja dengan pertumbuhan polimer sebanyak 10 siklus pada permukaan elektroda dengan mempelajari koefisien korelasi peningkatan arus anodik R = 0,999 dan peningkatan arus katodik R =0,991 terhadap bertambahnya jumlah siklus pada rentang potensial 0,2V hingga 0,8V. Hasil pelapisan film PPy yang menutupi permukaan kasa baja telah dikarakterisasi dengan Fourier Transform Infra Red (FT-IR)

A new group of glycoside hydrolase family 13 α-amylases with an aberrant catalytic triad

α-Amylases are glycoside hydrolase enzymes that act on the α(1→4) glycosidic linkages in glycogen, starch, and related α-glucans, and are ubiquitously present in Nature. Most α-amylases have been classified in glycoside hydrolase family 13 with a typical (β/α)8-barrel containing two aspartic acid and one glutamic acid residue that play an essential role in catalysis. An atypical α-amylase (BmaN1) with only two of the three invariant catalytic residues present was isolated from Bacillus megaterium strain NL3, a bacterial isolate from a sea anemone of Kakaban landlocked marine lake, Derawan Island, Indonesia. In BmaN1 the third residue, the aspartic acid that acts as the transition state stabilizer, was replaced by a histidine. Three-dimensional structure modeling of the BmaN1 amino acid sequence confirmed the aberrant catalytic triad. Glucose and maltose were found as products of the action of the novel α-amylase on soluble starch, demonstrating that it is active in spite of the peculiar catalytic triad. This novel BmaN1 α-amylase is part of a group of α-amylases that all have this atypical catalytic triad, consisting of aspartic acid, glutamic acid and histidine. Phylogenetic analysis showed that this group of α-amylases comprises a new subfamily of the glycoside hydrolase family 13

Domain Motion in 3-isopropylmalate dehydrogenase: A Strategy to Enhance its Thermal Stability

In order to elucidate the thermal properties of Thermus thermophilus 3-isopropylmalate dehydrogenase, mutant structures with mutations at the C-terminus were compared with each other. The structural movement can be anticipated from the structural changes among mutants in regions of a minor groove and pillar. Our previous studies revealed that the open-close movement of the active site groove antagonizes to that of the minor groove (like a paperclip) and the thermostability of the enzyme increases when the active site groove is closed. In the present study, it is shown that the motion of the enzyme mainly occurs in the first domain and strand D in the pillar structure is a hinge-bending region of the movement. The motion of the first domain to expand the minor groove may close the active site groove suggesting a mechanism for the enhanced thermal stability of 3-isopropylmalate dehydrogenase