Judul: Aktivitas dan Stabilitas Glukosa Dehidrogenase Escherichia coli yang Diimobilisasi pada Zeolit Cikembar
Abstrak: Glucose level in blood can be measured by using a glucose biosensor. Glucose biosensor commonly utilize glucose dehydrogenase (GDH) produced by microbes as the biological sensors. In this study, electrochemical method was used to measure the activity and stability of GDH from Escherichia coli ATCC25922 immobilized on Cikembar’s natural zeolite, in development of glucose biosensor. Natural zeolite as immobilization matrix was found to increase the activity and stability of the GDH. Optimization of immobilized E. coli cell’s GDH activity was carried cut with response surface method experimental design obtaining optimum conditions at 30 °C, pH 7, [glucose] 20.250 mM, [PQQ] 4.0686 μM, and 250 mg zeolite. Maximum GDH activity was obtained at [glucose] 60 mM, following Lineweaver-Burk equation with the value of 8.8289 mM for KM app and 1.2020μA for Imax app. The stability and activity of E. coli cell’s GDH was 60−70% for 24 hours. Base on these results, Cikembar’s natural zeolite can increase the activity and stability of the E. coli cell’s GDH, but the affinity and stability are still low or not maximum
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Judul: Stabilitas dan Efektivitas Biosensor Glukosa Menggunakan Escherichia coli Yang Diimobilisasi Pada Matriks Nanokomposit Zeolit
Abstrak: Biosensor combines the selectivity of biological recognition element and the sensitivity of the transducer. The application of biosensor as blood glucose measurer for diabetes mellitus patients uses purified enzyme as biological sensor. The substitution of purified enzyme with the microbial cells producing enzymes as biological sensor is carried out to overcome the weaknesses of purified enzyme such as the low stability of the enzyme activity and the high cost. This research was carried out to measure the activity of glucose dehydrogenase (GDH)–the enzyme reacting specifically with glucose as substrate and binding with both pyrolloquinoline quinone (PQQ) and Mg2+ ion as prosthetic group and activator respectively-which is exhibited by escherichia coli, using electrochemical methods Design of experiments only to optimalization the activity of GDH bacterial cells of e. coli is a method of surface response. Optimum conditions of activity of GDH derived cells of e. coli bacteria in the absence of a matrix of nanocomposite zeolite on the process of immobilization is the temperature of 30°C, pH 6, concentration of glucose 15 mM, the concentration of PQQ 3,050 μM. As for the optimum conditions for the activity of GDH bacterial cells of e. coli with matrix nanocomposite zeolite is the temperature of 30°C, pH 6, glucose concentration of 15 mM, the concentration of PQQ 3,050 μM, and nanocomposite zeolite 137,50 mg. The reaction catalyzed by GDH kinetics of Glucose Kinetics equation follows the Lineweaver-Burk. The value of KM app bacterial cells of e. coli with the larger of nanocomposite zeolite mM compared to 1,4580 without nanocomposite of zeolite matrix 0,720 mM. This shows that affinity GDH e. coli immobilization of glucose substrate without nanocomposite zeolite is greater compared to the matrix nanocomposite zeolite.GDH activity stability of bacterial cells is not much different compared with no matrix nanocomposite zeolite.
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Judul: Perumusan Strategi Bisnis Pt.Karana Line
Abstrak: PT. Karana Line adalah sebuah perusahaan pelayaran yang memberikan layanan jasa transportasi laut. Perusahaan ini didirikan pada tanggal 25 April 1967 di Jakarta. Pada bulan Mei 1999 jumlah tenaga kerja mencapai 329 orang. PT.Karana Line merupakan salah satu anggota Indonesian National Shipowner Association (INSA) dan Indonesian National Line (INL) yang cukup dikenal di Indonesia. Pada tanggal 21 November 1988 pemerintah mengeluarkan kebijakan yang dikenal dengan Paket Kebijaksanaan November (PAKNOV) 21/1988 dimana dengan adanya kebijakan ini banyak bermunculan perusahaan pelayaran yang tidak memiliki kapal sendiri. Padahal kepemilikan kapal merupakan salah satu persyaratan pendirian perusahaan pelayaran yang cukup berat sebelum adanya PAKNOV 21/1988. Meskipun perusahaan- perusahaan pelayaran tersebut tidak memiliki kapal sendiri, namun dapat mengoperasikan dan mengageni kapal nasional maupun asing, sehingga terjadi persaingan ketat dalam bidang angkutan laut di Indonesia. Krisis ekonomi dan politik yang melanda Indonesia menjelang era pasar bebas telah mendorong PT Karana Line untuk menerapkan strategi yang sesuai dengan kondisi internal maupun eksternal perusahaan. Untuk itu perlu ditelaah 1). Faktor faktor apa saja yang mempengaruhi perkembangan - usaha PT.Karana Line, 2). Strategi apa yang akan digunakan untuk keberhasilan pengembangan usaha PT. Karana Line, 3). Program apa yang perlu dilakukan untuk mewujudkan strategi dalam mengembangkan usaha PT.Karana line, 4). Sistem pelayanan mana yang perlu dioptimalkan, sehingga memberikan keuntungan maksimal....dst
Keyword: strategi bisnis