Novel Archaeal DNA Polymerase B from Domas Hot Spring West Java

Nine novel archaeal DNA polymerase genes from Domas Hot Spring, West Java have been cloned directly through the natural sample. The characterization of the genes showed that the genes are high homology to the DNA polymerase B of Crenarhaea phyla. Phylogenetic analysis of the amino acid sequences showed that the enzymes are grouped in a new branch from the other Crenarchaea’s DNA Polymerase B. 3D structure analysis of the enzymes show that the structures are closed to the structure of DNA Polymerase B1 from Sulfolobus solfataricus. The nine structures of the enzymes could be grouped into four different structures

The Microwave-assisted Synthesis of Polyethersulfone (PES) as A Matrix in Immobilization of Candida antarctica Lipase B (Cal-B)

Candida antarctica lipase B (Cal-B) has been widely used in the hydrolysis reaction. However, it has some weaknesses, such as: forming of the heavy emulsion during the process, which is difficult to resolve and has no reusability. Therefore, it needs to be immobilized into a suitable matrix. One of the suitable supporting materials is polyethersulfone (PES) and its synthesis becames the objective of this paper. The PES was synthesized via a polycondensation reaction between hydroquinone and 4,4'-dichlorodiphenylsulfonein N-methylpyrrolidone (NMP) as solvent using Microwave Assisted Organic Synthesis (MAOS) method at170 °C for 66 minutes using an irradiation power of 300 watt. The synthesized PES was characterized by FTIR and 1H-NMR (500 MHz, DMSO-d6). Then the PES membrane was prepared from 20 % of the optimized mixtures of PES, PSf (polysulfone), and PEG (polyethylene glycol) dissolved in 80 % NMP.  The Cal-B was immobilized on the PES membrane by mixing it in a shaker at 30 °C and 100 rpm for 24 h using phosphate buffered saline (PBS). The identification of the immobilized Cal-B was done by using FTIR-ATR spectroscopy and SEM micrographs. The results of Lowry assay showed that the ‘Cal-B immobilized’ blended-membrane has a loading capacity of 91 mg/cm2 in a membrane surface area of 17.34 cm2. In this work, the activity of immobilized Cal-B was twice higher than the native enzyme in p-NP (p-Nitrophenolpalmitate) hydrolyzing. The results indicated that the synthesized PES showed a good performance when used as a matrix in the immobilization of Cal-B. Copyright © 2017 BCREC Group. All rights reserved Received: 15th November 2016; Revised: 27th May 2017; Accepted: 24th May 2017; Available online: 23rd October 2017; Published regularly: December 2017 How to Cite: Widhyahrini, K., Handayani, N., Wahyuningrum, D., Nurbaiti, S., Radiman, C.L. (2017). The Microwave-assisted Synthesis of Polyethersulfone (PES) as A Matrix in Immobilization of Candida antarctica Lipase B (Cal-B). Bulletin of Chemical Reaction Engineering & Catalysis, 12(3): 343-350 (doi:10.9767/bcrec.12.3.774.343-350

The Microwave-assisted Synthesis of Polyethersulfone (PES) as A Matrix in Immobilization of Candida antarctica Lipase B (Cal-B)

Candida antarctica lipase B (Cal-B) has been widely used in the hydrolysis reaction. However, it has some weaknesses, such as: forming of the heavy emulsion during the process, which is difficult to resolve and has no reusability. Therefore, it needs to be immobilized into a suitable matrix. One of the suitable supporting materials is polyethersulfone (PES) and its synthesis becames the objective of this paper. The PES was synthesized via a polycondensation reaction between hydroquinone and 4,4'-dichlorodiphenylsulfonein N-methylpyrrolidone (NMP) as solvent using Microwave Assisted Organic Synthesis (MAOS) method at170 °C for 66 minutes using an irradiation power of 300 watt. The synthesized PES was characterized by FTIR and 1H-NMR (500 MHz, DMSO-d6). Then the PES membrane was prepared from 20 % of the optimized mixtures of PES, PSf (polysulfone), and PEG (polyethylene glycol) dissolved in 80 % NMP.  The Cal-B was immobilized on the PES membrane by mixing it in a shaker at 30 °C and 100 rpm for 24 h using phosphate buffered saline (PBS). The identification of the immobilized Cal-B was done by using FTIR-ATR spectroscopy and SEM micrographs. The results of Lowry assay showed that the ‘Cal-B immobilized’ blended-membrane has a loading capacity of 91 mg/cm2 in a membrane surface area of 17.34 cm2. In this work, the activity of immobilized Cal-B was twice higher than the native enzyme in p-NP (p-Nitrophenolpalmitate) hydrolyzing. The results indicated that the synthesized PES showed a good performance when used as a matrix in the immobilization of Cal-B. Copyright © 2017 BCREC Group. All rights reservedReceived: 15th November 2016; Revised: 27th May 2017; Accepted: 24th May 2017; Available online: 23rd October 2017; Published regularly: December 2017How to Cite: Widhyahrini, K., Handayani, N., Wahyuningrum, D., Nurbaiti, S., Radiman, C.L. (2017). The Microwave-assisted Synthesis of Polyethersulfone (PES) as A Matrix in Immobilization of Candida antarctica Lipase B (Cal-B). Bulletin of Chemical Reaction Engineering & Catalysis, 12(3): 343-350 (doi:10.9767/bcrec.12.3.774.343-350)

SINTESIS DAN KARAKTERISASI NUKLEOTIDA BERTANDA [α-32P]ATP

The utilization of nuclear technology in health sector with molecular techniques is increasingly developed today, especially in Indonesia.  One of which is nucleotide compound marked with [α-32P]ATP, this compound has been used as tracer for deoxyribonucleic acid (DNA)/ ribonucleic acid (RNA) in the study of various physiological and pathological processes. [α-32P]ATP is synthesized through several stages of continuous reaction in one reaction vessel. It begins with synthesis of [γ-32P]ATP through an enzymatic reaction, using H332PO4 and ADP, and enzymes  of lactate dehydrogenase, 3-phosphoglycerate phosphokinase and glyceraldehide 3-phospho  dehydrogenase; followed by phosphorilation of 3’AMP with T4 polinucleotide kinase enzyme to produce 3’-[5’-32P]ATP. The result is hydrolyzed with nuclease P1 enzyme to produce [5’-32P]AMP. The unreacted [γ-32P] is degraded by the addition of hexokinase enzyme and glucose. At the final stage of the reaction, the [5’-32P]AMP is  phosphorilated using phosphoenol-piruvat, piruvat kinase, and myokinase to produce [α-32P]ATP. The test results show that the every stage of reaction is characterized using TLC method, PEI cellulose paper as stationary phase and KH3PO4 0,5 M pH 3,5 as mobile phase. At the end of reaction, the yield of [α-32P]ATP reaches 71,7%, at Rf = 0,2

PENGARUH KARAKTERISTIK PEKERJAAN TERHADAP KEPUASAN KERJA KARYAWAN PADA PT. KERETA API (PERSERO)

Santi Nurbaiti, Pengaruh Karakteristik Pekerjaan Terhadap Kepuasan Kerja Karyawan Pada PT. Kereta Api (Persero) (Studi Pada Karyawan PT. KA Daerah Operasi 2 Bandung), di bawah bimbingan Dr. H. Edi Suryadi, M.Si. dan Askolani, SE, MM. Masalah yang dikaji dalam penelitian ini adalah mengenai kepuasan kerja karyawan pada PT. Kereta Api (Persero). Rendahnya kepuasan kerja karyawan merupakan masalah internal organisasi, namun akibatnya sampai pada lingkungan eksternal organisasi, dalam hal ini konsumen. Bagaimana mungkin konsumen dapat merasa puas terhadap pelayanan jika karyawan melakukan aktivitasnya dalam kondisi yang tidak puas. Sehubungan dengan hal itu, PT. KA pada tahun ini terindikasi mengalami kondisi yang tidak baik dan jika dibiarkan akan mengancam eksistensi organisasi. Objek dalam penelitian ini adalah variabel bebas (X) yaitu karakteristik pekerjaan dan variabel terikat (Y) yaitu kepuasan kerja karyawan. Metode yang digunakan dalam penelitian ini adalah descriptive survey dan explanatory survey. Teknik analisa data yang digunakan adalah teknik regresi linier sederhana yang menggunakan koefisien determinasi (r square). Hasil penelitian menunjukkan bahwa karakteristik pekerjaan berada pada kriteria tinggi, dalam arti lain karakteristik pekerjaan pada PT. KA Daop 2 Bandung menurut persepsi karyawan sudah dilaksanakan dengan baik. Kepuasan kerja karyawan juga menunjukkan kriteria tinggi, dalam arti lain karyawan Daop 2 Bandung sudah merasa puas. Besarnya pengaruh karakteristik pekerjaan (variabel X) terhadap kepuasan kerja karyawan (variabel Y) adalah sebesar 0,453 atau 45,30%. Dari hasil penelitian tersebut dapat diketahui bahwa kepuasan kerja karyawan sebesar 45,30% dipengaruhi oleh karakteristik pekerjaan dan sisanya 54,70% dipengaruhi oleh faktor lain

Heterologous Expression of Gene Encoded Thermostable Lipase and Lipolytic Activity

Three lipase genes namely LK2, LK3 and LK5 were successfully sub-cloned into expression vector pET30a. The recombinant vectors were heterologically expressed into Escherichia coli BL21 (DE3) by 1 mM IPTG induced at 37 °C. The protein with the size of 32, 31 and 28 kDa with correspond to LK2, LK3 and LK5 clones were over expressed following SDS-PAGE analysis. Further analysis to quantity the level of expression showed that the protein were over expressed at around 30, 44 and 21 % of the total protein for LK2, LK3 and LK5 respectively. The lipolytic activity of the proteins by using lauric acid (C12) as substrate at 50°C, appeared that LK2 showed the highest activity among the other (1.49U/mg) followed by LK5 (1,10U/mg) and the lowest activity is LK3 (0.94U/mg)

The Role of Electrostatic Interactions on Klentaq1 Insight for Domain Separation

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