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"ABSTRAKA natural-based nanocomposite film consisting of chitosan, montmorillonite (MMT) and cashew nut shell liquid (CNSL) was synthesized. The nanocomposite was prepared by mixing a suspension of clay particles (filler, MMT) with a solution containing chitosan as the macroscopic polymer matrix. In this study, it was proposed that non-ionic long-chain alkylmolecules with possible interact ions with the amine group of chitosan could be used as a plasticizer. As a natu-ral source for these compounds, an extract of CNSL was used. A series of chitosan/MMT com-posite samples containing two different clay contents and a sample with an additional CNSL were prepared. FTIR spectroscopy of the nanocomposite films indicated that, by addition of CNSL, amide groups of the chitosan are probably less attached and have more space for vibration. CNSL seems to provide intermolecular spaces between the chitosan molecules. Atomic force microscopy (AFM) analysis showed that the composite containedparticles measuring 100 nm or less, which confirmed that the nanocomposite had been successfully produced by this method. Addition of CNSL as plasticizer improved the tensile strength by 10% and the elastic modulus by almost 18%. Cell growth was observed on all the nanocomposite samples studied."

"ABSTRACTGambier (Uncaria gambier) is known to have antioxidant properties, and some studies have attributed it to the presenceof polyphenols such as catechin. The objective of this study is to investigate the potential of various gambiers availablein Indonesian market as a scavenger of reactive freeradicals and evaluate its anti-hyperglycemic activity as α-glucosidase inhibitor. Isolation of catechin was done by extraction method with technical grade of ethyl acetate as solvent. Analysis of catechin in the dried gambier extract was carried out with TLC method. The molecular weight and content of catechin of dried gambier extract was determined by analyzing its mass spectra and spectrophotometer,respectively. The free radical scavenging activity of catechin of the resultant extracts was measured by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) as stable free radical compound. The anti-hyperglycemic activity of catechin of ethyl acetate extracts was analyzed as α-glucosidase inhibitor. The result showed that various gambiers available in themarket are very active as antioxidant, indicated by IC50of catechin of ethyl acetate extracts which were 4.6 to 18.2μg/mL for DPPH inhibition. The IC50 for α-glucosidase inhibition is ranged from 40.45 to 52.43μ g/mL, so they can be classified as anti-diabetic."

"Senyawa kromium banyak digunakan dalam industri modern. Senyawa tersebut banyak dibuang begitu saja ke lingkungan sekitar. Teknologi membrane lebih efisien dan efektif dari pada metode konvensional untuk pengolahan limbah. Tujuan penelitian adalah membuat membran yang dapat digunakan dalam proses pemisahan Cr(VI). Membran dibuat dari kitosan dan silika sekam padi. Variasi kitosan dan silika sekam padi yang digunakan (g) adalah 2:1 (A1), 2:2 (A2), 3:1 (B1), dan 3:2 (B2). Membran dibuat dengan menggunakan teknik inversa fasa. Dari hasil karakterisasi SEM diketahui bahwa membran B2 mempunyai pori yang paling besar yaitu 2,58μm. Hasil karakterisasi FTIR menunjukkan adanya ikatan silang antara kitosan dengan silika sekam padi dengan munculnya pita serapan Si-O pada bilangan gelombang 1122-980/cm. Membran A1 dengan ukuran pori paling kecil mempunyai nilai rejeksi terhadap Cr(VI) paling besar yaitu 70%. Penelitian menunjukkan bahwa membran komposit-silika sekam padi cukup efektif untuk menyerap logam Cr(VI) dengan kapasitas adsorpsi rata-rata adalah 1665.85 mg/g.

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Chromium compounds are widely used in modern industry. Many of these compounds are dumped into the surrounding environment. Membrane technology is more efficient and effective than conventional methods for waste treatment. The research objective is to make a membrane separation proce ss that can be applied to Cr(VI). Membranes are made from chitosan and silica rice husks. Variations of chitosan and silica rice husk used (g) are 2:1 (A1), 2:2 (A2), 3:1 (B1), and 3:2 (B2). The membrane is made by using an inverted phase technique. Results of SEM characterization of membranes show that B2 has the largest pores at 2.58 μ m. The FTIR characterization results indicate the presence of crosslinking between chitosan with silica rice husk with the appearance of Si-O adsorption band at wavelength 1122-980/cm. A1 membrane, with the smallest pore size has the greatest rejection value towards Cr(VI) which is 70%. Research shows that the composite membrane of silica rice husk is effective enough to adsorb metal Cr(VI) with an average adsorption capacity of 1665.85 mg/g. "

"Eritropoietin (EPO) adalah hormon glikoprotein yang terdiri dari 165 asam amino dan memiliki berat molekul sebesar 30.400 Daltons. Sebagian besar kebutuhan EPO didapatkan dari hasil sintesis pada selmamalia Chinese hamster ovary (CHO). Pichia pastoris adalah sejenis khamir yang populer digunakan untuk menggantikan sistem ekspresi pada sel mamalia. P. pastoris dapat menggunakan metanol sebagai satu-satunya sumber energi karbon. Pada studi ini, protein rekombinan EPO (rhEPO) disintesis dengan cara mengekspresikan gen hEPO pada khamir metilotropik P. pastoris strain X33. Studi ini dilakukan untuk mengetahui konsentrasi metanol dan waktuinkubasi yang optimal untuk mensintesis rhEPO. Pada studi ini konsentrasi metanol yang digunakan adalah 0%, 0.5%, 1%, 2.5%, 5%, 10%, dan 20%. Sedangkan waktu inkubasi yang digunakan adalah 0 jam, 24 jam, 48 jam, 72 jam, 96 jam, 120 jam, and 144 jam. Hasil penelitian ini menunjukkan bahwa ekspresi protein yang tertinggi terjadi padakonsentrasi metanol sebesar 2.5% dan waktu inkubasi selama 48 jam.

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AbstractErythropoietin (EPO) is a glycoprotein hormone consists of 165 amino acids and has molecular mass of 30,400 Daltons. The large quantities of these hormone required to satisfy clinical demand are currently met by recombinant expression in mammalian cell, namely chinese hamster ovary (CHO). Pichia pastoris has become popular yeast based proteinproduction systems to substitute mammalian expression systems.P. pastoris is capable to use methanol as sole carbon and energy source. In this study, recombinant human EPO (rhEPO) protein obtained by expressing the hEPO gene in methylotropic yeastP. pastoris, strain X33. The present work was carried out to study the optimal methanol concentration for induction and the incubation time to obtain rhEPO protein. To perform this study, the transformedP. pastoris was induced with various concentrations of methanol (0%, 0.5%, 1%, 2.5%, 5%, 10%, and 20%) and incubation times (0 hours, 24 hours, 48 hours, 72 hours, 96 hours, 120 hours, and 144 hours). The results demonstrate that the highest protein expression level occurred at concentration of 2.5% methanol induction, while the optimal incubation time was at 48 hrs. "

"Diafiltration by means of the ultrafiltration system of probiotic fermented Mung beans (Phaseolus radiatus L.) concentrate has been performed to reduce or eliminate salts and smaller impurities than the nominal cut-off of the membrane of 20,000 nominal weight cut-off (NWCO). These processes have been conducted as an attempt in order to get a probiotic product with organoleptic acceptability, composition, and the optimal total lactic acid bacteria (LAB)counts because the presence of salts will affect on the viabilityof LAB and the cell lysis of LAB and limit its utility in food products. Concentrate of probiotic mung beans was prepared through fermentation of LAB using inoculum of LAB consisting ofLactobacillus bulgaricus and Streptococcus thermophylus(1 : 1) on fermented mung beans extract inoculated by inoculum ofRhizopus ?C1in rice substrates at salt condition. Ultrafiltration and diafiltration modes have been carried out at flow rate of 8.77 Liter/minute, room temperature and the pressure of 5 bar (0 to 79.7 minutes) and 7 bar (0-154.5 minutes) with the ratio of the volume of pure water to the volume of initial feed (number of diavolume, Nd)of 0, 0.25, 0.5, 0.75, 1.0 and 1.25, respectively. The experiment results based on total LAB counts as a probiotic product show that a high Nd can reduce the salt content but increase the total LAB counts. Nd of 1.0 results reduce the salt content which is equal to retentate, permeate, and the optimal total LAB counts. Ultrafiltration and diafiltration modes at the pressure of 7 bar and Nd of 1.0 give a retentate with total solid of 6.1355%, salt of 1.3515% and remove 86.15% of the salt from probiotic fermented mung beans concentrate and total LAB counts of 10.73 log cycles. Meanwhile, the permeate obtained at this condition results in flux value of 10.83 Liter/m 2.hour with contents of total solid of 6.8199%, salt of 1.325% and total LAB counts of 5.49 log cycles."