Papers by Safri Ishmayana
Revista de Chimie, 2021
Zinc oxide nanoparticles have wide applications as catalysts, antimicrobial agents, drug delivery... more Zinc oxide nanoparticles have wide applications as catalysts, antimicrobial agents, drug delivery agents, etc. because of their intrinsic properties. Various methods can be applied to synthesise nanoparticles, one of which is the biosynthesis process. Biosynthesis is more eco-friendly than chemical and physical methods. In the present study, the optimisation of zinc oxide nanoparticle biosynthesis using the yeast Saccharomyces cerevisiae was performed by applying a response surface method called the Box�Behnken design (BBD). Three factors were optimised in the present study, namely the concentration of zinc acetate as the precursor (X1), concentration of the S. cerevisiae fermentation broth (X2), and the incubation time (X3). The mass of zinc oxide nanoparticles (Y) was recorded as the response of the experiment. The product was then characterised by fourier transform infrared spectroscopy (FTIR), X-Ray diffraction (XRD), scanning electron microscopy/energy dispersive spectroscopy (...
Scientific Study & Research: Chemistry & Chemical Engineering, Biotechnology, Food Industry, 2021
The present study determined if metal ions (zinc sulphate, silver nitrate, copper sulphate, manga... more The present study determined if metal ions (zinc sulphate, silver nitrate, copper sulphate, manganese sulphate and ferric chloride) can be used as precursors to prepare nanoparticles using a baker's yeast culture medium. The particles were characterized using Fourier transform infrared (FTIR), scanning electron microscope‒energy-dispersive X-ray (SEM-EDX), transmission electron microscopy (TEM), and X-ray powder diffraction (XRD). The antibacterial activity against Escherichia coli and Streptococcus aureus was also evaluated. Saccharomyces cerevisiae strain A12 culture only synthesized nanoparticles using a silver nitrate solution. FTIR indicated that the protein might play a role in capping the nanoparticles, which formed large aggregates and contained silver, oxygen and a small amount of phosphorus. The nanoparticles were spherical, ranging in size from 9 to 85 nm, crystalline and characterized as Ag2O, however, they demonstrated weak antibacterial activity.
Mixed lactic acid bacteria culture is commonly used in yogurt production. In the present study, t... more Mixed lactic acid bacteria culture is commonly used in yogurt production. In the present study, two lactic acid bacteria (Lactobacillus bulgaricus and Streptococcus thermophillus) was used as starter culture. Calcium carbonate was added to the starter culture to increase the quality of mixed starter culture of L. bulgaricus and S. thermophillus with ratio of 4:1. The present study was directed to investigate the chemical composition of mixed starter culture with and without calcium carbonat addition. Furthermore, the effect of each starter culture on yogurt product chemical composition was also examined. The pH, lactose, soluble protein and acid content was determined as chemical composition parameters. For starter culture without calcium carbonate addition, the yogurt has pH, lactose, soluble protein and acid content of 4.18-4.39, 4.18-4.39% w/v, 2.88-4.36% w/v and 0.82-0.99% w/v, respectively. While for starter culture with calcium carbonate addition, the yogurt product has pH, la...
Fermentation performance of the yeast Saccharomyces cerevisiae is influenced, among others, by gr... more Fermentation performance of the yeast Saccharomyces cerevisiae is influenced, among others, by growth media composition. Media with complex nitrogen source tend to give better fermentation performance. In the present study, we investigate fermentation performance of a bakery yeast strain in normal (20 % w/v glucose) and very high (40 % w/v glucose) gravity media with different nitrogen content. We used yeast extract – peptone (YEP) media with varying concentration of yeast extract, bacteriological peptone, ammonium sulphate, and potassium hydrogen phosphate in the media. For comparison, yeast nitrogen base (YNB) media was used. We found that increasing YEP media component in the media lead to better cell growth, cell health and fermentation performance. The cell appeared to overcome hyperosmotic stress due to high glucose concentration when higher content of YEP used in the media, as indicated by better cell viability. Surprisingly, cell grown in YNB media was observed has the highe...
Al-Kimia, 2017
Purple sweet potato (Ipomoea batatas var. Ayamurasaki) is one of typical sweet tubers which is al... more Purple sweet potato (Ipomoea batatas var. Ayamurasaki) is one of typical sweet tubers which is also commonly well known as Ipomoea blackie due to blackish purple (solid purple) tuber skin and flesh. The sweet potato can be transformed into flour or pasta and used to substitute wheat flour in the production of composite bread. Instead of synthetic chemical compounds, αamylase isolated from the yeast Saccharomycopsis fibuligera can be added to the flour or dough of the composite bread to improve its quality. The purpose of the present study was to investigate the effect of α-amylase addition on the quality of the purple sweet potato flour and pasta composite bread. The observed properties of the bread were crumbs morphology of the bread, volume increment, bread height, texture, and organoleptic test. The results showed that addition of the αamylase to the dough of the composite bread increased the volume increment value from 155.0% to 177.1% and from 335.7% to 342.1% for the sweet potato flour and pasta bread composite, respectively. While height of the bread increased from 4.7 to 5.1 cm and from 6.9 to 7.8 cm after addition of the enzyme for the sweet potato flour and pasta bread composite, respectively. Composite bread with α-amylase addition has softer texture and higher preference. Morphology examination result showed that starch granules in the bread crums with α-amylase treatment were disrupted. Most plausibly, the enzymes degrade the starch granules and produced dextrin which inhibited the cross linking formation between starch and protein, and therefore, the speed of hardening process of the bread can be reduced.
Jurnal MIPA, 2020
Selama proses fermentasi bioetanol, ragi Saccharomyces cerevisiae terpapar berbagai cekaman lingk... more Selama proses fermentasi bioetanol, ragi Saccharomyces cerevisiae terpapar berbagai cekaman lingkungan. Ion logam yang berpotensi untuk meningkatkan kinerja fermentasi dan toleransi sel terhadap cekaman ialah ion logam besi II (Fe2+) yang berperan sebagai kofaktor dalam berbagai proses metabolisme. Tujuan dari penelitian ini adalah mempelajari pengaruh suplementasi ion Fe2+ dalam media fermentasi terhadap kinerja fermentasi, serta toleransi sel ragi terhadap cekaman etanol, oksidatif, asam lemah dan tekanan osmotik. Penelitian diawali dengan melakukan fermentasi glukosa menggunakan S. cerevisiae A12 selama 120 jam dengan pengambilan sampel dengan interval waktu 6 jam untuk 24 jam pertama serta 12 jam untuk sisanya. Masing-masing sampel ditentukan nilai OD600nm, persentase sel hidup, jumlah sel hidup, kadar glukosa, kadar etanol. Pada jam ke 24, sel diuji daya tahannya terhadap cekaman. Hasil penelitian menunjukkan bahwa suplementasi ion logam Fe2+ hanya mampu meningkatkan laju produ...
Poli- γ -asam glutamat (PGA) dan hasil degradasinya aman bagi manusia sehingga dapat dimanfaatkan... more Poli- γ -asam glutamat (PGA) dan hasil degradasinya aman bagi manusia sehingga dapat dimanfaatkan sebagai bahan pengental, pelembab, pelepas berjangka atau sebagai pembawa obat. Meskipun banyak digunakan pada berbagai bidang industri, bahan ini masih diimpor dari luar negeri. Oleh karena itu, perlu dikembangkan suatu proses untuk memproduksi PGA secara efektif dan efisien. Penelitian ini dilakukan untuk menentukan konsentrasi optimum amonium sulfat sebagai sumber nitrogen untuk menghasilkan PGA dalam jumlah yang banyak. Produksi PGA dilakukan dengan fermentasi menggunakan bakteri Bacillus subtilis B112. Analisis yang dilakukan selama proses fermentasi meliputi pengukuran pH, derajat kekeruhan, berat kering sel dan viskositas media. Isolasi PGA dilakukan dengan tahapan sentrifugasi, pengendapan dengan metanol, dialisis dan liofilisasi. PGA yang telah diisolasi kemudian ditentukan berat molekulnya dengan meggunakan SDS-PAGE, sedangkan komposisi asam amino PGA ditentukan dengan menggun...
Satu buah glikosida oleanan berhasil diisolasi dari biji Barringtonia asiatica . Struktur senyaw... more Satu buah glikosida oleanan berhasil diisolasi dari biji Barringtonia asiatica . Struktur senyawa ini ditentukan oleh 1H- dan 13C-NMR satu dan dua dimensi serta oleh perbandingan langsung dengan standar. Senyawa ini menunjukkan aktivitas insektisida yang paling tinggi terhadap Crocidolomia pavonana. Dari penelitian ini diketahui bahwa biji B. asiatica mengandung senyawa insektisida yang paling aktif dengan nilai LC50 sebesar 290 ppm yang potensial untuk aplikasi insektisida. Kata Kunci: Barringtonia asiatica , glikosida oleanan, aktivitas insektisida, Crocidolomia pavonana
International Journal of Scientific & Technology Research, 2016
Three analogues of TMOF, [PP (H-Pro-Pro-OH), PPPPPP (H-Pro-Pro-Pro-Pro-Pro-Pro-OH), and APPPPPP (... more Three analogues of TMOF, [PP (H-Pro-Pro-OH), PPPPPP (H-Pro-Pro-Pro-Pro-Pro-Pro-OH), and APPPPPP (H-Pro-Pro-Pro-Pro-Pro-ProOH)], were successfully synthesised and screened for their insecticidal properties against cabbage cluster caterpillar (Crocidolomia pavonana). All compounds were prepared through Fmoc-based solid-phase peptide synthesis (SPPS) method. The synthesis employed chlorotrityl resin as solid support. A combination of N,N-diisopropylcarbodiimide (DIC) and ethyl 2-cyano-2-(hydroxyimino)acetate (oxyma) was chosen as coupling reagent in the synthesis. The peptide was cleaved by using TFA cocktail. All peptide crudes were purified by using reversed-phase flash chromatography with octadecyl silane (ODS) as stationary phase. All purified peptides were characterized by using TOF-ESMS and their purity was analysed using thin layer chromatography and analytical RP-HPLC. The synthesised TMOF analogues, together with TMOF, were biologically tested towards the (C. pavonana) at 1000...
International Journal of Research in Pharmaceutical Sciences, 2020
Virgin coconut oil (VCO) is a processed coconut product that contains high acid which proved to h... more Virgin coconut oil (VCO) is a processed coconut product that contains high acid which proved to have a health beneficial effect. Fermentation is one of the means to produce VCO. Factors that affect fermentation can be optimized to increase VCO recovery. The objective of the present study was to determine factors that significantly affecting VCO recovery using Plackett-Burman design (PBD), optimization of a fermentation process using Response Surface Methodology-Central Composite Design (RSM-CCD), and determine characteristics of a product. The experiment was performed by growing Neurospora and , isolation, and activity determination of from papaya sap. Nine factors were screened using PBD and the three most significant factors were further optimized using RSM-CCD. The optimum condition was applied to produce VCO and the product was characterized for its properties and fatty acid content. The results indicate that activity, incubation temperature, and pH were the most significant fac...
Al-Kimia, 2016
Exploitation of synthetic antibiotics compounds not only have positive effect for human, but also... more Exploitation of synthetic antibiotics compounds not only have positive effect for human, but also have side effect that can be unfavorable, therefore many researches are being conducted to find natural antibiotics compounds that are safer. Lactic acid bacteria has the abilitytoproduce antibacterial compound when used in fermentation process.For example, Lactobacillus acidophilus produces acidophilin and acidolin. The main purpose of the present study is to investigate antibacterial activity of yogurt fermented with mixed bacterial culture of L. bulgaricus, S. thermophilus and L. acidophilus against Escherichia coli (representing Gram negative bacteria) and Bacillus subtilis (representing Gram positive bacteria). The antibacterial activity of the yogurt at three different time points (5, 7 and 9 hours) were examined. We also investigate the fermentation parameters of the yogurt production. The results of the present study indicate that the crude yogurt extract has antibacterial activity, where the highest activity was observed at 7 hour of incubation, resulting 0.35 and 0.30 cm of clear zone against E. coli and B. subtilis, respectively. It is most likely that the compound is non protein compound.
Jurnal Entomologi Indonesia, 2015
An examination of insect resistance was determined by several steps, i.e. standard sensitivity, r... more An examination of insect resistance was determined by several steps, i.e. standard sensitivity, resistance diagnosis, and determination of resistance level. Each phase was tested with feeding and residue contact methods at glass tube. Resistance ratio (RR) was determined by comparing LC50 value of field population with standard population. Field population of C. pavonana was classified resistant if it had RR 5 4. Biochemistry analysis of resistance was conducted to population of C. pavonana showing resistance to prophenophos insecticide. The activity analysis of acetylcholine esterase (ACHE), esterase, and Glutation Stransferase was done with spectrophotometer method. Insect which are resistant to prophenophos insecticide was tested for its sensitivity to Barringtonia asiatica seed extract. Result indicated that C. pavonana population from Pengalengan showed resistance to prophenophos synthetic insecticide. Using contact test, the highest resistance ratio value was 4.04, while by fe...
Chimica et Natura Acta, 2015
Asam sitrat terdapat melimpah di alam dan dihasilkan sebagai salah satu zat antara pada siklus as... more Asam sitrat terdapat melimpah di alam dan dihasilkan sebagai salah satu zat antara pada siklus asam sitrat saat karbohidrat dioksidasi menjadi karbondioksida. Asam sitrat merupakan penyebab rasa asam pada berbagai buah seperti jeruk, nanas dan pir. Karena kelarutannya yang tinggi, rasanya yang enak dan toksisitasnya yang rendah maka asam sitrat banyak digunakan dalam industri makanan, minuman dan obat-obatan. Salah satu metode yang digunakan untuk produksi asam sitrat adalah dengan metode fermentasi. Aspergilus niger merupakan salah satu mikroorganisme yang dapat digunakan pada proses produksi asam sitrat. Produksi asam sitrat pada penelitian ini dilakukan dengan tahap pemeliharaan A. niger pada media agar miring, aktivasi kultur A. niger dalam inokulum dan produksi asam sitrat dalam media fermentasi yang mengandung 20, 25, 30 dan 35% konsentrasi molase dengan metode biak rendam. Analisis yang dilakukan mencakup perubahan pH, berat kering sel, konsumsi gula pereduksi, serta konsentr...
Chimica et Natura Acta, 2015
Yoghurt merupakan produk susu terfermentasi yang dibuat dengan menambahkan kultur bakteri asam la... more Yoghurt merupakan produk susu terfermentasi yang dibuat dengan menambahkan kultur bakteri asam laktat (BAL) ke dalam susu. Kultur BAL yang ditambahkan dapat berupa kultur bakteri tunggal ataupun campuran. Pada umumnya, kultur campuran yang biasa digunakan untuk membuat yoghurt adalah campuran antara Lactobacilus bulgaricus (Lb) dan Streptococcus thermophilus (St). Namun berdasarkan beberapa penelitian kedua bakteri ini tidak bertahan lama pada saluran pencernaan. Oleh karena itu pada penelitian ini dilakukan penambahan Lactobacillus acidophilus (La) untuk memperbaiki sifat probiotik dari produk yoghurt. Pada pembuatan kultur starter, kultur tunggal bakteri ditumbuhkan pada media susu skim 10%. Kemudian susu sapi hasil pasteurisasi diinokulasi dengan kultur starter dengan perbandingan kultur yang berbeda-beda yaitu 1:1, 1:4 dan 4:1 (Lb:St) untuk kultur dua bakteri serta 1:1:1, 1:4:1 dan 4:1:1 (Lb:St:La) untuk kultur tiga bakteri. Susu yang telah diinokulasi kemudian diinkubasi pada s...
Molekul, 2013
Microbial fuel cell (MFC) merupakan salah satu teknologi sel bahan bakar alternatif yang dapat di... more Microbial fuel cell (MFC) merupakan salah satu teknologi sel bahan bakar alternatif yang dapat diperbarui. MFC memanfaatkan proses oksidasi senyawa kimia oleh biokatalis untuk menghasilkan energi listrik daya rendah. Tujuan dari penelitian ini adalah mengetahui kinerja MFC dengan dan tanpa mediator elektron metilen biru (MB) menggunakan biokatalis Acetobacter aceti dan substrat glukosa agar diperoleh energi listrik. Metode yang dilakukan adalah peremajaan kultur A. aceti, persiapan inokulum, persiapan reaktor MFC, persiapan media MFC dengan substrat glukosa 2% dengan dan tanpa mediator MB, pencuplikan secara periodik, penentuan kurva pertumbuhan, arus, potensial, kerapatan daya, energi, kadar glukosa dan tingkat keasaman (pH). Hasil penelitian menunjukkan bahwa MFC dengan mediator menghasilkan kuat arus sebesar 0,040 mA, potensial 878 mV, kerapatan daya 0,395 mW/cm2, energi maksimum 3,685 kJ, pemanfaatan glukosa 93,02% dan pH akhir 3,33, sedangkan MFC tanpa mediator menghasilkan kua...
Procedia Chemistry, 2015
Microbial fuel cell (MFC) is one of promising fuel cell technologies. MFC utilizes biochemical ac... more Microbial fuel cell (MFC) is one of promising fuel cell technologies. MFC utilizes biochemical activity of microorganism to convert the substrate to produce electricity through metabolism processes. Although the generation of the electricity is still in mW scale, MFCs has a great potential for the future application. The aim of this study was to investigate the performance of MFCs with and without the methylene blue (MB) as an electron mediator utilizing Saccharomyces cerevisiae as biocatalysts and glucose as substrate to generate electricity. Methods performed comprise of the S. cerevisiae yeast culture rejuvenation, preparation of the inoculum, preparation of the MFC reactor, preparation of MFC medium with 2% of glucose with and without MB mediator, periodical sampling, determination of growth curve, measurement of current, potential, calculation of power density, energy, glucose consumption, and production of bioethanol. MFC with mediator generated 5.5×10-5 A of current, 0.886 V of potential, 4.48×10-3 W/m 2 of power density, 4.14×10-3 J of energy, 95.0% of glucose consumption and 0.74% (v/v) of bioethanol produced during the MFC process, while MFC without mediator generated 4.5×10-5 A of current, 0.689 V of potential, 2.12×10-3 W/m 2 of power density, 1.96×10-3 J of maximum energy, 96.3% of glucose consumption and 0.74 % (v/v) of bioethanol produced. Power density yields from both type of MFC are still very low and not differ significantly. From the present study, it can be concluded that MB mediator only effected on potential yield in MFC using the condition applied in this study.
Procedia Chemistry, 2015
Inositol is known to initiate positive effects on yeast fermentation performance, cell growth and... more Inositol is known to initiate positive effects on yeast fermentation performance, cell growth and tolerance against environmental stresses, especially high ethanol concentration. The precise mechanisms by which inositol improves such parameters are yet to be elucidated. The present study was performed to investigate the effect of inositol supplementation on growth, fermentation performance and plasma membrane fluidity during normal gravity fermentation. Yeast cells were grown in a chemically defined fermentation medium with 15% (w/v) glucose, lacking inositol and with 0.1 or 0.4 g/L inositol supplementation. Cell density, cell viability, glucose consumption and ethanol production were monitored for 96 hours. Plasma membrane fluidity was monitored at 24 hours fermentation, representing the respiro-fermentative growth phase, by measuring generalized polarization (GP) of laurdan. The effect of ethanol on membrane fluidity also monitored by measuring GP after exposing cell to 18% (v/v) ethanol. The results of the present experiment indicated that although inositol supplementation did not seem to improve fermentation performance as assessed by glucose consumption and ethanol production, it did improve cell growth leading to higher cell densities. While inositol-supplemented cells had higher growth rates and cell density, they had significantly lower viability, thus the viable cell counts were similar with and without supplementation. There is also evidence that inositol supplementation leads to increased membrane fluidity with significantly lower GP values for yeast cells grown in the inositol supplemented media. However when exposed to high ethanol concentrations, inositol-supplemented yeasts showed a greater GP decrease than those grown without inositol. Thus, interestingly, the nonsupplemented yeasts with lower baseline membrane fluidity seemed to better withstand the fluidizing effects of ethanol. We are in the process of confirming the viability of ethanol-treated cells as well as furthering the investigations on inositol effects on stress tolerance and other physiological parameters.
Azotobacter, yang digunakan sebagai pupuk hayati, menghasilkan eksopolisakarida yang dapat mening... more Azotobacter, yang digunakan sebagai pupuk hayati, menghasilkan eksopolisakarida yang dapat meningkatkan kelarutan logam berat kadmium (Cd) dalam tanah. Tanaman merespon paparan logam berat dengan beberapa cara. Peptida γ-glutamilsistein (γEC) disintesis secara enzimatis oleh tanaman sebagai salah satu respon terhadap paparan logam berat yang berperan sebagai pengkhelat pada proses pengasingan logam berat. Peptida ini disintesis dengan asam amino ujung karboksi yang berbeda, yaitu (γEC)nG, (γEC)nS, (γEC)nβA, (γEC)nE dan (γEC)n. Peptida ini dapat diisolasi dari daun selada (Lactuca sativa L.), namun hanya sedikit informasi yang ada. Penelitian ini bertujuan untuk menyelidiki keberadaan peptida γEC pada tajuk selada dengan menentukan bentuk peptida γEC. Kami juga menentukan komposisi asam aminonya setelah diinokulasi Azotobacter. Peptida diisolasi dengan metode ekstraksi menggunakan asam klorida, diikuti dengan kromatografi filtrasi gel Sephadex G25, pengendapan dengan amonium sulfat d...
Peranan hevein dalam lateks pohon karet telah mendorong penelitian-penelitian tentang keberadaan ... more Peranan hevein dalam lateks pohon karet telah mendorong penelitian-penelitian tentang keberadaan enzim proteolitik yang memiliki peranan dalam pembentukan hevein. Tujuan dari penelitian yang dilakukan adalah untuk mengisolasi dan menentukan karakter protease yang berasal dari BSL lateks karet klon PR-255 dan WR-101. Penelitian dimulai dengan mengambil lateks segar dan sentrifugasi untuk memperoleh tiga fraksi utama. Fraksi bawah yang mengandung partikel lutoid dikumpulkan dan dilakukan proses beku-cair untuk memecah membrane lutoid, larutannya kemudian disentrifugasi dan supernatant dikeringkan dengan menggunakan alat freeze dryer. Pemurnian protease dari BSL dilakukan dengan tahap-tahap pengendapan dengan kejenuhan 0-100% garam ammonium sulfat, kromatografi filtrasi gel dengan Sephadex G25, kromatografi penukar kation CMC CM32 dan kromatografi penukar anion DEAE DE 32. Kedua protease yang berhasil diisolasi memiliki aktivitas optimum pada pH 7,5 dan waktu inkunasi selama 30 menit. ...
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Papers by Safri Ishmayana