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The Effect of Rock Phosphate and Level of Inoculums on The Survivability of Aspergillus niger and Its Solubilization Ability When Pelleted With Rock Phosphate Yudi Sastro; Donny Widianto; Irfan D Prijambada
Jurnal Ilmu Tanah dan Lingkungan Vol 7 No 2 (2005): Jurnal Ilmu Tanah dan Lingkungan
Publisher : Departemen Ilmu Tanah dan Sumberdaya Lahan, Fakultas Pertanian, IPB University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (329.996 KB) | DOI: 10.29244/jitl.7.2.77-80

Abstract

The study is intended to examine the survival of Aspergillus niger and its phosphate solubilizing ability when pelletedwith rock phosphate. An A. niger YD 17 obtainedfrom the Laboratory of Microbiology. Faculty of Agriculture, Gadjah MadaUniversity was used. The pellet was made by mixing rock phosphate (80%) with organic matter (J 3. 9% waste of tapioca. 6% rice bran, and 1% starch) and spore of A. niger. The experimental design was the Complete Randomized Design 5x4 with 3 replicatiOns. The first factor was sources of rock phosphate (Christmas Island. Jordan, China, Ciamis, and Madura). The secondfactor was the number ofinoculums i.e. control without inoculums, 107 • J(t and J(t cfu.g·'. The colony of A. niger that formed at medium of potatoes dextrose agar (PDA) and the amount of soluble phosphorus in the Pikovskaya liquid medium were parameters. Experimental results indicated that sources of rock phosphate and the number of inoculums itif1uence the A. niger survivability and its phosphorus solubilizing ability. Rock phosphate from Ciamis gave the best support for fungus survival and rock phosphate from Christmas Island was the best substrate for phosphate solubilization. The highest soluble phosphate was achieved by ul inoculums.
A Single Base Substitution Adjacent to the Stop Codon in the downstream of the SMP3 gene Affects its Post-trancriptional process in Saccharomyces cerevisiae Donny Widianto; Yukio Mukai; Kenji Irie; Hiroyuki Araki; Yasuji Oshima
Indonesian Journal of Biotechnology Vol 12, No 2 (2007)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (281.29 KB) | DOI: 10.22146/ijbiotech.7774

Abstract

The smp3-1 mutant allele confers increased holding stability of heterologous plasmid, pSR1, and a temperature-sensitive growth defect which is remediable by the addition of 1 M sorbitol as the osmotic stabilizer. The smp3-1 allele contains two base substitutions; one is in the open reading frame and changed the 490th CAT (encoding Histidine) to TAT (tyrosine), and the other one is an A for G substitution, at 2 bp downstream from termination codon. These base substitutions were separated each other by recombination at a BstNI site located between these two substitutions. The base substitution in the 3'' untranslated region was found to be lethal and the defect was unremediable by the osmotic stabilizer, while that in the open reading frame has no appreciable effect to the cell. Thus, both the base substitutions join together confer the smp3-1 mutant phenotype. The smp3-1 mutant cells cultivated at 37 OC in nutrient medium containing 1 M sorbitol showed similar smp3 transcription as in the wild type. These facts suggest that smp3-1 mutation has a defect in its post-transcriptional process.
Ethanol Production by Fermentation of Various Sweet-Stalk Sorghum Juices Using Various Yeast Strains Donny Widianto; Akbar Arofatullah; Triwibowo Yuwono; Irfan Dwidya Prijambada
Indonesian Journal of Biotechnology Vol 15, No 2 (2010)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (308.188 KB) | DOI: 10.22146/ijbiotech.7824

Abstract

The ethanol production by fermentation of sweet-stalk sorghum juice is affected by the juice composition and the capability of the yeast strain to ferment it. Eight yeast strains were tested on their growth and ethanol fermentation abilities in sweet-stalk sorghum juices extracted from three cultivars of sweet sorghum. The best specific growth rate of the yeast strains grown aerobically in the yeast extract peptone dextrose (YEPD) broth and the sweet-stalk sorghum juices of KCS105, FS501, and FS902 cultivars, were achieved by OUT7903, OUT7913, OUT7903, and OUT7027 yeast strains, respectively. However, the best specific CO2 evolution rate of the yeast strain during fermentation of the juices was achieved by OUT7027 yeast strains. The highest ethanol concentration, ethanol yield, and sugar conversion efficiency (SCE) were obtained by strain OUT7921 when it was employed to ferment sweet-stem sorghum juice of FS902 cultivar. It was also observed that the juice extracted from sweet-stalk sorghum of FS902 cultivar is the most suitable medium for all yeast strains to achieve their best fermentation abilities. Thus, it is likely that the growth and ethanol production ability of a yeast strain in sweet-stalk sorghum juice depend on the physiological responses of the yeasts to nutrientcomposition of the sorghum juice and the sorghum cultivar from which the juice was extracted.Key words : Sweet-stalk sorghum juice, ethanol, fermentation, yeast
Legume Nodulating Bacterium, Achromobacter xylosoxidans Found in Tropical Shrub Agroecosystem, Sumatera, Indonesia Sri Wedhastri; Dinar Mindrati Fardhani; Siti Kabirun; Jaka Widada; Donny Widianto; Rusdi Evizal; Irfan Dwidya Prijambada
Indonesian Journal of Biotechnology Vol 18, No 2 (2013)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (183.716 KB) | DOI: 10.22146/ijbiotech.7879

Abstract

Legume nodulating bacteria (LNB), known also as rhizobia, are soil bacteria, which are able to form rootnodules and fi x nitrogen in the leguminous plants. The LNB availability in the soil depends on the type ofagroecosystem, where plant grows. In this study, we isolated LNB from the shrub agroecosystem in Sumatera,Indonesia, and obtained four selected bacterial strains. Among them, the isolate UGM48a formed root nodulein Macroptilium atropurpureum and showed highest number of nitrogenase activity. UGM48a also contains nifHand nodA genes. An analysis of the PCR-amplifi ed 16S rDNA and BLASTn analysis showed that UGM48adisplayed 96% similarity with Achromobacter xylosoxidans. In addition, UGM48a were successfully nodulatedGlycine max (L.) merr var. wilis. This is the fi rst report detecting A. xylosoxidans as nodule-forming species forGlycine max possesing the positive copy of nodA gene. Keywords : Legume Nodulating Bacteria, shrub agroecosystem, Achromobacter xylosoxidans, nodA, Glycine max
Ethanol Fermentation on Mixed Sugars Using Mixed Culture of Two Yeast Strains J. Jasman; Irfan Dwidya Prijambada; Chusnul Hidayat; Donny Widianto
Indonesian Journal of Biotechnology Vol 18, No 2 (2013)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (162.484 KB) | DOI: 10.22146/ijbiotech.7880

Abstract

The objective of this study was to evaluate the use of mixed cultures of the recommended yeast strainsfrom a previous study on ethanol fermentation using a substrate mixture consisting of sucrose, glucose, andfructose. There were three mixed (combination) cultures namely OUT7096/OUT7913, OUT7096/OUT7921,and OUT7913/OUT7921. The fermentation medium contained sugar mixture consisting of glucose, fructose,and sucrose with a composition generally close to the composition of sugars in sweet sorghum juice. Overall,fermentation is carried out in two stages. First fermentation was performed using the three mixed culturesto determine the best combination based on the concentration of ethanol produced and the concentration ofresidual sugar. Second fermentation was conducted using the best mixed culture obtained from the fi rst stage.This second stage was intended to describe the pattern of the changes in the concentration of ethanol, sugarsand biomass during the fermentation progresses and to determine some kinetic parameters namely ethanolyield (Yp/s), growth yield (Yx/s) and specifi c growth rate (μ). The results of the fi rst fermentation showed thatthe best mixed culture was OUT7913/OUT7921 and the subsequent fermentation using this culture providethe highest ethanol yield (Yp/s) = 0.47 g.g-1 that was reached at 53rd hour, growth yield (Yx/s) = 0.425 g.g-1, andμ = 0.12 hour-1.Keywords : fermentation, ethanol, mixed culture, mixed sugar
Sekresi Asam-asam Organik oleh Aspergillus niger YD 17 yang Ditumbuhkan dengan Batuan Fosfat Yudi Sastro; Donny Widianto; Dja'far Shiddieq
Biota : Jurnal Ilmiah Ilmu-Ilmu Hayati Vol 11, No 3 (2006): October 2006
Publisher : Universitas Atma Jaya Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24002/biota.v11i3.2544

Abstract

Information on ability of Aspergillus niger to secrete organic acid is important in using A. niger as phosphate rock-solubilizing microorganism. This research was aimed to examine the ability of A. niger YD 17 secreting organic acid when it was grown with phosphate rock. An A. niger YD 17 was obtained from Laboratory of Microbiology, Faculty of Agriculture, GMU. The phosphate rock used was Christmas Island phosphate rock. Organic materials consisted of tapioca waste industry, rice bran, and starch. The study was conducted in Pikovskaya liquid medium and soils that were taken from Jasinga, Banten, West Java (ultisol) and Karang Jati, Ungaran, Central Java (inceptisol). The type and level of organic acid production were determined using high performance liquid chromatography (HPLC). The results indicated that A. niger YD 17 was able to secrete organic acid when it was grown with phosphate rock. The level of organic acid in the Pikovskaya liquid medium reached 255.7 g.ml-1, whereas in the soil reached 2992.5 g.g-1. Malate dominated organic acid in the Pikovskaya liquid medium, while in the soils dominated by oxalate. The type and level of organic acid secreted by A. niger YD 17 were influenced by carbon and phosphorus sources, concentration of inoculums, and characteristic of the soils.
Pengaruh Bahan Organik dan Suhu Pengeringan terhadap Ketahanan Hidup Aspergillus niger dalam Pupuk Pelet Bio-fosfat Yudi Sastro; Donny Widianto; Irfan D. Prijambada
Biota : Jurnal Ilmiah Ilmu-Ilmu Hayati Vol 12, No 2 (2007): June 2007
Publisher : Universitas Atma Jaya Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24002/biota.v12i2.2667

Abstract

This research was aimed to investigate the effect of organic matter and drying temperature on Aspergillus niger survivability in the rock phosphate pellet fertilizer namely bio-phosphate. The research was arranged by a completely randomized design 3x3x6. Addition of the mixing of tapioca waste, rice bran, and starch (BOC) and the humic substance (BH) in the bio-phosphate, and its drying temperature (SP) were the treatments. Aspergillus niger inoculums survivability in the bio-phosphate was determined using plating methods. The result showed that the addition of BOC decreased amount of A. niger in the bio-phosphate up to 28.0%, while the BH increased the amount of A. niger up to 24.4%. The ideal drying temperature of bio-phosphate pellet fertilizer was 600C.
Pengaruh Campuran Onggok, Sekam, Pati dan Bahan Humat terhadap Pertumbuhan Aspergillus niger dan Kemampuannya dalam Melarutkan Fosfat Yudi Sastro; Donny Widianto; Irfan D. Prijambada
Majalah Ilmiah Biologi BIOSFERA: A Scientific Journal Vol 23, No 3 (2006)
Publisher : Fakultas Biologi | Universitas Jenderal Soedirman

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20884/1.mib.2006.23.3.173

Abstract

The aims of this study were to investigate the effects of the mixture of tapioca waste, rice bran, starch (BOC), and humic substance (BH) on Aspergillus niger growth and its phosphate solubilizing capability. The experiment was conducted in Erlenmeyer flask containing 200 ml Pikovskaya liquid media and incubated on shaker with 100 rotaries per minute for nine days.  The Christmas Island phosphate rock was used as phosphate source.  Aspergillus niger YD 17 was taken from the Laboratory of Microbiology, Faculty of Agriculture, Gadjah Mada University. The experiment was arranged using factorial completely randomized design with three-replications (3x4x3). The level of BOC (i.e. 0, 2, and 4 g.l-1 media)   and BH   (i.e. 0, 1, 2, and 3 ml.l-1) were applied as experimental factors. Dry weight of mycelia and the soluble phosphate in media were parameters of Aspergillus niger growth. The results showed that BOC and BH increased the Aspergillus niger growth and its phosphate solubilizing capability (P£0.05). Four-gram of BOC and 3 ml of BH per litter of media were the best level for Aspergillus niger growth, while 4 g of BOC and 2 ml of BH was the best level for phosphorus solubilization capability.
Positivism Theory in the Context of Modern Legal Thought Donny Widianto; Zainal Arifin Hoesein
International Journal of Law and Society Vol. 1 No. 4 (2024): International Journal of Law and Society
Publisher : Asosiasi Penelitian dan Pengajar Ilmu Hukum Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.62951/ijls.v1i4.204

Abstract

The theory of legal positivism plays a crucial role in the development of modern legal thought by emphasizing the importance of written and systematic norms in law enforcement. This approach is based on the assumption that the law is the product of regulations made by state institutions, as stipulated in various laws, including the 1945 Constitution, the Criminal Code (KUHP), and Law Number 12 of 2011 concerning the Establishment of Laws and Regulations. The methodology used in this study is qualitative analysis through literature studies and interviews with legal experts to explore the understanding of the application of positivism theory in legal practice in Indonesia. The results show that although positivism provides a strong framework for legal analysis and supports legal certainty, there are still significant challenges related to the application of the values of justice and morality in the legal system. This study concludes that to achieve social justice, there needs to be an integration between positivism and moral principles in modern legal practice.