Eny Ida Riyanti
Indonesian Center for Agricultural Biotechnology and Genetic Resources Research and Development

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MULTIFUNCTIONAL MUTANTS OF Azospirillum sp. WITH ENHANCED CAPABILITY OF SOLUBILIZING PHOSPHORUS, FIXING NITROGEN AND PRODUCING INDOLE ACETIC ACID Eny Ida Riyanti; Toto Hadiarto; D.N. Susilowati
Indonesian Journal of Agricultural Science Vol 13, No 1 (2012): April 2012
Publisher : Indonesian Agency for Agricultural Research and Development

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21082/ijas.v13n1.2012.p12-17

Abstract

Azospirillum sp. have long been known as biofertilizer for plant growth because of its capability to produce phytohormones and fix nitrogen from the atmosphere. Multifunctional Azospirillum strain Aj Bandung 6.4.1.2 isolated in 2009 from cauliflower (Brassica oleracea) rhizosphere in Lembang, Bandung, West Java, was capable of fixing nitrogen, solubilizing tricalcium-phosphate, and producing phytohormone indole acetic acid (IAA). The study aimed to modify the multifunctions of Azos-pirillum sp. for better capability of fixing N2, solubilizing P, and producing IAA using ethyl methanesulfonate and 1-methyl-3-nitro-1-nitrosoguanidine (EMS) mutagen. The study was conducted at Indonesian Center for Agricultural Biotechnology and Genetic Resources Research and Development (ICABIOGRAD) in 2010. The results showed that this strain was genetically mutagenized using EMS for better performance in solubilizing P, fixing N2 (nitrogenase activity), and producing phytohormone (IAA). The optimum concentration and the length of incubation time for the process have been determined. Nine selected mutants with increasing capability to solubilize P (determined by clear-zone formation on Pikovskaya’s medium) have been characterized for nitrogenase activities and IAA production compared to wild type Aj Bandung 6.4.1.2. The effect of mutagenesis on IAA produc-tion and nitrogenase activities varied among the mutans. Two mutants, AzM 3.7.1.16 and AzM 1.7.2.12, showed superiority in the production of IAA, while two mutants, AzM 1.5.1.14 and AzM 3.7.1.15, were superior in nitrogenase activities. The EMS mutagenesis of Azospirillum sp. showed enhanced dissolving capa-bility of unsoluble phosphate (tricalciumphosphate) and increased IAA production and nitrogenase activity.  
KINETIC EVALUATION OF ETHANOL-TOLERANT THERMOPHILE Geobacillus thermoglucosidasius M10EXG FOR ETHANOL PRODUCTION Eny Ida Riyanti; Peter L. Rogers
Indonesian Journal of Agricultural Science Vol 10, No 1 (2009): April 2009
Publisher : Indonesian Agency for Agricultural Research and Development

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21082/ijas.v10n1.2009.p24-41

Abstract

Thermophiles are challenging to be studied for ethanol production using agricultural waste containing lignocellulosic materials rich in hexose and pentose. These bacteria have many advantages such as utilizing a wide range of substrates, including pentose (C5) and hexose (C6). In ethanol production, it is important to use ethanol tolerant strain capable in converting lignocellulosic hydrolysate. This study was aimed to investigate the growth profile of ethanol-tolerant thermophile Geobacillus thermoglucosidasius M10EXG using a defined growth medium consisted of single carbon glucose (TGTV), xylose (TXTV), and a mixture of glucose and xylose (TGXTV), together with the effect of yeast extract additionto the media. The experiments were conducted at the School of Biotechnology and Biomolecular Sciences of The University of New South Wales, Australia on a shake flask fermentation at 60°C in duplicate experiment. Cultures were sampled every two hours and analised for their kinetic parameters including the maximum specific growth rate (µmax), biomass yield (Yx/s), ethanol and by-product yields (acetate and L-lactate) (Yp/s), and the doubling time (Td). Results showed that this strain was capable of growing on minimal medium containing glucose or xylose as a single carbon source. This strain utilized glucose and xylose simultaneously (co-fermentation), although there was glucose repression of xylose at relatively low glucose concentration (0.5% w/v), particularly when yeast extract (0.2% w/v) was added to the medium. The highest biomass yield was obtained at 0.5 g l-1 on glucose medium; the yield increased when yeast extract was added (at 0.59 g l-1). The highest specific growth rate of 0.25 was obtained in the phase I growth when the strain was grown on a mixture of glucose and xylose (0.5% : 0.5% w/v) medium. Diauxic growth was shown on the mixture of glucose, xylose, and yeast extract. The strain produced low level of ethanol (0.1 g l-1), as well as low level (0.2 g l-1) of by-products (L-lactate and acetate) after 15 hours. The results suggests its potential application for fermenting lignocellulosic agricultural wastes for ethanol production.
EFFECTS OF LATE BLIGHT RESISTANT POTATO CONTAINING RB GENE ON THE SOIL MICROBES, PESTS AND PLANT DISEASES Eny Ida Riyanti; Edy Listanto; Alberta Dinar Ambarwati
Indonesian Journal of Agricultural Science Vol 15, No 2 (2014): October 2014
Publisher : Indonesian Agency for Agricultural Research and Development

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21082/ijas.v15n2.2014.p47-54

Abstract

Late blight caused by Phytophthora infestans is an important disease on potato.  Several potato hybrids have been generated by crossing local varieties (Atlantic and Granola) with Katahdin SP951 which contains late blight resistance gene RB.  Prior to release, these hybrids need to be evaluated for their environ-mental effects on non-target organisms and natural pests and diseases. The objectives of the study were to investigate the effect of LBR potato hybrids on beneficial soil microbes, pests and diseases. The trial was conducted in the confined field trial (CFT) in Lembang, West Java. The parental non-transgenic (NT) clones (Granola, Atlantic and Katahdin) and LBR hybrids (four clones of Atlantic x Katahdin SP951 hybrids; 10 clones of Granola x Katahdin SP951) were planted at a plant spacing of 30 cm x 70 cm. Fungicide applications were used as treat-ments (no spray, five and twenty times sprays). The experi-ment was arranged in a randomized completely block design with three replications. The parameters determined were popula-tions of N2 fixing and P solubilizing bacteria, soil C/N ratio as well as natural pests and diseases. The results showed that the transgenic LBR potato hybrids did not have negative effect on N fixing bacteria. The bacterial populations were around 1010-11 cells g-1 soil before planting, 1012 cells at 1.5 months after planting (MAP) and 108 cells after harvest. For P- solubilizing bacteria, their populations were 1010 cells before planting, 1012 cells at 1.5 MAP and 1011 cells g-1  soil after harvest. The soil C/N ratio of the transgenic plot was not statistically different compared to non-transgenic plot, i.e. 12-15 before planting, 10-11 at 1.5 MAP, and 10 after harvest in non-spray plot. Pests and diseases such as Alternaria solani, Liriomyza, potato tubber moth, aphid and mites on the transgenic and non-transgenic plots were statistically not different. The resistance score for A. solani was 7.2 (parental tansgenic) and 7.6 (parental non-transgenic); for Liriomyza it was 2.07 (parental transgenic) and 2.32 insect per plant (parental non-transgenic), the PTM was 0.63 (parental transgenic) and 0.73 insect per plant (parental non-transgenic), aphid and mites were 0.75 (parental transgenic) and 1.68 insects per plant (parental non-transgenic). The study indicated that LBR potato hybrids did not have any negative impacts on non-target organisms.
Agrobacterium tumefaciens-MEDIATED IN-PLANTA TRANSFORMATION OF INDONESIAN MAIZE USING pIG121Hm-Cs PLASMID CONTAINING nptII AND hpt GENES Edy Listanto; Eny Ida Riyanti; Sustiprijatno Sustiprijatno
Indonesian Journal of Agricultural Science Vol 17, No 2 (2016): October 2016
Publisher : Indonesian Agency for Agricultural Research and Development

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21082/ijas.v17n2.2016.p49-56

Abstract

Maize (Zea mays L.) productivity in Indonesia is challenged to be increased using genetic engineering. Recent advances in Agrobacterium tumefaciens-mediated in-planta transforma-tion makes it possible to transform maize with low cost, and simple method. This study aimed to confirm pIG121Hm-Cs plasmid in A. tumefaciens, and to estimate the efficiency level of  A. tumefaciens-mediated in-planta transformation of Indonesian maize by using pIG121Hm-Cs plasmid containing nptII and hpt genes. A series of studies were conducted including confirmation of gene construct of pIG121Hm-Cs plasmid in A. tumefaciens, transformation of four maize lines through A. tumefaciens-mediated in-planta technique, acclimatization of transformant plants and molecular analysis of selected plants using polymerase chain reaction (PCR). The pIG121Hm-Cs plasmid was confirmed via PCR analysis using specific primers of nptII and hpt genes and resulted 700 bp and 500 bp for fragments of nptII and hpt, respectively. After selection, acclimatization and molecular analysis steps, the efficiency levels of transformation of four maize lines were low, ranging from 3.8% to 12.8%. The level of transformation efficiency of ST-27 line was the highest accounting for 12.8% of 45 planted embryos on selection medium based on PCR analysis using specific primer for nptII gene. Overall, A. tumefaciens-mediated in planta transformation on maize floral pistil in this study proved to be successful and rapid. Therefore, this enhanced transformation method will be beneficial for Indonesian maize genetic engineering.