DWI NINGSIH SUSILOWATI
Balai Besar Penelitian dan Pengembangan Bioteknologi dan Sumberdaya Genetik Pertanian, Jl. Tentara Pelajar 3A, Bogor 16111
Articles
6
Documents
Characterization of Lipopolysaccharides of Bradyrhizobium japonicum KDR 15 Heavy Metal Tolerant

HAYATI Journal of Biosciences Vol 13, No 3 (2006): September 2006
Publisher : Bogor Agricultural University, Indonesia

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Abstract

The lipopolysaccharide (LPS) of Bradyrhizobium japonicum KDR 15 heavy metal tolerant strain was isolated by miniphenol-water extraction and yielded LPS in phenol and water phase. The LPS KDR 15 was further characterized by sodium dodecyl sulfate-polyacrilamide gel electrophoresis (SDS PAGE) and showed many bands distributed from an area of high until low molecular weight (LPS IA, IB, and II). Composition analysis of the LPS had been done after acetic acid 1% hydrolysis. The polysaccharide portion consist of glucose, sucrose, galactose, mannose, xylose, arabinose, rhamnose, ribose, glucosamine, and 3-deoksi-D-manno-oktulosonat (KDO). Lipid A portion consisted of C16:0 and C18:1. The LPS also contained 0.02% of protein and 1.7% of phosphate. The presence of functional groups that shows negative charge densities such as phosphate and carboxyl within LPS KDR 15 assumed to be a potentially binding sites for accumulating heavy metals. Key words: Bradyrhizobium japonicum, heavy metal tolerant, lipopolysaccharides

SPECIES AND FUNCTIONAL DIVERSITY OF RHIZOBACTERIA OF RICE PLANT IN THE COASTAL SOILS OF INDONESIA

Indonesian Journal of Agricultural Science Vol 16, No 1 (2015): April 2015
Publisher : Indonesian Center for Agricultural Library Technology Dissemination - IAARD

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Abstract

Rhizobacteria are important components of soil and directly or indirectly influence the soils quality and plant growth for maintaining adequate plant nutrition and reducing the negative environmental effects of fertilizers. Applying high dose of chemical fertilizers in most of rice fields in the coastal areas could reduce the quality of the soil in the long time. There are few studies addressed to verify the species and functional diversity of cultivable rhizobacteria associated with rice plant in the coastal soils. The objective of the study was to verify the species and functional diversity of rhizobacteria isolated from the coastal soils of two rice production areas of Subang and Indramayu, West Java. Special focus was given to verify phosphate solubilization, nitrogen fixation, IAA and cellulase production of the selected 78 strains of rice rhizobacteria isolated from the coastal paddy field, as well as taxonomical analyses based on 16S rRNA. The results showed that among 78 bacterial isolates from the coastal paddy field, mostly were belonging to the Firmicutes, most of them affiliated with genera Bacillus, 75 strains produced IAA, 32 strains fixed nitrogen, 37 strains solubilized phosphate and 33 strains produced cellulase. Several strains of the rhizobacteria were capable of producing plant growth promoting substances (PGPR), alone or in combination, such as IAA, fixing nitrogen,  solubilizing phosphate, and producing cellulase. Taking all of these diverse PGPR characteristics into account, it is clear that the 78 identified isolates have great potential for improving saline soils of the coastal paddy fields in Indonesia.

Identifikasi Entomopatogen Bakteri Merah pada Wereng Batang Coklat (Nilaparvata lugens Stål.)

Jurnal AgroBiogen Vol 7, No 2 (2011): Oktober
Publisher : Balai Besar Penelitian dan Pengembangan Bioteknologi dan Sumber Daya Genetik Pertanian

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Abstract

Indentification of Entomopathogenic Red Bacterial fromBrown Planthopper (Nilaparvata lugens Stål.). Tri P.Priyatno, Yohana A. Dahliani, Yadi Suryadi, I MadeSamudra, Dwi N. Susilowati, Iman Rusmana, Baskoro S.Wibowo, and Cahyadi Irwan. Red bacteria isolated frombrown planthopper (BPH) has been proven pathogenicagainst BPH and others insects. Application of 106 to 107cells/ml of red bacteria caused 65.6-78.2% mortality of BPH.The 50% effective concentration (EC50) and lethal time of redbacteria against BPH is 2.8 x 105 cells/ml and 6.8 days,respectively. Based on phenotypic characters tested on GNMicroPlateTM Biolog kit and 16S rRNA sequneces analysis,red bacteria was identified as Serratia marcescens with 99%similarity. Red pigmen produced by S. marcescens strainBPH is secondary metabolite determined as prodigiosinshowing bactericidal activities against Xanthomonas oryzaepv. oryzae. We concluded that S. marcescens did not onlypotent as biocontrol agent to BPH, but also it can be used tocontrol plant pathogenic bacteria.

Isolasi dan Karakterisasi Aktinomisetes Penghasil Antibakteri Enteropatogen Escherichia coli K1.1, Pseudomonas pseudomallei 02 05, dan Listeria monocytogenes 5407

Jurnal AgroBiogen Vol 3, No 1 (2007): April
Publisher : Balai Besar Penelitian dan Pengembangan Bioteknologi dan Sumber Daya Genetik Pertanian

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Abstract

Isolation and Characterization of Actinomycetes ProducingAntibacterial Compound into EnteropatogenikEscherichia coli K1.1, Pseudomonas pseudomallei 02 05and Listeria monocytogenes 5407. Dwi N. Susilowati,Ratih D. Hastuti, and Erny Yuniarti. The resistance ofbacterial pathogens to some antibacterial agents and sideeffects of the antibacterial usage demanded discovery ofnew effective, safe, and active antibacterial compounds.Some pathogenic bacteria, such as enteropathogen Escherichiacoli (EPEC) that cause diarrhoea on children andinfants, Pseudomonas pseudomallei that cause melioidosison human and animal, and Listeria monocytogenes thatcause listeriosis on newly born babies mortality and death ofpregnant woman. Actinomycetes is the largest bacterialgroup that produce antibiotics. More than 10,000 antibacterialcompounds had been discovered, two-third ofthem were produced by this bacterial group. A study wasdone to isolate and characterize Actinomycetes producingantibacterial compounds effective against EPEC K1.1 and P.pseudomallei 02 05. Soil samples were taken from 39locations in Indonesia and 115 actinomycetes isolates wereobtained. Two of the isolates, i.e., isolate A3.5 that waseffective against P. pseudomallei 02 05 and isolate F6.1 thatwas effective against EPEC K1.1 evaluated further. Theisolate A3.5 had an optimum time 72 hours to produce antibacterialcompound, while F6.1 took 96 hours. The antibacterialcompounds produced by both isolates were dissolvein the a 70% ethyl acetate solution, but not in a 40oCwarm methanol solution because it is very dissolved. Theantibacterial compound extracted from the isolate A3.5 hada similar effectiveness to antibiotics bacithracyn 10 unit andneomycin 30 g. On the other hand, the antibacterialcompound extracted from isolate F6.1 had a similar effectivenessto antibiotics colistin 10 g and doxyciclin 30 g.Further identification of the isolates suggested that both ofthem belongs to the genera Streptomyces.

Analysis of Tea Rhizosphere Bacterial Community at the Seedling Stage Using Terminal Restriction Fragment Length Polymorphism (TRFLP) Techniques

Jurnal Penelitian Teh dan Kina Vol 19, No 2 (2016)
Publisher : Research Institute for Tea and Cinchona

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Abstract

Bio-imunizer contains an active compound of  Chryseobacterium sp. and Bacillus sp. has been developed by PPTK Gambung. This formula has positive effect on the growth of tea plants also potentially increasing resistance of the plant. The purpose of this study was to determine the effects of bacteria in Bio-imunizer to the rhizosphere bacterial communities as well as the consistency of its existence after application on tea plants at the nursery stage. The technique used in this research is Terminal Restriction Fragment Length Polymorphism based on metagenomic and culture dependent approaches. The value of relative abundance, Shannon diversity index, Pielous evenness index, and Simpson dominance index were calculated. Based on the T-RF profiles of rhizosphere bacterial communities show that Chryseobacterium sp. and Bacillus sp. which is the active compound of  Bio-imunizer consistently found in the tea plant rhizosphere. Application of Bio-imunizer can increase the diversity of rhizosphere bacterial community without affecting the communities that already exist.

Potency of tea plant indigenous microbe on plant growth and to against blister blight disease (Exobasidium vexans Massee)

Jurnal Penelitian Teh dan Kina Vol 19, No 1 (2016)
Publisher : Research Institute for Tea and Cinchona

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Abstract

The chemical control method of blister blight (Exobasidium vexans Massee) on tea could inflict various negative impacts. In order to obtain an environmentally sound control method of blister blight disease, a nursery trial has been conducted to know the effectiveness of bacterial combinations. The trial was carried out at Gambung experimental garden, with seven treatments and four replications. The indigenous microbial codes are Azoto II-1, Endo-5 and Endo-76. The treatments tested comprised: control (without bacteria),  Azoto II-1 25% + Endo-5 75%; Azoto II-1 50% + Endo-5 50%; Azoto II-1 75% + Endo-5 25%;  Azoto II-1 25% + Endo-76 75%; Azoto II-1 50% + Endo-76 50%; and Azoto II-1 75% + Endo-76 25%. All of the treatments was applied as a soil drench, 50 ml/plant with bacterial concentration at 0,5%. The parameter observed was blister blight disease intensity, plant heights, stem diameter, leaves number, root length, and root volume. The results showed that the combination of Azoto II-1 75% + Endo-5 25% could suppress the intensity of blister blight disease with disease intensity 1.27%. The treatments also affected plant heights, stem diameter, leaves number, root length, and root volume, 15.32 cm; 3.38 cm; 8.05 cm; 18.25 cm and 2.37 cm, respectively.