Charlie Ester de Fretes
Research Center For Deep Sea, National Research And Innovation Agency, Jl. Y. Syaranamual, Ambon, Maluku, 97123, Indonesia

Published : 5 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 5 Documents
Search

Characterization of Streptomyces spp. Producing Indole-3-acetic acid as Biostimulant Agent de Fretes, Charlie Ester; Sembiring, Langkah; Purwestri, Yekti Asih
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 (273.427 KB)

Abstract

Twenty six isolates of Streptomyces spp. obtained from Cyperus rotundus L. rhizosphere were tested forability to produce indole-3-acetic acid (IAA) in yeast malt extract (YM) medium containing 2 mg/mL tryptophan.Screening of the isolates for ability to produce IAA was carried out by adding Salkowski reagent in bacteriaculture and was measured quantitatively by spectrophotometer at λ 530 nm. Thin Layer Chromatography (TLC)method was used to determine IAA. To ensure the IAA production in Streptomyces isolates, gene involved inIAA biosynthesis was detected by amplifying Tryptophan Monooxigenase (iaaM) gene. The study of the effectof tryptophan on the production of IAA was measured at different concentrations of tryptophan (0, 1, 2, 3,4, 5 mg/mL) in the bacterial culture. The result showed that there were two Streptomyces spp. isolates whichcould produce IAA, namely the isolates of Streptomyces sp. MS1 (125.48 μg/mL) and Streptomyces sp. BR27(104.13 μg/mL). The TLC result showed that the compound in both isolates was identifi ed to be IAA. Theamplifi cation results showed that iaaM gene was detected in both isolates. This results indicated that the IAMpathway is predicted involved in the biosynthesis of IAA in the selected isolates. Both of the isolates were ableto produce IAA after 24 h incubation and the highest production was at 120 h incubation with the concentrationof tryptophan was 2 mg/mL dan 1 mg/mL, respectively. Therefore, it is concluded that Streptomyces spp.isolates are able to produce IAA and potentially to be utilized as biostimulat agent.Keywords: Streptomyces spp., indole-3-acetic acid (IAA), indole-3-acetamide (IAM), Tryptophan Monooxigenasegene (iaaM)
Isolasi dan Identifikasi Bakteri Toleran Logam Berat dari Sedimen Mangrove di Pengudang dan Tanjung Uban, Pulau Bintan, Indonesia de Fretes, Charlie Ester; Sutiknowati, Lies Indah; Falahudin, Dede
OLDI (Oseanologi dan Limnologi di Indonesia) Vol 4, No 2 (2019)
Publisher : Indonesian Institute of Sciences

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (902.267 KB) | DOI: 10.14203/oldi.2019.v4i2.244

Abstract

Isolation and Identification of Heavy Metals Tolerant Bacteria from Mangrove Sediment in Pengudang and Tanjung Uban, Bintan Island, Indonesia. Bacterial searches for remediation of heavy metal pollutants continue to be carried out due to the increasing pollution in the ecosystem as a result of industrialization. This research aims to identification bacteria strains that are tolerant of heavy metals from mangrove sediments in the Pengudang and Tanjung Uban, Bintan Island in 2018. Bacterial isolation was carried out by pour plate method and purified using marine agar (MA) medium. Screening of bacterial isolates was carried out by growing isolates on MA medium with the addition of 100 ppm Pb. In addition, the determination of minimum inhibitory concentration (MIC) was performed on the isolates were tolerant to Pb, Cu, and Cd by addition of heavy metals in 50-1000 ppm concentrations. Identification of heavy metal tolerant isolates was carried out by sequencing the 16S rRNA gene. The results of bacterial isolation from mangrove sediments obtained 48 isolates used for testing the ability of heavy metals tolerant. Screening tests showed that PGD1A, PGD5A, PGD22A, PGD1B, PGD9B, PGD5C, PGD6C, TJU1, TJU5, and TJU7 isolates were heavy metal resistant. The results showed that bacterial isolated from mangrove sediments had MIC values of 800-900 ppm for Pb, 100-800 ppm for Cu and 100-200 ppm for Cd. There are 3 isolates that have high resistance to three kinds of heavy metals such as Bacillus oceanisediminis PGD1A, Vibrio alginolyticus PGD5A, and Halobacillus kuroshimensis PGD9B. This indicates that the isolate can be used efficiently for removal of heavy metals from the ecosystem.
Characterization of Streptomyces spp. Producing Indole-3-acetic acid as Biostimulant Agent Charlie Ester de Fretes; Langkah Sembiring; Yekti Asih Purwestri
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 (273.427 KB) | DOI: 10.22146/ijbiotech.7872

Abstract

Twenty six isolates of Streptomyces spp. obtained from Cyperus rotundus L. rhizosphere were tested forability to produce indole-3-acetic acid (IAA) in yeast malt extract (YM) medium containing 2 mg/mL tryptophan.Screening of the isolates for ability to produce IAA was carried out by adding Salkowski reagent in bacteriaculture and was measured quantitatively by spectrophotometer at λ 530 nm. Thin Layer Chromatography (TLC)method was used to determine IAA. To ensure the IAA production in Streptomyces isolates, gene involved inIAA biosynthesis was detected by amplifying Tryptophan Monooxigenase (iaaM) gene. The study of the effectof tryptophan on the production of IAA was measured at different concentrations of tryptophan (0, 1, 2, 3,4, 5 mg/mL) in the bacterial culture. The result showed that there were two Streptomyces spp. isolates whichcould produce IAA, namely the isolates of Streptomyces sp. MS1 (125.48 μg/mL) and Streptomyces sp. BR27(104.13 μg/mL). The TLC result showed that the compound in both isolates was identifi ed to be IAA. Theamplifi cation results showed that iaaM gene was detected in both isolates. This results indicated that the IAMpathway is predicted involved in the biosynthesis of IAA in the selected isolates. Both of the isolates were ableto produce IAA after 24 h incubation and the highest production was at 120 h incubation with the concentrationof tryptophan was 2 mg/mL dan 1 mg/mL, respectively. Therefore, it is concluded that Streptomyces spp.isolates are able to produce IAA and potentially to be utilized as biostimulat agent. Keywords: Streptomyces spp., indole-3-acetic acid (IAA), indole-3-acetamide (IAM), Tryptophan Monooxigenasegene (iaaM)
Plant growth‐promoting activity of endophytic bacteria from sweet sorghum (Sorghum bicolor (L.) Moench) Charlie Ester de Fretes; Donny Widianto; Yekti Asih Purwestri; Tri Rini Nuringtyas
Indonesian Journal of Biotechnology Vol 26, No 4 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijbiotech.64893

Abstract

Application of high levels of chemical fertilizers for optimal growth of sweet sorghum causes environmental degradation. Plant growth‐promoting bacteria have biotechnological importance because they can improve the growth and health of important agronomic plants. This study aimed to isolate, characterize, and identify endophytic bacteria associated with sweet sorghum (cv. KCS105), and also to study the inoculation effects of selected isolates on sorghum growth. In this study, 35 isolates were evaluated for their ability to support plant growth. The results showed that seven isolates were diazotrophic, six were capable of dissolving phosphate, six produced IAA and could detect ACC‐deaminase activity, and three inhibited the growth of pathogenic fungi. Nine isolates exhibiting mechanisms for promoting plant growth from the Alphaproteobacteria (Devosia), Firmicutes (Bacillus, Paenibacillus, Staphylococcus), and Actinobacteria (Microbacterium, Brachybacterium) phyla were identified. In addition, the Paenibacillus sp. BB7, Bacillus sp. PIB1B, and Bacillus sp. PLB1B isolates showed increasing effects on plant growth in greenhouse tests. Endophytic bacterial isolates which display plant growth‐promoting features can potentially be employed as biofertilizer agents. They may also address environmental damage problems resulting from the use of chemical fertilizers and pesticides.
ISOLASI DAN KARAKTERISASI KEMAMPUAN BAKTERI ENDOFIT SORGUM MANIS FS501 SEBAGAI PENDUKUNG PERTUMBUHAN TANAMAN Charlie Ester de Fretes
EKOTONIA: Jurnal Penelitian Biologi, Botani, Zoologi, dan Mikrobiologi Vol 5 No 2 (2020): Ekotonia: Jurnal Penelitian Biologi, Botani, Zoologi dan Mikrobiologi
Publisher : Department of Biology, Faculty of Agriculture, Fisheries and Biology, University of Bangka Belitung

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (342.759 KB) | DOI: 10.33019/ekotonia.v5i2.2107

Abstract

This study aims to isolate endophytic bacteria of sweet sorghum plants and characterize their ability as plant growth promoting. The characters tested in this study were the ability of endophytic bacteria in N fixation, phosphate dissolving, and IAA production to be developed as biological fertilizer agents. Twenty-four isolates were isolated from the roots, stems and shoots of sweet sorghum. The results of bacterial DNA fingerprint screening showed that 11 groups of endophytic bacteria had different fingerprints. Isolates capable of N fixation were grown on LGI media and showed a change in the color of the medium. The nifH gene detection is also carried out to determine endophytic diazotrophic bacteria. Isolate bacteria that can dissolve inorganic phosphate were tested using Pikovskaya media. Testing the ability of isolates to produce IAA was carried out by adding Salkowski's reagent to the bacterial culture and measured quantitatively with a λ 530 nm spectrophotometer. The results showed that two endophytic bacterial isolates proved to be diazotrophic and three isolates were able to dissolve phosphate, while one isolate was able to produce IAA. PA2 isolate showed ability in all the characters tested, namely N fixation, phosphate solvent and IAA producer.