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 3 Documents
Search
Journal : Indonesian Journal of Biotechnology

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)
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.