KARAKTERISASI ISOLAT Streptomyces spp. PENGHASIL INDOLE-3-ACETIC ACID SEBAGAI AGEN BIOSTIMULAN

• Main Authors: , Charlie Ester de Fretes, , Dr. Yekti Asih Purwestri, S.Si., M.Si.
• Format: Theses and Dissertations NonPeerReviewed
• Published: [Yogyakarta] : Universitas Gadjah Mada 2013
• Subjects: ETD
• Online Access: https://repository.ugm.ac.id/126321/; http://etd.ugm.ac.id/index.php?mod=penelitian_detail&sub=PenelitianDetail&act=view&typ=html&buku_id=66541
• Institution: Universitas Gadjah Mada

Twenty six isolates of Streptomyces spp. obtained from Cyperus rotundus L. was tested for ability to produce indole-3-acetic acid (IAA) in yeast malt extract (YM) medium with 2 mg/mL tryptophan. Screening of the isolate for ability to produce IAA was done qualitatively by added Salkowski reagent in bacteria culture and using Thin Layer Chromatography (TLC) method but quantitatively was determine by spectrophotometer at λ 530 nm. To ensure the IAA production in Streptomyces isolates, gene involved in IAA biosynthesis was detected by amplifying Tryptophan Monooxigenase (iaaM) gene with PCR method. The study of the effect of tryptophan on the production of IAA was at different concentration of tryptophan (0, 1, 2, 3, 4, 5 mg/mL) in the bacterial culture. The result showed that there were two Streptomyces spp. isolates which could 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 identified to be IAA. The amplification results showed that iaaM gene was detected in both isolates. This results indicated that the IAM pathway is involved in the biosynthesis of IAA in the isolates. Both of the isolates were able to produce IAA after 24 h incubation and the highest production was at 120 h incubation with the concentration of tryptophan was 2 mg/mL dan 1 mg/mL, respectively. Therefore, it can be showed that Streptomyces spp. isolates are able to produce IAA and potentially to be utilized as biostimulat agent