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Journal : Indonesian Journal of Biotechnology

Production of Poly-α-hydroxybutyrate (PHB) from Sago Starch by The Native Isolate Bacillus megaterium PSA10 Nur Arfa Yanti; Langkah Sembiring; Sebastian Margino
Indonesian Journal of Biotechnology Vol 14, No 1 (2009)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (340.322 KB) | DOI: 10.22146/ijbiotech.7804

Abstract

A new bacterial strain that produces amylase and poly-a-hidroxybutyrate (PHB) using sago starch as carbon source was characterized and identified to be member of the Bacillus megaterium group based on phenotypic characteristics  and 16S rDNA gene sequences. Amylase activity was determined spectrophotometrically on the basis of substrate concentration reduction. PHB production was quantified with UV spectrophotometer. The polymer produced by B. megaterium PSA10 was identified by  Fourier Transform Infrared spectroscopy (FTIR). The result of the study showed that the amylase specific activity B. megaterium PSA10 was 593,61 DUN/mg protein and PHB production from sago starch was 52,28 % of cell dry weight (CDW). FTIR analysis of the polymer indicated that the strain B.megaterium PSA10 was a potent PHB producer.
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)
A Study on Production of Poly-β-Hydroxybutyrate Bioplastic from Sago Starch by Indigenous Amylolytic Bacteria Nur Arfa Yanti; Langkah Sembiring; Sebastian Margino; Nurhayani H. Muhiddin
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 (205.882 KB) | DOI: 10.22146/ijbiotech.7877

Abstract

Bacillus sp. PSA10 and Bacillus sp. PPK5 were two indigenous strain amylolytic bacteria from SoutheastSulawesi that have ability to produce bioplastic poly-β-hydroxybutyrate (PHB) from sago starch. The study wasattempted to determine the mechanism of PHB production by bacteria amylolytic was grown on sago starchcontainingmedia. Two amylolytic bacteria i.e. Bacillus sp. PSA10 and Bacillus sp. PPK5 was grown for 168 hin a mineral salts medium with sago starch as carbon source. Growth of amylolytic bacteria was monitoredby cell dry weight. Extraction of PHB was done by N-hexane acetone-diethyl ether method and PHB contentwas quantifi ed with UV spectrophotometer at 235 nm. Glucose level was determined by using kit of glucoseGOD 10” and was quantifi ed with spectrophotometer at 500 nm. Sago starch concentration was determinedby phenol method using specthrophotometer at 490 nm. The result of the study showed that Bacillus sp.PSA10 was produced PHB up to 66,81 % (g PHB/g cell dry weight) at 48 h and Bacillus sp. PPK5 up to 24,83% (g PHB/g cell dry weight) at 84 h. Bacillus sp. PSA10 has ability to converse sago starch to be PHB directlywithout glucose accumulation in the media, whereas Bacillus sp. PPK5 have to accumulate glucose as productof sago starch hydrolysis to produce of PHB. PHB synthesis by Bacillus sp. PHB production on sago starchof the Bacillus sp. PSA10 was found to be growth-associated whereas Bacillus sp. PPK5 was found to be nongrowth-associated. Therefore, two indigenous amylolytic bacteria were having of difference in biosynthesismechanism of PHB in sago starch medium and their characteristics of PHB synthesis should be consideredin developing cultivation methods for the effi cient production of PHB. Keywords : Production, PHB, Amylolytic bacteria, Sago starch.
Phylogenetic relationship of Gram Negative Bacteria of Enterobacteriaceae Family in the Positive Widal Blood Cultures based on 16S rRNA Gene Sequences Sri Darmawati; Langkah Sembiring; Widya Asmara; Wayan T. Artama; Masashi Kawaichi
Indonesian Journal of Biotechnology Vol 19, No 1 (2014)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (431.864 KB) | DOI: 10.22146/ijbiotech.8635

Abstract

The purpose of this study was to analyze the phylogenetic relationship of Gram negative bacteria (3strains of Salmonella typhi, 1 strain of Escherichia coli, 1 strain of Serratia marcescens, and 3 strains of Enterobactercloacae) of Enterobacteriaceae family in positive Widal blood cultures based on 16S rRNA gene sequences. Theresults respectively showed that each two 16S rRNA gene clones of Serratia marcescens KD 08.4 had a closerelationship with 16S rRNA gene of Serrratia marcescens ATCC 13880 (similarity: 99.53-99.8%), Eschericia coliBA 30.1 with Eschericia coli ATCC 11775T (similarity: 99.38-99.67%), Salmonella typhi BA 07.4, Salmonella typhiKD 30.4, and Salmonella typhi SA 02.2 with Salmonella typhi ATCC 19430T (similarity: 99.4-100%) as well as theisolates of Enterobacter cloacae SA 02.1, Enterobacter cloacae BA 45.4.1, one 16S rRNA gene clone of Enterobactercloacae TG 03.5 with Enterobacter cloacae ATCC 23373 (similarity: 99.0-99.87%).