UNTUNG MURDIYATMO
PTP Nusantara XI, Jl. Merak No. 1, Surabaya 60175 Telp. (031) 3524596

Published : 6 Documents
Articles

Found 6 Documents
Search

The Potency of Dextranase from Arthrobacter sp. Strain B7 as Dental Plaque Removal BAKTIR, AFAF; ZAINI, NOOR CHOLIES; MURDIYATMO, UNTUNG; KUNTAMAN, KUNTAMAN
HAYATI Journal of Biosciences Vol 12, No 4 (2005): December 2005
Publisher : Bogor Agricultural University, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.4308/hjb.12.4.162

Abstract

Dextranase of Arthrobacter sp. strain B7 (B7DEX enzyme) was characterized in this study. This enzyme hydrolyzed sucrose and dextran, but not other glucans (starch, nigeran, cellulose, -soluble glucan). It also hydrolyzed glucan from dental plaque with the activity of 7.38 +/- 66 U/ml, where the activity toward dextran was 31.88 +/- 1.24 U/ml. The enzyme exhibited the pH optimum of 7 and the temperature optimum of 50 0C. Its optimum stability was at pH 7 and 50 0C. The enzyme was inhibited by Fe3+, Cu2+, Zn2+, and Ag+, but not by the anionic detergent (SDS) and the nonionic detergent (Triton-X). The enzyme was activated by Ca2+, Na+, Mg2+, and saliva.
Fed-Batch Fermentation Processes to Produce Dextranase from of Streptococcus sp. B7 Satiawihardja, Budiatman; Wibisono, Beni; Murdiyatmo, Untung
Jurnal Mikrobiologi Indonesia Vol 4, No 2 (1999): JURNAL MIKROBIOLOGI INDONESIA
Publisher : Jurnal Mikrobiologi Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

The research aimed to develop fermentation technique on dextranase production from the bacterial isolate ofStreptococcus sp. B7 using fed-batch Fermentation system. The production was done in two litre Fermentor with flow rate ofmedium addition at 19 mI/hr after 24 hours until 72 hours of incubation process. The variable conditions were pH of 7 and 8and agitation speeds of 300 and 500 rpm. Maximum production was achieved at 500 rpm and p11 8 that produced enzymeactivity of 920 U/mI. The best result of some kinetic parameters were as follows : production p = 920 U/mI, productivity Qv =16.43 U/mllhr, dextranase specific activity 17.68 U/mg protein, yield of product over cell Yp/x = 696.47 U/g cell and specificproductivity q, = 12.45 U/g celllhr.
Purification of alfa-Amylase from Bacillus stearothermophilus by Ultrafiltration Membrane Lestari, Puji; Richana, Nur; Murdiyatmo, Untung
Jurnal Mikrobiologi Indonesia Vol 5, No 1 (2000): JURNAL MIKROBIOLOGI INDONESIA
Publisher : Jurnal Mikrobiologi Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

The objective of this experiment was to evaluate the optimum conditions of cc-amylase of Bacillus slearotherinophiluspurification by ultrafiltration and the step of a-amylase purification from indigenous isolate. Culture filtrate frombioreactor was separated by microfiltration membrane with a pore sIze of 0.2 tm. The aupernatant was purifie again byultrafiltration system membrane with cut off 30 000 Dalton. Treatments of cz-amylase purified by ultrafiltration werecarried out at flow rate of 30,45 and 60 mI/minute, and concentrated by about 5, 10 and 15 tImes. The crude enzymesresulted From ultrafiltration were precipitated with acetone. The results showed that the optimum condition ofultrafiltration was using flow rate of 30 mI/minute and concentrated by about 10 times. At the optimum condition ofultrafiltration, the specific activity of ci-amylase was of 6 686.6 U/mg with 2.3 fold purification factor. The effect of flow ratedecreased the total enzyme activity, specific activity and yield. The concentration disposal could decrease total activity andprotein, but not always reduced specific activity of the enzyme. Purification of crude enzyme by ultrafiltration and acetonereduced the total activity, total protein and yield, but specific activity and purification factor increased. Ultrafiltrationfollowed by acetone precipitation, gave enzyme specific activity of 18155.4 U/mg, purification factor of 6.3 and yield of20%, respectively. Zymogram analysis using Native-Polyacrylamide Agarose Gel Electrophoresis indicated´ ci-amylase ofapproximately 192 932.8 Da.
Optimization of Ethanol Production from Palmyra Sap by Zymomonas mobilis using Response Surface Methodology (RSM) CHRISNASARI, RUTH; WARDANI, AGUSTIN KRISNA; MURDIYATMO, UNTUNG
Microbiology Indonesia Vol 5, No 2 (2011): June 2011
Publisher : Indonesian Society for microbiology

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Ethanol is believed to be one of the best alternatives to replace gasoline, because ethanol is a renewable energy source and environmentally friendly. The present study focuses on the optimization of palmyra sap as a source for ethanol production. Statistical experimental design using Box-Wilson central composite design (CCD) was used to optimize the quantitative effects of sugar, urea, and inoculum concentration on ethanol production. It was found that palmyra sap could be used as a substrate for ethanol production using Zymomonas mobilis (NRRL B-14234). A maximum ethanol concentration of 58.97 g L-1 was obtained after optimizing the parameters of fermentation. The optimum values of sugar, urea, and inoculums concentration were 206.01 g L-1, 3.16 g L-1, and 23.05% (v v-1), respectively, with ethanol yield of 0.3039 g g-1. A high similarity was observed between the predicted and experimental results, which reflected the accuracy and applicability of RSM to optimize the process for ethanol production.
The Potency of Dextranase from Arthrobacter sp. Strain B7 as Dental Plaque Removal BAKTIR, AFAF; ZAINI, NOOR CHOLIES; MURDIYATMO, UNTUNG; KUNTAMAN, KUNTAMAN
HAYATI Journal of Biosciences Vol 12, No 4 (2005): December 2005
Publisher : Bogor Agricultural University, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.4308/hjb.12.4.162

Abstract

Dextranase of Arthrobacter sp. strain B7 (B7DEX enzyme) was characterized in this study. This enzyme hydrolyzed sucrose and dextran, but not other glucans (starch, nigeran, cellulose, -soluble glucan). It also hydrolyzed glucan from dental plaque with the activity of 7.38 +/- 66 U/ml, where the activity toward dextran was 31.88 +/- 1.24 U/ml. The enzyme exhibited the pH optimum of 7 and the temperature optimum of 50 0C. Its optimum stability was at pH 7 and 50 0C. The enzyme was inhibited by Fe3+, Cu2+, Zn2+, and Ag+, but not by the anionic detergent (SDS) and the nonionic detergent (Triton-X). The enzyme was activated by Ca2+, Na+, Mg2+, and saliva.
Purifikasi dan Karakterisasi α-amilase Termostabil dari Bacillus stearothermophilus TII-12 Lestari, Puji; Richana, Nur; Darwis, Abdul Aziz; Syamsu, Khaswar; Murdiyatmo, Untung
Jurnal AgroBiogen Vol 7, No 1 (2011): April
Publisher : Balai Besar Penelitian dan Pengembangan Bioteknologi dan Sumber Daya Genetik Pertanian

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Purification and Characterization of Thermostableα-amylase from Bacillus stearothermophilus TII-12. PujiLestari, Nur Richana, Abdul A. Darwis, Khaswar Syamsu,and Untung Murdiyatmo. Thermostable α-amylase is apotential enzyme employed in the starch processing andwidely used in food industries, but this enzyme is stillimported. The local enzyme production would be moreeconomist and useful for its broad applications. Here wereport α-amylase from indigenous bacteria TII-12 which waspurified and characterized, as well as analyzed its hydrolysisproduct on cassava starch. The enzyme of Bacillusstearothermophilus TII-12 partially purified by ultrafiltration,acetone precipitation and gel filtration (Sephadex G-100)showed the reduced total activity, total protein and yield, butincreased the specific activity. The enzyme had a Km of 1,06mg/ml and Vmax of 1,21 mol/min, with optimal activity at pH 7and 90oC. An apparent molecular mass was of 192.932,8Dalton, as estimated by Native-Polyacrylamide Agarose Gelelectrophoresis. Its activity was inhibited by the divalentcation chelator such as EDTA and CuSO4 but activated bycalcium ion. Hydrolysis products of this enzyme on cassavastarch were glucose, dextrin, maltose and oligosaccharides.After 24 hours of hydrolysis, the concentration of glucoseand maltose reached 51.970 and 10.090 ppm, respectively.The thermostable α-amylase of TII-12 is an endo-α-amylaseand prospective to be applied on starch liquefaction withhigh temperature process.