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

Published : 2 Documents
Articles

Found 2 Documents
Search

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.
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 | Full PDF (92.646 KB) | 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.