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Degradation of thiosulfate by sulfide-oxidizing enzyme produced by bacteria locally isolated from effective microorganism active solution (EMAS)

Md. Salleh, Madihah and Ashaari, Nur Suhanawati and Md. Illias, Rosli (2006) Degradation of thiosulfate by sulfide-oxidizing enzyme produced by bacteria locally isolated from effective microorganism active solution (EMAS). Regional Postgraduate Conference on Engineering and Science . pp. 631-636.

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Abstract

A potential aerobic sulfur-oxidizing bacterium (SOB) that was believed to be sulfide-oxidizing enzyme producing strain was previously isolated from Effective Microorganism Active Solution (EMAS), currently known as SO2. This gram negative bacterium was capable of growing autotrophically in sulfur-oxidizer medium, containing 4mM sodium thiosulfate that serves as an energy sources and electron donor. Sulfate ions were the expected end product of sulfide oxidation catalyzed by extracellular sulfide-oxidizing enzyme. The aims of this study are to identify and characterize the SO2 and to induce the activity of sulfide-oxidizing enzyme in this strain. The activity of sulfide-oxidizing enzyme was determined spectrophotometrically by measuring the increase of sulfate production using BaCl2 solution, while the oxidation of thiosulfate was colorimetrically determined at 460 nm. One unit of sulfide-oxidizing activity was defined as amount of enzyme required to produce 1 µmol sulfate per min per mL (U). The maximum sulfide-oxidizing activity (0.064 U) was achieved when the strain was grown at pH 5.0, 30˚C in medium containing 1% (w/v) peptone as nitrogen sources after 15 hours incubation. The specific growth rate of this strain at this condition was 0.1552 h-1, with doubling time value of 4.47 h.

Item Type:Article
Uncontrolled Keywords:sulfur-oxidizing bacteria, thiosulfate, sulfide oxidation
Subjects:Q Science > Q Science (General)
Divisions:Science
ID Code:3046
Deposited By: Mr Norahim Ibrahim
Deposited On:17 May 2007 02:30
Last Modified:18 Apr 2012 10:42

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