Characterisation of azoreductase produced by Brevibacillus panacihumi during the decolourisation of reactive black 5

Azoreductase plays an important role in the decolourisation of azo dyes by cleaving the azo bonds in azo dye structure. In view of this, Brevibacillus panacihumi, azo dye-degrading bacteria, was used for decolourisation of Reactive Black 5 (RB5) dye. Decolourisation of RB5 was carried out by growing...

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Main Author:	Mohd. Ramlan, Masyithah Aalia
Format:	Thesis
Language:	English
Published:	2012
Subjects:	QD Chemistry
Online Access:	http://eprints.utm.my/id/eprint/40599/1/MasyithahAaliaMohdRamlanMFBB2012.pdf
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id	my-utm-ep.40599
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spelling	my-utm-ep.405992020-06-03T05:44:08Z Characterisation of azoreductase produced by Brevibacillus panacihumi during the decolourisation of reactive black 5 2012-03 Mohd. Ramlan, Masyithah Aalia QD Chemistry Azoreductase plays an important role in the decolourisation of azo dyes by cleaving the azo bonds in azo dye structure. In view of this, Brevibacillus panacihumi, azo dye-degrading bacteria, was used for decolourisation of Reactive Black 5 (RB5) dye. Decolourisation of RB5 was carried out by growing the bacteria culture in RB5 dye solution (100 mg/L) at pH 9, supplemented with glucose 0.4 % (v/v) and yeast extract 1.2 % (v/v) and incubated at 37 °C under sequential anaerobic-aerobic condition. Azoreductase was produced during which the enzyme with the highest activity obtained during the end of log phase. Since the azoreductase activity related to the decolourisation of RB5 in anaerobic condition, the cells were harvested during this condition. Then, to determine whether the enzyme produced is found intracellular or extracellular, the cells was collected via centrifugation and the cell pellet was disrupted using sonication technique, and Lowry assay was used to determine the protein concentration. Azoreductase was found to be produced intracellularly as the cell free extract has the highest specific activity of 0.334 U/mg compared to the culture supernatant (extracellular), resting cell and cell debris which has significantly lower enzyme activity of 0.034 U/mg, 0.010 U/mg and 0.200 U/mg, respectively. The optimum assay conditions for the maximum azoreductase activity were at 37 °C, RB5 dye concentration of 100 mg/L and NADH concentration of 0.2 mM. In addition, the optimum pH and Ionic liquids [emim][EtSO4] concentration was pH 7 and 70 %, respectively. Phosphate buffer, pH 7 showed a higher enzyme activity compared to the Ionic liquids as a stabiliser in azoreductase assay. Decolourisation of RB5 by azoreductase under the optimum assay conditions occured up to 93 % at 8th hour of incubation was successfully achieved. 2012-03 Thesis http://eprints.utm.my/id/eprint/40599/ http://eprints.utm.my/id/eprint/40599/1/MasyithahAaliaMohdRamlanMFBB2012.pdf application/pdf en public masters Universiti Teknologi Malaysia, Faculty of Biosciences and Bioengineering Faculty of Biosciences and Bioengineering
institution	Universiti Teknologi Malaysia
collection	UTM Institutional Repository
language	English
topic	QD Chemistry
spellingShingle	QD Chemistry Mohd. Ramlan, Masyithah Aalia Characterisation of azoreductase produced by Brevibacillus panacihumi during the decolourisation of reactive black 5
description	Azoreductase plays an important role in the decolourisation of azo dyes by cleaving the azo bonds in azo dye structure. In view of this, Brevibacillus panacihumi, azo dye-degrading bacteria, was used for decolourisation of Reactive Black 5 (RB5) dye. Decolourisation of RB5 was carried out by growing the bacteria culture in RB5 dye solution (100 mg/L) at pH 9, supplemented with glucose 0.4 % (v/v) and yeast extract 1.2 % (v/v) and incubated at 37 °C under sequential anaerobic-aerobic condition. Azoreductase was produced during which the enzyme with the highest activity obtained during the end of log phase. Since the azoreductase activity related to the decolourisation of RB5 in anaerobic condition, the cells were harvested during this condition. Then, to determine whether the enzyme produced is found intracellular or extracellular, the cells was collected via centrifugation and the cell pellet was disrupted using sonication technique, and Lowry assay was used to determine the protein concentration. Azoreductase was found to be produced intracellularly as the cell free extract has the highest specific activity of 0.334 U/mg compared to the culture supernatant (extracellular), resting cell and cell debris which has significantly lower enzyme activity of 0.034 U/mg, 0.010 U/mg and 0.200 U/mg, respectively. The optimum assay conditions for the maximum azoreductase activity were at 37 °C, RB5 dye concentration of 100 mg/L and NADH concentration of 0.2 mM. In addition, the optimum pH and Ionic liquids [emim][EtSO4] concentration was pH 7 and 70 %, respectively. Phosphate buffer, pH 7 showed a higher enzyme activity compared to the Ionic liquids as a stabiliser in azoreductase assay. Decolourisation of RB5 by azoreductase under the optimum assay conditions occured up to 93 % at 8th hour of incubation was successfully achieved.
format	Thesis
qualification_level	Master's degree
author	Mohd. Ramlan, Masyithah Aalia
author_facet	Mohd. Ramlan, Masyithah Aalia
author_sort	Mohd. Ramlan, Masyithah Aalia
title	Characterisation of azoreductase produced by Brevibacillus panacihumi during the decolourisation of reactive black 5
title_short	Characterisation of azoreductase produced by Brevibacillus panacihumi during the decolourisation of reactive black 5
title_full	Characterisation of azoreductase produced by Brevibacillus panacihumi during the decolourisation of reactive black 5
title_fullStr	Characterisation of azoreductase produced by Brevibacillus panacihumi during the decolourisation of reactive black 5
title_full_unstemmed	Characterisation of azoreductase produced by Brevibacillus panacihumi during the decolourisation of reactive black 5
title_sort	characterisation of azoreductase produced by brevibacillus panacihumi during the decolourisation of reactive black 5
granting_institution	Universiti Teknologi Malaysia, Faculty of Biosciences and Bioengineering
granting_department	Faculty of Biosciences and Bioengineering
publishDate	2012
url	http://eprints.utm.my/id/eprint/40599/1/MasyithahAaliaMohdRamlanMFBB2012.pdf
_version_	1747816561087873024

Characterisation of azoreductase produced by Brevibacillus panacihumi during the decolourisation of reactive black 5

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