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Kinetic characterization of glucose aerodehydrogenase from Aspergillus niger EMS-150-F after optimizing the dose of mutagen for enhanced production of enzyme.

Umbreen H, Zia MA, Rasul S - Braz. J. Microbiol. (2014)

Bottom Line: The enzyme was then purified and resulted in 57.88 fold purification with 52.12% recovery.The Michaelis-Menton constants (K(m), Vmax, Kcat and Kcat/K(m)) were 20 mM, 45.87 U mL(-1), 1118.81 s(-1) and 55.94 s(-1) mM(-1), respectively.The enzyme was found to be thermally stable and the enthalpy and free energy showed an increase with increase in temperature and ΔS* was highly negative proving the enzyme from A. niger EMS-150-F resistant to temperature and showing a very little disorderliness.

View Article: PubMed Central - PubMed

Affiliation: Enzyme Biotechnology Laboratory, Department of Chemistry and Biochemistry, University of Agriculture, Faisalabad, Pakistan.

ABSTRACT
In the present study enhanced production of glucose aerodehydrogenase from Aspergillus niger has been achieved after optimizing the dose of chemical mutagen ethyl methane sulfonate (EMS) that has not been reported earlier. Different doses of mutagen were applied and a strain was developed basing upon the best production. The selected strain Aspergillus niger EMS-150-F was optimized for nutrient requirements in order to produce enzyme through fermentation and the results showed the best yield at 2% corn steep liquor (CSL), 36 hours fermentation time, pH 5, 30 °C temperature, 0.3% KH2PO4, 0.3% urea and 0.06% CaCO3. The enzyme was then purified and resulted in 57.88 fold purification with 52.12% recovery. On kinetic characterization, the enzyme showed optimum activity at pH 6 and temperature 30 °C. The Michaelis-Menton constants (K(m), Vmax, Kcat and Kcat/K(m)) were 20 mM, 45.87 U mL(-1), 1118.81 s(-1) and 55.94 s(-1) mM(-1), respectively. The enzyme was found to be thermally stable and the enthalpy and free energy showed an increase with increase in temperature and ΔS* was highly negative proving the enzyme from A. niger EMS-150-F resistant to temperature and showing a very little disorderliness.

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Effect of pH (± SEM) on glucose aerodehydrogenase from A. niger EMS-150-F.
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f4-bmj-44-4-1105: Effect of pH (± SEM) on glucose aerodehydrogenase from A. niger EMS-150-F.

Mentions: In view of the fact that pH shows a prevailing task in the activity, as glucose aerodehydrogenase from Aspergillus niger was found to loss its activity by 12% when kept at pH higher than 8 in a stability test performed earlier (Ferreira et al., 2005). So a pH range from 4–8.5 was checked for optimum enzymatic activity. The results obtained have depicted that enzyme showed a good activity between the pH range of 4–8.5, with activity of 39.7 U mL−1 at pH 6 (Figure 4). These results are exactly same where optimum pH was obtained at 6 for A. niger glucose aerodehydrogenase (Ko et al., 2002). In contrast the enzyme produced from A. niger EMS-150-F in the present study is stable as compared to obtained from Penicillium pinophilum that was found unstable in pH range of 2–4 and above 7 (Rando et al., 1997). In another study on glucose aerodehydrogenase, the results had shown that the rate of reaction augmented with raise in pH of the medium, however as the pH became immense, the rates started to decline and showed a greatest at pH 6.5 (Lino and Teresa, 1998).


Kinetic characterization of glucose aerodehydrogenase from Aspergillus niger EMS-150-F after optimizing the dose of mutagen for enhanced production of enzyme.

Umbreen H, Zia MA, Rasul S - Braz. J. Microbiol. (2014)

Effect of pH (± SEM) on glucose aerodehydrogenase from A. niger EMS-150-F.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3958175&req=5

f4-bmj-44-4-1105: Effect of pH (± SEM) on glucose aerodehydrogenase from A. niger EMS-150-F.
Mentions: In view of the fact that pH shows a prevailing task in the activity, as glucose aerodehydrogenase from Aspergillus niger was found to loss its activity by 12% when kept at pH higher than 8 in a stability test performed earlier (Ferreira et al., 2005). So a pH range from 4–8.5 was checked for optimum enzymatic activity. The results obtained have depicted that enzyme showed a good activity between the pH range of 4–8.5, with activity of 39.7 U mL−1 at pH 6 (Figure 4). These results are exactly same where optimum pH was obtained at 6 for A. niger glucose aerodehydrogenase (Ko et al., 2002). In contrast the enzyme produced from A. niger EMS-150-F in the present study is stable as compared to obtained from Penicillium pinophilum that was found unstable in pH range of 2–4 and above 7 (Rando et al., 1997). In another study on glucose aerodehydrogenase, the results had shown that the rate of reaction augmented with raise in pH of the medium, however as the pH became immense, the rates started to decline and showed a greatest at pH 6.5 (Lino and Teresa, 1998).

Bottom Line: The enzyme was then purified and resulted in 57.88 fold purification with 52.12% recovery.The Michaelis-Menton constants (K(m), Vmax, Kcat and Kcat/K(m)) were 20 mM, 45.87 U mL(-1), 1118.81 s(-1) and 55.94 s(-1) mM(-1), respectively.The enzyme was found to be thermally stable and the enthalpy and free energy showed an increase with increase in temperature and ΔS* was highly negative proving the enzyme from A. niger EMS-150-F resistant to temperature and showing a very little disorderliness.

View Article: PubMed Central - PubMed

Affiliation: Enzyme Biotechnology Laboratory, Department of Chemistry and Biochemistry, University of Agriculture, Faisalabad, Pakistan.

ABSTRACT
In the present study enhanced production of glucose aerodehydrogenase from Aspergillus niger has been achieved after optimizing the dose of chemical mutagen ethyl methane sulfonate (EMS) that has not been reported earlier. Different doses of mutagen were applied and a strain was developed basing upon the best production. The selected strain Aspergillus niger EMS-150-F was optimized for nutrient requirements in order to produce enzyme through fermentation and the results showed the best yield at 2% corn steep liquor (CSL), 36 hours fermentation time, pH 5, 30 °C temperature, 0.3% KH2PO4, 0.3% urea and 0.06% CaCO3. The enzyme was then purified and resulted in 57.88 fold purification with 52.12% recovery. On kinetic characterization, the enzyme showed optimum activity at pH 6 and temperature 30 °C. The Michaelis-Menton constants (K(m), Vmax, Kcat and Kcat/K(m)) were 20 mM, 45.87 U mL(-1), 1118.81 s(-1) and 55.94 s(-1) mM(-1), respectively. The enzyme was found to be thermally stable and the enthalpy and free energy showed an increase with increase in temperature and ΔS* was highly negative proving the enzyme from A. niger EMS-150-F resistant to temperature and showing a very little disorderliness.

Show MeSH
Related in: MedlinePlus