A new thermophilic nitrilase from an antarctic hyperthermophilic microorganism.

Several environmental samples from Antarctica were collected and enriched to search for microorganisms with nitrilase activity. A new thermostable nitrilase from a novel hyperthermophilic archaea Pyrococcus sp. M24D13 was purified and characterized. The activity of this enzyme increased as the tempe...

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Bibliographic Details
Published in:Frontiers in Bioengineering and Biotechnology
Main Authors: Geraldine V. Dennett, Jenny M. Blamey
Format: Article in Journal/Newspaper
Language:English
Published: Frontiers Media S.A. 2016
Subjects:
Online Access:https://doi.org/10.3389/fbioe.2016.00005
https://doaj.org/article/2453fd70ad634fa6813546bcd4a7eb88
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Summary:Several environmental samples from Antarctica were collected and enriched to search for microorganisms with nitrilase activity. A new thermostable nitrilase from a novel hyperthermophilic archaea Pyrococcus sp. M24D13 was purified and characterized. The activity of this enzyme increased as the temperatures rise from 70 up to 85 °C. Its optimal activity occurred at 85 °C and pH 7.5. This new enzyme shows a remarkable resistance to thermal inactivation retaining more than 50% of its activity even after 8 h of incubation at 85 °C.In addition, this nitrilase is highly versatile demonstrating activity towards different substrates such as benzonitrile (60 mM, aromatic nitrile) and butyronitrile (60 mM, aliphatic nitrile), with a specific activity of 3286.7 U mg-1 of protein and 4008.2 U mg-1 of protein respectively. Moreover the enzyme NitM24D13 also presents cyanidase activity.The apparent Michaelis-Menten constant (Km) and Vmáx of this Nitrilase for benzonitrile were 0.3 mM and 333.3 µM min-1, respectively, and the specificity constant (kcat/Km) for benzonitrile was 2.05×105 s-1 M-1.