UWCScholar :: Browsing by Author "Williams, Wesley Trevor"

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Screening for novel cold-adapted nitrile hydratases in Antarctic metagenornic libraries
(University of the Western Cape, 2024) Williams, Wesley Trevor; Cowan Don
Nitrile hydratases (NHase) catalyse the hydrolysis of nitriles to their corresponding amides, the first step in the nitrile degradation pathway. The second step is the conversion of the amide to a carboxylic acid, catalysed by an amidase. The NHases published to date have been isolated from mesophilic and thermophilic bacteria. The aim of this study was to identify a novel cold-adapted NHase from psychrophilic and psychrotrophic bacteria. The identification of a cold-adapted NHase is of interest for its potential use in chemical and pharmaceutical production. Enzymes isolated from psychrophilic bacteria typically have a high specific activ ity and low thermal stabi lity to cope with the inhibition of chemical reactions caused by low temperatures. However, culture based screening for these activities tend to reisolate already characterised isolates amiable to culturing. To access the majority of the bacterial biodiversity that the uncultured bacteria represent, the metagenomic approach was used to screen for nitrile degrading activity. Metage-nomic libraries constructed from soil taken from the McMurdo Dry Valleys in Antarctica were used for both functional and sequence based screens of NHases. Functional screens that were trialled were based on pH change and oligotrophic selective growth.