Keratinase production by proteolytic micro-organisms in activated sludge and farmyard waste.

Okoroma, Emeka and Purchase, Diane and Garelick, Hemda and Abiola, Oduola (2008) Keratinase production by proteolytic micro-organisms in activated sludge and farmyard waste. In: Society for General Microbiology, Autumn Meeting, 8-11 September 2008, Trinity College, Dublin, Ireland. (Unpublished)

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Abstract

Thirty-two microbial strains from activated sludge and farmyard waste were isolated on feather-meal agar. Five of these isolates demonstrated significant proteolytic activity raising prospects of biotechnological application. The keratinolytic activity was assessed by casein-agar plate assay and further confirmed by keratinase assay using keratin azure as substrate. One of the five isolates (a Gram-positive cocci bacterium) produced the highest keratinase activity within 24h at a cell density of 5.2 x 108 CFU/mL under the optimized conditions of pH 10, 37°C and substrate concentration of 0.4 g/L. The crude extract gave an activity of 14 U/mL. Addition of carbon (starch) and nitrogen (yeast extract and peptone) sources caused a decline in enzymatic activity. The culture supernatants was purified by ultra filtration, concentrated by Amicon Ultra-15 centrifugal filter device and further purified by HiTrap affinity chromatography column. The resulting fraction has a purification factor of 108.7 and specific activity of 2000 U/mg. The molecular weight of the enzyme was determined by Matrix-assisted laser desorption/ionization (MALDI) to be 27.9 KDa.

Item Type:Conference or Workshop Item (Poster)
Research Areas:Science & Technology > Environmental Science
ID Code:3918
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Deposited On:02 Feb 2010 07:02
Last Modified:06 Feb 2013 11:52

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