Purification of Wickerhamomyces anomalus Keratinase and Its Prospective Application in Poultry Feed Industries

Ayandiran Aina,A O Aleshinloye,S T Akindele,C O Ezeamagu

doi:10.53704/fujnas.v10i1.345

Ayandiran Aina, A O Aleshinloye + Show 2 more

Open Access

https://doi.org/10.53704/fujnas.v10i1.345

Copy DOI

Abstract

Animal wastes emanating from cow horns, hooves and feathers are keratinous in nature which can only be degraded by keratinolytic microorganisms. Consequently, the pollution resulting from the accumulation of these wastes in response to growing livestock demand is posing a significant threat to human health and the environment. This study was carried out using cow hooves as the substrate for the production of keratinase from fungal identified as Wickerhamomyces anomalus 9 (18S rDNA gene sequencing) was isolated from soil rich hooves using basal salt agar medium and potato dextrose agar. The keratinase of the isolate was assessed using skim milk agar and the enzyme was produced by solid-state fermentation. The crude enzyme was purified using ammonium sulphate precipitation, ion exchange and gel-filtration chromatography. The specific activity of the enzyme was 0.29 U/mg with a yield of 45% and a 7.25 purification fold. The optimal pH and temperature of the enzyme were 8.0 and 60 oC respectively. The enzyme was observed to be thermo-stable at 50oC between for 30 minutes. The kinetics revealed that the Vmax was 0.384U/min with Km 86.95mg/ml. The native molecular weight of the enzyme was found to be 34KDa. There were significant differences at 95% confidence with poultry feed treated with Wickerhamomyces anomalus keratinase in moisture, ash content, crude fibre, crude fat, nitrogen content, crude protein and carbohydrate compare to the untreated feed. These results suggest an environment-friendly approach for biodegradation of cow hooves wastes for the production of keratinases, animal waste management as well as a promising tool for chicken feed additives. Keywords: Biodegradation, Chromatography, Cow hooves, Keratinase, Pollution

Highlights

Abattoir wastes often contain solid waste biomass that comprises of bones, hooves horns, undigested ingest, and occasional aborted fetus, while the liquid waste includes blood, urine, water, dissolved solids, and gut contents
Animal wastes emanating from cow horns, hooves and feathers contain keratin which can only be degraded by keratinolytic microorganisms
This study was carried out using cow hooves as substrate for the production of keratinase from fungus identified as Wickerhomyces anomalus 9 (18S rDNA gene sequencing) isolated from soil rich hooves using basal salt agar medium and potato dextrose agar

Summary

Introduction

Abattoir wastes often contain solid waste biomass that comprises of bones, hooves horns, undigested ingest, and occasional aborted fetus, while the liquid waste includes blood, urine, water, dissolved solids, and gut contents. The protein chains are packed tightly either in α- helix (α-Keratin) or in β- sheet (β- Keratins) structures which fold into final 3-dimensional form (Kim, 2007).Keratin is a sulfur-containing, insoluble, fibrous protein and the main constituent of skin, hair, nails, hooves, horns, scales, claws, and teeth. It is synthesized by keratinocytes and is resistant to degradation by general proteases (Wang, Yang, McKittrick & Meyer, 2015). The present study reports the biodegradation of cow hooves by isolated Wickerhomyces anomalus strain 9 (characterized by 18S rDNA gene sequencing) for keratinase production as well as the biotechnological potential of the keratinolytic enzyme as chicken feed supplements

Materials and Methods

Results

Discussion