Nutritional improvement of feather protein by treatment with microbial keratinase

Grazziotin, Adriane; Pimentel, Fernanda A.; Jong, Erna Vogt de; Brandelli, Adriano

doi:10.1016/j.anifeedsci.2005.06.002

Cited by 186 publications

(144 citation statements)

References 33 publications

Supporting

Mentioning

137

Contrasting

Unclassified

Order By: Relevance

“…These conditions lead to changes in the protein structure and degradation of amino acids. Another disadvantage of this method is high cost as a result of high energy requirement [2]. Thus, cheaper techniques preventing unwanted changes of amino acids are needed.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Alternative Methods of Preparation of Soluble Keratin from Chicken Feathers

Sinkiewicz

Śliwińska

Staroszczyk

et al. 2016

Waste Biomass Valor

147

View full text Add to dashboard Cite

Huge amount of keratinous waste, especially birds' feathers, demands more value-added application instead of dumping. The present work reports the results of experiments aimed at preparing soluble keratin useful for novel bioproduct formation. The effect of thermo-chemical treatments with various reducing agents, i.e. 2-mercaptoethanol, dithiothreitol, sodium m-bisulphite, and sodium bisulphite, as well as sodium hydroxide, on the yield of keratin extracted from chicken feathers was determined. It was shown that after 2-h reduction with 2-mercaptoethanol and sodium bisulphite, the yield of soluble keratin was about equal and amounted to 84 and 82 %, respectively. The cheaper and harmless sodium bisulphite additionally decreased the extraction time to 1 h with the same yield. Moreover, treatment of the feathers with 2.5 % NaOH further improved the extraction effectiveness by increasing the yield up to 94 %. The results of the study demonstrate the viability of hydrolytic processes to obtain soluble keratin useful for biodegradable film formation for food application, that are harmless and more effective than solubilization by reduction of the disulphide bonds. Graphical Abstract

show abstract

Section: Introductionmentioning

confidence: 99%

“…The bird feathers consist of approximately 90 % keratin. The worldwide annual feather offal amounts to about 8 9 10 5 tonnes [2]. Usually it is deposited in landfills.…”

Section: Introductionmentioning

confidence: 99%

Alternative Methods of Preparation of Soluble Keratin from Chicken Feathers

Sinkiewicz

Śliwińska

Staroszczyk

et al. 2016

Waste Biomass Valor

147

View full text Add to dashboard Cite

show abstract

“…Owing to their insoluble nature, feathers are resistant to degradation by common microbial proteases. Thus, the several million tons of feathers generated annually by the poultry industry leads to troublesome environmental pollution and wastage of protein-rich reserve (Onifade et al, 1998;Gousterova et al, 2005;Grazziotin et al, 2006). Keratinase enzymes have been found to be an effective feather degrading enzyme useful for degradation of feather, hair and chicken wastes.…”

Section: Discussionmentioning

confidence: 99%

Biochemical and Molecular Characterization of a New Local Keratinase Producing Pseudomomanas sp., MS21

Tork¹,

Aly²,

Nawar³

2009

Asian J. of Biotechnology

View full text Add to dashboard Cite

This study aimed to isolate and identify a new local bacterial strain, able to completely degrade keratin-rich wastes into soluble and useful materials which can be used in many proposes. Bacterial keratinases are of particular interest because of their action on insoluble keratin substrates and generally on a broad range of protein substrates. These enzymes have been studied for de-hairing processes in the leather industry and hydrolysis of feather and keratin. Samples from poultry industry wastes, soil, water, fodder and feather were collected from different places in Jeddah, Saudi Arabia. Each sample was plated on feather meal agar plates containing 5 g LG feather as the sole carbon and nitrogen source and 1 the obtained colonies were selected, purified and their growth were detected on skimmed milk agar and feather meal broth media. The well grown isolates on feather meal agar which producing the largest clearing zone on skimmed milk plate were selected for keratinase assays. Out of 23 bacterial isolates, 7 isolates were selected. The best keratinase producing bacterium kera MS21 was selected and identified based on morphological, physiological and some biochemical characteristics. It was recorded as a species belonging to the genus Pseudomonas and identified as Pseudomonas sp. The results of identification were confirmed by 16S rDNA studies. Precipitation and purification of the keratinase enzyme in addition to factors affecting enzyme activity were studied. The enzyme molecular weight was determined to be of 30 KDa using sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis. The optimum temperature and pH were determined to be 37°C and pH 8.0, respectively. The effect of some proteases inhibitors and activators were also studied.

show abstract

“…Applicatory potential of keratinolytic proteases or keratin hydrolysates obtained with Bacillus bacteria has been recently explored with special regard to certain branches of industry. Grazziotin et al [18] evaluated the nutritional quality of chicken feather hydrolysates obtained in culture of B. licheniformis. Also, purified keratinase from B. licheniformis ER-15 was applied for bioconversion of feathers into feather meal of improved dietary value [14].…”

Section: Introductionmentioning

confidence: 99%

“…It allows for production of feather meal of improved dietary value, amino acid balance and digestibility [14,18]. Occasionally, combined chemical and enzymatic hydrolysis also proves to be advantageous [10,19].…”

Section: Introductionmentioning

confidence: 99%

Enzymatic Degradation of Pretreated Pig Bristles with Crude Keratinase of Bacillus cereus PCM 2849

Łaba

Chorążyk

Pudło

et al. 2016

Waste Biomass Valor

View full text Add to dashboard Cite

Purpose The aim of the study was to apply and optimize the process of bioconversion of pig bristle waste using keratinolytic enzymes of Bacillus cereus PCM 2849, and to evaluate the amino acid composition of the resultant hydrolysate. Methods Hydrolysis with concentrated culture fluid of B. cereus was applied for bioconversion of pig bristles, after thermo-chemical pretreatment with sulfite. The effect of substrate concentration, sulfite concentration during pretreatment and reaction temperature on the release of amino acids was determined using Box-Behnken design. Amino acid composition of the obtained hydrolysate was determined by HPLC. Structural condition and substructural changes of the residual substrate were evaluated with SEM microscopy and FTIR spectroscopy. Results The applied enzymatic preparation for bristle biodegradation was verified to contain multiple proteases of a wide molecular weight range. A regression model was developed, in which influential parameters were: linear effect of substrate concentration, followed by quadratic effects of reaction temperature, substrate concentration and pretreatment. Optimum reaction conditions were also determined. The resultant hydrolysate was rich in branched-chain amino acids. Residual substrate was detriorated and sulfitolytic cleavage of disulfides and alteration of protein secondary structures was confirmed. Conclusions Application of B. cereus crude keratinase allowed for partial hydrolysis of pig bristles, preceded by sulfitolytic pretreatment. A regression model was built to describe the process of hydrolysis to release free amino acids, at constant enzyme load. Hydrolysis in given conditions allowed to obtain hydrolysate rich in branched chain amino acids. The presented process poses an alternate way of management over pig bristles, a hard-to-degrade keratinous waste.

show abstract

Nutritional improvement of feather protein by treatment with microbial keratinase

Cited by 186 publications

References 33 publications

Alternative Methods of Preparation of Soluble Keratin from Chicken Feathers

Alternative Methods of Preparation of Soluble Keratin from Chicken Feathers

Biochemical and Molecular Characterization of a New Local Keratinase Producing Pseudomomanas sp., MS21

Enzymatic Degradation of Pretreated Pig Bristles with Crude Keratinase of Bacillus cereus PCM 2849

Contact Info

Product

Resources

About