Jani and Patel

keratin at temperatures higher than 50°C . All these reports

microbes for improvement of feather as poultry feed has

match with our result as our protease was also found

been extensively reviewed by Onifade et al., (1998).

having similar characteristics molecular mass 18.4 KDa

Feather meal is relatively inexpensive and is shown to

and a serine protease. The activity of keratin degrading

be superior to soybean meal in terms of total cysteine,

protease is normally associated with serine proteinase

valine and threonine content, and the hydrolyzed meal

(Lin, X., et al., 1992, Bressolier et al. , 1999), but not all

can replace soybean meal at 7% dietary level. The crude

serine type proteases are able to degrade keratin (Eggen

enzyme can also serve as a neutraceutical product, leading

H., et al., 1990). The keratinolytic strain Streptomyces

to significant improvement in broiler performance. In

pactum DSM 40530 produces a combination of serine

addition, nutritional enhancement can be achieved by

proteinases and metalloproteinases (Böckle, B., et al. ,

hydrolysis of feather meal/raw feather using keratinolytic

1995). Feather degradation by Streptomyces sp. 594 has

microorganisms. The use of keratinolytic microorganisms

also been reported (De Azeredo, L., et al., 2006).

may represent an alternative for the development of

nitrogen sources for fertilizer utilization. The enzymatic

Conclusion

capability of the feather-degrading bacteria to accelerate

The use of keratinolytic enzymes is becoming attractive

the composting of dead chickens or feather waste could

in biotechnological applications. The enzymes are used

be an economical and environmentally safe method of

for removing hair and feather in the poultry industry,

recycling these organic materials into high-nitrogen

upgrading of feather meal, converting feather into feed

fertilizers (Hagihara, B., 1958).

protein, and clearing obstructions in the sewage system

(Gradisar, H., et al., 2000, Pissuwan, D, and Suntornsuk,

References

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The requirements of amino acids in animals are well

Böckle, B. and Müller, R. 1997. Reduction of disulfide bonds

defined in various sets of recommendations such as

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those of NRC (National Research Council), USA, etc.

Requirements vary depending on the species and age

Böckle, B., Galunsky, B., Müller, R. 1995. Characterization of a

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Bressollier, P., Letourneau, F., Urdaci, M., Verneuil, B. 1999.

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Purification and characterization of a keratinolytic serine

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Bressollier, P., Letourneau, F., Urdaci, M., Verneuil, B. 1999.

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Purification and characterization of a keratinolytic serine

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Cheng, S.W., Hu, H.M., Shen, S.W., Takagi, H. 1995.

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et al., , 1998). The application of keratinases/keratinolytic

activity

from

the

broth

of

a

feather-degrading

486