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Biodegradation of feather waste by extracellular keratinases and gelatinases from Bacillus spp
In this study, three feather degrading bacterial strains were isolated from agroindustrial residues from a Brazilian poultry farm. Three Gram-positive, spore-forming, rod-shaped bacteria and were identified as B. subtilis 1271, B. licheniformis 1269 and B. cereus 1268 using biochemical, physiologic...
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Published in: | World journal of microbiology & biotechnology 2011-06, Vol.27 (6), p.1355-1365 |
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Main Authors: | , , , , , , , , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | In this study, three feather degrading bacterial strains were isolated from agroindustrial residues from a Brazilian poultry farm. Three Gram-positive, spore-forming, rod-shaped bacteria and were identified as
B. subtilis
1271,
B. licheniformis
1269 and
B. cereus
1268 using biochemical, physiologic and molecular methods. These
Bacillus
spp. strains grew and produced keratinases and peptidases using chicken feather as the sole source of nitrogen and carbon.
B. subtilis
1271 degraded feathers completely after 7 days at room temperature and produced the highest levels of keratinase (446 U ml
−1
). Feather hydrolysis resulted in the production of serine, glycine, glutamic acid, valine and leucine as the major amino acids. Enzymography and zymography analyses demonstrated that enzymatic extracts from the
Bacillus
spp. effectively degraded keratin and gelatin substrates as well as, casein, hemoglobin and bovine serum albumin. Zymography showed that
B. subtilis
1271 and
B. licheniformis
1269 produced peptidases and keratinases in the 15–140 kDa range, and
B. cereus
produced a keratinase of ~200 kDa using feathers as the carbon and nitrogen source in culture medium. All peptidases and keratinases observed were inhibited by the serine specific peptidase inhibitor phenylmethylsulfonyl fluoride (PMSF). The optimum assay conditions of temperature and pH for keratinase activity were 40–50°C and pH 10.0 for all strains. For gelatinases the best temperature and pH ranges were 50–70°C and pH 7.0–11. These isolates have potential for the biodegradation of feather wastes and production of proteolytic enzymes using feather as a cheap and eco-friendly substrate. |
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ISSN: | 0959-3993 1573-0972 |
DOI: | 10.1007/s11274-010-0586-1 |