Feather waste is generated in large amounts as a by-product of commercial poultry processing. This residue is almost pure keratin, which is not easily degradable by common proteolytic enzymes. Eight strains of Bacillus, isolated from decomposing feathers were tested for the hydrolysis of feather wastes in the laboratory. Among these strains, Bacillus cereus KB043 was the best feather degrading organism when grown on basal medium containing 1% hen feather as sole source of carbon and nitrogen. It caused 78.16 ± 0.4 % degradation with a significant release of soluble protein (1206.15 ± 14.7 µg mL-1) and cysteine (20.63 ± 0.4 µg mL-1) in the cultivation fluid. The strain also showed the highest level of keratinase activity (39.10 ± 0.4 U mL-1). These data indicates that the Bacillus cereus KB043 could be useful in management of poultry wastes

A keratinolytic bacterium Elizabethkingia meningoseptica KB042 was isolated from dropped off feathers. The bacterium showed 82.50 ± 0.3% feather degradation when grown on medium containing 10 g/l chicken feathers with initial pH 7.0 at 37°C, 150 rpm in 6 days. The pH of the medium was increased up to 10.02 ± 0.10 during 6 days of incubation. Soluble protein and amino acids concentration in the culture fluid was also found increased until the end of incubation. During the cultivation of strain KB042 on feather as sole source of carbon and nitrogen, the maximum cysteine release was noted on the 3rd day. Varying feather concentration 1.0-2.0% in basal medium resulted in soluble protein release between 1814.42 and 1954.61 μg/ml. The amino acid concentration was found to be maximum, i.e. 937.85 ± 11.9 μg/ml in the cultures grown with 2% feather. The hydrolysate was also found rich in essential amino acids valine, tryptophan, threonine, leucine and cysteine and contains minor amount of methionine and arginine. These data indicate a potential biotechnology for biotransformation and utilization of feather keratin as a source of protein which can be used as animal feed after successful animal trials.

Alkaline protease was produced by Elizabethkingia meningoseptica KB042 using waste chicken feathers as substrate. The specific activity of alkaline protease in the culture filtrate and ammonium sulfate precipitate (60%) was 174.90 and 487.52, respectively. This enzyme displayed optimum activity at 60°C and pH 10.0 and retained more than 65% of its optimum activity at pH 9.0 and 11.0. The apparent molecular weight of the enzyme as determined by SDS-PAGE was 66 kDa. The culture filtrate and its protein precipitate were found to posses dehairing activity, indicating its potential in the leather processing industry. Microscopic observation confirmed that the hairs recovered from enzyme-treated skin were intact. The results suggest that chicken feathers can be used as potential substrate for the production of dehairing enzyme using the above strain.

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