keratin production by decomposing feather waste using some local bacillus spp. isolated from poultry soil

background; feather waste is generated in large amounts as a by-product of commercial poultry processing. the main component of feather is keratin. the main purpose of this study was to identify bacillus spp. (the keratinolytic bacteria) that are able to degrade the feather for producing keratin. methods; bacillus spp. were isolated from the waste of poultries located in miyaneh city. the bacteria were grown on basal medium containing 1% hen feather as the sole source of carbon ,nitrogen, sulfur and energy at 27ºc for 7 days. then,the isolates capable of feather degrading were identified. the bradford method was used to assay the production of keratin in the feather samples. different ph and temperatures were studied to determine the best conditions for production of keratinase enzyme. results; seven bacillus spp. including: b. pumilis, b. subtilis, b. firmus, b. macerance, b. popilliae, b. lentimorbus and b. larvae were found to be able to degrade the feather with different abilities. conclusion; b. subtilis was found to be most productive isolate for keratinase enzyme production.