Poultry waste management using microorganisms

Abstract

Several million tonnes of feather are produced annually as a byproduct of poultry processing industries and poultry farms which apart from polluting soil and water also plays important role in spread of various human ailments such as dermatophytic infections, chlorosis, mycoplasma fowl cholera and avian influenza. Feather waste being rich in keratin protein are difficult to degrade as the polypeptide are densely packed and stabilized with numerous hydrogen bonds, disulphide bonds and hydrophobic interactions. Despite of recalcitrant nature of keratin proteins, keratin waste do not accumulate in nature confirming the presence of natural decomposers. A number of dermatophytes, saprophytic fungi, bacteria and actinomycetes are known to degrade keratin by virtue of a particular class of endoproteases called keratinase(s) that display the capability to degrade structure conforming keratin protein. Feathers are composed of approximately 90% keratin protein thus can be a potential source of proteins and amino acids. Application of keratin degrading microorganism have provided appropriate technology for bioconversion of poultry feather into nutritionally enriched feed stuffs and essential amino acids. Waste feathers have also been used as substrate for production of proteolytic enzymes including keratinases. Enzymes produced by keratinolytic microorganisms have also find applications in prion degradation and peptide synthesis. Recent researches on utilization of feather waste are on the way to develop low cost hydrogen storage system from carbonized chicken feather fiber. The conventional methods employing incineration or chemical transformation of feather usually resulting in production of low grade feather meal thus the methods appear to be inadequate. In continuation of these developments, a new improved process has been suggested for obtaining biodiesel fuel in addition to the production of feather meal from chicken feathers. However, biotransformation process can be further improved by involving certain steps of biofuel production to make the process cost effective for the production of high grade feather meal from waste feather.