Study On Isolation Of A Feather-Degrading Bacterium From Grebes' Digestive Tract And Digestive Mechanism Of Feather

Grebes have a unique feather-eating behavior, but there are many suspicion and dispute on the mechanism of the digestion process and the function of feathers in the digestive tract.In this article, a bacterium with strong feather degrading ability was isolated from digestive tract of grebes, which was identified as Bacillus subtilis. From this bacterium, a secretory keratinase was purified with the molecular weight of 42KDa. The optimum pH of the keratin-degrading reaction was 6.5, which was equal to pH value in the digestive tract of grebes. It was confirmed that the feathers eaten by grebes serve to protect the wall of stomach. The feather net in the third room of stomach could filter food and prevent petrous food such as bones from coming into the alimentary canal. Furthermore, feathers could be digested and supplied the specific amino acid (cysteine and cystine) to satisfy the needs of feather renewal. Thus, the energy can be used by self-systematic circulation.