Feather-Degrading Bacteria: Their Biochemical and Genetic Characteristics

Feather-degrading bacteria are a group of micro-organisms with the ability to degrade feather. They have been identified ubiquitously both in wild birds and poultry, as well as the feather waste produced by the food industry. In wild birds, they play a major role in influencing the colour of plumage and sexual selection. However, their significance for the poultry industry seems to be even greater. This branch of the food industry produces significant amounts of feather waste, which is difficult to process using the traditional chemical and physical methods. Due to the specific biochemical structure of feather, dominated by beta-keratin strengthened by numerous disulphide bonds, bacterial cultures seem to be the most economical and environment-friendly agent in the degradation of feather waste. The ability to degrade feathers is dependent on production of keratinase and disulphide reductase. The present review characterizes in detail a wide range of keratinases isolated from feather-degrading bacteria with potential application in feather waste processing. Furthermore, molecular methods of identifying and analysing the species of feather-degrading bacteria have been presented.