A comparative study about decomposable ability of two thermophilic bacteria to keratin

Abstract

Keratin is a refractory protein which widely exists as animal hairs, feathers and so on in nature. Because the structure of keratin becomes loose and easy to be degraded at high temperatures, thermophilic bacteria and keratinases have attracted extensive attention. Bacillus sp. WF146 and Thermoactinomyces sp. CDF are two thermophilic bacteria isolated from soil in our previous studies. They can both degrade keratin well. By changing the nitrogen source in the medium to cause nutritional stress, and monitoring protease degradation of feather substrate, we found that the expressed protease is the key to the degradation of keratin. The results showed that there were some differences in the feather degradation process of two strains, they may related to damaging disulphide bond of keratin with reducing power provided by the cells, and physics destroy the structure of feather. That is what led to their different feather-degrading characteristics.