Comparing Keratinase Production and Activity Between Slow Feather Degrading Bacteria and Fast Feather-Degrading Bacteria

Student: Jemil Ahmed
Mentor: Laura Tuhela-Reuning (Department of Botany-Microbiology) and Suren Ambegaokar (Department of Botany-Microbiology)

Certain bacteria have feather degrading abilities. Some of these bacteria degrade feathers faster than others. I’m studying the biochemical differences between the fast and slow degrading bacteria.

Feathers are made up of a protein called β-keratin that can be degraded by an enzyme called keratinase. Three Bacillus spp. isolated from songbird plumage were selected because they degraded feathers at different rates. However, why these bacteria degrade feathers at different rates is unknown. Previous research involving differences in the keratinase amino acid sequence of fast and slow degraders did not correlate with keratin degradation rates. In addition, differences in promoter sequences of keratinase in the different strains had no impact on the rate of keratin degradation. We are investigating two hypotheses to better understand the difference in degradation rates. One hypothesis is that fast degrading strains produce more keratinase than slower degrading strains, and the expression of the keratinase gene during degradation can be quantified to determine whether this is the case. The other hypothesis is that fast degrading bacteria produce reducing agents that change the structural integrity of β-keratin making it easier for keratinase to degrade the feathers. This will be tested by examining thiol residues after reduction of disulfide bonds in keratin.