The Motility and Chemotaxis of Bacillus spp. Isolated from Songbird Plumage


Madeline Vroom

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Bacillus spp. isolated from the microbial ecosystem of songbird plumage are motile, chemotactic bacteria that are known to utilize feathers as a source of nutrients by degrading the protein β-keratin. Given the functional importance of maintaining feather quality, the preen oil birds distribute across their feathers is thought to provide protection against feather-degrading bacteria, although it is unclear in what capacity it does so. Preliminary data suggests that the viscosity of preen oil may function as a physical barrier against the chemotactic movement of Bacillus towards areas of feather damage where amino acids are available, thereby preventing further feather deterioration. We studied feather-degrading Bacillus spp. isolated from songbird plumage to characterize their motility and chemotactic response towards amino acids present in the degradation of β-keratin. Bacillus spp. were screened and those with a high percentage of motility were selected for further study. Growth curves and motility screenings were performed for each isolate. From the data gathered, the Bacillus isolate 4201 TV was chosen as a candidate for chemotaxis assays. The chemotactic response of 4201 TV was determined via quantitative chemotaxis assays using modified Palleroni chambers and 250 μM and 750 μM solutions of pro line as chemoattractants. Our findings indicate that Bacillus spp. isolated from songbird plumage are chemotactic towards proline, an amino acid found in β-keratin. Future studies are aimed at characterizing the chemotactic response of Bacillus towards amino acids other than proline present in the degradation of β-keratin. Also, to elucidate the possible connection between the chemotaxis of avian Bacillus spp. and the use of preen oil by birds, quantitative viscosity assays will be done using dilute agar solutions to mimic the viscosity of preen oil and determine its effect on the chemotactic response of Bacillus spp.

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Laura Tuhela-Reuning

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