Bacillus subtilis B3 strain during growth in a synthetic medium with feather keratin synthesize extracellular proteases exhibiting keratinolytic activity. These extracellular enzymes take part in biodegradation of keratin, which results in the rise of concentration of peptides, free amino acids and thiol groups. Complete liquification of chicken feathers was observed within 5-7 days of bacterial culture. The tested strain in disadvantageous conditions formed a biofilm. The composition of biofilm’s exopolymeric matrix depends mainly on medium ingredients and contains 1,3-9,2 mg% of proteins and 1-5 mg% of polysaccharides. In a medium containing feather keratin as a hardly accessible source of carbon and nitrogen, the strain B.subtilis B3 formed biofilm composed of polysaccharides and proteins in 84% and 16%, respectively.

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