The aim of this study was to isolate and characterize keratinolytic thermophilic aerobic bacilli from Armenian geothermal springs. In total 20 thermophilic aerobic bacilli strains have been isolated using chicken feather enrichment cultures. Among these, four strains affiliated as Bacillus licheniformis (95–97% similarity) and Bacillus borbori (> 99% similarity) demonstrated the capability to completely degrade chicken feathers at 55°C. The highest rate of feather hydrolyses in mono-species cultures was observed with 40 g L− 1 substrate. Notably, enhanced keratin weight loss (≥ 80%) was observed in dual co-cultures involving B. borbori M14, highlighting superior degradative potential of this strain. Keratinolytic enzyme production was dedected during the late exponential growth phase, reached its maximum activity (0.013 U mL− 1) during the stationary phase, suggesting growth-associated enzyme synthesis. High-performance liquid chromatography (HPLC) of the hydrolysis end products revealed that aspartic acid and isoleucine were the predominant amino acids, followed by leucine, phenylalanine, alanine, tyrosine and glutamic acid. These findings confirm that the newly isolated strains are promising sources of keratinolytic proteases, with potential applications in circular bioeconomy based processes.