en ميکروب شناسي Microbiology Research Article Research Article <div style="text-align: justify;"><span style="font-size:12px;"><span style="font-family:Times New Roman;"><b>Background:</b> The poultry industry produces a large amount of waste, including chicken feathers, which are difficult to decompose and can cause environmental pollution. Keratinase enzymes that degrade keratin may be used in poultry waste bioremediation. The objectives were to screen keratinolytic isolates, identify them, optimize culture conditions, and measure activity.<br> <b>Methods:</b> Two keratinolytic isolates were screened from poultry waste around Mashhad, Iran. They were identified, culture conditions were optimized, and activity was measured using azokeratin and turbidity absorbance.<br> <b>Results:</b> The two isolates were identified as <i>Bacillus pumilus</i> and <i>Bacillus tequilensis</i>. The optimal conditions were pH 7.0, 37&deg;C, and 48 h of incubation. The maximum keratinase activity was 120 U/mL and 100 U/mL, respectively.<br> <b>Conclusion</b>: The two Bacillus isolates showed potential for poultry waste bioremediation and keratinase production applicable to animal feed and cleaning products.</span></span></div> Keratins, Keratinase, Bacillus pumilus, Bacillus teqlensis, Poultry industry 36 41 http://mlj.goums.ac.ir/browse.php?a_code=A-10-1680-1&slc_lang=en&sid=1 Bahareh Behfar Baharbehfar55@gmail.com 100319475328460032750 0009-0008-9710-3116 No Department of Biology, Faculty of Sciences, University of Zabol, Zabol, Iran Fatemeh Haddadi haddadifatemeh@yahoo.com 100319475328460032751 100319475328460032751 Yes Department of Biology, Faculty of Sciences, University of Zabol, Zabol, Iran Mohammad Reza Sharifmoghadam fs@ferdowsi.um.ac.ir 100319475328460032752 100319475328460032752 No Department of Biology, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, Iran Hossein Kamaladini hu-kamaladiny@yahoo.com.au 100319475328460032753 100319475328460032753 No Department of Biology, Faculty of Sciences, University of Zabol, Zabol, Iran Masoumeh Bahreini mbahreini@um.ac.ir 100319475328460032754 100319475328460032754 No Department of Biology, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, Iran Azadeh Niknejad niknejad@khu.ac.ir 100319475328460032755 100319475328460032755 No Department of Cellular and Molecular, Faculty of Biological Sciences, Kharazmi University, Tehran, Iran