Keratinase Production from Cattle Horn Waste by Abattoir-Derived Bacterial Isolates in Kwara State, Nigeria
DOI:
https://doi.org/10.33003/fjs-2026-1018-5982Keywords:
Abattoir Soil, Cattle Horn Waste, Keratinase, Proteolytic Screening, Bacillus cereus, Lysinibacillus fusiformisAbstract
Cattle horn is a keratin-rich animal by-product whose compact protein structure makes it resistant to ordinary proteolytic degradation. Microbial keratinases provide a biological approach for converting keratinous waste into soluble products. This study aimed to isolate bacteria from abattoir soil, screen the isolates for extracellular proteolytic activity, identify the selected isolates, and evaluate keratinase activity during submerged fermentation with cattle horn powder. Five soil samples were collected from five spots across two locations at Akerebiata Abattoir, Ilorin, Kwara State, Nigeria, at a depth of 5 cm below the top soil. Six bacterial isolates were recovered on horn meal agar and screened on skim milk agar for extracellular proteolytic activity. The selected isolates were identified by 16S rRNA gene sequencing and BLAST analysis. Keratinase production was evaluated by submerged fermentation in 250 mL vessels containing 100 mL production medium, using 5 mL inoculum at 37 °C and 120 rpm for 14 days. Fermentation was conducted in three biological replicates, and enzyme assays were performed in duplicates. Six bacterial isolates were recovered. A₁ and B₃ produced hydrolysis halos of 18.00 ± 0.04 mm and 22.00 ± 0.025 mm, respectively. BLAST analysis identified isolate K1 as Bacillus cereus and isolate K2 as Lysinibacillus fusiformis. K1 had a sequence length of 1518 bp, 99.34% identity, 100% query coverage and an E-value of 0.0 against accession GQ406846.1. K2 had a sequence length of 1516 bp, 99.93% identity, 100% query coverage and an E-value of 0.0 against accession OQ568519.1.
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Copyright (c) 2026 Majekodunmi Racheal Adedayo, Kate Rachael Imeje, Elizabeth Ajiboye Adeyinka, Frank Olakunle Otuyelu
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