Screening, Identification, and Optimization of Protease Producing Bacillus pumilus Strain DT-15 From Tannery Waste Disposal Site in Addis Ababa, Ethiopia.

Abstract

Bacterial proteases are valuable enzymes that accelerate the hydrolysis of peptide bonds within protein molecules. This study aimed to screen, identify, and optimize bacteria-producing protease from a tannery waste disposal site. Then, 36 morphologically distinct bacterial isolates were obtained from the Dire Tannery waste disposal site in Addis Ababa, Ethiopia. Among these isolates, DT-15 demonstrated the highest protease activity, with a clear zone of 19.00 ± 0.75 mm on skim milk agar, indicating its efficacy as a protease producer. Further morphological and molecular characterization of the most promising isolate was conducted. Based on its 16S rRNA sequence, the most effective isolate was identified as Bacillus pumilus. To enhance protease production, optimization experiments were carried out, resulting in an optimal enzyme activity of 506 ± 0.037 U/mL achieved after 60 h of incubation at 37°C and pH 7, using peptone and glucose as the nitrogen and carbon sources, respectively. Thus, the isolated bacterium has the potential to be utilized for various biotechnological applications, such as leather processing, detergent formulation, and food production. Further studies could focus on its applications in industrial processes.