Indonesia possesses tremendous marine resources. Therefore, their marine products are appropriate for exploration. In the prior study, bacteria generating keratinase enzyme have isolated from local fish market trash. The keratinase may hydrolyze keratin on the skin. Surrounding parameters, such as temperature, pH, and incubation duration, are the factors affecting the activity of the enzyme. This study aims to isolate and characterize keratinase, and optimize its production. The enzyme from Bacillus cereus BRAW_KM was the main material utilized in this research. First, the keratinolytic bacterium was isolated and investigated the properties of keratinase using native polyacrylamide gel electrophoresis (PAGE) and sodium dodecyl sulfate (SDS)-PAGE. Then, the ideal conditions of keratinase synthesis were adjusted by temperature, pH, and incubation time on enzyme activity. Of 10 isolations discovered, one isolate shows the potential as a keratinolytic bacterium, which tends to behave like Bacillus sp. The molecular weights of keratinase were 130 kDa and 95 kDa. The optimum keratinase enzyme activity from B. cereus BRAW_KM was at 29 °C, pH 9, and 90 minutes of incubation.

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