Innitial Characterization of Keratinase By Bacillus Proteolyticus GAM 15 Isolated from Palangkaraya Peat Soil, Central Kalimantan and Its Application for Goat Skin Dehairing
Hanif Nur Rozaq, Andriyani Andriyani, and Suharti Suharti

Malang State University

Abstract

Abstract. Dehairing is one important process in leather industry. The process was generally proceed chemically which is not environmental friendly. A greener process could be done using utilizing the keratinase secreted by bacteria. A preliminary study found that bacterial isolates, from the Peat Soil Palangkaraya, Central Kalimantan, were proven to decompose chicken feathers which proved its capability to produce. This paper reports our work on the characterization of keratinase its potential to dehair goat skin. This research was conducted in several stages, they are (1) regeneration of Bacillus proteolyticus GAM 15, (2) keratinase production, (3) determination of keratinase characteristics by pH, temperature, the effect of metal ions on the enzyme activity, the type of enzyme (4) identification of Gram type and the bacterial species based on 16S rRNA gen sequence, and (5) its application for dehairing agent. The results showed that the isolate is a gram-positive bacteria with bacil cell shape. It has 100% homology with Bacillus proteolyticus. The characterization results of the keratinase enzyme were metalloprotease and activity of keratinase increased when adding Ni3+ (34,03 U/mL). This enzyme has optimum pH of 9 with an enzyme activity value of 27.26 U/mL. Furthermore, the optimum temperature of the keratinase enzyme activity at 52oC with the resulting enzyme activity of 28.63 U/mL. Crude extract of the keratinase enzyme was effective for dehairing goat skin with 72 hours of incubation time.

Keywords: Bacillus proteolyticus, keratinase, chicken feather, dehairing.

Topic: Biochemistry