Keratinase from Salinivibrio proteolyticus TGS

Keratinase plays an important role in the leather tanning industry. The industry requires enzymes that are stable in a high salt environment process. One source of those enzymes is microbes that live in salt ponds. Previously, 8 halophilic isolates were isolated from Pasuruan salt pond. TG-3 and TG-6 have been characterized and tested for their ability to produce keratinase using chicken feathers with the highest activity of 5.893 U/mL and 9.685 U/mL. In this study, TG-5 isolate was characterized and tested for its ability to produce keratinase. The results exhibited the TG-5 isolate was Gram- negative with a rode shape and was not a new type of microbe because the sensitivity to the Salinivibrio proteolyticus strain DV was above 97%, which was 99.20%, and it was called Salinivibrio proteolyticus TG5. The optimum activity of TG-5 keratinase was achieved at pH 8, temperature 43 °C, 5% NaCl, and the presence of 1 mM Mg2+ ions. Optimization of keratinase production by SSF method showed day 3 of incubation, at pH 7, and humidity ratio of 1:4 (chicken feather: salt solution) with enzyme activity value of 6.094 U/mL. The results indicate that salinivibrio proteolyticcus TG-5 has potential in tanning leather.