| dc.description.abstract | Goldsilk is silk fiber that made by human which it get from Cricula trifenestrata cocoon. Existence of proteolitic bacterias from cocoon have potential to influence quality of goldsilk. The aims of the experiment were to get proteolytic bacteria, characterize the protease enzyme and apply protease on goldsilk cocoon. A total of 26 proteolytic bacteria were isolated from good and bad cocoons. Nutrient Broth (NB) and Nutrient Agar (NA) containing 1% skim milk used as growth media. Isolate CKH 7 and CKK 7 are selected for protease production because they have the highest protease activity. CKH 7 and CKK 7 were identified as Aeromonas salmonicida ssp salmonicida and Vibrio fluvialis. Highest protease productivity reached after 9 hour incubation. Optimum protease activity of isolate CKH 7 at pH 8 and temperature 25 °C. Its activity increased by the presence of 2 mM Na2+ and Ca2+. Activity isolate CKK 7 optimum showed at pH 5, reached after 12 hour incubation and temperature 35°C. Its activity increased by the presence of 2 mM Cu2+, Co2+ and Ca2+. Protease of CKH 7 characterized as metalloprotease. Result of submerge cocoon in protease and continued by NaOH 0,1 N are fiber be clean, shiny, and not easy cut off. | en |
