Daya Tahan Simpan Protease Bacillus stetrothermophillus, B. subtilis dan B. licheniformis

Abstract

The protase filtrate of B. stearothermophillus grown in liquid tofu waste supplemented with tapioca waste was stable up to 19 days of storage at 4 'C. Addition of 1 % sorbitol increased the storage life. After 53 days of storage, the enzyme activity was still maintained at 59% level. Addition of CoCI, and glycerol were not effective. When the protease was coagulated by addition 4 70% ammonium sulphate and further diluted in 0.02 M phosphuted bu.er, the enzyme was more stable during storage. The activity of protease produced from B. subtilis grown in liquid tofu waste supplemented with tapioca waste was detected up to 35 days of storage. Upon addition of 1 % sorbitol, the activity by 75 days of storage was still at 39% of the original activity. Addition of 2 mM CoCl2 could maintain the enzyme activity. After 75 days of storage, 20-30% of activity was still detected. Addition 420% ammonium sulphate was also affective; after 60 days of storage, the loss of activity was only 10 percent. Protease filtrate from B. lidtenifonnis grown in liquid tofu waste supphented with gluoose was much more stabb than the other two protease . At 4-1@C, the activity was still good up to 10 months of storage. When 1 % sorbitol was added to the enzyme filtrate and stored at 4-10°C. no significant effect was detected. Addition of 1 % glycerol inmased the enzyme activity only during the first month of storage. Milion of2 mM MnC12 imased the activity during the first-sewnd month 4 storage, after that the divalent cation tend to demase the activity. Addition of other divalent cation such as 2 mM CoCI, and 2 mM CaCI, tend to rcdw the activity of enzyme. When stored at roow temperature, the enzyme activity decreased to 50% after 2 month. During storage at room temperature, addition of sorbitol adn glycerol were quite in maintaining the stability while addition of divalentcation (MnCI, COG and CaC12 ) wre not gktive. Analysis of the effect of several additives upon kinetic parameters of the enzymes. Km (Michaelis Menten Constant) and Vmax (Matimum velocity), showed diverse pattern.