Storage life of protease from Bacillus stearothermophillus, B. subtilis dan B. licheniformis

Author: Maggy T. Suhartono; Nuri Andarwulan; Ika Malikah; Mariani

Abstract: The protease filtrate of B. stearothermophillus grown in liquid tofu waste supplemented with tapioca waste was stable up to 19 days of storage at 4 degrees Celcius. Addition of 196 sorbitol increased the storage life. After 53 days of storage, the enzyme activity was still maintained at 5996 level. Addition of CoCl2 and glycerol were not effective. When the protease was coagulated by addition of 7096 ammonium sulphate and further diluted in 0.02 M phosphated buffer, 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 196 sorbitol, the activity by 75 days of storage was still at 3996 of the original activity. Addition of 2mM CoCl2 or MnCl2 could maintain the enzyme activity. After 75 days of storage, the loss of activity was only 10 percent. Protease filtrate from B. licheniformis grown in liquid tofu waste supplemented with glucose was much more stable than the other two proteases. At 4-10 degrees Celcius, the activity was still good up to 10 months of storage. When 196 sorbitol was added to the enzyme filtrated and stored at 4-10 degrees Celcius, no significant effect was detected. Addition of the 196 glycerol increased the enzyme activity only during the first month of storage. Addition of 2mM MnCl2 increased the activity during the first-second month of storage, after that the divalent cation tend to decrease the activity. Addition of other divalent cation such as 2mM CoCl2 and 2mM CaCl2 tend to reduce the activity of enzyme. When stored at room temperature, the enzyme activity decreased to 5096 after 2 months. During storage at room temperature, addition of sorbitol and glycerol were quite effective in maintaining the stability while addition of divalent cations (MnCl2, CoCl2, and CaCl2) were not effective. Analysis of the effect of several additives upon kinetic parameters of the enzymes, Km (Michaelis Menten Constant) and Vmax (Maximium velocity), showed diverse pattern.