Immobilization of phytase purified from a thermophilic Geobacillus sp. TF16 on the different carriyng materials, characterization of immobilized enzymes and investigation of phytate degredation effect of its from a natural nutritional source

In this study, phytase purified from Geobacillus sp. TF16 was immobilized on Chitosan and Ca-Alginate. Temperature and pH optimums of the enzyme immobilized on chitosan were found to be 95oC and 5.0, respectively. Temperature and pH optimums of the enzyme immobilized on Ca-Alginate were found to be 75oC and 3.0, respectively. The enzyme activity of immobilized on chitosan was preserved approximately 85% after 24 hours incubation at 4 oC, 35oC and 95oC. The enzyme activity of immobilized on Ca- Alginate was preserved approximately 80% after 24 hours incubation at 4oC, 35 oC and 75oC. In the study of thermal stability, enzyme activity was conserved almost all of activity after 4 hours at 4oC and 24 hours at 35, 75 and 95°C. In the presence of sodium phytate as a substrate, Vmax and Km values were calculated as 3401.36 U/mg and 2.38 mM, respectively, for the enzyme immobilized on chitosan. Vmax and Km values were calculated as 5011.12 U/mg and 7.5 mM, respectively, for the enzyme immobilized on Ca-Alginate. Additionally, it was detected that some metal ions affected the enzyme activity at different ratios. In the presence of EDTA, the enzyme activity was inhibited slightly. In the presence of proteases, the activity of enzyme immobilized on chitosan is conserved approximately 76% at 37oC after 1 hour incubation. The activity of enzyme immobilized on Ca-Alginate was conserved approximately 60% at 37oC after 1 hour incubation. The enzyme immobilized on chitosan hydrolyzed approximately 24% of soymilk phtate at 95oC after 4 hours. The enzyme immobilized on Ca-Alginate hydrolyzed approximately 33% of soymilk phtate at 95oC after 4 hours.