Continuous degradation of maltose by enzyme entrapment technology using calcium alginate beads as a matrix |
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Authors: | Muhammad Asif Nawaz Haneef Ur Rehman Zainab Bibi Afsheen Aman Shah Ali Ul Qader |
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Institution: | The Karachi Institute of Biotechnology and Genetic Engineering (KIBGE), University of Karachi, Karachi 75270, Pakistan |
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Abstract: | Maltase from Bacillus licheniformis KIBGE-IB4 was immobilized within calcium alginate beads using entrapment technique. Immobilized maltase showed maximum immobilization yield with 4% sodium alginate and 0.2 M calcium chloride within 90.0 min of curing time. Entrapment increases the enzyme–substrate reaction time and temperature from 5.0 to 10.0 min and 45 °C to 50 °C, respectively as compared to its free counterpart. However, pH optima remained same for maltose hydrolysis. Diffusional limitation of substrate (maltose) caused a declined in Vmax of immobilized enzyme from 8411.0 to 4919.0 U ml?1 min?1 whereas, Km apparently increased from 1.71 to 3.17 mM ml?1. Immobilization also increased the stability of free maltase against a broad temperature range and enzyme retained 45% and 32% activity at 55 °C and 60 °C, respectively after 90.0 min. Immobilized enzyme also exhibited recycling efficiency more than six cycles and retained 17% of its initial activity even after 6th cycles. Immobilized enzyme showed relatively better storage stability at 4 °C and 30 °C after 60.0 days as compared to free enzyme. |
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Keywords: | Maltase Biodegradation Immobilization Calcium alginate beads Thermal stability Enzyme activity |
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