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Thermostable α‐amylase immobilization: Enhanced stability and performance for starch biocatalysis
Author(s) -
Kumar Gudi Satheesh,
Rather Gulam Mohmad,
Gurramkonda Chandrasekhar,
Reddy Bontha Rajasekhar
Publication year - 2015
Publication title -
biotechnology and applied biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.468
H-Index - 70
eISSN - 1470-8744
pISSN - 0885-4513
DOI - 10.1002/bab.1350
Subject(s) - immobilized enzyme , hydrolysis , amylase , starch , chemistry , biocatalysis , substrate (aquarium) , chromatography , enzyme , chemical engineering , catalysis , organic chemistry , biology , reaction mechanism , ecology , engineering
Abstract The uses of thermostable starch hydrolytic biocatalysts are steadily increasing for the industrial application because of their obvious need for biocatalytic performance at elevated temperatures. The starch liquefaction and saccharification can be carried out simultaneously by the use of thermostable starch hydrolytic biocatalysts, thus minimizing the unit operations, time, and efforts. The cost factor hampers the industrialization of expensive soluble (free) enzymes for biocatalytic applications and the immobilization of enzymes offers promising alternative to the hurdle. The present investigation was aimed for immobilization of thermostable α‐amylase using calcium alginate, and statistical optimization studies were carried out for enhanced biocatalytic performance. Initially, one‐parameter at a time optimization studies were carried out for identification of significant factors influencing the immobilization. Furthermore, a statistical approach, response surface methodology, was applied for immobilization of α‐amylase. The immobilized α‐amylase in alginate microbeads showed enhanced stability to temperature and reusable property for up to seven cycles (with the retention of 50% initial activity). Finally, the kinetic behavior of free and immobilized enzyme showed the K m value of 1.2% and 2.6% (w/v) and V max of 1,020 and 1,030 U, respectively. Fifty percent reduction in affinity of the immobilized enzyme toward substrate was compensated by its longer stability.