Highly Efficient Method Towards In Situ Immobilization of Invertase Using Cryogelation

Abstract

A novel method was developed for the immobilization of Saccharomyces cerevisiae invertase within supermacroporous polyacrylamide cryogel and was used to produce invert sugar. First, the cross-linking of invertase with soluble polyglutaraldehyde (PGA) was carried out prior to immobilization in order to increase the bulkiness of invertase and thus preventing the leakage of the cross-linked enzyme after immobilization by entrapment. And then, in situ immobilization of PGA cross-linked invertase within cryogel synthesis was achieved by free radical polymerization in semi-frozen state. The method resulted in 100 % immobilization and 74 % activity yields. The immobilized invertase retained all the initial activity for 30 days and 30 batch reactions. Immobilization had no effect on optimum temperature and it was 60 °C for both free and immobilized enzyme. However, optimum pH was affected upon immobilization. Optimum pH values for free and immobilized enzyme were 4.5 and 5.0, respectively. The immobilized enzyme was more stable than the free enzyme at high pH and temperatures. The kinetic parameters for free and immobilized invertase were also determined. The newly developed method is simple yet effective and could be used for the immobilization of some other enzymes and microorganisms.

Poly(acrylamide/vinylsulfonic acid) hydrogel for invertase immobilization

“…As a result, the optimum pH value changed (Toppare, Erginer, Alkan, & Bakir, 2000). Similar results were found in invertase immobilization studies (Andjelkovi c et al, 2015;Bahar, 2014;Olcer, Ozmen, Sahin, Yilmaz, & Tanriseven, 2013) as well as in our studies (the optimum pH values as 5.5, 4.5, 6.0, 6.0, and 5.5 for composite hydrogels; poly(acrylamide)-sepiolite-invertase, poly(acrylamide/acrylic acid)-sepiolite-invertase, poly(acrylamide/ itaconic acid)-sepiolite-invertase, poly(acrylamide/maleic acid)-sepiolite-invertase and for copolymeric hydrogels poly(methacrylamide/ maleic acid)-invertase, respectively (Öztop et al, 2009; Öztop et al, 2010; Öztop et al, 2018).…”

Industrial Approach to Invertase Production from Fruit Waste for Enhanced Efficiency and Conservation

“… 7 In another study, however, a method was developed to trap S. cerevisiae invertase within a supermacroporous polyacrylamide cryogel. 41 The process resulted in a 74% activity yield. The immobilized invertase retained all of its initial activity for 30 days and 30 batch reactions.…”

“…Immobilization did not affect the optimum temperature, which remained at 60 °C for both the free enzyme and the immobilized enzyme. However, the immobilized enzyme demonstrated greater stability than the free enzyme under conditions of high pH and temperature …”

“…In another study, however, a method was developed to trap S. cerevisiae invertase within a supermacroporous polyacrylamide cryogel . The process resulted in a 74% activity yield.…”

“…However, the immobilized enzyme demonstrated greater stability than the free enzyme under conditions of high pH and temperature. 41 Another study on invertase from S. cerevisiae showed that the thermal stability of the enzyme was investigated for three different forms: immobilized invertase on Celite, immobilized invertase on polyacrylamide, and free invertase. 38 The results indicated that the order of decreasing stability was immobilized on Celite, immobilized on polyacrylamide, and soluble invertase.…”