Immobilization of xylan-degrading enzymes from Melanocarpus albomyces IIS 68 on the smart polymer Eudragit L-100

Abstract

Xylanase of Melanocarpus albomyces IIS 68 was immobilized on Eudragit L-100. The latter is a copolymer of methacrylic acid and methyl methacrylate and is a pH-sensitive smart polymer. The immobilization was carried out by gentle adsorption and an immobilization efficiency of 0.82 was obtained. The enzyme did not leach off the polymer even in the presence of 1 M NaCl and 50% ethylene glycol. The K(m) of the enzyme changed from 5.9 mg ml(-1) to 9.1 mg ml(-1) upon immobilization. The V(max) of the immobilized enzyme showed an increase from 90.9 micro mol ml(-1) min(-1) (for the free enzyme) to 111.1 micro mol ml(-1) min(-1). The immobilized enzyme could be reused up to ten times without impairment of the xylanolytic activity. The immobilized enzyme was also evaluated for its application in pre-bleaching of eucalyptus kraft pulp.

Immobilization of xylanase purified from Bacillus pumilus VLK-1 and its application in enrichment of orange and grape juices

“…The residual activity of immobilized enzyme was more than 90 %, 85 % and 58 % after four, five and ten reaction cycles, respectively. The decrease in enzyme activity during repeated use with varying extent has been reported by several researchers (Bhushan et al 2013;Roy et al 2003). A decline in activity during reuse might occur due to enzyme inactivation as suggested earlier (Nagar et al 2012b).…”

“…Further, since enzyme molecules are on the surface, contact with large substrates is possible as required in case of xylanase. Immobilization of xylanase has been reported on various supports including polymethyl methacrylate nanofibers membrane (Kumar et al 2009), Eudragit L-100 (Roy et al 2003), silica (Kang et al 2002;Sharma et al 2012), chitin, HP-20 and gelatin (Kapoor and Kuhad 2007); glass beads (Kumar et al 2009), chitosan beads (Jingmin et al 2002), alginate beads (Bhushan et al 2013) and Eudragit S-100 (Edward et al 2002;Gawande and Kamat 1998). However, only a few papers have reported the use of immobilized xylanase in enhancing the yield and clarification of fruit juices (Bhushan et al 2013;Sharma et al 2012).…”

Immobilization of Xylan-Degrading Enzymes from Scytalidium thermophilum on Eudragit L-100

“…It binds non-covalently to proteins. It was selected for immobilization of xylanase in this study because of its pH-sensitive properties (Roy et al 2003). It is soluble above pH 6.0 and insoluble below pH 4.0.…”

“…Eudragit L-100 solution was prepared as described by Roy et al (2003). Eudragit L-100 (1 g) was dissolved in 40 ml distilled water by adding 3 M NaOH dropwise until the pH rose to 11.0.…”

“…Screening of diverse microbial sources for xylanases with the desired characteristics and immobilization of known xylanases for enhancing thermal stability and imparting reusability have been an area of extensive research for these reasons (Gawande & Kamat 1998a, b;Roy et al 2003).…”