Modification of chitosan-bead support materials with l-lysine and l-asparagine for α-amylase immobilization

Abstract

Maltose syrups have got wide-range utilizations in a variety of applications from bakery to drug-development. α-Amylases are among the most widely utilized industrial enzymes due to their high specificity in production of maltose syrup from starch. However, enzymes are not stable in ex vivo conditions towards alteration in pH, temperature, and such other parameters as high salt concentrations and impurities, where immobilization is required to advance the stability of the enzyme with which approach the requirement of isolation of the enzyme from media is eliminated as well. In this study, Termamyl α-amylase was immobilized on the none-modified chitosan beads (NMCB), L-lysine-modified chitosan beads (LMCB), and L-asparagine-modified chitosan beads (AMCB) to assess effects of the support material on optimum conditions and kinetic parameters of the α-amylase activity in production of maltose from starch. Immobilization on NMCB, LMCB, and AMCB puts a strong influence on optimum pH, optimum temperature, stability, and kinetic parameters of α-amylase. Modification of chitosan beads with L-lysine and L-asparagine dramatically altered the overall immobilization yield, and enzyme's response to pH and temperature variations and the kinetic parameters. AMCB provided the best immobilization yield (49%), while LMCB only improved the yield by 2% from 22 to 24%.

Enzymatic hydrolysis of starch into sugars is influenced by microgel assembly

“…Although high immobilization rates are counted, not all enzymes are available for process of starch breaking. The immobilization efficiencies achieved with IP and IPG beads were higher than those of Yazgan et al [26] , which reported 75.7% efficiency of commercial α -amylase Termamyl® immobilized on chitosan beads. Sharma et al [27] reported α -amylase from A. oryzae was successfully immobilized in calcium agar beads with a high immobilization efficiency of 80%.…”

“…Sharma et al [27] reported α -amylase from A. oryzae was successfully immobilized in calcium agar beads with a high immobilization efficiency of 80%. However, the overall active immobilization in the IP support of 17.18% was lower than the 24% reported by Yazgan et al [26] . The lower active immobilized enzyme in the support may have resulted in the lower overall immobilization rate, even with a high efficiency of immobilization.…”

“…Therefore, in three cycles of reuse, enzymes remained active and bound to the support, efficiently performing the conversion of starch into reducing sugars. In the work of Yazgan et al [26] , commercial α -amylase Termamyl® immobilized on chitosan beads was reused for 10 cycles and showed a reduction of activity from 100% in the first cycle to 50% in the final cycle. In the work of Sharma et al [27] , immobilized enzymes were reused for seven cycles and the results showed reusability was highly dependent on the use of calcium chloride.…”

Enhanced wound repair ability of arginine-chitosan nanocomposite membrane through the antimicrobial peptides-loaded polydopamine-modified graphene oxide

“…To increase the cytocompatibility of CS materials, many experimental and theoretical studies have been used to modifying the CS. Particularly, in recent year, the introduction of amino acid moieties to the CS generates some interesting synergistic characteristics for expanding the application scope of CS, such as l-asparagine, l-arginine or l-lysine [ 11 – 13 ]. Arginine (Arg) is considered as one important amino acids in young mammals, and it can regulates cell division, immune function, and hormone release [ 14 , 15 ].…”

Enhanced wound repair ability of arginine-chitosan nanocomposite membrane through the antimicrobial peptides-loaded dopmine-modified graphene oxide

“…To increase the cytocompatibility of CS materials,many experimental and theoretical studies have been used to modifying the CS. Particularly, in recent year, the introduction of amino acid moieties to the CS generates some interesting synergistic characteristics for expanding the application scope of CS, such as l-asparagine, l-arginine or l-lysine [12][13][14] . L-Arginine (Arg), as the crucial functional components of cell-penetrating peptides, has aroused general concern 15 .…”