Immobilization of the α-amylase of Bacillus amyloliquifaciens TSWK1-1 for the improved biocatalytic properties and solvent tolerance

Abstract

The α-amylase of Bacillus amyloliquifaciens TSWK1-1 (GenBank Number, GQ121033) was immobilized by various methods, including ionic binding with DEAE cellulose, covalent coupling with gelatin and entrapment in polyacrylamide and agar. The immobilization of the purified enzyme was most effective with the DEAE cellulose followed by gelatin, agar and polyacrylamide. The K m increased, while V max decreased upon immobilization on various supports. The temperature and pH profiles broadened, while thermostability and pH stability enhanced after immobilization. The immobilized enzyme exhibited greater activity in various non-ionic surfactants, such as Tween-20, Tween-80 and Triton X-100 and ionic surfactant, SDS. Similarly, the enhanced stability of the immobilized α-amylase in various organic solvents was among the attractive features of the study. The reusability of the immobilized enzyme in terms of operational stability was assessed. The DEAE cellulose immobilized α-amylase retained its initial activity even after 20 consequent cycles. The DEAE cellulose immobilized enzyme hydrolyzed starch with 27 % of efficiency. In summary, the immobilization of B. amyloliquifaciens TSWK1-1 α-amylase with DEAE cellulose appeared most suitable for the improved biocatalytic properties and stability.

Analysis of α-amylase inhibitor from corni fructus by coupling magnetic cross-linked enzyme aggregates of α-amylase with HPLC–MS

“…5a, the optimal screening efficiency was achieved at pH 7.0. The optimum pH in screening procedure was coincidence with the report of free α-amylase [30].…”

Immobilization of α‐amylase on reactive modified fiber and its application for continuous starch hydrolysis in a packed bed bioreactor

“…The enzyme α ‐amylase has been immobilized by several methods, namely adsorption , entrapment , cross linking , and covalent binding . Among these, covalent binding is very effective in retaining the enzyme activity and provides a maximum rigidity and also prevents enzyme from unfolding upon heating or in the presence of a denaturant .…”

Enzyme immobilization onto renewable polymeric matrixes: Past, present, and future trends

“…According to Ewadh and Al‐Khafaji, the immobilization of enzymes onto gelatin primarily occurs via crosslinking between the free amino groups of the carrier and the enzyme molecule with crosslinking agents, which form a covalent bond. Kikani et al ., for instance, studied the covalent coupling of α‐amylase from Bacillus amyloliquifaciens TSWK1‐1 with gelatin, using glutaraldehyde as a crosslinker. The authors observed that the thermal and pH stabilities were significantly increased after immobilization.…”