SOLUBLE EXPRESSION OF BACILLUS LICHENIFORMIS ATCC 27811 α-AMYLASE AND CHARACHTERIZATION OF PURIFIED RECOMBINANT ENZYME Authors: A. Muazzam, 2, B. Malik, N. Rashid, S. Irshad, M. Fatima Journal: Journal of Animal and Plant Sciences (JAPS) ISSN: 1018-7081 (Print), 2309-8694 (Online) Volume: 29 Issue: 1 Pages: 99-108 Year: 2019 DOI: N/A URL: https://doi.org/N/A Publisher: Pakistan Agricultural Scientists Forum Abstract:

Alpha amylase (α-amylase) from Bacillus licheniformis shows great role in starch hydrolysis for industrial application due to its thermostability, long half-life and specificity. However, it is difficult to produce this enzyme in large quantities because of formation of inclusion bodies, but lowering the temperature to 18 °C leads to a soluble expression of protein. This also highlighted the efficacy of Escherichia coli as one of the best host for secretion of recombinant proteins. A further study to find an approach for a soluble expression of α-amylase was conducted here, using pET-22b(+)  as an expression vector and temperature optimization. Purified monomeric enzyme displayed a specific activity of 584.61 U/mg at 37 °C and a molecular mass of 52 kDa. Purification fold of recombinant α-amylase was 2.04 times in comparison to crude amylase extract.  Relative activity of enzymewas remarkably enhanced by Ca+2 but strongly impeded by Cu2+ and Na+1, highlighted the significance of Ca+2 as a cofactor for optimal amylase activity.

Keywords: Hydrolysis, Soluble, Thermostable, Industrial