Thermostable β-galactosidase from Escherichia coli transformant containing theenzyme gene from Pyrococcus woesei was immobilized on alginate gel.The benefits of using whole bacterial cells not only exclude expensive, laborious proteinisolation and purification but also stabilize enzymes by cytosol components. Increase inproductivity of enzyme can be achieved by cells permeabilization. To increase permeability ofcytoplasmic membrane and cell wall ethanol solutions were used.The highest β-galactosidase activity was achieved when cells were permeabilized with 40%(v/v) ethanol. The rate of o-nitrophenyl-β-D-galactopyranoside (GalβoNp) hydrolysis catalyzedby free lyophilized cells was about 43% higher than that for the cells entrapped in calciumalginate gel. Recombinant Escherichia coli cells entrapped in calcium alginate were exhibitedmaximal activity at pH 5.4 and temperature 98°C. The enzymatic activity of immobilized cellsincubated 1 h at pH 5.4 in presence of 90 mM Ca2+ was very stable at temperatures below90°C.In conclusion, our research suggest that extremely thermophilic archaea Pyrococcus woeseiis a good source of β-galactosidase which can be used for production low-lactose milk anddairy products.
Authors
Additional information
- Category
- Publikacja monograficzna
- Type
- rozdział, artykuł w książce - dziele zbiorowym /podręczniku w języku o zasięgu międzynarodowym
- Language
- angielski
- Publication year
- 2012
