title: Recombinant microbial systems for improved β-galactosidase production and biotechnological applications.
abstract: β-Galactosidases (EC 3.2.1.23) constitute a large family of proteins that are known to catalyze both hydrolytic and transgalactosylation reactions. The hydrolytic activity has been applied in the food industry for decades for reducing the lactose content in milk, while the transgalactosylation activity has been used to synthesize galacto-oligosaccharides and galactose containing chemicals in recent years. The main focus of this review is on the expression and production of Aspergillus niger, Kluyveromyces lactis and bacterial β-galactosidases in different microbial hosts. Furthermore, emphasis is given on the reported applications of the recombinant enzymes. Current developments on novel β-galactosidases, derived from newly identified microbial sources or by protein engineering means, together with the use of efficient recombinant microbial production systems are converting this enzyme into a relevant synthetic tool. Thermostable β-galactosidases (cold-adapted or thermophilic) in addition to the growing market for functional foods will likely redouble its industrial interest.
authors.affiliation: IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
authors.forename: Carla
authors.initials: C
authors.lastname: Oliveira
authors.forename: Pedro M R
authors.initials: PM
authors.lastname: Guimarães
authors.forename: Lucília
authors.initials: L
authors.lastname: Domingues
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics; D001709:Biotechnology / Q000379:methods*; D015202:Protein Engineering / Q000379:methods*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics; D001616:beta-Galactosidase / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D011994:Recombinant Proteins; D001616:beta-Galactosidase