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.

Immobilization of β-d-galactosidase from Kluyveromyces lactis on functionalized silicon dioxide nanoparticles: Characterization and lactose hydrolysis

“…Treatment of cheese whey with BGAL increases its fermentability to ethanol, helping to reduce the pollution caused by large volumes of this by-product released into the environment [11]. While whey represents a challenge in terms of down-stream processing, it has recently been utilized for ethanol, exopolysaccharide and single cell protein production by employing BGAL [12]. Thus an enzyme assisted technology is required which may convert whey lactose into value added products and address bioremediation.…”

Application of Coastal and Marine Ecological Classification Standard to organize island ecosystem: the Abu Musa Island, Persian Gulf case study

“…Based on Table 5, there was no significant difference among all fermentation periods on both isolates and optimal production time could not be determined with variations of up to 10 days of production time. The enzyme activity obtained in this study was much lower compared to the activity of the enzyme β-galactosidase derived from Aspergillus niger and Kluyveromyces lactis (Oliveira et al 2011). Meanwhile, the specific activity of the enzyme could be used as a measurement of the purity of the isolated enzyme.…”

The Role of Extremophilic Microorganisms and their Bioproducts in Food Processing and Production

“…However, there are some established applications for psychrophilic enzymes, as well as potential applications, which are listed by Cavicchioli and Siddiqui (2006). Processing of milk and dairy products is one area where cold-adapted ␤-galactosidases may find wide application (for a review of ␤-galactosidase applications, production, and sources, see Oliveira et al, 2011). Due to the inability of adults to synthesize intestinal lactase, lactose intolerance is widespread and causes digestive discomfort due to fermentation of lactose by the intestinal microflora.…”