ß-Galactosidase Research Papers - Academia.edu (original) (raw)

Immobilization of β-GAL could represent an important driving force for the development of lactose hydrolysis and galacto-oligosaccharides (GOS) synthesis technology. The enzymatic hydrolysis of lactose is one of the most important biotechnological processes in the food industry. It is carried out by β-d-galactosidase (also named lactase, EC 3.2.1.108), an enzyme used in several applications for hydrolysis of lactose from milk or whey. The main benefit of lactose-hydrolyzed products is that they overcome lactose intolerance, present in more than half of population of the world. Manufacture of lactose-free milk and dairy products is important to allow consumption of such foods for people (especially children) with intestinal lactase deficiency, resulting in lactose intolerance (Panesar et al., 2006). Another important result of the lactose hydrolysis process is the increased sweetening power and solubility of the obtained monosaccharides, which can generate new applications,

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- Biocatalysis, ß-Galactosidase, Galactooligosaccharides

Biotechnology has almost unlimited potential to change our lives in very exciting ways. Many of the chemical reactions that produce these products can be fully optimized by performing them at extremes of temperature, pressure, salinity, and pH for efficient and cost-effective outcomes. Fortunately, there are many organisms (extremophiles) that thrive in extreme environments found in nature and offer an excellent source of replacement enzymes in lieu of mesophilic ones currently used in these processes. In this review, I discuss the current uses and some potential new applications of extremophiles and their products, including enzymes, in biotechnology.

- by James Coker
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- Extremophiles, RNA polymerase, Carotenoids, Cellulase

We examined variants of an especially cold-active beta-galactosidase (BgaS) to better understand features affecting enzyme activity at temperature extremes. We targeted locations corresponding to a region in the LacZ enzyme previously shown to increase activity and decrease thermostability. Changes in this region of BgaS consistently caused the elimination or reduction of activity. A gene (bgaS3) encoding a loss of function variant was subjected to random mutagenesis to restore activity and discover potential interactions important in cold activity. Gene sequences from the resulting library indicated that only two amino acid alterations, E229D and V405A, were required to restore activity. Genes with combinations of these mutations were constructed and their enzymes purified. Enzymes with the E229D/V405A/G803D alterations (BgaS6), or E229D/V405A (BgaS7) had similar thermal optima and thermostabilities as BgaS. BgaS7, however, showed a 2.5-fold increase in catalytic activity at 15 degrees C and hydrolyzed 80% of lactose in skim milk in less than half the time of BgaS at 2.5 degrees C. Computer-generated models predicted that the substitutions at positions 229 and 405 yielded fewer contacts at the enzyme's activating interface. Results from regional saturation mutagenesis supported this hypothesis and suggested that not easily predicted, subtle, cooperative intramolecular interactions contributed to thermal adaptation.

- by James Coker
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- Enzymology, Extremophiles, Enzymes, Microbial Enzymes

-galactosidase producing BPTK4 was isolated from the diary industry effluent in Chennai.
Biochemical tests and 16S rRNA sequencing was used for the confirmation of the strain BPTK4 as Bacillus
subtilis. The strain BPTK4 was assessed for its probiotic nature using antibiotic markers. The characterization
of the enzyme and optimization of the production medium were carried out for the maximum production and
activity of -galactosidase. Maximum production of enzyme was obtained when the medium was incubated for
48 hours at the temperature of 35°C and maintained at pH 7. Various carbon (1% m/v) and nitrogen (0.015% m/v)
sources, metal ions (1mM) and natural substrates (1% m/v) were introduced into the medium and their effects
were studied. Xylose, Yeast extract, Mg2+ ion, Mn2+ ion and wheat bran increased the production of enzyme.
The enzyme was purified by ion exchange chromatography using DEAE sephacel column and it was
characterized for stability based on temperature and pH. The enzyme showed highest activity at the temperature
of 55°C (0.350 U/ml) and at pH 7 (0.294 U/ml). The enzyme retained 100% of its activity at 45°C and retained 90%
of its activity at pH 7.

- by Ravi Kumar
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- Enzymes, Microbial Enzymes, ß-Galactosidase, Enzyme production

The lysosomal enzymes cathepsin D (E.C. 3.4.23.5), alpha-glucosidase (E.C. 3.2.1.20) and ß-galactosidase (E.C. 3.2.1.23), potentially involved in the breakdown of the peptide component and the disaccharide units of basement membrane glycoproteins, were studied in the kidney cortex and liver of normal (n=8) and streptozotocin-diabetic (n=7) mice. In the liver of diabetic mice, as compared to controls, an increase was found for the total activity (measured in frozen-thawed homogenates) of cathepsin D (+135%, P<0.01) and ß-galactosidase (+32%, P<0.05). In the kidney a decrease was observed for both the free activity (measured in 12,000 g supernatant) and the total activity of these two enzymes (cathepsin D: -62% and -24%; ß-galactosidase: -29% and -23%; P<0.05 in all instances). Alpha-Glucosidase did not show significant changes in either tissues. Total protein content of the two organs did not change significantly with diabetes and therefore cannot account for the enzyme alterations observed. These data indicate that the response of kidney to diabetes is opposite to that of liver (decrease versus increase in catabolic enzymes), and suggest decreased degradation of basement membrane in some tissues in diabetes, which may contribute to the thickening of basement membrane and therefore to the development of microangiopathy.

- by Francesco Belfiore
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- Kidney, cathepsin D, Diabetic Mice, Alpha-Glucosidase