Coexpression of ß-D-galactosidase and L-arabinose isomerase in the production of D-tagatose: a functional sweetener.
J Agric Food Chem
; 62(11): 2412-7, 2014 Mar 19.
Article
en En
| MEDLINE
| ID: mdl-24568679
ABSTRACT
The functional sweetener, d-tagatose, is commonly transformed from galactose by l-arabinose isomerase. To make use of a much cheaper starting material, lactose, hydrolization, and isomerization are required to take place collaboratively. Therefore, a single-step method involving ß-d-galactosidase was explored for d-tagatose production. The two vital genes, ß-d-galactosidase gene (lacZ) and l-arabinose isomerase mutant gene (araA') were extracted separately from Escherichia coli strains and incorporated into E. coli simultaneously. This gave us E. coli-ZY, a recombinant producing strain capable of coexpressing the two key enzymes. The resulted cells exhibited maximum d-tagatose producing activity at 34 °C and pH 6.5 and in the presence of borate, 10 mM Fe(2+), and 1 mM Mn(2+). Further monitoring showed that the recombinant cells could hydrolyze more than 95% lactose and convert 43% d-galactose into d-tagatose. This research has verified the feasibility of single-step d-tagatose fermentation, thereby laying down the foundation for industrial usage of lactose.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Contexto en salud:
3_ND
Problema de salud:
3_neglected_diseases
/
3_zoonosis
Asunto principal:
Edulcorantes
/
Beta-Galactosidasa
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Isomerasas Aldosa-Cetosa
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Proteínas de Escherichia coli
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Escherichia coli
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Hexosas
/
Lactosa
Idioma:
En
Revista:
J Agric Food Chem
Año:
2014
Tipo del documento:
Article