Biochemical characterization, partial purification, and production of an intracellular beta-galactosidase from Streptococcus thermophilus grown in whey. European Journal of Experimental Biology, Vol. 3(2), April 2013, pp.242-251. (original) (raw)
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European Journal of Experimental Biology
Beta-galactosidase is one of the important commercial enzymes having several applications in food and pharmaceutical industry. In dairy industry, β-galactosidase has been used to prevent crystallization of lactose, to improve sweetness, to increase the solubility of the milk product. Moreover, it has been used to produce low lactose containing food products for low lactose tolerance people and for the utilization of whey, which would otherwise be an environmental pollutant. Based on its importance, the present research was aimed to isolate and purify βgalactosidase from Streptococcus thermophilus by fermentation process. The enzyme was purified by ammonium sulphate precipitation, dialysis, gel filtration chromatography using Sephadex G-100, and SDS-PAGE and some properties of the purified enzyme like pH, temperature optima and kinetic parameters were determined. Isolate A5 showed highest productivity of 7.76 U/ml with a protein content of 67 µg/mL, pH and temperature optima at pH 7.2 and 40 º C. The apparent V max and K m values were found to be 2.8 IU/mL and 3.05 mM, respectively. Specific activity and fold purification of beta-galactosidase was found to be 119.38 & 1.13, respectively. These characteristics of isolated β-galactosidase showed that it could be a promising candidate for various industrial as well as biotechnological applications.
Biochemical and thermal properties of β-galactosidase enzymes produced by artisanal yoghurt cultures
Food Chemistry, 2010
b-Galactosidases, produced by pure and mixed cultures of Streptococcus thermophilus 95/2 (St 95/2) and Lactobacillus delbrueckii ssp bulgaricus 77 (Lb 77) isolated from the Toros mountain region of Turkey, were characterised with respect to their biochemical and thermal properties. Optimum pH and temperature for maximum activity were determined and these enzymes were stable in the pH range 7-9 and in the temperature range 20-37°C, retaining 80-90% of their initial activities. The inactivation energies of bgalactosidase from Lb 77, St 95/2 and mixed culture (Lb 77 and St 95/2) were 51.3, 44.0 and 48.3 kcal mol À1 , respectively. Moreover, thermodynamic (DG, DS, DH) and kinetic constants (K m and V max) were determined and effects of metal ions were investigated. As a result, these enzymes could be considered as potential candidates for lactose hydrolysis of milk and milk products.
Production of β-galactosidase from streptococcus thermophilus for galactooligosaccharides synthesis
Journal of Food Science and Technology, 2014
Efficiency of different methods for disruption of Streptococcus thermophilus cells, isolated from different dairy products, to release β-galactosidase and synthesis of GOS by extracted enzyme using whey supplemented with different concentrations of lactose as a substrate was studied. Unlike most other studies on GOS synthesis which used only one method of cell disruption and only few microbial strains, we compared five different cell disruption methods and used 30 strains of S. thermophilus in order to find out the most effective method and efficient strain for production of βgalactosidase. Appreciable amount of GOS (53.45 gL −1) was synthesized at a lactose concentration of 30 %, using enzyme (10 U mL −1 of reaction medium), extracted from S. thermophilus within a very short incubation time of 5 h at a temperature of 40°C and pH 6.8. S. thermophilus is heavily employed in the preparation of fermented dairy products but this study extends the use of this organism for the production of GOS, a potential prebiotic.
Journal of Food Science and Engineering
The enzyme β-galactosidase (lactase; EC 3.2.1.23) is a commercially important enzyme due to its various applications in dairy and food industries, which are based on the β-galactosidase-catalysed hydrolysis of lactose into glucose and galactose. The objectives of this work were to identify novel and attractive sources of this industrially relevant enzyme, and to study the effect of selected growth parameters (carbon source, lactose concentration, nitrogen source, peptone concentration, initial pH and temperature) on the formation of β-galactosidase. Based on a screening of isolates from Tha Pai hot spring, Mae Hong Son Province, Thailand, strain B1.1 was selected for further studies. Strain B1.1 is a Gram-positive, rod-shaped, catalase-positive bacterium that forms endospores. Based on the sequence of the 16S rDNA determined, this isolate is most closely related to Anoxybacillus sp. and Bacillus sp., and hence the strain is designated as Bacillus sp. B1.1. β-Galactosidase was produced by this strain with lactose and peptone as carbon and nitrogen sources, respectively. Optimal enzyme production occurred at an initial culture pH of 8.5 and at 45 °C. Under these optimum culture conditions, maximal volumetric and specific β-galactosidase activity of 0.478 U mL-1 and 0.338 U mg-1 protein, respectively, were obtained after 13 h of cultivation in a medium contain 2.5% lactose, 2.0% peptone, 0.3% K 2 HPO 4 , 0.1% KH 2 PO 4 and 0.05% MgSO 4 •7H 2 O.
Periodica Polytechnica Chemical Engineering, 2016
Whey was used as a source of isolation of bacterial strains, symbolized as, IB1, IB2 and IB3, capable of synthesizing β-galactosidase. The microbe labeled as IB1 was tested to be most tolerant against pH and temperature shocks, as well as, heavy metals. Subsequently, IB1 was identified as Bacillus safensis (JUCHE 1) by genetic information. In a later exercise, it was used for β-galactosidase production using whey through fermentative route. The initial concentration of substrate, i.e., lactose in microbial growth medium was varied ranging from of 5-50 g/L. It was found that the classical Monod kinetics and substrate inhibited Monod kinetics are able to describe the microbial growth kinetics at low (5-20 g/L), and high (>20 g/L) concentration ranges of lactose in growth medium respectively. Kinetics of β-galactosidase production followed the Monod incorporated modified Luedeking-Piret model and the Monod incorporated Luedeking-Piret model with substrate inhibition in the low, and high ranges of lactose concentration in growth medium respectively.
Production of Food Grade β-Galactosidase from Artisanal Yogurt Strains
Food Biotechnology, 2010
Superior artisanal isolates of thermophilic lactic acid bacteria producing high lactic acid and β-galactosidase were isolated from traditional Turkish yogurt samples from the Toros mountain region from a highly bio-diverse environment. A full factorial statistical design, with the factors of types of strains and medium formulations under static and agitation conditions, were applied to investigate the effects on β-galactosidase and
The comparison of commercially available β-galactosidases for dairy industry : review
Research for rural development, 2017
β-Galactosidase (EC 3.2.1.23) is one of the widely used enzymes for lactose-free milk production and whey permeate treatment. Enzymes can be obtained from microorganisms, plants and animals. Nowadays, microorganisms are becoming an important source for production of commercially available enzymes, which are of great interest and offer several advantages such as easy handling and high production yield. The aim of this review was to summarize findings of research articles on the application of commercially available β-galactosidase preparates in dairy industry, to analyse and compare the most suitable β-galactosidase commercial preparates for lactose hydrolysis. The results showed that the main factor to choose an appropriate β-galactosidase for lactose hydrolysis was reaction condition. Enzymes from microorganisms contain a wide range of optimal pH from 4.0 (Penicillium simplicissimum and Aspergillus niger) to 8.5 (Bacillus subtilis). The greatest commercial potential have enzymes obtained from fungi (Aspergillus oryzae and Aspergillus niger) and yeasts (Kluyveromyces lactis and Kluyveromyces fragilis). Fungal origin enzymes are more suitable for the hydrolysis of lactose in acid whey due to its acidic pH but yeasts origin enzymes for milk and sweet whey. In the study, commercial preparates from different suppliers with the purpose to analyse their lactose hydrolysis potential and give more detailed characteristics of each preparate advantages and drawbacks were also summarized.
A STUDY ON β-GALACTOSIDASE OF LACTOBACILLUS SP FROM MILK PRODUCTS AND ITS APPLICATIONS
β-galactosidases enzyme have been used in the dairy industry for the improvement of lactose intolerance. The aim of the present study was to isolate β-galactosidase enzyme produced by isolated lactobacillus from milk and cheese. Isolated lactobacilli were cultured on MRS agar. Lactobacilli were identified by Gram staining and standard bacteriological and biochemical methods. Their ability to hydrolyze 5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside (X-Gal) and O-nitrophenyl-β-Dgalactopyranoside (ONPG) was determined. β-galactosidase enzyme activity was also detected by Sodium Dodecyl Sulphate Gel electrophoresis (SDS-PAGE) method. The colonies that produced blue green color on X-Gal plates were lactobacillus with β-galactosidase enzyme which had ONPG positive results. By adding Lactobacillus producing β-galactosidase enzyme as probiotic to dairy products, could help lactose intolerant infants.