• Food Science and Biotechnology
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• v.17 no.5
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• pp.1115-1118
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• 2008

${\alpha}$-Galactosidase gene (aga) from Leuconostoc mesenteroides SY1 was expressed in a heterologous host, Lactobacillus brevis 2.14 using an Escherichia coli-Leuconostoc shuttle vector, pSJE. pSJEaga (pSJE carrying aga) was introduced into Lactobacillus brevis 2.14 by electroporation and transformation efficiency was $1.1{\times}10^3$ per ${\mu}g$ DNA. L. brevis transformants (TFs) showed higher ${\alpha}$-galactosidase (${\alpha}$-Gal) activities than cells containing pSJE. Transcription levels of aga in L. brevis 2.14 grown on different carbon sources (1%, w/v) were examined by slot blot analysis. Aga transcript levels and ${\alpha}$-Gal activities were higher in cells grown on melibiose, raffinose, and galactose than cells on glucose, sucrose, and fructose. Western blot result showed that L. brevis 2.14 harboring pSJEaga produced much more ${\alpha}$-Gal when grown on melibiose than on glucose.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.6
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• pp.901-906
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• 2013

We examined the availability of the lacZ gene (${\beta}$-galactosidase gene) as a reporter of foreign gene transfer in the cysts of Artemia franciscana (A. franciscana) to conduct a risk assessment of living genetically modified organisms (LMOs) in the marine ecosystem. The LacZ gene was transferred to decapsulated cysts by particle bombardment, and its insertion and expression were assessed by means of polymerase chain reaction (PCR) and X-gal staining. X-gal staining indicated lacZ expression in all A. franciscana examined (including the control group), which exhibited not only negative but also positive PCR amplification. Endogenous ${\beta}$-galactosidase is highly active in the whole body of A. franciscana during all stages of the life cycle. Thus, the lacZ gene is unsuitable as a reporter for foreign gene transfer in A. franciscana cysts, because it is difficult to discriminate between exogenous and endogenous ${\beta}$-galactosidase activity.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.5
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• pp.337-340
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• 2001

A galactooligosaccharide(GalOS)-producing yeast, OE-20 was selected from forty seven strains of yeast growing in Korean traditional Meju (cooked soybean) and the yeast was tentatively identified as Kluyveromyces maxianus var lactis by its morphology and fermentation profile. A maximum yield of 25.1%(w/w) GalOS, which corresponds to 25.1 g of GalOS per liter, was obtained from the reaction of 100 g per liter of lactose solution at 3$0^{\circ}C$, pH 7.0 for 18 h with an intracellular crude $\beta$-galactosidase. Glucose and galactosidase were found to inhibit GalOS formation. The GalOS that were purified by active carbon and celite 545 column chromatography were supplemented in MRS media and a stimulated growth was observed of some intestinal bacteria. In particular the growth rate of Bifidobacterium infantis in the GalOS containing MRS broth increased up to 12.5% compared to that of the MRS-glucose broth during a 48h incubation period.

• Microbiology and Biotechnology Letters
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• v.24 no.1
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• pp.72-76
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• 1996

To investigate the expression efficiency of new transfer vector of Bombyx mori nuclear polyhedrosis virus (BmNPV), Escherichia coli lacZ gene was inserted into new transfer vector pBmKSK1, under the control of polyhedrin promoter and expressed in BmN-4 cells and larvae of silkworm, Bombyx mori. The recombinant virus containing lacZ gene was isolated from BmN-4 cells coinfected with transfer vectro pBmKSK1-LacZ and wild type BmNPV genome, and analysed by Southern blotting. The expression of ${\beta}$-galactosidase was characterized by SDS-PAGE, Western blotting and ${\beta}$-galactosidase activity assay. The results showed that the level of expression in silkworm larvae was higher than that of BmN-4 cells.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.5
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• pp.611-616
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• 1993

This study was carried out to investigate change in the polygalacturonase and ${\beta}-galactosidase$ activities, pectins, cell wall structure of persimmon fruit during ripening and softening. Polygalacturonase and ${\beta}-galactosidase$ activities were not detected at turning stage. However polygalacturonase activities of mature and soft persimmon fruits were 55.01 and 206.70units/100g-fresh weight(fr. wt.), respectively. ${\beta}-Galactosidase$ activities of mature and soft persimmon fruits were 21.79 and 380.23unit/100g-fr. wt. respectively. The contents of total and insoluble pectins increased during maturation but decreased during softening. The content of water-soluble pectin increased during maturation and softening. The intercellular space was in larged during ripening, and middle lamella was degraded in mature persimmon fruit, and the cells of soft persimmon fruit were separated each other.

• Journal of Microbiology and Biotechnology
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• v.15 no.3
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• pp.678-682
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• 2005

The promoter region of a carbon starvation gene isolated from Pseudomonas putida was cloned and analyzed for its potential use for in situ bioremediation and bioprocessing. We constructed a recombinant plasmid pMKD101 by cloning the 0.65 kb promoter region of the gene into the promoter proving vector, pMK301, which contains the lacZ for ${\beta}$-galactosidase activity as a reporter gene. pMKD101 was transformed into the wild-type P. putida MK1, resulting in P. putida RPD101, and analyzed for ${\beta}$-galactosidase activity under different culture conditions. When RPD101 was grown on the minimal medium plus $0.1\%$ glucose as a sole carbon source in batch cultures, ${\beta}$-galactosidase activity was found to be 3.2-fold higher during the stationary phase than during the exponential phase. In chemostat cultures, ${\beta}$-galactosidase activity was found to be 3.1-fold higher at the minimal growth rate (dilution rate=$0.05\;h^{-1}$) than at the maximal growth rate (dilution rate=$0.173;h^{-1}$). The results suggest that a carbon starvation promoter can be utilized to maximize the expression of a desired gene under nutrient limitation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.14 no.2
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• pp.157-163
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• 1985

Various cell wall polysaccharides and related enzyme activities in hot pepper fruit were determined at different stages of maturity. The uronic acid content of cell walls decreased between immature green and turning stage fruit and then increased by red ripe stage. In contrast, cellulose content of cell walls changed only a little during ripening. Total neutal sugar content of cell wall material decreased 50% and galactose content of the walls decreased about 80% by the turning stage. Polygalacturonase and ${\beta}-galactosidase$ activities, as well as total hemicellulose from isolated cell walls of ripening hot pepper fruit were studied using gel filtration chromatography. Polygalacturonase activity was not detectable but 5 isozymes of ${\beta}-galactosidase$ were resolved. The activities of the enzymes were relatively high and gel filtration showed that they differed in molecular weight. Hemicellulose content decreased during ripening and softening. The molecular weight profiles shifted from high molecular weight to low molecular weight polymers during ripening. The changes in cell walls that may be associated with fruit softening involve the alteration of hemicellulose prior to the degradation of wall-bound uronic acid. It is suggested that the decrease in cell wall galactose involved changes in turnover of new cell wall components.

• Korean Journal of Food Science and Technology
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• v.20 no.1
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• pp.79-84
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• 1988

${\alpha}$-Galactosidase from Aspergillus niger as a possible enzyme for removal of flatulence factors in soybean foods was produced the highest in 120 hours in either Czapeck-Dox liquid medium or wheat bran solid medium. The most efficient carbon and nitrogen sources in Czapeck-Dox medium were raffinose and sodium nitrate, respectively, whereas the addition of the sources showed negative effects in wheat bran. pH optima for enzyme activity and stability were 4.0-5.0 and 3.5-6.5, respectively, and optimum temperature for stability was $40-50^{\circ}C$. Upon reaction on p-nitrophenyl-${\alpha}$-D-galactoside, Michaelis constant was 0.42 mM and maximum velocity was 152 ${\mu}moles$ substrate/minute/kg solid medium. Mercuric chloride acted as a strong noncompetitive inhibitor and p-chloromercuribenzoate, even in low concentration, acted as a competitive inhibitor. Crude ${\alpha}$-galactosidase hydrolyzed raffinose and stachyose completely, giving spots of monosaccharides only on thin-layer chromatogram.

• Analytical Science and Technology
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• v.5 no.4
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• pp.465-469
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• 1992

An analytical procedure is presented for the quantitative determination of lactose, glucose, and galactose in the hydrolyzate of lactose by ${\beta}$-galactosidase with high-performance liquid chromatography. An Aminex HPX-87C column at $85^{\circ}C$ and refractive index detector were used to resolve lactose, glucose, and galactose in only 12 minutes with distilled and deionized water as a mobile phase. The validity of high-performance liquid chromatography as a method for the assay of ${\beta}$-galactosidase was supported by recovery experiments and comparision of results with those by ONPG method, a spectrophotometric assay. The procedure was appropriate for determination of sugars in the enzyme reaction mixture and could by applied to analysis of ${\beta}$-galactosidase activity.

• Journal of Chest Surgery
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• v.45 no.6
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• pp.368-379
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• 2012

Background: Bioprostheses for cardiovascular surgery have limitations in their use following as calicification. ${\alpha}$-galactosidase epitope is known as a stimulant of immune response and then shows a progressing calcification. The objective of this study was to evaluate histologic characteristics and mechanical properties of decellularization and treated with ${\alpha}$-galactosidase. Materials and Methods: Bovine pericardial tissues were allocated into three groups: fixation only with glutaraldehyde, decellularization with sodium dodesyl sulfate and decellularization plus treatment with ${\alpha}$-galactosidase. We confirmed immunohistological characteristics and mechanical properties as fatigue test, permeability test, compliance test, tensile strength (strain) test and thermal stability test. Results: Decellularization and elimination of ${\alpha}$-gal were confirmed through immunohistologic findings. Decellularization had decreased mechanical properties compared to fixation only group in permeability (before fatigue test p=0.02, after fatigue test p=0.034), compliance (after fatigue test p=0.041), and tensile strength test (p=0.00). The group of decellularization plus treatment with ${\alpha}$-galactosidase had less desirable mechanical properties than the group of decellularization in concerns of permeability (before fatigue test p=0.043) and strain test (p=0.001). Conclusion: Favorable decellularization and elimination of ${\alpha}$-gal were obtained in this study through immunohistologic findings. However, those treatment including decellularization and elimination of ${\alpha}$-gal implied the decreased mechanical properties in specific ways. We need more study to complete appropriate bioprosthesis with decellularization and elimination of ${\alpha}$-gal including favorable mechanical properties too.