• Korean Journal of Food Science and Technology
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• v.30 no.1
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• pp.230-236
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• 1998

We have screened total 32 herbal drugs to find the highest activity against human cariogenic enzyme, glucosyltransferase (GTase) from the extracts of Magnoliae bark. The extracts were separated into three phases, i. e. water, n-butanol and ethylacetate according to their solvent polarity. Among them, ethylacetate fraction had approximately more than 70% of total activities, and the active principle was further isolated by prep. HPLC following silicagel column chromatography to yield single compound as white powder. The chemical structure of the compound was finally elucidated to be 4,4'-dihydroxy-3,3'-dimethoxylignan from the spectral data of FAB-MS. $^1H-\;and\;^{13}C-NMR$ spectrometries. The compound was also shown to have relatively strong antibacterial activity against ten types of cariogenic oral bacteria and one kind of Actinomyces sp.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.1
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• pp.124-134
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• 2006

Statement of problem: Streptococcus produces energy and forms extracellular polysaccharides by metabolizing sucrose. Insoluble glucan, a kind of extracellular polysaccharide, is the important material of dental plaque. Fructose affects the metabolism of sucrose. Purpose: The purpose of this study was to evaluate the effect of fructose on the metabolism of sucrose in Streptococcus mutans. Materials and methods: To determine the effect of fructose on the formation of artificial plaque by Streptococcus mutans Ingbritt, S. mutans and fructose were placed in beakers containing M17 broth and sucrose. The wires were hung on frameworks inserted into cork stoppers, and then immersed in each of the beakers. After the incubation with gentle shaking, each wire was weighed. To analyze the effect of fructose on the sucrose metabolism by S. mutans or glucosyltransferase, S. mutans and fructose were placed in M17 broth containing sucrose. After the incubation. the remaining sucrose and polymers were analysed by thin layer chromatography. Results: The following results were obtained; 1. When Streptococcus mutans was cultured in the media containing 3% sucrose for 8 hours, the mean weight of formed artificial plaque on the wires was $124.3{\pm}3.0mg$, whereas being reduced to $20.7{\pm}10.2mg$ in the media added with 3% sucrose and 4% fructose(p<0.05) 2. When the control containing glucose was added with sucrose, the optical density of Streptococcus mutans solution cultured for 24 hours was not increased compared with the control, while being increased by adding with fructose. 3. When Streptococcus mutans was incubated in the media added with sucrose and fructose for 8 hours, the number of viable cells was increased compared with the media added with sucrose. 4. The amount of remained sucrose was increased in Streptococcus mutans culture supernatant of media added with sucrose and fructose than with sucrose only. but the amount of produced insoluble glucan was decreased. 5. The amounts of remained sucrose and produced soluble glucan were increased in the culture of glucosyltransferase-contained media added with sucrose and fructose than with sucrose only, but the amount of produced insoluble glucan was decreased . Conclusion: These results indicated that the sucrose metabolism and the production of insoluble glucan were inhibited in Streptococcus mutans by adding fructose in the media containing sucrose.

• Korean Journal of Plant Tissue Culture
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• v.24 no.4
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• pp.233-238
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• 1997

Salicylic acid (SA) is involved in the establishment of systemic acquired resistance (SAR) in many plant including tobacco. Considering the important role of SA in disease resistance, biosynthetic and metabolic pathways of SA in tobacco have been studied extensively: The initial step for biosynthetic pathway of SA is conversion of phenylalanine to trans-cinnamic acid, followed by decarboxylation of trans-cinnamic acid to benzoic acid and ie subsequent ring hydroxylation at the C-2 position to form SA. In TMV inoculated tobacco, most of the newly synthesized SA is glucosylated or methylated. Methyl salicylate has been identified as a biologically active, volatile signal. In contrast, the two glucosylated forms accumulate in the vicinity of lesions and consist of SA glucoside, a major metabolite, and SA glucose ester, a relatively minor from. Two enzymes involved in SA biosynthesis and metabolism have been purified and characterized : benzoic acid 2-hydroxylase which catalyzes conversion of benzoic acid to SA; UDP-Glucose: SA 1-O-D glucosyltransferase which converts SA to SA glucose ester. Further studies of the biosynthetic and metabolic pathways of SA will help to elucidate the SAR signal transduction pathway and provide potential tools for the manipulation of disease resistance.

• Journal of Korean society of Dental Hygiene
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• v.14 no.1
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• pp.117-122
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• 2014

Objectives : The purpose of the study is to investigate the activities of Nelumbo nucifera leaf extracts on Streptococcus mutans, Streptococcus mitis, Streptococcus sobrinus, Porphyromonas gingivalis, Prevotella intermedia, and Treponema denticola. Methods : The inhibitory effect of lotus leaf extracts on the growth of oral bacteria was assessed in experiments with extracts from freshly harvested and pulverized lotus leaves and bacterial cultures of dental caries. Results : The results showed that N. nucifera extracts possess antimicrobial activity on all bacterial strains. The minimal inhibitory concentration (MIC) values varied from 4 mg/ml to 10 mg/ml against antimicrobial activity. The relative growth ratio (RGR) against of N. nucifera extracts were determined as 50% in concentration of 4.0 mg/ml. The extract of N. nucifera was effective in reducing on the glucosyltransferase (GTase) activity of six strains in vitro. Conclusions : Methanol extracts of lotus leaves showed antimicrobial effects on three bacterial species causing dental caries and three bacterial species causing periodontitis, as well as inhibitory effects on GTase activity.

• KSBB Journal
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• v.7 no.1
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• pp.79-83
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• 1992

The characteristics of Erwinia rhapontici cells with $\alpha$-glucosyltransferase activity immobilized in Ca-alginate beads and the performance of two different types of reactor-stirred tank reactor(STR) and packed bed reactor(PBR)-charged with these immobilized cells to produce palatinose from sucrose were investigated. The optimal pH(5.5-6.0) and temperature($30-35^{\circ}C$) showed no appreciable difference between free and immobilized cells. The apparent Km value of the immobilized cells(0.28M) was approximately two times higher than that of free cells(0.13M) at $30^{\circ}C$. The half life of the immobilized cells was found to be 380 h with STR while much greater operational stability was achieved with PBR. Continuous operation of PBR at a space velocity of $0.2h^{-1}$ for 30 days showed only 5% loss of initial activity.

• The Plant Pathology Journal
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• v.35 no.5
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• pp.530-537
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• 2019

Fuji, a major apple cultivar in Korea, is susceptible to white rot. Apple white rot disease appears on the stem and fruit; the development of which deteriorates fruit quality, resulting in decreases in farmers' income. Thus, it is necessary to characterize molecular markers related to apple white rot resistance. In this study, we screened for differentially expressed genes between uninfected apple fruits and those infected with Botryosphaeria dothidea, the fungal pathogen that causes white rot. Antimicrobial tests suggest that a gene expression involved in the synthesis of the substance inhibiting the growth of B. dothidea in apples was induced by pathogen infection. We identified seven transcripts induced by the infection. The seven transcripts were homologous to genes encoding a flavonoid glucosyltransferase, a metallothionein-like protein, a senescence-induced protein, a chitinase, a wound-induced protein, and proteins of unknown function. These genes have functions related to responses to environmental stresses, including pathogen infections. Our results can be useful for the development of molecular markers for early detection of the disease or for use in breeding white rotresistant cultivars.

• Korean Journal of Microbiology
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• v.54 no.4
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• pp.445-447
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• 2018

Leuconostoc lactis CCK940, which was isolated from kimchi obtained from a Korean traditional market, produced an oligosaccharide with a degree of polymerization of more than 4. In this study, the draft genome sequence of L. lactis CCK940 was reported by using PacBio 20 kb platform. The genome of this strain was sequenced and the genome assembly revealed 2 contigs. The genome was 1,741,511 base pairs in size with a G + C content of 43.33%, containing 1,698 coding sequences, 12 rRNA genes, and 68 tRNA genes. L. lactis CCK940 contained genes encoding glycosyltransferase, sucrose phosphorylase, maltose phosphorylase, and ${\beta}$-galactosidase which could synthesize oligosaccharide.

• Journal of Plant Biotechnology
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• v.49 no.4
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• pp.292-2999
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• 2022

Anthocyanin, an important component in the grape berry skin, strongly affects grape quality. The transcription factors VvMYBA1 and VvMYBA2 (VvMYBA1/2) control anthocyanin biosynthesis. In addition, cultivation and environmental factors, such as light, influence anthocyanin accumulation. The present study aimed to clarify the effect of shading (reduced light condition) on the transcriptomic regulation of anthocyanin biosynthesis using a red-wine grape cultivar, Vitis vinifera 'Pinot Noir', and its white mutant, 'Pinot Blanc', caused by the deletion of the red allele of VvMYBA1/2. The grape berry skins were analyzed for anthocyanin content and global gene transcription accumulation. The microarray data were later validated by quantitative real-time PCR. A decisive influence of VvMYBA1/2 on the expression of an anthocyanin-specific gene, UDP glucose: flavonoid 3-O-glucosyltransferase, was observed as expected. In contrast, upstream genes of the pathway, which are shared by other flavonoids, were also expressed in 'Pinot Blanc', and the mRNA levels of some of these genes decreased in both cultivars on shading. Thus, the involvement of light-sensitive transcription factor(s) other than VvMYBA1/2 was suggested for the expression control of the upstream genes of the anthocyanin biosynthetic pathway. Furthermore, it was suggested that the effects of these factors are different among isogenes.

• International Journal of Industrial Entomology and Biomaterials
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• v.1 no.2
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• pp.111-114
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• 2000

The female pupae of the silkworms Bombyx mori, were injected with recombinant Autographa californica nuclear polyhedrosis virus (AcNPV) expressing green fluorescent protein (GFP) by percutaneous inoculation. When the 4 day-old female pupae were injected with 1x10$^{7}$ or 2${\times}$10$^{7}$ plaque forming units (pfu) of the recombinant AcNPV, oviposited number and egg weight were significantly decreased. Furthermore, the shape of the eggs was obviously divides into normal and abnormal shapes. The percentage of the eggs with an abnormal shape was 7.8% and 57.1% at 1${\times}$10$^{7}$ and 2${\times}$10$^{7}$ pfu inoculation, respectively. PCR analysis of the genomic DNA extracted from the eggs revealed that gfp and AcNPV ecdysteroid UDP-glucosyltransferase genes were amplified from both types of eggs with normal and abnormal shapes. The results demonstrate that AcNPV DNA, and gfp gene cloned into the AcNPV genome, injected in pupal stage were transmitted to eggs and remained stable through at least next generation.

• Molecules and Cells
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• v.27 no.5
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• pp.577-582
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• 2009

The development of a high-throughput functional genomic screening provides a novel and expeditious approach in identifying critical genes involved in specific biological processes. Here we describe a cell-based cDNA screening system to identify the transcription activators of BiP, an endoplasmic reticulum (ER) chaperone protein. BiP promoter contains the ER stress element which is commonly present in the genes involved in unfolded protein response (UPR) that regulates protein secretion in cells. Therefore, the positive regulators of BiP may also be utilized to improve the recombinant protein production through modulation of UPR. Four BiP activators, including human UDP-glucose:glycoprotein glucosyltransferase 1 (HUGT1), are identified by the cDNA screening. Overexpression of HUGT1 leads to a significant increase in the production of recombinant erythropoietin, interferon ${\gamma}$, and monoclonal antibody in HEK293 cells. Our results demonstrate that the cDNA screening for BiP activators may be effective to identify the novel BiP regulators and HUGT1 may serve as an ideal target gene for improving the recombinant protein production in mammalian cells.