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Molecular Elucidation of Two Novel Seed Specific Flavonoid Glycosyltransferases in Soybean
Gyuhwa Chung;Seung Hwan Yang,Hafiz Mamoon Rehman,Muhammad Amjad Nawaz,Zahid Hussain Shah 한국식물학회 2018 Journal of Plant Biology Vol.61 No.5
Flavonoids are specialized plant secondarymetabolites that are mainly present as glycoconjugates andfunction as attractants to pollinators and symbionts, UVprotectants, allelochemicals, and have antimicrobial andantiherbivore activity for plant health. Because of theheterogeneity of UDP-glycosyltransferases (UGTs) forglycosylation in plants, their function in flavonoid glycosylationremains largely unknown in soybean and other legumes,particularly that of the UGT92 genes. Here, we identified 152putative UGT92 genes across 48 plant species and elucidatedtheir mode of duplication, expansion/deletion pattern,alignment, phylogenetic analysis, and genome-wide distribution. Two novel UGT-encoding genes Glyma14g04790 (UGT92G1)and Glyma15g03670 (UGT92G2) were isolated fromsoybean and their heterologous expression was optimized inEscherichia. coli. Both genes exhibited catalytic activitytoward quercetin, kaempferol, and myricetin, with UDPglucoseas the sugar donor and were characterized asflavanol-specific UGTs. High expression of both UGTswas observed in adaxial and abaxial parenchyma, suspensorcells, and adaxial and abaxial epidermis cells during seeddevelopment, suggesting that they are seed-specific flavanolglycosyltransferases in soybean. Co-expression analysis ofUGT92 genes with their first and second neighborhood genesprovided a basis for their network elucidation in soybean. Weprovide valuable information on the role of UGT92 in seeddevelopment via the glycosylation of multiple flavanols andthe potential metabolic engineering of flavonoid compoundsin both plants and E. coli.
( Bao Le ),( Gyuhwa Chung ),( Seung Hwan Yang ) 한국응용생명화학회(구 한국농화학회) 2018 Journal of Applied Biological Chemistry (J. Appl. Vol.61 No.3
Chitinases are glycosyl hydrolases which cleave the β- 1,4 linkage of chitin into oligo or monomers of N-acetylglucosamine. These bacterial enzymes have been used for a wide range of applications in the food and pharmaceutical industries. In this study, we isolated two potential chitinolytic strains, BAO-01 and BAO-02, from salt-fermented shrimp, which were shown to belong to the genus Salinivibrio through genetic characterization using 16S rRNA. These isolates were gram-positive, rod-shaped, and non-spore forming. BAO-01 showed greater growth and chitinase activity than BAO-02 after the incubation at 37 oC for 4 days. Both strains grew on a wide range of carbon and nitrogen sources, pH values, temperatures, and salt levels. However, they showed minor biochemical differences. In addition, their antimicrobial activities against foodborne pathogens and antibiotic susceptibilities were evaluated. These Salinivibrio spp. did not show bioamine production, hemolytic activity, and mucin degradation. Therefore, the in vitro screening results suggested that these bacteria could be widely used as new candidates for chitin hydrolyzation and seafood fermentation.
( Fahima Akther ),( Bao Le ),( Gyuhwa Chung ),( Seung Hwan Yang ) 한국응용생명화학회(구 한국농화학회) 2017 Journal of Applied Biological Chemistry (J. Appl. Vol.60 No.4
Lactic acid bacteria (LAB) are widely used as starter culture in food fermentation due to their harmless entity and health beneficial properties along with the ability to change texture, aroma, flavor and acidity of food products. In this study, five different LAB (FB003, FB058, FB077, FB081, and FB111) isolated from different Korean traditional fermented foods, assigned to Lactobacillus plantarum, Pediococcus pentosaceus, Weissella viridescens, Lactobacillus sakei, and Leuconostoc mesenteroides, respectively, on the basis of their physiological properties and 16S rRNA sequence analysis, to use as fermentation starter and check their ability to fasten the ripening time as well as the overall optimization in the fermentation condition. To check their suitability as starters, their safety, acid and bile tolerance, NaCl and temperature resistance, susceptibility to common antibiotics, and antimicrobial activities were determined. Squid jeotgal samples were prepared by adding 10<sup>8</sup> CFU/g of each strain in different samples, which were then kept for fermentation at 4 ℃ and checked for their antioxidant activities at 0, 7, 15, and 21-day intervals. The samples fermented with FB003 and FB077 displayed the highest antioxidant activity. This study revealed two effective starter cultures (FB003, FB077) for squid jeotgal fermentation, which presented increased functionalities. The results of this study will lead to the development of novel industrial-scale production avenues for jeotgal preparation, and offer new insights into the prevention and control of chronic diseases.
( Fahima Akther ),( Jinhua Cheng ),( Seung Hwan Yang ),( Gyuhwa Chung ) 한국응용생명화학회 2017 Journal of Applied Biological Chemistry (J. Appl. Vol.60 No.2
Fermentation plays a vital role in the nutritional enrichment of food. Korea has a long tradition of adding fermented food to the daily diet and jeotgal is one of the common fermented and salted foods in Korean cuisine. In our study, we added soymilk as an additive to squid jeotgal to improve its functionality. We mixed different concentrations of soymilk (2, 5, and 10 mg/g) with squid jeotgal samples, fermented them for one week, and then tested their antioxidant and anticancer activities to compare with those of squid jeotgal samples without soymilk additive. To investigate the anticancer characteristics, glutathione-S-transferase (GST)-pi enzyme assay was used. To test the antioxidant activities, various assays were performed, including 2,2-diphenyl-1-picryl hydrazyl free radical scavenging activity, 2,2-azino-bis(3-ethyl-benzothiazoline- 6-sulfonic acid) diammonium saltradical cation scavenging assay, and reducing power assay. Samples fermented with a small amount of soymilk showed excellent anticancer activity. The addition of only 2 mg/g of soymilk to squid jeotgal inhibited the activity of GST-pi by almost 50% when compared with the sample with no addition. Moreover, no undesirable bitterness or astringency was noticed. Our results could help to improve the current food status of squid jeotgal and it could be used to reduce the risk of chronic disease along with its basic nutritional function.