Monitoring and evaluation of provincial classical swine fever immunization implementation with an E2 subunit vaccine in Jeju Island, South Korea.

Purpose: Accidental vaccination with a live attenuated low-virulence strain of Miyagi (LOM) vaccine led to the reemergence of classical swine fever virus (CSFV) in Jeju province, South Korea in 2014. To control the continual outbreaks of LOM-derived CSFV, the provincial government launched a provincial mass vaccination project using a CSF-E2 subunit vaccine. We conducted this study to assess the herd immunity level and outcomes of E2 vaccine-based immunization in breeding and growing herds on Jeju Island during 2020-2021.

Optimization of Microwave-Assisted Green Method for Enhanced Solubilization of Water-Soluble Curcuminoids Prepared Using Steviol Glycosides.

In this study, the optimization and modeling of microwave-assisted extraction (MAE) of water-soluble curcuminoids prepared using novel steviol glycosides (SGs) was carried out using four independent process variables at varying levels-: microwave power (50-200 W), : stevioside concentration (50-200 mg/mL), : curcumin concentration (20-200 mg/mL), and : time (1-10 min)-in response surface methodology configuration. Moreover, the effects of stevioside, as the most cost-effective natural solubilizer, were also evaluated. The water solubility of curcuminoids increased from 11 to 1320 mg/L with the addition of stevioside as a natural solubilizer.

Characterization of a lactic acid bacterium-derived β-glucosidase for the production of rubusoside from stevioside.

Rubusoside, which is used as a natural sweetener or a solubilizing agent for water-insoluble functional materials, is currently expensive to produce owing to the high cost of the membrane-based technologies needed for its extraction and purification from the sweet tea plant (Rubus suavissimus S. Lee). Therefore, this study was carried out to screen for lactic acid bacteria that possess enzymes capable of bio-transforming stevioside into rubusoside.

Enzymatic Synthesis of Glucosyl Rebaudioside A and its Characterization as a Sweetener.

Rebaudioside A was modified via glucosylation by recombinant dextransucrase of Leuconostoc lactis EG001 in Escherichia coli BL21 (DE3), forming single O-α-D-glucosyl-(1″→6') rebaudioside A with yield of 86%. O-α-D-glucosyl-(1″→6') rebaudioside A was purified using HPLC and Diaion HP-20 and its properties were characterized for possible use as a food ingredient. Almost 98% of O-α-D-glucosyl-(1″→6') rebaudioside A was dissolved after 15 days of storage at room temperature, compared to only 11% for rebaudioside A.

Biochemical Characterization of Alkaliphilic Cyclodextran Glucanotransferase from an Alkaliphilic Bacterium, .

Cycloisomaltooligosaccharide glucanotransferase (CITase) was isolated from alkaliphilic via an amino acid homology search for the reported CITase. The recombinant alkaliphilic CITase (PDCITase) from was expressed in an expression system and purified as a single protein band of 111 kDa. PDCITase showed optimum activity at pH 8.

Transglycosylation of gallic acid by using Leuconostoc glucansucrase and its characterization as a functional cosmetic agent.

Gallic acid glycoside was enzymatically synthesized by using dextransucrase and sucrose from gallic acid. After purification by butanol partitioning and preparative HPLC, gallic acid glucoside was detected at m/z 355 (C, H, O, Na) by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. The yield of gallic acid glucoside was found to be 35.

Enzymatic synthesis of chlorogenic acid glucoside using dextransucrase and its physical and functional properties.

Chlorogenic acid, a major polyphenol in edible plants, possesses strong antioxidant activity, anti-lipid peroxidation and anticancer effects. It used for industrial applications; however, this is limited by its instability to heat or light. In this study, we for the first time synthesized chlorogenic acid glucoside (CHG) via transglycosylation using dextransucrase from Leuconostoc mesenteroides and sucrose.

Synthesis and Functional Characterization of Caffeic Acid Glucoside Using Leuconostoc mesenteroides Dextransucrase.

Caffeic acid was modified via transglucosylation using sucrose and dextransucrase from Leuconostoc mesenteroides B-512FMCM. Following enzymatic modification, a caffeic acid glucoside was isolated by butanol separation, silica gel chromatography, and preparative HPLC. The synthesized caffeic acid glucoside had a molecular mass-to-charge ratio of 365 m/z, and its structure was identified as caffeic acid-3-O-α-d-glucopyranoside.

Synthesis and characterization of glucosyl stevioside using Leuconostoc dextransucrase.

Glucosyl stevioside was synthesized via transglucosylation by dextransucrase from Leuconostoc citreum KM20 (LcDexT), forming α-d-glucosyl stevioside. A production yield of 94% was reached after 5days of LcDexT reaction at 30°C. Glucosyl stevioside induced a 2-fold improved quality of taste and sweetness, compared to stevioside.

Identification of Catalytic Amino Acid Residues by Chemical Modification in Dextranase.

A novel endodextranase isolated from Paenibacillus sp. was found to produce isomaltotetraose and small amounts of cycloisomaltooligosaccharides with a degree of polymerization of 7-14 from dextran. To determine the active site, the enzyme was modified with 1-ethyl-3-[3- (dimethylamino)-propyl]-carbodiimide (EDC) and α-epoxyalkyl α-glucosides (EAGs), an affinity labeling reagent.

Glucosyl Rubusosides by Dextransucrases Improve the Quality of Taste and Sweetness.

Glucosyl rubusosides were synthesized by two dextransucrases. LcDexT was obtained from Leuconosotoc citreum, that LlDexT was obtained from Leuconostoc lactis. LcDexT and LlDexT regioselectively transferred a glucosyl residue to the 13-O-glucosyl moiety of rubusoside with high yield of 59-66% as analyzed by TLC and HPLC.

Crystal structure of thermophilic dextranase from Thermoanaerobacter pseudethanolicus.

The crystal structures of the wild type and catalytic mutant Asp-312→Gly in complex with isomaltohexaose of endo-1,6-dextranase from the thermophilic bacterium Thermoanaerobacter pseudethanolicus (TpDex), belonging to the glycoside hydrolase family 66, were determined. TpDex consists of three structural domains, a catalytic domain comprising an (β/α)8-barrel and two β-domains located at both N- and C-terminal ends. The isomaltohexaose-complex structure demonstrated that the isomaltohexaose molecule was bound across the catalytic site, showing that TpDex had six subsites (-4 to +2) in the catalytic cleft.

Chalcones isolated from Angelica keiskei inhibit cysteine proteases of SARS-CoV.

Two viral proteases of severe acute respiratory syndrome coronavirus (SARS-CoV), a chymotrypsin-like protease (3CL(pro)) and a papain-like protease (PL(pro)) are attractive targets for the development of anti-SARS drugs. In this study, nine alkylated chalcones (1-9) and four coumarins (10-13) were isolated from Angelica keiskei, and the inhibitory activities of these constituents against SARS-CoV proteases (3CL(pro) and PL(pro)) were determined (cell-free/based). Of the isolated alkylated chalcones, chalcone 6, containing the perhydroxyl group, exhibited the most potent 3CL(pro) and PL(pro) inhibitory activity with IC50 values of 11.

Purification and functional characterization of the first stilbene glucoside-specific β-glucosidase isolated from Lactobacillus kimchi.

This study aimed to develop viable enzymes for bioconversion of resveratrol-glucoside into resveratrol. Out of 13 bacterial strains tested, Lactobacillus kimchi JB301 could completely convert polydatin into resveratrol. The purified enzyme had an optimum temperature of 30-40°C and optimum pH of pH 5.

Characterization of a novel steviol-producing β-glucosidase from Penicillium decumbens and optimal production of the steviol.

This study aimed to develop an economically viable enzyme for the optimal production of steviol (S) from stevioside (ST). Of 9 commercially available glycosidases tested, S-producing β-glucosidase (SPGase) was selected and purified 74-fold from Penicillium decumbens naringinase by a three-step column chromatography procedure. The 121-kDa protein was stable at pH 2.

Enzymatic synthesis of puerarin glucosides using Leuconostoc dextransucrase.

Puerarin (P), an isoflavone derived from kudzu roots, has strong biological activities, but its bioavailability is often limited by its low water solubility. To increase its solubility, P was glucosylated by three dextransucrases from Leuconostoc or Streptococcus species. Leuconostoc lactis EG001 dextransucrase exhibited the highest productivity of puerarin glucosides (P-Gs) among the three tested enzymes, and it primarily produced two P-Gs with a 53% yield.

Biochemical characterization of thermophilic dextranase from a thermophilic bacterium, Thermoanaerobacter pseudethanolicus.

TPDex, a putative dextranase from Thermoanaerobacter pseudethanolicus, was purified as a single 70 kDa band of 7.37 U/mg. Its optimum pH was 5.

Large increase in Leuconostoc citreum KM20 dextransucrase activity achieved by changing the strain/inducer combination in an E. coli expression system.

A recombinant putative dextransucrase (DexT) was produced from Leuconostoc citreum KM20 as a 160 kDa protein, but its productivity was very low (264 U/l). For optimization, we examined enzyme activity in 7 Escherichia coli strains with inducer molecules such as lactose or IPTG. E.

Mass production of rubusoside using a novel stevioside-specific β-glucosidase from Aspergillus aculeatus.

Rubusoside (R) is a natural sweetener and a solubilizing agent with antiangiogenic and antiallergic properties. However, currently, its production is quite expensive, and therefore, we have investigated nine commercially available glycosidases to optimize an economically viable R-production method. A stevioside (ST)-specific β-glucosidase (SSGase) was selected and purified 7-fold from Aspergillus aculeatus Viscozyme L by a two-step column chromatography procedure.