• Journal of Microbiology and Biotechnology
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• v.30 no.6
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• pp.937-945
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• 2020

N-acyl-homoserine lactone (AHL)-mediated quorum sensing (QS) plays a major role in development of biofilms, which contribute to rise in infections and biofouling in water-related industries. Interference in QS, called quorum quenching (QQ), has recieved a lot of attention in recent years. Rhodococcus spp. are known to have prominent quorum quenching activity and in previous reports it was suggested that this genus possesses multiple QQ enzymes, but only one gene, qsdA, which encodes an AHL-lactonase belonging to phosphotriesterase family, has been identified. Therefore, we conducted a whole genome sequencing and analysis of Rhodococcus sp. BH4 isolated from a wastewater treatment plant. The sequencing revealed another gene encoding a QQ enzyme (named jydB) that exhibited a high AHL degrading activity. This QQ enzyme had a 46% amino acid sequence similarity with the AHL-lactonase (AidH) of Ochrobactrum sp. T63. HPLC analysis and AHL restoration experiments by acidification revealed that the jydB gene encodes an AHL-lactonase which shares the known characteristics of the α/β hydrolase family. Purified recombinant JydB demonstrated a high hydrolytic activity against various AHLs. Kinetic analysis of JydB revealed a high catalytic efficiency (k_cat/K_M) against C4-HSL and 3-oxo-C6 HSL, ranging from 1.88 x 10⁶ to 1.45 x 10⁶ M^-1 s^-1, with distinctly low K_M values (0.16-0.24 mM). This study affirms that the AHL degrading activity and biofilm inhibition ability of Rhodococcus sp. BH4 may be due to the presence of multiple quorum quenching enzymes, including two types of AHL-lactonases, in addition to AHL-acylase and oxidoreductase, for which the genes have yet to be described.

• Journal of Pharmaceutical Investigation
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• v.27 no.4
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• pp.287-293
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• 1997

To make a stable o/w emulsion, the effects of egg lecithin as an emulsifier and polyvinylpyrrolidone (PVP) as an auxiliary emulsifier on the physical stability of emulsion were investigated. The oil-in-water emulsion system was manufactured by microfluidizer and evaluated the physical stability. Average particle size and size distribution of emulsion was measured by dynamic light scattering analyzer and interfacial tension was measured. From the interfacial tension tested, critical micelle concentration of the egg lecithin was 0.1 %w/v and optimal concentration for the preparation of emulsion was 1.0 %w/v. The mean particle size was about $0.2\;{\mu}m$ which was suitable for injections. The short-term accelerated stability studies were conducted by centrifugation, freeze-thaw method and shaking of the emulsion samples. The addition of PVP was caused the reduction in the particle size and improved the physical stability of emulsion. These results suggested that a mixed interfacial film comprising the egg lecithin and PVP was formed at the o/w interface and it was effective in preventing phase separation under thermic or mechanical stress. We used antineoplaston A10 (A10) as a model drug which is peptide and amino acid derivative having a action to the living organism against the development of neoplastic growth by a nonimmunological progress. It has a poor solubility in water and there may be a difficulty in formulation of A10. Emulsion formulation study about A10 was performed. Solubility of A10 in emulsion was about five times as high as that in water. From the results of solubility and partition coefficient, almost A10 molecules in o/w emulsion exist in the interface between oil and water.

• Applied Biological Chemistry
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• v.36 no.6
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• pp.517-524
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• 1993

To characterize glutelins, the most abundant storage protein in rice, 13 complete coding sequences of glutelin genes from the database were analyzed. According to the phylogenic analysis, these genes could be classified into 5 groups, Group I to V. The degrees of homology were calculated to be in the range of 90 to 60%, but the patterns of hydrophobicity were similar in all the groups. Also, each group was found to have similar amino acid composition with variations in lysine content from 2.5 to 3.6% due to the point mutation of arginine to lysine. The isoelectric points of mature proteins and their basic chains of all the groups showed the value of about 9.0 and 10.0, respectively, while the isoelectric points of acidic chains in these groups showed the distinct value of 6.6, 6.7, 7.2, 8.4 and 7.9. The plot of the fraction of G+C at synonimous site in codons (GC3s) against effective codon numbers suggest no major difference in translational efficiency in the expression of glutelin multigenes.

• Applied Biological Chemistry
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• v.46 no.4
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• pp.353-360
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• 2003

For the simple rapid bioassay of organophosphorus and carbamate pesticide residues, a mass-production system of acetycholinesterase (AChE, EC 3.1.1.7, MAChE) using baculovirus and insect cell culture was constructed. The cDNA for AChE was synthesized from Drosophila melanogaster in Halla Mountain, the lipid anchor tail was removed by PCR and was used for the site-directed mutagenesis of three amino acid residues (E107Y, F368L, L408F). The mutated cDNA was inserted into the baculovirus vector and expressed in insect cells. Maximum cell growth and enzyme activity were reached when the cells $(2{\times}10^6\;cell/ml)$ were infected four times at four-day-intervals. His-tag containing MAChE was purified using Ni-NTA column and used for characterization. The activity was maintained under various pHs (3-10) and temperatures $(20-50^{\circ}C)$ under experimental conditions. As an extraction solution for pesticides, methanol is more effective than ethanol. Against major organophosphate and carbamate pesticides, the MAChE showed better sensitivity than AChE and AChE from housefly (Taiwan).

• Applied Biological Chemistry
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• v.46 no.2
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• pp.79-83
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• 2003

Elicitins, proteinaceous elicitors secreted from Oomycetes fungi (Phytophthora spp. and Pythium spp.), have been known as inducer of hypersensitive response (HR) in incompatible interactions between plant and pathogens. Five elicitins among many Korean Phytophthora species caused the reactions of distal HR in radish, chinese cabbage and some hot pepper cultivars, but not in cucumber and tomato. Because the isolation of elicitin from Phytophthora cambivora hasn't been reported yet, we have purified a cambivorein, a new member of the elicitin family, from the culture filtrate of Phytophtilora cambivora (KACC 40160) by using FPLC (Fast Protein Liquid Chromatography, AKTA) with sepharose S and Sephacryl HR columns. We confirmed that it induces necrosis activities in some hot pepper cultivars and its molecular weight is about 10 KDa by Tricine-SDS-PAGE. Comparison of amino acid sequences of its N-terminal ends also informed the identification of Iysine at the 13th position, which is characteristic of a kind of basic elicitin isoform $({\beta}-isoform)$. It Also showed that our elicitin is not identical with N-terminal sequences of many elicitins reported from Phytophthora spp..

• Journal of Food Hygiene and Safety
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• v.30 no.1
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• pp.74-80
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• 2015

In this study, the microbial control effect after treatment of washing solutions (tap water, electrolyzed water, chlorine dioxide solution) and quality changes were investigated when Kwamegi is produced by means of the cold air drying. The initial moisture rate of the sample was 56.62% before drying. At the beginning of drying period, moisture rate sharply fell down but as the experiment progressed, moisture reducing rate was smoothly decreased. The color difference of Kwamegi before drying was 42.40, but it was reduced depending on the increment of drying temperature and time. TBA value of the initial sample was 0.219, rancidity were increased continuously when drying progressed. Total amino acid content was showed the highest value at $25^{\circ}C$ for 36h and the lowest at $40^{\circ}C$ for 12h. From the fatty acids analysis, major fatty acids were consisted of the 14:0, 16:0 and 18:1 (18.1520.96%, 28.0632.51% and 17.0619.81%, respectively). The microbial control effect was biggest when Kwamegi was washed with chlorine dioxide 100ppm for 60s. The microbe of the Kwamegi, Pseudomonas sp. and Pseudomonas putida were identified.

• Korean Journal of Food Science and Technology
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• v.36 no.1
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• pp.152-157
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• 2004

Gluten was extracted from domestic wheat flour using UTH buffer (4 M urea in 0.1 M Tris-HCl, pH 8.6) and validated by SDS-PAGE analysis for production of wheat flour products with reduced gluten content.. Anti-gluten polyclonal antibody was made by administering extracted gluten fraction on animal model. Anti-gluten serum titer of extracted gluten fraction was evaluated by ELISA, and that of antibody titer according to administration period. Anti-gluten sera were used for ELISA and immunoblot analysis before and after hydrolysis of gluten fraction at optimal pH and temperature condition for each protease. Gluten fraction separated by SDS-PAGE showed several bands covering 75 to 10 kDa, in which anti-gluten sera were 25, 34, and 45 kDa. Enzyme hydrolysis of gluten fraction revealed protein band sizes to be lower than 15 kDa. Content of pretense from bovine pancreas (b.p. protease) for gluten hydrolysis was estimated as 1 mg in 10 mL gluten fraction extracted for 4 hr.

• Korean Journal of Food Science and Technology
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• v.39 no.3
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• pp.276-282
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• 2007

In this study, attempts were made to develop a garlic juice extraction method that would result in minimum changes in quality. Protopectinase and a mutienzyme containing cellulase, pectinesterase, ${\beta}-glucanase$, etc. were applied to garlic residue after first extraction, and the yields of garlic juice and the flavor component changes of the juices were investigated. Enzyme concentrations of 0.04, 0.08, and 0.12% which were based on pulp weight before extraction were added and allowed to hydrolyze for 30, 60, 90 and 120 min,. respectively. Increase in the garlic juice yield was observed according to the amount of enzyme added and the reaction time until reaching a maximum point. When 0.12% protopectinase was applied to the garlic residue for 90 min, the yield increased by 13.8%. Under the same conditions, when multienzyme was applied to the garlic residue, the yield increased by 14.5%, which was considered the maximum. The flavor compounds decreased when compared with the total GC peak area of garlic juice prepared without enzymes(control). The volatile flavor compounds in garlic juice prepared with 0.12% protopectinase for 60 min decreased by 6%. The free sugars profile of the garlic juice prepared with 0.12% protopectinase for 60 min was similar to that of the control. The type of enzyme used did not affect the free amino acid profile of the garlic juice. These results indicate that the optimum conditions for extraction of garlic juice are hydrolyzing the residue with 0.12% protopectinase for 60 min, extracting garlic juice from the hydrolyzed reside, and then combining the extracted juice with the first extraction.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.6
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• pp.821-830
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• 2001

To study the effects of partial replacement of soybean meal (SBM) with palm kernel meal (PKM) and copra meal (CM) on growth performance, nutrient digestibility and carcass characteristics in finishing pigs, a total of 150 crossbred pigs (Landrace$\times$Duroc$\times$Yorkshire; average $52.11{\pm}1.08kg$ body weight) were alloted to five treatments, in a randomized block design. The treatments included 1) Control: without PKM or CM, 2) PKM2: 2% of palm kernel meal, 3) PKM4: 4% palm kernel meal, 4) CM2: 2% of copra meal, 5) CM4: 4% of copra meal. During the early finishing period (52~74 kg), growth performance was better in CM diets than in PKM diets or control diet, and in overall period (74~100 was lower (p<0.05) in PKM4 diet than the other diets. Nutrient digestibilies of PKM or CM substituted diets showed the tendency to be lower than those of control diet. In the early finishing period, total amino acid digestibilities of PKM and CM diets had the tendency to be lower than control diet, and in the late finishing period, they were lower (p<0.05) than control diet. Carcass length was longer (p<0.05) in the pigs fed 2% CM than in the pigs fed 4% PKM diet, but other carcass characteristics were not different among treatments. Although the dietary C14:0 content affected (p<0.05) on the C14:0 content in the carcass, the inclusion of PKM or CM in the diet did not affect the total saturated fatty acids and unsaturated fatty acids in the backfat of finishing pigs. Although it was not significant, supplementation of CM at the 2% and 4% of control group tended to decrease feed cost per kg weight gain by 2.89 to 1.42%, respectively. In conclusion, copra meal can be a valuable source of protein in the diet for finishing pigs and may replace other protein sources in pig diets to a considerable extent.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.11
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• pp.1614-1623
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• 2015

The objectives of the current experiment were to study the response of the growth performance of early finishing gilts to different net energy (NE) concentrations in diets, and to compare the NE values of diets between calculated NE values and measured NE values using French and Dutch CVB (Centraal Veevoederbureau; Central Bureau for Livestock Feeding) NE systems. In a metabolism trail, the NE concentrations in five diets used for the growth trial were determined based on digestible nutrient concentrations, digestible energy, and metabolizable energy using a replicated $5{\times}5$ Latin square design with 10 barrows (initial body weight [BW], $39.2{\pm}2.2kg$). In a growth trial, a total of 60 early finishing gilts (Landrace${\times}$Yorkshire; initial BW, $47.7{\pm}3.5kg$) were allotted to five dietary treatments of 8.0, 9.0, 10.0, 11.0, and 12.0 MJ NE/kg (calculated, as-is basis) with 12 replicate pens and one pig per pen in a 42-d feeding experiment. The NE and amino acid (AA) concentrations in all diets were calculated based on the values from NRC (2012). Ratios between standardized ileal digestible AA and NE concentrations in all diets were closely maintained. Pigs were allowed ad libitum access to feed and water. Results indicated that calculated NE concentrations in diets (i.e., five dietary treatments) were close to measured NE concentrations using French NE system in diets. The final BW was increased (linear and quadratic, p<0.05) with increasing NE concentrations in diets. Furthermore, average daily gain (ADG) was increased (linear and quadratic, p<0.01) with increasing NE concentrations in diets. There was a quadratic relationship (p<0.01) between average daily feed intake and NE concentrations in diets. Feed efficiency (G:F) was also increased (linear, p<0.01) as NE concentrations in diets were increased. The NE intake per BW gain (kcal NE/kg of BWG) was increased (linear, p<0.01) with increasing NE concentrations in diets that were predicted from both French and Dutch CVB NE systems. Linear regression indicated that predictability of daily NE intake from the BW of pigs was very low for both French ($R^2$, 0.366) and Dutch CVB ($R^2$, 0.374) NE systems. In conclusion, increasing NE concentrations in diets increase BW, ADG, G:F, and NE intake per BW gain of early finishing gilts. The BW of early finishing gilts is not a good sole variable for the prediction of daily NE intake.