• Journal of the Korean Geosynthetics Society
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• v.22 no.2
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• pp.13-21
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• 2023

Mean sea level has recently been rising due to global warming causing coastal erosion. As Korea is peninsula, the land loss due to coastal erosion is critical. An approach in this study is cementing the coastal area using bacteria, which is called microbially induced carbonate precipitation (MICP). This study tried to see how fresh water and sea water work with MICP as a solvent. Ureolytic activity during the MICP reaction was measured with deionized and sea water. A soil column was prepared to evaluate the strength of MICP-treated sand. Sands were treated by MICP with surface percolation method. As the treatmen t style was different with other conventional methods, several methods were proposed to properly evaluate the MICP-treated sand surface. A micro-scale evaluation was performed to assess the mineral structure treated by different solvents. As results, sea water rendered the ureolytic reaction slower. A needle penetrometer worked well to evaluate the MICP-treated sand surface. This study confirmed the utilization of sea water is feasible as the solvent of MICP.

• Animal Bioscience
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• v.37 no.6
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• pp.1077-1084
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• 2024

Objective: The present work was conducted to evaluate suitable variables and develop prediction equations using chemical composition and physical characteristics for estimating standardized ileal digestibility (SID) of lysine (Lys) in full-fat soybeans (FFSB). Methods: The chemical composition and physical characteristics were determined including trypsin inhibitor activity (TIA), urease activity (UA), protein solubility in 0.2% potassium hydroxide (KOH), protein dispersibility index (PDI), lysine to crude protein ratio (Lys:CP), reactive Lys:CP ratio, neutral detergent fiber, neutral detergent insoluble nitrogen (NDIN), acid detergent insoluble nitrogen (ADIN), acid detergent fiber, L* (lightness), and a* (redness). Pearson's correlation (r) was computed, and the relationship between variables was determined by linear or quadratic regression. Stepwise multiple regression was performed to develop prediction equations for SID of Lys. Results: Negative correlations (p<0.01) between SID of Lys and protein quality indicators were observed for TIA (r = -0.80), PDI (r = -0.80), and UA (r = -0.76). The SID of Lys also showed a quadratic response (p<0.01) to UA, NDIN, TIA, L*, KOH, a* and Lys:CP. The best-fit model for predicting SID of Lys in FFSB included TIA, UA, NDIN, and ADIN, resulting in the highest coefficient of determination (R² = 0.94). Conclusion: Quadratic regression with one variable indicated the high accuracy for UA, NDIN, TIA, and PDI. The multiple linear regression including TIA, UA, NDIN, and ADIN is an alternative model used to predict SID of Lys in FFSB to improve the accuracy. Therefore, multiple indicators are warranted to assess either insufficient or excessive heat treatment accurately, which can be employed by the feed industry as measures for quality control purposes to predict SID of Lys in FFSB.

• Journal of Animal Science and Technology
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• v.51 no.3
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• pp.217-224
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• 2009

This study was carried out to investigate the nutritional value of soybean meal (SBM) from various geographic origins and the effects of their dietary supplementation on performance of broiler chickens. Nutritional value of dehulled SBM originating from USA, and non-dehulled SBM from India (IND), Argentina (ARG) and Korea (KOR) were evaluated by analyzing chemical composition, urease activity (UA) and KOH solubility, and determining true metabolizable energy (TME), nitrogen corrected TME (TMEn) and true amino acid availability (TAAA). The contents of crude protein ranged from 45.43% (ARG) to 48.47% (USA) and those of crude fiber varied widely from 3.48% (USA) to 7.12% (IND). The measurements of lysine varied from 2.79% (IND) to 3.09% (USA) and those of methionine from 0.56% (IND) to 0.65% (USA). The values of TMEn varied from 2986.6 kcal/kg (IND) to 3228.9 kcal/kg (USA) and the averages of TAAA were from 91.61% (IND) to 92.27% (USA). UA was found to be from 0.02 (ARG) to 0.04 (KOR, USA) and those of KOH solubility from 73% (ARG) to 84% (USA). A total of four hundred 20-days-old male broiler chicks were divided into four groups and fed with isocaloric and isonitrogenous experimental diets containing 27.5% of SBM and same amounts of lysine and sulfur amino acids for 15 days. Final body weight and body weight gain were the highest in birds fed with SBM from USA and lowest in birds fed with SBM from IND although the differences were not statistically significant. The feed/gain in chicks fed diet containing SBM from USA was significantly improved (p<0.05) compared to those of the other groups. There were no significant differences in carcass characteristics and the concentration of total cholesterol in serum among the treatments. The results of in vitro assay and bioassay agreed with the performance of broiler chicks, and thus there were close correlation between the broiler performance and the measured nutritive values of SBM. In conclusion, dehulled SBM from USA was superior to non- dehulled SBM from ARG and IND with regard to nutritive values.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.6
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• pp.394-400
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• 2001

This experiment was conducted to determine the safety and feasibility of using compost-promoting-bacteria. Compost-promoting-bacteria was isolated from livestock compost containing sawdust. The isolated bacteria was identified as Bacillus subtilis LYH201 by the method of the composition of the fatty acid with MIDI system and Bergey's manual. This Bacillus subtilis LYH201 had the following characteristics : Gram-positive, straight rod ($0.5{\sim}0.7{\mu}m$ width, $2.5{\sim}3.0{\mu}m$ length), facultatively aerobic and product of xylanase, CMCase, catalase, oxidase, protease and $0.5{\sim}0.7{\mu}m$-amylase. Growth of Bacillus subtilis LYH201 at saccharose as carbon source(0.5%) was faster than other carbon source. Activity of cellulase. $0.5{\sim}0.7{\mu}m$-amylase and protease from Bacillus subtilis LYH201 after 24 hours at $50^{\circ}C$ by agar diffusion method was higher than that of low temperature. Optimum growth condition of Bacillus subtilis LYH201 was $50^{\circ}C$ and pH 6.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.2
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• pp.129-133
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• 1995

A feeding trial was conducted to evaluate the effects of crude protein concentration (44% vs 48%) and extrusion processing of soybean meal (SBM) on the performance of weanling and growing pigs. One hundred and ninety two (96 pigs of each sex) 3 way crossed (Landrace ${\times}$ Hampshire ${\times}$ Duroc) weaned pigs were allotted to 12 pens each of 16 pigs (8 pigs of each sex). Three pens were assigned to each of the 4 treatment; $T_1$; 44% SBM diet, $T_2$; extruded 44% SBM diet, $T_3$; 48% SBM diet and $T_4$; extruded 48% SBM diet. The 44% SBM diet was formulated to have 18% CP for the starter phase (5-10 wk of age) and 15% CP for the grower phase (10-15 wk of age). The other treatments used equivalent amount of each SBM, replacing the 44% SBM. Chemical assay showed that extrusion processing generally decreased amino acid content especially total lysine and available lysine. Extrusion increased Hunterlab color +a value and decreased the urease activity index. The body weight gains for the $T_3$ and $T_4$ pigs were significantly(p < 0.05) greater than for those on $T_1$ and $T_2$ for the starter phase, but not the grower phase. Extrusion processing did not improve weight gain. Feed intake for the overall period was significantly(p < 0.05) different among treatments. The feed conversion ratios were not significantly different among treatments. An economic analysis showed that the high protein (48%) SBM diet was more cost effective than the low protein(44%) SBM diet, for the starter phase.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.22
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• pp.9905-9908
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• 2014

Background: Helicobacter pylori (H. pylori) is the most common chronic infectious agent in the stomach. Most importantly, it may lead to atrophy, metaplasia and cancer. The aim of this study was to investigate the incidence of H. pylori infection and to detect early mucosal changes that may lead to malignant degeneration in children. Materials and Methods: Children who underwent upper gastrointestinal endoscopy were included. Familial history of gastric cancer was noted. Endoscopic examinations were performed by a single pediatric gastroenterologist. A minimum of three biopsy samples were collected during endoscopy. The patients were accepted as H. pylori infected if results of biopsies and rapid urease test were both positive. Biopsies were evaluated for the presence and degree of chronic inflammation, the activity and severity of gastritis, glandular atrophy and intestinal metaplasia. Results: A total of 750 children (388 boys, 362 girls) were evaluated in our study, with a mean age of 10.1 years. A total of 390 patients (52%) were found to be infected with H. pylori. Among the H. pylori infected patients, 289 (74%) were diagnosed to have chronic superficial gastritis, 24 (6.2%) had gastric atrophy. Most strikingly, intestinal metaplasia was observed in 11 children, all were in the H. pylori positive group. There was no difference in the mean of age, gender and socioeconomic class between H. pylori infected and non-infected groups. The frequency of gastric cancer in family members (4 in number) was higher in patients with H. pylori infection. No gastric cancer case was reported from the parents of non-infected children. The worst biopsy parameters (atropy and metaplasia) were improved after H. pylori eradication on control endoscopy. Conclusions: The current study shows a higher prevalence of familial history of gastric cancer in H. pylori infected children. Intestinal metaplasia was also higher in the infected children. Eradication of H. pylori infection for this risk group may prevent subsequent development of gastric cancer.

• Journal of Microbiology and Biotechnology
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• v.26 no.3
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• pp.540-548
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• 2016

Microbially induced calcium carbonate precipitation (CCP) is a long-standing but re-emerging environmental engineering process for production of self-healing concrete, bioremediation, and long-term storage of CO₂. CCP-capable bacteria, two Bacillus strains (JH3 and JH7) and one Sporosarcina strain (HYO08), were isolated from two samples of concrete and characterized phylogenetically. Calcium carbonate crystals precipitated by the three strains were morphologically distinct according to field emission scanning electron microscopy. Energy dispersive X-ray spectrometry mapping confirmed biomineralization via extracellular calcium carbonate production. The three strains differed in their physiological characteristics: growth at alkali pH and high NaCl concentrations, and urease activity. Sporosarcina sp. HYO08 and Bacillus sp. JH7 were more alkali- and halotolerant, respectively. Analysis of the community from the same concrete samples using barcoded pyrosequencing revealed that the relative abundance of Bacillus and Sporosarcina species was low, which indicated low culturability of other dominant bacteria. This study suggests that calcium carbonate crystals with different properties can be produced by various CCP-capable strains, and other novel isolates await discovery.

• Journal of Plant Biology
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• v.4 no.2
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• pp.51-61
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• 1961

In order to detect the way of absorption and metaboism of the urea it is sprayed on the surface of the leaves of sunflower. The sunflowers used in this study are grown in different conditions such that the one in nittogen aboundant and the other in nitrogen deficient soil, respectively. The urea-N, ammonia-N, amide-N, and 80% alcohol soluble-N in the leaves were quantitatively determined. All of the nitrogenous components measured are generally tended to increased with rising the concentration of urea except only amide-N at 24 hours after sprayed, and these were highly significances. It seemed that hydrolizing of urea into ammonia and carbon dixide and the assimilation of ammonia into other organic nitrogenous constituents were rapid in the young leaves than in the mature. It is interest that the amide content, in the young leaves and nitrogen defieient one were enhanced with the increasing concentration of urea, although in the mature leaves it did not show any change in the urea treatment. It is presumed that the assimilation rate of ammonia and the urease activity were lower in the matture leaves than in the young and nitrogen deficient leaves. No significance at 5% level showed all of the nitrogenous components except total nitrogen between nitrogen abundant and deficent leaves. Urea content was a high peak at first 12 hours, ammonia at 48 hours, and amide and alcohol soluble nitrogen at 96 hours, whence decrease4d the content of these constituents gradually. The total nitrogen content is not incrased obviously by only one time of urea spray in this study. When the concentration of urea was relatively high there appeared the wilting spots on t도 edge of leaves. As a whole, it seemed that sprayed urea was rapidly absorbed and taken part in nitrogen metabolism within relatively short period.

• Korean Journal of Microbiology
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• v.25 no.4
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• pp.346-352
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• 1987

One hundred and seventeen colonies were screened for the detection of the production of exodextranase on the dextran-mineral salts medium. Ten colonies out of them produced the dextranase. Flavobacterium multivorum greatly producing the enzyme was isolated from soil, identified and then studied for various biochemical characteristics. The activity of the dextranase in the cultured medium was high between pH8 and 9 at $35^{\circ}C$, and between $45^{\circ}C$ and $55^{\circ}C$ at pH8. By the growth curves the generation times of the bacterium were approximately 52 minutes in the LB broth, 38 minutes in the LB plus 1% dextran and 660 minutes in the dextran-salts. The strain did not have ant plasmid, and was susceptible to genramicin, cotrimoxazole and cefoperazone, and moderately susceptible to chloramphenicol, cefamandole and cefotaxime, but resistant to ampicillin, cephalothin, tetracycline, amikacin and tobramycin.

• Journal of Microbiology and Biotechnology
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• v.31 no.9
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• pp.1311-1322
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• 2021

Microbially induced calcium carbonate precipitation (MICP) has recently become an intelligent and environmentally friendly method for repairing cracks in concrete. To improve on this ability of microbial materials concrete repair, we applied random mutagenesis and optimization of mineralization conditions to improve the quantity and crystal form of microbially precipitated calcium carbonate. Sporosarcina pasteurii ATCC 11859 was used as the starting strain to obtain the mutant with high urease activity by atmospheric and room temperature plasma (ARTP) mutagenesis. Next, we investigated the optimal biomineralization conditions and precipitation crystal form using Plackett-Burman experimental design and response surface methodology (RSM). Biomineralization with 0.73 mol/l calcium chloride, 45 g/l urea, reaction temperature of 45℃, and reaction time of 22 h, significantly increased the amount of precipitated calcium carbonate, which was deposited in the form of calcite crystals. Finally, the repair of concrete using the optimized biomineralization process was evaluated. A comparison of water absorption and adhesion of concrete specimens before and after repairs showed that concrete cracks and surface defects could be efficiently repaired. This study provides a new method to engineer biocementing material for concrete repair.