• Korean Journal of Food Science and Technology
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• v.29 no.4
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• pp.804-807
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• 1997

Palatinose is a disaccharide molecule which can substitute sucrose as a sweetening agent. A microbial fermentation technology has been developed to produce palatinose. In order to verify the safety of palatinose products, we have performed 1) bacterial reverse mutation test using Salmonella typhimurium TA1535, TA1537, TA98 and TA100, and 2) in vitro chromosome aberration test using Chinese Hamster Lung (CHL) cell. In bacterial reverse mutation test, both palatinose and palatinose syrup did not induce any significant increase of $His^{+}$ revertants up to 10 mg/plate. In in vitro chromosome aberration test, palatinose and palatinose syrup also did not cause any significant increase of chromosome aberrant cells up to 5 mg/mL. These results suggest that palatinose products have no mutagenic potential in these in vitro mutagenicity tests.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.1
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• pp.118-123
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• 2021

This study was conducted to evaluate plant proteins as a replacement for a fishmeal diet in the rearing of coho salmon Oncorhynchus kisutch. Twelve groups of 20 fish averaging 34.0±0.62 g were randomly distributed into 12 rectangular tanks (250 L). Four experimental diets included a control diet containing 60% fishmeal (Control), and three other diets that replaced 20% of fishmeal with soy protein concentrate (SPC), fermented soybean protein concentrate (F-SPC), and enzyme-processed soy protein concentrate (E-SPC). At the end of the feeding trial, fish that were fed Control, SPC and E-SPC diets showed significantly higher weight gain, specific growth rate, feed efficiency, and protein efficiency ratio than those that were fed F-SPC diet. However, there were no significant differences among the fish that were fed Control, SPC, and E-SPC diets. No significant differences were observed in crude protein, crude lipid, and ash of whole body among the fish that were fed all the diets. Therefore, these results indicated that 20% of fishmeal could be replaced by E-SPC or SPC without any adverse effects on the growth performance of coho salmon.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.2
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• pp.134-140
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• 2019

A feeding trial was conducted to investigate the effects of dietary fish meal replacement by a blend of lysine cell mass, corn protein concentrate and poultry by-product meal on the growth and blood chemistry of the starry flounder Platichthys stellatus. The fish meal replacer (FMR) was prepared to have the same level of protein as fish meal (FM). With a commercial diet as a positive control, five experimental diets (basal, FM42, FM32, FM22 and FM12) were formulated to contain 52% protein and 10% lipid. The dietary FM levels decreased from 52% (basal) to 42, 32, 22 and 12% with concomitant increase in the FMR to 10, 20, 30, 40 and 50%, respectively. Juvenile starry flounder with an average body weight of 177.3 g were randomly distributed in each (30 fish/tank) of 18 plastic tanks ($139{\times}99{\times}54cm$). After a 45-day feeding trial, the survival rate ranged from 95.6% (FM22) to 100% (control and FM42), while the weight gain of the fish groups varied from 49.7 to 58.4 g. The results clearly revealed that starry flounder can grow well on a diet containing low FM (12%) with a high level of FMR (50%) without any adverse effects.

• Korean Journal of Environmental Agriculture
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• v.40 no.3
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• pp.219-230
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• 2021

BACKGROUND: Biochar is a solid material converted from agricultural biomass such as crop residues and pruning branch through pyrolysis under limited oxygen supply. Biochar consists of non-degradable carbon (C) double bonds and aromatic ring that are not readily broken down by microbial degradation in the soils. Due to the recalcitrancy of C in biochar, biochar application to the soils is of help in enhancing soil carbon sequestration in arable lands that might be a strategy of agricultural sector to mitigate climate change. METHODS AND RESULTS: Data were collected from studies on the effect of biochar application on soil C content conducted in East Asian countries including China, Japan and Korea under different experimental conditions (incubation, column, pot, and field). The magnitude of soil C storage was positively correlated (p < 0.001) with biochar application rate under field conditions, reflecting accumulation of recalcitrant black C in the biochar. However, The changes in soil C contents per C input from biochar (% per t/ha) were 6.80 in field condition, and 12.58 in laboratory condition. The magnitude of increment of soil C was lower in field than in laboratory conditions due to potential loss of C through weathering of biochar under field conditions. Biochar production condition also affected soil C increment; more C increment was found with biochar produced at a high temperature (over 450℃). CONCLUSION: This review suggests that biochar application is a potential measures of C sequestration in agricultural soils. However, as the increment of soil C biochar was affected by biochar types, further studies are necessary to find better biochar types for enhanced soil C storage.

• Microbiology and Biotechnology Letters
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• v.7 no.3
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• pp.119-125
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• 1979

As the first step of domestic developmint of the nucleic acid-related compounds, purine base required auxotrophs from Brevibacterium ammoniagenes ATCC 6872 were derived by the ultraviolet irradiation or the treatment of N-methyl-N'-nitro-N-nitroso guanidine (NTG), diethyl sulfate (DES), and ethylme-thyl sulfate (EMS). The optimum conditions of mutation by means of several mutagens were induced respectively. The yield of mutants was 0.083％ by the ultraviolet irradiation, 0.67％ by the NTG treatment, 1.1％ by the DES treatment, and 0.45％ by the EMS treatment. Six strains among 239 auxotrophs were screened out to accumulate 5'-lMP in the culture broth. Cry-stalline 5'-lMP was isolated from the culture broth of Brevifbacterium ammoniagenes adnine-guanine less mutant D-21530 by the use of anion exchange resin, Amberlite IRA-402, and it was identified physically and chemically as 5'-inosinic acid.

• Korean Journal of Food Science and Technology
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• v.51 no.3
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• pp.221-226
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• 2019

This study investigated the optimal amount of shell powder (0.1, 0.2, 0.3, and 0.4%) to add to rice noodles containing 20% rice flour and compared their quality characteristics to those of wheat noodles containing a commercial alkaline reagent (added at 0.4%). As the amount of shell powder was increased, the L and b values (Hunter's color) increased. The pH, turbidity, and water absorption also increased as the amount of shell powder was increased. However, when the shell powder content exceeded 0.3%, the hardness, chewiness, springiness, and tension tended to decrease below acceptable levels. This might be because the shell powder inhibited network formation. The textural properties and pH value of rice noodles containing 0.2% shell powder were similar to those of the wheat noodles. This suggests that 0.2% shell powder may be the optimal amount to add to rice noodles when used as the alkaline reagent.

• Journal of Practical Agriculture & Fisheries Research
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• v.23 no.1
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• pp.117-128
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• 2021

The skeletal muscle development of Hanwoo steer has been processed in the prenatal and postnatal periods. Bovine satellite cell located in perimysium of muscle tissues has differentially distributed in peripheral tissues. The study of postnatal development of satellite cells can help understand the genetic and functional regulation of meat characteristics. Factors affecting muscle size increase are related to the accumulation of DNA or synthesis of RNA proteins. In this study, we observed muscle development and differentiation after culturing bovine satellite cells derived from longissimus dorsi and semimembranosus regions of Hanwoo muscle tissue. In addition, RNA sequencing data were analyzed for differentially expressed genes (DEG) involved in intracellular muscle development and growth. The DEG of the two muscle tissues were compared according to 1day, 2day, 4day, and 7day. The overall gene expression level was confirmed by the heat map. Gene Ontology (GO) classification method was used to compare the expression level of gene groups affecting LD and SM development. The histology of GO was consistent with the time-cause change of LD and SM cell morphology. SM showed more active skeletal muscle development than LD. Even within the same time, SM expressed more genes than LD, thus synthesizing more muscle fibers

• Pediatric Infection and Vaccine
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• v.5 no.2
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• pp.245-257
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• 1998

Purpose : Although hepatitis B vaccine has been available to general population in Korea since 1983, it was difficult to compare various types of hepatitis B virus(HBV) vaccines primarily due to the differences in vaccination schedule, dosage, test methods and seropositive antibody level. In this study we reviewed the results of previous studies published in Korea, which include antibody positive rates and antibody titers of various vaccines, and examined the immunogenicity of these HBV vaccines. Methods : Studies published in medical journals, university journals concerning antibody positive rates following hepatitis B vaccination were reviewed. Inclusion criteria were those studies in which seroprotective antibody rate of 10mIU/mL or the sample ratio unit of 10 RU were used as the cut-off value and in which the test methods were RIA or ELISA. Exclusion criteria were; 1) unclear or inconsistent vaccine dosage, 2) no record of antibody titers or seroconversion rate, 3) no defined antibody rate or ratio for positive rating and 4) the vaccination schedule other than 0-1-2 months or 0-1-6 months. Results : 23 out of 52 studies were subjected for the review for seroconversion rates. 1) As for the immunogenicity in each age group, the seroconversion rates of Hepaccine(Cheil Jedang) were 85.1% in infants, 83.3% in children and 62.7% in adults, indicating higher rates in infants and children compared to adults(P<0.01). The seroconversion rates of Hepavax(Korea Green Cross) were 84.7%, 81.1% and 90.8%, indicating higher rates in infants and adults compared to children(P<0.01). 2) The seroconversion rate of Hepavax was 85.6% with 0-1-6 mo. schedule, 78.5% with 0-1-2 mo. schedule with a statistically significant difference(P<0.01). 4) There was no difference of seroconversion rates between the two doses of Hepavax, $5{\mu}g$ and $10{\mu}g$ in infants and children. 5) In adults the seroconversion rates were 62.7% with Hepaccine, 90.8% with Hepavax, and 94.8% with Engerix-B(SmithKline Beecham). Conclusion : In Korea, the incidence of chronic hepatitis B is high and changing the schedule in vaccination cannot contribute to the increase of the serocoversion rate. And in order to maximize immunogenicity, more effective vaccines as well as more proper vaccination methods should be used.

• Food Science of Animal Resources
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• v.23 no.2
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• pp.172-179
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• 2003

This study was carried out to find the preventive medical and therapeutic effects of Sarcodon asparatus on adult disease by employing several biological and biochemical assays. Nitrate scavenging ability(NSA) of Sarcodan asparatus extracts was displayed up to 99.9% at pH 1.2 in a dose-dependent manner. They also had 90.4% electron donating ability(EDA) at the concentration of 0.1 mg/mL. Extracts of Sarcodon asparatus were also able to function as a powerful antioxidant at all concentrations(0.01∼l.0 mg/mL). Furthermore, we observed that 1 mg/mL concentration of the extracts was more powerful than BHT, With respect to fibrolytic activity, Sarcodon asparatus showed 1,843.8 unit/g, which was higher than streptokinase(1,189 unit/g). The inhibitory effects of the extracts on angiotensin converting enzyme, measured by the normal and pretreatment methods, were 53 and 58%, respectively. We also performed cytotoxicity effect of Sarcodon asparatus extracts on a various cancer cell lines. The growth inhibitory effects of the extracts(5.0 mg/mL) on A549, HeLa, AGS, and SK-Hep-1 cells were 78.9, 55.3, 69.0, and 42.5 %, respectively. Interestingly, Sarcodon asparatusextracts induced mutation on Salmonella typhimurium TA98 and TA100 when Ames test was done.