• The Korean Journal of Mycology
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• v.46 no.4
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• pp.459-466
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• 2018

In January 2017, discolored black oat seeds were found in the storage depot of a farmhouse in Jeongeup. Pyrenophora sp. was detected in 45% of the oat seeds surveyed. All Pyrenophora isolates obtained from the seeds were identified as Pyrenophora avenae based on the sequences of internal transcribed spacer (ITS) rDNA regions and glyceraldehyde 3-phosphate dehydrogenase (GPDH) gene and validated by morphological and cultural characterization. A phylogenetic tree constructed using the ITS and GPDH sequences showed that the Korean isolates of P. avenae comprise of four genetically distinct groups. Pathogenicity test validated that the fungus is an infectious agent responsible for discolored black seeds and leaf blotch in oat plants. This is the first study report that P. avenae causes leaf blotch disease of oat in Korea.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.85-85
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• 2003

Human lactoferrin (hLF) is an 80 kDa iron-binding glycoprotein that is expressed in high concentration in milk and in lesser amount in the secondary or specific granules of neutrophils and in plasma, LF is classically considered to be related to the binding, transport, and storage of iron. The transgenic mice carrying the human hLF gene in conjunction with the bovine $\beta$-casein promoter produced the human hLF in their milk during lactation. To screen transgenic mice, PCR was carried out using chromosomal DNA extracted from tail or toe tissues. In this study, stability of germ line transmission and expression of hLF were monitored up to generation Fl7 of a transgenic line. When female mouse of generation F9 was crossbred with normal male, generation F9 to Fl7 mice showed similar transmission rates ($66.0 \pm 12.57%, 42.0 \pm 14.98%, 72.2 \pm 25.45%, 50.0 \pm 16.70%, 65.7 \pm 6.45%, 48.6 \pm 14.65%, 54 1 \pm 18 11%, 57.8 \pm 16.16% and 48.6 \pm 20.66$, respectively), implying that the hLF gene can be transmitted stably up to long term generation in the transgenic mice For ELISA analysis, hLF expression levels were determined with an hLF ELISA kit in accordance with the supplier's protocol. Expression levels of human hLF from milk of generation F9 to Fl3 mice were $ 3.2 \pm 0.69 mg/ml, 3.1 \pm 0.81 mg/ml, 4.6 \pm 1.38 mg/ml, 3.1 \pm 0.42 mg/ml, and 4.5 \pm 1,48 mg/ml$, respectively. These expression levels were lower than that of founder (6.6 mg/$m\ell$) mouse. We concluded that transgenic mice faithfully passed the transgene on their progeny and successively secreted target proteins into their milk through several generations.

• Food Science of Animal Resources
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• v.44 no.4
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• pp.779-789
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• 2024

The effects of irradiation on meat constituents including water, proteins, and lipids are multifaceted. Irradiation leads to the decomposition of water molecules, resulting in the formation of free radicals that can have both positive and negative effects on meat quality and storage. Although irradiation reduces the number of microorganisms and extends the shelf life of meat by damaging microbial DNA and cell membranes, it can also accelerate the oxidation of lipids and proteins, particularly sulfur-containing amino acids and unsaturated fatty acids. With regard to proteins, irradiation affects both myofibrillar and sarcoplasmic proteins. Myofibrillar proteins, such as actin and myosin, can undergo depolymerization and fragmentation, thereby altering protein solubility and structure. Sarcoplasmic proteins, including myoglobin, undergo structural changes that can alter meat color. Collagen, which is crucial for meat toughness, can undergo an increase in solubility owing to irradiation-induced degradation. The lipid content and composition are also influenced by irradiation, with unsaturated fatty acids being particularly vulnerable to oxidation. This process can lead to changes in the lipid quality and the production of off-odors. However, the effects of irradiation on lipid oxidation may vary depending on factors such as irradiation dose and packaging method. In summary, while irradiation can have beneficial effects, such as microbial reduction and shelf-life extension, it can also lead to changes in meat properties that need to be carefully managed to maintain quality and consumer acceptability.

• Korean Journal of Food Science and Technology
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• v.5 no.3
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• pp.169-173
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• 1973

Secondary amines and nitrites in various daily foods have been known as the precursors of potent carcinogenic nitroso compound produced in the human stomach when they were ingested simultaneouly in high concentration. In this report, the amounts and distribution of secondary amines and nitrites in Korean daily foods, kim-chi, fishes, fish eggs, sausages, canned fish foods and fish sauces (salted fish) were studied.Nitrite contents were low in most subjected foods except in sausages. Secondary amines showed low contents in kim-chi, fishes, but high in fish sauces, fish eggs and canned fish foods. The result of this study suggested that the possible formation of carcinogenic nitrosamines during manufacturing, storage and cooking of all Korean foods should be studied.

• Food Science and Preservation
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• v.24 no.7
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• pp.891-897
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• 2017

Apple (Malus domestica) is a climacteric fruit because of its high respiration and ethylene production. Ethylene affects the fruit by decreasing its quality and storability. Md-ACS1 and Md-ACO1 genes are involved in ethylene biosynthesis in apple; the Md-ACS1-2 and Md-ACO1-1 alleles are associated with low ethylene production. We conducted an analysis to study Md-ACS1 and Md-ACO1, and to examine ethylene production and softening rate of fruit at room temperature ($20^{\circ}C$) storage in 'Fuji (FJ)', 'Golden Supreme (GS)', and 5 cultivars of Korean apples ('RubyS (RS)', 'Hongro (HR)', 'Arisoo (AS)', 'Summer King (SK)', 'Greenball (GB)'). The result showed that an increase in the number of the alleles (ACS1-2, ACO1-1) decreased the ethylene production and softening rate. The presence of ACS1-1/1, ACO1-1/2 was confirmed in GS and the highest ethylene production and softening rate was observed. Ethylene production and softening rate of SK and GB expressing ACS1-1/2, ACO1-1/2 were higher than that of HR and AS, expressing ACS1-2/2, ACO1-1/2, but lower than GS. FJ with ACS1-2/2, ACO1-1/1 showed the lowest ethylene production and softening rate among all cultivars except RS. The Md-ACS1 and Md-ACO1 DNA markers could potentially be used to estimate storability and applied in marker assisted selection the improve the efficiency of apple breeding.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.3
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• pp.227-231
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• 2004

A total of 219 polymerase chain reaction tests of genetically modified (GM) DNA sequences in soybean seeds and soybean sprouts were conducted during 2000-2001. No CM gene was found in 96 tests of soybean seeds. However, either a functional CP4EPSPS gene or the 355 promoter gene was found three times in 2000 and eight times in 2001, in between 0.01 and 0.17％ of soybean spout products, in 123 tests. Since the amount of GM genes was much less than the threshold limit of 3％, none of the 11 positive soybean-sprout samples needed to be libeled GM crops. Of these, seven sprout samples were from domestic seeds and four were from seeds imported from China. To find the contamination route, the raw materials, seed surface, floor of the storage room, area around the selection machine, surface of the packaging film and corn powder used in the package were tested. The 35S promoter gene was detected in only two samples of the corn powder (0.1％). Although we could not find the cause of the GM contamination, the sprout package film is one possibility. In total,8.9％ of the soybean sprout tests were GM positive, but the amounts were much less than the threshold of 3％. This means that there are frequent false-positives and these would threaten the sprout industry if GMO were decided qualitatively. Food companies should make their safety data available to the public and make an effort to address people's concerns about GM food more openly. In addition, there is a need to establish a quantitative test for GM genes in sampled water and a sampling method for raw materials.

• Microbiology and Biotechnology Letters
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• v.39 no.2
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• pp.133-139
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• 2011

In this study, we determined the changes in microbial numbers in solar salts according to the manufacturing process and storage duration. The salt samples were harvested from salt farms in Shinan (area 2) and Yeonggwang (area 1). They were serially diluted ten-fold and then placed on 4 kinds of cultivable media (mannitol salt agar, eosin methylene blue, plate count agar, and trypticase soy agar). After incubation, we obtained 62 halophilic isolates from the salt samples. Coliform and general bacteria were not detected in all salt samples. By 16S rRNA sequencing analysis, we found 12 kinds of halophilic bacteria belonging to the genera Halobacillus, Halomonas, Bacillus, Idiomarina, Marinobacter, Pseudoalteromonas, Vibrio, Salinivibrio, Virgibacillus, Alteromonas, Staphylococcus and some un-known stains. In our study, we discovered two novel species that have a 16S rDNA sequence similarity below 97%.

• Journal of Plant Biotechnology
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• v.34 no.4
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• pp.277-283
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• 2007

Embryogenic calluses derived from shoot apical meristem explants of sweetpotato were subjected to particle bombardment to generate transgenic plants for antisense expression of cDNAs encoding two different AGPase small subunit (ibAGP1 and ibAGP2). Plants were generated via somatic embryogenesis. PCR and Southern analysis demonstrated that the incorporation of ibAGP1 and ibAGP2 into the genome in an antisense orientation. Immunoblot analysis confirmed reduced levels of AGPase small subunit in transgenic plant leaves. Plants with both ibAGP1 and ibAGP2 produced a lower level of the protein than plants with ibAGP1 alone. iodine test demonstrated that transgenic plant leaves and storage root accumulated reduced amounts of starch. Iodine staining of leaf tissues indicated that transgenic plants accumulated less amount of starch than control. In accordance with western blot analysis, plants with both ibAGP1 and ibAGP2 accumulated a lower amount of starch than plants with ibAGP1 alone. Both transgenic plants exhibited a severely retarded growth, resulting in bare survival. It is suggested that disrupted expression of the gene encoding AGPase small subunit is lethal to the growth of sweetpotato contrast to other species including potato.

• Korean Journal of Food Science and Technology
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• v.40 no.6
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• pp.669-673
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• 2008

For the development of a biological control method against B. cereus in cheonggukjang, 20 Bacillus spp. were isolated from the naturally fermented baektae and heuktae cheonggukjang, identified by using 16S rDNA sequences. Among the isolated strains, Bacillus sp. SC-8 was selected using the B. cereus lawn cell assay as an antagonistic microorganism against B. cereus. The culture medium of Bacillus sp. SC-8 after 24 hr of incubation at $37^{\circ}C$ also evidenced a high level of antagonistic activity. In cheonggukjang fermented with the mixed culture of Bacillus sp. SC-8 and B. cereus, antagonistic effect against B. cereus was maintained during the fermentation of cheonggukjang, while its effect was reduced during storage at $4^{\circ}C$ due to the decrement of cell population of Bacillus sp. SC-8. In Bacillus sp. SC-15, which was utilized a control, antagonistic activity against B. cereus was not demonstrated on the lawn cell plate assay and culture medium, but its effects were detected in cheonggukjang. Therefore, the production of antagonistic substances of Bacillus spp. depends on the fermentative environment.

• Journal of Life Science
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• v.25 no.1
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• pp.16-20
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• 2015

During the storage of these two species in a large conservation tank, fertilized eggs were collected and the offspring were raised. During culturing of the offspring, individuals with mixed characteristics of these two species were observed, and 96 individuals were randomly tested using microsatellite markers applicable to both species. Among the 96 individuals, 15 individuals with mixed morphological characteristics were confirmed to be hybrids showing both of genotypes red seabream and blackhead seabream. Additionally, based on sequence analysis of mitochondrial cytochrome oxidase subunit 1 (mtDNA CO1), 81 showed 99% nucleotide sequence identity to that of black sea bream, and the remaining 15 individuals showed over 99% sequence identity to that of red seabream. So, hybrids were produced by female red seabream and male blackhead seabream. These results suggest that hybrids may form in nature between these two species if their habitats overlap due to the influence of humans or global climate change.