• Microbiology and Biotechnology Letters
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• v.17 no.6
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• pp.611-618
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• 1989

Effects of methionine on cephalosporin C(CPC) production in a fluidized-bed bioreactor were investigated using bioparticles of Cephalosporium acremonium. Since methionine was found to be an important metabolic regulator on the synthesis of cephalosporin C, the effects of its concentration in the cuture broth and feeding mode to the bioreactor were studied. It was observed that the presence of initial methionine was essential for higher cephalosporin C production and there existed an optimal content of methionine. Carbon consumption rate also increased significantly under the presence of methionine. Production of cephalosporin C was most active when methionine was exhausted in the broth; however its additional feeding did not enhance the antibiotic production in the fluidized-bed bioreactor as much as expected. It was therfore considered important to feed an optimal content of methionine at the early operating stage for a higher cephalosporin C production in a fluidized-bed bioreactor. An interesting thing to note was that titre of the antibiotic with reused bioparticles was about 2 times higher in the methionine containing medium than that without methionine. Therefore repeated use of bioparticles, with an optimal content of methionine, was believed to be very useful to enhance to process productivity.

• Journal of the korean academy of Pediatric Dentistry
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• v.50 no.1
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• pp.1-12
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• 2023

Function of salivary gland and saliva composition can be an indicator of individual's health status. Recently, saliva has been thought to have a high potential for usage in the biomedical field to diagnose, evaluate, and prevent systemic health due to the technological advances in analyzing and detecting small elements such as immunological and metabolic products, viruses, microorganisms, hormones in saliva. As a diagnostic specimen, saliva has some useful advantages compared to serum. Because of simple non-invasive method, saliva sampling is quite comfort for the patient, and it doesn't require specialists to collect samples. The possibility of infection during the collection process is also low. For this reason, proteins, genetic materials, and various biomarkers in saliva are actively being utilized on studying stress, microbiomics, genetics, and epigenetics. For the research on collecting big data related to systemic health, the needs on biobank has been focused. Regeneration of salivary gland based on tissue engineering has been also on advancement. However, there are still many issues to be solved, such as the standardization of sample collection, storage, and usage. This review focuses on the recent trends in the field of saliva research and highlight the future perspectives in biomedical and other applications.

• Journal of Life Science
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• v.16 no.3 s.76
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• pp.454-458
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• 2006

HSF1 is the heat shock transcription factor in Saccharomyces cerevisiae. S. cerevisiae KNU5377 can ferment at high temperature such as $40^{\b{o}}C$. We have been the subjects of intense study because Hsf1p mediates gene expression not only to heat shock, but to a variety of cellular and environmental stress challenges. Basing these facts, we firstly tried to construct the hsf1 gene-deleted mutant. PCR-method for fast production of gene disruption cassette was introduced in a thermotolerant yeast S. cerevisiae KNU5377, which allowed the addition of short flanking homology region as short as 45 bp suffice to mediate homologous recombination to kanMX module. Such a cassette is composed of linking genomic DNA of target gene to the selectable marker kanMX4 that confers geneticin (G418) resistance in yeast. That module is extensively used for PCR-based gene replacement of target gene in the laboratory strains. We describe here the generation of hsf1 gene disruption construction using PCR product of selectable marker with primers that provide homology to the hsf1 gene following separation of haploid strain in wild type yeast S. cerevisiae KNU5377. Yeast deletion overview containing replace cassette module, deletion mutant construction and strain confirmation in this study used Saccharomyces Genome Deletion Project (http:://www-sequence.standard.edu/group/yeast_deletion_project). This mutant by genetic manipulation of wild type yeast KNU5377 strain will provide a good system for analyzing the research of the molecular biology underlying their physiology and metabolic process under fermentation and improvement of their fermentative properties.

• Journal of Life Science
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• v.27 no.6
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• pp.726-737
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• 2017

Carotenoids are isoprenoids with a long polyene chain containing 3 to 15 conjugated double bonds, which determines their absorption spectrum. They typically consist of a $C_{40}$ hydrocarbon backbone often modified by different oxygen-containing functional groups, to yield cyclic or acyclic xanthophylls. Much work has also been focused on the identification, production, and utilization of natural sources of carotenoid (plants, microorganisms and crustacean by-products) as an alternative to the synthetic pigment which currently covers most of the world markets. Nevertheless, only a few carotenoids (${\beta}-carotene$, lycopene, astaxanthin, canthaxanthin, and lutein) can be produced commercially by fermentation or isolation from the small number of abundant natural sources. The market and demand for carotenoids is anticipated to increase dramatically with the discovery that carotenoids exhibit significant anti-carcinogenic activities and play an important role in the prevention of chronic diseases. The increasing importance of carotenoids in the feed, nutraceutical food and pharmaceutical markets has renewed by efforts to find ways of producing additional carotenoid structures in useful quantities. Because microorganisms and plants synthesize hundreds of different complex chemical carotenoid structures and a number of carotenoid biosynthetic pathways have been elucidated on a molecular level, metabolic and genetic engineering of microorganisms can provide a means towards economic production of carotenoid structures that are otherwise inaccessible. The aim of this article is to review our current understanding of carotenoid formation, to explain the perceived benefits of carotenoid in the diet and review the efforts that have been made to increase carotenoid in certain microorganisms.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.9
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• pp.1045-1052
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• 2017

In this study, a battery of genetic-toxicity studies on corn silk extract with high maysin content were performed according to internationally accepted protocols. In a mutation test using Salmonella Typhimurium TA1535, TA1537, TA98, and TA100, the number of mutant colonies did not significantly increase up to a maximum concentration of $5,000{\mu}g/plate$ in the presence or absence of the S9 metabolic activation system. In the chromosome aberration test using Chinese hamster lung fibroblasts, negative results were observed in the concentration up to $1,250{\mu}g/mL$ of corn silk extract. In the micronucleus test using ICR mice, incidence of polymorphonuclear erythrocytes with a maximum concentration of 2,000 mg/kg corn silk extract did not show any significant difference compared to the negative control group. Based on these results, the test substance, con silk extract, did not influence genotoxicity.

• Journal of Plant Biotechnology
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• v.40 no.4
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• pp.210-216
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• 2013

Efficient regeneration methods and transformation system are a priority for successful application of genetic engineering to vegetative propagated plants such as grape (Vitis labrusca L.). This research is to establish shoot regeneration system from plant explants for 'Campbell Early', 'Tamnara', 'Heukgoosul', 'Heukbosek' using two types of plant growth regulators supplemented to medium. The highest adventitious shoot regeneration rate of 5% was achieved on a medium containing of Murashige and Skoog (MS) inorganic salts and Linsmaier and Skoog (LS) vitamins, 2 mg/L of TDZ and 0.1 mg/L of IBA. Leaf tissue of 'Campbell Early', was co-cultivated with Agrobacterium strains, LBA4404 containing the vector pBI121 carrying with CaMV 35S promoter, gus gene as reporter gene and resistance to kanamycin as selective agent, the other Agrobacterium strains, GV3101 containing the vector pB7 WG2D carrying with mPAP1-D gene. mPAP1-D is a regulatory genes of the anthocyanin biosynthetic pathway. 'Campbell Early' harboring mPAP1-D gene was readily able to be selected by red color due to anthocyanin accumulation in the transformed shoot. These results might be helpful for further studies to enhance the transformation efficiency in grape.