• Title/Summary/Keyword: 대사공학

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System for Repeated Integration of Various Gene Expression Cassettes in the Yeast Chromosome (효모염색체내에 다양한 유전자발현 cassette의 반복적 integration을 위한 system 구축)

  • Kim, Yeon-Hee
    • Journal of Life Science
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    • v.28 no.11
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    • pp.1277-1284
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    • 2018
  • In this study, a repeated yeast integrative plasmid (R-YIp) harboring Cre/loxP system was constructed to integrate various gene expression cassettes into the yeast chromosome. The R-YIp system contains a reusable selective marker (CgTRP1), loxP sequence, and target sequence for integration. Therefore, many gene expression cassettes can be integrated into the same position of the same yeast chromosome. In the present study, several model enzymes involving xylan/xylose metabolism were examined, including endoxylanase (XYLP), ${\beta}$-xylosidase (XYLB), xylose reductase (GRE3) and xylitol dehydrogenase (XYL2). Efficient expression of these genes was obtained using two promoters (GAL10p and ADH1p) and various plasmids (pGMF-GENE and pAMF-GENE plasmids) were constructed. The XYLP, XYLB, GRE3, and XYL2 genes were efficiently expressed under the control of the GAL10 promoter. Subsequently, R-YIps containing the GAL10p-GENE-GAL7t cassette were constructed, resulting in pRS-XylP, pRS-XylB, pRS-Gre3, and pRS-Xyl2 plasmids. These plasmids were sequentially integrated into chromosome VII of a Saccharomyces cerevisiae strain by repeated gene integration and selective marker rescue. These genes were integrated by the R-YIp system and were stably expressed in the yeast transformants to produce active recombinant enzymes. Therefore, we expect that the R-YIp system will be able to overcome current limitations of the host cells and allow selective marker selection for the integration of various genes into the yeast chromosome.

Effect of extraction method on quality characteristics of the carrot juice (주스착즙 방식에 따른 당근 주스의 품질 특성 변화)

  • Park, Hye-Jung;Kim, Ji-Youn;Lee, Song Min;Kim, Hee Sook;Lee, Sang-Hyeon;Lee, Mun Hyon;Jang, Jeong Su
    • Korean Journal of Food Science and Technology
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    • v.51 no.4
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    • pp.369-378
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    • 2019
  • This study aimed to compare the quality characteristics of carrot juice based on different extraction methods such as centrifugation, single gear, and twin gear methods. Juice quality was evaluated based on extraction yield, nutritional components, and cloud stability. Twin gear extraction resulted in the highest extraction yield, and the highest mineral content. In addtion, ${\beta}$-carotene level higher than the recommended daily intake was obtained only in the carrot juice prepared using twin gear extraction of 100 g carrots. The minimum particle size was observed in twin gear extraction, followed by single gear extraction and centrifugation method. Therefore, twin gear extraction was selected as the optimal method, and changes in the antioxidant and metabolic activity of carrot juice were investigated using this method. Consequently, the carrot juice showed a higher lipid peroxidation inhibition rate than ${\alpha}$-tocopherol (1 mg/mL), and angiotensin I-converting enzyme (ACE) inhibitory activity was increased upon digestion.

An overview of the regulatory effect of vitamin D supplementation on atopic dermatitis (비타민 D의 기능성: 아토피피부염의 조절에 미치는 영향 연구)

  • Sung, Dong Eun
    • Korean Journal of Food Science and Technology
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    • v.53 no.2
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    • pp.139-148
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    • 2021
  • Atopic dermatitis is a chronic, recurrent, inflammatory skin disease that is a well-known allergic disease with severe itching, making daily life difficult. Since the immunomodulatory action of vitamin D has been reported, several researchers have attempted to determine the correlation between vitamin D and atopic dermatitis. In this review, 41 articles meeting the inclusion criteria were selected and reviewed from the articles published to date. Several studies have reported that low vitamin D levels are associated with the onset of atopic dermatitis and severe atopic dermatitis, but the opinions remain conflicting. Similarly, there are conflicting opinions on the improvement effect of oral vitamin D supplementation on atopic dermatitis, but some possibilities have been suggested. To apply vitamin D as a therapeutic agent for atopic dermatitis, a more systematically designed experiment should be conducted, and an appropriate intake dose for an immunomodulatory function should be obtained.

Current Perspectives on the Effects of Plant Growth-promoting Rhizobacteria (식물생장촉진 근권미생물의 영향에 대한 연구 현황 및 전망)

  • Le, Thien Tu Huynh;Jun, Sang Eun;Kim, Gyung-Tae
    • Journal of Life Science
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    • v.29 no.11
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    • pp.1281-1293
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    • 2019
  • The rhizosphere is the active zone where plant roots communicate with the soil microbiome, each responding to the other's signals. The soil microbiome within the rhizosphere that is beneficial to plant growth and productivity is known as plant growth-promoting rhizobacteria (PGPR). PGPR take part in many pivotal plant processes, including plant growth, development, immunity, and productivity, by influencing acquisition and utilization of nutrient molecules, regulation of phytohormone biosynthesis, signaling, and response, and resistance to biotic- and abiotic-stresses. PGPR also produce secondary compounds and volatile organic compounds (VOCs) that elicit plant growth. Moreover, plant roots exude attractants that cause PGPR to aggregate in the rhizosphere zone for colonization, improving soil properties and protecting plants against pathogenic factors. The interactions between PGPR and plant roots in rhizosphere are essential and interdependent. Many studies have reported that PGPR function in multiple ways under the same or diverse conditions, directly and indirectly. This review focuses on the roles and strategies of PGPR in enhancing nutrient acquisition by nutrient fixation/solubilization/mineralization, inducing plant growth regulators/phytohormones, and promoting growth and development of root and shoot by affecting cell division, elongation, and differentiation. We also summarize the current knowledge of the effects of PGPR and the soil microbiota on plants.

Evaluation of Intestinal Immunity Activity by Steam-Heat Treatment and Fermentation of Lactic Acid Bacteria of Fruit and Vegetable Complex Extracts containing Red Ginseng (홍삼함유 과채류 복합 추출물의 증숙열처리 및 유산균 발효에 의한 장관면역 활성)

  • Kim, Hyun Kyoung
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.6
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    • pp.935-941
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    • 2022
  • The purpose of this study was to investigate whether the activity of ginsenoside metabolites and the intestinal immunity antioxidant activity were remarkably improved by lactic acid bacteria fermentation by adding a small amount of ginsenoside to the complex extracts of fruits and vegetables. It was confirmed that the increase in intestinal immunity antioxidant activity due to synergistic effect was observed in the fruit-vegetable extract containing ginsenoside compared to the ginsenoside-only extract or the fruit-vegetable extract. Then, by adding ginsenosides by content, the concentration of ginsenosides that can obtain a synergistic effect according to the fermentation of lactic acid bacteria was determined. As a result, it was confirmed that a synergistic effect was exhibited when lactic acid bacteria were fermented and extracted by mixing ginsenosides in a mass ratio of 3 to 10% with respect to the mass of the fruit-vegetable mixture. As a result, when treated at a concentration of 200 ㎍/ml, the fruit-vegetable complex extract containing ginsenoside metabolites inhibited the generation of NO by about 60% compared to the complex extract containing no ginsenoside, The expression of IL-1β was suppressed by 63%, the expression of IL-6 by 69%, and the expression of TNF-α by 76%, confirming that the intestinal immune antioxidant properties were significantly improved.

Enhanced biosynthesis of artemisinin by environmental stresses in Artemisia annua (환경스트레스 처리에 의한 개똥쑥 artemisinin 생합성 증진)

  • Kyung Woon Kim;Cheol Ho Hwang
    • Journal of Plant Biotechnology
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    • v.49 no.4
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    • pp.307-315
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    • 2022
  • Artemisinin is a secondary metabolite of Artemisia annua that shows potent anti-malarial, anti-bacterial, antiviral, and anti-tumor effects. The supply of artemisinin depends on its content in Artemisia annua, in which various environmental factors can affect the plant's biosynthetic yield. In this study, the effects of different light-emitting diode (LED)-irradiation conditions were tested to optimize the germination and growth of Artemisia annua for the enhanced production of artemisinin. Specifically, the ratio between the red and blue lights in the irradiating LED was varied for investigation as follows: [Red : Blue] = [6 : 4], [7 : 3], and [8 : 2]. Furthermore, additional stress factors like UV-B-irradiation (1,395 ㎼/cm2), low temperature (4℃), and dehydration were also explored to induce hormetic expressions of ADS, CYP, and ALDH1, which are essential genes for the biosynthesis of artemisinin. Quantitative polymerase chain reaction (qPCR) was used to analyze the expression levels of the respective genes and their correlation with the specified conditions. [8 : 2] LED-irradiation was the most optimal among the tested conditions for the cultivation of Artemisia annua in terms of both fresh and dry weights post-harvest. For the production of artemisinin, however, [7 : 3] LED-irradiation with dehydration for six hours pre-harvest was the most optimal condition by inducing around twofold enhancement in the biosynthetic yield of artemisinin. As expected, a correlation was observed between the expression levels of the genes and the contents of artemisinin accumulated.

Biochemical Properties and Application of Bacteriocins Derived from Genus Bacillus (Bacillus속 세균 유래 박테리오신의 특성과 응용)

  • Ji-Young Lee;Dae-Ook Kang
    • Journal of Life Science
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    • v.33 no.1
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    • pp.91-101
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    • 2023
  • Bacteriocins are antimicrobial peptides synthesized on ribosomes, produced by bacteria, that inhibit the growth of similar or closely related bacterial strains. Since the discovery of nisin, many bacteriocins with unique structures and various modes of antibacterial activity have been described, and genes encoding production, secretion, and immunity have been reported. Nisin is one of the bacteriocins applied in cheese, liquid eggs, sauces and canned foods. Many of the bacteriocins of the genus Bacillus belong to lantibiotics, which are modified peptides after translation. Other genus Bacillus also produce many non-lantibiotic bacteriocins. Bacteriocins of the genus Bacillus are sometimes becoming more important because of their broader antibacterial spectrum. Bacteriocins are considered attractive compounds in the food and pharmaceutical industries to prevent food spoilage and growth of pathogenic bacteria. Bacteriocins can be used as biological preservatives in a variety of ways in the food system. Biopreservation refers to extending shelf life and improving safety of foods using microorganisms and/or their metabolites. The demand for new antimicrobial compounds has generated great interest in new technologies that can improve food microbiological safety. Applications of bacteriocins are expanding from food to human health. Today, many researchers are shifting their interest in bacteriocins from food preservation to the treatment of bacteria that cause infections and antibiotic-resistant diseases. This exciting new era in bacteriocin research will undoubtedly lead to new inventions and new applications. In this review, we summarize the various properties and applications of bacteriocins produced by the genus Bacillus.

Trends in Saliva Research and Biomedical Clinical Applications (타액 연구의 최신 지견과 임상 응용)

  • Soyoung Park;Eungyung Lee;Jonghyun Shin;Taesung Jeong
    • 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.

Atmospheric Aerosol Monitoring Over Northeast Asia During 2001 from MODIS and TOMS data (MODIS와 TOMS자료를 이용한 2001년 동북아시아 지역의 대기 에어로졸 모니터링)

  • 이권호;홍천상;김영준
    • Korean Journal of Remote Sensing
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    • v.20 no.2
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    • pp.77-89
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    • 2004
  • The spatial and temporal variations of aerosol optical depth (AOD) over Northeast Asia regions have special importance in the aerosol research for estimation of aerosol radiative forcing parameters and climate change. Aerosol optical and physical properties (AOD and ${\AA}$ngstrom parameter) have been investigated by using Moderate Resolution Imaging Spectroradiometer (MODIS) and Total Ozone Mapping Spectrometer (TOMS) Aerosol Index (AI) to estimate aerosol characteristics over the study region during 2001. Additionally, aerosol characteristics over the Korean peninsular during Aerosol Characteristic Experiment in Asia (ACE-Asia) Intensive Observation Period (IOP) have been investigated by using satellite observations. The results showed that the daily-observed aerosol data indicate seasonal variations with relatively higher aerosol loading in the spring and very low during the winter. The typical Asian dust case showed higher AOD (>0.7) with lower Angstrom exponent (<0.5) and higher AI (>0.5) that is mainly due to the composition of coarse particles in the springtime. Mean AOD for 2001 at 4 different places showed 0.65$\pm$0.37 at Beijing, 0.31$\pm$0.19 at Gosan, 0.54$\pm$0.26 at Seoul, and 0.38$\pm$0.19 at Kwangju, respectively. An interesting result was found in the present study that polluted aerosol events with small size dominated-aerosol loading around the Korean peninsular are sometimes observed. The origin of these polluted aerosols was thought to East China. Aerosol distribution from satellite images and trajectory results shows the proof of aerosol transport. Therefore, aerosol monitoring using satellite data is very useful.

KNU Korean Sentiment Lexicon: Bi-LSTM-based Method for Building a Korean Sentiment Lexicon (Bi-LSTM 기반의 한국어 감성사전 구축 방안)

  • Park, Sang-Min;Na, Chul-Won;Choi, Min-Seong;Lee, Da-Hee;On, Byung-Won
    • Journal of Intelligence and Information Systems
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    • v.24 no.4
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    • pp.219-240
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    • 2018
  • Sentiment analysis, which is one of the text mining techniques, is a method for extracting subjective content embedded in text documents. Recently, the sentiment analysis methods have been widely used in many fields. As good examples, data-driven surveys are based on analyzing the subjectivity of text data posted by users and market researches are conducted by analyzing users' review posts to quantify users' reputation on a target product. The basic method of sentiment analysis is to use sentiment dictionary (or lexicon), a list of sentiment vocabularies with positive, neutral, or negative semantics. In general, the meaning of many sentiment words is likely to be different across domains. For example, a sentiment word, 'sad' indicates negative meaning in many fields but a movie. In order to perform accurate sentiment analysis, we need to build the sentiment dictionary for a given domain. However, such a method of building the sentiment lexicon is time-consuming and various sentiment vocabularies are not included without the use of general-purpose sentiment lexicon. In order to address this problem, several studies have been carried out to construct the sentiment lexicon suitable for a specific domain based on 'OPEN HANGUL' and 'SentiWordNet', which are general-purpose sentiment lexicons. However, OPEN HANGUL is no longer being serviced and SentiWordNet does not work well because of language difference in the process of converting Korean word into English word. There are restrictions on the use of such general-purpose sentiment lexicons as seed data for building the sentiment lexicon for a specific domain. In this article, we construct 'KNU Korean Sentiment Lexicon (KNU-KSL)', a new general-purpose Korean sentiment dictionary that is more advanced than existing general-purpose lexicons. The proposed dictionary, which is a list of domain-independent sentiment words such as 'thank you', 'worthy', and 'impressed', is built to quickly construct the sentiment dictionary for a target domain. Especially, it constructs sentiment vocabularies by analyzing the glosses contained in Standard Korean Language Dictionary (SKLD) by the following procedures: First, we propose a sentiment classification model based on Bidirectional Long Short-Term Memory (Bi-LSTM). Second, the proposed deep learning model automatically classifies each of glosses to either positive or negative meaning. Third, positive words and phrases are extracted from the glosses classified as positive meaning, while negative words and phrases are extracted from the glosses classified as negative meaning. Our experimental results show that the average accuracy of the proposed sentiment classification model is up to 89.45%. In addition, the sentiment dictionary is more extended using various external sources including SentiWordNet, SenticNet, Emotional Verbs, and Sentiment Lexicon 0603. Furthermore, we add sentiment information about frequently used coined words and emoticons that are used mainly on the Web. The KNU-KSL contains a total of 14,843 sentiment vocabularies, each of which is one of 1-grams, 2-grams, phrases, and sentence patterns. Unlike existing sentiment dictionaries, it is composed of words that are not affected by particular domains. The recent trend on sentiment analysis is to use deep learning technique without sentiment dictionaries. The importance of developing sentiment dictionaries is declined gradually. However, one of recent studies shows that the words in the sentiment dictionary can be used as features of deep learning models, resulting in the sentiment analysis performed with higher accuracy (Teng, Z., 2016). This result indicates that the sentiment dictionary is used not only for sentiment analysis but also as features of deep learning models for improving accuracy. The proposed dictionary can be used as a basic data for constructing the sentiment lexicon of a particular domain and as features of deep learning models. It is also useful to automatically and quickly build large training sets for deep learning models.