• Title/Summary/Keyword: dual culture

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Suppression of Fusarium Wilt Caused by Fusarium oxysporum f. sp. lactucae and Growth Promotion on Lettuce Using Bacterial Isolates

  • Yadav, Dil Raj;Adhikari, Mahesh;Kim, Sang Woo;Kim, Hyun Seung;Lee, Youn Su
    • Journal of Microbiology and Biotechnology
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    • v.31 no.9
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    • pp.1241-1255
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    • 2021
  • This study was carried out to explore a non-chemical strategy for enhancing productivity by employing some antagonistic rhizobacteria. One hundred eighteen bacterial isolates were obtained from the rhizospheric zone of various crop fields of Gangwon-do, Korea, and screened for antifungal activity against Fusarium wilt (Fusarium oxysporum f. sp. lactucae) in lettuce crop under in vitro and in vivo conditions. In broth-based dual culture assay, fourteen bacterial isolates showed significant inhibition of mycelial growth of F. oxysporium f. sp. lactucae. All of the antagonistic isolates were further characterized for the antagonistic traits under in vitro conditions. The isolates were identified on the basis of biochemical characteristics and confirmed at their species level by 16S rRNA gene sequencing analysis. Arthrobacter sulfonivorans, Bacillus siamensis, Bacillus amyloliquefaciens, Pseudomonas proteolytica, four Paenibacillus peoriae strains, and Bacillus subtilis were identified from the biochemical characterization and 16S rRNA gene sequencing analysis. The isolates EN21 and EN23 showed significant decrease in disease severity on lettuce compared to infected control and other bacterial treatments under greenhouse conditions. Two bacterial isolates, EN4 and EN21, were evaluated to assess their disease reduction and growth promotion in lettuce in field conditions. The consortium of EN4 and EN21 showed significant enhancement of growth on lettuce by suppressing disease caused by F. oxysporum f. sp. lactucae respectively. This study clearly indicates that the promising isolates, EN4 (P. proteolytica) and EN21 (Bacillus siamensis), can be commercialized and used as biofertilizer and/or biopesticide for sustainable crop production.

Dual Culture Inoculation Enhanced Quality of Silage Produced from Leguminous Plants

  • Muthusamy, Karnan;Ilavenil, Soundharrajan;Jung, Jeong Sung;Lee, Bae Hun;Park, Hyung Soo;Choi, Ki Choon
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.41 no.3
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    • pp.176-182
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    • 2021
  • Ensiling is the most preferred technology to preserve the silage quality with high nutrients by the presence of lactic acid bacteria. In this study, lactic acid bacteria RJ1 and S22 were used to make the silages from different leguminous plants such as alfalfa, hairy vetch and red clover. Experimental groups were divided into control and LAB inoculated groups. LAB inoculated group; all legumes treated with a mixture of RJ1 and S22 and made an anaerobic condition for 45d. Without the addition of LAB considered the control group. The results showed that the lactic acid content was higher in all silages in response to LAB treatment and acetic acid content was slightly increased except red clover by LAB compared to control silages. A poor silage quality marker butyric acid was reduced all legume silages in response to LAB inoculation than control silages. The organic acid is closely associated with microbial population experimental silages. We noted that higher LAB and lower yeast were found in the silage in response to LAB treatment. The contents of crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), and total digestible nutrient (TDN) were not altered significantly between control and LAB treated silages. Overall data suggested that the inclusion of additional LAB potentially enhance the silage quality and preserved the nutrients for long period.

Latino Media and Spanish Language Television Broadcasting (라티노 미디어와 스페인어 텔레비전 방송)

  • Lee, Seong hun
    • Cross-Cultural Studies
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    • v.23
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    • pp.243-264
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    • 2011
  • The results of 2000 Population Census explains the context of a series of incidents happening in the Latino television broadcasting market recently. That is, the rapid growth of Latino population so fast as overtaking the Black population has needed media as a means of Latino's own social interests and communication. In this context, the television broadcasting market as a marketing means of capitals targeting for the Latinos has experienced more rapid changes. In other words, there has been some changes in the Latino television broadcasting market which divided by two major networks, Univision and Telemundo. It was 1970s when Latino media started to be considered as an important framework to understand the problems of the Latinos in American society. Experiencing the human rights movement of the 1960s, the Latino communities' sense of identity realized the importance of media as an expression of themselves from the interest on the factors which directly determine the quality of their life such as the immigration, education, health, and employment. The anglo media plays a role in introducing the Latinos and forming the images of the Latinos to the non-Latinos. It can be possible to criticize that the anglo media propagates the unilateral image of the Latinos by the mainstream white society, the stereotyped images of the Latinos. The spanish media targeting for the Latinos has grown continuously, combining the inside needs of forming the identity of the Latinos and communication and outside needs of commercialism. On the other hand, the needs for the programs based on the American Latinos has been increased, along with the increase of the Latino media based on the dual languages or English. This paper reviewed the history of the Latino media briefly, and then examined the relationship between the Latinos and the media through the television broadcasting which influence the Latino's everyday life enormously.

Calcium-Phosphate Crystals Promote RANKL Expression via the Downregulation of DUSP1

  • Choi, YunJeong;Yoo, Ji Hyun;Lee, Youngkyun;Bae, Moon Kyoung;Kim, Hyung Joon
    • Molecules and Cells
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    • v.42 no.2
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    • pp.183-188
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    • 2019
  • Osteoarthritis (OA) is a naturally occurring, irreversible disorder and a major health burden. The disease is multifactorial, involving both physiological and mechanical processes, but calcium crystals have been associated intimately with its pathogenesis. This study tested the hypothesis that these crystals have a detrimental effect on the differentiation of osteoclasts and bone homeostasis. This study employed an osteoblastosteoclast coculture system that resembles in vivo osteoblastdependent osteoclast differentiation along with $Ca^{2+}$-phosphate-coated culture dishes. The calcium-containing crystals upregulated the expression of RANKL and increased the differentiation of osteoclasts significantly as a result. On the other hand, osteoblast differentiation was unaffected. MicroRNA profiling showed that dual-specificity phosphatases 1 (DUSP1) was associated with the increased RANKL expression. DUSP1 belongs to a family of MAPK phosphatases and is known to inactivate all three groups of MAPKs, p38, JNK, and ERK. Furthermore, knockdown of DUSP1 gene expression suggested that RANKL expression increases significantly in the absence of DUSP1 regulation. Microarray analysis of the DUSP1 mRNA levels in patients with pathological bone diseases also showed that the downregulated DUSP1 expression leads to increased expression of RANKL and consequently to the destruction of the bone observed in these patients. These findings suggest that calcium-containing crystals may play a crucial role in promoting RANKL-induced osteoclastogenesis via DUSP1.

Selection of Antifungal Bacteria Burkholderia lata CAB13001 for Control on Red Pepper Anthracnose and Its Control Efficacy in Field (고추 탄저병 방제제 Burkholderia lata CAB13001 선발 및 포장방제 효과)

  • Hahm, Soo-Sang;Kim, Byung-Ryun;Kwon, Mi-Kyung;Han, Kwang-Seop;Park, In-Hee;Seo, Kyung-Won
    • Korean Journal of Organic Agriculture
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    • v.26 no.4
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    • pp.649-660
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    • 2018
  • To control the pepper anthracnose caused by Colletotrichum acutatum, antifungal bacterium strains which was selected among bacterium from natural soil, was tested the antimicrobial activity against various pathogens and its control efficacy on anthracnose disease in the fields. We confirmed that antagonistic activity of CAB13001 strain to pathogens such as Sclerotinia cepivorum, Sclerotinia sclerotium and Botrytis cinerea including Colletotrichum acutatum was remarkable superior with the dual culture method in the artificial medium. In vitro bioassay using the green pepper fruit, CAB13001 strain suppressed the lesion development of Anthracnose disease, and its control value compared to the untreated one was 82.4% on pepper fruit in field test. These results suggested that CAB13001 strain could be a very useful biological control agents to anthracnose disease caused by air born plant pathogens of pepper. By the way, analysis of nucleotide sequence of the gene 16S rDNA, antagonistic bacterium CAB13001 strain used in this study was identified as Burkholderia lata.

Relationship between Acculturative Stress and Mental Health of Multicultural Youths - Focused on the Mediating Effect of Social Support - (다문화 청소년의 문화적응 스트레스와 정신건강의 관계 -사회적 지지 매개 효과 중심으로-)

  • Jang, Seon-Ah;Go, Jeonghun
    • The Journal of the Korea Contents Association
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    • v.21 no.1
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    • pp.662-673
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    • 2021
  • This study is to investigate the mediating effects of social support on the relationship between acculturative stress and mental health of multicultural youth. The results of the study were as follows: 1.573 of the 4th(middle 1) to 6th(middle 3) of the multicultural youth panel were analyzed by AMOS 22.0. First, the acculturation stress of multicultural youths had a positive effect on mental health. Second, acculturation stress of multicultural youths had a negative effect on social support. Third, social support of multicultural youths had a negative effect on mental health. Fourth, social support of multicultural youths had a mediating effect on the effect of acculturation stress on mental health. This result shows that the stress of multicultural youths in the process of adapting to the dual culture negatively affects social support, and this social support has a positive effect on the mental health of multicultural youths.

A Study of Korean-American Consumers' Fashion and Shopping Behavior Based on a Bidimensional Model of Acculturation (이차원적 문화적응이론을 토대로 한 한국계 미국인 소비자들의 패션 및 쇼핑 행동에 관한 연구)

  • Lee Yoon-Jung;Lee Jaeil
    • Journal of the Korean Society of Clothing and Textiles
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    • v.28 no.12 s.138
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    • pp.1545-1553
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    • 2004
  • This study assumes a bidimensional model of acculturation theory in order to understand the acculturation patterns of Korean-Americans and their fashion and shopping behavior. Bidimensional models of acculturation suggest that acculturating individuals may possess the components of both the heritage culture and the new, host culture. A combination of email and paper and pencil surveys was conducted with a convenience sample of Korean-Americans who are living in Seattle and vicinity area (n=108). The questionnaire included questions related to the respondents' and their parents' demographic information, the respondents perceived relationship with their parents, self-reported ethnic identification, ethnicity-related behaviors/attitudes, clothing involvement, shopping motivations, and fashion reference groups. The results support the bidimensional models of acculturation process as opposed to the linear model. Three different groups among Korean-Americans based on their ethnic identification pattern were found: a group with dominant Korean identity(Segregation group), a group with dominant American identity(Assimilation group), and a group with dual identity(Integration group). According to the results of MANOVA and subsequent Duncan and Scheffe tests, the Integration group showed distinct characteristics from Segregation group or Assimilation group, in terms of their ethnicity-related behaviors/attitudes, clothing involvement, shopping motivations, and fashion reference group influence.

Characterization of Bacillus amyloliquefaciens DA12 Showing Potent Antifungal Activity against Mycotoxigenic Fusarium Species

  • Lee, Theresa;Park, Dami;Kim, Kihyun;Lim, Seong Mi;Yu, Nan Hee;Kim, Sosoo;Kim, Hwang-Yong;Jung, Kyu Seok;Jang, Ja Yeong;Park, Jong-Chul;Ham, Hyeonheui;Lee, Soohyung;Hong, Sung Kee;Kim, Jin-Cheol
    • The Plant Pathology Journal
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    • v.33 no.5
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    • pp.499-507
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    • 2017
  • In an attempt to develop a biological control agent against mycotoxigenic Fusarium species, we isolated Bacillus amyloliquefaciens strain DA12 from soil and explored its antimicrobial activities. DA12 was active against the growth of mycotoxigenic F. asiaticum, F. graminearum, F. proliferatum, and F. verticillioides both in vitro and in planta (maize). Further screening using dual culture extended the activity range of strain DA12 against other fungal pathogens including Botrytis cinerea, Colletotrichum coccodes, Endothia parasitica, Fusarium oxysporum, Raffaelea quercus-mongolicae, and Rhizoctonia solani. The butanol extract of the culture filtrate of B. amyloliquefaciens DA12 highly inhibited the germination of F. graminearum macroconidia with inhibition rate 83% at a concentration of $31.3{\mu}g/ml$ and 100% at a concentration of $250{\mu}g/ml$. The antifungal metabolite from the butanol extract was identified as iturin A by thin layer chromatography-bioautography. In addition, volatile organic compounds produced by DA12 were able to inhibit mycelial growth of various phytopathogenic fungi. The volatile compounds were identified as 2-heptanone, 5-methyl heptanone and 6-methyl heptanone by gas chromatography-mass spectrometry (GC-MS) analysis. These results indicate that the antagonistic activity of Bacillus amyloliquefaciens DA12 was attributable to iturin A and volatile heptanones, and the strain could be used as a biocontrol agent to reduce the development of Fusarium diseases and mycotoxin contamination of crops.

Atypical Fruiting Structure Formation of White Fruitbody-Forming Isolates in Ganoderma lucidum (백색자실체를 형성하는 영지 균주의 비정형(非定型) 자실체 구조의 형성)

  • Seo, Geon-Sik
    • The Korean Journal of Mycology
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    • v.27 no.5 s.92
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    • pp.322-327
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    • 1999
  • Five white fruitbodies of Ganoderma lucidum found from two different mushroom farms, and the characteristics of atypical fruiting structure formation of these strains were described. The white fruitbodies were spontaneously generated on Quercus-log during the cultivation. They did not differentiate to the normal fruitbodies with pileus, hymenium, stipe and coloration, and fruitbodies remained non-laccateed even after 3 months. Dikaryotic mycelia isolated from the five white fruitbodies differed from wild-type strains in the mycelial growth rate, colony color, and the capacity of atypical fruiting structure (AFS) formation on agar media. These white mutants readily induced brown colored AFSs on the colonies under ventilation and illumination conditions. Both isolates Gl-010 and Gl-011 that were obtained from a normal and white fruitbody, respectively, did not form AFSs in the dark and/or under black light blue (BLB) light illumination, but induced under the visible light. They required dim light for the AFS formation, and the AFS formation was inhibited up to $0.5{\mu}mol\;m^{-2}\;S^{-1}$ in light intensity. However, the other four isolates induced AFSs even in the dark and BLB illumination, although their parent strain, isolate Gl-030, did not form AFSs under any light conditions. The monokaryotic mycelia derived from basidiospores of the AFSs of the white mutants were compatible with the original culture (dikaryon) on a dual culture.

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Determination of Optimized Growth Medium and Cryoprotective Additives to Enhance the Growth and Survival of Lactobacillus salivarius

  • Yeo, Soyoung;Shin, Hee Sung;Lee, Hye Won;Hong, Doseon;Park, Hyunjoon;Holzapfel, Wilhelm;Kim, Eun Bae;Huh, Chul Sung
    • Journal of Microbiology and Biotechnology
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    • v.28 no.5
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    • pp.718-731
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    • 2018
  • The beneficial effects of lactic acid bacteria (LAB) have been intensively investigated in recent decades with special focus on modulation of the host intestinal microbiota. Numerous discoveries of effective probiotics are driven by a significantly increasing demand for dietary supplements. Consequently, technological advances in the large-scale production and lyophilization are needed by probiotic-related industries for producing probiotic LAB for commercial use. Our study had a dual objective, to determine the optimum growth medium composition and to investigate appropriate cryoprotective additives (CPAs) for Lactobacillus salivarius, and compare its responses with other Lactobacillus species. The one-factor-at-a-time method and central composite design were applied to determine the optimal medium composition for L. salivarius cultivation. The following composition of the medium was established (per liter): 21.64 g maltose, 85 g yeast extract, 1.21 ml Tween 80, 6 g sodium acetate, $0.2g\;MgSO_4{\cdot}7H_2O$, $0.02g\;MnSO_4{\cdot}H_2O$, $1g\;K_2HPO_4$, $1.5g\;KH_2PO_4$, $0.01g\;FeSO_4{\cdot}7H_2O$, and 1 g sodium citrate. A cryoprotective additive combination comprising 10% (w/v) skim milk and 10% (w/v) sucrose supplemented with 2.5% (w/v) sodium glutamate was selected for L. salivarius, and its effectiveness was confirmed using culture-independent methods in the freeze-dried cells of the Lactobacillus strains. In conclusion, the optimized medium enhanced the species-specific cultivation of L. salivarius. On the other hand, the cryoprotective effects of the selected CPA mixture may also be dependent on the bacterial strain. This study highlights the necessity for precise and advanced processing techniques for large-scale production of probiotics in the food and feed industries.