• Title/Summary/Keyword: Strain life analysis

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Antitumor Effects of Kluyveromyces marxianus TFM-7 Isolated from Kefir

  • Lee, Hyun-Jung;Nam, Bo-Ra;Kim, Jin-Man;Kim, Ji-Yeon;Paik, Hyun-Dong;Kim, Chang-Han
    • Food Science and Biotechnology
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    • v.16 no.1
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    • pp.133-137
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    • 2007
  • The Strain TFM-7, Which has an antitumor effect, was isolated from Kefir and identified based on analysis using the API 50 CHL kit and 265 rDNA sequencing. Strain TFM-7 was confirmed to belong to the genus Kluyveromyces. Analysis of the 265 rDNA nucleotide sequences found strain TFM-7 to be related to Kluyveromyces marxianus. NRRL Y-828IT. K. marxianus. TFM-7 was cultured with potato dektrose broth medium at $27^{\circ}C$ for 72 hr, and its inhibition effects on the proliferation of seven tumor cell lines and a normal cell line were assessed using the MTT assay. The antitumor effects and growth characteristics of K. marxianus TFM-7 were investigated during a culture period of 7 days. By the $3^{rd}\;day$, K. marxianus TFM-7 showed a dry cell weight 2.39 g/L, a pH of 4.39, an ethanol content of 0.89%, and an inhibition effect on the proliferation of seven tumor cell lines above 50%, except for A-549 tumor cell line. K. marxianus TFM-7 was the most effective at inhibiting the growth of Hep-2 cell line among all tumor cell lines tested. Growth inhibition of a normal cell line, NIH/3T3, was less than 35%, suggesting a decreased level of cytotoxicity toward normal cells. These results indicate that K. marxianus TFM-7 may have used as a yeast strain with antitumor activity.

Degradation of Malic Acid by Issatchenkia orientalis KMBL 5774, an Acidophilic Yeast Strain Isolated from Korean Grape Wine Pomace

  • Seo, Sung-Hee;Rhee, Chang-Ho;Park, Heui-Dong
    • Journal of Microbiology
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    • v.45 no.6
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    • pp.521-527
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    • 2007
  • Several yeast strains degrading malic acid as a sole carbon and energy source were isolated from Korean wine pomace after enrichment culture in the presence of malic acid. Among them, the strain designated as KMBL 5774 showed the highest malic acid degrading ability. It was identified as Issatchenkia orientalis based on its morphological and physiological characteristics as well as the nucleotide sequences of the internal transcribed spacer (ITS) 1-5.8S rDNA-ITS II region. Phylogenetic analysis of the ITS I-5.8S rDNA-ITS II sequences showed that the KMBL 5774 is the closest to I. orientalis zhuan 192. Identity of the sequences of the KMBL 5774 was 99.5% with those of I. orientalis zhuan 192. The optimal pH of the media for the growth and malic acid degradation by the yeast was between 2.0 and 3.0, suggesting that the strain is an acidophile. Under the optimized conditions, the yeast could degrade 95.5% of the malic acid after 24 h of incubation at $30^{\circ}C$ in YNB media containing 2% malic acid as a sole carbon and energy source.

First Report of Soft Rot Induced by Dickeya dadantii on Euphorbia hypogaea in Korea

  • Ismaila Yakubu;Ji Ho Song;Yun Ju Lee;Min A Son;Su Hyeon Han;Hyun Gi Kong
    • Research in Plant Disease
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    • v.30 no.1
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    • pp.95-98
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    • 2024
  • In a survey conducted in March 2023, Euphorbia hypogaea plants cultivated within greenhouses in Yongin, Korea exhibited water-soaked areas near the stem base, close to the soil. Subsequent isolation from diseased E. hypogaea led to the identification of a bacterial strain, designated as CBNUMPBL-103. The isolate was identified as Dickeya dadantii through sequencing of the 16s rRNA and phylogenetic analysis. The pathogenicity of the isolate was confirmed by inoculating it into healthy E. hypogaea, resulting in the manifestation of similar symptoms observed during the survey. The re-isolated strain recovered from inoculated plants showed a similar morphology with the inoculated strain. This is the first documentation of D. dadantii causing soft rot of E. hypogaea in Korea.

Characteristics of Nitrobenzene Degradation by Mycobacterium chelonae Strain NB01

  • Oh, Young-Sook;Lee, Youn-Hee;Lee, Jung-Hyun;Choi, Sung-Chan
    • Journal of Microbiology and Biotechnology
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    • v.13 no.2
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    • pp.309-312
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    • 2003
  • A bacterial strain NB01, isolated from wastewater, was found to utilize nitrobenzene (NB) as the sole source of nitrogen, carbon, and energy. The strain was classified as a member of a high G+C Gram-positive group and identified as Mycobacterium chelonae based on an analysis of its 16S rRNA gene sequence. The strain grew on NB with a concomitant release of about 63% of the total available nitrogen as ammonia, suggesting a reductive degradation mechanism. The optimal pH and temperature for degradation were PH 7.0-8.0 and $30^{\circ}C$, respectively. The cell growth was retarded at NB concentrations above 1.8 mM. The degradation of NB followed Michaelis-Menten kinetics within the tolerance range, and the $K_m$ and maximum specific removal rate for NB were 0.33 mM and $11.04\;h^{-1}$, respectively.

Economic Stress, Marital Conflict, and the Quality of Life under Economic Crisis (경제위기 상황에서의 경제적 스트레스와 부부갈등 및 생활의 질)

  • 이미숙;고선주;권희경
    • Journal of the Korean Home Economics Association
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    • v.38 no.6
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    • pp.117-133
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    • 2000
  • The purpose of this study was to examine the effect of perceived economic stress & marital conflict on the quality of life under economic crisis in Korea. Data were collected from 236 couples during May and June 1998, when the Korean economy was under the control of International Monetary Fund (IMF). Many couples reported the unstability of job and the experience of economic strain events. However, the perceived level of marital conflict and the quality of life were not so bad. Husbands perceived economic stress and quality of life higher than wives did. The path analysis showed gender difference in the perceived economic stress as well as in the indirect effect of economic strain events on the quality of life through economic stress and marital conflict. In addition, family income directly affected the quality of life for husbands, but not for wives.

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Probiotic Potential of Plant-Derived Lactic Acid Bacteria with Antihypertensive Activity (항고혈압 활성을 가진 식물유래 젖산균의 생균제 특성)

  • Lee, Ye-Ram;Son, Young-Jun;Park, Soo-Yun;Jang, Eun-Young;Yoo, Ji-Yeon;Son, Hong-Joo
    • Journal of Environmental Science International
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    • v.25 no.6
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    • pp.789-798
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    • 2016
  • Lactic acid bacteria (LAB) are industrially important microorganisms for probiotics. The recent widespread application of LAB for preparation of functional food is attributable to the accumulating scientific evidence showing their beneficial effects on human health. In this study, we isolated and characterized plant-derived LAB that show angiotensin-converting enzyme (ACE) inhibitory and antioxidant activities. The selected strain K2 was isolated from Kimchi, and identified as Lactobacillus plantarum by 16S rRNA gene analysis. The strain grew under static and shaking culture systems. They were also able to grow in different culture conditions like $25^{\circ}C{\sim}37^{\circ}C$ temperature, 4~10 pH range and ~6% NaCl concentration. L. plantarum K2 was highly resistant to acid stress; survival rate of the strain at pH 2.5 and 3 were 80% and 91.6%, respectively. The strain K2 also showed high bile resistance to 0.3% bile bovine and 0.3% bile extract with more than 74% of survival rate. The cell grown on MRS agar plate containing bile extract formed opaque precipitate zones around the colonies, indicating they have bile salt hydrolase activity. The strain showed an inhibitory activity against pathogenic bacteria such as Escherichia coli, Staphylococcus aureus and Listeria monocytogenes; antibacterial activity was probably due to the lactic acid. The K2 strain showed relatively higher autoaggregation values, antihypertensive and antioxidant activities. These results suggest that L. plantarum K2 could be not only applied as a pharmabiotic for human health but also is also starter culture applicable to fermentative products.

A Study on the Prediction of Fatigue Life in Die (금형의 피로수명 예측에 관한 연구)

  • 여은구
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.8 no.4
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    • pp.87-92
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    • 1999
  • Generally the life of die is limited by fatigue fracture or dimensional inaccuracy originated from wear. In this paper to predict the fatigue life of die the stress and strain histories of die can be predicted by the analysis of elastic-plastic finite element method and the elastic analysis of die during the process analysis of workpiece. Also the stress-life curve of die material can be obtained through experiment. With the above to재 facts we propose the analysis method of prediction fatigue life in die,. In the proposed model the analysis of elastic-plastic finite element method for material is carried out by using ABAQUS. Surface force resulted from the contacting border of the die and workpiece is transformed into the nodal force of die to implement elastic analysis. besides the proposed analysis model of die is applied to extrusion die and forging. die.

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Flavobacterium jocheonensis sp. nov., Isolated from Marine Green Alga Ulva pertusa

  • Choi, Ha Ri;Park, So Hyun;Heo, Moon Soo
    • Journal of Microbiology and Biotechnology
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    • v.29 no.8
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    • pp.1266-1272
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    • 2019
  • A bacterial strain, labeled $UR11^T$, was isolated from green alga Ulva pertusa collected from Jeju Island, Korea. $UR11^T$ was identified as a gram-negative, rod-shaped, motile by gliding and aerobic bacterial strain with yellow colonies on R2A plates. The strain $UR11^T$ grew over at a temperature range of $10^{\circ}C$ to $30^{\circ}C$ (optimally at $25^{\circ}C$), a pH range of 6.0-11 (optimally at pH 7.0) and a Nacl range of 0.5-5% Nacl (w/v). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain $UR11^T$ was a member of the genus Flavobacterium. Strain $UR11^T$ shared close similarity with F. jejuensis $EC11^T$ (98.0%) F. jumunjinense $HME7102^T$ (96.1%), F. haoranii $LQY-7^T$ (95.3%), F. dongtanense $LW30^T$ (95.1%), and F. ahnfeltiae 10Alg $130^T$(94.9%). The major fatty acids (>5%) were $iso-C_{15:0}$ (33.9%), $iso-C_{15:1}$ G (12.4%), $iso-C_{17:0}$ 3-OH (9.0%), $isoC_{16:0}$ (7.0%) and $iso-C_{15:0}$ 3-OH (6.3%). The major polar lipids were phosphatidylethanolamine, seven unknown aminolipids, two unknown aminopolarlipids and two unknown lipids. DNA-DNA hybridization value was 58% at strain $UR11^T$ with F. jejuensis $EC11^T$. Based on phenotypic, chemotaxonomic and phylogenetic evidence, strain $UR11^T$ represents a novel species of the genus Flavobacterium, for which the name Flavobacterium jocheonensis sp. nov. is proposed. The type strain is Flavobacterium jocheonensis is $UR11^T$ (=KCTC $52377^T$ =JCM $31512^T$).

Labrenzia callyspongiae sp. nov., Isolated from Marine Sponge Callyspongia elegans in Jeju Island

  • Park, So Hyun;Kim, Ji Young;Heo, Moon Soo
    • Journal of Microbiology and Biotechnology
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    • v.29 no.12
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    • pp.1969-1974
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    • 2019
  • A Gram-staining-negative, aerobic, light brown pigment bacterium, designated strain CE80T was isolated from marine sponge Callyspongia elegans in Jeju Island, Republic of Korea. Strain CE80T grew optimally at 25℃, in the range of pH 5.0-11.0 (optimum 7.0-8.0), and with 1.0-5.0% NaCl (optimum 1-3% (w/v)). Phylogenetic analysis based on the 16S rRNA gene sequence showed that strain CE80T belonged to the genus Labrenzia and was closely related to L. suaedae YC6927T (98.3%), L. alexandrii DFL-11T (96.6%), L. aggregata IAM 12614T (96.6%) L. marina mano18T (96.5%) and L. alba CECT 5094T (96.2%). The major fatty acids of strain CE80T were C18:1 ω7c, and summed feature. The polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylmonomethylethanolamin, one unidentified aminolipid, one phospholipid and four unidentified lipids. The DNA G+C content of strain CE80T was 55.9 mol%. The major respiratory quinone was Q-10. DNA-DNA relatedness between strain CE80T and L. suaedae YC6927T was 56.1±2.8%. On the basis of physiological and biochemical characterization and phylogenetic and chemotaxonomic analysis, strain CE80T represents a novel species of the Labrenzia, for which the name Labrenzia callyspongiae sp. nov., is proposed. The type strain is CE80T (=KCTC 42849T =JCM 31309T).

A Study on FEM Analysis Method for Life Evaluation of Forging Steel (단조강의 수명평가를 위한 유한요소해석방법에 관한 연구)

  • 허선철;박영철;이동화
    • Transactions of the Korean Society of Automotive Engineers
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    • v.12 no.3
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    • pp.122-129
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    • 2004
  • In plastic working, as working becomes speedy, automatic and working condition deteriorates, the increase of forging working has been remarkable. Therefore, we need the estimation of mold lift in detail, in order to counterplan of effective mold life extension. In this study, on the SKH51, mold steel which is forged by cold working and the KCW1, tool steel of low alloy, we estimated mold life on the base of FEM analysis and investigated mold lift by low cycle fatigue test. Also, this paper suggested a new method of estimation of mold lift.