• Title/Summary/Keyword: strain recovery

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Effect of the amino acid mixture on freeze-drying and preservation of Lactobacillns casei YIT 9018 (아미노산 혼합용액이 Lactobacillus casei YIT 9018의 동결건조 및 저장성에 미치는 영향)

  • 윤성식;이해옥;유주현
    • Microbiology and Biotechnology Letters
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    • v.14 no.5
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    • pp.421-426
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    • 1986
  • This study was attempted to find out effective storage methods of Lactobacillus casei YIT 9018, industrial strain for fermented mil k production, without severe bacterial death and activity deteriorations. The cryoprotective effect of the ammo acid mixture consisting of glycine and DL-g1utamic acid on the test strain were examined and also compared with those other protectants already reported. The apparent protective effect by the amino acid mixture was observed to controls. Both glycine and DL-glutamic acid prevented the freezing death of test strain and his effect of 1. casei YIT 9018 had reached stationary stage in MRS-broth 18h after inoculation. Cells harvested from stationary stage were most resistant to freezing damage. The viability of the test strain was affected by rehydration media and the recovery of viable cells was increased about threefold when amino acid mixture was used for rehydration. The presence of non-fat milk solid (NFMS), sucrose and lactose in amino acid mixture increased viability of the test strain up to 85%. In this case, optimal concentrations of NFMS, sucrose and lactose were 10%, 7.5-10%, 7.5-10%, respectively.

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Lysine Production by Thialysine Resistant Mutant of Candida utilis ( I ) - Isolation of High Lysine Excreting Mutant of Candida utilis - (Candida utilis의 Thialysine 내성맥리주에 의한 Lysine생산 ( I ) -Candida utilis의 Lysine을 생산하는 Thialysine 내성맥리주의 분리-)

  • Bang, Byung-Ho;Seu, Jung-Hwn
    • Microbiology and Biotechnology Letters
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    • v.11 no.3
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    • pp.175-180
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    • 1983
  • Thialysine significantly inhibited the growth of wild type strain Gondida utilis NCYC-359. In the absence of thialysine, the culture reached stationary phase after 24hr, however, in the presence of 0.5% thialysine, the culture reached stationary phase after 40hr, respectively. Effect of amino acid or vitamin was investigated on recovery of the growth of wild type strain from thialysine inhibition. Glycine, methionine, arginine and tryptophan recovered growth inhibition by thialyslne to some extent. However, vitamins were inert. Especially, lysine at one eighth concentration of thialysine recovered almost fully the growth inhibition. Thialysine resistant mutants were induced from the parent strain of Condida utilis NCYC-359 by NTG treatment. Colonies of thialysine resistant mutants were obtained on agar minimal medium supplemented with 0.1-0.5% thialysine. The frequency of thialysine resistant mutants induced by the first mutation was the highest at 0.1% The wild strain produced no appreciable lysine extracellularly. However, almost thialysine resistant mutants excreted appreciably. Lysine excretion increased after repeated mutation. Finally, of the thialysine resistant mutants induced by NTG, Condida utilis TRN-4006 was obtained. This strain excreted lysine (400$\mu\textrm{g}$/$m\ell$) into the medium with a concomitant decrease of lysine in the intracellular pool.

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Parametric Study of Hemming Process and Evaluation of Hem Quality Using Simple Models (간이 모델을 이용한 헤밍 공정 변수 연구 및 헤밍 품질 평가)

  • 최원목;임재규;박춘달;김형종
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2003.10a
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    • pp.113-116
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    • 2003
  • Hem quality can be determined mainly by turn-down and roll-in. Turn-down, that is created by the elastic recovery, can't be easily detected and measured since it is usually as small as 0.03 m. This study is focused on the precise evaluation of the hemming defects through analytical and experimetal approaches, and on the investigation of the influence of process parameters on the final hem quality. Implicit finite element analysis of plane-strain hemming process is performed by using a commercial code ABAQUS/Standard. Experiment and measurement is also carried out for steel and aluminium sheet metals, and the results are compared with those of analysis.

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Effect of cross-linking agents on the properties of copolyetherester elastomer(II) (코폴리에테르에스테르 고무 탄성체의 물성에 미치는 가교제의 효과(II))

  • Jang, Young-Joo;Kim, Hae-Young;Baik, Doo-Hyun
    • Proceedings of the Korean Fiber Society Conference
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    • 2002.04a
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    • pp.301-304
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    • 2002
  • In the prior work,$\^$l)/ we introduced several chemical cross-linking agents in order to improve elastic recovery of copolyetheresters, but we are confronted by two difficulties. The first is that cross-linking agents interfere with crystal growth which acts as a physical interlocking. The second is that strain at breaking decreases with the amount of cross-linking agent. It is considered that the chemical interlocking parts couldn't be deformed like crystalline phase. (omitted)

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Secretory Production of Human Leptin in Bacillus subtilis

  • Jeong, Ki-Jun;Lee, Sang-Yup
    • Journal of Microbiology and Biotechnology
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    • v.10 no.6
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    • pp.753-758
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    • 2000
  • Human leptin is identified as a 16kDa (146 amino acids) protein secreted from adipocytes which influences body weight homeostasis. In order to produce active leptin, the human obese gene coding for leptin was expressed in Bacillus subtilis WB600 strain which is deficient in six extracellular proteases. The recombinant leptin was produced in a culture supernatant, and in a culture supernatant, it was contained as high as 48% for total proteins. After simple purification steps, which consisted of ammonium sulfate precipitation and anion-exchange column chromatography, 2.3 mg of leptin with a purity greater than 95% was obtained from the 0.51 culture with the recovery yield of 38.3%. The purified leptin showed the correct folding structure with one disulfied bond.

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Texture and Microstructure in Aluminum 3003 Sheet During Groove Pressing (Groove Pressing 한 Aluminum 3003 판재의 집합조직 및 미세조직의 변화)

  • Kim H. D.;Huh M. Y.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2001.05a
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    • pp.176-179
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    • 2001
  • A simple cold pressing procedure which allows shear deformations on sheet metals is proposed by designing dies with grooves and applied to aluminum 3003 sheets. shear deformation led to the formation of preferred orientation along <100>//RD, and the effect of initial tortures on the formation of shear textures was also studied Rectangular shaped dislocation cells formed in the deformed microstructure and boundaries of dislocation cells gradually rounded with the increased plastic strain. Upon subsequent annealing textures inherited deformation textures. Recrystallized grains consisted of a large number of fully recovered subgrains with well defined boundaries which persisted even after annealing at a higher temperature.

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Compaction Simulator Study on Pectin Introducing Dwell Time

  • Kim, Hyun-Jo;Venkatesh, Gopi
    • Journal of Pharmaceutical Investigation
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    • v.35 no.4
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    • pp.243-247
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    • 2005
  • Although many scientists have used pectin, its feasibility in terms of tablet manufacturability with a high speed machine has never been evaluated. Therefore, compactibility of different pectin types for large scale tableting operation has been evaluated. The compactibility behavior of powder pectins was studied by a compaction simulator. It was found that pectin on its own does not produce tablets of acceptable quality even at a punch velocity as low as 20 rpm (e.g. low tensile strengths, capping and lamination irrespective of applied compression force). Thus, dwell time was introduced and more hard compact was produced as relaxation time in die increases. It was concluded that frequent structural failure observed in both pectin types was due to lack of plastic deformation, poor compactibility and high elastic recovery.

Separation and Purification of Teicoplanin by Diaion HP-20 and Conacnavalin A Chromatography (소수성 Diaion HP-20및 친화성 Concannvalin A 크로마토그래피를 이용한 Glycopeptide계 항생제 Teicoplanin의 분리 및 정제)

  • 김창진;이재찬;박해룡;박동진;김영배
    • Microbiology and Biotechnology Letters
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    • v.31 no.2
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    • pp.201-204
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    • 2003
  • Glycopeptide antibiotics, teicoplanin was purified from a mutant strain of Actinoplanes teichomyceticus ATCC31121, A. teichomyceticus MSL2211. We developed a simple procedure to separate and purify the teicoplanin from the fermentation broth. Teicoplanin was purified by two-step purification system, hydrophobic adsorption and sugar affinity chromatography in combination with HPLC analysis based on the properties of hydrophobic acyl chain and sugar moiety in teicoplanin. Teicoplanin was separated from the culture broth by Diaion HP-20 and further purified by concanavalin A affinity column chromatography. As an adsorbent resin, Diaion HP-20 in broth eliminated toxic effects on growth, reduced feedback repression of teicoplanin production, and assisted In rapid recovery of teicoplanin. The teicoplanin displayed the final yield of 80% and 95% of purity.

Thermally Stimulated strain Recovery of segmented Polyurethanes (Segment형 폴리우레탄의 열자극변형회복)

  • Kim, Byeong-Gyu;Lee, Sang-Yeop;Kim, Jun-Hyeong;Xu, Mao
    • Korean Journal of Materials Research
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    • v.8 no.1
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    • pp.19-22
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    • 1998
  • polycaprolactone diol(PCL), 4,4'-diphenylmethane diisocyanate(MDI) 및 1,4 butane diol(BD)로부터 segment형 폴리우레탄을 합성하였으며, 이들의 열변형 회복 특성을 조사한 결과 이들 재료들은 전형적인 형상기억 효과를 발휘함을 알 수 있었다. 형상회복온도는 연질성분의 함량 증가와 더불어 증가하였으며, 연질성분의 함량조절로 40-8$0^{\circ}C$의 넓은 범위에서 임의로 조절할 수 있었다.

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A Case of Streptococcus suis Infection Causing Pneumonia with Empyema in Korea

  • Oh, Yoon Jung;Song, Sung Heon
    • Tuberculosis and Respiratory Diseases
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    • v.73 no.3
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    • pp.178-181
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    • 2012
  • Streptococcus suis causes meningitis and sepsis in pigs, but human infection has increased over the past few years in those who are exposed to pigs or raw pork. Most cases have occurred in Southeast Asia, but only two cases have been reported in South Korea, presenting with arthritis and meningitis. Here, we report a rare case of S. suis infection, a 60-year-old sailor, who visited the emergency room presenting septicemia, pneumonia with empyema and meningitis, showed full recovery; however, neurologic sequale of severe cognitive dysfunction was present after the usage of antibiotics and percutaneous drainage. S. suis was isolated from blood and pleural fluid and the strain was susceptible to penicillin and vancomycin. Increased awareness of S. suis infection and prevention are warranted.