• Title/Summary/Keyword: minimal medium

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Degradation of Bisphenol A and Removal of Its Estrogenic Activity by Two Laccase Transformants of Irpex lacteus (기계충버섯 형질전환체를 이용한 비스페놀 A의 분해와 에스토로겐 활성 제거)

  • Kim, Yun-Jung;Song, Hong-Gyu;Choi, Hyoung-T.
    • Korean Journal of Microbiology
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    • v.44 no.3
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    • pp.199-202
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    • 2008
  • A white rot fungus Irpex lacteus produced lignin degrading enzymes, which showed degrading activity against various recalcitrant compounds. However, laccase, one of the lignin degrading enzymes, was too low to be assayed by spectrophotometry using o-tolidine as the chromogenic substrate in this fungus under various culture conditions. A laccase expression vector was constructed using a cDNA from Phlebia tremellosa with the constitutively expressed promoter of glyceraldehydes-3-phosphate dehydrogenase gene, and introduced into I. lacteus by the restriction enzyme mediated integration transformation through the protoplast-$CaCl_2$ procedure. Two transformants showed highly increased laccase activities at the early growth phase in the minimal liquid medium, and they not only degraded bisphenol A, a notorious endocrine disrupting chemical, but also removed the estrogenic activity effectively.

Peltier Heating-Assisted Low Temperature Plasma Ionization for Ambient Mass Spectrometry

  • Lee, Hyoung Jun;Oh, Ji-Seon;Heo, Sung Woo;Moon, Jeong Hee;Kim, Jeong-hoon;Park, Sung Goo;Park, Byoung Chul;Kweon, Gi Ryang;Yim, Yong-Hyeon
    • Mass Spectrometry Letters
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    • v.6 no.3
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    • pp.71-74
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    • 2015
  • Low temperature plasma (LTP) ionization mass spectrometry (MS) is one of the widely used ambient analysis methods which allows soft-ionization and rapid analysis of samples in ambient condition with minimal or no sample preparation. One of the major advantages of LTP MS is selective analysis of low-molecular weight, volatile and low- to medium-polarity analytes in a sample. On the contrary, the selectivity for particular class of compound also implies its limitation in general analysis. One of the critical factors limiting LTP ionization efficiency is poor desorption of analytes with low volatility. In this study, a home-built LTP ionization source with Peltier heating sample stage was constructed to enhance desorption and ionization efficiencies of analytes in a sample and its performance was evaluated using standard mixture containing fatty acid ethyl esters (FAEEs). It was also used to reproduce the previous bacterial identification experiment using pattern-recognition for FAEEs. Our result indicates, however, that the bacterial differentiation from FAEE pattern recognition using LTP ionization MS still has many limitations.

A Study on the Problem for discussion about Photogeography (사진지리학의 역할과 범위)

  • Kim, Joo-Hwan
    • Journal of the Speleological Society of Korea
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    • no.74
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    • pp.33-43
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    • 2006
  • The purpose of this study is to scientifically establish the concepts of photogeography, and to present desirable directions for the pursuit of photogeography in Korea. Photogeography is to effectively utilize the documentary and artistic nature of the photo, as an image medium, in the geographic study. The concept of photogeography, along with the term photogeology, is already known widely in foreign countries, and extensive research has been carried out in the field. However, here in Korea, nobody knows the concept of photogeography. Since photogeography has not been systemized as a science, and interest in photography is being minimal, photography, in reality, has in no way been utilized effectively. The photographs used in Photogeography can be classified, according to character, into two major categories, geographic photographs and general photographs, and, according to subject and camera, into still photographs and dynamic photographs. Photographs, such single photographs, slides, air photographs and satellite photographs are in the category of still photographs, while pictures like video and movie pictures are dynamic photographs.

Intraspecific Protoplast Fusion of Cellulolytic Fungus, Penicillium verruculosum (Penicillium verruculosum의 종내 원형질체 융합)

  • Chung, Ki-Chul;Park, Chang-Ryeol;Suk Bai;Chun, Soon-Bai;Kim, Ki-Chung
    • Microbiology and Biotechnology Letters
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    • v.16 no.2
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    • pp.163-167
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    • 1988
  • The conditions for the protoplast fusion of auxotrophic mutants of Penicillium verruculosum were determined. A preparation of commercial enzyme Novozym 234 was used to successfully isolate protoplast from the 20hr old mycelium of P. verruculosum. Under optimal condition, the protoplast yield ranged from 2.4$\times$10$^7$ to 3.0$\times$10$^7$ protoplasts from 400mg of damp mycelia of various auxotrophic mutant strains. The regeneration frequency ranged from 26.6 to 42.4% and the spontaneous reversion frequency of the protoplasts on the regeneration minimal medium was less than 10$^7$. The optimal concentration of PEG 6000 was 20%, and exposure of protoplasts to PEG for 10 min was found to be sufficient for protoplast fusion. Optimal pH of fusion mixture was deter-mined as 5.5 and l0mM of calcium chloride in fusion mixture effectively enhanced the protoplast fusion frequency. Under optimal condition, the fusion frequency between various auxotrophs ranged from 1.8$\times$10$^{-3}$ to 3.5$\times$0$^{-3}$.

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Potential for the Uptake and Removal of Arsenic [As (V) and As (III)] and the Reduction of As (V) to As (III) by Bacillus licheniformis (DAS1) under Different Stresses

  • Tripti, Kumari;Sayantan, D.;Shardendu, Shardendu;Singh, Durgesh Narain;Tripathi, Anil K.
    • Microbiology and Biotechnology Letters
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    • v.42 no.3
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    • pp.238-248
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    • 2014
  • The metalloid arsenic (Z = 33) is considered to be a significant potential threat to human health due to its ubiquity and toxicity, even in rural regions. In this study a rural region contaminated with arsenic, located at longitude $85^{\circ}$ 32'E and latitude $25^{\circ}$ 11'N, was initially examined. Arsenic tolerant bacteria from the rhizosphere of Amaranthas viridis were found and identified as Bacillus licheniformis through 16S rRNA gene sequencing. The potential for the uptake and removal of arsenic at 3, 6 and 9 mM [As(V)], and 2, 4 and 6 mM [As(III)], and for the reduction of the above concentrations of As(V) to As(III) by the Bacillus licheniformis were then assessed. The minimal inhibitory concentrations (MIC) for As(V) and As(III) was determined to be 10 and 7 mM, respectively. At 3 mM 100% As(V) was uptaken by the bacteria with the liberation of 42% As(III) into the medium, whereas at 6 mM As(V), 76% AS(V) was removed from the media and 56% was reduced to As(III). At 2 mM As(III), the bacteria consumed 100%, whereas at 6 mM, the As(III) consumption was only 40%. The role of pH was significant for the speciation, availability and toxicity of the arsenic, which was measured as the variation in growth, uptake and content of cell protein. Both As(V) and As(III) were most toxic at around a neutral pH, whereas both acidic and basic pH favored growth, but at variable levels. Contrary to many reports, the total cell protein content in the bacteria was enhanced by both As(V) and As(III) stress.

Isolation and Characterization of a Crude oil-Degrading Strain, Nocardia sp. H 17-1 (원유 분해균주 Nocardis sp. Hl7-1의 분리 및 특성)

  • 이창호;권기석
    • KSBB Journal
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    • v.11 no.6
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    • pp.654-662
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    • 1996
  • Bacterial strains which degrade crude oil were isolated by liquid culture from oil-spilled soil, and four isolates were selected among them. The strain Hl7-1 was finally selected after testing emulsifying activity and oil conversion rate. The strain Hl7-1 was identified as a Nocardia sp. based on the test for morphological, biochemical and physiological characteristics. It appears to be highly specialized for growth on crude oil in minimal salts medium since it showed preference for oil or degradation products as substrates for growth. It was found that it could grow on at least fifteen different hydrocarbons. The optimum cultural and environmental conditions were seeked. Cell growth and emulsification activity as a function of time were also determined. Crude oil degradation and the reduction of product peak was identified by the analysis of remnant oil by gas chromatography after 3 days of cultivation. Approximately 83% of oil were converted into a form no longer extractable by organic solvents.

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Green Synthesis to Develop Iron-Nano Formulations and Its Toxicity Assays

  • Kulkarni, Smital;Mohanty, Nimain;Kadam, Nitin N.;Swain, Niharika;Thakur, Mansee
    • Journal of Pharmacopuncture
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    • v.23 no.3
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    • pp.165-172
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    • 2020
  • Objectives: In the past few years, herbal medicines have gained popularity over synthetic drugs because of their natural source and minimal side effects which has led to a tremendous growth of phytopharmaceuticals usage. With the development of nanotechnology, it provides alternative approaches to overcome several limitations using nano-formulations. In spite of considerable quantity of antianemic preparations with different iron forms available, currently additives are used and represented in modern pharmaceutical market. Iron deficiency anemia is a major global public health problem which particularly affects pregnant women, children and elderly persons. The situation is complicated because of disadvantages and drug side effects from existing antianemic medicines. There is a great demand for the development of new antianemic preparations. Green synthesis of iron oxide nanoparticles, possess high potential in this field. Methods: Our study focuses on developing green synthesis of iron oxide nanoparticles (IONPs) of 10-50 nm with spherical shape where different dosages were used -1 mg/kg, 10 mg/kg and 100 mg/kg for exposure in Wistar albino female rats for 28 days. The toxicity was assessed using various parameters such as measurements of the rat body and organ mass, hematology, biochemical evaluation and histopathological examinations. Results: No significant differences were observed in body and organ weights. Hematological indices also indicated no significant differences whereas biochemical factors showed increase in levels of direct bilirubin and globulin of medium as well as high dose and SGPT levels were increased only in high dose. The major organs (heart, kidney and liver) showed histopathological alterations in 10 and 100 mg/kg whereas brain showed only in 100 mg/kg. Conclusion: The toxicity of IONPs was found to be more significant when the concentration was increased; however, low doses can be used for further investigation as an antianemic preparation.

Antimicrobial Effect of Tea Extracts from Green Tea, Oolong Tea and Black Tea (녹차, 오룡차 및 홍차 추출물의 항균효과)

  • 김선봉;여생규;안철우;김인수;박영범;박영호
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.24 no.2
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    • pp.293-298
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    • 1995
  • Antimicrobial effect of tea extracts from green tea(steamed, roasted), oolong tea and black tea was investigated. Minimal inhibitory concentration(MIC) of tea extraxcts against 9 well known strains of foodborne pathogenic bacteria such as the Gram positive and Gram negative bacteria was determined at 37$^{\circ}C$. Significant antimicrobial activity was observed in the steamed green tea and the roasted green tea of the water-soluble fraciton, and the steamed green tea of the methanol-soluble fraction, and the steamed green tea, roasted green tea and the oolong tea of the crude catechin fraction. The MIC of these extracts against B. subtillis were 700$\mu\textrm{g}$/ml, 500$\mu\textrm{g}$/ml and 120 $\mu\textrm{g}$/ml, respectively. The crude catechin fraction possessed greater antimicrobial activity than did the other fractions. Among tea extracts, extracts of steamed green tea, roasted green tea and oolong tea showed higher antimicrobial activity than them of black tea. The MIC of the crude catechin fraction obtained from tea extracts against Gram-positive bacteria such as M. Iuteus, B. subtillis and S. mutans were 30~50$\mu\textrm{g}$/ml, 120~240$\mu\textrm{g}$/ml and 120~180$\mu\textrm{g}$/ml, and against Gram-negative bacteri such as e. aerogenes and V. parahaemolyticus were 50~60$\mu\textrm{g}$/ml and 60~70$\mu\textrm{g}$/ml in the broth medium, respectively. Especially, the MIC to Streptococcus mutans which has known as a causative bacteria of a decayed tooth were 120$\mu\textrm{g}$/ml, 140$\mu\textrm{g}$/ml, 180$\mu\textrm{g}$/ml and above 1,000$\mu\textrm{g}$/ml in steamed green tea, roasted green tea, oolong tea and black tea, respectively. Tea extracts had strong growth inhibition activity against foodborne pathogenic and dental bacteria.

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New economical and simple device for intraoperative expansion on small and medium sized soft tissue defects

  • Lee, Jun Won;Park, Seong Hoon;Lee, Seong Joo;Kim, Seong Hwan;Jeong, Hii Sun;Suh, In Suck
    • Archives of Craniofacial Surgery
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    • v.19 no.3
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    • pp.235-239
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    • 2018
  • Intraoperative expansion has been used to cover small to large defects without disadvantages of the conventional tissue expanders. Various materials, for example, expanders and Foley catheters are being used. We introduce a new, convenient and economical device immediately available in the operating room, according to the defect size for intraoperative expansion, with latex gloves or balloons. The retrospective study was done with 20 patients who presented with skin and soft tissue defects. During the operation, expansion was done with latex gloves or balloons inflated with saline through an intravenous line and a three-way stopcock. After the inflation, the glove was removed and skin was covered with expanded tissue. A careful decision was made regarding the inflation volume and placement of the expander according to the defect size. There were no postoperative complications. The skin contracture and tension was minimal with a texture similar to the adjacent tissue. The new intraoperative expansion devices with latex gloves and balloons were cheap and made easily right in the operation room. The reconstruction of small to large sized skin defects can be done successfully, functionally and aesthetically without using expensive commercial materials.

A Study on Measures for Strengthening Local Logistics Company's Competitiveness to Entry into UN (Market) (국내 물류기업의 유엔(시장)진출을 위한 경쟁력 강화방안 연구)

  • Shin, Seok-Hyun;Kwak, Kyu-Seok;Kwon, Moon-Kyu
    • Journal of Navigation and Port Research
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    • v.37 no.4
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    • pp.439-445
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    • 2013
  • Domestic large group logistics company(2nd-party logistics company)has made inroads on large portion of domestic logistics market, whereby the domestic 3rd-party logistics market has been shrinking every year to a level of 30% or so. Global logistics enterprise is steadily increasing 3rd-party global market portion while Local one facing with stagnating growth has very minimal level in the global market share. Fortunately new government strengthening policy change toward local SME and also recent UN's supplying line enlargement to Asia regions are positive factors which make Local SME very positive environments to advance to UN procurement logistics market. On this occasion, the purpose of this paper is to help local logistics company perform successful bidding through study of UN-transportation case and also suggest in SWOT analysis a segmented measure and support policy between Industry, Academia, Government and Institute.