• Title/Summary/Keyword: Biotechnology industry

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Molecular Characterization of the Levansucrase Gene from Pseudomonas aurantiaca S-4380 and Its Expression in Escherichia coli

  • Jang, Eun-Kyung;Jang, Ki-Hyo;Isaac Koh;Kim, In-Hwan;Kim, Seung-Hwan;Kang, Soon-Ah;Kim, Chul-Ho;Ha, Sang-Do;Rhee, Sang-Ki
    • Journal of Microbiology and Biotechnology
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    • v.12 no.4
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    • pp.603-609
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    • 2002
  • DFA IV is di-D-fructose-2,6':6,2'-dianhydride, consisting of two fructose residues. It can be enzymatically synthesized from levan by levan fructotransferase, and can be used for mineral absorption. Understanding of the structure and composition of levan is important to obtain high-level production of DFA IV. A bacterial strain, Pseudomonas aurantiaca 5-4380, was identified to produce low-branched levan, and the levansucrase gene (lsch) from this bacterium was found to be composed of 1,275 Up coding for a protein of 424 amino acids, with an estimated molecular weight of 47 kDa. The bacterial levansucrase gene was expressed in Escherichia coli DH5${\alpha}$ by its own promoter and lac promoter. The recombinant levansucrase was produced in soluble form with 170U of levansucrase activity from 1-ml E. coii culture broth. The expressed enzyme from the clone showed similar biochemical properties, such as size of active levansucrase, degree of branching, and optimum temperature, with P.aurantiaca 5-4380 levansucrase.

Technical and Strategic Approach for the Control of Cyanobacterial Bloom in Fresh Waters (담수수계에서 남조류 증식억제의 기술적, 전략적 접근)

  • Lee, Chang Soo;Ahn, Chi-Yong;La, Hyun-Joon;Lee, Sanghyup;Oh, Hee-Mock
    • Korean Journal of Environmental Biology
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    • v.31 no.4
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    • pp.233-242
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    • 2013
  • Cyanobacteria (blue-green algae) are not only the first oxygenic organisms on earth but also the foremost primary producers in aquatic environment. Massive growth of cyanobacteria, in eutrophic waters, usually changes the water colour to green and is called as algal (cyanobacterial) bloom or green tide. Cyanobacterial blooms are a result of high levels of primary production by certain species such as Microcystis sp., Anabaena sp., Oscillatoria sp., Aphanizomenon sp. and Phormidium sp. These cyanobacterial species can produce hepatotoxins or neurotoxins as well as malodorous compounds like geosmin and 2-methylisoborneol (MIB). In order to solve the nationwide problem of hazardous cyanobacterial blooms in Korea, the following technically and strategically sound approaches need to be developed. 1) As a long-term strategy, reduction of the nutrients such as phosphorus and nitrogen in our water bodies to below permitted levels. 2) As a short term strategy, field application of combination of already established bloom remediation techniques. 3) Development of emerging convergence technologies based on information and communication technology (ICT), environmental technology (ET) and biotechnology (BT). 4) Finally, strengthening education and creating awareness among students, public and industry for effective reduction of pollution discharge. Considering their ecological roles, a complete elimination of cyanobacteria is not desirable. Hence a holistic approach mentioned above in combination to addressing the issue from a social perspective with cooperation from public, government, industry, academic and research institutions is more pragmatic and desirable management strategy.

Optimization of Cultivation and Storage Conditions on Red Cabbage Seed Sprouts (적양배추 새싹채소의 발아 및 저장 조건 최적화)

  • Baek, Kyeong-Hwan;Jo, Doekjo;Yoon, Sung-Ran;Kim, Gui-Ran;Park, Ju-Hwan;Lee, Gee-Dong;Kim, Jeong-Sook;Kim, Yuri;Han, Bumsoo;Kwon, Joong-Ho
    • Korean Journal of Food Science and Technology
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    • v.45 no.1
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    • pp.13-19
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    • 2013
  • This study was carried out to find the optimal conditions for red cabbage seed sprouts in terms of their physicochemical and sensory qualities by electron-beam irradiation, cultivation and storage using the response surface methodology (RSM). Moisture content ($R^2$=0.9638) was affected by irradiation dose and cultivation time. Total phenolics content ($R^2$=0.9117) was mainly affected by irradiation dose, but carotenoid content ($R^2$=0.8338) was affected in the order of irradiation dose, cultivation time and storage time. Sensory properties were also affected by irradiation dose, and thus scores decreased as irradiation dose increased. The optimum conditions estimated by superimposing total phenolics content and overall acceptance were 2.2-3.8 kGy of the irradiation dose, 3.0-4.0 days of cultivation and 2.0-3.0 days of storage.

Recent Insights into Aeromonas salmonicida and Its Bacteriophages in Aquaculture: A Comprehensive Review

  • Park, Seon Young;Han, Jee Eun;Kwon, Hyemin;Park, Se Chang;Kim, Ji Hyung
    • Journal of Microbiology and Biotechnology
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    • v.30 no.10
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    • pp.1443-1457
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    • 2020
  • The emergence and spread of antimicrobial resistance in pathogenic bacteria of fish and shellfish have caused serious concerns in the aquaculture industry, owing to the potential health risks to humans and animals. Among these bacteria, Aeromonas salmonicida, which is one of the most important primary pathogens in salmonids, is responsible for significant economic losses in the global aquaculture industry, especially in salmonid farming because of its severe infectivity and acquisition of antimicrobial resistance. Therefore, interest in the use of alternative approaches to prevent and control A. salmonicida infections has increased in recent years, and several applications of bacteriophages (phages) have provided promising results. For several decades, A. salmonicida and phages infecting this fish pathogen have been thoroughly investigated in various research areas including aquaculture. The general overview of phage usage to control bacterial diseases in aquaculture, including the general advantages of this strategy, has been clearly described in previous reviews. Therefore, this review specifically focuses on providing insights into the phages infecting A. salmonicida, from basic research to biotechnological application in aquaculture, as well as recent advances in the study of A. salmonicida.

Optimization of Repulping Process of Unsorted ONP for Pulp Mold (I) - Laboratory high consistency pulper - (펄프몰드 제조를 위한 미분류 신문폐지의 펄핑 공정 최적화 (제1보) - 실험용 고농도 펄퍼 이용 -)

  • Ryu, Jeong-Yong;Cho, Byoung-Uk;Kim, Tae-Keun;Park, Dae-Sik;Shin, Eun-Ju;Song, Bong-Keun
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.39 no.4
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    • pp.38-44
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    • 2007
  • In order to utilize unsorted ONP, which contains leaflets (printed coated papers), to produce pulp mold, optimum conditions for a repulping process were investigated with a laboratory high consistency pulper. It was concluded that medium or high consistency pulping is necessary to accelerate the rate of deflaking of unsorted ONP. Considering flake content, fines content and pulping energy, the optimum conditions for the laboratory Helico pulper were 11% of repulping concentration and 3 min of repulping time. The repulping temperature shall be at least $30^{\circ}C$. Aging of paper slows down the rate of de flaking but in an actual pulp molding process its effect could be negligible.