• KSBB Journal
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• v.21 no.5
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• pp.341-346
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• 2006

This study was carried out to establish the optimum condition for cell disruption with a sonificator in the detection of the gram negative bacteria, E. coli for the purpose of developing automatic fluorometer. The efficiency of sonification on the E. coli disruption was greatly dependent on the diameter of sonificator probe tip. The larger sonificator probe diameter showed greater disruption effect. Sonificator probe of 13 mm diameter was the most efficient one for E. coli when sonificated for 20 seconds. The efficiency of the E. coli disruption differed greatly according to the depth of sonificator probe tip sank in the sample solution. The shorter the distance between probe tip end and the bottom of the container, the higher the disruption efficiency. The detection limit of E. coli was $5{\times}10^5CFU/m{\ell}$ when sample was sonificated for 20 seconds with a sonificator probe of 13 mm diameter.

• Food Science of Animal Resources
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• v.26 no.2
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• pp.263-268
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• 2006

Probiotics including Lactobacillus acidophilus, refer to a group of nonpathogenic organisms that protect the human host against gastrointestinal(GI) infections by pathogenic bacteria such as Shiga toxin-producing E. coli(STEC). In the study, the inhibitory effects of STEC ATCC 43894 adhesion by L. acidophilus A4 was investigated on the HT-29 epithelial cells. Specific proteins regulated by cell Iysates of L. acidophilus A4 on STEC ATCC 43894 were also characterized by proteomic analysis. Both cell mass and Iysate of L. acidophilus A4 have exhibited the profound inhibitory activity on the HT-29 cells(about 1.5 log scale reduction). Two-dimensional gel electrophoresis(2-DE) revealed seven proteins that were up-regulated by cell Iysates of L. acidophilus A4 and three proteins that were down-regulated. In addition, three protein spots were only detected in the presence of cell Iysates. These results suggest that inhibitory effects of STEC adhesion by L. acidophilus may be due to the regulation of specific protein of STEC.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2005.05a
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• pp.367-370
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• 2005

본 연구는 김치에서 분리한 유산균과 starter를 첨가하여 제조한 김치의 항암효과가 in vitro 상에서 어떻게 나타나는지 알기위해 실시하였다. 유산균의 균체 자체로는 모든 암세포에 있어서 세포독성을 거의 나타내지 못하였으며, 김치액의 경우는 평균적으로 $30{\sim}40%$정도의 세포독성을 보여주었다. 김치액인 K2가 K1에 비하여 다소 높은 세포독성을 나타내어 첨가된 starter에 따라 약간의 차이를 보여주었다. 유산균의 파쇄액의 경우에는 모든 암세포에서 50%이상의 세포독성을 보였고 대장암 세포인 WiDr과 위암세포인 MKN-45에서 $70{\sim}80%$ 정도의 세포독성으로 암세포 성장 저해에 상당히 효과적으로 관찰되었다. 유산균의 종류에 따른 세포독성을 비교해보면, 혼합 균체 파쇄액인 E3가 단일 균체 파쇄액보다 전반적으로 약간 높은 경향을 보여주었다.

• KSBB Journal
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• v.21 no.5
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• pp.347-352
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• 2006

This study was carried out to establish the optimum condition for cell disruption with a sonificator in the detection of the gram positive bacteria, Bacillus globigii and Streptococcus epidermidis for the purpose of developing automatic fluorometer. The efficiency of sonificator on the Bacillus globigii and Streptococcus epidermidis disruption differed greatly according to the diameter of sonificator probe tip. The larger sonificator probe diameter showed greater disruption. Bacillus globigii was more disruptive than Streptococcus epidermidis. Sonificator probe of the 13 mm diameter was the most efficient one when sample was sonificated for 20 seconds. The detection limits of Bacillus globigii and Streptococcus epidermidis were $10^5CFU/m{\ell}\;and\;5{\times}10^5CFU/m{\ell}$ respectively when samples were sonificated for 20 seconds with a sonificator probe of 13 mm diameter.

• Korean Chemical Engineering Research
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• v.57 no.1
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• pp.85-89
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• 2019

Cell-free protein synthesis utilizes the translational machinery in a cell extract. Unlike the conventional cell-based expression methods, not being affected by the conditions for cell growth, cell-free protein synthesis enables flexible manipulation of individual factors affecting the efficiency protein biosynthesis. However, the high cost and low stability of the energy sources to regenerate ATP have limited the use of cell-free synthesis for large-scale production of recombinant proteins. One of the approaches to address this problem is to use glucose as an alternative energy source to regenerate ATP through the glucose-metabolizing pathways in a cell extract. In this study, in an attempt to improve the efficiency of ATP regeneration by reinforcing oxidative phosphorylation process, we supplemented with cellular lipids to a glucose-fueled reaction mixture for cell-free protein synthesis. As a result of the lipid supplementation, the productivity of chloramphenicol acetyltransferase in a cell-free synthesis system using glucose increased more than 6 fold compared to when the lipid was not supplemented.

• Korean Journal of Microbiology
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• v.54 no.2
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• pp.140-145
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• 2018

The most energy-intensive processes in lipids extraction were the disruption of the cell wall of microalgae. Here, we tried to extract lipids through lysis using virus-infecting microalgae, to compare with those by the other two methods using microwave or ultrasonication. The lipids yield using viral infection was not significantly different from those using ultrasonication and microwave oven. This suggests that the same amount of lipids can be obtained with low energy and costs, as well as that microalgal lipids extraction by chlorella virus infection might provide the price competitiveness in biodiesel production even if it will be applied to mass production facilities.

• Korean Chemical Engineering Research
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• v.51 no.4
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• pp.482-486
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• 2013

Recently, biohydrocarbons are gathering an interest as a new bioenergy due to the versatile applicability. In the present work, a process is proposed for the recovery of lipids from Recombinant E. coli MG1655 which provides longer chain fatty acids. After the growth of the recombinant E. coli, the cells were disrupted by high pressure homogenizer for obtaining intracellular lipids and the resulting solutions were centrifuged and extracted. For the efficient cell disruption with high pressure homogenizer, the pressure higher than 5,000 psi was required. In addition, under the conditions of applied pressure 5,000 to 20,000 psi, 1~3 pass homogenizing was enough for the more than 90% cell disruption. As organic solvents for extraction of lipid, hexane/isopropyl alcohol and ethyl acetate/ethanol systems showed excellent extracting power. With these solvent systems, the 60% lipid could be recovered. Moreover it was found that the extracted lipids contained long-chain fatty acids such as $C_{12}$, $C_{14}$, $C_{16}$ and $C_{18}$.

• KSBB Journal
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• v.16 no.2
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• pp.146-152
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• 2001

To avoid the intrinsic problem of aggregation associated with the traditional solution-phase refolding process, we propose a solid-phase refolding method integrated with expanded bed adsorption chromatography. The model protein used was a fusion protein of recombinant human growth hormone and a glutathione S transferase fragment. It was demonstrated that the EBA-mediated refolding technique could simultaneously remove cellular debris and directly renature the fusion protein inclusion bodies in the cell homogenate with much higher yields and less agregation. To demonstrate the applicability of the method, we successfully tested the three representative types of starting materials, i. e., rhGH monomer, washed inclusion bodies, and the E. coli homogenate. This direct and simplified refolding process could also reduce the number of renaturation steps required and allow refolding at a higher concentration, at approximately 2 mg fusion protein per ml of resin. To the best of our knowledge, it is the first approach that has combined the solid-phase refolding method with expanded bed chromatography.

• Microbiology and Biotechnology Letters
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• v.31 no.4
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• pp.355-361
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• 2003

Immunostimulating effects of lactic acid bacteria as biological response modifier is a subject of growing interest, but the knowledge of these focused on some bacteria as Lactobacillus and Bifidobacterium. In this study, we investigated the effects of Pediococcus pentosaceus EROM101 on the immunostimulating and anti-cancer activity in murine model. P. pentosaceus was mainly found in Kimchi and fermented sea food and is facultatively anaerobic, catalase-netative, gram-positive cocci arranged in pairs, tetrads and clusters. The immunostimulating effects of P. pentosaceus EROM101 were evaluated using IgA production assay of Peyer's patch and proliferation assay of exudated immune cells of Balb/C mice fed P. pentosaceus EROM101 for 3 weeks. The macrophage and splenocyte proliferation were enhanced by orally administrated of P. pentosaceus EROM101. Also, IgA production in Peyer's patch increased by P. pentosaceus EROM101. Anti-cancer activity of P. pentosaceus EROM101 was appeared in Sarcoma 180 tumor-bearing ICR mice. However, this bacterium lysate itself appeared to have noncytotoxic substance against Sarcoma 180 cell in vitro. These results suggested that P. pentosaceus EROM101 reinforce immune system and therefore was revealed to be anti-cancer activity in mice.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.2
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• pp.111-118
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• 2020

Recently, bioenergy research using microalgae, one of the most promising biofuel sources, has attracted much attention. Cell disruption, which can be classified as physical or chemical, is essential to extract functional ingredients from microalgae. In this study, we investigated the cell disruption efficiency of Chlorella sp. using low-frequency non-focused ultrasound (LFNFU). This is a continuously physical method that is superior to chemical methods with respect to environmental friendliness and low processing cost. A flat panel photobioreactor was employed to cultivate Chlorella sp. and its growth curve was fitted both with Logistic and Gompertz models. The temporal change in cell reduction by cell disruption using LFNFU was fitted with a Logistic model. The experimental conditions that were investigated were the initial concentration of microalgal cells, relative amplitude of output ultrasound waves, processing volume of microalgal cells, and initial pH value. The optimal conditions for the most efficient cell disruption were determined through the various tests.