• The Korean Journal of Food And Nutrition
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• v.17 no.1
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• pp.8-17
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• 2004

The effect of chlorella extract on the growth and acid production of yoghurt starter was investigated in order to prepare the yoghurt added with chlorella extract. The various levels of chlorella extract powder were added to skim milk medium and the medium was fermented by single or mixed culture of 4 types of lactic acid bacteria such as Streptococcus thermophilus, Lactobacillus acidophilus, Lactobacillus casei, and Lactobacillus bulgaricus. The changes in acid production(pH, titratable acidity) and number of viable cells of the medium during fermentation in skim milk added with chlorella extract powder have determined. When chlorella extract powder was added to skim milk medium at the levels of 0.5%, 1.0%, 2.0%, and 3.0%, the addition of 0.5% chlorella extract powder with the single culture of Str. thermophilus, Lac. casei, and Lac. bulgaricus showed the highest number of viable cell counts after 9 hours incubation. And also all single cultures of the yoghurt starter produced the higher amounts of acid with the addition of 0.5% chlorella extract powder. When chlorella extract powder was added to the medium at the levels of 0.25%, 0.5%, 1.0%, and 2.0%, the addition of lower lever(0.25∼0.5%) of chlorella extract powder with the mixed culture of the lactic acid bacteria showed more the acidity of pH and the number of viable cell counts. Among the treatments tested, the addition of 0.25% chlorella extract powder with the mixed culture of Str. thermophilus and Lac. casei produced the highest number of viable cell counts after 12 hours incubation. Therefore it was suggested to manufacture the yoghurt with the addition of 0.25% chlorella extract powder and the inoculation of mixed culture of Str. thermophilus and Lac. casei for on the stimulation of growth of the yoghurt starter.

• Journal of Microbiology and Biotechnology
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• v.6 no.4
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• pp.295-298
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• 1996

Under glutamine-limited condition, $2\times10^6$ (viable cells/ml) of maximum cell density and 13.5 ($\mu g$/ml) of tissue-type Plasminogen Activators (tPA) production were maintained by spike feeding fresh medium in fed-batch cultivation of human recombinant melanoma cells. It showed that tPA production was much seriously affected than cell growth according to initial glutamine concentrations. Above 3.4 (mmol/I) of glutamine concentration both cell growth and tPA production were not much affected by increasing initial glutamine concentration. Glutamine depleted situation was occurred at latter periods of batch and fed-batch cultivations below 5.4 (mmole/I) of initial glutamine concentration. It also showed that maximum glutamine consumption and ammonia evolution rates were closely related to initial glutamine concentrations. Maximum specific tPA production rate was estimated as $8.1\times19^{-6}$ ($\mu g$/cells/h) at 3.4(mmol/I) of glutamine concentration, which is higher than that from other batch and fed-batch processes.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.121-121
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• 2003

The standard protocol for the production of transgenic mouse from ES-injected embryo has to process via chimera producing and several times breeding steps, In contrast, tetraploid-ES cell complementation method allows the immediate generation of targeted murine mutants from genetically modified ES cell clones. The advantage of this advanced technique is a simple and efficient without chimeric intermediates. Recently, this method has been significantly improved through the discovery that ES cells derived from hybrid strains support the development of viable ES mice more efficiently than inbred ES cells do. Therefore, the objective of this study was to generate transgenic mice overexpressing human resistin gene by using tetrapioid-ES cell complementation method. Human resistin gene was amplified from human fetal liver cDNA library by PCR and cloned into pCR 2.1 TOPO T-vector and constructed in pCMV-Tag4C vector. Human resistin mammalian expression plasmid was transfected into D3-GL ES cells by lipofectamine 2000, and then after 8~10 days of transfection, the human resistin-expressing cells were selected with G418. In order to produce tetraploid embryos, blastomeres of diploid embryos at the two-cell stage were fused with two times of electric pulse using 60 V 30 $\mu$sec. (fusion rate : 93.5%) and cultured upto the blastocyst stage (development rate : 94.6%). The 15~20 previously G418-selected ES cells were injected into tetraploid blastocysts, and then transferred into the uterus of E2.5d pseudopregnant recipient mice. To investigate the gestation progress, two El9.5d fetus were recovered by Casarean section and one fetus was confirmed to contain human resistin gene by genomic DNA-PCR. Therefore, this finding demonstrates that tetraploid-ES mouse technology can be considered as a useful tool to produce transgenic mouse for the rapid analysis of gene function in vivo.

• Journal of Microbiology and Biotechnology
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• v.14 no.5
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• pp.1071-1074
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• 2004

The effect of preadaptation at low temperature on cryoprotection was studied for Lactobacillus paraplantarum C7, a bacteriocin producer isolated from kimchi. L paraplantarum C7 cells in their log growth phase were incubated at $15^\circ{C}$, $10^\circ{C}$, or $5^\circ{C}$ for 2, 4, and 6 h, respectively, before being frozen at $-70^\circ{C}$. After 24 h of freezing, viable cells were counted after brief thawing. The freezing-thawing cycles were repeated three more times. Cells preadapted at $10^\circ{C}$ or $5^\circ{C}$ before freezing survived better than control cells, but preadaptation at $15^\circ{C}$ did not confer cryoprotection. Chloramphenicol addition did not destroy the cryoprotection, indicating that protein synthesis was not required for the development of cryoprotection. SDS-PAGE showed induction of a 6.5-kDa protein, a major cold-shock protein, in preadapted cells.

• Archives of Plastic Surgery
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• v.47 no.4
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• pp.310-316
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• 2020

Background To produce patient-specific nasal implants, it is necessary to harvest and grow autologous cartilage. It is crucial to the proliferation and growth of these cells for scaffolds similar to the extracellular matrix to be prepared. The pore size of the scaffold is critical to cell growth and interaction. Thus, the goal of this study was to determine the optimal pore size for the growth of chondrocytes and fibroblasts. Methods Porous disc-shaped scaffolds with 100-, 200-, 300-, and 400-㎛ pores were produced using polycaprolactone (PCL). Chondrocytes and fibroblasts were cultured after seeding the scaffolds with these cells, and morphologic evaluation was performed on days 2, 14, 28, and 56 after cell seeding. On each of those days, the number of viable cells was evaluated quantitatively using an MTT assay. Results The number of cells had moderately increased by day 28. This increase was noteworthy for the 300- and 400-㎛ pore sizes for fibroblasts; otherwise, no remarkable difference was observed at any size except the 100-㎛ pore size for chondrocytes. By day 56, the number of cells was observed to increase with pore size, and the number of chondrocytes had markedly increased at the 400-㎛ pore size. The findings of the morphologic evaluation were consistent with those of the quantitative evaluation. Conclusions Experiments using disc-type PCL scaffolds showed (via both morphologic and quantitative analysis) that chondrocytes and fibroblasts proliferated most extensively at the 400-㎛ pore size in 56 days of culture.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.493-493
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• 2014

The manufacturing cost of thin-film photovoltics can potentially be lowered by minimizing the amount of a semiconductor material used to fabricate devices. Thin-film solar cells are typically only a few micrometers thick, whereas crystalline silicon (c-Si) wafer solar cells are $180{\sim}300\mu}m$ thick. As such, thin-film layers do not fully absorb incident light and their energy conversion efficiency is lower compared with that of c-Si wafer solar cells. Therefore, effective light trapping is required to realize commercially viable thin-film cells, particularly for indirect-band-gap semiconductors such as c-Si. An emerging method for light trapping in thin film solar cells is the use of metallic nanostructures that support surface plasmons. Plasmon-enhanced light absorption is shown to increase the cell photocurrent in many types of solar cells, specifically, in c-Si thin-film solar cells and in poly-Si thin film solar cell. By proper engineering of these structures, light can be concentrated and coupled into a thin semiconductor layer to increase light absorption. In many cases, silver (Ag) nanoparticles (NP) are formed either on the front surface or on the rear surface on the cells. In case of poly-Si thin film solar cells, Ag NPs are formed on the rear surface of the cells due to longer wavelengths are not perfectly absorbed in the active layer on the first path. In our cells, shorter wavelengths typically 300~500 nm are also not effectively absorbed. For this reason, a new concept of plasmonic nanostructure which is NPs formed both the front - and the rear - surface is worth testing. In this simulation Al NPs were located onto glass because Al has much lower parasitic absorption than other metal NPs. In case of Ag NP, it features parasitic absorption in the optical frequency range. On the other hand, Al NP, which is non-resonant metal NP, is characterized with a higher density of conduction electrons, resulting in highly negative dielectric permittivity. It makes them more suitable for the forward scattering configuration. In addition to this, Ag NP is located on the rear surface of the cell. Ag NPs showed good performance enhancement when they are located on the rear surface of our cells. In this simulation, Al NPs are located on glass and Ag NP is located on the rear Si surface. The structure for the simulation is shown in figure 1. Figure 2 shows FDTD-simulated absorption graphs of the proposed and reference structures. In the simulation, the front of the cell has Al NPs with 70 nm radius and 12.5% coverage; and the rear of the cell has Ag NPs with 157 nm in radius and 41.5% coverage. Such a structure shows better light absorption in 300~550 nm than that of the reference cell without any NPs and the structure with Ag NP on rear only. Therefore, it can be expected that enhanced light absorption of the structure with Al NP on front at 300~550 nm can contribute to the photocurrent enhancement.

• KSBB Journal
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• v.25 no.4
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• pp.303-310
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• 2010

Probiotics beneficially affect the health of the host via various mechanisms in the intestine. Recent developments in probiotic products have mainly been made to maximize probiotic effects in human. In this regard, probiotic products containing doubly coated or encapsulated cells, multi-species probiotics, or high viable cell number (1010 viable cells/gram or more) have been developed and are already available in the market. Until now, the majority of probiotics contain live cells but little attention has been paid to other alternative products such as heat-killed cell or bacteriocin-containing ones, which could have broad applications due to advantages over live cell-based probiotics, such as safety and stability. In addition, genetically engineered lactic acid bacteria could be of great importance in the field of alimentary health if they are carefully designed for biological safety. Although a number of probiotics are marketed by claiming health benefits, regulations for health claims will be more stringent. Therefore sufficient scientific and clinical evidences supporting the safety and efficacy of the potential probiotic strain will be required by the regulatory authority for a health claim, which thus may have a huge impact on the future probiotic market.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.4
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• pp.549-557
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• 2000

Dental caries is a bacterial disease of the dental hard tisssus, characterized by a localized, progressive, molecular disintegration of tooth structure. The action of Leuconostoc lactis 51 about plaque formation and replication by Streptococcus mutans was studied as follows. 1. Lower amount of plaque was produced at the mixed culture of S. mutans and L. lactis 51 than S. mutans alone on the wires in the beaker. 2. Fewer cells of S. mutans were replicated at the mixed culture of S. mutans and L. lactis 51 than S. mutans alone. 3. In M17Y broth, viable cells of S. mutans and L. lactis 51 increased for 12 hours, and decreased for 24 hours. In M17YS broth, viable cells of S. mutans showed time-dependent decrease at mixed culture of S. mutans and L. lactis 51. 4. The culture supernatant of L. lactis 51 didn't inhibit the replication of S. mutans and the formation of artificial plaque. 5. Sucrose and frutose were extracted from the culture supernatant of L. lactis 51 in M17YS broth. These results suggest that L. lactis 51 isolated from the oral cavity inhibits the replication of S. mutans and the formation of artificial plaque.

• Korean Journal of Veterinary Service
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• v.20 no.2
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• pp.143-150
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• 1997

Total viable cells and lactose non-fermenting cells were counted from animal feedstuffs (n=65). And isolation of Gram negative lactose nonfermenting enterobacteria and antibiotics susceptibility of isolates were performed. 1. The ranges of total viable cells / lactose non-fermenters in animal feedstuffs from Korean cattle were counted as 9$\times$$10^4$-1$\times$$10^7$ / 1$\times$$10^2$-6$\times$$10^3$, milking cow as 1$\times$$10^4$-2$\times$$10^8$ / 2$\times$$10^2$-8$\times$$10^3$, pig as 1$\times$$10^4$-1$\times$$10^6$ / 2$\times$$10^2$-6$\times$$10^3$, and chicken as 7$\times$$10^4$-1$\times$$10^9$ / 4$\times$$10^2$-1$\times$$10^5$ cfu/g, respectively. 2. Among the 214 isolates from feedstufs, 87 from Chinan(n=23), 66 from Changsu (n=23) and 61 from Mooju(n=19) were isolated. Of these isolates, 60 from pigs (n: 19), 51 from milking cows(n=15), 45 from chikens(n=11) and 58 from Korean cattle(20) were isolated. 3. Among the 6 genuses of Gram negative lactose nonfermenting enterobacili, Salmonella sp, Y pseudotuberculosis, Ent agglomerans and Sal choleraesuis were frequently encountered. 4. A majority of isolates were sensitive to 19 antibiotics, singly or in combination. These isolates were completely susceptible to Cp, Gm, Imp and Pi, 93% to Ak and To, 73% to Cax and Ts, 66% to Cft and Tim, 46-53% to Caz, Cf and Cz, 33-40% to Am, Azt, Cfz and Ti, and 6% to Cfx, in order, but not susceptible to Crm. 5. Among the antibiotic resistant strains, a total of 23 resistant patterns was noted, and of these Crm 40(18.7%), Am Cf Cfx Cfz Crm Ti 27(12.6%), each of Azt Ctx Crm and Azt Cax Caz Cft Cfx Crm 22(10.3% ) were frequently encountered.

• Journal of Naturopathy
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• v.8 no.2
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• pp.71-77
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• 2019

Purpose: The purpose of this study was to investigate the far-infrared emissivity of patented ocher quilt cotton fabrics and to investigate the microorganisms that survived the washing of cotton fabrics up to 20 times. Methods: A 16S rRNA assay was performed using a far-infrared radiometer and a single colony in which microorganisms grew in nutrient media. Results: The far-infrared emissivity of ocher quilt was 0.902 (90.2%) at 5~20 ㎛ at 40℃, and the radiation energy was 3.63 × 10² w/m². The number of viable cells was 2.0 × 10² cells/ml in ocher duvet cotton fabric, and no viable bacteria found in regular cotton fabric. The base sequence of 16S rRNA of B-2 strain isolated into single colonies was 1,419 bases, and the base sequence of strain A-4 was 1,284 bases. The base sequence of 16S rRNA of these two strains showed high homology with Bacillus spp. The B-2 bacteria showed high homology with 99.0% of the 16S rRNA sequence of B. aryabhattai EF114313 and 99.0% of the A-4 bacteria of B. bingmayongensis AKCS01000011. Consequently the colony strain B-2 finally identified as B. aryabhattai BJ-2 and A-4 as B. bingmayongensis BJ-4 strain. Concusions: Soil Bacillus strains survived in ocher quilt cotton fabric after 20 washing. The material can be useful because quilt cotton fabric emits a large amount of far-infrared and far-infrared radiation energy.