• Biotechnology and Bioprocess Engineering:BBE
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• v.4 no.1
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• pp.21-25
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• 1999

Two low-salt complex media, bactopeptone and desalted yeast extract, were used for high density cultivation of the hyperthermophilic archaeon Sulfolobus solfataricus (DSM 1617). Bactopeptone, which has low mineral ion content among various complex media, was good for cell growth in batch cultures; the maximal cell density in bactopeptone was comparable to that in yeast extract. However, cell growth was rather poor when bactopeptone was added by the fed-batch procedure. Since several vitamins are deficient in abctopeptone, the effect of vitamins on cell growth was examined. Among the vitamins tested, pyridoxine was found to improve the growth rate of S. solfataricus. To reduce the growth inhibition caused by mineral ions, yeast extract was dialyzed against distilled water and then fed-batch cultures were carried out using a fed medium containing desalted yeast extract. Although the concentrations of mineral ions in yeast extract were significantly lowered by the dialysis whether low molecular weight solutes in yest extract are crucial for cell growth, we investigated the effect of trehalose, a most abundant compatible solute in yeast extract, on the growth pattern. Cell densities were increased and the length of the lag phase was markedly shortened by the presence of trehalose, indicating that trehalose plays an important role in the growth of S. solfataricus.

• Journal of Environmental Science International
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• v.31 no.7
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• pp.665-675
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• 2022

The purpose of this study was to provide basic information for judging cultivation suitability by analyzing the growing environment of Zanthoxylum schinifolium habitats in Gyeongnam-do. The site environment, soil environment and community structure were analyzed in habitats of 7 cities and counties. The habitats were distributed in slopes at 87~764 m above sea level. It was found habitats was distributed in the well-drained soil with high content of sand and soil texture of habitats was mainly loamy sand and sandy loam. Bulk density and particle density were 0.89 g/cm³ and 2.65 g/cm³ on average, respectively. The soil had 5.10 of pH, 6.41% of OM content, 0.29% of TN content, 3.84 ppm of available P content, and CEC of 12.3 cmol⁺/kg on average. The habitats were classified into four communities (Z. schinifolium-Lindera erythrocarpa, Castanea crenata-L. erythrocarpa, Pinus densiflora-Z. schinifolium, P. thunbergii-Z. schinifolium by clustering analysis. Ecological niche breadth was highest of 0.885 in site (T VI ongyeong) and lowest of 0.608 in site (Goseong).

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.6
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• pp.313-321
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• 2003

This review summarizes the recent advances in high-density algal cultures in the field of algal biotechnology. Photobioreactor engineering for economical and effective utilization of algae and its products has made impressive and promising progress. Bioprocess engineers have expedited the design and the operation of algal cultivation systems. Many of them in use today are open systems due to cost considerations, and closed photobioreactors have recently attracted a considerable attention for the production of valuable biochemicals or for special applications. For high-density cultures, the optimization of environmental factors in the photobioreactors have been explored, including light delivery, CO$_2$and O$_2$gas transfer, medium supply, mixing and temperature. It is expected that further advanced photobioreactor engineering will enable the commercialization of noble algal products within the next decade.

• Biotechnology and Bioprocess Engineering:BBE
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• v.1 no.1
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• pp.32-35
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• 1996

Amoving aeration-membrane (MAM) bioreactor was employed for the production of 2$\mu$g/mL of tissue type Plasminogen Activator (tPA)in serum free medium from normal human fibroblast cells. This system could maintain high cell density for long periods of steady state conditions in perfusion cultivation. Under normal operating condition, shear stress was as low as 0.65 dynes/$\textrm{cm}^2$ at the agitation speed of 80 rpm. Even though cell density gradually decreased with increasing agitation speed, tPA production increased linearly with increasing shear stress within a moderate range. This culture system allowed production of 2$\mu$g tPA/mL while maintaining a high cell denisty of 1.0$\times$107 viable cell/mL.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.219-222
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• 2000

Physiological changes of Escherichia coli during the fed-batch fermentation process were characterized in this study. Overall cellular protein samples prepared at the different stage of fermentation were separated by 2-dimensional gel electrophoresis (2-DE), and differently expressed 15 proteins, Phosphotransferase enzyme I, GroEL, Trigger factor, ${\beta}$ subunit of ATP synthase, Transcriptional regulator KDGR, Phosphoglycerate mutase 1, Inorganic pyrophosphatase, Serine Hydroxymethyl-transferase, ${\alpha}$ subunit of RNA polymerase, Elongation factor Tu, Elongation factor Ts, Tyrosine-tRNA ligase, DnaK suppressor protein, Transcriptional elongation factor, 30S ribosomal protein S6 were identified using matrix-assisted laser desorption / ionization time-of-flight mass spectrometry (MALDI-TOF MS). When bacterial cells grow to high cell density, and IPTG-inducible heterologous protein is produced, expression level of overall cellular proteins was decreased. According to their functions in the cell, identified proteins were classified into three groups, proteins involved in transport process, small-molecule metabolism, and synthesis and modification of macromolecules.

• KSBB Journal
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• v.6 no.3
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• pp.231-240
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• 1991

Recently, developments of large scale and high density cell culture methods have been the objects of many researches, because the demand of various pharmaceutical products produced by animal cell culture has been rapidly increasing. The cell culture equipment should have the requirements such as sufficient oxygen transfer and mixing, low shear stress and surface tension, and small foaming. In order to develop a proper bioreactor meeting these requirements simultaneously, a perfluorocarbon having high solubility of oxygen was sprayed into the medium as an oxygen carrier instead of air. Also, a new impeller was developed and combined together with the perfluorocarbon spraying system so as to design a new bioreartor for cell cultivation. The new impeller had better characteristics of mixing and oxygen transfer than the paddle and cell-lift impellers based on the same, shear rate. But, it was observed that the volumetric oxygen transfer coefficient of the new bioreactor decreased with increasing cell density during E. coli fermentation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.3
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• pp.369-374
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• 1987

Relationships among root yield, planting density (PD), missing plant rate (MR), leaf area index (LAI) , leaf area per plant(LAP), root weight(RW), number of harvested root(RN) and leaf fall plant rate (LFP) were investigated by survey of white ginseng plantations in Pungi and Geumsan area. In Geumsan PD was about twice than in Pungi but yield was low with high rates of MR and LFP. Yield depended on RN in high PD cultivation while on RW in low PD. The effect of MR on yield was prominent in high PD cultivation. PD showed insignificant negative correlation with yield and no clear relation with MR. RN depended on PD and was especially limited by MR, Yield depended on LAI at harvest time and especially at maximum growth time. LAI was not different between high and low PD area but depended only on RN in high PD and only on LAP in low PD area, and limited by MR in both PD. LAP depended highly on RW and this fact seems to be the very reason that LAI could not increase with the increase of PD. All fields showed the suboptimum LAI.

• Korean Journal of Medicinal Crop Science
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• v.4 no.3
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• pp.265-268
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• 1996

According to the research of the cultivation result of Gardenia for 5 years to investigate its cultivation conditions and problems, the development of the variety with early mature and high yielding is urgent and that of rooted cutting cultivation method by the experiment of rooted cutting, bed soil, growth regulator and cutting period are pressing. The development of cultivation method with planting year, planting density, supplementary period and amounts of supplementary of Gardenia planted on growing field are required and for the disease and insect pest control, the research of the cultivation method with disease and insect pest resistance is ne­eded by auxotrophic fertilizing and organic agricultural method, not by agriltural chemicals.

• Environmental Engineering Research
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• v.19 no.3
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• pp.283-287
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• 2014

Cultivation of microalgae using wastewater exhibits several advantages such as nutrient removal and the production of high valuable products such as lipid and pigments. With this study, two types of wastewater from instant noodle factory; mixed liquor suspended solids (MLSS) and effluents after sedimentation tank were investigated for green microalga Scenedesmus sp. cultivation under laboratory condition. Optimal wastewater dilution percentage was evaluated in 24 wells microplate. MLSS and effluent without dilution showed the highest specific growth rate (${\mu}$) of $1.63{\pm}0.11day^{-1}$ and $1.57{\pm}0.16day^{-1}$, respectively, in which they were significantly (p < 0.05) higher than Scenedesmus sp. grown in BG11 medium ($1.08{\pm}0.14day^{-1}$). Ten days experiment was also conducted using 2000 ml Duran bottle as culture vessel under continuous light at approximately 5000 lux intensity and continuous aeration. It was found that maximum biomass density of microalgae cultivated in MLSS and effluent were $344.16{\pm}105.60mg/L$ and $512.89{\pm}86.93mg/L$ respectively and there was no significant (p < 0.05) difference on growth to control (BG11 medium). Moreover, cultivation microalgae in wastewater could reduce COD in wastewater by 39.89%-73.37%. Therefore, cultivation of Scenedesmus sp. in wastewater from instant noodle factory can yield microalgae biomass production and wastewater reclamation using photobioreactor simultaneously.

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.6
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• pp.349-353
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• 2003

The physiological characteristics of cultures of very high cell mass (e.g. 10g cell mass/L), termed“ultrahigh cell density cultures”is reviewed. A close relationship was found between the length of the optical path (OP) in flat-plate reactors and the optimal cell density of the culture as well as its areal (g m$\^$-2/ day$\^$-1/) productivity. Cell-growth inhibition (GI) unfolds as culture density surpasses a certain threshold. If it is constantly relieved, a 1.0cm OP reactor could produce ca. 50% more than reactors with longer OP, e.g. 5 or 10cm. This unique effect, discovered by Hu et al. [3], is explained in terms of the relationships between the frequency of the light-dark cycle (L-D cycle), cells undergo in their travel between the light and dark volumes in the reactor, and the turnover time of the photosynthetic center (PC). In long OP reactors (5cm and above) the L-D cycle time may be orders of magnitude longer than the PC turnover time, resulting in a light regime in which the cells are exposed along the L-D cycle, to long, wasteful dark periods. In contrast, in reactors with an OP of ca. 1.0 cm, the L-D cycle frequency approaches the PC turnover time resulting in a significant reduction of the wasteful dark exposure time, thereby inducing a surge in photosynthetic efficiency. Presently, the major difficulty in mass cultivation of ultrahigh-density culture (UHDC) concerns cell growth inhibition in the culture, the exact nature of which is awaiting detailed investigation.