• Korean Journal of Poultry Science
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• v.19 no.2
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• pp.107-112
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• 1992

Sporozoite of Eimeria tenella inoculated into the allantoic cavities of embryonating eggs completed their life-cycle in the chorioallantoic membranes (CAM ) and produced viable oocysts. And the strain continued to adapt to the CAM through the period of the passages. In embryos, the reproduction of the strain, judged by oocyst production increased, but the pathogenicity, judged by mortality of embryo decreased, with increasing numbers of passage in eggs.

• KSBB Journal
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• v.4 no.2
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• pp.74-77
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• 1989

To increase the volumetric productivity a contimuous cell-recycled system was implemented. Cell concentrations between 9.2 and 15.0 g/1 were obtatined in the continuous fermentor study. At a 4% xylose feed and a specific oxygen supply rate(SOSR) of 1.04 g O2.hr-g DCW the ethanol yield was 0.36% at dilution rate. This represented a 26-% increase over that of th batch fermentation.

• Korean Journal of Microbiology
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• v.25 no.1
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• pp.80-85
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• 1987

The aim of the present studies was to analyze the physiological background of ethanol inhibition in Zumomonas mobilis. The experiments were carried out with a number of continuous culture to give steady state concentration of ethanol. The domposition of fatty acids in the cells obtained from various conditions was analyzed and cell viability was also estimated. As results, it was found that vaccenic acid was the mafor fatty acid in the cell of Z. mobilis and the concentration was changed apparently to increase as increasing the concentration of ethanol produced from substrate utilization. Finally it was observed also that cell viability was decreased remarkably at the elevated ethanol concentration. Those changes might play important roles in the ethanol fermentation to give more complex phenomena observed at high concentration of ethanol.

• Journal of Yeungnam Medical Science
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• v.4 no.1
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• pp.17-23
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• 1987

New born rat heart cells were dissociated using trypsin and/or collegenase to elucidate the dissociation efficiency of these two enzymes. And the effect of dimethyl sulfoxide during and immediately after cell dissociation was also investigated to clarify the so-called protective activity of dimethyl sulfoxide on cell performance. The results can be summarized as follows. 1. Cold trypsin 18 hours pretreatment followed by warm collagenase treatment resulted best cell viability and cell yield. 2. Single, warm trypsin treatment gave the poorest result. 3. Dimethyl sulfoxide did not seem to play any protective role during or immediately after rat heart cell dissociation. It had very damaging effect on rat heart cells.

• KSBB Journal
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• v.11 no.5
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• pp.524-528
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• 1996

Bacterial degradation of 4-chloro-2-methylphenoxyacetic acid (MCPA) was studied in column reactors under conditions approximating a fluidized bed system, with granular activated carbon (GAC) as a support matrix. A mixed bacterial culture of MCPA-degrading bacteria was used as an inoculum to develop a biofilm on GAC. Initially, adsorption of MCPA by GAC and blofilm formation on GAC were examined. MCPA degradation was evaluated with a batch and continuous mode of operation of the GAC fixed-film column reactors. In the batch operations, complete degradation of MCPA was achieved during the incubation period. Partial degradation of MCPA occurred in the continuous operations and MCPA degradation was dependent on the feeding rate of MCPA solution.

• KSBB Journal
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• v.4 no.2
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• pp.185-190
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• 1989

Semicontinuous alcohol fermentation of Jerusalem Artichoke by K. fragilis CBS 1555 was performed to investigate the effect of the effective dilution rate and influent sugar concentration to the ethanol concentration and alcohol productivity at steady state. When the time interval for the replacement of fresh influent with fermentation broth was less than or equal to 1 hr, the effective dilution rate was found out to be equal to the specific growth rate. Wash out was not occurred until the effective dilution rate, 0.425 hr-1, and the maximum alcohol productivity was around 5.5 g/1·hr. In this case, the effective dilution rate was 0.25 hr-1 and the influent sugar concentration was distributed from 85 g/l to 135 g/1.

• KSBB Journal
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• v.21 no.5
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• pp.336-340
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• 2006

High-density perfusion cultivation was performed to produce extracellular polysaccharide(ECP) as immunostimulating agents in suspension cell cultures of Angelica gigas Nakai. In batch culture, the maximum cell density was 16.8 gDCW/L at day 6 and 0.9 g/L of ECP was obtained at day 8. When the medium exchange was started at the fifth day after inoculation for the perfusion culture, high concentration of the cells at 23.8 gDCW/L could be achieved with continuous production of ECP. Treatments of ultrasound and Pluronic F-68 were found to be helpful for the secretion of intracellular ECP into the culture medium.

• Journal of Korean Society of Forest Science
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• v.81 no.2
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• pp.183-190
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• 1992

The influence of various levels of major medium components such as sucrose, nitrate, phosphate, plant growth regulators, and light intensity for cell growth and the production of anthocyanin content in cell cultures of Populus alba ${\times}$ P. glandulosa were investigated. Best results for anthocyanin yield were obtained using Murashige and Skoog(MS) medium containing 5% sucrose, 12.5% nitrate, 200% phosphate, 1.0mg/l indole-3-acetic acid(IAA), 1.0mg/l benaylaminopurine(BAP), and continuous illumination of 7,000 lux. On the other hand, maximum cell growth was achieved with 5% sucrose, 50% nitrate above 400% phosphate compare with that of MS basal mediumi, and 0.5mg/l 2, 4-dichlorophenoxyacetic acid(2, 4-D). Anthocyanin accumulation in a suspension cultured cells of given genotype was stimulated by subculturing onto the medium lacking 2, 4-D. Pigmented cell clusters were extracted with methanol containing 1% hydrochloric acid (HCl) and then anthocyanin was identified by thin layer chromatography (TLC) and U. V. spectrophotometer.

• Korean Journal of Plant Tissue Culture
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• v.22 no.1
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• pp.41-46
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• 1995

Leaf mesophyll protoplasts of Dianthus superbus were cultured in MSP1 liquid medium supplemented with 0.5 mg/L BAP, 2.0 mg/L NAA and 9% mannitol. Protoplast-derived colonies were formed after 3 to 4 weeks of culture in the dark at 27$^{\circ}C$. These colonies were kept under continuous illumination (21.5 $\mu$E. m-2 sec-1) for 2 weeks and finally most of the colonies became green microcalli, about 3 mm in diameter. When green microcalli were transferred to MS solidified medium with 2.0 mg/L 2,4-D, they formed embryogenic calli after 4 week of culture. These calli were then transferred onto $N_{6}$ medium containing 0.1mg/L 2,4-D, 0.1 mg/L NAA, 2.0 mg/L kinetin and 2.0 g/L casein hydrolysate and cultured under illumination. After 5 weeks of culture the calli gave rise to multiple shoots of 10 to 15 per callus. Upon transfer onto MS medium containing 2.0 mg/L NAA, they were noted. The regenerates were successfully transplanted into potting soil.

• Microbiology and Biotechnology Letters
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• v.8 no.1
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• pp.55-60
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• 1980

Some of the cultural conditions were improved in order to obtain the higher biomass of Lactobacillus bulgaricus NLS-4 which has the higher lactic acid producing activity as well. Among eight media including 11％ non-fat milk medium as a control, the TIP medium was selected. By a batch experiment, the maximum cell concentration could be increased to 1.0$\times$10$^{9}$ cells per $m\ell$ when the organism was grown at 38$^{\circ}C$ for 18 hours with agitation speea of 200 rpm and under the constant level of pH 6.5 con-trolled with 1 N KOH solution in the selected medium. The cell concentration was further increased to 2.3$\times$10$^{9}$ cells per me in the steady state of continuous culture at the dilution rate of 0.17 hr$^{-1}$ for 18 hours.