• Journal of Bio-Environment Control
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• v.14 no.4
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• pp.298-301
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• 2005

Potato (Solamum tuberosum 'Dejima') plantlets were investigated on culture type and initial quantity of inoculation in bioreactor and survival rate by hydroponics for mass production. rode stems (1 to 1.5cm in length) of potato plantlets multiplied in vitro were grown for 3 weeks in liquid Murashige and Skoog (MS) medium with sucrose $30 g\; L^{-1}$. When plantlets (80-node inoculation) were raised in 10L balloon type bubble (BB) bioreactor, the healthiest growth of plantlets was obtained from explants cultured in ebb & flow culture with medium supplied periodically 12 times per day. The suitable inoculation quantity of 20L BB bioreactor was 120 pieces of stem segments (mean 2.2g fresh weight) in ebb & flow culture. Number of nodal shoot was eight on the average. In controlled culture room, survival rate of plantlets at 7 days after stem cutting was above $70\%$ when they were acclimatized by hydroponics grown in deep flow and solid medium culture. The highest survival rate of the stem cutting plantlets was in nutrient solution adjusted to EC $1.4dS{\cdot}m^{-1}$. Stem cutting plantlets through one culture could be obtained $670\~900$, when plantlets were grown in ebb & flow culture during 3 weeks using a 20L bioreactor with initial 120 pieces of nodal segments. 11 is possible In do mass production of seedlings cultured in bioreactor and hydroponics.

• Research in Plant Disease
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• v.8 no.4
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• pp.234-238
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• 2002

In vitro and in vivo activities of a biocontrol agent, Bacillus stearothermophilus strain YC4194 was evaluated for the control of Pythium damping-off of cucumber. B. stearothermophilus YC4194 inhibited germination of cystospores and formation of zoosporangia of Pythium aphanidermatum in vitro. Incorporation of a bentonite and talc based formulation(10$^{9}$ cfu/g) of B. stearothermophilus YC4194 to the nursery soils (10 g/ι soil) resulted In a significant (p=0.01) reduction in the disease severity of cucumber damping-off after inoculation with P. aphanidermatum. The control efficacy of B. stearothermophilus YC4194 formulation was not different from that of the fungicides, dimethomorph, metalaxyl, ethaboxam. When the cucumber plants were transplanted to the soil inoculated with P. aphanidermatum zoospores, the B. stearothermophilus YC4194 maintained the high population density in rhizosphere soil upto 10$^{7}$ cfu/g until 15 days after treatment.

• Journal of Mushroom
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• v.16 no.2
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• pp.61-64
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• 2018

This study was carried out to investigate the management characteristics and growth performance of L. edodes from the cooling stage to incubation. Bags of different heights and weights are available for bagging. When the medium size of $17{\times}13cm$ was used and the size of the inoculation hole was changed from 1/3 to 2/3, the browning period was shortened to 30 days. Mycelial growth was evaluated according to the cooling temperature after sterilization. It was observed to be the highest at 122 mm/15 days at $10^{\circ}C$ and 114 mm/15 days and 117 mm/15 days at $15^{\circ}C$ and $20^{\circ}C$, respectively. The contamination rate of the sawdust media before inoculation was measured as 0, $4.5{\times}10$, $1.3{\times}10^2$, $4.0{\times}10^3cfu$ at $5^{\circ}C$, $10^{\circ}C$, $15^{\circ}C$, and $24^{\circ}C$ respectively. The average of $1.6{\times}10^8$ colony forming units (cfu) of microorganisms was observed in the sawdust that had been piled for six months outdoors. In summer, the sawdust has to be used immediately after mixing. The sterilized medium had an average of $4{\times}10^3cfu$ of microorganisms at $24^{\circ}C$ and $1.3{\times}10^2cfu$ at $15^{\circ}C$. After 15 days of inoculation in vitro, the growth conditions of the sawdust was the best at 132 mm, followed by grain and liquid. When inoculated with liquid spawn, the moisture content of the substrate should be adjusted between 50% and 55% in advance.

• Journal of Plant Biology
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• v.5 no.3
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• pp.30-36
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• 1962

The mechanism of synthesis of the toacco mosaic virus(TMV) and the potato virus X(PVX) was investigated using the methods of ultraviolet light irradiation and serological analysis. In vitro irradiation of UV on the infected tobacco juice for 10 minutes caused the infectivity of TMV and PVX to decrease markedly on their respective local lesion indicator hosts, Nicotiana glutinosa L. and Gomphrena globosa L., indicating that UV destroys directly the infectivity of the virus particles. Ten minutes after the UV was irradiated on the leaves of the two indicator hosts before inoculation, the infectivity of TMV decreased as it was irradiated in vitro, whereas that of PVX increased by 26% as compared with the unirradiated control. When the two viruses were mix-inoculated in the common host of tobacco and the synthetic products were analyzed by serological methods for a two week infection period, it was found that both viruses were multiplying more rapidly and abundantly than they were singly inoculated into the same host species. Titers from mixed series were often two times as high as those of singly inoculated series. A mechanism of competition in the synthesis between the mixed viruses in the common host is postulated.

• Journal of Microbiology and Biotechnology
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• v.25 no.10
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• pp.1728-1733
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• 2015

This study was done to establish a mouse model for catheter-related biofilm infection suitable to bioluminescence imaging (BLI). Biofilm formation of Pseudomonas aeruginosa (P. aeruginosa) Xen5 grown on catheter disks in vitro and in an implanted mouse model was real-time monitored during a 7-day study period using BLI. The numbers of integrated brightness (IB) and viable bacterial count (VBC) in the biofilm disks in vitro were highest at 24 h after inoculation; the IB of biofilm in vivo was increased until 24 h after implantation. A statistical correlation was observed between IB and VBC in vitro by linear regression analysis. The actual VBC value in vivo can be estimated accurately by IB without sacrifice. In addition, we monitored the change in white blood cells (WBCs) during infection. The number of WBCs on day 7 was significantly higher in the infection group than in the control group. This study indicates that BLI is a simple, fast, and sensitive method to measure catheter biofilm infection in mice.

• The Korean Journal of Physiology
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• v.3 no.2
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• pp.17-23
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• 1969

Oxygen consumption rate $(QO_2)$ and protein content of liver and kidney of the Ehrlich ascites tumor-bearing mouse were measured from 6th till 14th day after the inoculation of $4{\times}10^6$ Ehrlich ascites tumor cells. The results thus obtained were compared with those of the groups in which; 1) Whole body x-irradiation with 400 r was done to mouse prior to the inoculation of $4{\times}10^6$ Ehrlich ascites tumor cells, 2) Same number of the irradiated tumor cells were inoculated after subjecting the tumor cells to x-irradiation with 400 r or 900 r in vitro, and 3) the normal, and the following results were obtained; 1. $QO_2$ of the liver and kidney of the tumor-bearing mouse were all lower than the normal and a gradual decrease of $QO_2$ in both liver and kidney was noted as the ascites tumor was progressively developing. 2. In the groups where whole body x-irradiation with 400 r was done, or x-irradiation of ascites tumor cells in vitro with either 400 r or 900 r, $QO_2$ of the liver and kidney were lower than the normal, and the pattern of the decrease was similar in the case of the tumor-bearing mouse. 3. Protein contents in all the groups showed lower values than the normal, and the decrease was gradual as the ascites tumor was developing. 4. $QO_2$ and protein levels in the liver were generally lower than those in the kidney. 5. A certain cancerous metabolism was, therefore, noted in the remote organs of Ehrlich ascites tumor-bearing animal.

• Journal of Microbiology and Biotechnology
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• v.17 no.8
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• pp.1300-1307
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• 2007

This study assessed the possible role of different traits in selected plant growth-promoting rhizobacteria (PGPR) for improving wheat growth and yield under natural conditions. Rhizobacteria exhibiting 1-aminocyclopropane-1-carboxylate (ACC)-deaminase activity were isolated and screened for their growth-promoting activity in wheat under axenic conditions. Five isolates belonging to Pseudomonas and one Burkholderia caryophylli isolate that showed promising performances under axenic conditions were selected and characterized for in vitro ACC-deaminase activity, chitinase activity, auxin production, P solubilization, and root colonization. These isolates were then used as inocula for wheat cultivated under natural conditions in pot and/or field trials. Significant increases in root elongation, root weight, tillers per pot, 1,000-grain weight, and grain and straw yields were observed in response to inoculation with PGPR in the pot trials. Inoculation with these PGPR was also effective under field conditions and increased the wheat growth and yield significantly. However, the efficacy of the strains was inconsistent under the axenic, pot, and field conditions. Pseudomonas fluorescens ($ACC_{50}$), which exhibited a relatively high in vitro ACC-deaminase activity, chitinase activity, auxin production, and P solubilization and more intensive root colonization, was the most efficient isolate under the field conditions. Therefore, these results demonstrated that ACC-deaminase activity is an efficient parameter for the selection of promising PGPR under axenic conditions. However, additional traits of PGPR, including auxin production, chitinase activity, P solubilization, and root colonization, are also important for selecting PGPR as biofertilizers.

• ANNALS OF ANIMAL RESOURCE SCIENCES
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• v.30 no.3
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• pp.111-120
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• 2019

The objective of this study was to investigate the effect of different feed inoculation method on rumen fermentation in an in vitro. Three experimental treatments were used: control (CON, direct dispersion of feed (2 g) in rumen fluid), combinations of direct dispersion (1 g) and nylon bag (DNB, pore size: 50 ㎛, 1 g), and nylon bag (NB, 2 g). An in vitro fermentation experiment was carried out using strained rumen fluid for 48 h incubation time and timothy was used as a substrate. At the end of the incubation, in vitro dry matter digestibility (IVDMD), in vitro neutral detergent fiber digestibility (IVNDFD), pH, volatile fatty acids (VFA), ammonia nitrogen (NH₃-N), and microbial community were evaluated and gas production was estimated at 3, 6, 12, 24, 48 h incubation periods. Gas production was higher in CON than DNB and NB at 6 and 12 h incubation time (p<0.01). There were no differences in final gas production, pH, NH₃-N concentration, total VFA production, and VFA profiles among treatments. The IVDMD was lowest in CON (p<0.01) but the IVNDFD was not differed by feed distribution methods. There were no significant differences in general bacteria and fungi. Protozoa count was highest in NB treatment among treatments (p<0.01). The abundance of cellulolytic bacteria, Ruminococcus flavefaciens and Fibrobacter succinogenes, was highest in the CON among treatments (p<0.01).

• The Plant Pathology Journal
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• v.26 no.4
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• pp.367-371
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• 2010

In this study, we evaluated the efficacy of fluopicolide to inhibit Phytophthora capsici in vitro, and to control pepper Phytophthora blight in a greenhouse and pepper fields. Fluopicolide was tested on various developmental stages of P. capsici 06-143 (a sensitive isolate to metalaxyl) and JHAW1-2 (a resistant isolate to metalaxyl). Mycelial growth and zoosporangium germination of both isolates were completely inhibited at $4.0\;{\mu}g/ml$ of the fungicide in vitro. The $EC_{50}$ (effective concentrations reducing 50%) of P. capsici 06-143 against zoospore were $0.219\;{\mu}g/ml$, while those of JHAW1-2 were $3.829\;{\mu}g/ml$. When fluopicolide was applied at 100 and $1,000\;{\mu}g/ml$ 7 days before inoculation with P. capsici 06-143 in the greenhouse test, the disease was controlled completely until 6 days after inoculation. However, the curative effect of fluopicolide was not as much as the protective effect. When fluopicolide was applied by both soil drenching and foliar spraying, the treatments strongly protected pepper against the Phytophthora blight disease. Based on these results, fluopicolide can be a promising candidate for a fungicide to control P. capsici in the pepper fields.

• Korean Journal of Plant Resources
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• v.24 no.2
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• pp.208-213
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• 2011

This study was carried out to determine the effect of medium solidity, salt strength, sugar and nitrogen sources, and pH levels on in vitro multiplication of pathogen-free yam (Dioscorea opposita Thunb.). Liquid medium was more effective in the growth of plant height, fresh weight, and formation of microbulb than the solid medium. Optimal condition for plant fresh weight, growth, and multiplication axillary bud was in 1MS salt strength with 60 $g{\cdot}L^{-1}$ sucrose and half strength of $KNO_3$. Optimal condition for microbulb formation was $\frac{1}{2}$ MS salt strength supplemented with glucose 60 $g{\cdot}L^{-1}$ and half strength of $KNO_3$. The number of leaves and nodes were sharply increased from 2 to 5 weeks, whereas plant fresh weight was steadily increased from 3 to 11 weeks after inoculation. Microbulbs were formed at 2 weeks after inoculation and continuously increased until 12 weeks.