• Plant Resources
• /
• v.3 no.2
• /
• pp.105-109
• /
• 2000

This study was carried out to find a useful mushroom at Chungnam Agricultural Research And Extention Service. Twenty materials used were collected from domestic and exotic area. These races were compared bontanical characteristics to leading varieties by PCR-RAPD methods. Mycelial growth temperature of Chongpung and Myongwol were at 20 to 25 $^{\circ}C$ and 25 to 30 $^{\circ}C$ at PDA medium, respectively mycelial growth of these varieties were similiar at pH 6.5 to 7.5. In case of mushroom cultivation temperature ranges, Chongpung was at 5 to 26$^{\circ}C$ and Myongwol was at 7 to 28$^{\circ}C$, but the optimum temperature range of these were appeared at 15 to 19$^{\circ}C$. Culture temperature of these was 23$^{\circ}C$ and period of mycelial culture was needed 23 to 24 days under 850cc/pp, while was needed 11 to 12 days at waste cotton medium. Cap color of these at first inducing mushroom was all dark blue, but at late growing stages Chongpung was shown as grey, and Myongwol was shown as dark grey. Yield of Chongpung was appeared as 46kg/3.3$m^2$ and that of Myongwol was 41kg /3.3$m^2$, while Chunchu No2 as check was 40kg/3.3$m^2$. Results from PDA medium and PCR-RAPD analysis two of these were different from others.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2006.06b
• /
• pp.235-239
• /
• 2006

The keel attached on bottom of hull part prevents yacht from flowing sideway by sailing posture. So this study has compared with characteristics of resistance depending on the shape af the lower part of fin keel in the same surface af water submersion, we have attached three different types of models of lower part of fin keels to the model ships using circulating water channel and analyzed resistance characteristics per shape to arrive at the optimum shape of reduction of resistance.

• KSBB Journal
• /
• v.6 no.2
• /
• pp.143-146
• /
• 1991

The liquifying $\alpha-amylase$ production from B. subtilis, A. oryzae and B. natto using wheat and rice bran as low cost culture medium was investigated. Among 3 strains, B. natto showed heights productivity of $\alpha-amylase$ in the outer wheat bran medium. And the optimum culture condition is pH 6.8 and $37^{\circ}C$ for the production of $\alpha-amylase$. The $\alpha-amylase$ activity of the crude enzyme and the purified enzyme are 256 unit/ml and 10,700 unit/ml, respectivitly. The $\alpha-amylase$ from B. natto cultrtured in outer wheat bran medium was purified into nearly a pure state(98.7%). And the molecular weight of the purified $\alpha-amylase$ was 34,000.

• Korean Journal of Breeding Science
• /
• v.41 no.1
• /
• pp.61-67
• /
• 2009

"Early Valley", is an early maturing potato cultivar with high yield potential. "Early Valley" is a clonal selection resulting from the cross between 'Suncrisp' and 'A87109-10'. It has medium plant height and light green foliage. "Early Valley" has medium flowering habit and white flowers. Tubers are smooth, yellow skin, light yellow flesh, round tuber shape, medium eye depth, and medium dormancy and good keeping quality. It has stable yield under wide range of climatic conditions. "Early Valley" is resistance to late blight, but moderately susceptible to common scab and hollow heart. This cultivar is also resistant to potato rotting at harvesting during the raining season. "Early Valley" has high level of antioxidant activity (about three times higher) and vitamin C (higher by 40%) than the 'Superior'. This cultivar has high level of tuber uniformity and capable of yielding 36.56 t/ha which is 17.07% higher than the control potato cultivar 'Superior' under optimum agronomical practices.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2003.10a
• /
• pp.59-67
• /
• 2003

An efficient plant regeneration system was developed for Hordeum vulgare L. cv Baegdong - an important Korean cultivar. The protocol was based on a series of experiments involving the sizes of mature embryos and the culture media. The embryo size is found to be critical for the establishment of embryogenic callus. Embryos of 1.1-1.5 mm size showed a much higher ability to produce embryogenic callus capable of regenerating green plants. The auxins picloram and dicamba proved effective in inducing callus from mature embryos. $2.5\;m;I^{-1}$ dicamba and $4.0\;mg\;I^{-1}$ picloram in Murashige and Skoog's (MS) medium was optimum for the induction of primary callus. The induced primary callus was loose and friable which ultimately developed into creamy white and compact callus after transferring into the fresh medium. Multiple shoots were induced in the MS medium supplemented with $6.0\;g\;I^{-1}$ maltose, $20\;mg\;I^{-1}$ sorbitol, $0.5\;mg\;I^{-1}$ 2, 4-D and $1.0\;mg\;I^{-1}$ kinetin and the rate was 6.5 shoots per embryo. Regenerated plants were hardy and developed roots rapidly in the medium containing $0.2\;I^{-1}$ IBA. This efficient plant regeneration system provides a foundation for generating transgenic plants of this important barley cultivar.

• Journal of Microbiology and Biotechnology
• /
• v.31 no.10
• /
• pp.1430-1437
• /
• 2021

Cronobacter sakazakii is an opportunistic pathogenic bacterium found in powdered infant formula and is fatal to neonates. Antibiotic resistance has emerged owing to overuse of antibiotics. Therefore, demand for high-yield bacteriophages as an alternative to antibiotics has increased. Accordingly, we developed a modified mass-production method for bacteriophages by introducing a two-stage self-cycling (TSSC) process, which yielded high-concentration bacteriophage solutions by replenishing the nutritional medium at the beginning of each process, without additional challenge. pH of the culture medium was monitored in real-time during C. sakazakii growth and bacteriophage CS01 propagation, and the changes in various parameters were assessed. The pH of the culture medium dropped to 5.8 when the host bacteria reached the early log phase (OD₅₄₀ = 0.3). After challenge, it decreased to 4.65 and then recovered to 4.94; therefore, we set the optimum pH to challenge the phage at 5.8 and that to harvest the phage at 4.94. We then compared phage production during the TSSC process in jar-type bioreactors and the batch culture process in shaker flasks. In the same volume of LB medium, the concentration of the phage titer solution obtained with the TSSC process was 24 times higher than that obtained with the batch culture process. Moreover, we stably obtained high concentrations of bacteriophage solutions for three cycles with the TSSC process. Overall, this modified TSSC process could simplify large-scale production of bacteriophage CS01 and reduce the unit cost of phage titer solution. These results could contribute to curing infants infected with antibiotic-resistant C. sakazakii.

• Journal of the Korean Society of Radiology
• /
• v.9 no.1
• /
• pp.9-16
• /
• 2015

The purpose of this study is finding optimum contrast medium quantity during abdominal CT using dual energy technique. The study subjects are 30 patients who had received general single energy abdominal CT and received double energy technique follow-up abdominal CT. dual energy technique abdominal CT images were obtained after setting contrast medium quantities at 30%, 40%, 50%, 60% and 70% of contrast medium quantity at the time of single energy technique. Then the contrast enhancement (Hounsfield Unit; HU) was estimated by setting-up the regions of interest at aorta, inferior vena cava, hepatic portal vein and hepatic parenchymal. The obtained values were compared to the values of the same parts measured during single energy technique abdominal CT. The results of the study were as following. The 60% set up group had HU in aorta : $210.80{\pm}13.609$, IVC : $190.40{\pm}25.215$, hepatic portal vein : $198.40{\pm}21.232$ and hepatic parenchymal : $119.20{\pm}7.98$, The single energy abdomianl CT images had HU in aorta : $205.40{\pm}16.426$, IVC : $188.20{\pm}21.476$, hepatic portal vein : $195.40{\pm}22.744$ and hepatic parenchymal : $121.00{\pm}6.595$. Therefore, it is possible to obtain contrast enhancement by dual energy technique abdominal CT similar to the same by single energy technique abdominal CT by setting-up the quantity of contrast medium at 60% of contrast medium at the time of single energy technique abdominal CT. Based on the result of this study, it is possible to decrease existing quantity of contrast medium by _% and the injection velocity can be also decreased. Accordingly, it is believed that the result of study would be quite useful for patients who have renal function disorder, weak vein or side effect of contrast medium in the past.

• KSBB Journal
• /
• v.25 no.2
• /
• pp.142-154
• /
• 2010

The protein-bound innerpolysaccharides (IPS) produced by suspended mycelial cultures of Inonotus obliquus have promising potentials as an effective antidiabetic as well as an immunostimulating agents. To enhance IPS production, intensive strain improvement process should be carried out using large amount of UV-mutated protoplasts. During the whole strain-screening process, the stage of solid growth-culture was found to be the most time-requiring step, thus preventing rapid screening of high-yielding producers. In order to reduce the cell growth period in the solid growth-stage, therefore, solid growth-medium was optimized using the statistical methods such as (i) Plackett-Burman and fractional factorial designs (FFD) for selecting positive medium components, and (ii) steepest ascent (SAM) and response surface (RSM) methods for determining optimum concentrations of the selected components. By adopting the medium composition recommended by the SAM experiment, significantly higher growth rate was obtained in the solid growth-cultures, as represented by about 41% larger diameter of the cell growth circle and higher mycelial density. Sequential optimization process performed using the RSM experiments finally recommended the medium composition as follows: glucose 25.61g/L, brown rice 12.53 g/L, soytone peptone 12.53 g/L, $MgSO_4$ 5.53 g/L, and agar 20 g/L. It should be noted that this composition was almost similar to the medium combinations determined by the SAM experiment, demonstrating that the SAM was very helpful in finding out the final optimum concentrations. Through the use of this optimized medium, the period for the solid growth-culture could be successfully reduced to about 8 days from the previous 15~20 days, thus enabling large and mass screening of high producers in a relatively short period.

• Horticultural Science & Technology
• /
• v.33 no.4
• /
• pp.518-524
• /
• 2015

The objective of this research was to investigate the influence of various depths of expanded rice hull (ERH) medium and fixation dates of runner plantlets of 'Seolhyang' strawberry on the growths in nursery field and in plastic house soil after transplanting. The five treatments in medium depths (30, 50, 70, 90, and 110 mm) and four treatments in fixation dates (1st and 15th July and 1st and 15th August) were tested. The growths of runner plantlets were investigated before transplanting to plastic house soil. The early growth and inflorescence rates of crops after transplant to plastic house soil were also investigated. The plant height and fresh weight of runner plantlets were the highest in the medium depths of 50, 70, and 90 mm. The medium depth of 30 mm had higher numbers of first roots, but lower root fresh weight compared to those of 70, 90, and 110 mm. The treatment of 30 mm in medium depth showed poorer growth in all indexes except root length and root weight compared to those of 70, 90, and 110 mm. The runner plantlets fixed on July 1 and July 15 showed good root growth and the weights of ERH adhered to form root balls were 18.3 g and 13.9 g, respectively. The detached amount of ERH was less than 40% in the two treatments when root balls were shaken by a vibratory sieve shaker. The plant growth at 45 days after transplanting to plastic house soil were not significantly different when the runner plantlets were fixed in the period from July 1 to Aug. 1. The inflorescence rates of the first cluster were 93 to 100% when runner plantlets were fixed in the period from July 1 to Aug. 1. By contrast the runner plantlets fixed on the Aug. 15 had a 67% in florescence rate for the first cluster. These results indicate that optimum depth of ERH medium was 7 cm and the ranges of optimum fixation dates are from July 20 to 25.

• Korean Journal of Medicinal Crop Science
• /
• v.2 no.1
• /
• pp.60-66
• /
• 1994

This study was conducted to determine the optimum conditions of inducing callus, proliferating callus, forming somatic embryos, and regenerating plantlets via somatic embryogenesis, for the purpose of producing artificial seeds and substantially developing plant factory technologies that can be employed to all seasons production of Bupleurum plants. Callus was efficiently induced from leaf tissues at three leaf stage in the MS medium supplemented with 2, 4-D 2mg /1 and thidiazuron(TDZ) 0.lmg /1. Callus induction from leaf tissues at maturity was mostly effective in the mixture of 2,4- D 2mg /1 and TDZ 1.0mg /1 while that from flower bud tissues was fairly good in the MS medium containing 2,4-D 1 or 2mg /1.Callus was formed in 15 to 20 days after culture initiation in the MS media supplemented with 2, 4- D 1-2mg /1 and TDZ 0.l-1.0mg /1. Such hormones as kinetin 3mg /1, GA 1mg /1, and the mixture of GA 1mg /1 and TDZ 1mg /1 effected markedly to proliferate the callus cells.The optimum temperature and light intensity for callus culture were found to be $25^{\circ}C$ and 3000 Lux, respectively. Direct plant regeneration from cultured callus was fairly made on hormone-free MS or half-strength MS medium. Somatic embryogenesis was most frequently observed in hormone-free media:60 somatic embryos per 20ml in MS medium and 28 somatic embryos per 20ml in half -strength MS medium. There were three stages-globular, heart, and torpedo-in development of somatic embryos, among which globular stage was more frequently observed in MS medium rather than in half-strength MS medium. Somatic embryos induced from suspension culture fairly differentiated a number of shoots and roots on hormone-free and half-strength MS solid medium.