• Journal of Aquaculture
• /
• v.15 no.1
• /
• pp.61-68
• /
• 2002

A comparative study on the effect of rearing depths at 2 (surface) and 5 (bottom) m on growth of the scallop was undertaken in Nam-myeon coastal area during June to December, 1997. There were very little difference in the levels of temperature (12.2 ~24.5$^{\circ}C$), salinity (27.3 ~33.1$\textperthousand) and dissolved oxygen (>7.05 mg/l) at a given month. But the chlorophyll level fluctuated between 1.2 and 11.0 $\mu g/l$ at the surface but below 2 $\mu g/l$ at the bosom. Highest phytoplankton density occurred in August and Ceratium dominated it during the period from June to October. Mean growth of the bay scallop at surface and bottom for the six months rearing period was as follows; 0.19 and 0.16 mm/day for shell height, and 0.16 and 0.12 g/day for total weight. Maximum predicted values of shell height calculated by von Bertalanffy growth model were 52.62 mm for the surface and 46.73 mm for the bottom reared scallop. Survival of the scallop was higher (80 %) for the surface group than that at the bottom (60%).

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.10 no.3
• /
• pp.192-197
• /
• 2005

The effects of macronutrients $(NO_3^-,\; NH_4^+\;and\;PO_4^{3-})$ on cell growth and triterpenoids production in Centella asiatica cell suspension cultures were analyzed using the Box­Behnken response surface model experimental design. In screening and optimization experiments, $PO_4^{3-}$ as a single factor significantly influenced cell growth where increasing the phosphate level from 0.1 to 2.4 or 2.6 mM, elevated cell growth from 3.9 to $14\~16g/L$. The optimum values predicted from the response surface model are 5.05mM $NH_4^+$, 15.0mM $NO_3^-$ and 2.6mM $PO_4^{3-}$, yielding 16.0g/L cell dry weight with $99\%$ fitness to the experimental data. While the $NH_4^+-NO_3^-$ interaction influenced cell growth positively in the optimization experiment, $NH_4^+$ and $NO_3^-$ as single factors; and interactions of $NO_3^--PO_4^{3-},\;NH_4^+-PO_4^{3-}$ and $NH_4^+-NO_3^-$ were all negative in the screening experiment. Cell growth and the final pH level were positively affected by $PO_4^{3-}$, but negatively affected by $NH_4^+\;and\;NH_4^+-PO_4^{3-}$ interactions. The different effects of factors and their interactions on cell growth and final pH are influenced by a broad or narrow range of macronutrient concentrations. The productions of triterpenoids however were lower than 4mg/g cell dry weight.

• Journal of Bio-Environment Control
• /
• v.9 no.4
• /
• pp.185-192
• /
• 2000

This study was conducted to develop mathematical model of respiration rate of cucumber plant under varying environmental conditions. 8.55% of gross photosynthesis of individual cucumber plant was used as respiration. Growth respiration coefficient was estimated as 0.0935. Maintenance respiration rate was estimated as 0.00158g CH$_2$g$^{-1}$ .h$^{-1}$ at 24$^{\circ}C$ of air temperature and it increased exponentially as air temperature became higher. Respiration rate decreased poportionally as content of storage carbohydrate became lower. Ion uptake respiration rate of roots was estimated as 0.6648g C$H_2O$.(gN)$^{-1}$ .

• Journal of Life Science
• /
• v.26 no.5
• /
• pp.571-583
• /
• 2016

Biogenic amines are produced primarily by microorganisms found in fermented foods and are often implicated in poisoning incidents in humans. In this study, 620 strains of microorganisms were isolated from traditional Korean fermented food in Sunchang in order to screen for non-biogenicamine-producing microorganisms present in these foods. One strain was identified and named Bacillus subtilis SCJ1, by using 16S rRNA sequencing and biochemical characterization. We investigated the cell growth of this organism in order to understand its potential for industrial application. To this end, we optimized the culture medium constituents by using the response surface methodology. The Plackett-Burman experimental design was used for screening of the medium constituents, such as molasses, yeast extract and peptone, for improving cell growth. In order to determine the optimal concentration of each constituent, we used a central composite design. Consequently, the optimized concentrations of molasses, yeast extract and peptone were predicted to be 27.5 g/l, 7.5 g/l and 17.5 g/l, respectively. By model verification, we confirmed that a 1.49-fold increase in dry cell weight compared to the basal medium-from 1.32 g/l, to 1.9722 g/l-was achieved.

• Korean Journal of Microbiology
• /
• v.51 no.1
• /
• pp.48-60
• /
• 2015

612 strains isolated from Korean traditional fermented food in Sunchang and their investigated biochemical characterization and ability of biogenic amines non-producing. We selected the SCJ4 having various activity by measurement of extracellular enzyme, antioxidant and antimicrobial activities. Selected strain SCJ4 by 16S rRNA sequencing and biochemical characterization was named Bacillus subtilis SCJ4. And then, we investigated cell growth of SCJ4, and optimized of culture medium constituents using response surface methodology as statistically method. Response surface methodology used Plackett-Burman experimental design for screening of medium constituent. Tryptone, peptone and $MgSO_4$ as medium constituent improving cell growth selected. In order to find out optimal concentration on each constituent, we carried out central composite design. Consequently, optimized concentrations of tryptone, peptone and $MgSO_4$ were predicted to be 15.35 g/L, 12.235 g/L, and 3.5 g/L respectively. Through the model verification, we confirmed about 1.28-fold improvement of the dried cell weight from 0.8767 g/L to 1.1222 g/L when compared to basal medium.

• The Korean Journal of Malacology
• /
• v.19 no.2
• /
• pp.143-152
• /
• 2003

Water temperature during the culturing period was 10.4-25.5$^{\circ}C$ and there was a little difference between rearing sites. Salinity (25.00-31.17 psu) and DO (over 6.13 mg/l) showed reasonable condition for the growth of bay scallop. Concentrations of chlorophyll-a were ranged 1.69-7.40 $^{\mu}$g/l, and they fluctuated monthly in the every sampling site. During the growing period from June to October, dominant phytoplankton species were Ceratium sp. in Nammeon and Hoejin, Chaetoceros sp. in Dolsan. Density of phytoplankton was high in July, August and October, but it was low in September and November. When young bay scallops were cultured for 185 days in Nammyeon, Hoejin and Dolsan, shell heights were grown for 0.19 mm/day, 0.18 mm/day and 0.16 mm/day, respectively, and total weights were increased 0.16 g/day, 0.16 g/day and 0.13 g/day, respectively. Daily growth rates of shell height were 0.606%, 0.581% and 0.549%, and daily growth rates of total weight were 1.972%, 1.857% and 1.746%, respectively. Maximum predicted values of shell height calculated by von Bertalanffy growth model were 52.62 mm, 51.74 mm and 48.91 mm, respectively. Survival rate was the highest in Nammyeon (87.0%), but the rates in Hoejin and Dolsan sharply decreased after November.

• Journal of Microbiology and Biotechnology
• /
• v.9 no.6
• /
• pp.726-731
• /
• 1999

It was discovered that ammonium phosphate in the medium played an important role in both growing mycelium and producing exopolysaccharides (EPS) from G. lucidum. In lower concentration levels of ammonium phosphate (0-3 g/l), an improved mycelial growth was observed by maintaining more filamentous morphology than in high concentrations (5-11 g/l). In addition, it was confirmed by comparing the factual dimension and frequency of the area regarding the mycelial pellets. This must be attributed to limitations of nutrient transfer by maintaining filamentous mycelium during the cultivation in a low ammonium phosphate containing medium. On the other hand, the best EPS production was observed in medium with the absence or low concentration of ammonium phosphate. The shear stress of the culture broth was greatly affected by the shear rate, as compared with that of the culture broth with high ammonium phosphate concentration. The rheological characteristics of the fermentation broth and filtrate worked well according to the Herschel-Bulkley model. It was also found that the morphological changes of the mycelium resulting from the ammonium phosphate concentration directly affected the rheological characteristics of the system and resulted in reversely affecting the EPS production levels. Based on these results, it can be concluded that delicate regulation of the ammonium phosphate concentration in the culture media should be provided in order to obtain optimal mycelial growth and/or EPS production.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.40 no.1
• /
• pp.39-49
• /
• 2007

Species competition among the toxic dinoflagellates Alexandrium tamarense and Gymnodinium catenatum and the diatom Skeletonema costatum was simulated using a mathematical model. Prior to the model simulation competition experiments using the three species were conducted to obtain data for validation by the simulation model. S. costatum dominated at a density of ${\sim}10^{4}\;cells/mL$ compared to the other species in the medium with dissolved inorganic phosphorus (DIP). The growth of S. costatum was also stimulated by the addition of dissolved organic phosphorus (DOP), such as uridine-5-monophosphate (UMP) or glycerophosphate (Glycero-P), although this species is unable to take up DOP. This implies that the growth of S. costatum may be supported by DIP, which is hydrolyzed by alkaline phosphatase produced from A. tamarense and G. catenatum. The species competition model was run assuming the environmental conditions of northern Hiroshima Bay, Japan, during spring and summer. G. catenatum increased in cell density and neared the level of S. costatum at the end of the calculation. In the sensitivity analyses by means of doubling and halving parameters, depleted DIP had little effect on the cell density of G. catenatum. However the growth of A. tamarense and S. costatum was significantly affected by changes in the parameter values. These results indicate that if DIP depletion is ongoing, species that have a large phosphate pool in their cells, such as G. catenatum, will predominate in the community.

• Journal of Environmental Science International
• /
• v.12 no.3
• /
• pp.299-306
• /
• 2003

The purpose of this study is to investigate the characteristics of water quality in Jeju harbor and to estimate pollutant loadings discharged into Jeju Harbor. To know characteristics of water quality in Jeju harbor, and pollutant loadings of Sanzi river, we have investigated from August, 2000 to May, 2001. The results showed that the concentrations of COD, DIN and DIP were in the range of 1.00∼4.85 mg/L (mean 2.15 mg/L), 2.14∼74.0 $\mu\textrm{g}$-at/L(mean 12.20 $\mu\textrm{g}$-at/L) and 0.52∼4.00 $\mu\textrm{g}$-at/L(mean 1.18 $\mu\textrm{g}$-at/L), respectively. These values were under III class of seawater quality criteria. The ratio of nitrogen to phosphorus was lower than 16 except for Station 1 in Jeju harbor. Therefore, nitrogen was playing an important role in phytoplankton growth as limiting factor in Jeju harbor. The mean values of eutrophication index were exceeding 1, which was the eutrophication criteria. The results of estimating pollutant loadings at Sanzi river are 0.30 ton/day for COD, 300 kg/day for DIN and 18.0 kg/day for DIP, respectively.

• Korean Journal of Soil Science and Fertilizer
• /
• v.50 no.5
• /
• pp.422-433
• /
• 2017

Unmanned Aerial Vehicle (UAV) has several advantages over conventional remote sensing techniques. They can acquire high-resolution images quickly and repeatedly. And with a comparatively lower flight altitude, they can obtain good quality images even in cloudy weather. In this paper, we developed for estimating garlic growth at field scale model in major cultivation regions. We used the $NDVI_{UAV}$ that reflects the crop conditions, and seven meteorological elements for 3 major cultivation regions from 2015 to 2017. For this study, UAV imagery was taken at Taean, Changnyeong, and Hapcheon regions nine times from early February to late June during the garlic growing season. Four plant growth parameters, plant height (P.H.), leaf number (L.N.), plant diameter (P.D.), and fresh weight (F.W.) were measured for twenty plants per plot for each field campaign. The multiple linear regression models were suggested by using backward elimination and stepwise selection in the extraction of independent variables. As a result, model of cold type explain 82.1%, 65.9%, 64.5%, and 61.7% of the P.H., F.W., L.N., P.D. with a root mean square error (RMSE) of 7.98 cm, 5.91 g, 1.05, and 3.43 cm. Especially, model of warm type explain 92.9%, 88.6%, 62.8%, 54.6% of the P.H., P.D., L.N., F.W. with a root mean square error (RMSE) of 16.41 cm, 9.08 cm, 1.12, 19.51 g. The spatial distribution map of garlic growth was in strong agreement with the field measurements in terms of field variation and relative numerical values when $NDVI_{UAV}$ was applied to multiple linear regression models. These results will also be useful for determining the UAV multi-spectral imagery necessary to estimate growth parameters of garlic.