• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.4
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• pp.560-566
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• 1998

The bacteriocin produced by Lactobacillus sp. GM7311 showed strong inhibitory activity against the growth of three Gram positive bacteria, Listeria monocytogenes, Bacillus subtilis, and Staphylococcus aureus. When the bacteriocin was added to the culture at different phases, viable cells of all of the tested strains were decreased, although the most inhibited phase was different. Thereby, when the bacteriocin $(100\;Bu/m{\ell})$ was added to exponential and stationary phase of L. monocytogenes, the rapid reduction of viable cell counts occured. And, in the case of B. subtilis, the highest inhibitory effect occured at lag phase and mid-exponential phase by the addition of the bacteriocin under same condition as mentioned above. Also, we can observe the accelerated reduction of survivors counts for the all of the phase except stationary phase in the S. auresus. Transmission electron microscopic observation of L. monocrogenes and B. subtilis treated with bacteriocin revealed apparent Iysis of the cell wall and excretion of the cell contents, indicating bacteriolysis. Also, the amino acids and fatty acids compositions were different from controls. However, the Iysis of cell wall didn't occur in S. aureus, though the cytoplasmic materials were reduced. This result indicates that the bacteriocin inhibits the synthesis of nuclear materials such as DNA, RNA and proteins.

• Korean Journal of Animal Reproduction
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• v.23 no.1
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• pp.85-92
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• 1999

This study was designed to determine effect of cryoprotectant kinds and cell stages on OPP vitrification method in mouse embryos. The freezing speed, cryoprotectants and cell stage could affect of embryo viability following various vitrification methods. The vitrification solution used were consisting of 40% (v/v) ethylene glycol, 18% (w/v) Ficoll, 0.3 M sucrose solution in holding medium (D-PBS supplemented with 5% FCS: HM) (EFS) or 16.5% ethylene glycol , 16.5% dimethyl sulfoxide, 0.5 M sucrose in HM (EDS). The embryos were collected from oviduct at 18 h after hCG injection and then washed and cultured in mHTF medium until use. In experiment 1, the blastocysts were vitrified by OPP straw to determine the optimal vitrification solution of EFS or EDS. The post-thaw survival rates at re-expanded stage rates were significantly different between EFS and EDS (95.0 vs 100%), but at hatching stage was not different between EFS and EDS (90.0 vs 95.0%). respectively. In experiment 2, zygotes, 2-, 4-cell, morula and blastocysts were vitrified by OPP method to determine the acceptable of early stage embryos. The development rates to expanded blastocyst in zygote (70.0%) were significantly lower rather than those in 2-, 4- 8-cell, compacted morula or blastocyst (89.7, 90.0, 92.8, 97.6 or 97.5%), respectively. However, the cell number of post-thaw developed to expanded blastocyst in blastocyst and control blastocyst stage (39.6$\pm$2.81, 35.7$\pm$2.98) were significanty higher than those in zygote, 2-, 4-, 8-cell, compacted morula (29.8$\pm$3.21, 31.3$\pm$3.83, 29.3$\pm$3.58, 28.9$\pm$3.21 or 30.8$\pm$2.93). In experiment 3, the zygotes were exposed in VSl for 1, 2, and 3 min to the optimal exposed time. The cleavage rates (91.6, 88.5, 88.9%) and develop mental rates to blastocyst (83.3, 74.3 and 69.4%) depends on the exposed time in VSl were not significantly different among 1, 2, or 3 min, respectively. The cell number also were not significantly different among exposed time in VS1. respectively. These results indicate that OPP method could be useful for vitrification either EFS or EDS vitrification solution. The post-thaw survival rates at zygote were significantly lower than those at 2-, 4-, 8-cell, morula or blastocyst, respectively. The zygote stage were more sensitive rather than late stage embryos. The exposing time in VS1 for 1 min was better than that for 2 or 3 min, even it was not significantly different. The OPP vitrification method could be useful of mouse embryos either with EFS or EDS vitrification solution.

• Korean Journal of Agricultural Science
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• v.8 no.2
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• pp.238-243
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• 1981

This experiment was carried out to study the availability of Korean peat as a main carrier material of rhizobial inoculant, using the alfalfa strain Rhizobium meliloti M 14 which was isolated in the previous report. Modification of powdered peat with calcium carbonate and other materials was studied; inoculation of the peat with culture broth, maturation of the mixture under different conditions, and survival of the strain in the peat culture was examined. The results obtained were as follows. 1. Peat produced in Pyongtak was highly acidic, pH 3.8, and addition of calcium carbonate by 14% was required for pH adjustment to 6.4. However the amount of calcium carbonate could be reduced by 4 to 8% when carbon or charcoal was mixed with the peat. 2. Viable number of the strain reached to $7-9{\times}10^9cells/g$ after 3 days, when inoculated with the culture broth of early stationary growth phase and matured in unsteriled peat of open trays; and the number in steriled peat was $1.1-6.2{\times}10^{10}cells/g$ after 5 days, when matured in closed bottles. 3. Survival of the strain was affected markedly by storage temperature, and positive effect of D-sorbitol on the viability was recognized at elevated temperatures, when added as an additional carbon source and moistening agent. Glycerol, sorbitol, or sodium lactate was utilized by the strain as a sole source of carbon, and the decimal reduction time of viable number in the peat culture was was found to be 8 to 9 weeks at $25^{\circ}C$ when these agents were added by 0.5%.

• Journal of Applied Biological Chemistry
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• v.54 no.1
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• pp.7-14
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• 2011

Bacillus subtilis JK-1 showed degradation activity against crude oil, gasoline, kerosene, and light oil, and this strain was used as a crude biosurfactant producing microorganism in this study. To optimize the culture medium for production of crude biosurfactant, the influences of various carbon, nitrogen and mineral sources were assessed. The highest biosurfactant production by B. subtilis JK-1 was observed after 96 h cultivation, containing 1.0% (w/v) soluble starch as a carbon source and 0.5% (w/v) skim milk as a nitrogen source, and carbon to nitrogen concentraion (C/N) ratio was 2.0. For the biosurfactant production 0.1% (w/v) of $KNO_3$ was the most effective mineral source. Comparison of biosurfactant production indicates that B. subtilis JK-1 produces more biosurfactant in the optimum medium established in this study than LB and TSB. Under the optimum medium, the surface tension of culture broth of B. subtilis JK-1 was decreased from 47.3 dyne/cm to 24.0 dyne/cm after cultivation of 48 h.

• Microbiology and Biotechnology Letters
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• v.20 no.5
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• pp.527-533
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• 1992

The optimal conditions for cellulase and xylanase production by Trichoderma reesei 28217 were studied for enzymatic deinking of old newspaper. The amounts of cellulase and xylanase from the strain was varied by initial medium pH, Tween 80, inoculum size of spore suspension, and carbon and nitrogen sources. The optimal conditions for cellulase production were pH 5.0-6.5, 0.02% of Tween 80, 0.5-1.0% of inoculum size of spore suspension ($1{\times}10^{7}$/ml). cottonseed meal as nitrogen source, and corn flour as carbon source. On the other hand, the optimal conditions for xylanase production were pH 6.5, 0.01% of Tween 80, corn steep liquor as nitrogen source, and disintegrated old newspaper as carbon source. The inoculum size for xylanase production was the same as for cellulase production. The concomitant production of cellulase and xylanase in shake flask culture was efficiently induced in the medium containing 0.5% cottonseed meal as nitrogen source and 1.0% old newspaper and 2.0% corn flour as carbon sources. In this case the activities of cellulase and xylanase produced were 6.11-7.22 IU/mJ and 97.7 IU/ml. respectively. However, the cellulase production in $5{\ell}$ fermentor scale was slightly decreased compared with that in flask scale. Moreover, xylanase production was severely reduced in a fermentor scale. The study for the reason of decreased enzyme production in fermentor is further needed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.11
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• pp.1612-1617
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• 2009

Aspergillus sp. 101 was isolated from the Korean traditional soybean paste for the production of a salt-tolerant protease. The optimal condition for the production of a salt-tolerant protease was determined with various energy sources such as carbon, nitrogen, and protein, and at different culture conditions such as temperature, pH, incubation time and NaCl concentration. The most favorable organic nitrogen sources were 2% defatted soybean flour (DSF) and soy protein isolate (SPI). Optimal pH and temperature were pH 6.0 and $25{\sim}27^{\circ}C$, respectively. Therefore, Aspergillus sp. 101 protease was a mild acid (or neutral) protease. Protease production was the highest at 0.1% concentration of $CaCO_3,\;K_2HPO_4$ and Arabicgum. Aspergillus sp. 101 could grow in culture medium at 15% NaCl concentration and produce a salt-tolerant protease even at 7% NaCl. The cell mass and protease activity of Aspergillus sp. 101 cultured in a modified medium was comparatively higher in Czapek dox and protease producing media. Hence, Aspergillus sp. 101 protease can be utilized in soy or fish sauce industry as a salt-tolerant protease starter.

• Applied Biological Chemistry
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• v.23 no.4
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• pp.228-241
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• 1980

The red ginseng extract and its components were investigated for their activation effects on the growth of Saccharomyces cerevisiae IAM and Saccharomyces formosensis No. 396 IAM. Changes in the number of cells, alcohol production, $CO_2$ evolution, pH and the rate of sugar consumption and of fermentation were compared during growth at $30^{\circ}C$ for 120 hours. The addition of ethanol extract and saponins from red ginseng were found to exihibite a significant increase in all physiological activaties of yeast, and its maximum activites were obtained at 1.5% ethanol extract concentration. The physiological effects of panaxadiol and panaxatriol, two major groups of saponin, were also compared to those of crude saponin and found that the former showed a small increase in physiological changes. However the difference was not significant. The overall contents of ginsenosides of ethanol extract and crude saponin during fermentation were not significantly affected by the growth of roasts, except a small increase in ginsenoside $-Rg_2$ and decrease in -Rd.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.424-431
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• 2017

This study was conducted to set the optimum nutrient solution concentration by growth stage for new strawberry cultivars 'Berrystar' and 'Jukhyang'(Fragaria ${\times}$ ananassa Duch. cvs. 'Berrystar', 'Jukhyang') grown through hydroponics to improve the quality and yield. Three different EC levels were applied to the nutrient solution. The treatment levels were 0.7, 1.0 and 1.3 times higher than the nutrient concentration standard for 'Seolhyang' based on the 'Manual for strawberry cultivation' of Rural Development Administration. Based on the results, there were no significant differences in growth of 'Berrystar' by EC level. 'Jukhyang' showed the most vigorous growth grown in 1.3 times higher nutrient concentration. While the growth of 'Berrystar' and 'Jukhyang' grown in higher EC level has leaves with more chlorophyll concentration. However the quantum yield of leaves was not affected by the treatments. On the treatment with 1.3 times higher EC level, the weight, length, width and firmness of 'Berrystar' and 'Jukhyang' were significantly high. The sugar contents of the harvest analyzed by HPLC did not differed particularly, but the percentage composition of reducing sugar and non-reducing sugar were presented differently depending on the treatments. Marketable fruit yield increased as nutrient concentration increases. However, there were no large differences by treatments. Meanwhile, 'Jukhyang' showed significant difference by nutrient concentration and had the largest yield for a treatment grown in 1.3 times higher EC level. Based on these results, it is recommended to provide the same nutrient solution concentration level to the nutrient concentration standard of 'Seolhyang' for 'Berrystar', and the 1.3 times higher level for 'Jukhyang'.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.12
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• pp.1835-1842
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• 2014

Various microorganisms are involved in the fermentation of Mageoli, Korean traditional liquor. Among them, the most predominant microorganism is yeast, including Saccharomyces cerevisae. This study investigated the effects of crude polysaccharides separated from Mageoli mash (CP-M) on activation of peritoneal macrophages in cell culture medium. Four types of yeasts, S. cerevisae 89-1-1, 98-2, 268-3, and 113-4, were used. When peritoneal macrophages were treated with $10{\mu}g/mL$ of CP-M fermented with S. cerevisae 113-4, the concentration of nitric oxide (NO) in the medium was highest ($33.3{\mu}M$). The concentrations of IL-6 and -12 were also highest at 116.3 pg/mL and 59.8 pg/mL, respectively. In the case of CP-M cultured at 15, 20, and $30^{\circ}C$ after inoculation with S. cerevisae 113-4 and fermented at different temperatures, production of NO and IL-6 by peritoneal macrophages did not change compared to the control. For CP-M obtained after fermentation at $25^{\circ}C$, however, NO concentration increased 2.7~3.3 fold and IL-6 concentration by 5.7 fold compared to the control. Furthermore, the effect of fermentation period on expression of CP-M functionality was examined. NO production by CP-M of the 5th day mash was highest, increasing 2.2 fold compared to 0-day CP-M. However, there were no significant differences in concentration of IL-6 or -12 according to different fermentation periods, although CP-M showed a large decrease after 10 days. The results show that fermentation conditions with the highest activity were observed in CP-M inoculated with S. cerevisae 113-4 and fermented at $25^{\circ}C$ for 5 days. CP-M consisted of 78.6% neutral sugar, 11.6% acidic polysaccharide, and 9.8% protein. In particular, the sugar composition of neutral sugar consisted of mannose (47.8%), glucose (29.6%), and galactose (12.7%). Based on the results, CP-M is assumed to be an extracellular polysaccharide originating in yeast with high mannose content.

• Korean Journal of Food Science and Technology
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• v.12 no.2
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• pp.97-102
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• 1980

Cladosporium fulvum, Aspergillus ochraceus, Aspergillus terreus and N-1 (unidentified species) were cultured on the artificial media containing sucrose as a carbon source at 20, 25 and $30^{\circ}C$ for 10 to 12 days. The lipids in the felts were extracted with chloroform-methanol mixture and the class composition and fatty acids of the lipid were determined. The summarized results are as follows 1. The average felts produced by each species per 100 ml of media were $3.82{\pm}0.30g$ for Cl. fulvum, $2.62{\pm}0.23g$ for Asp. ochraceus, $4.24{\pm}0.25g$ for Asp. terreus and $4.62{\pm}0.10g$ for N-1. Their crude fat contents $27.5{\pm}1.61%,\;50.47{\pm}1.00%,\;46.6{\pm}1.59%$ and 33.78 % and the fat coefficient 6.92, 8.88, 13.01 and 10.28, respectively. 2. The lipids produced by these species were mainly composed of triglyceride and the next free fatty acid in Cl. fulvum and N-1 and phospholipid Asp. ochraceus and Asp. terreus. 3. The major fatty acids of the lipids were in order of oleic, palmitic, linoleic and stearic acids in Asp. ochraceus, Asp. terreus and Cl. fulvum and linoleic, palmitic, oleic and stearic acid in N-1. The total percentage contents of these major fatty acids were over 98 % the former and over 95 % the latter. 4. The constituent fatty acids of the lipid were changed depending on the incubation temperature but hardly found a certain tendency except linoleic acid which was higher at lower temperature. 5. The total percentages of unsaturated fatty acids in the lipids were $50{\sim}60%$ and comparatively higher at lower incubation temperature.