• The Korea Journal of Herbology
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• v.26 no.1
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• pp.53-58
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• 2011

Objectives : The purpose of this study is to investigate effects of Scutellariae Radix Water Extract on hydrogen peroxide production in RAW 264.7 mouse macrophages. Methods : Scutellariae Radix produced from South Korea (SK) and Scutellariae Radix produced from China (SC) were extracted by hot water. Effects of SK and SC on hydrogen peroxide production in RAW 264.7 were measured by dihydrorhodamine 123 assay after 2, 4, 20, 24, 28, 44, and 48 h incubation at the concentrations of 10, 25, 50, and 100 ug/mL. Results : SK significantly increase hydrogen peroxide production in RAW 264.7 cells for 2, 4, 20, 24, 28, 44, and 48 h incubation at the concentrations of 10, 25, 50, and 100 ug/mL (P < 0.05). SC also significantly increase hydrogen peroxide production in RAW 264.7 cells for 4, 20, 24, 28, and 48 h incubation at the concentrations of 10, 25, 50, and 100 ug/mL (P < 0.05). For 2 h incubation, SC significantly increase hydrogen peroxide production in RAW 264.7 cells at the concentrations of 10, 25, and 100 ug/mL (P < 0.05). For 44 h incubation, SC significantly increase hydrogen peroxide production in RAW 264.7 cells at the concentrations of 10, 25, and 50 ug/mL (P < 0.05). Conclusions : These results suggest that Scutellariae Radix has the immune - enhancing property related with its increasement of hydrogen peroxide production in macrophages.

• The Korea Journal of Herbology
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• v.38 no.1
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• pp.1-9
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• 2023

Objectives : The aim of this study was to investigate the effect of baicalein (BA) on the production of hydrogen peroxide in peptidoglycan-stimulated RAW 264.7 mouse macrophages. Methods : Peptidoglycan-stimulated RAW 264.7 were incubated with baicalein at concentrations of 50 and 100 µM. Incubation time is 30 min, 2 h, 12 h, and 18 h. After incubation, The production of hydrogen peroxide in RAW 264.7 was measured with dihydrorhodamine 123 assay. Berberine and gallic acid were used as the comparative materials. Results : BA at the concentration of 50 and 100 µM did not show cytotoxicity on RAW 264.7 for 24 h incubation. For 30 min, 2 h, 12 h, and 18 h incubation, BA at the concentration of 50 and 100 µM significantly inhibited the production of hydrogen peroxide in RAW 264.7 stimulated by peptidoglycan (p<0.05). In details, production of hydrogen peroxide in peptidoglycan-stimulated RAW 264.7 treated for 30 min with BA at concentrations of 50 and 100 µM was 93.91% and 93.52% of the control group treated with peptidoglycan only, respectively; the production of hydrogen peroxide for 2 h was 93.8% and 92.71%, respectively; production of hydrogen peroxide for 12 h was 94.86% and 95.93%, respectively; production of hydrogen peroxide for 18 h was 95.37% and 96.48%, respectively. Conclusions : BA might have anti-oxidative activity related to its inhibition of hydrogen peroxide production in peptidoglycan-stimulated RAW 264.7 macrophages.

• Journal of Applied Biological Chemistry
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• v.50 no.2
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• pp.46-51
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• 2007

Lipases are industrially useful versatile enzymes that catalyze numerous different reactions. Among lipases functioning under extreme conditions, alkaline lipase is useful in detergent industry. Lipase from yeast strain Yarrowia lipolytica NRRL Y-2178 was most active under alkaline condition, and initial medium pH for most lipase production was also alkaline [Lee et al., 2007, J Microbiol Biotechnol, 17(6)]. High lipase production was achieved using Y. lipolytica NRRL Y-2178. Optimal incubation time for lipase production at $25^{\circ}C$ was 72 h. Optimal temperature, when incubated for 72 h, was $27.5^{\circ}C$. Lipase production but not cell growth was very sensitive to concentrations of glucose and glycerol as efficient carbon sources, showing optimal concentrations of 1.0 and 1.5% (w/v), respectively. Lipase production was highly stimulated by $Ca^{2+},\;K^+,\;and\;Na^+$, but was inhibited by $Co^{2+},\;Cu^{2+},\;Mn^{2+},\;Na^+,\;and\;Fe^{2+}$. Maximum lipase production at 0.1 mM $Ca^{2+}$ for 72 h incubation at $27.5^{\circ}C$ was 649 units/mL.

• Journal of Microbiology and Biotechnology
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• v.2 no.4
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• pp.284-287
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• 1992

Repeated-batch and continuous cultures of Lactococcus sp. 1112-1 were carried out for bacteriocin production using a glucose-casein medium. Repeated-batch culture did not efficiently enhanced the bacteriocin production. Continuous production was possible at the dilution rate of 0.4 $h^{-1}$. Maximum specific production rate ($Q^p$), bacteriocin production and biomass at the dilution rate were 347, 136 IU/g/h, 2, 121 IU/ml and 2.45 g/L, respectively.

• KSBB Journal
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• v.18 no.6
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• pp.473-478
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• 2003

The purpose of this study is to look for the optimal conditions of methane production. The conditions tested for methane production enhancement were temperature, pH, carbon source, nitrogen source, and inhibitor which can affects methane production. As a result, optimal conditions for methane production were 30$^{\circ}C$, neutral pH, methanol as a carbon source, NH$_4$Cl as a nitrogen source. 2-Bromoethanesulfonic acid was used as an inhibitor which can affects methane production. Existence in broth less than 10mM, inhibited methane production. Organic acid measurements revealed that formic acid exists in broth as majority.

• Korean Journal of Microbiology
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• v.17 no.1
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• pp.16-24
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• 1979

In order to investigate the production of aflatoxin in various conditions such as pH, moisture and temperature, 27 smaples were inoculated with Aspergillus flavus, and in addition 3 smaples were inoculated with the mixture of Aspergillus flavus and Bacillus subtilis and cultured under the conditions such as $20^{\circ}C$ and 30% moisture contents. The following results were obtained : 1) Aflatoxin production was the highest at pH 5.0 and relatively high at pH 7.0. Its production was decreased significantly when pH reached 9.0. 2) The yield of aflatoxin was shown comparatively high level at 30% moisture contens. The higher moisture contents was, the lower aflatoxin production was. 3) The highest level of aflatoxin production was at $20^{\circ}C$, and comparatively high level was at $30^{\circ}C$. However, its production was fairly low at $40^{\circ}C$. 4) The highest crude aflatoxin production was 5,093ppm $(B_1,\;1.912\;ppm;\;B_2,\;0.521\;ppm;\;G_1,\;2.119\;ppm;\;G_2,\;0.541\;ppm)$ at 30% moisture, pH 5.0 and $20^{\circ}C$ and the lowest one 2.197 ppm $(B_1,\;0.793\;ppm;\;B_2,\;0.185\;ppm;\;G_1,\;0.102\;ppm;\;G_2,\;0.381\;ppm)$ at 63% moisture, pH 9.0 and $40^{\circ}C$ 5) When Aspergillus flavus and Bacillus subilis were cultured together under the conditions such as $20^{\circ}C$ and 30% moisture, aflatoxin production was decreased by 27% comparing with the culture of Aspergillus flavus alone.

• Environmental Analysis Health and Toxicology
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• v.8 no.3_4
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• pp.1-5
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• 1993

Using mixed incubation of cultured endothelial cells, cultured fibroblasts, neutrophils activated with PMA and paraquat, the production of superoxide anion, $H_2O$$_2$and lipoxygenase metabolites (5-HETE and 12-HETE) of arachidonate was estimated. The results was as follows: 1. Neutrophils activated with PMA was produced superoxide anion,$H_2O_2$and lipoxygenase metabolites (5-HETE and 12-HETE) of arachidonate. 2. Fibroblasts did not alter the production of superoxide anion and $H_2O_2$ by neutrophils, it was markedly reduced by mixed incubation with endothelial cells. 3. Mixed incubation with endothelial cells significantly augmented the production of 5 or 12-HETEs, but fibroblasts did not. 4. Using mixed incubation of endothelial cells, fibroblasts, neutrophils and paraquat (50ug/m1 and 100ug/m1), the production of superoxide anion, $H_2O_2$and HETEs was significantly increased on both cells at low concentration (50ug/m1), but markedly reduced at high concentration (1001g/m1). 5. Paraquat showed concentration dependent effects on arachidonate lipoxygenase metabolism.

• Transactions of the Korean hydrogen and new energy society
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• v.26 no.3
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• pp.247-259
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• 2015

This study was performed to investigate the application of dark $H_2$ fermentation to two-stage bioprocesses for organic waste treatment and energy production. We reviewed information about the two-stage bioprocesses combining dark $H_2$ fermentation with $CH_4$ fermentation, photo $H_2$ fermentation, microbial fuel cells (MFCs), or microbial electrolysis cells (MECs) by using academic information databases and university libraries. Dark fermentative bacteria use organic waste as the sole source of electrons and energy, converting it into $H_2$. The reactions related to dark $H_2$ fermentation are rapid and do not require sunlight, making them useful for treating organic waste. However, the degradation is not complete and organic acids remain. Thus, dark $H_2$ fermentation should be combined with a post-treatment process, such as $CH_4$ fermentation, photo $H_2$ fermentation, MFCs, or MECs. So far, dark $H_2$ fermentation followed by $CH_4$ fermentation is a promising two-stage bioprocess among them. However, if the problems of manufacturing expenses, operational cost, scale-up, and practical applications will be solved, the two-stage bioprocesses combining dark $H_2$ fermentation with photo $H_2$ fermentation, MFCs, or MECs have also infinite potential in organic waste treatment and energy production. This paper demonstrated the feasibility of two-stage bioprocesses combining dark $H_2$ fermentation as a novel system for organic waste treatment and energy production.

• Animal Bioscience
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• v.35 no.10
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• pp.1616-1627
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• 2022

Objective: This work was conducted to investigate the effects of oxidative stress on meat quality, mitochondrial function, calcium metabolism and ferroptosis of broilers. Methods: In this study, a total of 144 one-day-old male Ross 308 chicks were divided into 3 groups (control group, saline group, and hydrogen peroxide [H₂O₂] group) with 6 replicates of 8 broilers each. The study lasted for 42 d. The broilers in the saline and H₂O₂ groups were intraperitoneally injected with 0.75% saline and 10.0% H₂O₂ on the 16th and 37th day of the experimental period respectively, the injection volumes were 1.0 mL/kg of broiler body weight. On the 42nd day of the experimental period, two chicks were randomly selected from each cage, a total of thirty-six chicks were stunned by electric shock and slaughtered to collect breast muscle samples. Results: The H₂O₂ exposure reduced pH value, increased drip loss and shear force of breast meat (p<0.05), impaired the ultrastructure and function of mitochondria. The H₂O₂ exposure damaged the antioxidant system in mitochondria, excessive reactive oxygen species carbonylation modified calcium channels on mitochondria, which impaired the activities of key enzymes on calcium channel, resulted in the increased calcium concentration in cytoplasm and mitochondria (p<0.05). In addition, the H₂O₂ exposure increased the iron content and lipid peroxidation (p<0.05), which induced ferroptosis. Conclusion: Oxidative stress could impair meat quality by causing mitochondrial dysfunction, resulting in calcium metabolism disorder and ferroptosis.

• The Korean Journal of Food And Nutrition
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• v.11 no.4
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• pp.381-387
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• 1998

The effects of culture conditions on the production of amylase expressed by Bacillus subtilis LKS88 with a cloned gene from Streptomyces albus KSM-35 were investigated. The production of amylase was increased significantly by using sodium citrate and rice hull as a carbon source. In addition, the use of a mixture of sodium citrate and rice hull (1:1) resulted in increase of enzyme production by 20-fold when compared to that of soluble starch. The soybean meal as the nitrogen source could be partially replaced with yeast extract without changing the enzyme production yield. The amylase production was also increased by adjusting initial pH to 6.0 or by adding 0.01% SDS. Maximum amylase production was observed in the medium containing 1.5% sodium cirtate, 1.5% rice hull, 0.7% soybean meal, 0.3% yeast extract, 0.66% K2HPO4, 0.05% MgSO4$.$7H2O, 0.008% CaCl2$.$2H2O, 0.01% SDS with initial pH of 6.0. The maximum yield of amylase reached 56.6 U/ml when B. subtilits LKS88 (pASA 240) was cultured at 37$^{\circ}C$ for 36 hr.