• Journal of the Korean Wood Science and Technology
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• v.38 no.6
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• pp.561-567
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• 2010

In this study, we evaluated optimal conditions for ethanol production of the spruce hydrolysate (SH) obtained from diethyl oxalate pretreatment. Fermentable sugar concentration in SH was 29.04 g/${\ell}$ except arabinose. Monosaccharides obtained from the oligomer degradation were mainly mannose (39.26 g/${\ell}$) and galactose (12.83 g/${\ell}$). Concentration of 5-HMF and furfural which are inhibitors on ethanol fermentation were 0.09 g/${\ell}$ and 0.04 g/${\ell}$ respectively. Concentration of acetic acid and total phenolic compounds in SH were 1.4 g/${\ell}$ and 2.83 g/${\ell}$. Ethanol production using hydrolysate was 11.7 g/${\ell}$ at optimal pH 6.0 after 48 h. Specific ethanol production was 0.15 (g/(${\ell}^*h$)) at pH 5.0 and 5.5. while that was 0.24 (g/(${\ell}^*h$)) at pH 6.0. Specific ethanol production has difference depend on initial pH for fermentation. Ethanol production was 14.3 g/${\ell}$ after 48 h when xylanase 20 IU was added in SH for degradation of oligomer during fermentation. It implied that ethanol production increased by 22.2% compare with control (without xylanase).

• Journal of Hydrogen and New Energy
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• v.25 no.4
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• pp.337-343
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• 2014

This study was conducted to evaluate the characteristics of dark fermentative $H_2$ production from microalgae (Chlorella vulgaris) using batch reactors under mesophilic (25, $35^{\circ}C$) and thermophilic (45, $55^{\circ}C$) conditions. The $H_2$ yield and $H_2$ production rate increased with increasing temperature. The maximum $H_2$ yield and $H_2$ production rate were 56.77 mL $H_2/g$ dcw, 3.33 mL $H_2/g\;dcw{\cdot}h$ at $55^{\circ}C$, respectively. The activation energy calculated using Arrhenius equation was 36.24 kcal/mol, which was higher than that of dark $H_2$ fermentation of glucose by anaerobic mixed culture. Although the concentration of butyrate was maintained, the concentrations of lactate and acetate increased with increasing temperature. The $H_2$ yield was linearly proportional to acetate/ butyrate ratio.

• Journal of Microbiology and Biotechnology
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• v.26 no.3
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• pp.558-566
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• 2016

Biotic agents such as fumarate-reducing bacteria can be used for controlling methane (CH₄) production in the rumen. Fumarate-reducing bacteria convert fumarate to succinate by fumarate reductase, ultimately leading to the production of propionate. Fumarate-reducing bacteria in the genus Enterococcus were isolated from rumen fluid samples from slaughtered Korean native goats. The enterococci were identified as Enterococcus faecalis SROD5 and E. faecium SROD by phylogenetic analyses of 16S rRNA gene sequences. The fumarate reductase activities of the SROD5 and SROD strains were 42.13 and 37.05 mM NADH oxidized/min/mg of cellular nitrogen (N), respectively. Supplementation of rumen fermentation in vitro with the SROD5 and SROD strains produced significantly higher propionate, butyrate, and total volatile fatty acid (VFA) concentrations than controls at 12 h; VFA concentrations tended to increase after 24 h of incubation. The generated CH₄ concentration was significantly lower in the SROD5 and SROD treatment groups after 24 h of incubation. These findings indicate that E. faecium SROD has potential as a direct-fed microbial additive for increasing total VFAs while decreasing CH₄ production in rumen fermentation in vitro.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.4
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• pp.488-500
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• 2013

The objective of this study was to compare the effectiveness of the protocols for superstimulation of follicular growth in Thai native heifers. Heifers (n = 20) were randomly divided into four groups of five heifers/group. Heifers were given a single dose by i.m. administration of 100 mg Follicle Stimulating Hormone dissolved in polyvinylpyrrolidone (FSHp) at 24 h. Ovum pick up (OPU) occurred at 72 h ($F_{24}O_{72}$ protocol; Group 1) or 96 h ($F_{24}O_{96}$ protocol; Group 2), and at 36 h and OPU at 72 h ($F_{36}O_{72}$ protocol; Group 3) or 96 h ($F_{36}O_{96}$ protocol; Group 4) after follicular ablation. The dynamics of ovarian follicular growth were monitored by twice-daily ultrasonographic examinations. Blood sample collections were performed every 12 h after initiation of treatment for assessment of FSH, E2 and P4 profiles. All heifers were subjected to eight repeated sequential sessions of OPU. The follicular deviation commenced $24{\pm}5.32$ h after follicular ablation in all groups. The circulatory FSH surged quickly from 24 to 36 h (>0.8 ng/ml) after follicular ablation and circulatory estrogen levels steadily increased from 36 h until OPU in all groups. At the end of the OPU sessions, the mean number of aspirated follicles/heifer/session in $F_{36}O_{72}$ protocol (Group 3) and $F_{36}O_{96}$ protocol (Group 4) were higher than in the two other groups (p<0.05). The number of cumulus-oocyte complexes (COCs), cleaved and day 8 blastocysts rates in the $F_{36}O_{72}$ protocol (Group 3) were higher than in the other groups (p<0.05). It can be concluded that a single dose i.m. administration of 100 mg FSHp at 36 h and OPU at 72 h after follicular ablation ($F_{36}O_{72}$ protocol; Group 3) was the most effective protocol for superstimulation of follicular growth for repeated OPU and subsequent in vitro embryo production in Thai native heifers.

• Korean Journal of Acupuncture
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• v.28 no.3
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• pp.33-41
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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 LPS-induced 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 LPS-induced RAW 264.7 were measured by dihydrorhodamine 123 assay after 20, 24, 28, 44, 48, and 52 h incubation at the concentrations of 10, 25, 50, and 100 ug/mL. Results : SK significantly increased hydrogen peroxide production in LPS-induced RAW 264.7 cells for 20, 24, 28, 44, 48, and 52 h incubation at the concentrations of 10, 25, 50, and 100 ug/mL (P < 0.05). But SC did not represent any significant effect on hydrogen peroxide production in LPS-induced RAW 264.7 cells. Conclusions : These results suggest that Scutellariae Radix, especially produced from South Korea, has the immune-enhancing property related with its increasement of bacteriocidal hydrogen peroxide production in LPS-induced macrophages.

• Applied Biological Chemistry
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• v.40 no.1
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• pp.58-64
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• 1997

$H_2$ production by Chromatium sp., a large purple sulfur bacterium blooming in lake Kaiike, under various environmental conditions was examined. Chromatium sp. produced $H_2$ only in the presence of light and $H_2$. Maximum $H_2$ production ($0.01\;{\mu}mol/hr/(mg\;dry\;cell\;weight)$) was obtained in the solution of 20 mg $H_2S-S/l$ under low light intensity (1000 lux) at $30^{\circ}C$. $H_2$ production was severely inhibited by the presence of $N_2\;or\;NH_4^+$. The rate observed for Chromatium sp. was relatively low compared to that of other phototrophic bacteria. Chromatium sp. is probably a most potent Ha producing species in lake Kaiike, since the bacterium readily produced $H_2$ photoautotrophically even at low light intensities by the application of suboptimal $H_2$ concentrations. Based on the photoautotrophic characteristics of bacterial $H_2$ production, it is suggested that Chromatium sp. can be an economic and practical species for biological $H_2$ production system, particularly in temperate region.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.1
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• pp.56-64
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• 2011

This study was conducted to evaluate the use of exogenous enzymes as a potential means of improving the ruminal digestion (i.e., degradability) of alfalfa hay and rice straw. Twenty six enzyme-additives were examined in terms of protein concentration and enzymic activities on model substrates. The exogenous enzymes contained ranges of endoglucanase, xylanase, ${\beta}$-glucanase, ${\alpha}$-amylase, and protease activities. Six of the enzyme additives were chosen for further investigation. The enzyme additives and a control without enzyme were applied to mature quality alfalfa hay substrate and subsequently incubated in rumen batch cultures. Five of the enzyme additives (CE2, CE13, CE14, CE19, and CE24) increased total gas production (GP) at 48 h of incubation compared to the control (p<0.05). The two additives (CE14 and CE24) having the greatest positive effects on alfalfa hay dry matter, neutral detergent fibre (NDF) and acid detergent fibre (ADF) degradability were further characterized for their ability to enhance degradation of low quality forages. The treatments CE14, CE24, a 50:50 combination of CE14 and CE24 (CE14+24), and control (no enzyme) were applied to mature alfalfa hay and rice straw. For alfalfa hay, application of the two enzyme additives, alone and in combination, increased GP compared to the control at 48 h fermentation (p<0.05), whereas only CE14 and CE14+24 treatments improved GP from rice straw (p<0.05). Rumen fluid volatile fatty acid concentrations throughout the incubation of rice straw were analyzed. Acetate concentration was slightly lower (p<0.05) for CE14${\times}$CE24 compared to the control, although individually, CE14 and CE24 acetate concentrations were not different from the control. Increases (p<0.05) in alfalfa hay NDF degradability measured at 12 and 48 h of incubation occurred only for CE14 (at 12 h) and for CE14+24 (at 12 and 48 h). Similarly, ADF degradability increased (p<0.05) with CE14 and CE14+24. As for rice straw, increased DM degradability was observed at 12 and 48 h of incubation for all enzyme treatments with an exception for CE14 at 12 h. The degradability of NDF was improved by all the enzyme treatments at either incubation time, while ADF degradability was only enhanced at 48 h. Overall, the enzymes led to enhanced digestion of mature alfalfa and there was evidence of improved digestibility of rice straw, an even lower quality forage.

• Korean Journal of Food Science and Technology
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• v.21 no.1
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• pp.120-126
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• 1989

Streptococcus diacetylactis and Leuconostoc cremoris were isolated from commercial culture and the effects of culture conditions on the diacetyl production by these strains and their mixture(1:1) were investigated. Optimum temperatures and culture times for the diacetyl production by Str. diacetylactis, Leu, cremoris and their mixture were 60hr at $22^{\circ}C$(diacetyl content, 2.24ppm), 48hr at $22^{\circ}C$(2.29ppm) and 48hr at $22^{\circ}C$ (2.21ppm), respectively Optimum initial pH for the diacetyl production by Str. diacetylactis, Leu. cremoris and the mixture were all 4.8(4.32, 6.66, 7.30ppm, respectively) and optimum sodium citrate concentrations(%, w/v) were 0.30(2.58ppm), 0.1(2.54ppm) and 0.1(2.52ppm), respectively. The diacetyl contents were gradually increased according as inoculation rates(%, w/v) were increased. The amounts of diacetyl produced under optimum conditions at 24hr incubation by Str. diacetylactis, Leu. cremoris and the mixture were 4.40, 6.59 and 7.25ppm, respectively. The most effective factor affecting diacetyl production under optimum condition was pH.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.109-109
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• 2018

Bacillus subtilis B22, a chemotrophic and aerobic bacterial strain was isolated from homemade kimchi, identified by 16S rRNA gene sequencing. B22 was primarily screened by biochemical, carbon source utilization tests. B22 was used to produce pectinase and ${\beta}$-glucosidase by submerged fermentation under different light sources. B22 was incubated in pectin media and basal media (pH 7.0) under blue, green, red and white light-emitting diodes (LEDs), fluorescent white light, and in darkness at $37^{\circ}C$, orbital shaker 150 rpm for 24 hours. Fermentation under blue LEDs maximized pectinase production ($71.59{\pm}1.6U/mL$ at 24 h) and ${\beta}$-glucosidase production ($56.31{\pm}1.6U/mL$ at 24 h). Further, the production of enzyme increased to pectinase ($156{\pm}1.28U/mL$) and ${\beta}$-glucosidase ($172{\pm}1.28U/mL$) with 3% glucose as a carbon source. Activity and stability of the partially purified enzymes were higher at pH 6.0 to 8.0 and $25-55^{\circ}C$. The effect on the metal ions $Na^+$ and $K^+$ and (moderateactivity) $Mn^{2+}$ and $Ni^{2+}$ increased activity, while $Hg^{2+}$, $Cu^{2+}$, $Fe^{2+}$, and $Fe^{2+}$ inhibited activity. EDTA, phenylmethylsulfonyl fluoride and 5,5-dithiobis (2-nitrobenzoicacid) reduced activity, while tetrafluoroethylene and 1,10-phenanthroline inhibited activity. The amylase was highly tolerant of the surfactants TritonX-100, Tween-20, Tween-80 and compatible with organic solvents methanol, ethanol, isoamylalcohol, isopropanol, t-butylalcohol and the oxidizing agents hydrogen peroxide, sodium perborate and sodium hypochlorite, although potassium iodide and ammonium persulfate reduced activity. These properties suggest utility of pectinase and ${\beta}$-glucosidase produced by B. subtilis B22 under blue LED-mediated fermentation for industrial applications.