• The Korea Journal of Herbology
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• v.38 no.4
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• pp.11-19
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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 and nitric oxide (NO) in RAW 264.7 mouse macrophages stimulated with polyinosinic-polycytidylic acid (poly-IC) and lipoteichoic acid. Methods : RAW 264.7 co-stimulated with poly-IC and lipoteichoic acid were incubated with baicalein at concentrations of 25 and 50 μM. Incubation time is 16 h, 18 h, 20 h, 22 h, and 24 h. After incubation, The production of hydrogen peroxide in RAW 264.7 was measured with dihydrorhodamine 123 assay. Chrysin was used as a comparative material. NO production was evaluated by griess assay. Results : For 16 h, 18 h, 20 h, 22 h, and 24 h incubation, BA at the concentration of 25 and 50 μM significantly inhibited the production of hydrogen peroxide in RAW 264.7 stimulated by poly-IC and lipoteichoic acid (p <0.001). In details, production of hydrogen peroxide in 'poly-IC and lipoteichoic acid'-stimulated RAW 264.7 treated for 16 h with BA at concentrations of 25 and 50 μM was 82.36% and 77.24% of the control group treated with poly-IC and lipoteichoic acid only, respectively; the production of hydrogen peroxide for 18 h was 83.15% and 77.91%, respectively;production of hydrogen peroxide for 20 h was 82.88% and 77.82%, respectively; production of hydrogen peroxide for 22 h was 83.27% and 78.17%, respectively; production of hydrogen peroxide for 24 h was 83.54% and 78.35%, respectively. Additionally, BA at the concentration of 50 and 100 μM significantly inhibited NO production in lipoteichoic acid-induced RAW 264.7 (p <0.001). Conclusions : BA might have anti-oxidative activity related to its inhibition of hydrogen peroxide production in 'poly-IC and lipoteichoic acid'-stimulated RAW 264.7 macrophages.

• Journal of Microbiology
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• v.45 no.3
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• pp.199-204
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• 2007

The objective of this study was to evaluate the effect of soluble carbohydrates (glucose, cellobiose), pH (6.0, 6.5, 7.0), and rumen microbial growth factors (VFA, vitamins) on biohydrogenation of linoleic acid (LA) by mixed rumen fungi. Addition of glucose or cellobiose to culture media slowed the rate of biohydrogenation; only 35-40% of LA was converted to conjugated linoleic acid (CLA) or vaccenic acid (VA) within 24 h of incubation, whereas in the control treatment, 100% of LA was converted within 24 h. Addition of VFA or vitamins did not affect biohydrogenation activity or CLA production. Culturing rumen fungi at pH 6.0 slowed biohydrogenation compared with pH 6.5 or 7.0. CLA production was reduced by pH 6.0 compared with control (pH 6.5), but was higher with pH 7.0. Biohydrogenation of LA to VA was complete within 72 h at pH 6.0, 24 h at pH 6.5, and 48 h at pH 7.0. It is concluded that optimum conditions for biohydrogenation of LA and for CLA production by rumen fungi were provided without addition of soluble carbohydrates, VFA or vitamins to the culture medium; optimum pH was 6.5 for biohydrogenation and 7.0 for CLA production.

• 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.6
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• pp.45-52
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• 2023

Objectives : Effects of baicalein (BA) on oxidative stress in RAW 264.7 mouse macrophages stimulated with peptidoglycan (PG) and lipopolysaccharide (LPS) were investigated. Methods : RAW 264.7 co-stimulated with LPS and PG were incubated with BA at concentrations of 25 and 50 µM. Incubation time was 18 h, 20 h, 22 h, 24 h, and 26 h. After incubation, the production of hydrogen peroxide in RAW 264.7 was measured with dihydrorhodamine 123 assay. Additionally, RAW 264.7 stimulated with PG were incubated with BA at concentrations of 25 and 50 µM for 24 h. After incubation, NO production was evaluated by griess reagent assay. Results : BA significantly inhibited hydrogen peroxide productions (p <0.05). In details, production of hydrogen peroxide in 'LPS and PG'-stimulated RAW 264.7 treated for 18 h with BA at concentrations of 25 and 50 µM was 91.27% and 89.22% of the control group treated with LPS and PG only, respectively; the production of hydrogen peroxide for 20 h was 92.19% and 90.58%, respectively; production of hydrogen peroxide for 22 h was 91.69% and 89.89%, respectively; production of hydrogen peroxide for 24 h was 92.4% and 90.19%, respectively; production of hydrogen peroxide for 26 h was 91.7% and 89.04%, respectively. Additionally, BA at the concentration of 50 and 100 µM significantly inhibited NO production in PG-induced RAW 264.7 (p <0.05). Conclusions : BA might have anti-oxidative activity related to its inhibition of hydrogen peroxide production in 'LPS and PG'-stimulated RAW 264.7 macrophages.

• Journal of Hydrogen and New Energy
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• v.24 no.2
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• pp.99-106
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• 2013

The variations of performance and metabolites at an early stage were investigated for the successful start-up technology in continuous fermentative hydrogen production. Unsuccessful start-up was observed when the operation mode was changed from batch to continuous mode after the yield was reached to 0.5 mol $H_2$/mol $hexose_{added}$ by batch mode. $H_2$ production continued till 12 hours accompanied by butyrate production, but did not last with propionate production increase. It was suspected that the failure was due to the regrowth of propionic acid bacteria during batch mode which were inhibited by heat-shock but not completely killed. Thus, successful start-up was tried by early switchover from batch to continuous operation; continuous operation was started after the $H_2$ yield was reached to 0.2 mol $H_2$/mol $hexose_{added}$ by batch mode. Although $H_2$ production rate decreased at an early stage, stable $H_2$ yield of 0.8 mol $H_2$/mol $hexose_{added}$ was achieved after 10 days by lowering down propionate production. And it was also concluded that the reason for $H_2$ production decrease at an early stage was due to alcohol production by self detoxification mechanism against VFAs accumulation.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.1
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• pp.68-72
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• 2004

The effects of the addition of yeast on in vitro roughage degradability and methane production were investigated in order to clarify the effects of yeast on the rumen microbes and to establish methods of rumen manipulation. Three roughages (whole crop corn, rice straw and Italian ryegrass) were incubated for 3, 6, 12 and 24 h with or without dried beer yeast following the method described by Tilley and Terry. Using the same method, these roughages were incubated with or without yeast extract, albumin or purified DNA. In vitro methane production was measured with or without dried beer yeast at 12 and 24 h. The degradability of yeast was found to be 57 and 80% at 12 and 24 h, respectively. The rate of degradation of fraction b was 6.16%/h. There was a significant increase in roughage degradability at 6 h (p<0.05), 12 h (p<0.05) and 24 h (p<0.01) by dried yeast addition. The degradability of all three roughages was higher in the samples treated with yeast extract than in the no addition samples except in the case of rice straw incubated for 12 h. Nevertheless, the magnitude of increment was smaller with the addition of yeast extract than without the addition of yeast. With the addition of purified DNA, there were significant increases in roughage degradability at 6 h (p<0.01), 12 h (p<0.01) and 24 h (p<0.05); however, higher degradability values were detected in the samples to which albumin was added, particularly at 6 h. If the degradability values of the no addition samples with those of samples containing yeast, yeast extract, DNA and albumin were compared, the largest difference was found in the samples to which yeast was added, although it is worth noting that higher values were observed in the yeast extract samples than in the DNA or albumin samples, with the exception of the case of rice straw incubated for 24 h. Methane production was significantly increased at both 12 and 24 h incubation. The increment of roughage degradation and methane production brought about by the addition of dried beer yeast to the samples was thought to be due to the activation of rumen microbes. Water soluble fraction of yeast also seemed to play a role in ruminal microbe activation. The increment of degradability is thought to be partially due to the addition of crude protein or nucleic acid but it is expected that other factors play a greater role. And those factors may responsible for the different effects of individual yeast on ruminal microbes.

• Applied Chemistry for Engineering
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• v.22 no.5
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• pp.562-565
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• 2011

In this study, we developed a bioprocess using Clostridium ljungdahlii as a biological catalyst to produce bio-ethanol, and the effect of pH on microbial growth and ethanol production was investigated. From the results of fermentation at various initial pH condition without pH control, pH of fermentation broth decreased to 4.5 within 24 h due to accumulation of by-product acetic acid and both microbial growth and ethanol production were stopped. The experimental result of initial pH 8 showed the highest microbial growth and ethanol production (0.53 g/L), since the pH drop was relatively slow. From the experiment of pH 7 maintained fermentation using pH controllable bioreactor, the maximum cell dry weight of 1.65 g/L and the maximum ethanol concentration of 1.43 g/L were obtained within 24 h. In conclusion, the C. ljungdahlii growth was enhanced by pH maintenance of neutral range, and the ethanol production was also enhanced based on the growth-associated ethanol production characteristics of C. ljungdahlii.

• The Korea Journal of Herbology
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• v.39 no.4
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• pp.37-45
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• 2024

Objectives : This study aimed to elucidate antioxidant activity of chrysin in polyinosinic-polycytidylic acid (poly-IC) and lipoteichoic acid-induced RAW 264.7 mouse macrophages. Methods : RAW 264.7 co-stimulated with poly-IC and lipoteichoic acid were incubated with chrysin at concentrations of 25 and 50 µM. Hydrogen peroxide production was measured with dihydrorhodamine 123 assay. Nitric Oxide (NO) production was evaluated by griess reagent assay. Results : For 16 h, 18 h, 20 h, 22 h, and 24 h incubation, chrysin at the concentration of 25 and 50 µM significantly suppressed hydrogen peroxide production in poly-IC and lipoteichoic acid-induced RAW 264.7. In details, production of hydrogen peroxide in 'poly-IC and lipoteichoic acid'-stimulated RAW 264.7 treated for 16 h with chrysin at concentrations of 25 and 50 µM was 83.84% and 79.3% of the control group treated with poly-IC and lipoteichoic acid only, respectively; the production of hydrogen peroxide for 18 h was 84.36% and 79.93%, respectively; production of hydrogen peroxide for 20 h was 85.68% and 80.22%, respectively; production of hydrogen peroxide for 22 h was 85.81% and 79.95%, respectively; production of hydrogen peroxide for 24 h was 86.01% and 80.18%, respectively. Additionally, chrysin at the concentration of 5, 10, 25, and 50 µM significantly inhibited NO production in THP-1 human monocytic cell line. Conclusions : Chrysin might have anti-oxidative activity related to its inhibition of hydrogen peroxide production in 'poly-IC and lipoteichoic acid'-stimulated RAW 264.7.

• Journal of Microbiology and Biotechnology
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• v.32 no.8
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• pp.1054-1063
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• 2022

Trehalose is a non-conventional sugar with potent applications in the food, healthcare and biopharma industries. In this study, trehalose was synthesized from maltose using whole-cell Pseudomonas monteilii TBRC 1196 producing trehalose synthase (TreS) as the biocatalyst. The reaction condition was optimized using 1% Triton X-100 permeabilized cells. According to our central composite design (CCD) experiment, the optimal process was achieved at 35℃ and pH 8.0 for 24 h, resulting in the maximum trehalose yield of 51.60 g/g after 12 h using an initial cell loading of 94 g/l. Scale-up production in a lab-scale bioreactor led to the final trehalose concentration of 51.91 g/l with a yield of 51.60 g/g and productivity of 4.37 g/l/h together with 8.24 g/l glucose as a byproduct. A one-pot process integrating trehalose production and byproduct bioremoval showed 53.35% trehalose yield from 107.4 g/l after 15 h by permeabilized P. moteilii cells. The residual maltose and glucose were subsequently removed by Saccharomyces cerevisiae TBRC 12153, resulting in trehalose recovery of 99.23% with 24.85 g/l ethanol obtained as a co-product. The present work provides an integrated alternative process for trehalose production from maltose syrup in bio-industry.

• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.3
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• pp.197-205
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• 2013

An in vitro study was conducted to determine the effects of defaunation (removal of protozoa) and forage sources (rice straw, ryegrass and tall fescue) on ruminal fermentation characteristics, methane ($CH_4$) production and degradation by rumen microbes. Sodium lauryl sulfate, as a defaunation reagent, was added into the mixed culture solution to remove ruminal protozoa at a concentration of 0.375 mg/ml. Pure cellulose (0.64 g, Sigma, C8002) and three forage sources were incubated in the bottle of culture solution of mixed rumen microbes (faunation) or defaunation for up to 24 h. The concentration of ammonia-N was high under condition of defaunation compared to that from faunation in all incubations (p<0.001). Total VFA concentration was increased at 3, 6 and 12 h (p<0.05~p<0.01) but was decreased at 24 h incubation (p<0.001) under condition of defaunation. Defaunation decreased acetate (p<0.001) and butyrate (p<0.001) proportions at 6, 12 and 24 h incubation times, but increased propionate (p<0.001) proportion at all incubation times for forages. Effective degradability of dry matter was decreased by defaunation (p<0.001). Defaunation not only decreased total gas (p<0.001) and $CO_2$ (p<0.01~0.001) production at 12 and 24 h incubations, but reduced $CH_4$ production (p<0.001) at all incubation times for all forages. The $CH_4$ production, regardless of defaunation, in order of forage sources were rice straw > tall fescue > ryegrass > cellulose (p<0.001) up to 24 h incubation.