• Microbiology and Biotechnology Letters
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• v.20 no.4
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• pp.430-436
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• 1992

Hydrogen evolution by mixed fermentation of Clostn"dium butyn"cum and photosynthetic bacteria which were capable of consuming clostridial metabolites and evolving hydrogen was investigated. Acetate and butyrate formed from anaerobic clostridial fermentation were efficiently utilized by Rhodopseudomonas sPhaeroides K-7. For complete bioconversion of clostridial metabolites such as acetate and butyrate into hydrogen, mixed culture of both anaerobic organisms forming molecular hydrogen was performed. By the mixed culture, the yield of hydrogen production increased by 20 to 75% and the levels of clostridial metabolites such as acetate, butyrate decreased in the fermentation broth. Influence of cell mixing ratio. mixing time and inoculum level on hydrogen evolution by mixed culture were examined. And then cometabolic pattern compared with in pure culture was observed as time course.

• Journal of Life Science
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• v.22 no.11
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• pp.1571-1586
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• 2012

On earth, there are about 5,400 kinds of mammals, of which about 1,000 kinds are herbivores. Among herbivores, about 250 kinds are known to be ruminants. As for cattle and sheep, which are ruminants, fermentation takes places mainly in their rumen; in contrast, for pigs and men, which are non-ruminants, fermentation takes place mainly in their caecum, colon, and rectum. As for the kind and dominance of rumen microorganisms, Bacteroidetes account for 51% and Firmicutes for 43%. As for the dominance of the large intestine microorganisms in men, Firmicutes account for 65% and Bacteroidetes for 25%. Cell wall components are decomposed by microorganisms, and short chain fatty acids (SCFAs) are generated through fermentation; the ratio of acetate, propionate, and butyrate generate is 60:25:15. Butyrate absorbed through the primary butyrate transporter MCT1 (mono carboxylate transports-1) in the intestines activates such SCFA receptors as GPR43 and GPR41. Butyrate has a strong anti-tumorigenic function. Butyrate is characterized by the fact that it has an effect on many cancer cells, contributes to the coordination of functions in the cells, and induces cancer apoptosis. Butyrate activates caspase but inhibits the activity of HDAC (histone deacetylase), so as to induce apoptosis. In addition, it increases p53 expression, so as to induce cell cycle arrest and apoptosis. Anti-inflammation actions of SCFA include the reduction of IL-8 expression in intestinal epithelial cells, the inhibition of NO synthesis, and the restraint of the activity of NF-${\kappa}B$ (nuclear factor ${\kappa}B$), so as to suppress the occurrence of cancers caused by inflammation. Butyrate plays an important role in maintaining physiological functions of intestinal mucous membranes and is used as a cure for inflammatory bowel disease (IBD).

• Microbiology and Biotechnology Letters
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• v.18 no.1
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• pp.6-11
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• 1990

Hydrogen evolution from biomass-derived carbohydrates by some Clostridia and optimal culture conditions for hydrogen evolution were investigated. Among the organisms tested, Clostridium butyricum was efficient hydrogen producer with starch, xylan, pectin, cellobiose and xylose. In batch fermentation of Cl. butyricum, optimal conditions for hydrogen evolution were achieved at pH 7.0-8.5, 10-50 mM phosphate, and 2% (w/v) glucose. Total amount of molecular hydrogen evolved by the organism slightly increased at the presence of acetate (<150 mM) or butyrate (<20 mM) in the initial fermentation medium. Especially, in case of more than the above concentration of butyrate, growth and hydrogen evolution were dramatically inhibited. In the conditions were described here, 70 mmole of molecular hydrogen per mg of DCW was produced with 1%(w/v) glucose by the organism.

• Transactions of the Korean hydrogen and new energy society
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• v.27 no.5
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• pp.533-539
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• 2016

This study was performed to evaluate the characteristics of start-up of anaerobic digestion from food waste with different inoculum ratios. The hydrogen yield was similar with different inoculum ratios. The hydrogen production rate increased with increasing inoculum ratio. But the specific hydrogen production rate decreased with increasing inoculum ratio. Total volatile fatty acids composition analysis showed that butyrate and acetate were the prevalent products in all reactors, followed by lactate and propionate. The acetate was most prevalent product in reactors at $X_0/S_0=0.080$ and 0.159. But in reactors at $X_0/S_0=0.239$ and 0.318, butyrate accounted for greater than 50% of the total volatile fatty acids.

• Transactions of the Korean hydrogen and new energy society
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• v.21 no.2
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• pp.136-142
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• 2010

Photobiological $H_2$ production was compared using purple non-sulfur bacteria Rhodobacter sphaeroides KD131 in the medium containing various organic acids as the carbon source and electron doner under illumination of $110\;W/m^2$ using halogen lamp at $30^{\circ}C$. The organic acids used were 0~120 mM acetate, butyrate, lactate and malate. Initial pH 7.0 and cell concentration 1.0 at 660nm were increased to pH 8 and 4.4~5.1, respectively during 24hrs of photo-fermentation when lactate and malate were used. However, acetate and butyrate increased pH to 9 and cell concentration to 3.2~3.9 of malate at the same experimental conditions. Optimum ranges of organic acids concentration and carbon/nitrogen ratio were 30~60 mM and 10~20, respectively. When malate was used as the substrate, maximum $H_2$ production 1.1 ml $H_2$/ml broth, which is equivalent to 1.97 mol $H_2$/mol malate was observed.

• Korean Journal of Agricultural Science
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• v.48 no.4
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• pp.957-963
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• 2021

The study aimed to investigate the effects of supplemented sodium butyrate on the in vitro rumen fermentation and growth performance of Hanwoo calves. In total, four treatments were employed according to the sodium butyrate levels: no addition (control), an addition of 0.1% (treatment 1), an addition of 0.3% (treatment 2), and an addition of 0.5% (treatment 3). After 48 hours of fermentation, the ruminal pH was found to be higher in T1 than in C. Total volatile fatty acids were significantly higher in T2 and T3 than in C. The ratio of acetate and propionate was significantly lower in T1 and T3 than in C. In this study, the optimal concentration to promote rumen fermentation was found to be 0.3%, i.e., T2, and an experiment on Hanwoo calves at a farm was conducted. However, there were no significant differences between the treatment groups in terms of the daily weight gain, feed conversion ratio, and final body weight in the feeding experiment. Also, there were no significant differences in the body length, withers height, and height at hip cross between the control and the treatment groups. The addition of 0.3% sodium butyrate was most effective at promoting in vitro rumen fermentation, but it did not significantly affect the growth performance when fed to Hanwoo calves. This indicates that the addition of sodium butyrate improved rumen fermentation but did not have a growth-promoting effect. Future studies need to compare growth and carcass performance outcomes to confirm long-term effects.

• Journal of Environmental Health Sciences
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• v.30 no.2
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• pp.149-153
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• 2004

The influences of pH on hydrogen production were also investigated over the pH range from 4.1 to 8.0 at HRT 10 hours. The hydrogen content for the produced gas was changed from 41 to 71% with corresponding pHs throughout this experiment. The produced hydrogen/carbon dioxide ratio was not vary significantly up to 6.0, then steepenly increased with increases in the pH. The maximal hydrogen yield was found to be 3.16 $\ell$/g sucrose at pH 5.0. Acetate production yield increased with increased pH, but butyrate production yield decreased with increased pH. Biomass yield increased with increased pH.

• Transactions of the Korean hydrogen and new energy society
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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 The Korean Society of Grassland and Forage Science
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• v.34 no.2
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• pp.94-102
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• 2014

This study was conducted to estimate and compare the effects of bacterial inoculants and organic acids on silage quality. Silage pH, lactate, acetate, lactate:acetate ratio, propionate, butyrate, water-soluble carbohydrate, crude protein, ammonia-N, neutral detergent fiber and acid detergent fiber (ADF) were used as parameters for quality analysis and a meta-analysis technique was employed to determine the effect size. As a data pool for analysis, we examined 14 research papers. Bacterial inoculants were found to elevate pH, lactate, acetate, lactate:acetate ratio, propionate and ADF contents compared to the controls (p<0.01). In contrast bacterial inoclulants decreased butyrate, water-soluble carbohydrate, crude protein and ammonia-N contents (p<0.01). In the organic acid treatments, all parameters except ADF showed higher contents than the control (p<0.01). In the comparison of effect sizes between the two treatments, significant differences were detected in butyrate, water-soluble carbohydrate, crude protein and ammonia-N (p<0.05). It may be concluded that bacterial inoculants could improve silage quality in terms of the aforementioned four parameters compared with organic acid treatments.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.1
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• pp.54-61
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• 2007

The influences of pH were investigated for anaerobic hydrogen gas production under the constant pH condition ranged from pH 3 to 10. Carbon dioxide and hydrogen gas were main components of the gas but methane was not detected in the produced gas when sucrose was added in enrichment medium. When the modified Gompartz equation was applied for the statistical analysis of experimental data, a hydrogen production potential and maximum gas production rate at pH 5 were 1,182 mL and 112.46 mL/g dry wt biomass/hr. The hydrogen conversion ratio was 22.56%. The butyrate/acetate ratios at pH 5 and pH 6 are 1.63 and 0.38. Higher butyrate/acetate ratio produced more hydrogen gas generation. The Haldane equation model was used to find the optimum pH and fitted well with the experimental data$(r^2=0.98)$. The optimum pH and specific hydrogen production were 5.5 and 119.61 mL/g VSS/h.