• 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.

• Animal Bioscience
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• v.34 no.1
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• pp.56-65
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• 2021

Objective: This study was conducted to investigate the effects of molasses and Lactobacillus plantarum on the ensiling quality and in vitro rumen fermentation of sudangrass silage prepared with or without wilting. Methods: The ensiling experiment, measured with 3 replicates, was carried out according to a 2×4 (wilted stages×additives) factorial treatment structure. Dry matter of the fresh (210 g/kg fresh matter) or wilted (305 g/kg fresh matter) sudangrass were ensiled (packed into 5.0-L plastic jars) without additive (control) or with molasses (M), Lactobacillus plantarum (LP), or molasses + Lactobacillus plantarum (M+LP). After 60 days of ensiling, the silages were analyzed for the chemical, fermentation, and in vitro characteristics. Results: After 60 days of ensiling, the fermentation parameters were affected by wilted, the additives and the interactions of wilted with the additives (p<0.05). The M+LP treatment at wilted had higher lactic acid levels and V-score (p<0.05) but lower pH values and butyric acid concentrations than the other treatments. In comparison with sudangrass before ensiling, after ensiling had lower dry matter and higher non-fibrous carbohydrate. The in vitro gas production, in vitro dry matter digestibility, in vitro crude protein digestibility, and in vitro acid fiber detergent digestibility changed under the effects of the additives. Significant interactions were observed between wilted and the additives in terms of in vitro gas production at 48 h, asymptotic gas production, gas production rate, half time, and the average gas production rate. The total volatile fatty acid levels in the additive treatments were higher than those in the control. Conclusion: Wilting and supplementation with molasses and Lactobacillus plantarum had the ability to improve the ensiling quality and in vitro nutrient digestibility of sudangrass silage. The M+LP treatment at wilted exhibited the strongest positive effects on silage quality and in vitro ruminal fermentation characteristics.

• The Korean Journal of Food And Nutrition
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• v.25 no.4
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• pp.878-887
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• 2012

This study investigated the fermentative characteristics and immunomodulating activity in Kimchi added with various salts (salt replacement and herb-salt with Acanthopanax senticosus and Glycyrrhizae uralensis) for the reduction of Na concentration in Kimchi. Kimchi using a salt replacement and herb-salt showed a higher level of acidity (0.8~0.84%) than that of the control (0.7%) at 7-day fermentation. Kimchi using a salt replacement and herb-salt showed a lower level of salinity (1.72~1.98%) than that of control (2.3~2.57%) during fermentation. The growth of Lactobacillus spp. and Leuconostoc spp. recorded the highest level ($2.3{\times}10^8$ and $2.8{\times}10^6cfu/g$, respectively) in control at 6 day-fermentation. However, those levels in Kimchi prepared with salt replacement and herb-salt were $3.5{\sim}5.4{\times}10^8$ and $6.1{\times}10^6cfu/g$, respectively. It is assumed that the high level of acidity of Kimchi prepared with salt replacement and herb-salt was caused by the increase in the growth of Lactobacillus spp. and Leuconostoc spp.. When the macrophage stimulating activity of salt replacement kimchi (Salt-R kimchi) supplemented with hot-water extract from Acanthopanax sentisus (AS) or Glycyrrhiza uralensis (GU) was investigated on aging period, Salt-RA kimchi with AS 5% at 6 days (2.78-fold of saline control at $100{\mu}g/m{\ell}$) and Salt-RG kimchi with GU 5% at 9 days (2.02-fold) significantly increased compared to the Salt-RA kimchi without AS or GU. In addition, Salt-RAG kimchi with AS 3% and GU 3% improved the bitter taste of Salt-RA and potently stimulated the macrophage at 6 days (1.28-fold of Salt-R kimchi) even though its activity was lower than Salt-RA (5%, 1.39-fold).

• Journal of Dairy Science and Biotechnology
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• v.32 no.2
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• pp.111-119
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• 2014

This study was carried out to investigate the quality characteristics and antioxidant activity of a functional drink prepared by mixed fermentation of oak mushroom extract and whey. As the ratio of oak mushroom extract increased, the pH value of the whey fermentative solution decreased proportionally, and the titratable acidity increased significantly. The number of lactic acid bacteria after 24 hours of culture was at a level of $10^{11}CFU/mL$ in all whey fermentative solutions containing oak mushroom extracts. DPPH and ABTS radical scavenging activities after 24 hours of culture were higher in a fermentative solution containing oak mushroom extract than in the control. After 24 hours of culture, the nitric oxide production in whey fermentation solution by LPS-induced RAW 264.7 cells was lower compared to that in whey fermentation solution with oak mushroom. Sensory evaluation revealed that, color, flavor, taste, and overall acceptability of the whey fermentation solution sample, which contained 1.0% oak mushroom extract, were much better than those of the other groups. Sensory evaluation of a whey drink containing oak mushroom flavor indicated that the whey drink containing 0.001% oak mushroom flavor was better than the other samples.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.9
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• pp.1255-1259
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• 2004

The objective of this study was to evaluate the effects of halogenated compounds, organic acids, unsaturated fatty acids and their mixtures on in vitro methane production and fermentative characteristics of mixed rumen microorganisms. Agents used in two in vitro experiments were bromoethanesulfonic acid (BES) and pyromellitic diimide (PMDI) as halogenated compound, fumarate and malate as organic acid, and linoleic acid and linolenic acid as unsaturated fatty acid sources. Ruminal fluid collected from a Holstein steer fed tall fescue and concentrate mixtures was incubated at $39^{\circ}C$ for 48 h with addition of those materials. Single supplementation of halogenated compounds, organic acids or unsaturated fatty acids decreased in vitro methane production (p<0.05). The second experiment was designed to investigate effects of combination of one of halogenated compounds and either organic acids or fatty acids on methane production. Lower concentration of methane and lower A:P ratio were observed with PMDI compared with BES (p<0.01). In general medium pH, VFA, total gas and hydrogen production, and dry matter degradability were affected by addition of the same compounds. In addition, PMDI+malate treatment resulted in the highest molar proportion of propionate, and lowest A:P ratio and methane production (p<0.01). Hydrogen production was highest in PMDI+linolenic acid and lowest in BES+malate treatment (p<0.01). PMDI+malate combination was the most recommendable in reducing methane production without too much influence on digestibility under conditions of present studies.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.2
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• pp.215-222
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• 1997

Ten rice varieties were planted at two locations (lowland and highland), during the wet and dry seasons of different years. In vivo digestibility and voluntary intake of the straw, were determined in groups of fat-tail sheep, supplemented with $18g{\cdot}kg^{-0.75}$ concentrate DM, containing ~20% crude protein. Voluntary intake of digestible straw organic matter (DOMI) consistently varied from 15.2 to $20.9g{\cdot}kg^{-0.75}$ between straw varieties, averaged over locations, years and seasons, despite considerable variation between individual batches. This variation in the nutritive value of the straw was independent of straw and grain yield, so it would seem that there is scope for selection of rice varieties with straw of higher nutritive value. The variation in DOMI of straw among location of growth, year and season, was of a magnitude similar to the improvement brought about by urea-ammoniation. The in sacco degradation characteristics and digestibility of rice straw residues were superior to those of the offered straw. This can be attributed to a preference for rice straw leaves relative to stems. Averaged over location of growth, year and season, characteristics of in sacco degradation, i.e. the rate of fermentative degradation and the truly undegradable fraction, emerged as accurate predictors of the nutritive value of rice straw.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.9
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• pp.1248-1254
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• 2012

The effect of silage additives on ensiling characteristics and nutritive value of Napier grass (Pennisetum purpureum) silages was studied. Napier grass silages were made with no additive, fermented juice of epiphytic lactic acid bacteria (FJLB), molasses or cassava meal. The ensiling characteristics were determined by ensiling Napier grass silages in airtight plastic pouches for 2, 4, 7, 14, 21 and 45 d. The effect of Napier grass silages treated with these additives on voluntary feed intake, digestibility, rumen fermentation and microbial rumen fermentation was determined in 4 fistulated cows using $4{\times}4$ Latin square design. The pH value of the treated silages rapidly decreased, and reached to the lowest value within 7 d of the start of fermentation, as compared to the control. Lactic acid content of silages treated with FJLB was stable at 14 d of fermentation and constant until 45 d of ensiling. At 45 d of ensiling, neutral detergent fiber (NDF) and acid detergent fiber (ADF) of silage treated with cassava meal were significantly lower (p<0.05) than the others. In the feeding trial, the intake of silage increased (p<0.05) in the cow fed with the treated silage. Among the treatments, dry matter intake was the lowest in the silage treated with cassava meal. The organic matter, crude protein and NDF digestibility of the silage treated with molasses was higher than the silage without additive and the silage treated with FJLB. The rumen parameters: ruminal pH, ammonia-nitrogen ($NH_3$-N), volatile fatty acid (VFA), blood urea nitrogen (BUN) and bacterial populations were not significantly different among the treatments. In conclusion, these studies confirmed that the applying of molasses improved fermentative quality, feed intake and digestibility of Napier grass.

• Microbiology and Biotechnology Letters
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• v.6 no.2
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• pp.51-57
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• 1978

The study was made of the cultural condition and physiological characteristics of the symbiotic pair of microorganisms, Cellulomonas flavigena and the second organism. It also contains the results of a taxonomical study of the second organism. The results obtained wers summarized as follows : 1) Cell yield of the mixed culture, Cellulomonas and the second organism, was higher than that of each pure culture in CM-Cellulose medium. 2) The taxonomical characteristics of the second organism revealed that it probably belonged to the genus Sporocytophaga because it had a gliding motility and microcyst. 3) Optimum pH of the mixed culture was found to be in the vicinity of 7.2, and optimum temperature of the cell growth in the mixed culture was observed to be in the vicinity of 30$^{\circ}C$. 4) It was found that the majority of the population during growth in the mixed culture consisted of Cellulomonas flavigena. 5) Cellulomonas flavigena required thiamine and biotin as growth factors but Sporocytophaga sp. had no requirement of vitamins. 6) Gulucose was not found in detectable amounts in the medium of Cellulomonas flavigena but it was traced in the mixture by thin layer chromatography. 7) Sixteen amino acids were analyzed from the cell protein of Cellulomonas flavigena by amino acid autoanalyzer. The amount of the leucine, valine and arginine was very high.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.6
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• pp.1009-1015
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• 2000

Fermentative and antioxidative characteristics of red mustard leaf (RML) kimchi, a traditional, fermented Korean vegetable food, were investigated. For the study, RML kimchi was made of RML, with green onion, red pepper, garlic, ginger, and sugar, and fermented at 15$^{\circ}C$. The pH was decreased and total acidity was increased during fermentation. The contents of reducing sugar, total vitamin C, and total Phenol content were 2.36%, 65 mg%, and 59 mg% at the initial stage. Although the content of reducing sugar decreased gradually during fermentation, however, the quantity of ascorbic acid decreased with the tendency of slightly increased at 6 days, and the amount of total phenol was increased. CIE L*, a*, b＊values were increased until 6 days of the fermentation. In order to determine the antioxidative activity of RML kimchi itself, the model systems of RML kimchi were made with cooked beef. TBA values of RML kimchi which was fermented for 6 days showed the lowest level in model systems. Water, n-hexane, methanol extracts of RML kimchi had a considerable antioxidative activity with the inhibition of formation of peroxide during the autoxidation of linoleic acid mixtures in aqueous model systems.

• Journal of Microbiology and Biotechnology
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• v.28 no.8
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• pp.1260-1269
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• 2018

Production of good Koji primarily depends upon the selection of substrate materials and fermentative microflora, which together influence the characteristic flavor and aroma. Herein, we performed comparative metabolomic analyses of volatile organic compounds (VOCs) and primary metabolites for Koji samples fermented individually with Bacillus amyloliquefaciens and Aspergillus oryzae. The VOCs and primary metabolites were analyzed using headspace solid phase microextraction (HS-SPME) followed by gas chromatography time-of-flight mass spectrometry (GC-TOF-MS). In particular, alcohols, ketones, and furans were mainly detected in Bacillus-fermented Koji (Bacillus Koji, BK), potentially due to the increased levels of lipid oxidation. A cheesy and rancid flavor was characteristic of Bacillus Koji, which is attributable to high content of typical 'off-flavor' compounds. Furthermore, the umami taste engendered by 2-methoxyphenol, (E,E)-2,4-decadienal, and glutamic acid was primarily detected in Bacillus Koji. Alternatively, malty flavor compounds (2-methylpropanal, 2-methylbutanal, 3-methylbutanal) and sweet flavor compounds (monosaccharides and maltol) were relatively abundant in Aspergillus-fermented Koji (Aspergillus Koji, AK). Hence, we argue that the VOC profile of Koji is largely determined by the rational choice of inocula, which modifies the primary metabolomes in Koji substrates, potentially shaping its volatolome as well as the aroma characteristics.