• Journal of Korean Society of Environmental Engineers
• /
• v.27 no.9
• /
• pp.958-964
• /
• 2005

Experiment was conducted to investigate the amount of hydrogen gas and the characteristics of organic acids production from various carbohydrates by anaerobic bacteria. The variation characteristics of organic acids and hydrogen gas production at the fermentative culture were also studied in the presence of heavy metals such as cadmium or lopper. 3.43 mole hydrogen per mole of hexose was produced when sucrose was used as a carbon source. Acetic acid and butyric acid were main products by the anaerobic fermentation. Hydrogen production rate was decreased and formation of acetic acid was increased as the concentration of heavy metals was increased in the medium. The inhibition of hydrogen production by the copper was more serious than the cadmium.

• Proceedings of the Korean Society for Applied Microbiology Conference
• /
• 1986.12a
• /
• pp.509.2-509
• /
• 1986

Owing to the growing interest in the production of fuels and chemicals from biomass the well-know butanol-acetone fermentation as carried out by Clostridium acetobutylicum has been intensely studied again in recent years. Several solvent-yielding fermentation processes were established which are operated by using batch cultures or continuous cultures. 1 could be shown that under conditions of phosphate limitation an asporogenous mutant of C. acetobutylicum establishes itself in a chemostat which produces the solvents continuously. Attempts have been made to change the butanol/acetone ratio in favor of butanol production. A corresponding shift of the product spectrum can be achieved by carbon monoxide addition to the head space of the fermentation (B.H. Kim et al., App. Envioron. Microbiol. 48, 764-770 1984) or by iron limitation. Progress has been made in understanding the mechanism underlying the shift from acid to solvent prodcction. Experimental results are in agreement with the view that intracellular accumulation of acetic and butyric acid results in a shortage of phosphate and coenzyme A. This shortage may serve then as signal for the synthesis of the enzymes involved in the formation of acetone and butanol.

• Asian-Australasian Journal of Animal Sciences
• /
• v.14 no.11
• /
• pp.1568-1579
• /
• 2001

This study is aimed at evaluating the effect of Aspergillus oryzae fermentation extract (AFE) on corn silage fermentation characteristics. Trial included two groups of treatments, with or without AFE inclusion in corn ensilage. Sixty corn silage containers, including two treatments with thirty replicates each, were processed in a laboratory scale mini-silo of 21 cm radius by 45 cm height. Three replicate containers were opened and sampled for analysis at 0, 0.5, 1, 2, 3, 4, 6, 10, 18 and 34 days after being ensiled. One silage container from each treatment was installed with a remote controlled electronic thermometer to record the temperature changes. Analysis included silage temperature, pH, fermentation acids, the water-soluble carbohydrates and chemical compositions and the silage protein fractions. Results showed that on the first day, the temperature of the ensiled corn was slightly higher than room temperature, but returned to room temperature on the second day. The pH and concentrations of WSC, ADF, lignin and acetic acid in the AFE treated silage were significantly lower than the control groups (p<0.05). The lactic acid and crude protein on the other hand were significantly higher in the AFE treated silage as compared to the control (p<0.05) at the end of the ensilage period. The DM content was significantly higher (p<0.05) whereas the butyric acid content of the AFE treated silage was significantly lower (p<0.05) than the control at the end of the 34 day ensilage period. Titratable acid and buffering capacity in the corn silage were not significantly different between treatment groups (p>0.05). Ammonia N concentration in the AFE treated silage showed a trend of decrease (p>0.05). NPN and the protein fraction A in both groups increased during the conservation period, but fraction A in the AFE treated corn silage was significantly higher than the control silage (p<0.05). During the conservation period, the AFE treated corn silage showed a trend toward a decrease in fractions $B_1$, $B_3$ and C (p<0.05). The protein fraction B2 showed a trend toward increase in the control group and an inconsistent trend in the AFE treated silage during the ensiling period. The AFE treated silage showed a better Flieg score over the control silage (97 vs. 75) as calculated from the concentrations of lactic acid, acetic acid and butyric acid.

• Asian-Australasian Journal of Animal Sciences
• /
• v.32 no.6
• /
• pp.783-791
• /
• 2019

Objective: This study was to evaluate the fermentation dynamics, structural and nonstructural carbohydrate composition and in vitro gas production of rice straw ensiled with lactic acid bacteria and molasses. Methods: Fresh rice straw was ensiled in 1-L laboratory silos with no additive control (C), Lactobacillus plantarum (L), molasses (M) and molasses+Lactobacillus plantarum (ML) for 6, 15, 30, and 60 days. After storage, the silages were subjected to microbial and chemical analyses as well as the further in vitro fermentation trial. Results: All additives increased lactic acid concentration, and reduced pH, dry matter (DM) loss and structural carbohydrate content relative to the control (p<0.05). The highest organic acid and residual sugar contents and lignocellulose reduction were observed in ML silage. L silage had the highest V-score with 88.10 followed by ML silage. L and ML silage improved in vitro DM digestibility as compared with other treatments, while in vitro neutral detergent fibre degradability (IVNDFD) was increased in M and ML silage (p<0.05). M silage significantly (p<0.05) increased propionic acid (PA) content and decreased butyric acid content and acetic acid/PA as well as 72-h cumulative gas production. Conclusion: The application of ML was effective for improving both the fermentation quality and in vitro digestibility of rice straw silage. Inclusion with molasses to rice straw could reduce in vitro ruminal gas production.

• Animal Bioscience
• /
• v.37 no.7
• /
• pp.1185-1195
• /
• 2024

Objective: This meta-analysis aimed to evaluate the impact of wilted and unwilted silage on various parameters, such as nutrient content, fermentation quality, bacterial populations, and digestibility. Methods: Thirty-six studies from Scopus were included in the database and analyzed using a random effects model in OpenMEE software. The studies were grouped into two categories: wilting silage (experiment group) and non-wilting silage (control group). Publication bias was assessed using a fail-safe number. Results: The results showed that wilting before ensiling significantly increased the levels of dry matter, water-soluble carbohydrates, neutral detergent fiber, and acid detergent fiber, compared to non-wilting silage (p<0.05). However, wilting significantly decreased dry matter losses, lactic acid, acetic acid, butyric acid, and ammonia levels (p<0.05). The pH, crude protein, and ash contents remained unaffected by the wilting process. Additionally, the meta-analysis revealed no significant differences in bacterial populations, including lactic acid bacteria, yeast, and aerobic bacteria, or in vitro dry matter digestibility between the two groups (p>0.05). Conclusion: Wilting before ensiling significantly improved silage quality by increasing dry matter and water-soluble carbohydrates, as well as reducing dry matter losses, butyric acid, and ammonia. Importantly, wilting did not have a significant impact on pH, crude protein, or in vitro dry matter digestibility.

• Food Science and Preservation
• /
• v.19 no.4
• /
• pp.594-603
• /
• 2012

This study developed a high-utility type of vinegar from Rubus coreanus by optimizing its fermentation conditions. In the alcohol fermentation process, the optimal conditions for the maximization of the alcohol contents were an initial sugar concentration of 15 $^{\circ}Brix$, a temperature of $30^{\circ}C$ and 4 days. The optimal conditions for the acetic acid fermentation were 9 days of fermentation at $30^{\circ}C$ and 200 rpm, with 6% alcohol and 2% initial acidity. The sucrose, fructose, and glucose contents were 952.90, 491.01, and 386.62 mg%, respectively. The free organic acids were acetic, malic, succinic, malonic, oxalic, and lactic acids. The total free amino acid content was 104.33 ${\mu}g/mL$, with alanine, glutamic acid, ${\gamma}$-amino-N-butyric acid, and o-phospho-ethanolamine as the major amino acids. The K, Na, and Mg contents were 1,686.10, 172.50, and 69.33 ppm, respectively. The total phenolic and anthocyanin contents were 25.19 and 80.71 mg/100 mL, respectively. The DPPH- and $ABTS^{.+}$ radical scavenging activities were approximately 65 and 94%, respectively. Moreover, the vinegar's ${\beta}$-carotene bleaching activity and reducing power showed that it had strong anti-oxidant properties. These results show that Rubus coreanus vinegar has anti-oxidant properties and may be used as functional food.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.37 no.1
• /
• pp.10-18
• /
• 2017

A total of nine Korean indigenous goats were used in a cross-over arrangement to give nine replicates per treatment, and they were housed individually assigned to 1 of 9 dietary treatments. Nine treatments were 0, 500, and 1000 ppm of quercetin supplementation in diets by mixing roughage and concentrate with different ratios (RC ratio) of 3:7 (RC 30), 5:5 (RC 50) and 7:3 (RC 70). Nutrient utilizations of dry matter, crude fat and NDF were not affected by neither RC ratio nor dietary quercetin (p>0.05), but the rate of crude protein and ADF increased in animals in RC 70 group regardless of quercetin supplementation (p<0.05). In addition, higher RC ratio increased (p<0.05) N retention and N retention rate. Total VFA, acetic acid, propionic acid, iso-butyric acid, butyric acid, iso-valeric acid and valeric acid contents were not affected (p>0.05) by dietary quercetin. Meanwhile, lower total cholesterol level exhibited in animals in RC 70 group compared to RC 30 or 50 groups, unrelated to dietary quercetin (p<0.05), however other plasma parameters were not influenced (p>0.05) by RC ratio and dietary quercetin. Our results indicated that both RC ratio and dietary quercetin may not directly affect the production indices and immune responses in Korean indigenous goat.

• Journal of Environmental Science International
• /
• v.21 no.10
• /
• pp.1255-1263
• /
• 2012

Batch cultivations were performed to evaluate the influences of the initial pH condition on mesophilic and thermophilic acidogenic fermentation with food waste recycling wastewater. In both conditions of mesophilic and thermophilic fermentation, TVFAs production rates were maximized at the initial pH 7 condition as 0.15 and 0.23 g TVFAs/L hr, respectively. And pH was also maintained stably between 6 and 7 during 72hr acidogenic cultivation at both conditions. However, predominant VFA components were different according to reaction temperature conditions. In mesophilic condition, propionic acid which has low conversion efficiency to methane was accumulated up to 1,348 mg/L while acetic and butyric acid were predominant in thermophilic condition. Therefore, thermophilic acidogenic fermentation was superior for the effective VFAs production than mesophilic condition. From the DGGE analysis, the band patterns were different according to the initial pH conditions but the correlations of the each band were increased in similar pH conditions. These results mean that microbial communities were certainly affected by the initial pH condition. Consequently, the adjustment of the initial pH to neutral region and thermophilic operation are needed to enhance acidogenic fermentation of food waste recycling wastewater.

• Korean Journal of Veterinary Research
• /
• v.34 no.1
• /
• pp.99-105
• /
• 1994

Clotridium bovis sp. nov, is described on the basis of 5 strains isolated from the feces of Holstein cattle. The isolate are gram-positive, motile, strict anaerobic spore forming rods. They differ from all the validly described related species of the genus Clostridium in carbohydrate fermentation pattern, G+C mol% and DNA homologies. Acid is produced from arabinose, xylose, glucose, mannose, fructose, galactose, sucrose, maltose, cellobiose, lactose, trehalose, melibiose, raffinose, inulin and salicin. Major end products in PYFG broth are large amounts of butyric acid and lactic acid, and trace amounts of acetic and succinic acids. The G+C mol% of DNA from the type strain is 26 mol%. The type strain of Clostridium bovis is Catt $66^T$ strain.

• Journal of environmental and Sanitary engineering
• /
• v.4 no.2 s.7
• /
• pp.91-99
• /
• 1989

An anaerobic acidogenic fermentation experiment was carried out in order to investigate the distribution of volatile acid products and gas generations with varing temperatures and pH values. The experiment was carried out using $1\%$ glucose as substrate and a pair of 3.5 liter vessle as bench scale batch reactors. The reactors were operated for 7 days at 25, 30 and $35^{\circ}C$ and at pH values of 4.0, 4.5, 5.0, 5.5 and 6.0 at each temperature conditions. Major products at all experiment pH's at $35^{\circ}C$ were acetic acids and butyric acids which together composed around $90^{\circ}F$ of total product acids. At higher pH values at $35^{\circ}C$, propionic acid reached around $10\%$. At all experiment conditions, 52 to $55\%$ of generated gases comprised of hydrogen gas and 45 to $48\%$ of carbon dioxide. With temperature increase from 25 to $35^{\circ}C$, the production rate of acetic acid increased 2.9 fold, butyric acid 22 fold, hydrogen gas 2.0 fold and carbon dioxide gas 2.3 fold. Optimum reaction conditions for highest production of acetic acid and hydrogen gas was determined to be pH 5.5 at $35^{\circ}C$.