• Asian-Australasian Journal of Animal Sciences
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• v.11 no.3
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• pp.217-233
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• 1998

Milk yield and its composition is governed by level of nutrition and the composition of diet. Higher concentrate input improves milk yield, whereas its input at moderate levels improves yield of milk fat. High level of dietary protein improves dry matter intake and milk production, however, CP content above 14% has less advantage. Milk yield is enhanced by the feeding of cottonseed and soyabean meal, whereas milk fat increases by the supplementation of cottonseed. Dietary fat increases energy intake, production of milk and milk fat. Quality and quantity of feeds consumed affect fermentation patterns in rumen. Among the rumen metabolites, volatile fatty acids (VFA) content and propionate proportion have been related positively with milk yield, whereas proportion of acetate and butyrate have been related positively with milk fat content. Dietary carbohydrates through the source of sugar, starch, roughage and fibre affect VFA concentration in rumen. Therefore, concentration of volatile fatty acids could be altered to the advantage of consumer through judicious manipulation of diet.

• Korean Journal of Environmental Agriculture
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• v.13 no.3
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• pp.311-320
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• 1994

This study was conducted to investigate the biochemical properties of isolated bacteria, low temperature tolerant methane-producing clostridia which were selected for using them as inoculum to anaerobic fermentation of agricultural and livestock wastes at low temperature. The results were; 1. Low temperature tolerant methane-producing clostridia were isolated from the samples which showed the high methanogenesis rate by enrichment culture at low temperature in cellulose medium. These clostridia, Clostridium botulinum SRC-64, Clostridium scatologens SRC-91 and Clostridium tyrobutyricum SRC-100, were isolated from swampy sediment at latitude $56.9^{\circ}N$, lake sediment IV at latitude $55.0^{\circ}N$, and tidal land soil II at latitude $37.0^{\circ}N$, respectively. The optimum growth temperature for these isolates was $37^{\circ}C$ and the minimum, around $10^{\circ}C$. They all had detectable amount of $F_{420}$, specific coenzyme of methanogens. 2. As anaerobic fermentation products of glucose SRC-64 produced $H_2$, acetic, isovaleric and caproic acid, SRC-91 produced $H_2$, propionic, butyric, valeric, and caproic acid, and SRC-100 produced only acetic and propionic acid. The isolates were produced $CH_4$ ranged from 2.6 to 8.68 n moles/ml for 2 days at $13^{\circ}C$.

• Journal of Environmental Health Sciences
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• v.33 no.5
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• pp.403-407
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• 2007

The inhibitory effect of the food processing agent on growth of Escherichia coli O157:H7, Salmonella Enteritidis, and Listeria monocytogenes was performed with organic acid, and combination of citric acid, acetic acid, propionic acid and vanillic acid. The minimun inhibitory concentration(MIC) of propionic acid was 5,000 ppm in E. coli O157:H7, 2,500 ppm in Salmonella Enteritidis and Listeria monocytogenes. MIC of citric acid was 10,000 ppm in E. coli O157:H7 and Salmonella Enteritidis, 2,500 ppm in Listeria monocytogenes. MIC of acetic acid was 2,500ppm, while in vanillic acid was 5,000 ppm in Escherichia coli O157:H7, Salmonella Enteritidis, and Listeria monocytogenes. MIC of combined organc acid in E. coli O157:H7 were 2,500ppm in PC, 1,250 ppm in PA, PV, CA, CV and AV. MIC of combined organc acid in Salmonella Enteritidis were 2,500 ppm in PC, PA, PV, CA, and CV, 1,250 ppm in AV. MIC of combined organc acid in Listeria monocytogenes were 1,250 ppm in all treatment group. MIC of combined treatment of three organc acid in E. coli O157:H7, S. Enteritidis and L. monocytogenes were 1,250 ppm in PCA, PCV, PAV and CAV. The inhibitory effect of organc acid in E. coli O157:H7, S. Enteritidis and L. monocytogenes could be confirmed from the result of this experiment. Therefore, it was expected that the food process would increase or maintain by using organic acid.

• Restorative Dentistry and Endodontics
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• v.21 no.2
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• pp.470-488
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• 1996

The end products of the metabolism of the oral microorganism, organic acids, are an element that produces dental caries. Four organic acids in plaque fluid, lactic acid, acetic acid, succinic acid, propionic acid which take the important role in producing dental caries, were chosen to evaluate the effect of acid type and concentration. The subject, $100{\mu}m$ in thickness, were immersed in acid-buffer solution which has the different acid concentration of 10mM, 25mM, 50mM, 100mM and pH 4.3 and degree of saturation was $0.153{\pm}0.003$ kept in constant and were operated to produce artificial caries under different demineralization time (1, 2, 3 day) at x25. The results were obtained by observing under polarizing microscope at x25. 1. The subsurface lesion, specific finding of incipient enamel caries, showed positive birefringence. but surface zone and sound enamel showed negative birefringence. 2. The demineralization rate of enamel was increased as the acid concentration increased. 3. The subsurface lesion showed increasing depth in the order of lactic, acetic, propionic acid, succinic acid. 4. The concentration of organic acid in artificial caries system had an independent effect on demineralization rate in enamel under the constant pH and degree of saturation. The result of this study showed that not only pH and the acid strength but the concentration of organic acid had an independent effect on demineralization rate in early enamel caries. And through the further research on the factors influencing enamel demineralization, it will be necessary to develop an effective caries preventive therapy.

• KSBB Journal
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• v.11 no.3
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• pp.380-387
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• 1996

The growth of recombinant E. coli and formation of the by-products were investigated. Glucose was consumed in approximately 8hours of cultivation when initial glucose concentration was 5g/1. When higher initial glucose concentrations were employed, it took approximately 16 to 20hours for the glucose to be consumed. When maltose or glucose was used as a carbon source, lactic acid and acetic acid were main by-products, while propionic acid and methanol production was not significant. Much by- products were formed at the higher initial carbon source concentrations. Higher concentration of lactic acid was observed when glucose was used, while higher concentration of acetic acid was observed when maltose was used. Lactic acid production affected the cell yield while acetic acid production affected the growth rate.

• Journal of the Korea Organic Resources Recycling Association
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• v.2 no.2
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• pp.31-37
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• 1994

For a microbiological study of composting process, screening and assay method for biopolymer degrading enzymes and microorganisms were developed and for the study of the possibility of composting in anaerobic state, distribution of sulfate reducing bacteria which plays a final role in anaerobic degradation was investigated. Substrates used for the development of assay methods for biopolymer degradation are ${\beta}-glucan$, xylan, dextran, CMC(carboxy methly cellulose), casein, and collagen. These substrates were made insoluble by a cross-linking agent and linked with dye to make chromogenic substrates. ${\beta}-glucan$ and xylan substrates could substitute congo-red method for screening of polymer degrading microorganisms without damaging the colonies. Sulfate reducing bacteria contained in the sample sludge showed preference to lactic acid, propionic acid, butyric acid and formic acid and could use acetic acid and valeric acid.

• Journal of The Korean Society of Grassland and Forage Science
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• v.16 no.3
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• pp.245-252
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• 1996

This experiment was carried out to investigate the effect of feeding order bay-concentrate-silage, concentratehay- silage, silage-concentrate-hay, silage-concentrate-hay, concentrate-silage-hay) on ruminal characteristics change with 3 fistulated dry Holstein cows in a Latin square design. The main results obtained were as follows : DM intake in forage hayconcentrate-silage feeding order was 1.65% of body weight, which is the highest of all treatments, but that in concentrate-hay-silage 1.4%, which is the lowest. The difference between max and min rumen pH in hayconcentrate-silage feeding order was lowest as 0.55, but there is no significant. The mean rumen $NH_3N$ content in silage-concentrate-hay feeding order was highest as 6.12mg/100ml, but that in silageconcentrate-hay feeding order lowest as 4.82mg/100ml. Acetic acid and propionic acid content was highest in forage hay-concentrate-silage feeding order. but there is no significant. The ratio of acetic acid to propionic acid averaged 3.47~3.69(NS). In conclusion, the best feeding order fitted in ruminal physiology was forage hay-concentrate-silage.

• The Korean Journal of Food And Nutrition
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• v.8 no.3
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• pp.206-211
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• 1995

Three kinds of soy sauce were prepared using the brick type of conventional menu(A), the brick type of meju of Aspergillus oryzae (B) and the grain type of menu Aspergillus oryzae (C). Organic acid and fatty acid were analyzed In accordance to aging time of those products Citric acid, lactic acid, acetic acid, malonic acid, butyric acid, oxalic acid, and propionic acid were dejected in all kinds of soy sauce. The content of lactic acid was shown higher than those of any other organic acids. The content of lactic acid was much higher at beginning of preparation and at 180 days in soy sauce B than any other conditions. The content of acetic acid was much higher at beginning of preparation, at 120 days in soy sauce C and at 180 days in soy sauce B than any other conditions. The content of citric acid was highest at beginning preparation in soy sauce C, and that was highest in soy sauce B except beginning preparation to 120 days. Myristic, palmitic, stearic, oleic, linoliic, linolenic, arachidonic acid were detected in all kinds of soy sauce after 180 days. The content of oleic acid were shown 32.59∼53.79% in soy sauce B and in soy sauce C. The content of stearic acid was shown 49.7oA In soy sauce A. Linolinec acid and arachidonic acid were detected in only soy sauce C.

• Animal Bioscience
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• v.34 no.2
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• pp.223-232
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• 2021

Objective: To investigate the improvement in utilization efficiency of total mixed ration (TMR) on Tibetan plateau, TMR were ensiled with different additives. Methods: A total of 150 experimental silos were prepared in a completely randomized design to evaluate the six treatments: i) control (without additive), ii) Lactobacillus buchneri (L. buchneri), iii) acetic acid, iv) propionic acid, v) 1,2-propanediol; and vi) 1-propanol. After 90 days of ensiling, silos were opened for fermentation quality and in vitro analysis, and then subjected to an aerobic stability test for 14 days. Results: Treating with L. buchneri, acetic acid, 1,2-propanediol and 1-propanol decreased propionic acid contents and yeast number, whereas increased (p<0.05) pH, acetic acid and ethanol contents in the fermented TMR. Despite increased dry matter (DM) loss in the TMRs treated with 1,2-propanediol and 1-pronanol, additives did not affect (p>0.05) all in vitro parameters including gas production at 24 h (GP24), GP rate constant, potential GP, in vitro DM digestibility and in vitro neutral detergent fibre digestibility. All additives improved the aerobic stability of ensiled TMR to different extents. Specially, aerobic stability of the ensiled TMR were substantially improved by L. buchneri, acetic acid, 1,2-propanediol, and 1-propanol, indicated by stable pH and lactic acid content during the aerobic stability test. Conclusion: L. buchneri, acetic acid, 1,2-propanediol, and 1-propanol had no adverse effect on in vitro digestibility, while ensiling TMR with the additives produced more acetic acid and ethanol, subsequently resulting in improvement of aerobic stability. There is a potential for some fermentation boosting additives to enhance aerobic stability of fermented TMR on Tibetan plateau.

• Transactions of the Korean hydrogen and new energy society
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• v.30 no.3
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• pp.269-275
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• 2019

This study was conducted to evaluate the microbial communities in coupled system of a microbial electrolysis cell and an anaerobic digestion. Glucose, butyric acid, propionic acid and acetic acid were used as substrates. The maximum methane production and methane production rate of propionic acid respectively were $327.9{\pm}6.7mL\;CH_4/g\;COD$ and $28.3{\pm}3.1mL\;CH_4/g\;COD{\cdot}d$, which were higher than others. Microbial communities' analyses indicated that acetoclastic methangens were predominant in all systems. But the proportion of hydrogenotrophic methanogens was higher in the system using propionic acid as a substrate when compared to others. In coupled system of a microbial electrolysis cell and anaerobic digestion, the methane production was higher as the distribution of hydrogen, which was generated by substrate degradation, and proportion of hydrogenotrophic methanogens was higher.