• 한국식품영양학회지
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• 제6권4호
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• pp.287-293
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• 1993

This study was carried out to investigate the influences of cultural conditions of koji on the production of organic acid during rice-koji making by Aspergillus awamori var. kawachii which is now widely used as koji-mold in brewing Takju and Yakju in Korea. The optimum temperature for the germination of the conidia of the mold was 35'8, and the time required for germination at this temperature was 8 hours. Rapid germination occurred when the water content of steamed rice was above 40%, but germination retardation occurred markedly below 35%. The optimum cultural temperature for the production of organic acid was 32$^{\circ}C$, and the production of organic acid was markedly restricted at 36$^{\circ}C$ and 4$0^{\circ}C$. It was effective for the high production of both saccharogenic amylase and organic acid to shift the cultural temperature from initial 36$^{\circ}C$ to 32$^{\circ}C$ after 20~25 hours of cultivation. Initial water content suitable to the production of organic acid was 40% in steamed rice, but its production was markedly restricted below 30% of water content. When the quantity of conidial inoculation was too small, the production of organic acid was low in initial phase, but it was retrived at later period. Acid production was markedly restricted together with the increase in koji thickness.

• 한국미생물·생명공학회지
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• 제22권2호
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• pp.120-125
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• 1994

By using a synthetic medium simulated on the amino acid composition of soybeam, the effect of salt concentrations on the production of volatile organic acid by the strains of Zygosaccharomyces rouxii So-3101, a soy sauce yeast, was studied at the concentrations of 12.5, 18.0, 22.0 and 28.5% NaCl. The growth, consumption of glucose, and production of alcohol, total acid and volatile organic acid, showed the highest values at a concentration of 12.5% NaCl, and those values were decreased with an increase in the salt concentration. The ratio of volatile organic acid to total organic acid was remained at approximately the same level within the range of salt concentrations between 12.5~22.0%, whereas the ratio was decreased at a salt concentration of 28.5%. After incubation for 16 days, 8 volatile organic acids, i.e. acetic, propionic, n-butyric, isobutyric, isovaleric, isocaproic, n-caproic, and heptanoic acids, were detected by gas chromatography. Among the volatile organic acids, acetic acid was produced in the appreciable amiunt and its ratio to the other volatile acids was increased with an increase in the salt concentration.A small amount of isocaproic, propionic, isobutyric and isovaleric acids were produced, and n-caproic, n-butyric and heptanoic acids were detected only at the lower salt concentration.

• Asian-Australasian Journal of Animal Sciences
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• 제17권9호
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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.

• 한국유기농업학회지
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• 제25권2호
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• pp.461-473
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• 2017

Total mixed ration (TMR) including concentrate diet and roughage together have been used for the ruminant animal. Relatively high concentrations of moisture and water soluble carbohydrate are representative feature of TMR. Those moisture and water can also provide a niche for bacterial growth. Therefore, a possible fermentation of TMR induced by micro-organism is generally accepted. The present study hypothesized that different lactic acid bacteria could alter fermentation of TMR and subsequently rumen fermentation. Three lactic acid bacteria, Lactobacillus paracasei (A), L. plantarum (B) and L. parabuchneri (C), were employed and 7 treatments under full factorial design were compared with control without inoculation. TMR for dairy cow was used. Significant alterations by treatments were detected at lactic acid and butyric acid contents in TMR (p<0.05). Treatment AC (mixture of A and C) and BC (mixture of B and C) showed great lactate production. Great butyrate production was found at treatment C. At in vitro rumen fermentation, treatments B, C and AB (mixture of A and B) showed significantly great total gas production (p<0.05). All treatments except treatments B and AB, showed less dry matter digestibility, significantly (p<0.05). Total volatile fatty acid production at treatment AC was significantly greater than others (p<0.05). In individual volatile fatty acid production, treatment AB and AC showed great acetate and propionate productions, significantly (p<0.05). This study investigated correlation between organic acid production in TMR and rumen volatile fatty acid production. And it was found that butyric acid in TMR had significant negative correlation with acetate, propionate, total volatile fatty acid, AP ratio and dry matter digestibility.

• 대한환경공학회지
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• 제27권9호
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• pp.958-964
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• 2005

혐기성균에 의해 각종 탄수화물로부터 생성되는 수소가스의 량을 측정하였으며, 이 때 생성되는 유기산의 생성 특성을 파악하고자 하였다. 또한 이를 기초로 카드뮴과 구리와 같은 중금속이 배양액에 존재할 경우 혐기성균에 의한 수소생산량과 발효산물의 변화양상을 파악하고자 하였다. sucrose가 탄소원으로 사용되었을 때 3.43 mol H2/mol hexose의 최적 수소 생산량을 보였으며, 발효산물인 유기산은 acetic acid와 butyric acid가 주로 생성되었다. 카드뮴과 구리가 배양액에 존재함에 따라 수소생산량이 낮아지는 경향을 보인 반면, 유기산 중에서 acetic acid의 생성이 높아지는 경향을 나타내었으며 수소생산에 미치는 영향은 구리가 더 큰 것으로 나타났다.

• 한국식품영양학회지
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• 제23권1호
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• pp.70-75
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• 2010

본 연구는 한국의 누룩에서 분리한 Rhizopus sp. ZB9로서 탁주 및 약주 양조에 필요한 쌀 입국을 제조할 때에 배양 온도, 배양 시간, 증미 수분 함량, 입국 두께, 교반 작업 등의 배양 조건이 입국의 유기산 생성에 미치는 영향을 알기 위한 것이다. Rhizopus sp. ZB9를 접종하여 배양 조건을 달리하여서 쌀 입국을 제조하고, 각 입국의 산도를 측정하였다. 유기산 생성에 적절한 온도범위는 $28{\sim}32^{\circ}C$이었으며, 이 온도에서 36~48시간 정도 배양하는 것이 가장 적절하였다. 증미의 수분 함량을 25%에서 60%로 높임에 따라 유기산 생산은 비례적으로 증가하였다. 입국의 두께가 두꺼워지더라도 유기산 생성에 나쁜 영향을 나타내지 않았으며, 배양 중의 교반 작업은 유기산 생성에 매우 효과적이었다.

• 한국식품과학회지
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• 제6권3호
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• pp.127-132
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• 1974

Asp. usamii shirousamii $U_2$ 균의 국식 배양에 있어서 유기산 및 당화효소생성 조건에 대하여 실험한 결과는 다음과 같다. (1) 유기산 생산은 밀가루 및 밀기울 배지의 경우 $30^{\circ}C$에서 3일간 배양시에 가장 좋았으며 당화효소력은 밀가루 배지의 경우 $35^{\circ}C$, 3일간 배양시에 가장 높았고 밀기울 배지는 $35^{\circ}C$, 2일간 배양시에 거의 최고 역가를 나타냈다. (2) 3일 배양의 경우 배지의 첨수량은 밀가루 배지에서는 60% 첨수일 때, 밀기울 배지에서는 50% 첨수일 때 유기산 생성이 가장 좋았으며 당화효소 생성은 밀가루, 밀기울의 어느 배지에서나 $90{\sim}100%$ 첨수에서 가장 좋았다. (3) 밀가루와 밀기울의 배지를 비교하여 볼 때 유기산의 생성은 밀가루 배지가 좋았으며 당화효소생성은 밀기울 배지에서 높았다. (4) 고구마 전분박과 밀가루를 동량으로 혼합했을 때 밀가루 단일배지보다 유기산 및 당화효소 생성이 높았으며 밀기울에 고구마전분박 첨가의 효과는 없었다. (5) 밀가루, 밀기울 단일배지에 비하여 고구마전분박 단일배지에서는 유기산 및 당화효소 생성이 극히 나빴다. (5) 60% 첨수의 밀가루배지에서 $30^{\circ}C$, 3일간 배양한 경우 생성유기산 중의 약 90%가 구연산이었다.

• Journal of Dairy Science and Biotechnology
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• 제40권1호
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• pp.23-34
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• 2022

In this study, to determine the importance of lactic acid bacteria (LAB) in Kombucha fermentation, biological functions, such as organic acid production and anti-inflammatory and antibacterial activities, of Kombucha, with or without LAB inoculation, were evaluated. Lactobacillus paracasei DK215, Saccharomyces cerevisiae C3, and Acetobacter pasteurianus P2 were selected as the inoculants. Organic acids were measured every 3 days from the end of fermentation using HPLC; the organic acid content of LAB-inoculated Kombucha was relatively high. Samples with or without LAB inoculation showed high antibacterial activity against Escherichia coli. The MTT assay results indicated no significant difference in concentration difference and cell death. In the NO production test, compared with the uninoculated Kombucha sample, the LAB-inoculated Kombucha sample exhibited a value similar to that of the group without LPS treatment. The levels of cytokine (IL-1α, IL-6, TNF-α) production were significantly lower than those of the LPS(+) group, indicating the anti-inflammatory activity potential of the Kombucha sample. This improvement in the biological function of the LAB-inoculated Kombucha further verifies the value of LAB in the fermented food and beverage industry.

• Journal of Animal Science and Technology
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• 제49권4호
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• pp.481-490
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• 2007

본 시험은 대조구, 항생제 처리구:Avilla- mycin?? 6ppm, MOS 처리구:MOS 250ppm, lectin 처리구:Mannosespepecific lectin 12.5ppm, Organic acid F 처리구:FORMI??(formic acid 35.4%, formate 34.6%, potassium 30.0%) 0.3%, Organic acid G처리구: GALLACID?? 0.06% 등 6처리구를 두고 이들 처리가 산란계에 미치는 영향을 비교 평가하기 위하여 생산성, 혈액성상, 혈청 IgG, 장내 미생물 균총을 조사하였다. 사양시험은 48주령의 산란계(Hy-Line Brown??) 900수를 선별하여 6처리, 5반복, 반복당 15케이지, 케이지당 2수씩 A형 2단 케이지에 수용하고 randomized block design으로 배치하였다. 6주 동안의 산란율(hen-day, hen- house egg production)에서는 MOS 처리구가 가장 높은 산란율을 보였고 모든 첨가구가 대조구보다 산란율이 높았다(P<0.05). 난중은 lectin 처리구가 가장 높았으며 모든 첨가구들이 대조구보다 높은 경향이 있었다. 연파란율은 lectin 처리구를 제외한 모든 첨가구들이 대조구보다 낮았다(P<0.05). 난황색은 Organic acid G 처리구를 제외한 모든 첨가구들이 대조구보다 높았다(P<0.05). Haugh unit는 lectin 처리구가 가장 높았으며 모든 첨가구들이 대조구보다 높았다. Leukocytes 중 SI는 lectin 처리구가 가장 높았다(P<0.05). Erythrocytes 중 RBC, HB, MCHC는 lectin 처리구가 가장 높았으며 MOS 처리구가 가장 낮았다(P<0.05). 장내 미생물에서는 처리구간에 유의적인 차이는 없었으나 Lactobacilli 수는 대조구보다 첨가구들이 높은 경향이 있었고 Cl. perfringens 수는 Organic acid F를 제외한 모든 첨가구들이 대조구보다 낮은 경향이 있었다. 혈청 IgG 농도는 MOS 처리구가 가장 높았으며 모든 첨가구들이 대조구보다 유의적으로 높았다(P<0.05). 결론적으로 본 시험에서 사용된 면역조절제(MOS, Lectin)와 유기산제는 산란계에서 항생제(Avilamycin??)와 유사한 생산성을 나타내어 항생제 대체제로서 산란계의 생산성을 효과적으로 개선 할 수 있으며 특히 이중에서 MOS의 생산성 개선효과가 가장 높았다.

• Mycobiology
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• 제48권2호
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• pp.122-132
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• 2020

Citric acid is a commercially valuable organic acid widely used in food, pharmaceutical, and beverage industries. In this study, 260 yeast strains were isolated from soil, bread, juices, and fruits wastes and preliminarily screened using bromocresol green agar plates for their ability to produce organic acids. Overall, 251 yeast isolates showed positive results, with yellow halos surrounding the colonies. Citric acid production by 20 promising isolates was evaluated using both free and immobilized cell techniques. Results showed that citric acid production by immobilized cells (30-40 g/L) was greater than that of freely suspended cells (8-19 g/L). Of the 20 isolates, two (KKU-L42 and KKU-L53) were selected for further analysis based on their citric acid production levels. Immobilized KKU-L42 cells had a higher citric acid production rate (62.5%), while immobilized KKU-L53 cells showed an ~52.2% increase in citric acid production compared with free cells. The two isolates were accurately identified by amplification and sequence analysis of the 26S rRNA gene D1/D2 domain, with GenBank-based sequence comparison confirming that isolates KKU-L42 and KKU-L53 were Candida tropicalis and Pichia kluyveri, respectively. Several factors, including fermentation period, pH, temperature, and carbon and nitrogen source, were optimized for enhanced production of citric acid by both isolates. Maximum production was achieved at fermentation period of 5 days at pH 5.0 with glucose as a carbon source by both isolates. The optimum incubation temperature for citric acid production by C. tropicalis was 32 ℃, with NH₄Cl the best nitrogen source, while maximum citric acid by P. kluyveri was observed at 27 ℃ with (NH₄)₂ SO₄ as the nitrogen source. Citric acid production was maintained for about four repeated batches over a period of 20 days. Our results suggest that apple and banana wastes are potential sources of novel yeast strains; C. tropicalis and P. kluyveri which could be used for commercial citric acid production.