• 한국식품과학회지
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• 제7권4호
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• pp.238-242
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• 1975

Aspergillus usamii shirousamii $U_2$ 균(菌)의 극식배양에 의한 유기산 및 당화효소생성에 미치는 영향에 대하여 실험한 결과는 다음과 같다. 1) 공시항균제(供試抗菌劑)중 일정한 농도(濃度)의 nitrofurazone과 $AF_2$의 첨가(添加)에 의하여 유기산과 당화효소(糖化酵素)의 생성이 촉진되었다. 2) 유기산의 생성은 밀가루에 $AF_2$ 10ppm 용액을 50% 첨수(添水)한 배지에서 가장 좋았다. 3) 당화효소(糖化酵素)의 생성은 밀기울에 nitrofurazone $100{\sim}500ppm$ 용액을 100% 첨수(添水)한 배지에서 가장 양호하였다.

• 생명과학회지
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• 제22권10호
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• pp.1324-1329
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• 2012

본 연구의 목적은 organic acids를 첨가하여 in vitro 상의 반추위 발효성상과 반추위 내 메탄 억제에 미치는 영향에 대한 효과를 알아보고자 하였다. 반추위액은 순천대학교 부속목장의 반추위 cannula가 시술된 Holstein에서 채취하였고, organic acids는 반추위액과 버퍼의 혼합액에 첨가하여 배양하였다. 그 결과 pH 값은 lactic acid, malic acid 및 succinic acid첨가구에서 6.69에서 6.16 정도로, 대조구와 다른 첨가구보다 낮았다. 총 가스 발생량은 배양 48시간에 aspartic acid, malic acid 및 succinic acid첨가구에서 유의적(p<0.05)으로 높았고, 메탄 발생량은 lactic acid 첨가구에서 대조구보다 낮았다. 총 VFA와 propionic acid의 농도는 배양 12시간에 모든 첨가구가 대조구에 비해 높았다. 반추위 미생물 측정 결과에서는 Fumaric acid와 malic acid의 bacteria수가 대조구에 비해 유의적으로 증가하였으며(p<0.05), protozoa수는 유의적(p<0.05)으로 감소되었다. 이상의 실험 결과를 종합해 보면, organic acids의 첨가는 반추위 내 pH를 감소시키고 가스 발생량, 반추위 미생물 성장량 및 propionic acid 모두 증가시켰으며, 특히 lactic acid는 메탄생성을 억제하였다. 앞으로 Organic acid와 다른 메탄억제 물질과 혼합하여 반추위 내 메탄생성 억제에 관한 구체적인 연구가 필요한 것으로 사료된다.

• Journal of Microbiology and Biotechnology
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• 제25권1호
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• pp.81-88
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• 2015

This study describes a novel strategy to regulate the metabolic flux for lactic acid production in Lactobacillus casei. The ldhL gene encoding _L-lactate dehydrogenase (L-LDH) was overexpressed in L. casei, and a two-stage oxygen supply strategy (TOS) that maintained a medium oxygen supply level during the early fermentation phase, and a low oxygen supply level in the later phase was carried out. As a consequence, a maximum L-LDH activity of 95.6 U/ml was obtained in the recombinant strain, which was over 4-fold higher than that of the initial strain. Under the TOS for L. casei (pMG-ldhL), the maximum lactic acid concentration of 159.6 g/l was obtained in 36 h, corresponding to a 62.8% increase. The results presented here provide a novel way to regulate the metabolic flux of L. casei for lactic acid production in different fermentation stages, which is available to enhance organic acid production in other strains.

• 한국식품영양과학회지
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• 제24권2호
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• pp.254-260
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• 1995

Yogurt base were prepared from milk added with skim milk powder or Aloe vera powder and femented with lactic acid bacteria(the single or mixed strain of Lactobacillus bulgaricus and Streptococcus thermophilus). The yogurt product were evaluated for acid production(pH, titratable acidity), number of viable cell, viscosity, sensory property and quality-keeping property. The composition of organic acid were also analyzed by HPLC. Addition of Aloe vera remarkably accelerated acid production, and titratable acidity of Aloe vera yogurts(1.293∼1.407%) after 24 hours incubation was higher than that of yogurts added with only skim milk powder(9.98∼1.110%). Yogurt fermented with the mixed strain of L. bulgaricus and Sc. thermophilus was more acidic than that of single strains. The propagation of lactic acid bacteria was stimulated by Aloe vera and the number of viable cell after 24 hours incubation were above 9.87log CFU/ml. Viscosity of Aloe vera yogurt(3,860∼4,300CPS) was higher than that of yogurt with only skim milk powder(2,402∼2,604CPS). The overall sensory score of Aloe vera yogurt femented by mixed strain was the best of tested yogurt. When yogurt with Aloe vera was kept at 5℃ for 15 day, it's quality-keeping property was relatively good. The major organic acid of Aloe vera yogurt was lactic acid and lactic acid content of yogurt increased by addition of Aloe vera powder. The citric acid content decreased wtih fermentation and malonic acid, pyroglutaric acid and α-ketoglutaric acid were analyzed out a little.

• Asian-Australasian Journal of Animal Sciences
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• 제33권2호
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• pp.245-253
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• 2020

Objective: To develop the fermentation quality and chemical composition of alfalfa (Medicago sativa Lam.) silage, plants were inoculated with different lactic acid bacteria (LAB) strains at field 24 hours before harvest. Methods: The treatment groups were as follow: silage without additive as a control and inoculated with each strains of Lactobacillus brevis (LS-55-2-2), Leuconostoc citerum (L. citerum; L-70-6-1), Lactobacillus bifermentans (L. bifermentans; LS-65-2-1), Lactobacillus plantarum (L. plantarum; LS-3-3) and L. plantarum (LS-72-2). All the silages were stored at 25℃. Parameters such as pH, microorganism and volatile fatty acid contents, crude protein, neutral detergent fiber, acid detergent fiber, net gas, metabolizable energy, organic matter digestibility, dry matter intake and relative feed value were measured to determine fermentation quality, chemical compositions and relative feed value of alfalfa silages. Results: Significant differences were found among the control and treated groups in terms of pH and microorganism contents at all opening times and crude protein, net gas, metabolizable energy and organic matter digestibility of final silage. The pH values ranged from 4.70 to 5.52 for all treatments and control silage had the highest value of overall treatments at T₇₅d silages. Volatile fatty acid of silages was not influenced significantly by inoculations. However, lactic acid content of L. bifermentans (LS-65-2-1) was higher than the other treatments. The highest metabolizable energy and organic matter digestibility were recorded from L. citerum (L-70-6-1) inoculation. In addition, no significant differences were found among treatments in terms of neutral detergent fiber, acid detergent fiber, dry matter intake and relative feed value. Conclusion: Among the treated LAB isolates, L. bifermentans came into prominence especially in terms of organic acid composition and quality characters of silages.

• 유기물자원화
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• 제27권4호
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• pp.71-81
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• 2019

본 연구는 비료자원으로 이용 가능한 국내 부존자원인 농업부산물의 활용성 제고를 위해 발생량을 추정하고, 주요 비료 성분 (질소, 인산, 칼리) 함량을 선행연구 및 자료들을 수집하여 향후 수입 유박 대체를 위한 국내 자원 발굴 및 활용에 관한 기초자료로 활용하고자 하였다. 2018년 농작물 생산량과 환산계수를 활용하여 주요 34종의 농작물 부산물의 연간 발생량을 추정하였다. 전체 농업부산물 중 볏짚이 50.3%로 가장 많이 발생하였으며 그 다음 왕겨가 8.7%로 벼 재배 후 발생되는 부산물이 전체 59.0%로 대부분을 차지하였다. 또한 농촌지역에서 발생되는 부산물 40종에 대한 비료 성분 (질소, 인산, 칼리)의 함량을 목록화 하였으며, 농업부산물의 질소, 인산, 칼리 성분의 평균 함량은 각 1.43%, 0.59%, 1.90%로 나타났다. 2018년 기준 26종의 농업부산물의 연간 질소공급 잠재량을 추정한 결과 44,911톤의 질소를 공급할 수 있는 것으로 조사되었다. 조사된 농업부산물들은 질소, 인산, 칼리 등 비료 성분을 함유하고 있으나 유기질 비료의 주원료로 사용되는 아주까리 유박의 비료 성분 함량에 비해 대체적으로 낮게 나타났다. 농업부산물은 발생하는 시기나 장소, 양분 함량이 매우 다양하기 때문에 이를 효율적으로 활용하기 위한 관리방안 수립이 필요하며 국내 농업부산물을 활용한 비료 및 퇴비 연구를 통하여 수입 유박을 대체하는 자재 개발 및 보급이 요구된다.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.2
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• pp.323-323
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• 2006

• Asian-Australasian Journal of Animal Sciences
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• 제20권4호
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• pp.517-522
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• 2007

The aim of this study was to compare in vitro gas production kinetics, metabolizable energy (ME), organic matter digestibility (OMD) and microbial protein (MP) production of widely used legume hays in ruminant nutrition in Turkey. Gas production were determined at 0, 3, 6, 12, 24, 48, 72 and 96 h and their kinetics were described using the equation p = a+b ($1-e^{-ct}$). There were significant differences among legume hays in terms of chemical composition. The crude protein content of legume hays ranged from 11.7 to 18.6% of dry matter (DM); crude fat from 2.1 to 3.5% DM; neutral detergent fiber from 35.6 to 52.0% DM; acid detergent fiber from 32.0 to 35.5% DM and acid detergent lignin 1.7 to 11.0% DM. Total gas production after 96 h incubation ranged between 61.67 and 76.00 ml/0.200 g of substrate. At 24, 72 and 96 h incubation the total gas production for common vetch were significantly (p<0.01) higher than those of the other legume hays. The ME, OMD and MP of legume hays ranged from 9.09 to 11.12 MJ/kg DM, 61.30 to 75.54% and 90.35 to 138.05 g/kg DM, respectively. The ME, OMD and MP of common vetch was significantly (p<0.01) higher than those of the other hays due to low cell-wall contents and high crude protein. At the end of the experiment, differences in chemical composition of legume hays resulted in the differences in the in vitro gas production, gas production kinetics and the estimated parameters such as ME, OMD and MP. Common vetch can be recommended to hay producers and ruminant breeders, due to high ME, OMD and MP production.

• Restorative Dentistry and Endodontics
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• 제22권2호
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• pp.801-808
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• 1997

In order to develop natural anticariogenic agents, we investigated inhibitory effects of Areca catechu L. extracts on the acid production of Streptococcus mutans JC-2 and its cytotoxicity on NIH 3T3 fibroblasts were also examined. The results are as follows : 1. Major organic acid produced by Streptococcus mutans JC-2 were lactic acid and acetic acid, and their productions were decreased by additions of Areca catechu L. extracts. 2. Areca catechu L. extracts were showed noncytotoxicity on NIH 3T3 fibroblasts.

• Journal of Microbiology and Biotechnology
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• 제9권2호
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• pp.191-195
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• 1999

Bioconversion of fumarate to succinate by Enterococcus sp. RKY1 was enhanced when Tween surfactant, organic solvent, and vegetable oil were added to the fermentation medium. The maximum amount of succinate produced was 80.4 g/l after a 24 h incubation when Tween 80 was added to the culture to a final concentration of 0.1 g/l. Triton X-l00 was observed to damage the enzymes and inhibit the formation of succinate. The addition of 10 ml/l acetone increased the production of succinate by 110%. Vegetable oils used were found to be effective for succinate production as well as for the cell growth. Similar productivity increases were obtained with corn oil and Tween 80 plus biotin with the total productivity being 3.6 g/l/h, and 3.5 g/l/h, respectively, which was approximately 25% greater than that of the control. Therefore, these results indicate that com oil can be considered the most appropriate agent for the production of succinate where succinic acid was primarily used in the production of food, medicine, and cosmetics.