• Journal of Microbiology and Biotechnology
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• 제2권4호
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• pp.293-296
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• 1992

Increased concentrations of yeast extract led to increased growth yields and faster growth rates of the newly isolated Clostridium thermobutyricum. This species produced butyrate as its main fermentation product from glucose as well as from yeast extract. In the presence of peptone or tyrptone and during growth on agar, up to 70% of the cells sporulated. Growth yields were 30 and 55 g per mole glucose in the presence of 0.05 and 2.0% yeast extract, respectively. The Arrhenius graph was biphasic, exhibiting an intermediary plateau around $38^{\circ}C$ with a concomitant change in the Arrhenius energy. The optimum temperature was $55^{\circ}C$. An unusually sharp decline in the growth rate occurred above $59^{\circ}C$ .

• 한국미생물·생명공학회지
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• 제24권5호
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• pp.540-545
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• 1996

A facultative anaerobe Enterococcus faecium 19-46-4 was used to study the production of an antimicrobial substance in anaerobic conditions. Major part of the antibiotic activity was found in the culture filtrate of the bacterium. The active compound was extracted by an equal volume of iso-butanol and concentrated in vacuo (at 50$\circ$C) before purification by C-18 liguid column chromatography and HPLC. A chromatographically pure compound was obtained by two passages of HPLC columns, The compound appeared as a pale-yellow powder. The yield was about 2.5 mg 1$^{-1}$ culture filtrate. The compound was named as KIST 194. KIST 194 were identified as cholic acid (3$\alpha$, 7$\alpha$, 12$\alpha$-trihydroxy-5$\beta$-cholan 24-oic acid) based on its physico-chemical properties determined by UV, IR, $^{1}H-NMR, $^{13}$C-NMR, El-MS and LC-MS.

• International Journal of Oral Biology
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• 제39권2호
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• pp.115-120
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• 2014

Minimal inhibitory concentration (MIC) is the lowest concentration of antibiotics that inhibits the visible growth of a microorganism. It has been reported that sub-MIC of antibiotics may result in morphological alterations along with biochemical and physiological changes in bacteria. The purpose of this study was to examine morphological changes of periodontal pathogens after treatment with sub-MIC antibiotics. Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, and Porphyromonas gingivalis were used in this study. The MIC for amoxicillin, doxycycline, metronidazole, penicillin, and tetracycline were determined by broth dilution method. The bacterial morphology was observed with bright field microscope after incubating with sub-MIC antibiotics. The length of A. actinomycetemcomitans and F. nucleatum were increased after incubation with metronidazole; penicillin and amoxicillin. P. gingivalis were increased after incubating with metronidazole and penicillin. However, F. nucleatum showed decreased length after incubation with doxycycline and tetracycline. In this study, we observed that sub-MIC antibiotics can affect the morphology of periodontal pathogens.

• 한국환경과학회지
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• 제16권11호
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• pp.1295-1300
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• 2007

The antibacterial effects of anodic electrolyzed water against various bacteria were studied in this investigation. Complete inactivation of Gram-positive and Gram-negative bacteria occurred within 15 s after exposure to anodic electrolyzed water. Moreover, 1/2, 1/5 and 1/10 diluted anodic electrolyzed water by adding deionized water showed strong antibacterial effects. However, the inhibitory effect of anodic electrolyzed water on the anaerobe of Propionibacterium acnes was much weaker than that on the aerobes, including Gram-positive and Gram-negative bacteria. The degraded fragments of E. coli cell were observed upon treating anodic electrolyzed water for 1 min by using scanning electron microscopy.

• 대한수의학회지
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• 제61권4호
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• pp.33.1-33.5
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• 2021

This study reports the detection and genotyping of the first clinical case of bovine anemia due to Theileria orientalis group (BATOG) in non-grazed dairy cow in upper South Korea. Blood and serum tests revealed anemia and hyperbilirubinemia from animal showing clinical symptoms, and later confirmed as piroplasmosis-positive. Follow-up surveillance on the herd revealed 2 asymptomatic cows with anemia. The three animals were confirmed theileriosis-positive and genotyping revealed the clinical and one of the asymptomatic cases have Chitose, while the other has Ikeda genotype. Clinical BATOG cases were rarely reported worldwide, and asymptomatic animals left untreated could serve as parasite reservoir.

• Journal of Species Research
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• 제11권2호
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• pp.108-116
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• 2022

During a field survey to report unrecorded Korean ciliates, we collected five anaerobic ciliate species in two samples from freshwater and marine environments. These species belong to the classes Armophorea and Plagiopylea. The morphology of these species was studied based on live observations, protargol impregnation, and scanning electron microscope. Brachonella contorta is characterized by a size of 80-100×40-60 ㎛ in vivo, a bullet-shaped body, and about 60 oral polykinetids making 360° spiral around long axis. Brachonella pulchra is characterized by a size of 80-110×50-70 ㎛ in vivo and adoral zone composed of about 40 oral polykinetids with minimal spiralization. Metopus setosus is characterized by a size of 45-70×20-30 ㎛ in vivo, about 22 ciliary rows, very long caudal cilia, and 20 oral polykinetids. Plagiopyla nasuta is a freshwater species characterized by a size of 80-120×50-60 ㎛ in vivo, striated band present, straight extrusomes, and about 70 somatic ciliary rows. The marine Plagiopyla frontata is characterized by a size of 80-120×40-60 ㎛ in vivo, an oval to ellipsoid body shape, 50-60 somatic ciliary rows, and curved extrusomes.

• 한국임상수의학회지
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• 제40권1호
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• pp.78-82
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• 2023

Edwardsiella (E) tarda belongs to the Enterobacteriaceae family and is a motile, gram-negative, rod-shaped, facultative anaerobe regarded as an opportunistic and food-borne pathogen in animals and humans. A 21-year-old male Eurasian brown bear (Ursus arctos arctos) died suddenly without any preliminary signs. Necropsy performed according to standard protocol revealed swollen abdomen with hemorrhagic congestions of the gastroenteric organs, ascites, and hemorrhagic exudates around the mouth. The liver showed discoloration, along with a severely swollen and multiple hemorrhages of the spleen, an elongated gallbladder, and a congested cortex and medullar lesion of kidneys. The stomach contained semi-liquid exudates and undigested chicken exuding a decayed odor. The stomach membranes were dark-gray in color with several cysts in the fundus lesions. Rod-shaped bacteria were found in the major organs by Giemsa staining, identified as E. tarda using a biochemical rapid diagnostic identification kit.

• Asian-Australasian Journal of Animal Sciences
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• 제24권12호
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• pp.1718-1728
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• 2011

Two experiments were conducted to investigate the in vitro ability of keratinase to hydrolyze soybean glycinin and ${\beta}$-conglycinin and to evaluate the in vivo effects of keratinase when included in corn-soybean diets with different levels of crude protein and fed to nursery pigs. In experiment 1, a saturated keratinase solution (1 ml) was added to two blank controls of either glycinin or ${\beta}$-conglycinin resulting in the hydrolysis of 94.74% glycinin and 88.89% ${\beta}$-conglycinin. In experiment 2, 190 pigs (8.3${\pm}$0.63 kg BW) were allotted to one of four treatments in a 2${\times}$2 factorial arrangement on the basis of body weight, and sex was balanced among the pens. The effects of crude protein (19 vs. 22%) and keratinase (0 vs. 0.05%) were studied. Each treatment was applied to six pens with seven (two pens) or eight pigs per pen. Pigs were fed the experimental diets for 21 d. Weight gain and feed conversion ratio were improved (p<0.05) with keratinase supplementation while feed intake was reduced (p<0.05). Keratinase supplementation increased (p<0.05) the apparent total tract digestibility of dry matter, energy, crude protein and phosphorus. Keratinase supplementation also increased n-butyric acid in the cecum and colon, lactobacilli and total anaerobe counts in the colon as well as the ratio of villus height to crypt depth in the ileum. Additionally, fecal score, ammonia nitrogen and branch chain volatile fatty acids in the colon, E. coli and total aerobe counts in the colon, crypt depth in the jejunum and ileum as well as serum interleukin-1 and interleukin-6 concentrations were also decreased (p<0.05) by keratinase supplementation. A reduction in dietary crude protein decreased (p<0.05) colon ammonia nitrogen concentration and cecal propionic acid and branch chain volatile fatty acid concentrations. In addition, cecal E. coli counts, colon total anaerobe counts, ileal crypt depth, and serum interleukin-1 and interleukin-6 concentrations were also decreased (p<0.05) with the reduction of dietary crude protein. With the exception of fecal scores, there were no significant interactions between crude protein and keratinase. This study provides evidence that dietary keratinase supplementation improved nursery pig performance by improving intestinal morphology and ecology, thus improving nutrient digestibility and alleviating the inflammatory response.

• 생명과학회지
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• 제28권10호
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• pp.1244-1253
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• 2018

반추위 속에는 박테리아, 고세균, 프로토조아, 곰팡이 및 바이러스와 같은 다양한 미생물들이 편성의 혐기조건에서 공생하고 있다. 사료의 발효에 중요한 역할을 하고 있는 반추위 미생물은 위내 발효과정에서 에너지 손실에 영향을 주는 메탄의 발생을 제외하면 에너지와 단백질 대사에 필수적인 다양한 휘발성 지방산을 생산한다. 반추위내 미생물의 이용효율을 개선시키기 위해 사료배합비조절, 천연사료첨가제, 생균제첨가 등의 다양한 접근방법들이 사용되고 있다. 최근에 반추위 군집에 대한 메타유전체 또는 메타전사체와 같은 차세대 유전체 해독기술 또는 차세대 시퀀싱 기술의 적용으로 반추위 미생물의 다양성 및 기능에 대한 이해가 크게 증가하였다. 특히 메타단백질체와 메타대사체는 반추위 생태계의 복잡한 미생물네트워크에 대한 더 깊은 통찰력을 제공할 뿐만 아니라, 다양한 반추가축용 사료에 대한 반응을 제공함으로서 생산효율을 개선시키는데 기여하였다. 본 논문에서는 반추위내 사료의 발효와 이용을 향상시키기 위한 메타오믹스 기술, 즉, 메타유전체, 메타전사체, 메타단백질체 및 메타대사체의 최신 응용기술을 요약하고자 한다.

• 생명과학회지
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• 제31권5호
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• pp.520-526
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• 2021

반추가축의 반추위내 미생물단백질은 단백질의 공급원중 일부이며 글루타메이트 생산을 위한 공급원이기도 하다. 글루탐산은 신체의 대사반응, 근육 및 기타 세포구성에 필요한 단백질 합성물질로 이용되며 면역기능항진에도 매우 필수적으로 이용된다. 또한 계면활성제, 완충제, 킬레이트제제, 향미 증강제, 배양배지 및 농업 분야에서 성장촉진제로 이용된다. 글루탐산은 감마-아미노부티르산(GABA)생산을 위한 기질로서 본 연구는 글루탐산의 기능과 글루탐산 탈 탄산효소 유전자를 포함하는 미생물에 대한 정보를 제공하는데 있다. GABA는 체온 조절, 건물섭취량, 유생산량 및 유성분을 개선시키는 것으로 알려져 있다. 대부분의 글루탐산과 GABA 생성 미생물은 대부분 Lactococcus, Lactobacillus, Enterococcus 및 Streptococcus 종과 같은 젖산생성 미생물로 이루어져 있다. 반추위내 대사기전을 보면 GABA 합성을 통해 succinate 생산과정을 거치고, succinate는 탈수소효소반응을 통해 프로피온산과 기타 대사산물을 생산할 수 있다. 또한 Clostridium tetanomorphum과 혐기성 Micrococci는 글루타메이트 발효과정에서 아세트산과 낙산을 생성한다. 프로피온산과 기타 대사산물은 간에서의 혈당으로 전변되어 반추가축의 유선세포에서 유당 및 체중증가를 위한 에너지를 제공한다. 이를 통해 반추가축의 건강상태 개선 및 성장촉진을 위한 중요한 미생물로 이용가능하다.