• 한국미생물·생명공학회지
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• 제16권2호
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• pp.156-162
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• 1988

섬유소 분해효소를 생산하는 P. verruculosum F-3 의 세포융합에 관한 연구의 일환으로 균사체로부터의 원형질체 형성과 재생 최적조건을 검토하였다. 세포벽 분해효소로 유효한 각종시판효소제제중 0.5%(w/v) Novozym 234가 가장 효과적이었고 PDY 배지로 3$0^{\circ}C$ 20시간 배양한 균사체 400mg을 3$0^{\circ}C$ 1시간 반응시 가장 많은 원형질체가 형성되었다. 원형질체 형성을 위한 최적 삼투압 조절제는 0.7M sorbitol(pH5.6)이었고 원형질체 재생을 위한 최적 삼투압 조절제는 0.6M MgSO$_4$(pH 5.6)이었으며 RCM에서의 재생율은 4.6~27.8%였다. 원형질체를 RLM에 배양시 균사체로 환원되는 형태적 변화가 관찰되었다.

• Journal of Microbiology and Biotechnology
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• 제18권11호
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• pp.1741-1746
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• 2008

This study was conducted to select endophytic actinomycetes as biocontrol agents against Chinese cabbage clubroot caused by Plasmodiophora brassicae. A total of 81 endophytic actinomycetes were isolated from surface-sterilized roots of Chinese cabbage that was grown on paddy field and upland soils collected from various locations in Korea. By using 16S ribosomal DNA (rDNA) gene sequencing, they were classified to 8 actinobacterial genera. The genus Microbispora (67%) was most frequently isolated, followed by Streptomyces (12%) and Micromonospora (11%). Three of the 81 isolates, when inoculated in germinated Chinese cabbage seeds and then transplanted to pots, effectively suppressed the occurrence of a post-inoculated strain of P. brassicae in the pots. They showed control values of 58% for strain A004, 33% for strain A011, and 42% for strain A018. Based on cell wall components, morphological characteristics, and phylogenetic analyses, the three antagonistic isolates were identified as Microbispora rosea subsp. rosea (A004 and A011) and Streptomyces olivochromogenes (A018). Further researches on the field efficacy and action modes of the three actinomycetes are in progress.

• Applied Biological Chemistry
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• 제43권3호
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• pp.169-173
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• 2000

저온에서 높은 세척력을 갖는 호소세제의 개발을 위하여 토양으로부터 alkaline protease의 활성이 높은 균주를 분리, 동정하였으며, 호소의 성질을 조사하였다. 분리균주의 형태적 특징은 Gram 음성균 이고, 간균$(0.6{\sim}0.7{\times}1.3{\sim}2.6\;{\mu}m\;in\;size)$ 형태를 하고 있으며, 운동성을 보였다. 또한 catalase 양성, aesculin, gelatin 및 casein 분해능이 있었다. 분리균주의 세포벽 구성 성분은 meso-DAP를 함유하였으며, G+C mol 함량은 43.3%를 나타내었다. 이러한 형태적, 생리 생화학적 특성의 결과로부터 분리 균주는 Acinetobacter 속으로 동정되었다. 분리 균주를 이용한 alkaline protease의 생산은 초기 pH 10과 $40^{\circ}C$에서 36시간 배양하였을 때 3,300 D.U/mL로 최대 효소 활성을 보였으며, 최적 pH와 온도는 9와 $60^{\circ}C$이었다. 또한 본 균주에 의해 생산된 alkaline protease는 두개의 활성 band를 나타내었다.

• 한국지진공학회논문집
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• 제26권1호
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• pp.13-22
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• 2022

This study proposes a low-cycle fatigue life derived from measurement points on pipe elbows, which are components that are vulnerable to seismic load in the interface piping systems of nuclear power plants that use seismic isolation systems. In order to quantitatively define limit states regarding leakage, i.e., actual failure caused by low-cycle fatigue, in-plane cyclic loading tests were performed using a sine wave of constant amplitude. The test specimens consisted of SCH40 6-inch carbon steel pipe elbows and straight pipes, and an image processing method was used to measure the nonlinear behavior of the test specimens. The leakage lines caused by low-cycle fatigue and the low-cycle fatigue curves were compared and analyzed using the relationship between the relative deformation angles, which were measured based on each of the measurement points on the straight pipe, and the moment, which was measured at the center of the pipe elbow. Damage indices based on the combination of ductility and dissipation energy at each measurement point were used to quantitatively express the time at which leakage occurs due to through-wall cracking in the pipe elbow.

• Journal of Microbiology and Biotechnology
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• 제33권7호
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• pp.895-908
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• 2023

Disposal of waste containing heavy metals into the environment is a major threat to human health and can result in toxic or chronic poisoning in aquatic life. In the current study, metal-resistant Raoultella ornithinolytica was isolated from metal-contaminated samples collected from the Tanjaro River, located southwest of Sulaymaniyah, Iraq. R. ornithinolytica was identified by partial amplification of 16S rRNA. The uptake potency of heavy metals was assessed using inductively coupled plasma-optical emission spectroscopy (ICP-OES) and indicated that R. ornithinolytica removed 67, 89, 63.4, 55.6, 56.5, 65, and 61.9% of Cd, Pb, Cr, Ni, Zn, Co, and Fe, respectively. These removal rates were influenced by temperature, pH, and contact time; at 35℃ and pH 5 with a change in the incubation time, the reduction rate improved from 89 to 95% for Pb, from 36.4 to 45% for Cu, and from 55.6 to 64% for Ni. Gene analysis indicated that R. ornithinolytica contained pbrT, chrB, nccA, iroN, and czcA genes, but the pcoD gene was absent. Energy-dispersive X-ray spectroscopy (EDS) images showed evidence of metal ion binding on the cell wall surface with different rates of binding. Transmission electron microscopy (TEM) detected different mechanisms for metal particle localization; cell surface adsorption was the main mechanism for Pb, Zn, and Co uptake, while Cd, Ni, and Fe were accumulated inside the cell. The current study describes, for the first time, the isolation of R. ornithinolytica from metal-contaminated water, which can be used as an eco-friendly biological expedient for the remediation and detoxification of metals from contaminated environments.

• Asian-Australasian Journal of Animal Sciences
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• 제29권6호
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• pp.879-886
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• 2016

As is in all economic activities, the highest yield per unit area is the main goal in animal production, while addressing the temperamental needs of animals often is ignored. Animal welfare is not only an ethical fact; it also has an economic value. Spatial environmental enrichment contributes positively to animal welfare by addressing their behavioral and mental requirements. The present study was conducted to determine the effects of weaning and spatial environmental arrangements on behaviors of goat-kids. Experimental groups were arranged in structured and unstructured spatial environments. Roughage feeder, semi-automatic concentrate feeder, bunk, bridge, and wood block were placed in the structured environment. No equipment was placed in the unstructured environment and paddock sides were enclosed with an iron sheet to prevent bipedal stance and to provide environmental isolation. In the study 10 male and 10 female Turkish Saanen goat kids were used in each group. Spatial environmental arrangements did not have significant impacts on the growth performance of kids (p>0.05). All objects in the structured group were accepted by the kids. Average use ratios of roughage feeder, semi-automatic concentrate feeder, bunk, bridge and wood block were observed as 19.3%, 14.0%, 12.6%, 3.8%, and 0.7%, respectively. There were significant differences between before- and after-weaning in use of all objects except for underneath bridge ($p{\leq}0.05$). Concentrate feed consumption, locomotion, and resting behaviors in kids showed significant differences by structural group and growth period. Roughage consumption was similar between groups, while it differed by growth period ($p{\leq}0.05$). Interaction frequency was significantly higher in structured group (p = 0.0023). Playing behavior significantly differentiated based on the growth period rather than on groups ($p{\leq}0.05$). Playing behavior significantly decreased after weaning. Abnormal oral activity was significantly higher in the structured group before weaning ($p{\leq}0.05$). Despite there being no installations facilitating climbing and bipedal stance, the kids of the unstructured group were able to exhibit 1/3 as much bipedal stance behavior as the kids of the structured group through leaning over slippery paddock wall or over their groupmates. Bipedal stance behavior of unstructured group was similar before and after weaning, while bipedal stance behavior before weaning was about 2 times that of after weaning in structured group. It was concluded that unstructured environmental arrangement limited the behavior repertoire of the goat kids.

• Asian-Australasian Journal of Animal Sciences
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• 제33권6호
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• pp.1002-1011
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• 2020

Objective: This study was conducted to determine the composition and diversity of the fungal flora at various control points in cheese ripening rooms of 10 dairy farms from six different provinces in the Republic of Korea. Methods: Floor, wall, cheese board, room air, cheese rind and core were sampled from cheese ripening rooms of ten different dairy farms. The molds were enumerated using YM petrifilm, while isolation was done on yeast extract glucose chloramphenicol agar plates. Morphologically distinct isolates were identified using sequencing of internal transcribed spacer region. Results: The fungal counts in 8 out of 10 dairy farms were out of acceptable range, as per hazard analysis critical control point regulation. A total of 986 fungal isolates identified and assigned to the phyla Ascomycota (14 genera) and Basidiomycota (3 genera). Of these Penicillium, Aspergillus, and Cladosporium were the most diverse and predominant. The cheese ripening rooms was overrepresented in 9 farms by Penicillium (76%), while Aspergillus in a single farm. Among 39 species, the prominent members were Penicillium commune, P. oxalicum, P. echinulatum, and Aspergillus versicolor. Most of the mold species detected on surfaces were the same found in the indoor air of cheese ripening rooms. Conclusion: The environment of cheese ripening rooms persuades a favourable niche for mold growth. The fungal diversity in the dairy farms were greatly influenced by several factors (exterior atmosphere, working personnel etc.,) and their proportion varied from one to another. Proper management of hygienic and production practices and air filtration system would be effective to eradicate contamination in cheese processing industries.

• 한국미생물·생명공학회지
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• 제33권4호
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• pp.295-301
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• 2005

한국 전통 젓갈로부터 항균성 lipopeptide를 생산하는 JKK238 균주를 분리하여 16S rDNA및 세포벽의 지방산 조성 분석 등에 따라 Bacillus subtilis로 동정하였다. JKK238 균주를 3일간 배양한 TSB 액체배지의 $25\%$ ammonium sulfate 침전물이 대부분의 lipopeptide를 포함하고 이들이 다양한 식물병원성 곰팡이나 세균의 성장을 강력히 저해함을 알 수 있었다. 또한 FPLC에 의해 분리 및 정제된 각 lipopeptide의 Maldi-tof분석에서, 이 균주가 iturin A, fengycin, surfactin과 같은 세 종류의 lipopeptide의 isomer들을 동시에 생산하는 균주임을 밝혔다.

• 한국버섯학회지
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• 제13권3호
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• pp.270-273
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• 2015

만가닥버섯은 일본에서 가장 중요한 식용버섯이다. 그러나 배양기간이 약 85~120일로 길어서 국내에서 다른 버섯에 비해 배양이 어려운 실정이다. 이 연구에서는 만가닥버섯 표준유전체 염기서열분석을 위하여 '해미'품종으로부터 원형질체를 분리하고 재생하여 모균주의 단핵균주를 얻었다. MCM배지 및 MYG배지에서 배양되고, 균질화된 균사체는 원형질체를 얻기 위하여 Novozyme효소를 처리하였다. 원형질체 분리의 가장 높은 효율은 MCM 배지에서 이차배양이 3일된 균사체에 2.5시간 효소처리 조건이었다. 분리된 원형질체는 재생배지에서 2주 동안 배양되어 재생되었다. 재생체는 클램프로 단핵균주를 확인하고 '해미'의 모균주의 단핵균주와 클램프 유무로 친화성을 확인하였다. 분리된 모균주의 단핵균주는 짧은 배양기간을 가진 품종을 개발하기 위한 유전적 기초자료를 완성하는 표준유전체 염기분석 재료로서 사용될 예정이다.

• 식물조직배양학회지
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• 제28권3호
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• pp.141-146
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• 2001

고추 C. anuumm, C. bacatuum, C chacoense의 하배축, 자엽 및 본엽을 원형질체 분리재료로 하여 실험한 결과, 원형질체 분리를 위해서 세포벽 분해효소로 1% Cellulysin과 0.25% Macerozyme 효소의 조합과 삼투조절제로 0.65 M sorbitol을 사용하였다. 항산화제인 MES를 효소용액에 첨가하여 줌으로써 원형질체 분리과정에서 발생하는 갈변을 억제시킬 수 있었다. 원형질체를 수정된 K8p 배지에 1∼5 mg/L zeatin, 0.5 mg/L IAA, 0.1∼0.5 mg/L TDZ, 1 mg/L 2,4-D를 첨가하여 배양하였을 때 5일에 분열을 시작하였으며 원형질체에서 얻어진 colony들을 agarose가 첨가된 반고체 배지에 고정하여 배양하는 방법이 액체평판배양 방법보다 더 효과적이었으며 이 방법은 세포배양시 분비되는 페놀류 물질로 인한 갈변을 방지할 수 있었다. 세 가지 다른 고추속의 원형질체 배양에서 얻어진 4000여 개의 캘러스를 식물생장조절제인 TDZ, IAA, 2ip, BAP, NAA, zeatin을 이용한 100가지 다양한 조합의 재분화 배지에 옮겼으나 캘러스가 커지거나 고사하는 현상만 관찰되었을 뿐 줄기로 재분화된 식물체는 얻을 수 없었다.