Lactobacillus plantarum의 생육 억제에 미치는 요소 및 protoplast 형성에 관한 연구

박범식,--,전억한,조재선 경희대학교 부설 식량자원개발연구소 1993 硏究論文集 Vol.14 No.-

발효중 L.plantarum의 생육 영향 실험은 다양한 인자를 이용하여 결정하였는데 당 종류 및 함량에 따른 성장 효과는 glucose가 20%일때 발효성 당 기질의 활용율이 높았으며, pH 저하 속도 역시 가장 빨랐다. 초기 pH를 6.5에서 3.0까지 acids 첨가로 고정시켜서 초기 pH에 따른 발효중 pH의 변화 정도은 접종 초기 pH와 관계없이 4.0 이하에선 pH 저하가 거의 일어나지 않았으나 세포 농도는 증가하였다. 초기 pH 40 이상에서는 급격한 pH 저하가 있었다. 따라서 acidulants 첨가시 적어도 pH를 40이하로 낮추게 되면 세포 성장이 둔화 되어 김치 발효에 앞서 acididulation을 행할 수 없게 된다. 젖산균의 종류에 따라서 일정농도 이상의 염농도에서 생육이 중지되거나 삼투압이 세포내보다 클때에는 세포가 파열하여 생육할 수 없다. 염농도 1%에서 3%까지 증가함에 따라 세포상장에 어느정도 영향을 미쳤으나 pH저하에는 거의 영향을 미치지 않았다. DEDT와 Butylated hydroxyanisol은 생장 억제제로 각 1%, 0.04% 첨가한 경우 접종초기와 배양후의 pH 변화는 거의 또는 전혀 일어나지 않았으며, Zn을 첨가하였을때도 pH 변화가 발견되지 않았다. Protoplast를 생성하기 위하여 세포벽 용균 효소로 lysozyme 40㎍/ml과 protoplast 형성율이 가장 좋은 생육 시기인 15hr으로 결정하였다. 30℃, ph75에서 현저한 흡광도 감소 경향과 protoplast 형성율도 우수하게 나타났다. 15% sucrose, 20mM MgCl₂, 6mM CaCl₂에서는 흡광도 감소 경향을 보이지 않았으나, protoplast 형성율은 다른 농도에서보다 증가하는 경향을 나타냈다. Plasma expander로 알려진 gelatm을 첨가하였을 경우에는 6660㎚에서 유의적인 흡광도 감소경향을 보이지 않았으며 단지 protoplast를 형성시키는데 있어서 중요한 보조적 역할을 수행하는 것으로 사료된다. Lactic acid bacteria involved in KimChi fermentation was tested for disposition of preservation with initial pH and inhibitory activity against Lactobacillus plantarum. The inhibotory effects of various factors which are additional sugars, lowering initial pH, addition of salts on the cell growth were evaluated by measuring capacity of acid formation. The cell growth was found to be high at 20% glucose in accordance with fast falling of pH. It was revealed that the cell growth was inhibited with some decrease in pH when concentration of salt increased up to 3%. It was also found that Zn concentrations ranging from 0.01% to 0.04% did not show any influence on the cell growth. Microorganisms of L. plantarum were also used for the protoplast fusion to obtain the improved strains for KimChi fermentation. Protoplasts of L. plantarum was produced by lysozyme digestion at 30℃ for 180min. The strain was treated with 40㎍/㎖ of lysozyme in 30 mM Tris-Cl buffer(pH 7.5) containing 10% sucrose at the late logarithmic growth. It was found that the efficiency of protplast formation was high at 30℃, pH 7.5 determined by decrease in absorbance. Optimum concentrarions of sucrose, Ca^(2+), Mg^(2+) for protoplast formation were determined to be 15%, 20 mM and 6 mM, respectively.

Spectroscopic and Electrochemical Detection of Thrombin/5'-SH or 3'-SH Aptamer Immobilized on (porous) Gold Substrates

Buem Jin Park,Young Seung Sa,Yong Hwan Kim,김영훈 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.1

Thrombin is a serine protease that catalyzes the conversion of soluble fibrinogen to insoluble fibrin, and thus induces physiological and pathological blood coagulation. Therefore, it is important to detect thrombin in blood serum for purposes of diagnosis. To achieve this goal, it has been suggested that a 15-mer aptamer strongly binds with thrombin to form a G-quartet structure of the aptamer. Generally, 5'-end thiol-functionalized aptamer has been used as an anti-thrombin binder. Herein, we evaluate the possibility of utilizing a 3'-SH aptasensor for thrombin detection using SPR spectroscopy, and compare the enhancement of the electrochemical signal of the thrombin-aptamer bound on a porous gold substrate. Although the two aptamers have similar configurations, in SPR analysis, the 3'-SH aptamer was a effective aptasensor as well as 5'-SH aptamer. Results from electrochemical analysis showed that the porous gold substrate acted as a good substrate for an aptasensor and demonstrated 5-fold enhancement of current change, as compared to gold thin film.

Residual characteristics of (E)-N¹-[(6-chloro-3-pyridyl)methyl]N²-cyano-N¹-ethylacetamidine(Acetamiprid) formulated with controlled release in water, soil and red pepper(Capsicum annum L.)

Buem-Haeng Cho,Ji-Young Lee,Won-Ki Lee,Jae-Young Lee,Yong-Man Yu 한국농약과학회 2003 한국농약과학회 학술발표대회 논문집 Vol.- No.-

이산화티타늄 광촉매를 이용한 총유기탄소 분석방법

박범근 ( Buem Keun Park ),김성미 ( Sung Mi Kim ),이영진 ( Young-jin Lee ),백종후 ( Jong-hoo Paik ),신정희 ( Jeong Hee Shin ) 한국센서학회 2021 센서학회지 Vol.30 No.5

Biochemical oxygen demand (BOD) and chemical oxygen demand (COD) methods are conventional analytical methods to analyze water quality. Both of these methods are technically indirect measurement methods, require complicated preconditions, and are timeconsuming. On the other hand, the total organic carbon (TOC) method is a direct and fast measurement method which is more intuitive and accurate than the BOD and COD methods. However, general TOC analysis methods involve complicated processes and high power consumption owing to the process of phase transition from liquid to gas by a high-temperature heater. Furthermore, periodic consumables are also required for the removal of inorganic carbon (IC). Titanium dioxide (TiO₂) is one of the most suitable photocatalysts for simple processes. Its usage involves low power consumption because it only reacts with the organic carbon (OC) without the requirement of any other reagents and extra processes. We investigated a TiO₂ photocatalyst-based TOC analysis for simple and affordable products. TiO₂-coated fiber substrate maintained under carbon included water was exposed to ultraviolet (UV) radiation of wavelength 365 nm. This method is suitable for the real-time monitoring of water pollution because of its fast reaction time. Its linear property is also sufficient to match the real value.

$^{13}C$ Spin-Lattice Relaxation Study of Segmental Motions in n-alkanes: n-Undecane and n-Dodecane

Min, Buem-Chan,Lee, Jo-Woong Korean Magnetic Resonance Society 1998 Journal of the Korean Magnetic Resonance Society Vol.2 No.1

The motions of carbon-chain backbone in n-undecance and n-dodecane dissolved in CDCl3 are investigated by 13C NMR relaxation study. For this purpose a model of C - C backbone motions for these molecules is introduced that takes into account the cooperativities between rotations about two $\beta$-coupled C - C bonds. In this model it is assumed that the major conformational interconversions occurring in the inner part of the chain involve the type II jumps only, although at terminal part of the chain both type II and type III motions are assumed to take place. Information of the rate constants of these conformational transitions could be extracted by comparing the T1's calculated on the basis of the assumed model with those observed over the temperature range of 248 - 308 K. The calculations were performed according to the method proposed by Wittebort and Szabo. The activation energies, ranging from ca 12 to 20 kJ/mol, could be obtained from the Arrhenius plots of these calculated rate constants.

고온 가압 적층 소결에 의한 황화아연 세라믹스의 광학성 특성

박범근 ( Buem-keun Park ),백종후 ( Jong-hoo Paik ) 한국센서학회 2021 센서학회지 Vol.30 No.3

During the manufacture of a ZnS lens with excellent transmittance in the mid-infrared region (3-5 μm) by the hot-press process, a single-layer sintering method is used in which one lens is manufactured in one process. Additional research is required to improve this single-layer sintering method because of its low manufacturing efficiency. To solve this problem, the variation in optical properties of ZnS lenses with change in sintering temperature was investigated by introducing a Stack sintering method that can sinter multiple lenses simultaneously. A carbon paper was placed between the molded lenses and sintered into five layers. The average permeability of 67% at medium infrared wavelengths of 3-5 μm was excellent under the following sintering conditions: pressure of 50 MPa and temperature of 850℃. This value is 1% less than the average permeability in the case of single-layer sintering of the ZnS lens. It was confirmed that the stack sintering method developed in this study can be used to manufacture a large number of lenses with excellent characteristics in a single process.

$^{13}$C NMR Study of Segmental Motions of n-Heptane in Neat Liquid

Min, Buem-Chan,Chang, Sei-Hun,Shin, Kook-Joe,Lee, Jo-Woong Korean Chemical Society 1985 Bulletin of the Korean Chemical Society Vol.6 No.6

Carbon-13 nuclear spin-lattice relaxation times have been measured over the range of temperature from 213K to 353K for carbons in n-heptane in neat liquid. The experimental data have been analyzed to obtain informations of segmental motions in the chain polymers by employing a model which describes jumps between several discrete states with different lifetimes. The overall reorientation of the molecule is assumed to be isotropic rotational diffusion. From the above analysis the activation energies of each C-C bond reorientation as well as the overall reorientation have been obtained through the Arrhenius-type temperature dependence.

Effect of Mature Miscanthus sacchariflorus var. No. 1 on In Vitro Rumen Fermentation Characteristics and Its Dry Matter Digestibility

Sang Buem Cho(조상범),David Tinotenda Mbiriri,Sung Jin Oh(오성진),A Reum Lee(이아름),Jin Ho Yang(양진호),Chae Hwa Ryu(유채화),Chang Min Park(박창민),Yun Ho Moon(문윤호),Jung-Il Chae(채정일),Nag-Jin Choi(최낙진) 한국초지조사료학회 2012 한국초지조사료학회지 Vol.32 No.2

본 연구는 반추동물의 조사료 자원으로서 거대억새를 개발하기 위한 목적으로 수행되었다. 우리나라에서 새롭게 개발된 품종인 거대억새 1호를 완숙기 이후에 채취하여 in vitro 반추위 발효를 이용해 반추위내 pH, 암모니아태 질소, 가스발생량, 휘발성 지방산 생성량 및 건물소화율을 조사하였으며, 볏짚과 비교하여 평가하였다. 거대억새는 볏짚에 비하여 유의적으로 높은 반추위내 pH를 나타내었다 (p<0.01). 암모니아태 질소의 경우 배양 12시간 이후에는 두 처리구간의 유의적인 차이를 나타내지 않았다 (p>0.05). 배양 6시간 이후 부터는 거대억새의 가스발생량이 볏짚에 비하여 유의적으로 낮게 나타났다 (p<0.05). 휘발성 지방산 생성량에 있어 acetate, propionate, butyrate, valerate 및 총생상량에서 볏짚이 거대억새보다 높게 나타났다. 그러나 iso-butyrate와 iso-valerate에서는 두 조사료원별 차이는 발견되지 않았다. 건물소화율에 있어 배양 12~24시간 사이의 거대억새 소화율이 볏짚에 비하여 유의적으로 나타났다. 결론적으로 거대억새의 이용성은 볏짚의 약 80% 수준인 것으로 나타났다. This study was conducted to develop Miscanthus as a new roughage resource for ruminant animals. Miscanthus sacchariflorus var. No 1, a newly developed germtype in Korea, was harvested at late maturity stage and its effect on rumen pH, ammonia nitrogen, gas production, volatile fatty acid (VFA) production and digestibility were evaluated using in vitro rumen fermentation. The effects of Miscanthus were compared with rice straw. Miscanthus showed significantly higher pH compared to rice straw (p<0.01). As for ammonia nitrogen, there was no significant difference after 12 h of incubation (p>0.05). Gas production in Miscanthus was significantly lower than that of rice straw in overall incubation time (p<0.05) after 6 h of incubation. In VFA production, acetate, propionate, butyrate, valerate and total VFA production in Miscanthus were lower than those in rice straw. However, production of iso-butyrate and isovalerate were not different in between two forage materials. Dry matter digestibility of Miscanthus was significantly lower than rice straw (p<0.05) during 12~24 h of incubation. As a result, the availability of Miscanthus as roughage source showed approximately 80% that of rice straw.

캔틸레버형 모듈을 이용한 광대역 압전 하베스터 개발 및 평가

박범근 ( Buem-keun Park ),백종후 ( Jong-hoo Paik ) 한국센서학회 2020 센서학회지 Vol.29 No.4

In cantilever type piezoelectric energy harvester, the amount of power generation decreases rapidly when outside a certain frequency. The thickness and weight of the cantilever metal plate were modified to develop cantilevers that could produce high power over a wide frequency range. The thicker the cantilever, the higher the power in the higher frequency range. As the weight of the mass increased, the cantilever tended to generate higher power, and the frequency band decreased. A 0.6 mm metal plate cantilever that had a mass of 3.3 g generated power that exceeded 3 mW within the 91-102 Hz range, with average and output values of 9.484 mW and 20.748 mW, respectively, at 99 Hz.

영상 내의 신체 핵심 좌표 데이터를 활용한 머신러닝 기반 수어 인식 연구

김범준(Buem-Jun Kim),전형기(Hyeong-Gi Jeon),이경희(Kyoung-Hee Lee) 한국정보통신학회 2023 한국정보통신학회논문지 Vol.27 No.4

본 논문에서는 실시간 영상 내의 신체 움직임을 머신러닝 기반으로 추론하여 수어를 인식하는 시스템을 제안한다. 제안 시스템은 움직이는 신체부위의 핵심 좌표 데이터로 구성되는 모션 벡터를 머신러닝에 활용함으로써 인공신경망 모델의 훈련 시간을 줄이고 동작 인식의 정확도를 높이는 특징을 갖는다. 이러한 모션 벡터는 표현 시간이 상이한 다양한 낱말들에 대해 동일한 규격으로 구성되므로 추론의 신뢰도를 더욱 높이는 효과를 제공한다. 그리고 수어문장을 표현한 영상 중 각 낱말에 해당되는 부분 영상을 정확하게 분할해 내기 위해 점진적으로 추론 구간을 조정하면서 반복적인 신뢰도 평가를 수행하는 방법을 제시한다. 실험을 통해 영상 자체를 학습 및 추론에 이용하는 일반적인 기존 방식과 비교했을 때 훈련 시간, 추론 속도 및 신뢰도, 부분 영상의 분할 정확도 측면에서 제안 시스템이 더욱 우수한 성능을 보임을 알 수 있었다. This paper proposes a sign language recognition system based on machine learning, which can infer the meaning of body movement in realtime video. It has a feature that motion vectors constructed with keypoint data of moving body are used for machine learning. This enables the proposed system to reduce the training time of an artificial neural network model and to enhance the recognition accuracy. Since those motion vectors have the same size and format regardless of the different expression times of words, the confidence level of an inference could be further increased. To correctly divide a part of video corresponding to each word in a sentence, we propose an iterative evaluation method of confidence levels for inferences with the gradual length adjustment of video fragment. The experimental results showed that our system outperforms a conventional method using the video itself for training and inference, in training time, inference speed, confidence level of inference and accuracy of video fragmentation.