• Mycobiology
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• 제31권4호
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• pp.226-228
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• 2003

The multiple correlation coefficient between the values determined by dry weight and those determined by fluorometer was observed with r=0.96 and the standard error of calibration was 0.034. Using the best calibration data, in order to reconfirm the reliability of the fluorometer results in comparison with those obtained by dry weight on the cell concentration, fedbatch cultures were carried out. The results obtained by fluorometer measurements were in good agreement with those obtained by dry weight. The on-line monitoring of cell concentration by the fermentor system linked to a computer equipped with fluorometer was successfully carried out.

• 한국환경보건학회지
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• 제34권6호
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• pp.423-432
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• 2008

In this study, we investigated the possibility of auto control and the proper operating factors in the BNR(Biological Nutrient Removal) process using an NADH(Reduced Nicotinamide Adenine Dinucleotide) fluorometer, which characterized the emitted fluorescence when activated by flashes of UV light at 460 nm. In terms of finding adequate operating parameters, results indicted that nitrification efficiency decreased in the controlled DO while denitrification efficiency decreased in the controlled pH. The above results indicated that controlled operating condition after combination with NADH, DO and pH was resonable. Result obtained from the correlation between NADH and pH showed that variation trend of influent loading was similar to those of NADH and pH, and also the variation cycle was repeated on a daily basis. Consequently, this result showed the increase of BOD loading caused the nitrification efficiency to decrease because air-flow, required for nitrification, was reduced, and so the NADH value was increased. From these results, it is possible to use NADH flourimetry to assess the variation of organic load and nitrification efficiency in the case of small change in influent pH such as in sewage and also to handle and operate the load variation in the auto control system using the NADH fluorometer.

• 한국수산과학회지
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• 제41권1호
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• pp.54-60
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• 2008

High- and multi-frequency acoustic systems can measure a zooplankton patch successively and estimate the spatial distribution and abundance of zooplankton according to size using a multi-frequency inversion (MFI) method. This study measured zooplankton distribution to a depth of 150m using a multi-frequency acoustic system (TAPS-6), installed on a CTD system with a fluorometer and analyzed it using the MFI method. Simultaneously, zooplankton samples were collected by north pacific standard (NORPAC) net to confirm the species composition. The results showed that the combined method is valuable for estimating the zooplankton profile in detail and investigating the relationship between the zooplankton and phytoplankton profiles.

• Journal of the Optical Society of Korea
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• 제17권1호
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• pp.81-85
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• 2013

A miniaturized fluorescence detection system based on total internal reflection (TIR) configuration, which is applicable to detecting the presence of biological materials labeled with fluorescence dye in micro total analysis systems (${\mu}TAS$), is proposed. In conventional fluorescence testing and analysis devices, interference between the excitation light beam and the emitted light from dyes is unavoidable. This paper presents a fluorescence detection system based on TIR configuration that allows the excitation light beam and the emitted light to be spatially perpendicular to each other so as to minimize the interference where fluorescence emission is detected at the orthogonal angle to the excitation beam. We achieved the limit of detection of about 5 nmol/L with a high linearity of 0.994 over a wide range of 6-FAM mol concentration, being comparable to that in earlier studies.

• 한국지하수토양환경학회지:지하수토양환경
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• 제23권4호
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• pp.42-47
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• 2018

E. coli TG1 pBS TOM Green was cultured to produce toluene-o-monooxygenase (TOM). A biosensor system was successfully constructed using purified TOM to effectively detect trichloroethene (TCE) and tetrachloroethene (PCE), which represent some of the major contaminants in groundwater and soil. In order to utilize TOM as a sensor, NADH, a biological oxidizer, was replaced with hydrogen peroxide which is a chemical oxidizing agent. A three-layered sandwich-type sensing tip was fabricated on the outside of the hydrophilic polyvinylidene fluoride membrane. TCE and PCE were applied to the sensor and the hydrogen ions were measured by a fiber optic fluorometer using fluoresceinamine. Calibration curves were obtained for TCE and PCE in the concentration range of 0.2-100 mg/l, and the detection limit of the system was $10{\mu}g/l$ for TCE and PCE.

• 센서학회지
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• 제31권4호
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• pp.266-270
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• 2022

Owing to the rising volume of seaborne trade, oil spills damage the marine environment for over 250 yearly. Thus, various analysis methods such as the Fourier-transform infrared (FTIR), Raman spectroscope, and gas chromatography are used to monitor oil spills at sea, but these methods are expensive. Recently, to reduce operational costs, an underwater fluorometer was adopted. However, this approach is not ideal for the remote sensing of oil spills because the device gets submerged in the sea. In this study, we have designed and developed a monitoring system that uses ultraviolet fluorescence to detect spilled oil or water from a distance, as well as proposed an analyzing method defining based on water Raman signal and QF535. Each fluorescence spectrum of water, oil (crude oil), and Bunker A was obtained using the system, and was calculated and analyzed from the spectrum individually. Based on the results of the analysis, we could successfully identity water and oil at a long distance.

• 대한의생명과학회지
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• 제18권4호
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• pp.438-444
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• 2012

N-acylethanolamines (NAEs) including endocannabinoids, anadamide, are long chain fatty acid ethanolamines and express ubiquitously in animal and plant tissues. NAEs have several pharmacological effects including anti-inflammatory, analgesic and anorexic effects. The levels of NAEs in tissues are strictly regulated by synthesizing and hydrolyzing enzymes because NAEs are not stored in the cell but rather made on demand. NAEs are hydrolyzed to free fatty acids and ethanolamines by fatty acid amide hydrolase and N-acylethanolamine-hydrolyzing acid amidase (NAAA). Here, we suggest the fluorescence-based assay system for NAAA. We developed N-(4-methy-2-oxo-2H-chromen-7-yl)palmitamide (PAAC) as a fluorogenic substrate for NAAA and we also generated NAAA stably expressing COSM6 cell line. When extracts of cells expressing NAAA were incubated with PAAC, NAAA specifically hydrolyzed PAAC to palmitic acids and fluorogenic dye, coumarin. Release of coumarin was monitored by using fluorometer. NAAA hydrolyzed PAAC with an apparent Km of $20.05{\mu}M$ and Vmax of 32.18 pmol/mg protein/min. This assay system can be used to develop inhibitors or activators of NAAA.

• Fisheries and Aquatic Sciences
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• 제12권1호
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• pp.70-77
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• 2009

Porphyra yezoensis is known to act as a biofilter against nutrient-rich effluent in seaweed-based integrated aquaculture systems. However, few studies have examined its physiological status under such conditions. In this study, we estimated the photosynthetic activity of P. yezoensis by chlorophyll fluorescence of PSII (${\Delta}F/F'm$ and relative $ETR_{max}$) using the Diving-PAM fluorometer (Walz, Germany). In addition, bioremediation capacity, tissue nutrients, and C:N ratio of P. yezoensis were investigated. The ammonium concentration in seawater of seaweed tank 4 decreased from $72.1{\pm}2.2$ to $33.8{\pm}0.4{\mu}M$ after 24 hours. This indicates the potential role of P. yezoensis in removing around 43% of ammonium from the effluents. Tissue carbon contents in P. yezoensis were constant during the experimental period, while nitrogen contents had increased slightly by 24 hours. In comparison with the initial values, the ${\Delta}F/F'm$ and $rETR_{max}$ of P. yezoensis had increased by about 20 and 40%, respectively, after 24 hours. This indicates that P. yezoensis condition improved or remained constant. These results suggest that chlorophyll fluorescence is a powerful tool in evaluating the physiological status of seaweeds in a seaweed-based integrated aquaculture system.

• ALGAE
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• 제25권3호
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• pp.133-140
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• 2010

Using chlorophyll fluorescence, the vertical migration of benthic diatoms responding to light intensity and affected by sediment grain size was studied. Minimal fluorescence ($F_o$) of surface sediment was measured by imaging pulse amplitude modulated (Imaging-PAM) fluorometer, and used to monitor diatom biomass variation in surface sediments. The test diatoms, Amphora coffeaeformis (C. Agardh) K$\ddot{u}$tzing and Cylindrotheca closterium (Ehrenberg) Reimann & Lewin, migrated to the sediment surface under irradiance from 50 to 500 ${\mu}mol$ photons $m^{-2}s^{-1}$. However, the diatoms exhibited no evident increase of surface biomass under dark conditions, and even showed slightly decrease of surface biomass under irradiances over 1,000 ${\mu}mol$ photons $m^{-2}s^{-1}$. The light intensity inducing the maximum surface migration of A. coffeaeformis was 100 ${\mu}mol$ photons $m^{-2}s^{-1}$, while the light intensity producing the same effect for C. closterium was 250 ${\mu}mol$ photons $m^{-2}s^{-1}$. C. closterium showed higher motility than A. coffeaeformis. Faster diatom surfacing was observed in larger grain size sediments (125-335 ${\mu}m$) than smaller ones (63-125 ${\mu}m$). This study confirmed the significant influence of light as a main triggering factor behind migration, indicated the distinct effect of different sediment grain size, and highlighted the species-specific migratory ability.

• 한국해양환경ㆍ에너지학회지
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• 제10권3호
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• pp.127-137
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• 2007

전기분해 염소소독기로 처리한 결과가 국제해사기구의 협약에서 제시한 생물처리 기준(D-2 regulation)을 만족하는지 확인하기 위해 박테리아, 식물플랑크톤($10-50\;{\mu}m$) 및 동물플랑크톤($>50\;{\mu}m$)의 사멸효과를 확인하였다. 실험조건은 대조구와 잔류염소농도 10 ppm(Expt. 1)과 30 ppm(Expt. 2)을 실험구로 설정하였고, 시험수를 $23.8\;m^3/hr$의 속도로 전기분해염소독기에 통과시켰다. 시험수의 생물조건은 국제해사기구에서 작성된 선박 평형수 관리 장치의 승인을 위한 지침서에서 제시한 기준을 따랐다. 식물플랑크톤의 생사판별은 광학현미경, 형광현미경 및 형광측정기(Turner Designs 10-AU)를 이용하여 확인되었다. 두 농도 조건(10 ppm, 30 ppm)의 처리수에서 운동성이 있는 식물플랑크톤은 움직임이 나타나지 않았고, 형광현미경 하에서 엽록소 형광색이 적색에서 녹색으로 바뀌었으며, 형광값은 고농도(Expt. 1: 6.95, Expt. 2: 7.11)에서 0으로 바뀌었다. 이는 식물플랑크톤의 활성이 상실되어 모두 사멸되었음을 의미한다. 동물플랑크톤의 생사판별은 해부현미경하에서 부속지의 움직임을 토대로 결정되었다. 전기분해 염소소독기 처리 후 해양환경에서 채집되어 농축된 자연군집 동물플랑크톤은 모두 사멸되었으나, 일부 Artemia가 생존하였다. 그러나 각 잔류염소 농도조건의 암소에서 노출시킨 지 24시간 뒤에는 모든 동물플랑크톤이 사멸되었다. 박테리아는 Petrifilm plates($3M^{TM}$)를 이용한 접종배양법으로 처리수의 총 세균, 대장균 군 및 대장균의 사멸효과를 확인한 결과, 균주가 전혀 관찰되지 않았다. 또한 각 염소농도 조건의 처리수에서 추가적으로 노출시킨 5일 동안 세 그룹의 생물에서 재성장이 나타나지 않았다. 본 연구결과는 세 그룹의 생물에 대한 전기분해염소소독기 처리결과가 국제해사기구에서 제정한 선박 평형수 배출기준을 만족시켰음을 보여주었다.