• Microbiology and Biotechnology Letters
• /
• v.48 no.3
• /
• pp.358-365
• /
• 2020

An organic solvent- and bleach-stable protease-producing strain was isolated from a polluted river water sample and identified as Aeromonas veronii OB3 on the basis of biochemical properties (API 20E) and 16S rRNA sequence analysis. The strain was found to hyper-produce alkaline protease when cultivated on fish waste powder-based medium (HVSP, 4080 U/ml). The biochemical properties and compatibility of OB3 with several detergents and additives were studied. Maximum activity was observed at pH 9.0 and 60℃. The crude protease displayed outstanding stability to the investigated surfactants and oxidants, such as Tween 80, Triton X-100, and H₂O₂, and almost 36% residual activity when incubated with 1% SDS. Remarkably, the enzyme demonstrated considerable compatibility with commercial detergents, retaining more than 100% of its activity with Ariel and Tide (1 h, 40℃). Moreover, washing performance of Tide significantly improved by the supplementation of small amounts of OB3 crude protease. These properties suggest the potential use of this alkaline protease as a bio-additive in the detergent industry and other biotechnological processes such as peptide synthesis.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2012.05a
• /
• pp.641-641
• /
• 2012

하천관련 정보관리기술의 발전을 위해서는 관련자료 출처 발굴과 자료의 통합관리 및 분석 기술개발 등의 노력이 필요하다. 이에 따라 하천관련 정보에 대한 관리기술의 선진사례 분석을 통하여 국외의 앞선 기술을 살펴보고 국내 적용 방안을 제시하고자 한다. 본 연구에서 분석한 미국의 HIS (Hydrologic Information System)는 CUAHSI (Consortium of Universities for the Advancement of Hydrologic Science, Inc)에서 수행하는 연구 활동의 하나로서 개방형 프로젝트로 개발되고 있으며 수문분석에 필요한 정보를 통합하여 관리하고 배포하는 기능을 수행하고 있다. CUAHSI-HIS는 웹기반 시스템이며 HIS 중심부(데이터 목록), Hydro 서버(데이터 게시), HydroDesktop (사용자 검색툴)으로 구성되어 있다. 이 세 개의 핵심 요소들은 상호작용을 통해 운영되며 미국 내의 모든 물관련 자료를 발굴하고 수집한다. 이렇게 발굴 수집된 자료는 WaterML로 표준화하여 다양한 사용자가 쉽게 사용할 수 있도록 제공된다. 국내의 경우 RIMGIS와 WAMIS 등이 하천정보를 제공하고 있지만 변화된 하천운영 환경을 반영하여 사용자에게 보다 체계적이고 효율적인 정보를 제공하기 위해서는 정보의 표준화 및 시스템 구성환경 등 다양한 측면에서 검토가 필요하다. 이를 위해 CUAHSI-HIS 연구사례를 벤치마킹하여 국내 실정에 맞는 적용방안을 수립하여 구축하게 된다며 체계적인 정보관리 및 활용성을 극대화할 수 있을 것으로 사료된다.

• The Korean Journal of Ecology
• /
• v.17 no.1
• /
• pp.79-90
• /
• 1994

Water samples were taken at 6 stations from the mouth of Keum River to Kogunsan Archipelago of West Sea during December, 1991 to August, 1992, to determine the distribution of heterotrophic bacteria, their biovolumes and heterotrophic activities. Heterotrophic marine bacteria ranged from $1.0\;{\times}\;10^3to\;5\;{\times}\;10^5c.f.u.$ /ml. As for morphological distribution measured by epifluorescence microscopy, rod-shaped bacteria were between 45% and 72% of all cells during investigation period. Average biovolume of sampled bacteria ranged from $(7.69\;{\pm}\;0.18)\;{\times}10^{-2}to\;(8.18\;{\pm}\;0.38)\;{\times}\;10^{-2}\;{\mu}m^3$ for coccoid bacteria, and from $(6.09\;{\pm}\;0.29)\;{\times}10^{-2}to\;(7.72\;{\pm}\;0.41)\;{\times}\;10^{-2}\;{\mu}m^3$ for rod-shaped ones. The activities of extracellular enzymes ranged from 0.01 to 2.6 ${\mu}M$ /l /hr for glucosidase, from 0.01 to 2.6 ${\mu}M$ /l /hr for amylase, from 0.01 to 8.86 ${\mu}M$ /I /hr phosphatase and from 0.01 to 0.94 ${\mu}M$ /l /hr for chitinase. Extracellular enzyme activities were higher in summer season than in other sampling periods, and phosphatase showed the highest activity among measured extracellular enzymes. Bacterial distribution and their extracellular enzyme activities were associated with water temperature and organic nutrients, but bacterial cell volumes showed no direct relationship with extracellular enzyme activities.

• Journal of Soil and Groundwater Environment
• /
• v.18 no.1
• /
• pp.67-77
• /
• 2013

To improve the energy efficiency of conventional thermal treatment, soil remediation with microwave has been studied. In this study, the remediation efficiency of contaminated soil with semi-volatile organic contaminants were evaluated with microwave oven and several additives such as water, formic acid, iron powder, sodium hydroxide (NaOH) solution, and activated carbon. For the experiment, loamy sand and sandy loam collected from Imjin river flood plain were intentionally contaminated with hexachlorobenzene and phenanthrene, respectively. The contaminated soils were treated with microwave facility and the mass removals of organic contaminants from soils were evaluated. Among additives that were added to increase the remediation efficiency, activated carbon and NaOH solution were more effective than water, iron powder, and formic acid. When 10 g of hexachlorobenzene (142.4 mg/kg-soil) or phenanthrene (2,138.8 mg/kg-soil) contaminated soil that mixed with 0.5 g iron powder, 0.5 g activated carbon and 1 ml 6.25 M NaOH solution were treated with microwave for 3 minutes, more than 95% of contaminants were removed. The degradation of hexachlorobenzene during microwave treatments with additives was confirmed by the detection of pentachlorobenzene and tetrachlorobenzene. Naphthalene and phenol were also detected as degradation products of phenanthrene during microwave treatment with additives. The results showed that adding a suitable amount of additives for microwave treatments fairly increased the efficiency of removing semi-volatile soil organic contaminants.

• Journal of Microbiology and Biotechnology
• /
• v.26 no.3
• /
• pp.579-587
• /
• 2016

Mastitis is a prevalent inflammatory disease that remains one of the main causes of poor quality of milk. Phytoncides are naturally occurring anti-inflammatory compounds derived from plants and trees. To determine if treatment with phytoncide could decrease the severity of lipopolysaccharide (LPS)-induced inflammatory responses, mammary alveolar epithelial cells (MAC-T) were pretreated with phytoncide (0.02% and 0.04% (v/v)) followed by LPS treatment (1 and 25 μg/ml). The results demonstrated that phytoncide downregulated LPS-induced pro-inflammatory cyclooxygenase-2 (COX-2) expression. Additionally, LPS-induced activation of ERK1/2, p38, and Akt was attenuated by phytoncide. Treatment of cells with known pharmacological inhibitors of ERK1/2 (PD98059), p38 (SB203580), and Akt (LY294002) confirmed the association of these signaling pathways with the observed alterations in COX-2 expression. Moreover, phytoncide attenuated LPS-induced NF-κB activation and superoxide production, and, finally, treatment with phytoncide increased Nrf2 activation. Results suggest that phytoncide can decrease LPS-induced inflammation in MAC-T cells.

• Journal of information and communication convergence engineering
• /
• v.7 no.4
• /
• pp.580-585
• /
• 2009

Harmful Algal Blooms (HABs), caused by Cochlodinium polykrikoides that causative fishery mortality, impact on aquaculture and economic loss appear particularly in summer and fall seasons in the Korean seas. It was studied on characteristics of HABs in the South Sea of Korea by using satellite and in-situ data. The in-situ data encompassed oceanic and meteorological data from July to October 2002-2008 and satellite data from July to October 2002-2006. Chlorophyll concentrations were calculated using Seaviewing Wide Field-of-view Sensor images by an Ocean Color (OC4) algorithm, and HABs were estimated using the Red tide index Chlorophyll Algorithm (RCA). The HAB occurrences were dominant when water temperature was $22.6-28^{\circ}C$ in August. The frequency of the individual numbers during 2002-2008, the HABs more than 1000 cells/ml (alert condition), were 73.57 %. In meteorological data from July to September during 2002-2008, the average precipitation, the mean air temperature, the mean wind speed and direction, and the sunshine were 9.31 mm/day, $24.07^{\circ}C$, 2.34 m/s and easterly, and 1-11 h, respectively. Our results suggest that the upwelling is caused by southwesterly wind in summer season and the Tsushima Warm Current which have influenced on the dispersion and moving of HAB (chlorophyll). In addition, the fresh water from Nakdong River, as the source of nutrients, also influences the occurrence of HABs.

• Korean Journal of Microbiology
• /
• v.17 no.4
• /
• pp.187-192
• /
• 1979

Dennis (1972) reported that Trichosporon cutaneum FRI-425 from the petioles of Pheum rhamponticum var, had showed the celluloytic activity. Chun (1977) also suggested that Trichoporon pullulons 225 isolated from the saline water of the Yeoung San River had a similar properties. However, the assay conditions for enzyme activity were not yet investigated. Thus, the present work was undertaken to examine some conditions for CMCase activity and at the same time to compare the activities of crude enzyme produce from above two species of Trichosporon pullulans. The results are as follows; 1. The maximum production of total reducing sugar by crude enzyme of Tr. pululans was after 30 minutes, whereas that of Tr. cutanuem FRI-425 was after 90 minutes. This fact showed that the reaction velocity of enzyme from Tr. pullulans 225 was more faster than that of Tr. cutaneum FRI-425. 2. Two species showed a similar trend to increase the production of reducing sugar in proportion to the increment in substrate concentration and to arrive at maximum level at lmg/ml of substrate concentration. However, Tr. pullulans 225 produced more $50{\mu}g$ of reducing sugar compared to Tr. cutaneum. 3. The optimum PH for CMCase activity is 5.0 for Tr. pullulans 225 as well as Tr. cutaneum FRI-425, and PH stability lie within the range of 6 and 8. In the activity and stability of enzyme on PH changes, enzyme of Tr. cutaneum FRI-425 was more unstable than that of TY. pullulans 225. 4. The optimum temperature for CMCase activity was $40^{\circ}C$, and enzyme activity from Tr. pullulans 225 was more sensitive to temperature changes compared with that of TY. cutaneum. The heat stability was within $40^{\circ}C$, but that was rapidly decreased above $40^{\circ}C$. In comparison of the heat stability for enzyme of Tr. cutaneum FRI-425 with that of Tr. pullulans 225 at the same temperature of $80^{\circ}C$, the former was some 10 percent more stable than the latter.

• Journal of Korean Society on Water Environment
• /
• v.33 no.3
• /
• pp.326-333
• /
• 2017

The lakes and reservoirs have been reported as important sources of carbon emissions to the atmosphere in many countries. Although field experiments and theoretical investigations based on the fundamental gas exchange theory have proposed the quantitative amounts of Net Atmospheric Flux (NAF) in various climate regions, there are still large uncertainties at the global scale estimation. Mechanistic models can be used for understanding and estimating the temporal and spatial variations of the NAFs considering complicated hydrodynamic and biogeochemical processes in a reservoir, but these models require extensive and expensive datasets and model parameters. On the other hand, data driven machine learning (ML) algorithms are likely to be alternative tools to estimate the NAFs in responding to independent environmental variables. The objective of this study was to develop random forest (RF) and multi-layer artificial neural network (ANN) models for the estimation of the daily $CO_2$ NAFs in Daecheong Reservoir located in Geum River of Korea, and compare the models performance against the multiple linear regression (MLR) model that proposed in the previous study (Chung et al., 2016). As a result, the RF and ANN models showed much enhanced performance in the estimation of the high NAF values, while MLR model significantly under estimated them. Across validation with 10-fold random samplings was applied to evaluate the performance of three models, and indicated that the ANN model is best, and followed by RF and MLR models.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2015.05a
• /
• pp.626-626
• /
• 2015

본 연구에서는 하천공간정보의 웹서비스를 위해 SOAP(Simple Object Access Protocol) API 및 REST(Representation State Transfer) API로 제공하는 HydroG-OneFlow 웹서비스를 개발하였다. HydroG-OneFlow는 GML 기반의 서비스를 제공하며 GetBasin, GetGeoVariable 및 GetData 등의 기본서비스로 구성된다. GML은 GIS S/W의 벡터 GML 포맷과 공간정보 오픈플랫폼 서비스인 브이월드 데이터 API에서 제공하는 GML 포맷을 참고하여 하천공간 벡터정보를 제공할 수 있도록 GML을 구성하였다. GDM 공간 데이터에 대한 벡터정보 ML 수용 수준을 향상시킬 수 있도록 벡터구조의 점, 선, 면 정보에 대하여 GML의 PointPropertyType, CurvePropertyType, SurfacePropertyType을 도입하였다. 또한 일반적인 공간자료에서는 Multi 객체에 대한 지원도 필요하다. 현 GDM 데이터베이스에서도 OGC 표준의 MultiPoint, MultiLineString, MultiPolygon을 지원하고 있다. 이를 위하여 GML의 상응 요소인MultiPointPropertyType, MultiCurvePropertyType, MultiSurfacePropertyType을 하천공간정보 벡터 스키마에 도입하여 활용하였다. 클라이언트 서버 통신은 메시지 교환프로토콜인 SOAP을 사용하여 서버의 객체를 직접 호출하여 이루어진다. 서버는 서버의 제공 서비스를 WSDL(Web Service Description Language)를 통하여 게시하고 클라이언트는 이 기준(Criteria)을 참고하여 접근한다. GetData의 경우 Type(GRID or VECTOR), GDM(Geospatial Data Model) 여부(true or false), LayerName, BasinID, GenTime을 인자로 받아 GeoData에서 검색된 정보를 반환한다. SOAP버전은 1.1과 1.2를 지원하여 접근하는 클라이언트에서 선택할 수 있도록 개발하였다.

• Journal of Korean Society of Water and Wastewater
• /
• v.34 no.6
• /
• pp.463-471
• /
• 2020

A 1,000 ㎥/d DAF(dissolved air flotation) pilot plant was installed to evaluate the performance of the floating process using the Nakdong River. Efficiency of various DAF operations under different conditions, such as hydraulic loading rate, coagulant concentration was evaluated in the current research. The operation conditions were evaluated, based on the removal or turbidity, TOC(total organic carbon), THMFP(trihalomethane formation potential), Mn(manganese), and Al(aluminum). Also, particle size analysis of treated water by DAF was performed to examine the characteristics of particles existing in the treated water. The turbidity removal was higher than 90%, and it could be operated at 0.5 NTU or less, which is suitable for the drinking water quality standard. Turbidity, TOC, and THMFP resulted in stable water quality when replacing the coagulant from alum to PAC(poly aluminum chloride). A 100% removal of Chl-a was recorded during the summer period of the DAF operations. Mn removal was not as effective as where the removal did not satisfy the water quality standards for the majority of the operation period. Hydraulic loading of 10 m/h, and coagulant concentrations of 40 mg/L was determined to be the optimal operating conditions for turbidity and TOC removal. When the coagulant concentration increases, the Al concentration of the DAF treated water also increases, so coagulant injection control is required according to the raw water quality. Particle size distribution results indicated that particles larger than 25 ㎛ showed higher removal rates than smaller particles. The total particel count in the treated water was 2,214.7 counts/ml under the operation conditions of 10 m/h of hydraulic loading rate and coagulant concentrations of 60 mg/L.