• 한국습지학회지
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• 제20권4호
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• pp.295-303
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• 2018

한국의 내륙습지는 동아시아-대양주 철새 이동경로 상 중요한 번식지 및 월동지를 제공하고 있고, 연안습지는 철새들에게 영양분이 풍부한 중간기착지를 제공하는 역할을 하고 있다. 하지만, 1960년대 이후, 한국은 농경지와 도심 확장을 위해 점진적으로 연안습지를 매립하였고, 야생생물 연안습지 서식지 손실로 인한 이동성 물새 개체수 감소를 야기 하였다. 미국(특히, 미주리주)은 이러한 습지 야생생물 다양성 및 개체수 감소를 막기 위해 습윤토양관리 기법을 개발 하여 야생생물 서식지 보전과 개체수 관리를 하고 있다. 습윤토양관리 기법은 습지 야생생물의 서식지 조건을 최대한 충족하는 상태로 습지를 관리하여 서식지 수용력을 높이는 습지관리 기법이다. 습윤토양관리 지역을 조성하기 위해서는 제방과 물의 흐름을 조절할 수 있는 수문을 만들고, 토양, 지형, 가용한 수원 등을 관리 하여야 한다. 또한, 습윤토양관리 지역은 범람과 배수지역을 정기적으로 특정시기에 관리하고, 다년생 식물생장으로 인한 육상화 억제를 위해 일정기간 동안의 토양교란으로 서식지를 관리 하여야 한다. 이러한 관리 기법은 두가지 목적을 가지고 있는데, 하나는 원하지 않은 식물 생육 통제이고, 다른 하나는 야생생물의 서식지와 먹이원을 최대화 하기 위함이다. 범람과 배수 일정은 지역을 고려한 기후적인 변화에 맞도록 유동적으로 반영하여야 한다. 한국의 위도는 미주리 주와 유사해서 습윤토양관리 기법이 한국에 맞는 효과적인 습지조성 및 관리기법으로 활용될 수 있을 것으로 기대된다. 특히, 이동성 물새(도요 물떼새) 중간기착지와 같은 서식지로의 중요한 역할을 하는 연안습지 인근지역에서 습윤토양관리 기법을 실험적으로 적용하여 한국의 여건(지리, 미기후, 생물종 분포 등)에 맞는지 세부적인 방법을 모색해 보는 연구가 필요하다. 습윤토양관리 기법은 멸종위기 야생생물들에게 주요 서식지를 조성해 줄 뿐만 아니라, 폭넓은 습지 생태계서비스 가치를 함께 제공해 줄 것이다.

• Journal of Microbiology and Biotechnology
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• 제18권3호
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• pp.477-482
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• 2008

A variety of bacterial strains were isolated from waste disposal sites of Uttaranchal, India, and some from artificially developed soil beds containing maleic anhydride, glucose, and small pieces of polyethylene. Primary screening of isolates was done based on their ability to utilize high- and low-density polyethylenes (HDPE/LDPE) as a primary carbon source. Thereafter, a consortium was developed using potential strains. Furthermore, a biodegradation assay was carried out in 500-ml flasks containing minimal broth (250ml) and HDPE/LDPE at 5mg/ml concentration. After incubation for two weeks, degraded samples were recovered through filtration and subsequent evaporation. Fourier transform infrared spectroscopy (FTIR) and simultaneous thermogravimetric-differential thermogravimetry-differential thermal analysis (TG-DTG-DTA) were used to analyze these samples. Results showed that consortium-treated HDPE (considered to be more inert relative to LDPE) was degraded to a greater extent (22.41% weight loss) in comparison with LDPE (21.70% weight loss), whereas, in the case of untreated samples, weight loss was more for LDPE than HDPE (4.5% and 2.5%, respectively) at $400^{\circ}C$. Therefore, this study suggests that polyethylene could be degraded by utilizing microbial consortia in an eco-friendly manner.

• 한국환경과학회지
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• 제17권10호
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• pp.1121-1127
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• 2008

The free-living amoeba and Acanthamoeba sp. are widely distributed in fresh water, soil, air and dust in the world. We studied distribution of amoeba from low Nakdong River(Mulgum and Maeri) and removal efficiency in water treatment process of Busan metropolitan city. During this investigation, water quality showed pH $7.4{\sim}9.6({\pm}1.1)$, water temperature $2.0{\sim}29.0({\pm}17)^{\circ}C$, turbidity $4.8{\sim}27.4({\pm}11.0)$ NTU, chlorophyll-a $10.3{\sim}109.0({\pm}44.3)\;mg/m^{3}$, BOD $1.7\sim4.9({\pm}2.6)$ mg/L, COD $3.1\sim-6.9({\pm}5.0)$ mg/L and total coliform $17\sim920({\pm}200.5)$ MPN/100 mL. The free-living amoeba were detected highly than Acanthamoeba sp., 11 out of 22 in raw water samples were positive (50%) for Acanthamoeba sp. from February 2005 to December 2005. The seasonal characteristics of tree-living amoeba and Acanthamoeba sp. in raw water were mainly distributed through the spring to the early fall. When tree-living amoeba and Acanthamoeba sp. were passed through the water treatment of pilot-plant, approximately 80% was sure to be removed through pre-ozonation, sedimentation, send filtration. 100% was removed after post-ozonation process. All of the isolated amoebas from Nakdong River were Acanthamoeba sp. AC311 18S ribosomal RNA gene with 98% nucleotide sequence homology.

• 미생물학회지
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• 제34권1_2호
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• pp.37-42
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• 1998

토양으로부터 levan을 분해하여 단일종의 fructooligosaccharide를 생산하는 새로운 미생물을 분리 선별하여 본 연구의 공시균주로 선택하였다. Levanase 생산을 위한 최적 배지조성은 0.5% levan, 0.3% yeast extract 0.3% $NaNO_3$, 0.1% $K_2HPO_4$, 0.05% NaCl(pH 8.0)이었으며, 500ml용 shaking flask에 배지 50ml를 넣어 $30^{\circ}C$에서 54시간 배양시켰을 때 목적효소의 생산이 최대에 도달하였다. Levanase에 의해 생성되는 생성물은 단일종의 oligo당임이 확인되었으며 측쇄가 많은 levan으로부터는 소량의 측쇄구조를 가진 oligosaccharide로 추정되는 미지의 물질이 부산물로 생성되었다. 생성 oligo당을 순수하게 정제하여 HPLC 및 ESI-MASS로 중합도를 조사한 결과 DP가 7인 levanheptaose임이 판명되었다.

• Journal of Microbiology and Biotechnology
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• 제4권2호
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• pp.113-118
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• 1994

A bacterial strain NS-83 isolated from soil was able to produce an extracellular thermostable protease. The strain was identified as Pseudomonas aeruginosa based on its morphological and physiological characteristics. A thermostable protease from this strain has been purified to homogeneity as judged by SDS-PAGE and isoelectric focusing. The purification procedures included hydrophobic interaction, ion exchange, and gel filtration chromatography. The $M_r$ and the pl of the enzyme were 32,000 and 5.9, respectively. The optimal pH at 55$^{\circ}C$ and the optimal temperature at pH 7.0 were 8.0 and 60$^{\circ}C$, respectively. The D-values of the enzyme at 60, 65, and 70$^{\circ}C$ were 22, 2.1, and 0.75 hrs, respectively. The enzyme activity was significantly inhibited in the presence of 1 mM o-phenanthroline or EDTA, suggesting that the enzyme is metalloprotease. The $K_m$, and $V_{max}$ for Hammarsten casein were found to be 3.2 mg/ml and 0.918 unit/ml, respectively. These enzymatic properties were similar to those of elastase produced from P. aeruginosa IFO 3455, but the enzyme was clearly different from the reported elastase, in respect to $Ca^{++}$ effects on enzyme-thermostability. This property, together with amino acid composition analysis, confirmed that the enzyme differs from the known P. aeruginosa elastase.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권1호
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• pp.17-22
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• 2004

A bacterial strain WJ-98 found to produce active extracellular keratinase was isolated from the soil of a poultry factory. It was identified as Paracoccus sp. based on its 16S rRNA sequence analysis, morphological and physiological characteristics. The optimal culture conditions for the production of keratinase by Paracoccus sp. WJ-98 were investigated. The optimal medium composition for keratinase production was determined to be 1.0% keratin, 0.05% urea and NaCl, 0.03% K$_2$HPO$_4$, 0.04% KH$_2$PO$_4$, and 0.01% MgCl$_2$$.$6H$_2$O. Optimal initial pH and temperature for the production of keratinase were 7.5 and 37$^{\circ}C$, respectively. The maximum keratinase production of 90 U/mL was reached after 84 h of cultivation under the optimal culturing conditions. The keratinase from Paracoccus sp. WJ-98 was partially purified from a culture broth by using ammonium sulfate precipitation, ion-exchange chromatography on DEAE-cellulose, followed by gel filtration chromatography on Sephadex G-75. Optimum pH and temperature for the enzyme reaction were pH 6.8 and 50$^{\circ}C$, respectively and the enzymes were stable in the pH range from 6.0 to 8.0 and below 50$^{\circ}C$. The enzyme activity was significantly inhibited by EDTA, Zn$\^$2+/ and Hg$\^$2+/. Inquiry into the characteristics of keratinase production from these bacteria may yield useful agricultural feed processing applications.

• Journal of Microbiology and Biotechnology
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• 제25권9호
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• pp.1449-1459
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• 2015

A novel proteolytic enzyme with fibrinolytic activity, FSP3, was purified from the recently isolated Streptomyces sp. P3, which is a novel bacterial strain isolated from soil. FSP3 was purified to electrophoretic homogeneity by ammonium sulfate precipitation, anion exchange, and gel filtration. FSP3 is considered to be a single peptide chain with a molecular mass of 44 kDa. The maximum activity of the enzyme was observed at 50℃ and pH 6.5, and the enzyme was stable between pH 6 and 8 and below 40℃. In a fibrin plate assay, FSP3 showed more potent fibrinolytic activity than urokinase, which is a clinical thrombolytic agent acting as a plasminogen activitor. The activity was strongly inhibited by the serine protease inhibitor PMSF, indicating that it is a serine protease. Additionally, metal ions showed different effects on the activity. It was significantly suppressed by Mg²⁺ and Ca²⁺ and completely inhibited by Cu²⁺, but slightly enhanced by Fe²⁺. According to LC-MS/MS results, its partial amino acid sequences are significantly dissimilar from those of previously reported fibrinolytic enzymes. The sequence of a DNA fragment encoding FSP3 contained an open reading frame of 1287 base pairs encoding 428 amino acids. FSP3 is a bifunctional enzyme in nature. It hydrolyzes the fibrin directly and activates plasminogen, which may reduce the occurrence of side effects. These results suggest that FSP3 is a novel serine protease with potential applications in thrombolytic therapy.

• Journal of Microbiology and Biotechnology
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• 제10권2호
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• pp.238-243
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• 2000

An exoinulinase (${\beta}-D-fructofuranosidase$) gene was cloned by chromosome walking along the upstream region of the endoinulinase gene of Pseudomonas mucidolens isolated from soil. the exoinulinase gene consisted of an ORF of 0,506 bp encoding a polypeptide of 501 amino acids with a deduced molecular weight of 55,000. The exoinulinase produced by the recombinant Escherichia coli $DH5{\alpha}$ strain was also purified to homogeneity as determined by SDS-PAGE and a zymogram. The molecular weight of the purified exoinulinase according to both SDS-PAGE and gel filtration matched the deduced molecular weight of the protein described above, thereby indicating that the native form of the exoinulinase was a monomer. The purified enzyme hydrolyzed activity value of 2.0. Furthermore, no inulo-oligomers were liberated from the inulin substrate in the enzymatic reaction mixtures incubated for 90 min at $55^{\circ}C$. Taken together, these results indicate that the purified ${\beta}-D-fructofuranosidase$ was an exoinulinase. The pH and temperature optima of the exoinulinase were pH 6.0 and $55^{\circ}C$, respectively. the enzymehad no apparent requirement for a cofactor, and its activity was completely inactivated by $Ag^{+},{\;}Hg^{2+},{\;}and{\;}Zn^{2+}$. Kinetic experiments gave $K_m,{\;}V_{max},{\;}and{\;}K_{cat}$ values for inulin of 11.5 mM, 18 nM/s, and $72{\;}s^{-1}$, respectively. the exoinulinase was fairly stable in broad pH conditions (pH 5-9), and at pH 6.0 it showed a residual activity of about 70% after 4 h incubation at $55^{\circ}C$.

• 환경위생공학
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• 제14권2호
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• pp.56-67
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• 1999

This study was performed to suggest the basic data and plans for the establishment of safe water supply plans in simple water supply piped system in the rural areas. In 4 different places, 24 points of water sources 36 points of taps from water sources were sampled. Of the whole 60 points, 55 points were ground water and 5 points were surface water. 14 items were measured for the analysis of water quality on each samples. The measured items were analyzed again by statistical method ; cluster analysis and principle components analysis. The results of this study are as followed. 1) In water quality analysis on water sources, 4 items, bacteria, E.coli, NH3-N and Fe exceed the standard. Of 24 points, 20 points(83%) on bacteria, 1 point(4%) on NH3-N and Fe exceed the standard. 2) In water quality analysis on near and remote taps, 4 items, bacteria, E.coli, NH3-N and Fe , exceed the standard. Of 36 points, 20 points (81%) on bactria, 1 pint(3%) on NH3-N and Fe exceed the standard. 3)Cluster analysis on water quality shows the differences by the kinds of water sources, geographical characteristics and distance from water sources. 4) Principle components analysis on ground water shows that Factor 1 and Factor 3 are natural fluctuation by the content of soil. Also, Factor 2 and Factor 4 are penetration of pollutants to underground. Therefore, it is needed to take deeper ground water in order to prevent from pollution in the areas which have ground water as water source . 5) Principle components analysis on surface water shows that Factor 1 is penetration of vacteria from surface to water source when rainfalls. Also, Factor 2 is fluctuation of water quality by the geographical characteristics. Therefore, the counterplans against non-point pollution source must be taken. Filtration and disinfection facilities are needed in the areas which have surface water as water source.

• BMB Reports
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• 제35권6호
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• pp.568-575
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• 2002

An $\alpha$-amylase (EC 3.2.1.1) was purified that catalyses the production of a high level of maltose from starch without the attendant production of glucose. The enzyme was produced extracellularly by thermophilic Streptomyces sp. that was isolated from Thailand's soil. Purification was achieved by alcohol precipiation, DEAE-Cellulose, and Gel filtration chromatographies. The purified enzyme exhibited maximum activity at pH 6-7 and $60^{\circ}C$. It had a relative molecular mass of 45 kDa, as determined by SDS-PAGE. The hydrolysis products from starch had $\alpha$-anomeric forms, as determined by $^1H$-NMR. This maltose-forming $\alpha$-amylase completely hydrolyzed the soluble starch to produce a high level of maltose, representing up to 90%. It hydrolyzed maltotetrose and maltotriose to primarily produce maltose (82% and 62%, repectively) without the attendant production of glucose. The high maltose level as a final end-product from starch and maltooligosaccharides, and the unique action pattern of this enzyme, indicate an unusual maltose-forming system. After the addition of the enzyme in the bread-baking process, the bread's volume increased and kept its softness longer than when the bread had no enzyme.