• 보존과학연구
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• 통권26호
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• pp.5-25
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• 2005

A consideration number of investigation have begun to elucidate the essential role biological agents play in the deterioration of stone. What is becoming clear is that many factors affect the durability of stone. Physical, chemical, and biological agentsact in co-association, ranging from synergistic to antagonistic, to deteriorate stone. Biodeterioration has usually been considered to be a degradation process following the initial deterioration effects of inorganic agents, especially objects of cultural value such as pagoda, stature of Buddha etc. These agents were thought to condition stone surfaces for microbial contamination due to structural changes and enrichment of inorganic organic nutrient substrates. This report concentrates on the action of biodeteriogens from bacteria to algae and higher plants. Preventive and remedial methods are surveyed, as are a selection of chemical treatments.

• 농약과학회지
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• 제4권4호
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• pp.26-30
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• 2000

토양미생물 및 잔디 추출액에 의한 제초제 dicamba의 분해성을 평가하기 위하여 본 실험을 수행하였다. Dicamba를 분해하는 토양미생물 5종을 enrichment culture에 의해 토양으로부터 분리하였으며, 이들 균주는 Acidovorax sp., Alcaligenes sp. 및 Variovorax sp.로 동정되었다. Dicamba를 10 ppm 수준으로 처리한 무기배지에서 분리균에 의한 dicamba 분해는 배양 21일 후에 평균 90% 이상이었으며, 분해산물로 5-hydroxydicamba가 검출되었다. 한국잔디 (Zoysia Japonica S.)를 phosphate buffer로 추출하여 추출액에 의한 dicamba 분해를 조사한 결과 dicamba의 반감기는 $2.5{\sim}2.7$일 이었으며, 대사산물로 소량의 4- 및 5-hydroxydicamba가 검출되었다.

• KSBB Journal
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• 제28권5호
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• pp.295-302
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• 2013

Indigo is utilized in various industries including textile dyeing, cosmetics, printing and medicinal products and its reduced form, leuco-indigo, is mainly used in these process. Chemical reducing agent (sodium dithionite, sodium sulfide, etc.) is preferred to use for the formation of leucoindigo in industry. In traditional indigo fermentation process, microorganisms can participate in the reduction of indigo and thus it has been known to reduce environmental pollution and noxious byproducts. However, in fermentation method using microorganisms it is difficult to standardize large scale production process due to low yield and reproducibility. In this study, we attempted to develop the indigo reduction process using microbial flora which was isolated from naturally fermented indigo vat or deduced by metagenomic approach. From the results of library analyses of PCR-amplified 16S rRNA genes from the traditional indigo fermentation vat sample (metagenome), it was confirmed that Alkalibacteriums (71%) was distinctly dominant in population. Some strains were identified after confirming that they become pure culture in nutrient media modified slightly. Four strains were separated in this process and each strain showed obvious reducing ability toward indigo in dyeing test. It is expected that the analyzed results will provide important data for standardizing the natural fermentation of indigo and investigating the mechanism of indigo reduction.

• Ocean and Polar Research
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• 제35권2호
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• pp.85-92
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• 2013

The coral symbiotic algae zooxanthellae is often expelled from the host as the host coral is under physiological stress, causing the coral to turn completely white. Such coral bleaching events are occurring more frequently with the increase in the global warming, ocean acidification and increased level of anthropogenic impacts such as eutrophication. In the present study, we investigated the effects of inorganic nutrients including ammonium, nitrate, phosphate and elevated water temperature on the symbiotic zooxanthellae density in the fragment of branching coral Acropora nobilis. Zooxanthellae density in the host coral decreased 8 hrs after the experiment at a given elevated water temperature ($32^{\circ}C$, p < 0.05). In contrast, no clear coral bleaching or decrease in the symbiotic algae density was observed from the branching coral exposed to a normal water temperature of $30^{\circ}C$ and high levels of nutrients such as 20 ${\mu}M$ of $NH_4Cl$, 20 ${\mu}M$ of $NaNO_3$ and, 10 ${\mu}M$ $KH_2PO_4$. Accordingly, the data indicated high water temperature is one of the stressful factors to cause bleaching in A. nobilis, whereas the high levels of nutrients is not a factor. It is believed that the results obtained in the present study are useful as baseline information in the management of the coral reefs.

• 생태와환경
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• 제48권4호
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• pp.287-295
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• 2015

본 연구는 2014년 9월과 2015년 3월에 채수한 팔당호 3지점의 현장수 (PD-1, PD-2 및 PD-3)를 이용하여 북한강에서 우점하는 A. circinalis의 휴면포자 발아 및 성장 잠재력을 평가하였다. 질소와 인 농도는 팔당댐앞 (PD-1)과 광동교 (PD-3)에 비교하여 금남리 (PD-2)에서 좀 더 높게 나타났다. 팔당호 3지점의 총질소에 대한 영양상태지수 (TSI)는 65~85의 범위로 나타났으며, 부영양 또는 과영양 상태로 평가되었다. 또한 총인에 대한 영양상태지수(TSI) 값은 49~68의 범위로서, 중영양 또는 부영양 상태로 평가되었다. 휴면포자 발아 잠재력은 영양염 농도가 높은 금남리 지점 (PD-2)에서 좀 더 높게 나타났으며, 영양세포 성장 잠재력도 영양염 농도가 높은 현장수에서 증가하였다.

• 생태와환경
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• 제42권4호
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• pp.422-431
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• 2009

This study was to provide basic data for aquatic ecosystem research using fishes. Field sampling was carried out at five selected sites of Gap Stream, and fish samples, especially for a selection of sentinel species were collected three times in June, September, and October 2007. We analyzed total length distribution of Zacco platypus in relation with the season and the sampling sites, and then compared with total body weight, condition factor (K), and age distribution of the fish. The fish population data were compared with physico-chemical water quality, obtained from the Ministry of Environment, Korea. Water quality analysis showed a significant nutrient enrichment, based on total nitrogen (TN) and total phosphorus (TP), and organic matter pollution, based on biological oxygen demand (BOD) and chemical oxygen demand (COD) in the Site 5, which is directly influenced by wastewater disposal plant (WDP). Population analysis of the sentinel species showed that the total number of individuals, age distribution, and the population size-structure were influenced by the effluents from the WDP, and that reproductive failure of young-age population were evident in Site 5. According to the relation analysis of total weight to K, the disturbed population was mainly attributed to combined effects of habitat modifications and chemical degradations. Regression analysis of K values against water quality parameters showed significant (p<0.05) positive relations with nutrient and organic matter contents. Our data suggest that the population structure using a sentinel fish species reflected the ambient water quality in the stream and that diagnosis of aquatic ecosystem health using Z. platypus population may be practical for water resource and ecosystem conservations.

• 한국해양학회지
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• 제26권3호
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• pp.242-254
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• 1991

한국남해역의 일차생산력을 한국해양연구소의 3, 4, 8, 11월 4회에 걸친 현장조사 에서 측정하였다. 조사해역에서 일차생산력이 높게 나타나는 곳은 전선구조와 밀접한 관계가 있는 듯하다. 1990년 3월과 1989년 11월에는 대마, 난류수와 중국대륙연안수 사이에 비교적 높은 일차생산력이 나타났다. 1988년 8월에는 한국남서해안의 조석전선 에서 비교적 일차생산력이 높았다. 전선구조에 따른 영양염의 공급이 일차생산력을 증 가시키는 요인이라 생각되나 물리적 환경과 영양염의 공급구조등에 대한 과정은 명확 하지 않다. 수층의 평균 일차생산력은 1989년 4월에 1,727 mgC/m$^2$/day 로 가장 높았 고 1990년 3월과 1989년 11월에는 각각 314, 517 mgC/m$^2$/day 였다. 중국대륙연안수의 영향을 받는 곳에서는 높은 탁도에 의한 투과광량의 감소가 낮은 일차생산력의 원인인 것 같다.

• BMB Reports
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• 제56권11호
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• pp.600-605
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• 2023

Intrahepatic cholangiocarcinoma (ICC) is a bile duct cancer and a rare malignant tumor with a poor prognosis owing to the lack of an early diagnosis and resistance to conventional chemotherapy. A combination of gemcitabine and cisplatin is the typically attempted first-line treatment approach. However, the underlying mechanism of resistance to chemotherapy is poorly understood. We addressed this by studying dynamics in the human ICC SCK cell line. Here, we report that the regulation of glucose and glutamine metabolism was a key factor in overcoming cisplatin resistance in SCK cells. RNA sequencing analysis revealed a high enrichment cell cycle-related gene set score in cisplatin-resistant SCK (SCK-R) cells compared to parental SCK (SCK WT) cells. Cell cycle progression correlates with increased nutrient requirement and cancer proliferation or metastasis. Commonly, cancer cells are dependent upon glucose and glutamine availability for survival and proliferation. Indeed, we observed the increased expression of GLUT (glucose transporter), ASCT2 (glutamine transporter), and cancer progression markers in SCK-R cells. Thus, we inhibited enhanced metabolic reprogramming in SCK-R cells through nutrient starvation. SCK-R cells were sensitized to cisplatin, especially under glucose starvation. Glutaminase-1 (GLS1), which is a mitochondrial enzyme involved in tumorigenesis and progression in cancer cells, was upregulated in SCK-R cells. Targeting GLS1 with the GLS1 inhibitor CB-839 (telaglenastat) effectively reduced the expression of cancer progression markers. Taken together, our study results suggest that a combination of GLUT inhibition, which mimics glucose starvation, and GLS1 inhibition could be a therapeutic strategy to increase the chemosensitivity of ICC.

• Journal of Plant Biotechnology
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• 제35권4호
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• pp.337-343
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• 2008

We generated transgenic tomato plants with Arabidopsis thaliana $H^+$/cation exchanger gene (C4X4) by Agrobactrium-mediated transformation. We confirmed transgene copy number and transcription by Southern and Northern blot analyses. The intact CAX4-expressing tomato (Lycopersicon esculentum) fruits contained 63-71% more calcium ($Ca^{2+}$) than wild-type fruits. Moreover, ectopic expression of C4X4 in tomato fruits did not show any significant increase of the four kinds of metallic cations analyzed ($Mg^{2+}$, $Fe^{2+}$, $Mn^{2+}$, and $Cu^{2+})$. The C4X4-expressing tomato plants including their fruits did not show any morphological alternations during whole growth period. These results suggest the enhanced Ca-substrate specificity of CAX4 exchanger in tomato. Therefore, intact CAX4 exchanger can be a useful tool for $Ca^{2+}$ nutrient enrichment of tomato fruits with reduced accumulation of undesirable cations.

• Journal of Microbiology and Biotechnology
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• 제8권1호
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• pp.61-66
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• 1998

A microorganism which degrades phenol and co-metabolizes trichloroethylene (TCE) was isolated from Yangsan stream after enrichment in a medium containing phenol as the sole carbon source. The isolate EL-43P was identified as the genus Rhodococcus by its morphological, cultural and physiological characteristics. Phenol-induced cells of Rhodococcus sp. EL-43P degraded TCE. Toluene and nutrient broth could not replace the phenol requirement. The optimal conditions of initial pH and temperature of media for growth were 7.0~9.0 and $30~50^{\circ}C$, respectively. Rhodococcus sp. EL-43P could grow with phenol up to 1,000 ppm. Growth was inhibited by phenol at a concentration above 1,500 ppm. It was observed that Rhodococcus sp. EL-43P was able to degrade 90% of phenol (1,000 ppm) after 40 h in a culture. Phenol-induced cells of Rhodococcus sp. EL-43P degraded 95% of $5{\mu}M$ TCE in 6 h. Rhodococcus sp. EL-43P hardly degraded TCE above $100{\mu}M$.