• Journal of Microbiology and Biotechnology
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• 제28권5호
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• pp.784-795
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• 2018

Bacillus amyloliquefaciens Pc3 was isolated from Antarctic seawater with antifungal activity. In order to investigate the metabolic regulation mechanism in the biosynthesis of lipopeptides in B. amyloliquefaciens Pc3, GC/MS-based metabolomics was used when exogenous indole was added. The intracellular metabolite profiles showed decreased asparagine, aspartic acid, glutamine, glutamic acid, threonine, valine, isoleucine, hexadecanoic acid, and octadecanoic acid in the indole-treated groups, which were involved in the biosynthesis of lipopeptides. B. amyloliquefaciens Pc3 exhibited a growth promotion, bacterial total protein increase, and lipopeptide biosynthesis inhibition upon the addition of indole. Besides this, real-time PCR analysis further revealed that the transcription of lipopeptide biosynthesis genes ituD, fenA, and srfA-A were downregulated by indole with 22.4-, 21.98-, and 26.0-fold, respectively. It therefore was speculated that as the metabolic flux of most of the amino acids and fatty acids were transferred to the synthesis of proteins and biomass, lipopeptide biosynthesis was weakened owing to the lack of precursor amino acids and fatty acids.

• Environmental Analysis Health and Toxicology
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• 제15권3호
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• pp.61-67
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• 2000

Toxic lesions of styrene in the Japanese Medaka (Oryzias latipes) were compared with those of styrene oxide, the active metabolite of styrene, using embryo-larval assays. The developmental stages of Japanese Medaka (Oryzias latipes) treated with both chemicals were not altered and progressed normally. However, styrene oxide was more toxic than styrene in terms of causing death and lesions . High concentrations of styrene (higher than 4.9 ppm) and styrene oxide (higher than 2.4 ppm), resulting in more than 50% mortality, caused similar lesions of cardiovascular system, craniofacial bone formation and spinal deformities, although a number of lesions were not observed by both chemicals . In the group treated with styrene, eyeball sizes and intereye distances were reduced, while, in the group treated with styrene oxide , the eyes and eye cups were not developed and two eyes were sometimes fused. In addition, styrene oxide caused the lesion which involved the posterior brain and brain stem were herniated through the spinal cord . The noticeable difference of toxic symptoms between these two chemicals was the time of onset. Toxicities of cardiovascular system and craniofacial bone formation appeared on day 3 of development in styrene oxide treated group, but, styrene treated group staned to show hemorrhages on day 3 and the craniofacial malformation were appeared on day 5, These differences between two chemicals may be due to the metabolism of styrene to styrene oxide, the reactive intermediate.

• Environmental Analysis Health and Toxicology
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• 제30권
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• pp.6.1-6.7
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• 2015

Objectives This study aimed to estimate the effects of 4-nonylphenol (NP), a ubiquitously present surfactant in aquatic environments, on the anti-oxidant systems of the liver in the Far Eastern catfish Silurus asotus. Methods Changes in biochemical parameters involved in glutathione (GSH)-related and other anti-oxidant systems were analyzed following 4 weeks of 4-NP administration (0.1 and 1.0 mg/kg diet) via a formulated diet to catfish. Results 4-NP exposure induced an elevation in hepatic lipid peroxide levels and an accompanying decrease in reduced state GSH after 2 weeks, suggesting pro-oxidant effects of the chemical in catfish. This oxidative stress was associated with an inhibition of the GSH-utilizing enzyme glutathione peroxidase at the same time point. This inhibition was restored after 4 weeks. The activities of other anti-oxidant enzymes, i.e., glutathione reductase, superoxide dismutase and catalase were increased after 4 weeks. These enzyme increases occurred more strongly at the higher 4-NP concentration (1.0 mg/kg diet). Conclusions 4-NP given to catfish at 0.1 to 1.0 mg/kg diet, concentrations relevant to environmental levels, depletes the endogenous anti-oxidant molecule GSH and temporarily inhibits GSH-related anti-oxidant enzymes. Such declines in anti-oxidant capacity and elevated oxidative stress seem to be compensated eventually by subsequent activation of various anti-oxidant enzyme systems.

• 셀메드
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• 제4권3호
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• pp.15.1-15.14
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• 2014

Andrographis paniculata (Burm. F.) Wall. Ex Nees (Family: Anthaceae) is a traditionally known Ayurvedic medicinal plant. Several well-controlled clinical trials conducted during recent years have consistently reconfirmed that Andrographis paniculata extracts are effective in suppressing cardinal symptoms of diverse inflammatory and infectious diseases. Despite extensive efforts though, many questions concerning bioactive constituents of such extracts and their modes of actions still remain unanswered. Amongst diverse diterpene lactones isolated to date from such extracts, andrographolide is often considered to be the major, representative, or bioactive secondary metabolite of the plant. Therefore, it has attracted considerable attention of several drug discovery laboratories as a lead molecule potentially useful for identifying structurally and functionally novel drug. Critical analysis of available preclinical and clinical information on Andrographis paniculata extracts and pure andrographolide strongly suggest that they are pharmacologically polyvalent and that they possess adaptogenic properties. Aim of this communication is to summarize and critically analyze such data, and to point out some possibilities for more rationally exploiting their adaptogenic properties for discovering novel therapeutic leads, or for obtaining pharmacologically better standardized phyto-pharmaceuticals.

• Journal of Microbiology and Biotechnology
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• 제16권5호
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• pp.764-770
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• 2006

Dihydrochalcomycin (GERI-155), produced by Streptomyces sp. KCTC-0041BP isolated from Korean soil, is a 16-membered macrolide antibiotic consisting of two deoxysugar moieties at C-5 and C-20 positions of a branched lactone ring. The cloning and sequencing of a gene cluster for dihydrochalcomycin biosynthesis revealed a 63-kb nucleotide region containing 25 open reading frames (ORFs). The products of all of these 25 ORFs playa role in dihydrochalcomycin biosynthesis and self-resistance against the compounds synthesized. At the core of this cluster lies a 39.6-kb polyketide synthase (PKS) region encoding eight modules in five giant multifunctional protein-coding genes (gerSI-SV). The genes responsible for the biosynthesis of deoxysugar moieties, D-chalcose and D-mycinose, and their modification and attachment were found on either side of this PKS region. The involvement of this gene cluster in dihydrochalcomycin biosynthesis was confirmed by disruption of the dehydratase (DH) domain in module 3 of the PKS gene and by metabolite analysis.

• Environmental Analysis Health and Toxicology
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• 제3권3_4호
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• pp.39-51
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• 1988

Effects of ${\alpha}$-tocopherol and perilla oil on the toxicity of polychlorinated biphenyls (PCB) in male rat were studied. Rats were fed ad libitum for 6 weeks with the animal diet which contains PCB 30 ppm and 100 ppm. Perilla oil (0.5 g/kg body weight) and ${\alpha}$-tocopherol (30 mg/kg body weight) were administered intraperitoneally twice a week for 6 weeks. Rats fed with PCB showed enlargement of liver and spleen, increase in aspartate aminotransferase, alkaline phosphatase, sereum lipid and cytochrome P 450 and decrease in body weight and glutathione. When perilla oil was administered to rats fed with PCB increase in aspartate aminotransferase, alkaline phosphatase, serum lipid and cytochrome P45O and decrease in body weight and glutathione were significantly augmented, compared to rats fed with PCB alone. This means that perilla oil potentiates the toxicity of PCB. On the other hand when ${\alpha}$-tocopherol was administered to rats fed with PCB increase in aspartate aminotransferase, alkaline phosphatase, serum lipid and cytochrome P45O and decrease in body weight and glutathione were signigicantly reduced, compared to rats fed with PCB alone. This means that u-tocopherol reduces the toxicity of PCB. From the above results, it may be concluded that PCB is metabolized by microsomal mixed function oxidase and the metabolite causes the toxicity and microsomal glutathione plays a role of protection on the toxicity of PCB.

• Clinical and Experimental Pediatrics
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• 제55권2호
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• pp.35-41
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• 2012

Passive exposure to tobacco smoke significantly contributes to morbidity and mortality in children. Children, in particular, seem to be the most susceptible population to the harmful effects of environmental tobacco smoke (ETS). Paternal smoking inside the home leads to significant maternal and fetal exposure to ETS and may subsequently affect fetal health. ETS has been associated with adverse effects on pediatric health, including preterm birth, intrauterine growth retardation, perinatal mortality, respiratory illness, neurobehavioral problems, and decreased performance in school. A valid estimation of the risks associated with tobacco exposure depends on accurate measurement. Nicotine and its major metabolite, cotinine, are commonly used as smoking biomarkers, and their levels can be determined in various biological specimens such as blood, saliva, and urine. Recently, hair analysis was found to be a convenient, noninvasive technique for detecting the presence of nicotine exposure. Because nicotine/cotinine accumulates in hair during hair growth, it is a unique measure of longterm, cumulative exposure to tobacco smoke. Although smoking ban policies result in considerable reductions in ETS exposure, children are still exposed significantly to tobacco smoke not only in their homes but also in schools, restaurants, child-care settings, cars, buses, and other public places. Therefore, more effective strategies and public policies to protect preschool children from ETS should be consolidated.

• 한국미생물·생명공학회지
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• 제17권6호
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• pp.552-555
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• 1989

Corynebacterium glutamicum의 NADPH-specific glutamate dehydrogenase를 이용하여 NADPH, NH$_4$Cl, $\alpha$-ketoglutarate의 기질에 대한 kinetics를 고찰하였다. 이들의 kinetic constants를 측정함으로서 정반응에로의 효소반응 기작은 첫번째 효소와 반응하는 기질이 NADPH 임을 확인할 수 있었다. Glutamate dehydrogenase 활성의 조절을 위한 metabolites의 효과를 고찰하여 본 결과 malate와 citrate 만이 효소에 억제 효과를 나타내었으며, potassium chloride는 효소활성에 가장 많은 영향을 주었다.

• The Plant Pathology Journal
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• 제34권3호
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• pp.250-255
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• 2018

Pine wilt disease, caused by the nematode Bursaphelenchus xylophilus, is one of the most devastating conifer diseases decimating several species of pine trees on a global scale. Here, we report the draft genome of Raoultella ornithinolytica MG, which is isolated from mountain-cultivated ginseng plant as an bacterial endophyte and shows nematicidal activity against B. xylophilus. Our analysis of R. ornithinolytica MG genome showed that it possesses many genes encoding potential nematicidal factors in addition to some secondary metabolite biosynthetic gene clusters that may contribute to the observed nematicidal activity of the strain. Furthermore, the genome was lacking key components of avermectin gene cluster, suggesting that nematicidal activity of the bacterium is not likely due to the famous anthelmintic agent of wide-spread use, avermectin. This genomic information of R. ornithinolytica will provide basis for identification and engineering of genes and their products toward control of pine wilt disease.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2002년도 추계학술대회
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• pp.27-30
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• 2002

Ralstonia eutrupha JMP134 is a well-known soil bacterium which can metabolite diverse aromatic compounds and xenobiotics, such as phenol, 2,4-dichlorophenoxy acetic acid (2, 4-D), and trichloroethylene (TCE), etc. Phenol is degraded through chromosomally encoded phenol degradation pathway. Phenol is first metabolized into catechol by a multicomponent phenol hydroxylase, which is further metabolized to TCA cycle intermediates via a meta-cleavage pathway. The nucleotide sequences of the genes for the phenol hydroxylase have previously been determined, and found to composed of eight genes phlKLMNOPRX in an operon structure. The phlR, whose gene product is a NtrC-like transcriptional activator, was found to be located at the internal region of the structural genes, which is not the case in most bacteria where the regulatory genes lie near the structural genes. In addition to this regulatory gene, we found other regulatory genes, the phlA and phlR2, downstream of the phlX. These genes were found to be overlapped and hence likely to be co-transcribed. The protein similarity analysis has revealed that the PhlA belongs to the GntR family, which are known to be negative regulators, whereas the PhlR2 shares high homology with the NtrC-type family of transcriptional activators like the PhlR. Disruption of the phlA by insertional mutation has led to the constitutive expression of the activity of phenol hydroxylase in JMP134, indicating that PhlA is a negative regulator. Possible regulatory mechanisms of phenol metabolism in R. eutropha JMP134 has been discussed.