• Journal of Microbiology and Biotechnology
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• 제20권4호
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• pp.789-797
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• 2010

The limited information on differential gene expression in the different serotypes of Actinobacillus pleuropneumoniae has significantly hampered the research on the pathogenic mechanisms of this organism and the development of multivalent vaccines against A. pleuropneumoniae infection. To compare the gene expressions in the A. pleuropneumoniae strains CVCC259 (serotype 1) and CVCC261 (serotype 3), we screened the differentially expressed genes in the two strains by performing representational difference analysis (RDA). Northern blot analyses were used to confirm the results of RDA. We identified 22 differentially expressed genes in the CVCC259 strain and 20 differentially expressed genes in the CVCC261 strain, and these genes were classified into 11 groups: (1) genes encoding APX toxins; (2) genes encoding transferrin-binding protein; (3) genes involved in lipopolysaccharide (LPS) biosynthesis; (4) genes encoding autotransporter adhesin; (5) genes involved in metabolism; (6) genes involved in the ATP-binding cassette (ABC) transporter system; (7) genes encoding molecular chaperones; (8) genes involved in bacterial transcription and nucleic acid metabolism; (9) a gene encoding protease; (10) genes encoding lipoprotein/membrane protein; and (11) genes encoding various hypothetical proteins. This is the first report on the systematic application of RDA for the analysis of differential gene expression in A. pleuropneumoniae serotypes 1 and 3. The determination of these differentially expressed genes will serve as an indicator for future research on the pathogenic mechanisms of A. pleuropneumoniae and the development of a multivalent vaccine against A. pleuropneumoniae infection.

• 한국수산과학회지
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• 제7권1호
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• pp.28-36
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• 1974

꽂게 (Portunus trituberculatus) 240미, 민꽂게(Charybdis japonica) 78미 등을 2월 21일 부터 8월 7일 까지 사육하면서, 이들이 먹이를 먹을 때 내는 소리를 녹음실의 간이 수조속에서 녹음하고, 행동을 관찰하였으며, 녹음된 소리를 증폭시켜 무향 수조 속에서 수중 스피커로 방성하였을 때, 수조속 꽃게들의 반응결과와 녹음된 소리를 분석한 결과를 요약하면 다음과 같다. 1. 꽃게들이 내는 소리의 음압은 크기별, 군별로 다르며, $52\~124db$이고, 주파수는 $250\~1000Hz$이다. 2. 꽃게의 내는 소리를 방성할때 추음효과는 약 $70\%$이다. 3. 꽃게의 추음속도는 $3\~6cm/sec$이며, 스피커에 도달한 게는 그곳을 떠나지 않는다. 4, 꽃게의 소리를 이용하여 음향어법에 적용할 때 꽃게의 크기는 갑장 $5.6\~6.5Cm$, 갑폭 $12.6\~15cm$인 암컷이 적당하다.

• 한국환경보건학회지
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• 제35권5호
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• pp.386-392
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• 2009

This study was undertaken to compare the performance of three dust samplers for collecting cotton dust fibers. For this study, three dust samplers including Vertical Elutriator (VE), Total Dust Method (TDM) using 37 mm cassette, and the Institute of Occupational Medicine (IOM) sampler were selected. A total of 6 cotton mills and 4 towel factories were investigated. When measured by VE, the GM for cotton dust was 0.19 $mg/m^3$ which was less than the current occupational exposure limit (OEL) 0.2 $mg/m^3$. But when measured by TDM and IOM at the same locations, the GMs were 0.37 and 0.63 $mg/m^3$, respectively. In Korea, most industrial hygienists have used the TDM for cotton dust measurements and the results were compared with either the TLV for cotton dust or the PNOC (particulates not otherwise classified) of 10 $mg/m^3$ for making decisions. The results of this study clearly showed that past cotton dust measurements and decisions made with such results were not correct. It needs to be noticed the related contents by using VE if it applies to the exposure limit, 0.2 $mg/m^3$, and needs to be revised the exposure limit by IOM. Also, if TDM is used, it requires to be studied and suggested to the new OEL.

• BMB Reports
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• 제38권1호
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• pp.41-48
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• 2005

In this study we developed the transposon-mediated shuttle vector 'Hanpvid', which composed of HaNPV (Heliothis armigera nuclear polyhedrosis virus) genomic DNA and a transposon cassette from Bacmid of Bac-to-Bac system. Hanpvid replicates in E. coli in the same way as Bacmid and retains infective function in cotton bollworm cells (Hz-AM1). Using Hanpvid we constructed a recombinant virus, which could infect Hz-AM1 cells and generate recombinant HaNPV (rHa-Bar) containing the barnase gene, a ribonuclease gene from Bacillus amyloliquefaciens. Since the expression vector carrying barnase gene cannot replicate in the absence of barstar, a specific inhibitor of barnase, we constructed a new cotton bollworm cell line (AM1-NB) using the marker rescue method. In AM1-NB barstar was integrated into the cellular chromosome to sustain the replication of rHa-Bar. To screen out recombinant HaNPV for potential use as biopesticide, Hz-AM1 and AM1-NB cell lines were infected with rHa-Bar, respectively. The results obtained indicate that Viral progenies in AM1-NB were 23 and 160 times greater than those in Hz-AM1 48 h and 72 h after infection, respectively. With additional insertion of the polyhedron gene from AcNPV (Autographa californica nuclear polyhedrosis virus) into the Hanpvid genome, rHa-Bar regained the polyhedron phenotype and its pest-killing rate greatly improved. Toxic analysis showed that the lethal dosages ($LD_{50}$) and the lethal time(s) ($LT_{50}$) of rHa-Bar were reduced by 20% and 30%, respectively, compared to wt-HaNPV in the third instar larvae of cotton bollworm. This study shows that in AM1-NB barnase can be effectively produced and used as pest-killing agent for the biological control of cotton pests.

• 한국산업보건학회지
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• 제23권2호
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• pp.75-83
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• 2013

Objectives: This study was conducted to estimate quartz concentrations in the airborne respirable dust from concrete manufacturing industries and to compare performance of two analytical methods, direct on filter(DOF) and the transfer methods in the Fourier Transform Infrared Spectroscopy(FTIR). Methods: Total 36 area samples were collected from 8 concrete manufacturing industries. Each respirable dust sample was collected by a 25 mm cassette attached to a 10 mm Dorr-Oliver nylon cyclone. The quartz content was estimated using the intensity of the absorption peak of quartz at $799cm^{-1}$ by FTIR. Results: By the comparison of quartz content in respirable dust between the two methods, the results of using DOF method were higher than that of transfer method. And the result of quartz concentrations in respirable dust estimated by DOF method were mostly higher than those by transfer method. Statistically significant difference of quartz concentrations in respirable dust were not found in shakeout, input, loading and transporting processes by two methods. But quartz concentrations in the molding process had the statistically significant difference between DOF and transfer method. Conclusions: The results of the study is suggested that, it be needed to correct the influence of the interferences in order to establish the DOF method when interfering minerals have an effect on quantitative analysis of quartz in respirable dust by the direct on filter method with FTIR.

• ALGAE
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• 제27권4호
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• pp.295-301
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• 2012

Carbon concentrating mechanisms play a vital role in photosynthesis in microalgae and cyanobacteria especially in the proper functioning of Rubisco and assimilation of carbon via the Calvin cycle. This study evaluates the role of carbon dioxide on carbon concentrating mechanism (CCM) in a cynaobacteria, Spirulina platensis and a microalga, Chlorella sp. 786. The study organisms were grown in both atmospheric (control sample, 0.035%) and high (exposed sample, 10%) $CO_2$ concentrations. Second dimension (2D) electrophoresis revealed a huge difference in the protein profiles of both organisms suggesting the induction of CCM related proteins in the sample maintained at atmospheric $CO_2$ concentration and the repression of CCM related proteins in the sample maintained at 10% $CO_2$. Liquid chromatography-mass spectroscopy analysis revealed the presence of two important $C_i$ transporter proteins in the control sample of S. platensis, namely ferredoxin-$NADP^+$ reductase and ATP binding cassette (ABC) transport system protein. These proteins were only expressed in the control sample and were downregulated or not expressed at all in the exposed sample. Consequently, this study conclusively proves that CCMs are only inducted at low $CO_2$ concentrations and are not functional at high $CO_2$ concentration.

• 한국발생생물학회지:발생과생식
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• 제14권1호
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• pp.13-19
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• 2010

We developed a novel dicistronic system for the expression of target cDNA sequences in the milk of transgenic animals using goat beta-casein/hGH fusion construct, pGbc5.5hGH (Lee, 2006) and internal ribosome entry site (IRES) sequences of encephalomyocarditis virus (EMCV). Granulocyte colony-stimulating factor (hG-CSF) cDNA was linked to 3' untranslated region of hGH gene in the pGbc5.5hGH via EMCV IRES sequences. Transgenic mice were generated by microinjection and transgene expression was examined in the milk and mammary gland of transgenic mice at 10 days of lactation. Northern blot analysis showed that hGH gene and hG-CSF cDNA were transcribed as a single dicistronic mRNA. The hG-CSF and hGH proteins were independently translated from the dicistronic mRNA and secreted into the milk of transgenic mice. The highest concentration of hG-CSF and hGH in the milk of transgenic mice were $237{\mu}g/m{\ell}$ and $8,990{\mu}g/m{\ell}$, respectively. In contrast, another hG-CSF expression cassette, in which hG-CSF genomic sequences were inserted into a commercial milk-specific expression vector (pBC1), generated a lower level ($91{\mu}g/m{\ell}$) of hG-CSF expression in the milk of transgenic mice. These results demonstrated that the novel pGbc5.5hGH-based dicistronic construct could be useful for an efficient cDNA expression in the milk of transgenic animals.

• Journal of Microbiology and Biotechnology
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• 제22권8호
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• pp.1133-1140
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• 2012

Ribonucleic acid interference (RNAi) inhibits the expression of target genes in a sequence-specific manner, and shows potential for gene knockdown in filamentous fungi, in which the locus-specific gene knockout occurs in low frequency. In this study, the function of the repressor of cellulase expression I (ACEI) was verified in Trichoderma koningii (T. koningii) YC01 through RNAi, and ace1-silenced strains with improved cellulase productivity were obtained. An expression cassette that transcribed the interfering double-stranded RNA (dsRNA) of ace1 was constructed and transformed into T. koningii, and the transformants, in which the expression of ace1 was successfully silenced, were selected. As a result of the ace1 gene silencing, the expression levels of the main cellulase and xylanase genes were elevated, and the enhanced production of total proteins, cellulase, and xylanase was observed in the cultivation. In addition, the down-regulation of ace1 resulted in an increasing expression of xyr1, but no clear variation in the expression of cre1, which suggested that ACEI acted as a repressor of the xyr1 transcription, but was not involved in the regulation of the cre1 expression. The results of this work indicate that ace1 is a valid target gene for enhancing enzyme production in T. koningii, and RNAi is an appropriate tool for improving the properties of industrial fungi.

• Journal of Microbiology and Biotechnology
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• 제19권5호
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• pp.439-446
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• 2009

The biosynthesis study of antibiotics saframycin (SFM) in Streptomyces lavendulae and safracin (SAC) in Pseudomonas fluorescens demonstrated that 3-hydroxy-S-methyl-O-methyltyrosine (3hSmOmTyr), a nonproteinogenic amino acid, is the precursor of the tetrahydroisoquinoline molecular core. In the biosynthetic gene cluster of SAC/SFM, sacD/sfmD encodes a protein with high homology to each other but no sequence similarity to other known enzymes; sacF/sfmM2 and sacG/sfmM3 encode methyltransferases for C-methylation and O-methylation; and sacE/sfinF encodes a small protein with significant sequence similarity to the MbtH-like proteins, which are frequently found in the biosynthetic pathways of non ribosomal peptide antibiotics and siderophores. To address their function, the biosynthetic cassette of 3h5mOmTyr was heterologously expressed in S. coelicolor and P. putida, and an in-frame deletion and complementation in trans were carried out. The results revealed that (i) SfmD catalyzes the hydroxylation of aromatic rings; (ii) sacD/sacF/sacG in the SAC gene cluster and sfmD/sfmM2/sfmM3 in the SFM cluster are sufficient for the biosynthesis of 3h5mOmTyr; and (iii) the mbtH-like gene is not required for the biosynthesis of the 3h5mOmTyr precursor.

• 한국미생물·생명공학회지
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• 제44권4호
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• pp.563-570
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• 2016

S. griseus wild type에서 dasA 유전자의 과발현에 의해 유도된 기저균사의 ectopic sporulation 관련 유전자를 알아보기 위해서, empty vector가 삽입된 균주와 dasA가 과발현된 균주의 전사체를 DNA microarray법으로 비교하였다. DNA microarray 결과를 토대로 dasA 유전자 과발현 균주에서 2배이상 발현량이 증가되었으며 p-value가 0.05 미만(p-value < 0.05)인 유전자들 중에서 false positive 를 제외시키는 작업을 통하여 최종적으로 4개의 유전자(SGR794, SGR2469, SGR3656, SGR3657)와 3개의 cluster (SGR795-797, SGR2377-2378, SGR6997-6998)를 선발하였다. 이들의 전사량은 low resolution Sl nuclease mapping 법을 통하여 dasA 유전자 과발현 균주에서 증가된 것을 확인하였다.