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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
The Korean Journal of Microbiology
Journal Basic Information
Journal DOI :
The Microbiological Society of Korea
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Volume & Issues
Volume 47, Issue 4 - Dec 2011
Volume 47, Issue 3 - Sep 2011
Volume 47, Issue 2 - Jun 2011
Volume 47, Issue 1 - Mar 2011
Selecting the target year
Development of the Gene Therapy Vector for Targeting Ovarian Cancer Cells through ErbB Receptors
Joung, In-Sil ; Bang, Seong-Ho ;
The Korean Journal of Microbiology, volume 47, issue 1, 2011, Pages 1~6
Inefficiency of in vivo gene transfer using currently available vectors reflects a major hurdle in cancer gene therapy. Both viral and non-viral approaches have been described to improve gene transfer efficiency but suffer from a number of limitations. Here we tested an adenovirus carrying the small peptide ligand derived from heregulin
EGF-like domain onto fiber, the adenoviral capsid protein, to deliver transgene to ovarian cancer cells which overexpress ErbB, the cognate receptors for heregulin. The attachement of 53 amino acids to fiber didn't affect on the fiber's trimer structure that is critical for the viral entry to cells. The fiber-modified adenovirus can mediate entry and expression of a
-galactosidase into cancer cells in an increased efficiency compared the unmodified adenovirus. Particularly, the gene transfer efficiency was improved up to 5 times in OVCAR3 cells, an ovarian cancer cell line. Such transduction systems hold promise for delivering genes to ErbB receptor overexpressing cancer cells, and could be used for future cancer gene therapy.
Analysis of Toxicity in Escherichia coli from the Expression of Human Purinergic Receptor
Yu, Yon-Joo ; Jung, Yun-A ; Lim, Dong-Bin ;
The Korean Journal of Microbiology, volume 47, issue 1, 2011, Pages 7~13
In general, expression of membrane protein in Escherichia coli is very toxic to the host organism, but the mechanism for the toxicity is not clear yet. Expression of human purinergic receptor
was found to be extremely toxic to the host E. coli. We examined this toxicity by isolation and analysis of less toxic mutant proteins. We could isolate 30 less toxic mutants of
after hydroxylamine mutagenesis. Western blot showed that all of them produced proteins smaller than the wild type
. DNA sequencing of two largest mutant proteins showed that they were lost its second transmembrane domain. Localization analysis of these mutant proteins showed that they are not in cytoplasmic membrane, but in inclusion bodies. These data showed that inactive truncated
is not toxic to E. coli and membrane integration and functionality of
may be needed to show host toxicity.
Spectrofluorometric Characteristics of the N-Terminal Domain of Riboflavin Synthase
Kim, Ryu-Ryun ; Yi, Jeong-Hwan ; Nam, Ki-Seok ; Ko, Kyung-Won ; Lee, Chan-Yong ;
The Korean Journal of Microbiology, volume 47, issue 1, 2011, Pages 14~21
Riboflavin synthase catalyzes the formation of one molecule of each riboflavin and 5-amino-6-ribitylamino-2,4-pyrimidinedione by the transfer of a 4-carbon moiety between two molecules of the substrates, 6,7-dimetyl-8-ribityllumazine. The most remarkable feature is the sequence similarity between the N-terminal half (1-97) and the C-terminal half domain (99-213). To investigate the structure and fluorescent characteristics of the N-terminal half of riboflavin synthase (N-RS) in Escherichia coli, more than 10 mutant genes coding for the mutated N-terminal domain of riboflavin synthase were generated by polymerase chain reaction. The genes coding for the proteins were inserted into pQE vector designed for easy purification of protein by 6X-His tagging system, expressed, and the proteins were purified. Almost all mutated N-terminal domain of riboflavin synthases bind to 6,7-dimethyl-8-ribityllumazine and riboflavin as fluorescent ligands. However, N-RS C47D and N-RS ET66,67DQ mutant proteins show colorless, indicating that fluorescent ligands were dissociated during purification. In addition, most mutated proteins show low fluorescent intensity comparing to N-RS wild type, whereas N-RS C48S posses stronger fluorescent intensity than that of wild type protein. Based on this result, N-RS C48S can be used as the tool for high throughput screening system for searching for the compound with inhibitory effect for the riboflavin synthase.
Photochemical/Biophysical Properties of Proteorhodopsin and Anabaena Sensory Rhodopsin in Various Physical Environments
Choi, Ah-Reum ; Han, Song-I ; Chung, Young-Ho ; Jung, Kwang-Hwan ;
The Korean Journal of Microbiology, volume 47, issue 1, 2011, Pages 22~29
Rhodopsin is a membrane protein with seven transmembrane region which contains a retinal as its chromophore. Although there have been recently reports on various photo-biochemical features of rhodopsins by a wide range of purifying and measurement methods, there was no actual comparison related to the difference of biochemical characteristics according to their physical environment of rhodopsins. First, proteorhodopsin (PR) was found in marine proteobacteria whose function is known for pumping proton using light energy. Second one is Anabaena sensory rhodopsin (Nostoc sp.) PCC7120 (ASR) which belongs to eubacteria acts as sensory regulator since it is co-expressed with transducer 14 kDa in an operon. In this study, we applied two types of rhodopsins (PR and ASR) to various environmental conditions such as in Escherichia coli membranes, membrane in acrylamide gel, in DDM (n-dodecyl-
-D-maltopyranoside), OG (octyl-
-D-glucopyranoside), and reconstituted with DOPC (1,2-didecanoyl-sn-glycero-3-phosphocholine). According to the light-induced difference spectroscopy, rhodopsins in 0.02% DDM clearly showed photointermediates like M, and O states which respond to the different wavelengths, respectively and showed the best signal/noise ratio. The laser-induced difference spectra showed the fast formation and decay rate of photointermediates in the DDM solubilized samples than gel encapsulated rhodopsin. Each of rhodopsins seemed to be adapted to its surrounding environment.
Early Diagnostic Method of Avian Influenza Virus Subtype Using Ultra Real-Time PCR
Kim, Sang-Tae ; Kim, Young-Kyoon ; Kim, Jang-Su ;
The Korean Journal of Microbiology, volume 47, issue 1, 2011, Pages 30~37
This ultra real-time PCR (UPCR) based diagnosis system for avian influenza A virus (AIV) subtype was designed. The target primer in this study was derived from H5N1 subtype-specific 133 bp partial gene of hemagglutinin (HA), and was synthesized by using PCR-based gene synthesis on the ground of safety. UPCR was operated by Mini-Opticon Q-PCR Quantitative Thermal Cycler using aptamer-based molecular beacon, total 10
of reaction mixture with extraordinarily short time in each steps in PCR. The detection including UPCR and analysis of melting temperature was totally operated within 15 min. The AIV-specific 133 bp PCR product was correctly amplified until 5 molecules of HA gene as minimum of templates. This kind of PCR was drafted as UPCR in this study and it could be used to detect not only AIV subtype, but also other pathogens using UPCR-based diagnosis.
Distribution and Characteristics of Culturable Airborne Bacteria and Fungi in Municipal Wastewater Treatment Plants
Park, Kyo-Nam ; Koh, Ji-Yun ; Jeong, Choon-Soo ; Kim, Jong-Seol ;
The Korean Journal of Microbiology, volume 47, issue 1, 2011, Pages 38~49
Bioaerosols generated from wastewater treatment plants may create health risks for plant workers and nearby residents. To determine the levels of culturable airborne bacteria and fungi in bioaerosols, samples were seasonally collected above and near the aeration tanks of one feces-urine and three sewage treatment plants in Ulsan, Korea with an impaction-type sampler. In the feces-urine treatment plant, concentrations of heterotrophic bacteria were between
above the aeration tank and between
near the aeration tank. Coliform bacteria were detected both above and near the aeration tank. In cases of sewage treatment plant, the numbers of heterotrophic bacteria ranged from
above the aeration tank and from
near the aeration tank. At reference sites, the concentrations of heterotrophs in ambient air were measured between
. When we isolated and tentatively identified heterotrophic bacteria, Pseudomonas luteola was the most dominant species in bioaerosols from wastewater treatment plants, whereas the most abundant one in reference samples was Micrococcus sp. When we measured fungal concentrations in bioaerosols, they were rather similar regardless of sampling locations and seasons, and such genera as Cladosporium, Alternaria, and Penicillium were commonly identified.
A Rapid Method for Monitoring of Gram-positive Bacteria in Wastewater Treatment Systems
Nam, Ji-Hyun ; Bae, Woo-Keun ; Lee, Dong-Hun ;
The Korean Journal of Microbiology, volume 47, issue 1, 2011, Pages 50~55
A simple and rapid method was developed for monitoring of Gram-positive bacteria in the wastewater treatment system. Culture suspensions of 4 Gram-positive and 4 Gram-negative strains were filtrated and stained with a polyethersulfone membrane filter and Toluidine Blue-O. To establish quantitative color image analysis, the intensity value of RGB (red-green-blue) color of a scanned filter image was analyzed with a photographic program. Red and green color values of Gram-positive bacteria were higher than those of Gram-negative bacteria. This method was applied to the activated sludge mixed with the Gram-positive bacteria. Although evaluation was difficult due to the irregular size and shape of flocs, the population of Gram-positive bacteria in the activated sludge could be monitored with floc dispersion technique. The more amounts of Gram-positive bacteria in the activated sludge led to the increase of red and green color values. This method provides a rapid and quantitative measurement of Gram-positive bacteria within the wastewater treatment systems.
The Bacterial Community Structure in Biofilms of the RABC Process for Swine Butchery Wastewater Treatment
Sung, Gi-Moon ; Lee, Dong-Geun ; Park, Seong-Joo ;
The Korean Journal of Microbiology, volume 47, issue 1, 2011, Pages 56~65
Culture-independent microscopic observations and 16S rDNA analyses were applied to describe the bacterial community inherent to the biofilm structure of the RABC (Rotating Activated Bacillus Contactors) process for swine butchery wastewater treatment. The ratios of Gram-positive bacterial counts to total bacterial counts of the RABC process were significantly increased in the last aeration tank as well as returned sludge, while those of the existing A2O (Anaerobic-Anoxic-Oxic) process maintained constant from aeration tanks to returned sludge. Totally nine phyla were recovered by 16S rDNA analysis, two of which were major groups: the Proteobacteria (64.1%) and the Actinobacteria (18.4%). The third major group was the endospore-forming Firmicutes (5.4%). The remaining six minor groups are the Bacteroidetes (3.3%), the Chlorobi (2.2%), the Nitrospirae (1.1%), the Chlorofleix (1.1%), the Acidobacteria (1.1%), and the Fusobacteria (1.1%). The ratio of endospore-forming bacteria was 19.4%, which was composed of the members of the Firmicutes phylum (5.4%) and the Intrasporangiaceae family (14.0%) of the Actinobacteria phylum. Nitrifying and denitrifying related- and phosphorus accumulating related-sequences were composed of 6.5% and 5.4% of total community, respectively, these could mean the high capacity of the RABC process to remove odor compounds and reduce eutrophication by efficient removing inorganic nutrients.
Biodiversity and Isolation of Gut Microbes from Digestive Organs of Harmonia axyridis
Kim, Ki-Kwang ; Han, Song-Ih ; Moon, Chung-Won ; Yu, Yong-Man ; Whang, Kyung-Sook ;
The Korean Journal of Microbiology, volume 47, issue 1, 2011, Pages 66~73
Bacterial density distributions of gut microbes in the digestive organs of Harmonia axyridis collected from three different sources (JK, CK, and CJ) were
CFU/gut under aerobic culture condition and
CFU/gut under anaerobic culture condition. Seven colony types were observed under aerobic condition and three types of similarity were detected under anaerobic condition. In total, 116 strains, including 34 strains under aerobic condition, were isolated from the digestive organs of H. axyridis. Based on the analysis of the 16S rRNA gene sequence, aerobic gut microbes were assigned to the Proteobacteria, Actinobacteria, Firmicutes, and Deinococcus-Thermus. A large number of isolates belonged to the genus Bacillus and Staphylococcus of the Firmicutes commonly found in H. axyridis from different sites. Anaerobic gut microbes were found to be similar according to colony morphological, phylogenetic analysis using ARDRA. Eighty-two anaerobic gut microbes were clustered into 17 different ARDRA types according to HaeIII. Representative anaerobic gut microbes in each ARDRA group were divided into five species of
-Proteobacteria based on 16S rRNA gene sequence analysis; Hafnia alvei, Enterobacter ludwigii, Enterobacter kobei, Pseudomonas oryzihabitans and Pseudomonas koreensis. Phylogenetic analysis indicated that about 70% of the isolates belonged to
-Proteobacteria, suggesting predominance of gut microbes.
Characteristics of Bacteriocin Produced by Lactococcus lactis ET45 Isolated from Kimchi
Jeong, Seong-Yeop ; Park, Chan-Sun ; Choi, Nack-Shick ; Yang, Hee-Jong ; Kim, Cha-Young ; Yoon, Byoung-Dae ; Kang, Dae-Ook ; Ryu, Yeon-Woo ; Kim, Min-Soo ;
The Korean Journal of Microbiology, volume 47, issue 1, 2011, Pages 74~80
Bacteriocin-producing lactic acid bacterium having antagonistic activity against Bacillus cereus, was isolated from Kimchi. The selected strain was identified as Lactococcus lactis by the Bergey's manual and 16S rDNA analysis, and named as L. lactis ET45. The bacteriocin was stable in the pH range 3.0-11.0. The bacteriocin was active over a wide temperature range from
. Optimal culture condition for producing bacteriocin was obtained by growing the cells on MRS medium at pH 7.5 and
for 18 h. Antibacterial activity of the bacteriocin was completely disappeared by proteinase K, and this means that bacteriocin is a proteinous substance. The molecular weight of bacteriocin was estimated to be about 4.5 kDa by tricine sodium dodecyl sulfate polyacryamide gel electrophoresis (TSDS-PAGE).
Characterization of Extracellular Xylanase from Paenibacillus donghaensis JH8
Lim, Chae-Sung ; Oh, Yong-Sik ; Roh, Dong-Hyun ;
The Korean Journal of Microbiology, volume 47, issue 1, 2011, Pages 81~86
Xylanase is a class of enzymes that hydrolyze the linear polysaccharide
-1,4-xylan into xylose. This enzyme is applied in the process of paper making and may be used for the process of biofuel production in the future. The Paenibacillus donghaensis JH8, isolated from Donghae deepsea sediment and reported as a novel bacterium, was known to degrade xylan and its xylanase was characterized in this study. The enzyme was maximally induced in the presence of 0.1% xylan. The production of xylanase was started at early logarithmic phase and reached about 55 miliunit at stationary phase of growth. The optimal temperature and pH of extracellular xylanase were found to be
and pH 6.0, respectively. The activity of xylanase was inhibited by the presence of
or EDTA, and activated by
or DTT. This xylanase was stable at
for 120 min, but lost almost their activity in 30 min at
. Zymography analysis of concentrated culture supernatant revealed one major band at 42 kDa and two faint bands at 68 and 120 kDa.
Comparison of Real-Time PCR and Conventional Culture Method for Detection of Cronobacter spp. in Powdered Foods
Chon, Jung-Whan ; Song, Kwang-Young ; Kim, Sun-Young ; Hyeon, Ji-Yeon ; Kim, Yun-Gyeong ; Hwang, In-Gyun ; Kwak, Hyo-Sun ; Seo, Kun-Ho ;
The Korean Journal of Microbiology, volume 47, issue 1, 2011, Pages 87~91
The aim of this study was to compare the performance of conventional culture and real-time PCR for detection of Cronobacter spp. in powdered foods. Infant formula, baby food and Misugaru inoculated with Cronobacter were enriched in distilled water as first enrichment step, followed by incubating in Enterobacteriaceae enrichment (EE) broth as second enrichment step. A loopful of enriched sample was streaked onto Druggan-Forsythe-Iversen agar, followed by incubating at
for 24 h. One milliliter of the enriched distilled water and EE broth were used in real-time PCR assay. No statistical differences were observed in the number of positive samples between culture method and real-time PCR (p>0.05) in all types of food samples. The number of positives of real-time PCR was higher in the first enrichment media (distilled water) than the second enrichment media (EE broth), though there was no significant difference (p>0.05). It appears that some components of the second enrichment broth, EE broth, inhibit the reaction of real-time PCR. These results show that real-time PCR using a single enrichment with distilled water could be useful as an effective screening method for detection of Cronobacter while saving much time and labor compared to conventional culture method.
Heat Shock-Induced Physical Changes of Megaplasmids in Rhodococcus sp. Strain DK17
Kim, Kyung-Sun ; Kim, Doc-Kyu ; Park, Hae-Youn ; Sung, Jung-Hee ; Kim, Eung-Bin ;
The Korean Journal of Microbiology, volume 47, issue 1, 2011, Pages 92~96
Rhodococcus sp. strain DK17 possesses three megaplasmids (380 kb pDK1, 330 kb pDK2, and 750 kb pDK3). The alkylbenzene-degrading genes (akbABCDEF) are present on pDK2 while the phthalate operons which are duplicated are present on both pDK2 (ophA'B'C'R') and pDK3 (ophABCR). DK17 with an optimal temperature of
showed no growth at
. When transferred to
, however, the
culture began to grow immediately, indicating that
is not lethal but stressful for DK17 growth. In addition, when exposed to
even for a short time, a part of DK17 cells lost the ability to degrade o-xylene (a model compound of alkylbenzenes). When two hundred colonies were randomly selected for colony PCR for pDK2-specific akbC, ophC', or pDK3-specific ophC, a total of 29 colonies were found to have lost at least one of the three genes. PFGE analysis clearly showed that all the mutants have different megaplasmid profiles from that of DK17 wild type, which are divided into five different cases: Type I (10 mutants, pDK2 loss and acquisition of a new ~700 kb plasmid), Type II (9 mutants, pDK2 loss), Type III (8 mutants, pDK3 loss and acquisition of a new ~400 kb plasmid), Type IV (1 mutant, pDK3 loss), and Type V (1 mutant, pDK2 and pDK3 loss and acquisition of the ~400 kb and ~700 kb plasmids). The above results showing that growth temperature changes can induce physical changes in bacterial genomes suggest that environmental changes in habitats including temperature fluctuations affect significantly the evolution of bacteria.
Isolation and Characteristics of Endolichenic Fungi Producing Antifungal Compound
Hwang, Hyun-Gook ; Kim, Yi-Na ; Baik, Keun-Sik ; Choi, Sang-Ki ;
The Korean Journal of Microbiology, volume 47, issue 1, 2011, Pages 97~101
To isolate a novel antifungal compound, we obtained 107 kinds of endolichenic fungi from Lichen Bioresources Center and examined their antifungal capability. Two fungi EL123 and EL156 showed high antifungal activity against Candida albicans in both MYA and EMM media. Nucleotide sequence analysis and NCBI Blast analysis in ITS region including 5.8S rRNA revealed that EL123 has 95% homology with Thielavia microspora and EL156, 99% with Cryptosporiopsis diversispora which belong to Ascomycetes. It observed that EL156 formed a branched mycelium whereas EL123 formed a straight one. EL156 also produced the antifungal substance faster than EL123 when they grew on MY liquid medium.