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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Microbiology and Biotechnology
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Journal DOI :
The Korean Society for Applied Microbiology and Biotechnology
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Volume & Issues
Volume 23, Issue 12 - Dec 2013
Volume 23, Issue 11 - Nov 2013
Volume 23, Issue 10 - Oct 2013
Volume 23, Issue 9 - Sep 2013
Volume 23, Issue 8 - Aug 2013
Volume 23, Issue 7 - Jul 2013
Volume 23, Issue 6 - Jun 2013
Volume 23, Issue 5 - May 2013
Volume 23, Issue 4 - Apr 2013
Volume 23, Issue 3 - Mar 2013
Volume 23, Issue 2 - Feb 2013
Volume 23, Issue 1 - Jan 2013
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Rapid, Sensitive, and Specific Detection of Clostridium tetani by Loop-Mediated Isothermal Amplification Assay
Jiang, Dongneng ; Pu, Xiaoyun ; Wu, Jiehong ; Li, Meng ; Liu, Ping ;
Journal of Microbiology and Biotechnology, volume 23, issue 1, 2013, Pages 1~6
DOI : 10.4014/jmb.1205.05063
Tetanus is a specific infectious disease, which is often associated with catastrophic events such as earthquakes, traumas, and war wounds. The obligate anaerobe Clostridium tetani is the pathogen that causes tetanus. Once the infection of tetanus progresses to an advanced stage within the wounds of limbs, the rates of amputation and mortality increase manifold. Therefore, it is necessary to devise a rapid and sensitive point-of-care detection method for C. tetani so as to ensure an early diagnosis and clinical treatment of tetanus. In this study, we developed a detection method for C. tetani using loop-mediated isothermal amplification (LAMP) assay, wherein the C. tetani tetanus toxin gene was used as the target gene. The method was highly specific and sensitive, with a detection limit of 10 colony forming units (CFU)/ml, and allowed quantitative analysis. While detecting C. tetani in clinical samples, it was found that the LAMP results completely agreed with those of the traditional API 20A anaerobic bacteria identification test. As compared with the traditional API test and PCR assay, LAMP detection of C. tetani is simple and rapid, and the results can be identified through naked-eye observation. Therefore, it is an ideal and rapid point-of-care testing method for tetanus.
Role of the Salt Bridge Between Arg176 and Glu126 in the Thermal Stability of the Bacillus amyloliquefaciens
Zonouzi, Roseata ; Khajeh, Khosro ; Monajjemi, Majid ; Ghaemi, Naser ;
Journal of Microbiology and Biotechnology, volume 23, issue 1, 2013, Pages 7~14
DOI : 10.4014/jmb.1205.05062
In the Bacillus amyloliquefaciens
-amylase (BAA), the loop (residues 176-185; region I) that is the part of the calcium-binding site (CaI, II) has two more amino acid residues than the
-amylase from Bacillus licheniformis (BLA). Arg176 in this region makes an ionic interaction with Glu126 from region II (residues 118-130), but this interaction is lost in BLA owing to substitution of R176Q and E126V. The goal of the present work was to quantitatively estimate the effect of ionic interaction on the overall stability of the enzyme. To clarify the functional and structural significance of the corresponding salt bridge, Glu126 was deleted (
E126) and converted to Val (E126V), Asp (E126D), and Lys (E126K) by site-directed mutagenesis. Kinetic constants, thermodynamic parameters, and structural changes were examined for the wild-type and mutated forms using UV-visible, atomic absoption, and fluorescence emission spectroscopy. Wild-type exhibited higher
but lower catalytic efficiency than the mutant enzymes. A decreased thermostability and an increased flexibility were also found in all of the mutant enzymes when compared with the wild-type. Additionally, the calcium content of the wild-type was more than
. Thus, it may be suggested that ionic interaction could decrease the mobility of the discussed region, prevent the diffusion of cations, and improve the thermostability of the whole enzyme. Based on these observations, the contribution of loop destabilization may be compensated by the formation of a salt bridge that has been used as an evolutionary mechanism or structural adaptation by the mesophilic enzyme.
"A La Recherche" of Functions for the Spore Protein SASP-E from Bacillus subtilis
Ruzal, Sandra M. ; Bustos, Patricia L. ; Sanchez-Rivas, Carmen ;
Journal of Microbiology and Biotechnology, volume 23, issue 1, 2013, Pages 15~21
DOI : 10.4014/jmb.1206.06028
We previously observed that Bacillus subtilis spores from sspE mutants presented a lower germination capacity in media containing high salt concentrations (0.9M NaCl). This deficiency was attributed to the absence of SASP-E (gamma-type small-acid-soluble protein), rich in osmocompatible amino acids released by degradation. Herein we observed that, in addition, this mutant spore presented a reduced capacity to use L-alanine as germinant (L-ala pathway), required longer times to germinate in calcium dipicolinate (
-DPA), but germinated well in asparagine, glucose, fructose, and potassium chloride (AGFK pathway). Moreover, mild sonic treatment of mutant spores partially recovered their germination capacity in L-ala. Spore qualities were also altered, since sporulating colonies from the sspE mutant showed a pale brownish color, a higher adherence to agar plates, and lower autofluorescence, properties related to their spore coat content. Furthermore, biochemical analysis showed a reduced partition in hexadecane and a higher content of
-DPA when compared with its isogenic wild-type control. Coat protein preparations showed a different electrophoretic pattern, in particular when detected with antibodies against CotG and CotE. The complementation with a wild-type sspE gene in a plasmid allowed for recovering the wild-type coat phenotype. This is the first report of a direct involvement of SASP-E in the spore coat assembly during the differentiation program of sporulation.
Homologous Expression and T3SS-Dependent Secretion of TAP-Tagged Xo2276 in Xanthomonas oryzae pv. oryzae Induced by Rice Leaf Extract and Its Direct In Vitro Recognition of Putative Target DNA Sequence
Kim, Seunghwan ; Nguyen, Thi-Dieu-Hanh ; Lee, Joohee ; Hong, Myoung-Ki ; Pham, Tan-Viet ; Ahn, Yeh-Jin ; Lee, Byoung-Moo ; Han, Ye Sun ; Kim, Dong-Eun ; Kim, Jeong-Gu ; Kang, Lin-Woo ;
Journal of Microbiology and Biotechnology, volume 23, issue 1, 2013, Pages 22~28
DOI : 10.4014/jmb.1207.07039
Xo2276 is a putative transcription activator-like effector (TALE) in Xanthomonas oryzae pv. oryzae (Xoo). Xo2276 was expressed with a TAP-tag at the C-terminus in Xoo cells to enable quantitative analysis of protein expression and secretion. Nearly all TAP-tagged Xo2276 existed in an insoluble form; addition of rice leaf extracts from a Xoosusceptible rice cultivar, Milyang23, significantly stimulated secretion of TAP-tagged Xo2276 into the medium. In a T3SS-defective Xoo mutant strain, secretion of TAPtagged Xo2276 was blocked. Xo2276 is a Xoo ortholog of Xanthomonas campestris pv. vesicatoria (Xcv) AvrBs3 and contains a conserved DNA-binding domain (DBD), which includes 19.5 tandem repeats of 34 amino acids. Xo2276- DBD was expressed in E. coli and purified. Direct in vitro recognition of Xo2276-DBD on a putative target DNA sequence was confirmed using an electrophoretic mobility shift assay. This is the first study measuring the homologous expression and secretion of Xo2276 in vitro using rice leaf extract and its direct in vitro binding to the specific target DNA sequence.
An Endophytic Nodulisporium sp. from Central America Producing Volatile Organic Compounds with Both Biological and Fuel Potential
Syed, Riyaz-Ul-Hassan ; Strobel, Gary ; Geary, Brad ; Sears, Joe ;
Journal of Microbiology and Biotechnology, volume 23, issue 1, 2013, Pages 29~35
DOI : 10.4014/jmb.1208.04062
A Nodulisporium sp. (Hypoxylon sp.) has been isolated as an endophyte of Thelypteris angustifolia (Broadleaf Leaf Maiden Fern) in a rainforest region of Central America. It has been identified both on the basis of its morphological characteristics and by scanning electron microscopy as well as ITS sequence analysis. The endophyte produces volatile organic compounds (VOCs) that have both fuel (mycodiesel) and use for biological control of plant disease. When grown on potato dextrose agar, the organism uniquely produces a series of ketones, including acetone; 2-pentanone; 3-hexanone, 4-methyl; 3-hexanone, 2,4-dimethyl; 2-hexanone, 4-methyl, and 5-hepten, 2-one and these account for about 25% of the total VOCs. The most abundant identified VOC was 1,8 cineole, which is commonly detected in this group of organisms. Other prominent VOCs produced by this endophyte include 1-butanol, 2-methyl, and phenylethanol alcohol. Moreover, of interest was the presence of cyclohexane, propyl, which is a common ingredient of diesel fuel. Furthermore, the VOCs of this isolate of Nodulisporium sp. were selectively active against a number of plant pathogens, and upon a 24 h exposure caused death to Phytophthora palmivora, Rhizoctonia solani, and Sclerotinia sclerotiorum and 100% inhibition to Phytophthora cinnamomi with only slight to no inhibition of the other pathogens that were tested. From this work, it is becoming increasingly apparent that each isolate of this endophytic Nodulisporium spp., including the Daldina sp. and Hypoxylon spp. teleomorphs, seems to produce its own unique set of VOCs.
Power Density Enhancement of Anion-Exchange Membrane-Installed Microbial Fuel Cell Under Bicarbonate-Buffered Cathode Condition
Piao, Jingmei ; An, Junyeong ; Ha, Phuc Thi ; Kim, Taeyoung ; Jang, Jae Kyung ; Moon3, Hyunsoo ; Chang, In Seop ;
Journal of Microbiology and Biotechnology, volume 23, issue 1, 2013, Pages 36~39
DOI : 10.4014/jmb.1211.11010
We introduce a high-performance microbial fuel cell (MFC) that was operated using a 0.1M bicarbonate buffer as the cathodic electrolyte. The MFC had a 136.42
maximum power density under continuous feeding of 5 mM acetate as fuel. Results of the electrode potential measurements showed that the cathode potential of the bicarbonate-buffered condition was higher than the phosphate-buffered condition, although the phosphate condition had less interfacial resistance between the membrane and electrolyte. Therefore, we posit here that the increased power of the bicarbonate-buffered MFC may be caused by the higher cathode potential rather than by the interfacial membrane-electrolyte resistance.
Analysis of Microflora Profile in Korean Traditional Nuruk
Song, Sang Hoon ; Lee, Chunghee ; Lee, Sulhee ; Park, Jung Min ; Lee, Hyong-Joo ; Bai, Dong-Hoon ; Yoon, Sung-Sik ; Choi, Jun Bong ; Park, Young-Seo ;
Journal of Microbiology and Biotechnology, volume 23, issue 1, 2013, Pages 40~46
DOI : 10.4014/jmb.1210.10001
A variety of nuruk were collected from various provinces in Korea, and their microflora profiles were analyzed at the species level. A total of 42 nuruk samples were collected and when the viable cell numbers in these nuruk were enumerated, the average cell numbers of bacteria, fungi, yeast, and lactic acid bacteria from all nuruk were 7.21, 7.91, 3.49, and 4.88 log CFU/10 g, respectively. There were no significant differences in viable cell numbers of bacteria or fungi according to regions collected. Bacillus amyloliquefaciens and B. subtilis were the predominant bacterial strains in most samples. A significant portion, 13 out of 42 nuruk, contained foodborne pathogens such as B. cereus or Cronobacter sakazakii. There were various species of lactic acid bacteria such as Enterococcus faecium and Pediococcus pentosaceus in nuruk. It was unexpectedly found that only 13 among the 42 nuruk samples contained Aspergillus oryzae, the representative saccharifying fungi in makgeolli, whereas a fungi Lichtheimia corymbifera was widely distributed in nuruk. It was also found that Pichia jadinii was the predominant yeast strain in most nuruk, but the representative alcohol fermentation strain, Saccharomyces cerevisiae, was isolated from only 18 out of the 42 nuruk. These results suggested that a variety of species of fungi and yeast were distributed in nuruk and involved in the fermentation of makgeolli. In this study, a total of 64 bacterial species, 39 fugal species, and 15 yeast species were identified from nuruk. Among these strains, 37 bacterial species, 20 fungal species, and 8 yeast species were distributed less than 0.1%.
Alteration of Media Composition and Light Conditions Change Morphology, Metabolic Profile, and Beauvericin Biosynthesis in Cordyceps bassiana Mycelium
Hyun, Sun-Hee ; Lee, Seok-Young ; Park, Shin Jung ; Kim, Da Yeon ; Chun, Young-Jin ; Sung, Gi-Ho ; Kim, Seong Hwan ; Choi, Hyung-Kyoon ;
Journal of Microbiology and Biotechnology, volume 23, issue 1, 2013, Pages 47~55
DOI : 10.4014/jmb.1208.08058
Metabolic alterations of Cordyceps bassiana mycelium were investigated under the following culture medium and light conditions: dextrose agar supplemented with 0.5% yeast extract (SDAY) medium with light (SL), SDAY medium without light (SD), nut medium without light (ND), and iron-supplemented SDAY medium without light (FD). The levels of asparagine, aspartic acid, glutamic acid, glutamine, histidine, lysine, ornithine, and proline were significantly higher under SD and SL conditions. The levels of most of the alcohols, saturated fatty acids, unsaturated fatty acids, fatty acid esters, sterols, and terpenes were higher under the ND condition than in the other conditions, but beauvericin was not detectable under the ND condition. The FD condition was favorable for the enhanced production of aminomalonic acid, malic acid, mannonic acid, and erythritol. Thus, the metabolic characteristics of C. bassiana can be manipulated by varying the cultivation conditions, rendering this fungus potentially favorable as a nutraceutical and medicinal resource.
Enzymatic Properties of a Thermostable
-Glucosidase from Acidothermophilic Crenarchaeon Sulfolobus tokodaii Strain 7
Park, Jung-Eun ; Park, So Hae ; Woo, Jung Yoon ; Hwang, Hye Sun ; Cha, Jaeho ; Lee, Heeseob ;
Journal of Microbiology and Biotechnology, volume 23, issue 1, 2013, Pages 56~63
DOI : 10.4014/jmb.1210.10019
We have characterized the putative
-glucosidase gene (st2525) selected by total genome analysis from the acidothermophilic crenarchaeon Sulfolobus tokodaii strain 7. The ORF was cloned and expressed as a fusion protein in Escherichia coli, and recombinant ST2525 was purified by Ni-NTA affinity chromatography. Maximum activity was observed at
and pH 4.0, and the enzyme exhibited stability with half-lives of 40.1 min and 7.75 min at extremely high temperatures of
, respectively. The enzyme retained at least 85% of its maximal activity in the pH range of 4.0-11.0. ST2525 exclusively hydrolyzed
-1,4-glycosidic linkages of oligosaccharides in an exo-type manner, with highest catalytic efficiency toward maltotriose. The enzyme also displayed transglycosylation activity, converting maltose to isomaltose, panose, maltotriose, isomaltotriose, etc. From these results, ST2525 could be potentially useful for starch hydrolysis as well as novel synthesis of oligosaccharides in industry.
Lactobacillus acidophilus Strain Suppresses the Transcription of Proinflammatory-Related Factors in Human HT-29 Cells
Chen, Kun ; Liang, Nailong ; Luo, Xuegang ; Zhang, Tong-Cun ;
Journal of Microbiology and Biotechnology, volume 23, issue 1, 2013, Pages 64~68
DOI : 10.4014/jmb.1208.04067
Previous studies have shown that lactic acid bacteria can inhibit inflammatory responses, but the mechanisms are very little known. In this study, transaction and expression of three proinflammatory factors, iNOS, PTGS-2, and IL8, which are closely related to the inflammatory response, were investigated by luciferase reporter assay and RTPCR in HT-29 cells treated by Lactobacillus acidophilus. The results showed that the live L. acidophilus sharply down-regulated the transcription of these three genes. Because there was a NF-
binding site located at -265 bp, -225 bp, and -95 bp upstream of the iNOS, PTGS-2, and IL8 promoters, respectively, we further addressed the effects of NF-
on transaction of the three promoters by cotransfection. As was expected, NF-
remarkably upregulated the activity of the reporter gene and, no effect of NF-
s on IL-8 promoter transaction was found after NF-
binding site mutation of the IL8 promoter in HT-29 cells. In conclusion, the live L. acidophilus decreased the transcriptional activity of NF-
and, in turn, inhibited the transaction of NF-
on the three proinflammatory factors mentioned above.
Production and Characterization of a Monoclonal Antibody Against Enrofloxacin
Chusri, Manaspong ; Wongphanit, Pitikarn ; Palaga, Tanapat ; Puthong, Songchan ; Sooksai, Sarintip ; Komolpis, Kittinan ;
Journal of Microbiology and Biotechnology, volume 23, issue 1, 2013, Pages 69~75
DOI : 10.4014/jmb.1201.01017
Enrofloxacin is a fluoroquinolone antibiotic approved for the treatment of infections in animals. Because of the side effects to consumers of animal products, the maximum residue limits (MRLs) of enrofloxacin in animal tissues for consumption are regulated. In this study, a monoclonal antibody (mAb) against enrofloxacin was prepared and characterized for the development of a direct competitive enzyme-linked immunosorbent assay (ELISA). The obtained mAb, Enro44, was highly specific for enrofloxacin and had a 50% inhibition concentration (
) of 1.99 ng/ml in a competitive ELISA, and the limit of detection (LOD) was 0.50 ng/ml. The cross-reactivity of the mAb with other quinolones and fluoroquinolones was lower than 0.01%. The subclass of the mAb Enro44 was identified as IgG1. The antigen (Ag)-captured direct competitive ELISA using the mAb Enro44 was tested on different spiked samples, including chicken muscle, cattle milk, and cattle urine, and the assay demonstrated recoveries of 82-112%, 80-125%, and 78-124%, respectively. Furthermore, the quantitation of enrofloxacin obtained from the ELISA and from high-performance liquid chromatography (HPLC) was in good agreement, with the linear regression coefficient between 0.933 and 1.056. The cDNAs encoding a heavy-chain Fd fragment (VH and CH1) and a light chain of the mAb Enro44 were cloned and sequenced. Taken together, the results obtained reveal a potential use of this mAb in an ELISA for the detection of enrofloxacin in food samples. The information of amino acid sequence of this mAb will be useful for further modification and production of the mAb in a bioreactor.
Comparison of Bacterial Community Changes in Fermenting Kimchi at Two Different Temperatures Using a Denaturing Gradient Gel Electrophoresis Analysis
Yeun, Hong ; Yang, Hee-Seok ; Chang, Hae-Choon ; Kim, Hae-Yeong ;
Journal of Microbiology and Biotechnology, volume 23, issue 1, 2013, Pages 76~84
DOI : 10.4014/jmb.1210.10002
A polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) technique followed by sequencing of the 16S rDNA fragments eluted from the bands of interest on denaturing gradient gels was used to monitor changes in the bacterial microflora of two commercial kimchi, salted cabbage, and ingredient mix samples during 30 days of fermentation at
. Leuconostoc (Lc.) was the dominant lactic acid bacteria (LAB) over Lactobacillus (Lb.) species at
. Weissella confusa was detected in the ingredient mix and also in kimchi samples throughout fermentation in both samples at
. Lc. gelidum was detected as the dominant LAB at
in both samples. The temperature affected the LAB profile of kimchi by varing the pH, which was primarily caused by the temperature-dependent competition among different LAB species in kimchi. At
, the sample variations in pH and titratable acidity were more conspicuous owing to the delayed growth of LAB. Temperature affected only initial decreases in pH and initial increases in viable cell counts, but affected both the initial increases and final values of titratable acidity. The initial microflora in the kimchi sample was probably determined by the microflora of the ingredient mix, not by that of the salted cabbage. The microbial distributions in the samples used in this study resembled across the different kimchi samples and the different fermentation temperatures as the numbers of LAB increased and titratable acidity decreased.
A Foodborne Outbreak of Staphylococcus aureus Associated with Fried Chicken in Republic of Korea
Hyeon, Ji-Yeon ; Chung, Gyung-Tae ; Bing, Sun-Hye ; Kwon, Kyung-Sook ; Lee, Hyeon-Hee ; Kim, Soo-Jin ; Jeon, Se-Eun ; Kang, Yeon-Ho ; Kim, Junyoung ;
Journal of Microbiology and Biotechnology, volume 23, issue 1, 2013, Pages 85~87
DOI : 10.4014/jmb.1210.10022
An outbreak of Staphylococcus aureus infections occurred in a university with an enrollment of 80 students in the city of Daejon, Republic of Korea. All nine S. aureus isolates from patients (n = 7), staff members (n = 1), and the fried chicken served as the lunch (n = 1) harbored the enterotoxin A gene and showed an identical antibioticresistant profile, PFGE banding pattern (STAS16.001), and sequence type, ST 6. These results suggested that the outbreak was associated with eating the fried chicken that had been handled by an infected staff member. This case report demonstrated a practical approach to identifying the source and transmission of an infection.
Cyt1Aa from Bacillus thuringiensis subsp. israelensis Enhances Mosquitocidal Activity of B. thuringiensis subsp. kurstaki HD-1 Against Aedes aegypti but not Culex quinquefasciatus
Park, Hyun-Woo ; Pino, Brent C. ; Kozervanich-Chong, Switzerlyna ; Hafkenscheid, Erika A. ; Oliverio, Ryan M. ; Federici, Brian A. ; Bideshi, Dennis K. ;
Journal of Microbiology and Biotechnology, volume 23, issue 1, 2013, Pages 88~91
DOI : 10.4014/jmb.1207.07061
The Cyt1Aa protein of Bacillus thuringiensis subsp. israelensis is known to synergize mosquitocidal proteins of B. thuringiensis and Bacillus sphaericus strains. Cyt1Aa is highly lipophilic, and after binding in vivo to the midgut microvillar membrane serves as a "receptor" for mosquitocidal Cry proteins, which subsequently form cation channels that kill mosquito larvae. Here we report that Cyt1Aa can serve a similar function for lepidopteran-specific Cry proteins of B. thuringiensis in certain mosquito larvae. Engineering Cyt1Aa into the HD-1 isolate of B. thuringiensis subsp. kurstaki enhanced toxicity against
instars of Aedes aegypti, but not against
instars of Culex quinquefasciatus.
Increased Microalgae Growth and Nutrient Removal Using Balanced N:P Ratio in Wastewater
Lee, Seung-Hoon ; Ahn, Chi-Yong ; Jo, Beom-Ho ; Lee, Sang-Ah ; Park, Ji-Yeon ; An, Kwang-Guk ; Oh, Hee-Mock ;
Journal of Microbiology and Biotechnology, volume 23, issue 1, 2013, Pages 92~98
DOI : 10.4014/jmb.1210.10033
Microalgal cultivation using wastewater is now regarded as essential for biodiesel production, as two goals can be achieved simultaneously; that is, nutrient removal efficiency and biomass production. Therefore, this study examined the effects of carbon sources, the N:P ratio, and the hydraulic retention time (HRT) to identify the optimal conditions for nutrient removal efficiency and biomass production. The effluent from a 2nd lagoon was used to cultivate microalgae. Whereas the algal species diversity and lipid content increased with a longer HRT, the algal biomass productivity decreased. Different carbon sources also affected the algal species composition. Diatoms were dominant with an increased pH when bicarbonate was supplied. However, 2%
gas led to a lower pH and the dominance of filamentous green algae with a much lower biomass productivity. Among the experiments, the highest chlorophyll-a concentration and lipid productivity were obtained with the addition of phosphate up to 0.5 mg/l P, since phosphorus was in short supply compared with nitrogen. The N and P removal efficiencies were also higher with a balanced N:P ratio, based on the addition of phosphate. Thus, optimizing the N:P ratio for the dominant algae could be critical in attaining higher algal growth, lipid productivity, and nutrient removal efficiency.
Effect of Aeration on Nitrous Oxide (
) Emission from Nitrogen-Removing Sequencing Batch Reactors
Kim, Dong-Jin ; Kim, Yuri ;
Journal of Microbiology and Biotechnology, volume 23, issue 1, 2013, Pages 99~105
DOI : 10.4014/jmb.1206.06001
In this study, nitrous oxide (
) emission was compared between the operations of two different sequencing batch reactors, conventional sequencing batch reactor (CNVSBR) and simultaneous nitrification and denitrification sequencing batch reactor (SND-SBR), using synthetic wastewater. The CNV-SBR consisted of anoxic (denitrification) and aerobic phases, whereas the SND-SBR consisted of a microaerobic (low dissolved oxygen concentration) phase, which was achieved by intermittent aeration for simultaneous nitrification and denitrification. The CNV-SBR emitted 3.9 mg of
-N in the denitrification phase and 1.6 mg of
-N in the nitrification phase, resulting in a total emission of 5.5mg from 432mg of
-N input. In contrast, the SND-SBR emitted 26.2mg of
-N under the microaerobic condition, which was about 5 times higher than the emission obtained with the CNV-SBR at the same
-N input. From the
yield based on
-N input, the microaerobic condition produced the highest yield (6.1%), followed by the anoxic (0.9%) and aerobic (0.4%) conditions. It is thought that an appropriate dissolved oxygen level is critical for reducing
emission during nitrification and denitrification at wastewater treatment plants.
Microbial Consortia in Oman Oil Fields: A Possible Use in Enhanced Oil Recovery
Al-Bahry, Saif N. ; Elsahfie, Abdulkader E. ; Al-Wahaibi, Yahya M. ; Al-Bimani, Ali S. ; Joshi, Sanket J. ; Al-Maaini, Ratiba A. ; Al-Alawai, Wafa J. ; Sugai, Yuichi ; Al-Mandhari, Mussalam ;
Journal of Microbiology and Biotechnology, volume 23, issue 1, 2013, Pages 106~117
DOI : 10.4014/jmb.1204.04021
Microbial enhanced oil recovery (MEOR) is one of the most economical and efficient methods for extending the life of production wells in a declining reservoir. Microbial consortia from Wafra oil wells and Suwaihat production water, Al-Wusta region, Oman were screened. Microbial consortia in brine samples were identified using denaturing gradient gel electrophoresis and 16S rRNA gene sequences. The detected microbial consortia of Wafra oil wells were completely different from microbial consortia of Suwaihat formation water. A total of 33 genera and 58 species were identified in Wafra oil wells and Suwaihat production water. All of the identified microbial genera were first reported in Oman, with Caminicella sporogenes for the first time reported from oil fields. Most of the identified microorganisms were found to be anaerobic, thermophilic, and halophilic, and produced biogases, biosolvants, and biosurfactants as by-products, which may be good candidates for MEOR.
Lactobacillus brevis KB290 Enhances IL-8 Secretion by Vibrio parahaemolyticus-Infected Caco-2 Cells
Yakabe, Takafumi ; Shimohata, Takaaki ; Takahashi, Akira ;
Journal of Microbiology and Biotechnology, volume 23, issue 1, 2013, Pages 118~124
DOI : 10.4014/jmb.1207.07020
Vibrio parahaemolyticus in uncooked seafood causes acute gastroenteritis. The microorganism has two sets of type III secretion systems and two hemolysins. When it injects its effector proteins into a host cell via type III secretion system 1, one of the type III secretion systems induces secretion of interleukin (IL)-8, a proinflammatory chemokine, through the phosphorylation of ERK 1/2 and p38 MAPK. Although probiotics have beneficial effects on hosts and can help control some infectious diseases, there is little research on the efficacy of probiotics in V. parahaemolyticus infection. Here we pretreated V. parahaemolyticus-infected human intestinal epithelial cells with heat-killed Lactobacillus brevis KB290, a probiotic isolated from fermented vegetables (traditional Japanese pickles) and utilized as an ingredient of beverages and supplementary foods, and demonstrated its efficacy in enhancing IL-8 secretion from V. parahaemolyticus-infected cells. Among the three heat-killed lactic acid bacterial strains we tested, L. brevis KB290 induced the highest level of IL-8 secretions in the infected cells. Relative to control cells (Caco-2 cells pretreated with PBS), V. parahaemolyticus-infected Caco-2 cells pretreated with heat-killed L. brevis KB290 secreted IL-8 earlier, although concentrations were similar 450min after infection. Heat-killed L. brevis KB290 pretreatment also induced earlier ERK 1/2 phosphorylation, greater p38 MAPK phosphorylation, and enhanced IL-8 mRNA expression. Heat-killed L. brevis KB290 accelerated IL-8 secretion, a host cell immune response, in V. parahaemolyticus-infected cells. We consider this to be beneficial because IL-8 plays an important defensive role against infection, and would contribute to the repair of injured epithelial cells.
Antiviral Activity of the Plant Extracts from Thuja orientalis, Aster spathulifolius, and Pinus thunbergii Against Influenza Virus A/PR/8/34
Won, Ji-Na ; Lee, Seo-Yong ; Song, Dae-Sub ; Poo, Haryoung ;
Journal of Microbiology and Biotechnology, volume 23, issue 1, 2013, Pages 125~130
DOI : 10.4014/jmb.1210.10074
Influenza viruses cause significant morbidity and mortality in humans through epidemics or pandemics. Currently, two classes of anti-influenza virus drugs, M2 ion-channel inhibitors (amantadin and rimantadine) and neuraminidase inhibitors (oseltamivir and zanamivir), have been used for the treatment of the influenza virus infection. Since the resistance to these drugs has been reported, the development of a new antiviral agent is necessary. In this study, we examined the antiviral efficacy of the plant extracts against the influenza A/PR/8/34 infection. In vitro, the antiviral activities of the plant extracts were investigated using the cell-based screening. Three plant extracts, Thuja orientalis, Aster spathulifolius, and Pinus thunbergii, were shown to induce a high cell viability rate after the infection with the influenza A/PR/8/34 virus. The antiviral activity of the plant extracts also increased as a function of the concentration of the extracts and these extracts significantly reduced the visible cytopathic effect caused by virus infections. Furthermore, the treatment with T. orientalis was shown to have a stronger inhibitory effect than that with A. spathulifolius or P. thunbergii. These results may suggest that T. orientalis has anti-influenza A/PR/8/34 activity.
Synthesis of NBD-Labeled DOTAP Analog to Track Intracellular Delivery of Liposome
Doh, Kyung-Oh ; Kim, Bieong-Kil ; Lee, Tae-Jin ; Park, Jong-Won ; Seu, Young-Bae ;
Journal of Microbiology and Biotechnology, volume 23, issue 1, 2013, Pages 131~135
DOI : 10.4014/jmb.1208.08083
A DOTAP analog labeled by NBD on the head group (DTNBD) was designed and synthesized to label DOTAP liposome. The structure was confirmed by
NMR and FAB-MS, and the fluorescence of the newly synthesized DT-NBD was observed by fluorescent microscopy. The transfection efficiency of DOTAP liposome containing DT-NBD was comparable to commonly used NBD PE in COS7 and MCF7 cells. Furthermore, the level of cellular uptake and fluorescent intensity of fluorescent liposome containing DT-NBD was higher than NBD PE. Therefore, the novel NBD-labeled DOTAP analog seems to be effectively used for investigation of the cellular interaction and transfection mechanism of DOTAP liposome.