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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 22, Issue 12 - Dec 2012
Volume 22, Issue 11 - Nov 2012
Volume 22, Issue 10 - Oct 2012
Volume 22, Issue 9 - Sep 2012
Volume 22, Issue 8 - Aug 2012
Volume 22, Issue 7 - Jul 2012
Volume 22, Issue 6 - Jun 2012
Volume 22, Issue 5 - May 2012
Volume 22, Issue 4 - Apr 2012
Volume 22, Issue 3 - Mar 2012
Volume 22, Issue 2 - Feb 2012
Volume 22, Issue 1 - Jan 2012
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Comparison of Ammonia-Oxidizing Bacterial Community Structure in Membrane-Assisted Bioreactors Using PCR-DGGE and FISH
Ziembinska, A. ; Ciesielski, S. ; Gnida, A. ; Zabczynski, S. ; Surmacz-Gorska, J. ; Miksch, K. ;
Journal of Microbiology and Biotechnology, volume 22, issue 8, 2012, Pages 1035~1043
DOI : 10.4014/jmb.1201.01014
The ammonia-oxidizing bacterial (AOB) communities in three membrane bioreactors (MBRs) were monitored for 2 months after an acclimation period in order to investigate the influence of sludge age and medium type on AOB changeability and its connection with nitrification effectiveness. One MBR with a sludge age of 4 days was fed with a synthetic medium, whereas the other two with sludge ages of 8 and 32 days were fed with landfill leachate. The research revealed that landfill leachate can be effectively treated in an MBR with a higher sludge age for longer periods of time and that this improvement in performance was correlated with an increase in AOB biodiversity. Interestingly, the medium type has a stronger influence on AOB biocenosis formation than the sludge age.
Cloning and Identification of a New Group Esterase (Est5S) from Noncultured Rumen Bacterium
Kim, Min Keun ; Kang, Tae Ho ; Kim, Jungho ; Kim, Hoon ; Yun, Han Dae ;
Journal of Microbiology and Biotechnology, volume 22, issue 8, 2012, Pages 1044~1053
DOI : 10.4014/jmb.1201.12070
The gene encoding an esterase enzyme was cloned from a metagenomic library of cow rumen bacteria. The esterase gene (est5S) was 1,026 bp in length, encoding a protein of 366 amino acid residues with a calculated molecular mass of 40,168 Da. The molecular mass of the enzyme was estimated to be 40,000 Da. The Est5S protein contains the Gly-X-Ser-X-Gly motif found in most bacterial and eukaryotic serine hydrolases. However, the Asp or Glu necessary for the catalytic triad [Ser-Asp-(Glu)-His] was not present, indicating Est5S represents a novel member of the GHSQG family of esterolytic enzymes. BlastP in the NCBI database analysis of Est5S revealed homology to hypothetical proteins and it had no homology to previous known lipases and esterases. Est5S was optimally active at pH 7.0 and
. Among the p-nitrophenyl acylesters tested, high enzymatic activities were observed on the short-chain p-nitrophenyl acylesters, such as p-nitrophenyl acetate, etc. The conserved serine residue (
) was shown to be important for Est5S activity. The primers that amplified the est5S gene did not show any relative band with 49 species of culturable rumen bacteria. This implies that a new group esterase gene, est5S, may have come from a noncultured cow rumen bacterium.
Algorithm for Predicting Functionally Equivalent Proteins from BLAST and HMMER Searches
Yu, Dong Su ; Lee, Dae-Hee ; Kim, Seong Keun ; Lee, Choong Hoon ; Song, Ju Yeon ; Kong, Eun Bae ; Kim, Jihyun F. ;
Journal of Microbiology and Biotechnology, volume 22, issue 8, 2012, Pages 1054~1058
DOI : 10.4014/jmb.1203.03050
In order to predict biologically significant attributes such as function from protein sequences, searching against large databases for homologous proteins is a common practice. In particular, BLAST and HMMER are widely used in a variety of biological fields. However, sequence-homologous proteins determined by BLAST and proteins having the same domains predicted by HMMER are not always functionally equivalent, even though their sequences are aligning with high similarity. Thus, accurate assignment of functionally equivalent proteins from aligned sequences remains a challenge in bioinformatics. We have developed the FEP-BH algorithm to predict functionally equivalent proteins from protein-protein pairs identified by BLAST and from protein-domain pairs predicted by HMMER. When examined against domain classes of the Pfam-A seed database, FEP-BH showed 71.53% accuracy, whereas BLAST and HMMER were 57.72% and 36.62%, respectively. We expect that the FEP-BH algorithm will be effective in predicting functionally equivalent proteins from BLAST and HMMER outputs and will also suit biologists who want to search out functionally equivalent proteins from among sequence-homologous proteins.
Biotransformation of Flavone by CYP105P2 from Streptomyces peucetius
Niraula, Narayan Prasad ; Bhattarai, Saurabh ; Lee, Na-Rae ; Sohng, Jae Kyung ; Oh, Tae-Jin ;
Journal of Microbiology and Biotechnology, volume 22, issue 8, 2012, Pages 1059~1065
DOI : 10.4014/jmb.1201.01037
Biocatalytic transfer of oxygen in isolated cytochrome P450 or whole microbial cells is an elegant and efficient way to achieve selective hydroxylation. Cytochrome P450 CYP105P2 was isolated from Streptomyces peucetius that showed a high degree of amino acid identity with hydroxylases. Previously performed homology modeling, and subsequent docking of the model with flavone, displayed a reasonable docked structure. Therefore, in this study, in a pursuit to hydroxylate the flavone ring, CYP105P2 was co-expressed in a two-vector system with putidaredoxin reductase (camA) and putidaredoxin (camB) from Pseudomonas putida for efficient electron transport. HPLC analysis of the isolated product, together with LC-MS analysis, showed a monohydroxylated flavone, which was further established by subsequent ESI/MS-MS. A successful 10.35% yield was achieved with the whole-cell bioconversion reaction in Escherichia coli. We verified that CYP105P2 is a potential bacterial hydroxylase.
Construction, and In Vitro and In Vivo Analyses of Tetravalent Immunoadhesins
Cho, Hoonsik ; Chung, Yong-Hoon ;
Journal of Microbiology and Biotechnology, volume 22, issue 8, 2012, Pages 1066~1076
DOI : 10.4014/jmb.1201.01026
Previous observations demonstrated that various immunosuppressive agents and their combination therapies can increase allograft survival rates. However, these treatments may have serious side effects and cannot substantially improve or prolong graft survival in acute graft-versus-host disease (GVHD). To improve the therapeutic potency of divalent immunoadhesins, we have constructed and produced several tetravalent forms of immunoadhesins comprising each of cytotoxic T-lymphocyte-associated antigen-4 (CTLA4), CD2, and lymphocyte activation gene-3 (LAG3). Flow cytometric and T cell proliferation analyses displayed that tetravalent immunoadhesins have a higher binding affinity and more potent efficacy than divalent immunoadhesins. Although all tetravalent immunoadhesins possess better efficacies, tetravalent forms of CTLA4-Ig and LAG3-Ig revealed higher inhibitory effects on T cell proliferation than tetravalent forms of TNFR2-Ig and CD2-Ig. In vitro mixed lymphocytes reaction (MLR) showed that combined treatment with tetravalent CTLA4-Ig and tetravalent LAG3-Ig was highly effective for inhibiting T cell proliferation in both human and murine allogeneic stimulation. In addition, both single tetravalent-form and combination treatments can prevent the lethality of murine acute GVHD. The results of this study demonstrated that co-blockade of the major histocompatibility complex class (MHC)II:T cell receptor (TCR) and CD28:B7 pathways by using tetravalent human LAG3-Ig and CTLA4-Ig synergistically prevented murine acute GVHD.
Investigations on Possible Roles of C-Terminal Propeptide of a Ca-Independent
-Amylase from Bacillus
Salimi, Ali ; Yousefi, Fatemeh ; Ghollasi, Marzieh ; Daneshjou, Sara ; Tavoli, Hesam ; Ghobadi, Sirous ; Khajeh, Khosro ;
Journal of Microbiology and Biotechnology, volume 22, issue 8, 2012, Pages 1077~1083
DOI : 10.4014/jmb.1112.11085
Previously, an extracellular
-amylase (BKA) had been purified from the culture of Bacillus sp. KR8104. Subsequently, the crystal structure of the active enzyme revealed a 422 amino acids polypeptide. In this study, the bka was cloned into E. coli, which encoded a polypeptide of 659 amino acids including two additional fragments: one 44 residues N-terminal fragment and another 193 residues C-terminal fragment. In order to investigate the role of the C-terminal fragment, two constructs with and without this region [
(N44C193)] were designed and expressed in E. coli BL21. The optimum pH, thermal stability, and the end-products of starch hydrolysis were found to be similar in both constructs. The
(N44) were lower than
(N44C193), using either starch or ethylidene-blocked 4-nitrophenylmaltoheptaoside as a substrate.
Biosynthesis of Xylobiose: A Strategic Way to Enrich the Value of Oil Palm Empty Fruit Bunch Fiber
Lakshmi, G. Suvarna ; Rajeswari, B. Uma ; Prakasham, R.S. ;
Journal of Microbiology and Biotechnology, volume 22, issue 8, 2012, Pages 1084~1091
DOI : 10.4014/jmb.1202.02005
Xylooligosaccharides are functional foods mainly produced during the hydrolysis of xylan by physical, chemical, or enzymatic methods. In this study, production of xylobiose was investigated using oil palm empty fruit bunch fiber (OPEFB) as a source material, by chemical and enzymatic methods. Xylanase-specific xylan hydrolysis followed by xylobiose production was observed. Among different xylanases, xylanase from FXY-1 released maximum xylobiose from pretreated OPEFB fiber, and this fungal strain was identified as Aspergillus terreus and subsequently deposited under the accession Number MTCC- 8661. The imperative role of lignin on xylooligosaccharides enzymatic synthesis was exemplified with the notice of xylobiose production only with delignified material. A maximum 262 mg of xylobiose was produced from 1.0 g of pretreated OPEFB fiber using FXY-1 xylanase (6,200 U/ml) at pH 6.0 and
. At optimized environment, the yield of xylobiose was improved to 78.67 g/100 g (based on xylan in the pretreated OPEFB fiber).
Properties of Bac W42, a Bacteriocin Produced by Bacillus subtilis W42 Isolated from Cheonggukjang
Kindoli, Salum ; Lee, Hwang A ; Kim, Jeong Hwan ;
Journal of Microbiology and Biotechnology, volume 22, issue 8, 2012, Pages 1092~1100
DOI : 10.4014/jmb.1110.10002
Ten Bacillus strains with antimicrobial activities were isolated from Cheonggukjang produced at different parts in Korea. They all inhibited Listeria monocytogenes ATCC 19111 and nine inhibited Bacillus cereus ATCC 14579. Four isolates (W42, H27, SKE 12, and K21) showing strong inhibiting activities were identified as B. subtilis. B. subtilis W42 was the most inhibiting strain. The antimicrobial activity of culture supernatant from B. subtilis W42 was destroyed completely by proteinase K treatment, indicating that a bacteriocin was the responsible agent. The bacteriocin, Bac W42, was most stable at pH 7 and stable between pH 3-6 and 8-9. Bac W42 was stable up to
. BHI (brain heart infusion) and TSB (tryptic soy broth) were the best media for the activity (320 AU/ml) followed by LB (160 AU/ml). Bac W42 was partially purified by column chromatographies. The specific activity was increased from 1,151.2 AU/ml to 9,043.5 AU/ml and the final yield was 26.3%. Bac W42 was 5.4 kDa in size as determined by SDS-PAGE. Bac W42 showed bactericidal activity against L. monocytogenes ATCC 19111.
Microbial Dynamics of Commercial Makgeolli Depending on the Storage Temperature
Kim, Hye-Ryun ; Lee, Ae Ran ; Kim, Jae-Ho ; Ahn, Byung-Hak ;
Journal of Microbiology and Biotechnology, volume 22, issue 8, 2012, Pages 1101~1106
DOI : 10.4014/jmb.1112.12063
Market fresh makgeolli was stored at different temperatures of
to assess the change of the microbial diversity according to the storage temperature and period. Yeast counts increased until day 3 of storage and decreased thereafter. General and lactic acid bacterial counts continuously increased during storage. The data indicated that the control of growth of microorganisms, particularly general bacteria and lactic acid bacteria (LAB), is essential. Total acid levels started to decrease in the makgeolli stored at
, and increased from day 6 of storage in the makgeolli stored at
. The increase of total acid in the non-refrigerated condition greatly affected the quality of makgeolli. In both the fresh makgeolli samples stored at
, yeast (Saccharomyces cerevisiae) and molds (Aspergillus tubingensis, Candida glaebosa, and Aspergillus niger) were noted. Denaturing gradient gel electrophoresis (DGGE) band patterns were almost constant regardless of the storage period. As for bacteria, Lactobacillus crustorum, L. brevis, and Microlaena stipoides were found in the makgeolli stored at
, and L. crustorum, Lactobacillus sp., L. plantarum, L. brevis, L. rhamnosus, and L. similis were found in the makgeolli stored at
. In particular, in the makgeolli stored at
, L. crustorum and L. plantarum presented dark bands and were identified as the primary microorganisms that affected spoilage of fresh makgeolli.
Detection and Identification of Vibrio Species Using Whole-Cell Protein Pattern Analysis
Lee, Chae-Yoon ; Hong, Yeun ; Ryu, Jio ; Kim, Young-Rok ; Oh, Sang-Suk ; Lee, Soon-Ho ; Hwang, In-Gyun ; Kim, Hae-Yeong ;
Journal of Microbiology and Biotechnology, volume 22, issue 8, 2012, Pages 1107~1112
DOI : 10.4014/jmb.1201.01001
Outbreaks of foodborne diseases associated with Vibrio species such as V. parahaemolyticus, V. vulnificus, and V. cholerae frequently occur in countries having a dietary habit of raw seafood consumption. For rapid identification of different Vibrio species involved in foodborne diseases, whole-cell protein pattern analysis for 13 type strains of 12 Vibrio species was performed using SDS-PAGE analysis. Pathogenic Vibrio species such as V. parahaemolyticus, V. vulnificus, V. cholerae, V. alginolyticus, V. fluvialis, and V. mimicus were included in the 12 Vibrio species used in this study. Each of the 12 Vibrio species showed clearly specific band patterns of its own. Two different strains of V. parahaemolyticus showed two different SDS-PAGE whole-cell protein patterns, giving the possibility of categorizing isolated strains in the same V. parahaemolyticus species into two subgroups. The 36 Vibrio isolates collected from sushi restaurants in Busan were all identified as V. parahaemolyticus by comparing their protein patterns with those of Vibrio type strains. The identified isolates were categorized into two different subgroups of V. parahaemolyticus. The whole-cell protein pattern analysis by SDS-PAGE can be used as a specific, rapid, and simple identification method for Vibrio spp. involved in foodborne diseases at the subspecies level.
A Novel Marker for the Species-Specific Detection and Quantitation of Shigella sonnei by Targeting a Methylase Gene
Cho, Min Seok ; Ahn, Tae-Young ; Joh, Kiseong ; Kwon, Oh-Sang ; Jheong, Won-Hwa ; Park, Dong Suk ;
Journal of Microbiology and Biotechnology, volume 22, issue 8, 2012, Pages 1113~1117
DOI : 10.4014/jmb.1111.11006
Shigella sonnei is a causal agent of fever, nausea, stomach cramps, vomiting, and diarrheal disease. The present study describes a quantitative polymerase chain reaction (qPCR) assay for the specific detection of S. sonnei using a primer pair based on the methylase gene for the amplification of a 325 bp DNA fragment. The qPCR primer set for the accurate diagnosis of Shigella sonnei was developed from publically available genome sequences. This quantitative PCR-based method will potentially simplify and facilitate the diagnosis of this pathogen and guide disease management.
Characterization of the Four GH12 Endoxylanases from the Plant Pathogen Fusarium graminearum
Habrylo, Olivier ; Song, Xinghan ; Forster, Anne ; Jeltsch, Jean-Marc ; Phalip, Vincent ;
Journal of Microbiology and Biotechnology, volume 22, issue 8, 2012, Pages 1118~1126
DOI : 10.4014/jmb.1112.11019
Four putative GH12 genes were found in the Fusarium graminearum genome. The corresponding proteins were expressed in Escherichia coli, purified, and evaluated. FGSG_05851 and FGSG_11037 displayed high activities towards xyloglucan (
of 4 and
, respectively), whereas FGSG_07892 and FGSG_16349 were much less active with this substrate (0.081 and
, respectively). However, all four of these enzymes had a similar binding affinity for xyloglucan. Xyloglucan was the substrate preferred by FGSG_05851, in contrast to the three other enzymes, which preferred
-glucan or lichenan. Therefore, FGSG_05851 is a xyloglucan-specific glucanase (E.C. 22.214.171.124) rather than an endoglucanase (E.C. 126.96.36.199) with broad substrate specificity. FGSG_11037 displayed a peculiar behavior in that the xyloglucan binding was highly cooperative, with a Hill coefficient of 2.5. Finally, FGSG_05851 essentially degraded xyloglucan into hepta-, octa-, and nonasaccharides, whereas the three other enzymes yielded hepta- and octa-saccharides as well as larger molecules.
Effect of Different Biosynthetic Precursors on the Production of Nargenicin
from Metabolically Engineered Nocardia sp. CS682
Koju, Dinesh ; Maharjan, Sushila ; Dhakal, Dipesh ; Yoo, Jin Cheol ; Sohng, Jae Kyung ;
Journal of Microbiology and Biotechnology, volume 22, issue 8, 2012, Pages 1127~1132
DOI : 10.4014/jmb.1202.02027
is a 28-membered polyketide macrolide, with antibacterial activity against methicillin-resistant Staphylococcus aureus, produced by Nocardia sp. CS682. In this study, the production of nargenicin
was improved by enhancing the supply of different biosynthetic precursors. In Nocardia sp. CS682 (KCTC11297BP), this improvement was ~4.62-fold with the supplementation of 30 mM methyl oleate, 4.25-fold with supplementation of 15mM sodium propionate, and 2.81-fold with supplementation of 15 mM sodium acetate. In Nocardia sp. metK18 and Nocardia sp. CS682 expressing S-adenosylmethionine synthetase (MetK), the production of nargenicin
was improved by ~5.57-fold by supplementation with 30 mM methyl oleate, 5.01-fold by supplementation with 15 mM sodium propionate, and 3.64-fold by supplementation with 15 mM sodium acetate. Furthermore, supplementing the culture broth of Nocardia sp. ACC18 and Nocardia sp. CS682 expressing the acetyl-CoA carboxylase complex (AccA2 and AccBE) with 30 mM methyl oleate, 15 mM sodium propionate, or 15 mM sodium acetate resulted in ~6.99-, 6.46-, and 5.58-fold increases, respectively, in nargenicin
production. Our overall results showed that among the supplements, methyl oleate was the most effective precursor supporting the highest titers of nargenicin
in Nocardia sp. CS682, Nocardia sp. metK18, and Nocardia sp. ACC18.
Improving Cellulase Production in Trichoderma koningii Through RNA Interference on ace1 Gene Expression
Wang, Shao-Wen ; Xing, Miao ; Liu, Gang ; Yu, Shao-Wen ; Wang, Juan ; Tian, Sheng-Li ;
Journal of Microbiology and Biotechnology, volume 22, issue 8, 2012, Pages 1133~1140
DOI : 10.4014/jmb.1112.12037
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.
Detection of Polyhydroxyalkanoate-Accumulating Bacteria from Domestic Wastewater Treatment Plant Using Highly Sensitive PCR Primers
Huang, Yu-Tzu ; Chen, Pi-Ling ; Semblante, Galilee Uy ; You, Sheng-Jie ;
Journal of Microbiology and Biotechnology, volume 22, issue 8, 2012, Pages 1141~1147
DOI : 10.4014/jmb.1111.11040
Polyhydroxyalkanoate (PHA) is a class of biodegradable plastics that have great potential applications in the near future. In this study, the micro-biodiversity and productivity of PHA-accumulating bacteria in activated sludge from a domestic wastewater treatment plant were investigated. A previously reported primer set and a self-designed primer set (phaCF1BO/phaCR2BO) were both used to amplify the PHA synthase (phaC) gene of isolated colonies. The new primers demonstrated higher sensitivity for phaC, and combining the PCR results of the two primer sets was able to widen the range of detected genera and raise the sensitivity to nearly 90%. Results showed that 85.3% of the identified bacteria were Gram-negative, with Ralstonia as the dominant genus, and 14.7% were Gram-positive. In addition, Zoogloea and Rhizobium contained the highest amounts of intracellular PHA. It is apparent that glucose was a better carbon source than pentone or tryptone for promoting PHA production in Micrococcus. Two different classes, class I and class II, of phaC were detected from alphaproteobacteria, betaproteobacteria, and gammaproteobacteria, indicating the wide diversity of PHA-accumulating bacteria in this particular sampling site. Simultaneous wastewater treatment and PHA production is promising by adopting the high PHA-accumulating bacteria isolated from activated sludge.
Performance and Spatial Succession of a Full-Scale Anaerobic Plant Treating High-Concentration Cassava Bioethanol Wastewater
Gao, Ruifang ; Yuan, Xufeng ; Li, Jiajia ; Wang, Xiaofen ; Cheng, Xu ; Zhu, Wanbin ; Cui, Zongjun ;
Journal of Microbiology and Biotechnology, volume 22, issue 8, 2012, Pages 1148~1154
DOI : 10.4014/jmb.1202.02015
A novel two-phase anaerobic treatment technology was developed to treat high-concentration organic cassava bioethanol wastewater. The start-up process and contribution of organics (COD, total nitrogen, and
-N) removal in spatial succession of the whole process and spatial microbial diversity changing when sampling were analyzed. The results of the start-up phase showed that the organic loading rate could reach up to
, with the COD removal rate remaining over 90% after 25 days. The sample results indicated that the contribution of COD removal in the pre-anaerobic and anaerobic phases was 40% and 60%, respectively, with the highest efficiency of 98.5%; TN and
-N had decreased to 0.05 g/l and 0.90 g/l, respectively, and the mineralization rate of total nitrogen was 94.8%, 76.56% of which was attributed to the anaerobic part. The microbial diversity changed remarkably among different sample points depending on the physiological characteristics of identified strains. Moraxellaceae, Planococcaceae, and Prevotellaceae were dominant in the pre-anaerobic phase and Bacteroidetes, Campylobacterales, Acinetobacter, Lactobacillus, Clostridium, and Bacillus for the anaerobic phase. Methanosarcinaceae and Methanosaeta were the two main phylotypes in the anaerobic reactor.
Influence of Reactive Media Composition and Chemical Oxygen Demand as Methanol on Autotrophic Sulfur Denitrification
Qambrani, Naveed Ahmed ; Oh, Sang-Eun ;
Journal of Microbiology and Biotechnology, volume 22, issue 8, 2012, Pages 1155~1160
DOI : 10.4014/jmb.1202.01058
Sulfur-utilizing autotrophic denitrification relies on an inorganic carbon source to reduce the nitrate by producing sulfuric acid as an end product and can be used for the treatment of wastewaters containing high levels of nitrates. In this study, sulfur-denitrifying bacteria were used in anoxic batch tests with sulfur as the electron donor and nitrate as the electron acceptor. Various medium components were tested under different conditions. Sulfur denitrification can drop the medium pH by producing acid, thus stopping the process half way. To control this mechanism, a 2:1 ratio of sulfur to oyster shell powder was used. Oyster shell powder addition to a sulfur-denitrifying reactor completely removed the nitrate. Using 50, 100, and 200 g of sulfur particles, reaction rate constants of 5.33, 6.29, and
were obtained, respectively; and using 200 g of sulfur particles showed the highest nitrate removal rates. For different sulfur particle sizes ranging from small (0.85-2.0 mm), medium (2.0-4.0 mm), and large (4.0-4.75 mm), reaction rate constants of 31.56, 10.88, and
were calculated. The fastest nitrate removal rate was observed for the smallest particle size. Addition of chemical oxygen demand (COD), methanol as the external carbon source, with the autotrophic denitrification in sufficiently alkaline conditions, created a balance between heterotrophic denitrification (which raises the pH) and sulfur-utilizing autotrophic denitrification, which lowers the pH.
Effect of Cordycepin Purified from Cordyceps militaris on Th1 and Th2 Cytokines in Mouse Splenocytes
Jeong, Min-Ho ; Seo, Min Jeong ; Park, Jeong Uck ; Kang, Byoung Won ; Kim, Kyoung-Sook ; Lee, Jae Yun ; Kim, Gi-Young ; Kim, Jung-In ; Choi, Yung Hyun ; Kim, Kwang Hyuk ; Jeong, Yong Kee ;
Journal of Microbiology and Biotechnology, volume 22, issue 8, 2012, Pages 1161~1164
DOI : 10.4014/jmb.1203.03039
Cordycepin was purified from a mushroom, Cordyceps militaris, and its effect on Th1 and Th2 cytokines was examined. The level of cytokine induction in mouse splenocytes was estimated after co-inoculation of purified cordycepin and LPS. When
of purified cordycepin was exposed to mouse splenocytes for 72 h, the level of a Th1 cytokine IL-12 increased by 2.9-fold. The addition of the purified cordycepin to splenocytes also increased the level of Th2 cytokines, IL-4 and IL-10, by 1.9- and 1.8-fold, respectively. Therefore, cordycepin increases the cytokine levels and may contribute to the up-regulation of cellular and humoral immunity.
Comparison of Molecular Assays for the Rapid Detection and Simultaneous Subtype Differentiation of the Pandemic Influenza A (H1N1) 2009 Virus
Lee, Mi Kyung ; Kim, Hye Ryoun ;
Journal of Microbiology and Biotechnology, volume 22, issue 8, 2012, Pages 1165~1169
DOI : 10.4014/jmb.1107.07061
In April 2009, the H1N1 pandemic influenza virus emerged as a novel influenza virus. The aim of this study was to compare the performances of several molecular assays, including conventional reverse transcription polymerase chain reaction (RT-PCR), two real-time reverse transcription (rRT)-PCRs, and two multiplex RTPCRs. A total of 381 clinical specimens were collected from patients (223 men and 158 women), and both the Seeplex RV7 assay and rRT-PCR were ordered on different specimens within one week after collection. The concordance rate for the two methods was 87% (332/381), and the discrepancy rate was 13% (49/381). The positive rates for the molecular assays studied included 93.1% for the multiplex Seeplex RV7 assay, 93.1% for conventional reverse transcription (cRT)-PCR, 89.7% for the multiplex Seeplex Flu ACE Subtyping assay, 82.8% for protocol B rRT-PCR, and 58.6% for protocol A rRT-PCR. Our results showed that the multiplex Seeplex assays and the cRT-PCR yielded higher detection rates than rRT-PCRs for detecting the influenza A (H1N1) virus. Although the multiplex Seeplex assays had the advantage of simultaneous detection of several viruses, they were time-consuming and troublesome. Our results show that, although rRT-PCR had the advantage, the detection rates of the molecular assays varied depending upon the source of the influenza A (H1N1)v virus. Our findings also suggest that rRT-PCR sometimes detected virus in extremely low abundance and thus required validation of analytical performance and clinical correlation.
-Cyperone Alleviates Lung Cell Injury Caused by Staphylococcus aureus via Attenuation of
Luo, M. ; Qiu, J. ; Zhang, Y. ; Wang, J. ; Dong, J. ; Li, H. ; Leng, B. ; Zhang, Q. ; Dai, X. ; Niu, X. ; Zhao, S. ; Deng, X. ;
Journal of Microbiology and Biotechnology, volume 22, issue 8, 2012, Pages 1170~1176
DOI : 10.4014/jmb.1202.02017
In this study, we aimed to evaluate the effect of
-cyperone on S. aureus. We used a hemolysin test to examine the hemolytic activity in supernatants of S. aureus cultured with increasing concentrations of
-cyperone. In addition, we evaluated the production of
-hemolysin (Hla) by Western blotting. Real-time RT-PCR was performed to test the expression of hla (the gene encoding Hla) and agr (accessory gene regulator). Furthermore, we investigated the protective effect of
-cyperone on Hla-induced injury of A549 lung cells by live/dead and cytotoxicity assays. We showed that in the presence of subinhibitory concentrations of
-cyperone, Hla production was markedly inhibited. Moreover,
-cyperone protected lung cells from Hla-induced injury. These findings indicate that
-cyperone is a promising inhibitor of Hla production by S. aureus and protects lung cells from this bacterium. Thus,
-cyperone may provide the basis for a new strategy to combat S. aureus pneumonia.