Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of Microbiology and Biotechnology
Journal Basic Information
Journal DOI :
The Korean Society for Applied Microbiology and Biotechnology
Editor in Chief :
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
Selecting the target year
Integrated Management of Foot Rot of Lentil Using Biocontrol Agents under Field Condition
Hannan, M.A. ; Hasan, M.M. ; Hossain, I. ; Rahman, S.M.E. ; Ismail, Alhazmi Mohammed ; Oh, Deog-Hwan ;
Journal of Microbiology and Biotechnology, volume 22, issue 7, 2012, Pages 883~888
DOI : 10.4014/jmb.1201.01008
The efficacy of cowdung, Bangladesh Institute of Nuclear Agriculture (BINA)-biofertilizer, and Bangladesh Agricultural University (BAU)-biofungicide, alone or in combination, was evaluated for controlling foot rot disease of lentil. The results exhibited that BINA-biofertilizer and BAU-biofungicide (peat soil-based Rhizobium leguminosarum and black gram bran-based Trichoderma harzianum) are compatible and have combined effects in controlling the pathogenic fungi Fusarium oxysporum and Sclerotium rolfsii, which cause the root rot of lentil. Cowdung mixing with soil (at 5 t/ha) during final land preparation and seed coating with BINA-biofertilizer and BAU-biofungicide (at 2.5% of seed weight) before sowing recorded 81.50% field emergence of lentil, which showed up to 19.85% higher field emergence over the control. Post-emergence deaths of plants due to foot rot disease were significantly reduced after combined seed treatment with BINA-biofertilizer and BAU-biofungicide. Among the treatments used, only BAU-biofungicide as the seed treating agent resulted in higher plant stand (84.82%). Use of BINA-biofertilizer and BAU-biofungicide as seed treating biocontrol agents and application of cowdung in the soil as an organic source of nutrient resulted in higher shoot and root lengths, and dry shoot and root weights of lentil. BINA-biofertilizer significantly increased the number of nodules per plant and nodules weight of lentil. Seeds treating with BAU-biofungicide and BINA-biofertilizer and soil amendment with cowdung increased the biomass production of lentil up to 75.56% over the control.
The Magas1 Gene is Involved in Pathogenesis by Affecting Penetration in Metarhizium acridum
Cao, Yueqing ; Zhu, Xiangxian ; Jiao, Run ; Xia, Yuxian ;
Journal of Microbiology and Biotechnology, volume 22, issue 7, 2012, Pages 889~893
DOI : 10.4014/jmb.1111.11055
Appressorium is a specialized infection structure of filamentous pathogenic fungi and plays an important role in establishing a pathogenic relationship with the host. The Egh16/Egh16H family members are involved in appressorium formation and pathogenesis in pathogenic filamentous fungi. In this study, a homolog of Egh16H, Magas1, was identified from an entomopathogenic fungus, Metarhizium acridum. The Magas1 protein shared a number of conserved motifs with other Egh16/Egh16H family members and specifically expressed during the appressorium development period. Magas1-EGFP fusion expression showed that Magas1 protein was not localized inside the cell. Deletion of the Magas1 gene had no impact on vegetative growth, conidiation and appressorium formation, but resulted in a decreased mortality of host insect when topically inoculated. However, the mortality was not significant between the Magas1 deletion mutant and wild-type treatment when the cuticle was bypassed by injecting conidia directly into the hemocoel. Our results suggested that Magas1 may influence virulence by affecting the penetration of the insects' cuticle.
Construction of Novel Bifunctional Chimeric Proteins Possessing Antitumor and Thrombolytic Activities
Hui, Jing ; Dai, Youjin ; Bian, Yuanyuan ; Li, Hui ; Cui, Xiaojin ; Yu, Xiaojie ; You, Song ; Hu, Fengqing ;
Journal of Microbiology and Biotechnology, volume 22, issue 7, 2012, Pages 894~901
DOI : 10.4014/jmb.1107.07057
Based on their respective antitumor and thrombolytic activities, the superantigen staphylococcal enterotoxin C2 (SEC2) and staphylokinase (Sak) were chosen for the construction of the novel chimeric proteins Sak-linker-SEC2 and SEC2-linker-Sak using a linker composed of nine Ala residues. Both chimeric proteins possessed nearly the same PBMC proliferation stimulating activity and antitumor activity as SEC2 and thrombolytic activity as Sak. Neither the SEC2 or Sak component of each chimeric protein affected the activity of the other component. The results presented in this study provide a possible strategy to prevent and cure tumor thrombus.
Analysis of Expressed Sequence Tags from the Antarctic Psychrophilic Green Algae, Pyramimonas gelidicola
Jung, Woongsic ; Lee, Sung Gu ; Kang, Se Won ; Lee, Yong Seok ; Lee, Jun Hyuck ; Kang, Sung-Ho ; Jin, Eon Seon ; Kim, Hak Jun ;
Journal of Microbiology and Biotechnology, volume 22, issue 7, 2012, Pages 902~906
DOI : 10.4014/jmb.1201.01002
Expressed sequence tags (ESTs) from the Antarctic green algae Pyramimonas gelidicola were analyzed to obtain molecular information on cold acclimation of psychrophilic microorganisms. A total of 2,112 EST clones were sequenced, generating 222 contigs and 219 singletons, and 200 contigs and 391 singletons from control (
) and cold-shock conditions (
), respectively. The complete EST sequences were deposited to the DDBJ EST database (http://www.ddbj.nig.ac.jp/index-e.html) and the nucleotide sequences reported in this study are available in the DDBJ/EMBL/GenBank. These EST databases of Antarctic green algae can be used in a wide range of studies on psychrophilic genes expressed by polar microorganisms.
Flagellin Administration Protects Respiratory Tract from Burkholderia cepacia Infection
Zgair, Ayaid Khadem ;
Journal of Microbiology and Biotechnology, volume 22, issue 7, 2012, Pages 907~916
DOI : 10.4014/jmb.1112.11079
Burkholderia cepacia is an important pathogen that often causes pneumonia in immunocompromised individuals. Here, it was demonstrated that the TLR5 agonist flagellin could locally activate innate immunity. This was characterized by rapid expressions of IL-
, and iNOS mRNA and a delay in the expression of IL-10 mRNA. A significant elevation in the IL-
, and nitric oxide levels was also noted. In the respiratory tract, flagellin induced neutrophil infiltration into the airways, which was observed by histopathological examination and confirmed by the neutrophil count and level of myeloperoxidase activity. This was concomitant with a high activity of alveolar macrophages that engulfed and killed B. cepacia in vitro. The flagellin mucosal treatment improved the B. cepacia clearance in the mouse lung. Thus, the present findings illustrate the profound stimulatory effect of flagellin on the lung mucosal innate immunity, a response that needs to be exploited therapeutically to prevent the development of respiratory tract infection by B. cepacia.
Homology Modeling and Docking Studies of Streptomyces peucetius CYP147F1 as Limonene Hydroxylase
Bhattarai, Saurabh ; Liou, Kwangkyoung ; Oh, Tae-Jin ;
Journal of Microbiology and Biotechnology, volume 22, issue 7, 2012, Pages 917~922
DOI : 10.4014/jmb.1112.12053
Homology modeling of Streptomyces peucetius CYP147F1 was constructed using three cytochrome P450 structures, CYP107L1, CYPVdh, and CYPeryF, as templates. The lowest energy SPCYP147F1 model was then assessed for stereochemical quality and side-chain environment by Accelrys Discovery Studio 3.1 software. Further activesite optimization of the SPCYP147F1 was performed by molecular dynamics to generate the final SPCYP147F1 model. The substrate limonene was then docked into the model. The model-limonene complex was used to validate the active-site architecture, and functionally important residues within the substrate recognition site were identified by subsequent characterization of the secondary structure. The docking of limonene suggested that SPCYP147F1 would have broad specificity with the ligand based on the two different orientations of limonene within the active site facing to the heme. Limonene with C7 facing the heme with distance of
from the Fe was predominant.
Optimization of Culture Conditions and Bench-Scale Production of
-Asparaginase by Submerged Fermentation of Aspergillus terreus MTCC 1782
Gurunathan, Baskar ; Sahadevan, Renganathan ;
Journal of Microbiology and Biotechnology, volume 22, issue 7, 2012, Pages 923~929
DOI : 10.4014/jmb.1112.12002
Optimization of culture conditions for L-asparaginase production by submerged fermentation of Aspergillus terreus MTCC 1782 was studied using a 3-level central composite design of response surface methodology and artificial neural network linked genetic algorithm. The artificial neural network linked genetic algorithm was found to be more efficient than response surface methodology. The experimental
-asparaginase activity of 43.29 IU/ml was obtained at the optimum culture conditions of temperature
, initial pH 6.3, inoculum size 1% (v/v), agitation rate 140 rpm, and incubation time 58.5 h of the artificial neural network linked genetic algorithm, which was close to the predicted activity of 44.38 IU/ml. Characteristics of
-asparaginase production by A. terreus MTCC 1782 were studied in a 3 L bench-scale bioreactor.
Isolation, Purification, and Characterization of a Thermostable Xylanase from a Novel Strain, Paenibacillus campinasensis G1-1
Zheng, Hongchen ; liu, Yihan ; Liu, Xiaoguang ; Wang, Jianling ; Han, Ying ; Lu, Fuping ;
Journal of Microbiology and Biotechnology, volume 22, issue 7, 2012, Pages 930~938
DOI : 10.4014/jmb.1110.10060
High levels of xylanase activity (143.98 IU/ml) produced by the newly isolated Paenibacillus campinasensis G1-1 were detected when it was cultivated in a synthetic medium. A thermostable xylanase, designated XynG1-1, from P. campinasensis G1-1 was purified to homogeneity by Octyl-Sepharose hydrophobic-interaction chromatography, Sephadex G75 gel-filter chromatography, and Q-Sepharose ion-exchange chromatography, consecutively. By multistep purification, the specific activity of XynG1-1 was up to 1,865.5 IU/mg with a 9.1-fold purification. The molecular mass of purified XynG1-1 was about 41.3 kDa as estimated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Sequence analysis revealed that XynG1-1 containing 377 amino acids encoded by 1,134 bp genomic sequences of P. campinasensis G1-1 shared 96% homology with XylX from Paenibacillus campinasensis BL11 and 77%~78% homology with xylanases from Bacillus sp. YA-335 and Bacillus sp. 41M-1, respectively. The activity of XynG1-1 was stimulated by
, DTT, and
-mercaptoethanol, but was inhibited by
, SDS, and EDTA. The purified XynG1-1 displayed a greater affinity for birchwood xylan, with an optimal temperature of
and an optimal pH of 7.5. The fact that XynG1-1 is cellulose-free, thermostable (stability at high temperature of
), and active over a wide pH range (pH 5.0~9.0) suggests that the enzyme is potentially valuable for various industrial applications, especially for pulp bleaching pretreatment.
Enhanced Antibiotic Production by Streptomyces sindenensis Using Artificial Neural Networks Coupled with Genetic Algorithm and Nelder-Mead Downhill Simplex
Tripathi, C.K.M. ; Khan, Mahvish ; Praveen, Vandana ; Khan, Saif ; Srivastava, Akanksha ;
Journal of Microbiology and Biotechnology, volume 22, issue 7, 2012, Pages 939~946
DOI : 10.4014/jmb.1109.09018
Antibiotic production with Streptomyces sindenensis MTCC 8122 was optimized under submerged fermentation conditions by artificial neural network (ANN) coupled with genetic algorithm (GA) and Nelder-Mead downhill simplex (NMDS). Feed forward back-propagation ANN was trained to establish the mathematical relationship among the medium components and length of incubation period for achieving maximum antibiotic yield. The optimization strategy involved growing the culture with varying concentrations of various medium components for different incubation periods. Under non-optimized condition, antibiotic production was found to be
, which nearly doubled (
) with the ANN-GA optimization. ANN-NMDS optimization was found to be more efficacious, and maximum antibiotic production (
) was obtained by cultivating the cells with (g/l) fructose 2.7602,
0.2742, DL-threonine 3.069%, and soyabean meal 1.952%, for 9.8531 days of incubation, which was roughly 12% higher than the yield obtained by ANN coupled with GA under the same conditions.
Bioconversion of Isoflavones and the Probiotic Properties of the Electroporated Parent and Subsequent Three Subcultures of Lactobacillus fermentum BT 8219 in Biotin-Soymilk
Ewe, Joo-Ann ; Wan-Abdullah, Wan-Nadiah ; Alias, Abdul Karim ; Liong, Min-Tze ;
Journal of Microbiology and Biotechnology, volume 22, issue 7, 2012, Pages 947~959
DOI : 10.4014/jmb.1112.12044
This study was aimed at an evaluation of the potential inheritance of electroporation effects on Lactobacillus fermentum BT 8219 through to three subsequent subcultures, based on their growth, isoflavone bioconversion activities, and probiotic properties, in biotin-supplemented soymilk. Electroporation was seen to cause cell death immediately after treatment, followed by higher growth than the control during fermentation in biotin-soymilk (P<0.05). This was associated with enhanced intracellular and extracellular
-glucosidase specific activity, leading to increased bioconversion of isoflavone glucosides to aglycones (P<0.05). The growing characteristics, enzyme, and isoflavone bioconversion activities of the first, second, and third subcultures of treated cells in biotin-soymilk were similar to the control (P>0.05). Electroporation affected the probiotic properties of parent L. fermentum BT 8219, by reducing its tolerance towards acid (pH 2) and bile, lowering its inhibitory activities against selected pathogens, and reducing its ability for adhesion, when compared with the control (P<0.05). The first, second, and third subcultures of the treated cells showed comparable traits with that of the control (P>0.05), with the exception of their bile tolerance ability, which was inherited to the treated cells of the first and second subcultures (P<0.05). Our results suggest that electroporation could be used to increase the bioactivity of biotin-soymilk via fermentation with probiotic L. fermentum BT 8219, with a view towards the development of functional foods.
Evaluation of Yeast Diversity During Wine Fermentations with Direct Inoculation and pied de cuve Method at an Industrial Scale
Li, Erhu ; Liu, Chuanhe ; Liu, Yanlin ;
Journal of Microbiology and Biotechnology, volume 22, issue 7, 2012, Pages 960~966
DOI : 10.4014/jmb.1111.11013
The diversity and composition of yeast populations may greatly impact wine quality. This study investigated the yeast microbiota in two different types of wine fermentations: direct inoculation of a commercial starter versus pied de cuve method at an industrial scale. The pied de cuve fermentation entailed growth of the commercial inoculum used in the direct inoculation fermentation for further inoculation of additional fermentations. Yeast isolates were collected from different stages of wine fermentation and identified to the species level using Wallersterin Laboratory nutrient (WLN) agar followed by analysis of the 26S rDNA D1/D2 domain. Genetic characteristics of the Saccharomyces cerevisiae strains were assessed by a rapid PCR-based method, relying on the amplification of interdelta sequences. A total of 412 yeast colonies were obtained from all fermentations and eight different WL morphotypes were observed. Non-Saccharomyces yeast mainly appeared in the grape must and at the early stages of wine fermentation. S. cerevisiae was the dominant yeast species using both fermentation techniques. Seven distinguishing interdelta sequence patterns were found among S. cerevisiae strains, and the inoculated commercial starter, AWRI 796, dominated all stages in both direct inoculation and pied de cuve fermentations. This study revealed that S. cerevisiae was the dominant species and an inoculated starter could dominate fermentations with the pied de cuve method under controlled conditions.
An Optical-Density-Based Feedback Feeding Method for Ammonium Concentration Control in Spirulina platensis Cultivation
Bao, Yilu ; Wen, Shumei ; Cong, Wei ; Wu, Xia ; Ning, Zhengxiang ;
Journal of Microbiology and Biotechnology, volume 22, issue 7, 2012, Pages 967~974
DOI : 10.4014/jmb.1112.12061
Cultivation of Spirulina platensis using ammonium salts or wastewater containing ammonium as alternative nitrogen sources is considered as a commercial way to reduce the production cost. In this research, by analyzing the relationship between biomass production and ammonium-N consumption in the fed-batch culture of Spirulina platensis using ammonium bicarbonate as a nitrogen nutrient source, an online adaptive control strategy based on optical density (OD) measurements for controlling ammonium feeding was presented. The ammonium concentration was successfully controlled between the cell growth inhibitory and limiting concentrations using this OD-based feedback feeding method. As a result, the maximum biomass concentration (2.98 g/l), productivity (0.237 g/l d), nitrogen-to-cell conversion factor (7.32 gX/gN), and contents of protein (64.1%) and chlorophyll (13.4mg/g) obtained by using the OD-based feedback feeding method were higher than those using the constant and variable feeding methods. The OD-based feedback feeding method could be recognized as an applicable way to control ammonium feeding and a benefit for Spirulina platensis cultivations.
Development of Monacolin K-Enriched Ganghwayakssuk (Artemisia princeps Pamp.) by Fermentation with Monascus pilosus
Lee, Dong Sub ; Lee, Inhyung ;
Journal of Microbiology and Biotechnology, volume 22, issue 7, 2012, Pages 975~980
DOI : 10.4014/jmb.1201.01016
Monacolin K-enriched ganghwayakssuk (Artemisia princeps Pamp.) was developed by fermentation with Monascus sp. Among the 15 Monascus spp. isolated previously from Monascus fermentation products, Monascus pilosus KMU108 produced 2,219 mg/kg of monacolin K during ganghwayakssuk fermentation with no detectable citrinin. The optimum concentrations of ganghwayakssuk and glucose determined from the response surface methodology (RSM) design were 2.2% and 3.8%, respectively. By applying these conditions, the monacolin K productivity was increased to 3,007 mg/kg after 15 days of fermentation. On the other hand, other characteristics such as the total content of flavonoids and phenolic compounds, and the antioxidant activity were relatively unchanged. Therefore, Monascus-fermented ganghwayakssuk is an excellent biomaterial for the development of functional foods because of its high level of monacolin K, known to lower cholesterol levels.
Growth Properties and Cholesterol Removal Ability of Electroporated Lactobacillus acidophilus BT 1088
Lye, H.S. ; Khoo, B.Y. ; Karim, A.A. ; Rusul, G. ; Liong, M.T. ;
Journal of Microbiology and Biotechnology, volume 22, issue 7, 2012, Pages 981~989
DOI : 10.4014/jmb.1201.12073
This study aimed to evaluate the effects of electroporation on the cell growth, cholesterol removal, and adherence abilities of L. acidophilus BT 1088 and their subsequent passages. The growth of electroporated parent cells increased (P<0.05) by 4.49-21.25% compared with that of the control. This may be attributed to the alteration of cellular membrane. However, growth of first, second, and third passages of treated cells was comparable with that of the control, which may be attributed to the resealing of transient pores on the cellular membrane. Electroporation also increased (P<0.05) assimilation of cholesterol by treated parent cells (>185.40%) and first passage (>21.72%) compared with that of the control. Meanwhile, incorporation of cholesterol into the cellular membrane was also increased (P<0.05) in the treated parent cells (>108.33%) and first passage (>26.67%), accompanied by increased ratio of cholesterol:phospholipids (C:P) in these passages. Such increased ratio was also supported by increased enrichment of cholesterol in the hydrophilic heads, hydrophobic tails, and the interface regions of the membrane phospholipids of both parent and first passage cells compared with that of the control. However, such traits were not inherited by the subsequent second and third passages. Parent cells also showed decreased intestinal adherence ability (P<0.05; decreased by 1.45%) compared with that of the control, without inheritance by subsequent passages of treated cells. Our data suggest that electoporation could be a potential physical treatment to enhance the cholesterol removal ability of lactobacilli that was inherited by the first passage of treated cells without affecting their intestinal adherence ability.
Improved Production of Long-Chain Fatty Acid in Escherichia coli by an Engineering Elongation Cycle During Fatty Acid Synthesis (FAS) Through Genetic Manipulation
Jeon, Eunyoung ; Lee, Sunhee ; Lee, Seunghan ; Han, Sung Ok ; Yoon, Yeo Joon ; Lee, Jinwon ;
Journal of Microbiology and Biotechnology, volume 22, issue 7, 2012, Pages 990~999
DOI : 10.4014/jmb.1112.12057
The microbial biosynthesis of fatty acid of lipid metabolism, which can be used as precursors for the production of fuels of chemicals from renewable carbon sources, has attracted significant attention in recent years. The regulation of fatty acid biosynthesis pathways has been mainly studied in a model prokaryote, Escherichia coli. During the recent period, global regulation of fatty acid metabolic pathways has been demonstrated in another model prokaryote, Bacillus subtilis, as well as in Streptococcus pneumonia. The goal of this study was to increase the production of long-chain fatty acids by developing recombinant E. coli strains that were improved by an elongation cycle of fatty acid synthesis (FAS). The fabB, fabG, fabZ, and fabI genes, all homologous of E. coli, were induced to improve the enzymatic activities for the purpose of overexpressing components of the elongation cycle in the FAS pathway through metabolic engineering. The
-oxoacyl-ACP synthase enzyme catalyzed the addition of acyl-ACP to malonyl-ACP to generate
-oxoacyl-ACP. The enzyme encoded by the fabG gene converted
-hydroxyacyl-ACP, the fabZ catalyzed the dehydration of
-3-hydroxyacyl-ACP to trans-2-acyl-ACP, and the fabI gene converted trans-2-acyl-ACP to acyl-ACP for long-chain fatty acids. In vivo productivity of total lipids and fatty acids was analyzed to confirm the changes and effects of the inserted genes in E. coli. As a result, lipid was increased 2.16-fold higher and hexadecanoic acid was produced 2.77-fold higher in E. coli JES1030, one of the developed recombinants through this study, than those from the wild-type E. coli.
Production of Platinum Nanoparticles and Nanoaggregates Using Neurospora crassa
Castro-Longoria, E. ; Moreno-Velasquez, S.D. ; Vilchis-Nestor, A.R. ; Arenas-Berumen, E. ; Avalos-Borja, M. ;
Journal of Microbiology and Biotechnology, volume 22, issue 7, 2012, Pages 1000~1004
DOI : 10.4014/jmb.1110.10085
Fungal biomass and fungal extract of the nonpathogenic fungus Neurospora crassa were successfully used as reducing agents for the biosynthesis of platinum nanoparticles (PtNPs). The experiment was carried out by exposing the fungal biomass or the fungal extract to a 0.001 M precursor solution of hexachloroplatinic(IV) acid (
). A change of color of the biomass from pale yellow to dark brown was the first indication of possible formation of PtNPs by the fungus. Subsequent analyses confirmed the intracellular biosynthesis of single PtNPs (4-35 nm in diameter) and spherical nanoaggregates (20-110 nm in diameter). Using the fungal extract, similar results were obtained, producing rounded nanoaggregates of Pt single crystals in the range of 17-76 nm.
Changes in the Ammonia-Oxidizing Bacteria Community in Response to Operational Parameters During the Treatment of Anaerobic Sludge Digester Supernatant
Cydzik-Kwiatkowska, Agnieszka ; Zielinska, Magdalena ; Bernat, Katarzyna ; Kulikowska, Dorota ; Wojnowska-Baryla, Irena ;
Journal of Microbiology and Biotechnology, volume 22, issue 7, 2012, Pages 1005~1014
DOI : 10.4014/jmb.1111.11011
The understanding of the relationship between ammonia-oxidizing bacteria (AOB) communities in activated sludge and the operational treatment parameters supports the control of the treatment of ammonia-rich wastewater. The modifications of treatment parameters by alteration of the number and length of aerobic and anaerobic stages in the sequencing batch reactor (SBR) working cycle may influence the efficiency of ammonium oxidation and induce changes in the AOB community. Therefore, in the research, the impact of an SBR cycle mode with alternating aeration/mixing conditions (7 h/1 h vs. 4 h/5.5 h) and volumetric exchange rate (n) on AOB abundance and diversity in activated sludge during the treatment of anaerobic sludge digester supernatant at limited oxygen concentration in the aeration stage (0.7 mg
) was assessed. AOB diversity expressed by the Shannon-Wiener index (H') was determined by the cycle mode. At aeration/mixing stage lengths of 7 h/1 h, H' averaged
, while at 4 h/5.5 h it was
. At the given mode, AOB diversity decreased with increasing n. The cycle mode did not affect AOB abundance; however, a higher AOB abundance in activated sludge was promoted by decreasing the volumetric exchange rate. The sequences clustering with Nitrosospira sp. NpAV revealed the uniqueness of the AOB community and the simultaneously lower ability of adaptation of Nitrosospira sp. to the operational parameters applied in comparison with Nitrosomonas sp.
Application of Antifungal CFB to Increase the Durability of Cement Mortar
Park, Jong-Myong ; Park, Sung-Jin ; Kim, Wha-Jung ; Ghim, Sa-Youl ;
Journal of Microbiology and Biotechnology, volume 22, issue 7, 2012, Pages 1015~1020
DOI : 10.4014/jmb.1112.12027
Antifungal cement mortar or microbiological calcium carbonate precipitation on cement surface has been investigated as functional concrete research. However, these research concepts have never been fused with each other. In this study, we introduced the antifungal calcite-forming bacteria (CFB) Bacillus aryabhattai KNUC205, isolated from an urban tunnel (Daegu, South Korea). The major fungal deteriogens in urban tunnel, Cladosporium sphaerospermum KNUC253, was used as a sensitive fungal strain. B. aryabhattai KNUC205 showed
precipitation on B4 medium. Cracked cement mortar pastes were made and neutralized by modified methods. Subsequently, the mixture of B. aryabhattai KNUC205, conidiospore of C. sphaerospermum KNUC253, and B4 agar was applied to cement cracks and incubated at
for 16 days. B. aryabhattai KNUC205 showed fungal growth inhibition against C. sphaerospermum. Furthermore, B. aryabhattai KNUC205 showed crack remediation ability and water permeability reduction of cement mortar pastes. Taken together, these results suggest that the
precipitation and antifungal properties of B. aryabhattai KNUC205 could be used as an effective sealing or coating material that can also prevent deteriorative fungal growth. This study is the first application and evaluation research that incorporates calcite formation with antifungal capabilities of microorganisms for an environment-friendly and more effective protection of cement materials. In this research, the conception of microbial construction materials was expanded.
Development of a Reverse Transcription Loop-Mediated Isothermal Amplification Assay for Detecting Nervous Necrosis Virus in Olive Flounder Paralichthys olivaceus
Suebsing, Rungkarn ; Oh, Myung-Joo ; Kim, Jeong-Ho ;
Journal of Microbiology and Biotechnology, volume 22, issue 7, 2012, Pages 1021~1028
DOI : 10.4014/jmb.1201.01005
In this study, a reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for the rapid, sensitive, and inexpensive detection of nervous necrosis virus (NNV) in olive flounder, Paralichthys olivaceus, in Korea. A set of six specific primers was designed to target the RNA 2 gene encoding the coat protein of Korean NNV strains. The RT-LAMP reaction successfully detected NNV after 30 min at
. When the sensitivities among RT-LAMP, RT-PCR, and nested RTPCR were compared, the RT-LAMP was shown to be able to detect the RNA template at
, whereas the RT-PCR and nested RT-PCR were only able to detect the RNA template at
, respectively. Thus, the sensitivity of the RT-LAMP assay was higher than those of the RT-PCR assays. In the specificity test of the RT-LAMP, 2 genotypes of NNVs (SJNNV and RGNNV) were positive; however, no other fish viruses were positive with the primers, indicating that the RT-LAMP assay is only specific to NNV. A total of 102 olive flounder were collected from hatcheries between 2009 and 2011. The occurrence of NNV in olive flounder was determined to be 53.9% (55/102) by the RT-LAMP. On the other hand, the prevalence based on the nested RT-PCR and RT-PCR results was 33.8% (34/102) and 20.6% (21/102), respectively. This result indicates that the RT-LAMP assay developed in this study is suitable for early field diagnosis of NNV with high sensitivity.
Protein Tyrosine Phosphatase Profiling Analysis of HIB-1B Cells during Brown Adipogenesis
Choi, Hye-Ryung ; Kim, Won Kon ; Kim, Eun Young ; Jung, Hyeyun ; Kim, Jeong-Hoon ; Han, Baek-Soo ; You, Kwan-Hee ; Lee, Sang Chul ; Bae, Kwang-Hee ;
Journal of Microbiology and Biotechnology, volume 22, issue 7, 2012, Pages 1029~1033
DOI : 10.4014/jmb.1112.12059
A number of evidence have been accumulated that the regulation of reversible tyrosine phosphorylation, which can be regulated by the combinatorial activity of protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs), plays crucial roles in various biological processes including differentiation. There are a total of 107 PTP genes in the human genome, collectively referred to as the "PTPome." In this study, we performed PTP profiling analysis of the HIB-1B cell line, a brown preadipocyte cell line, during brown adipogenesis. Through RT-PCR and real-time PCR, several PTPs showing differential expression pattern during brown adipogenesis were identified. In the case of PTP-RE, it was shown to decrease significantly until 4 days after brown adipogenic differentiation, followed by a dramatic increase at 6 days. The overexpression of PTP-RE led to decreased brown adipogenic differentiation via reducing the tyrosine phosphorylation of the insulin receptor, indicating that PTP-RE functions as a negative regulator at the early stage of brown adipogenesis.