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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 20, Issue 12 - Dec 2010
Volume 20, Issue 11 - Nov 2010
Volume 20, Issue 10 - Oct 2010
Volume 20, Issue 9 - Sep 2010
Volume 20, Issue 8 - Aug 2010
Volume 20, Issue 7 - Jul 2010
Volume 20, Issue 6 - Jun 2010
Volume 20, Issue 5 - May 2010
Volume 20, Issue 4 - Apr 2010
Volume 20, Issue 3 - Mar 2010
Volume 20, Issue 2 - Feb 2010
Volume 20, Issue 1 - Jan 2010
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Molecular Diversity of Fungal Endophytes Isolated from Garcinia mangostana and Garcinia parvifolia
Sim, Jiun-Horng ; Khoo, Chai-Hoon ; Lee, Learn-Han ; Cheah, Yoke-Kqueen ;
Journal of Microbiology and Biotechnology, volume 20, issue 4, 2010, Pages 651~658
DOI : 10.4014/jmb.0909.09030
Garcinia is commonly found in Malaysia, but limited information is available regarding endophytic fungi associated with this plant. In this study, 24 endophytic fungi were successfully recovered from different parts of two Garcinia species. Characterization of endophytic fungi was performed based on the conserved internal transcribed spacer (ITS) region sequence analysis and the antimicrobial properties. Results revealed that fruits of the plant appeared to be the highest inhabitation site (38%) as compared with others. Glomerella sp., Guignardia sp., and Phomopsis sp. appeared to be the predominant endophytic fungi group in Garcinia mangostana and Garcinia parvifolia. Phylogenetic relationships of the isolated endophytic fungi were estimated from the sequences of the ITS region. On the other hand, antibacterial screening showed 11 of the isolates possessed positive response towards pathogenic and nonpathogenic bacteria. However, there was no direct association between certain antibacterial properties with the specific genus observed.
Molecular Cloning and Characterization of a cis-Epoxysuccinate Hydrolase from Bordetella sp. BK-52
Pan, Hai Feng ; Bao, Wen Na ; Xie, Zhi Peng ; Zhang, Jian Guo ; Li, Yongquan ;
Journal of Microbiology and Biotechnology, volume 20, issue 4, 2010, Pages 659~665
DOI : 10.4014/jmb.0905.05059
A cis-epoxysuccinate hydrolase (CESH) from Bordetella sp. BK-52 was purified 51.4-fold with a yield of 27.1% using ammonium sulfate precipitation, ionic exchange, hydrophobic interaction, molecular sieve chromatography and an additional anion-exchange chromatography. The CESH was stable in a broad range of temperature (up to
) and pH (4.0-10.0) with optima of
and pH 6.5, respectively. It could be partially inhibited by EDTA-
, SDS, and DTT, and slightly enhanced by
. The enzyme exhibited high stereospecificity in D(-)-tartaric acid (enantiomeric excess value higher than 99%) with
values of 18.67 mM and
/min/mg for disodium cis-epoxysuccinate, respectively. The Bordetella sp. BK-52 CESH gene, which contained 885 nucleotides (open reading frame) encoding 294 amino acids with a molecular mass of about 32 kDa, was successfully overexpressed in Escherichia coli using a T7/lac promoter vector and the enzyme activity was increased 42-times compared with the original strain. It may be an industrial biocatalyst for the preparation of D(-)-tartaric acid.
A Series of Vectors with Alternative Antibiotic Resistance Markers for Use in Lambda Red Recombination
Quick, Laura N. ; Shah, Ashka ; Wilson, James W. ;
Journal of Microbiology and Biotechnology, volume 20, issue 4, 2010, Pages 666~669
DOI : 10.4014/jmb.0909.09045
A target bacterial strain of interest for use in Red-based recombineering may already encode resistance to antibiotic markers used with current Red recombination tools, such that the resistance cannot be removed. Such cases include those where markers are needed to maintain an unstable genetic element co-resident in the strain or those where the genetic source of resistance is not known. We report the availability of PCR templates with FRT-flanked mutagenesis cassettes and plasmids encoding Red recombination functions that contain marker combinations not currently available on widely disseminated lambda Red molecular reagents. The functionality of these convenient alternative tools is demonstrated.
Cloning, Expression, and Characterization of a Highly Active Alkaline Pectate Lyase from Alkaliphilic Bacillus sp. N16-5
Li, Gang ; Rao, Lang ; Xue, Yanfen ; Zhou, Cheng ; Zhang, Yun ; Ma, Yanhe ;
Journal of Microbiology and Biotechnology, volume 20, issue 4, 2010, Pages 670~677
DOI : 10.4014/jmb.0911.11019
An alkaline pectate lyase, Bsp165PelA, was purified to homogeneity from the culture broth of alkaliphilic Bacillus sp. N16-5. The enzyme showed a specific activity as high as 1,000 U/mg and had optimum activity at pH 11.5 and
. It was composed of a single polypeptide chain with a molecular mass of 42 kDa deduced from SDS-PAGE, and its isoelectric point was around pH 6.0. It could efficiently depolymerize polygalacturonate and pectin. Characterization of product formation revealed unsaturated digalacturonate and trigalacturonate as the main products. The pectate lyase gene (pelA) contained an open reading frame (ORF) of 1,089 bp, encoding a 36-amino acids signal peptide and a mature protein of 326 amino acids with a calculated molecular mass of 35.943 Da. The deduced amino acid sequence from the pelA ORF exhibited significant homology to those of known pectate lyases in polysaccharide lyase family 1. Some conserved active-site amino acids were found in the deduced amino acid sequence of Bsp165PelA.
was not required for activity on pectic substrates.
Two pHZ1358 Derivative Vectors for Efficient Gene Knockout in Streptomyces
He, Yunlong ; Wang, Zhijun ; Bai, Linquan ; Liang, Jingdan ; Zhou, Xiufen ; Deng, Zixin ;
Journal of Microbiology and Biotechnology, volume 20, issue 4, 2010, Pages 678~682
DOI : 10.4014/jmb.0910.10031
The deletion of sti from the Streptomyces plasmid pIJ101 made its derivative pHZ1358 an efficient vector for gene disruption and replacement. Here, pHZ1358 was further optimized by the construction of a derivative plasmid pJTU1278, in which a cassette carrying multiple cloning sites and a lacZ selection marker were introduced for convenient plasmid construction in E. coli. In addition, the oriT region of pJTU1278 was also deleted, generating a vector (pJTU1289) that can be used specifically for PCR-targeting. The efficient usage of these vectors was demonstrated by the deletion of the gene involved in avermectin biosynthesis in S. avermitilis.
Efficiency of RAPD and ISSR Markers in Differentiation of Homo- and Heterokaryotic Protoclones of Agaricus bisporus
Mahmudul, Islam Nazrul ; Bian, Yin-Bing ;
Journal of Microbiology and Biotechnology, volume 20, issue 4, 2010, Pages 683~692
DOI : 10.4014/jmb.0906.06031
Morphologically, nine different slow-growing protoclones were screened from regenerated protoplasts of heterokaryotic Agaricus bisporus. As such, the present study is the first report on differentiating homo- and heterokaryotic protoclones using random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) markers. Among 80 primers tested, the seven ISSR and seven RAPD primers selected for the analysis generated a total of 94 ISSR and 52 RAPD fragments, respectively. The ISSR fingerprinting also detected more polymorphic loci (38.29%) than the RAPD fingerprinting (34.61%). A principal coordinate analysis (PCA) was employed to evaluate the resolving power of the markers as regards differentiating protoclones. As a result, the mean polymorphism information content (PIC) for each marker system (i.e., 0.787 for RAPD and 0.916 for ISSR) suggested that ISSR is more effective for determining polymorphisms. The dendrograms constructed using RAPD, ISSR, and an integrated RAPD and ISSR marker system were highly correlated with one another as revealed by a high Mantel correlation (r= 0.98). The pairwise similarity index values also ranged from 0.64 to 0.95 (RAPD), 0.67 to 0.98 (ISSR), and 0.67 to 0.98 (RAPD and ISSR), whereas the mean similarity index values of 0.82, 0.81, and 0.84 were obtained for the RAPD, ISSR, and combined data, respectively. As there was a good correspondence between the RAPD and ISSR similarity matrices, ISSR would appear to be an effective alternative to RAPD in the genetic diversity assessment and accurate differentiation of homo- and heterokaryotic protoclones of A. bisporus.
An Antiproliferative Ribonuclease from Fruiting Bodies of the Wild Mushroom Russula delica
Zhao, Shuang ; Zhao, Yong Chang ; Li, Shu Hong ; Zhang, Guo Qing ; Wang, He Xiang ; Ng, Tzi Bun ;
Journal of Microbiology and Biotechnology, volume 20, issue 4, 2010, Pages 693~699
DOI : 10.4014/jmb.0911.11022
An antiproliferative ribonuclease with a new N-terminal sequence was purified from fruiting bodies of the edible wild mushroom Russula delica in this study. This novel ribonuclease was unadsorbed on DEAE-cellulose, but absorbed on SP-Sepharose and Q-Sepharose. It had a molecular mass of 14 kDa, as judged by fast protein liquid chromatography on Superdex 75 and SDS-polyacrylamide gel electrophoresis. Its optimal pH and optimal temperature were pH 5 and
, respectively. The ranking of its activity toward various polyhomoribonucleotides was poly C> poly G>poly A>poly U. It could inhibit proliferation of HepG2 and MCF-7 cancer cells with an
, respectively. It was devoid of antifungal and HIV-1 reverse transcriptase inhibitory activity.
Neuroprotective Effects of a Novel Peptide Purified from Venison Protein
Kim, Eun-Kyung ; Lee, Seung-Jae ; Moon, Sang-Ho ; Jeon, Byong-Tae ; Kim, Bo-Kyung ; Park, Tae-Kyu ; Han, Ji-Sook ; Park, Pyo-Jam ;
Journal of Microbiology and Biotechnology, volume 20, issue 4, 2010, Pages 700~707
DOI : 10.4014/jmb.0909.09033
A novel antioxidative peptide (APVPH I, antioxidative peptides from venison protein hydrolysates I) was purified from venison by enzymatic hydrolysis, column chromatography of DEAE-Sephacel, and high-performance liquid chromatography. The molecular mass of the purified peptide was found to be 9,853 Da and the amino acid sequences of the purified peptide was Met-Gln-Ile-Phe-Val-Lys-Thr-Leu-Thr-Gly. The purpose of this study was to evaluate the effects of APVPH I against
-induced neuronal cells damage in PC-12 cells. Antioxidative enzyme levels in cultured neuronal cells were increased in the presence of the peptide. In addition, APVPH I inhibited productions of nitric oxide (NO), reactive oxygen species (ROS), malondialdehyde (MDA), and cell death against
-induced neuronal cell damage in PC-12 cells. It was presumed to be APVPH I involved in regulating the apoptosis-related gene expression in the cell environment. The present results indicate that APVPH I substantially contributes to antioxidative properties in neuronal cells.
Isolation and Characterization of Psacotheasin, a Novel Knottin-Type Antimicrobial Peptide, from Psacothea hilaris
Hwang, Jae-Sam ; Lee, June-Young ; Hwang, Bo-Mi ; Nam, Sung-Hee ; Yun, Eun-Young ; Kim, Seong-Ryul ; Lee, Dong-Gun ;
Journal of Microbiology and Biotechnology, volume 20, issue 4, 2010, Pages 708~711
DOI : 10.4014/jmb.1002.02003
We report the isolation and characterization of a novel knottin-type antimicrobial peptide from the yellow-spotted long-horned beetle Psacothea hilaris. A cDNA encoding a 56-mer knottin-type propeptide was identified and its predicted molecular mass and pI were 5.92 kDa and 8.28, respectively. A 34-mer mature peptide was also selected and named herein as psacotheasin. The antimicrobial activity of chemically synthesized psacotheasin against human bacterial pathogens was subsequently investigated. The results showed that psacotheasin exerted potent activities against both Gram-positive and Gram-negative bacterial strains. The present study suggests that psacotheasin can be applied to develop novel therapeutic agents.
Surface Display of Heme- and Diflavin-Containing Cytochrome P450 BM3 in Escherichia coli: A Whole-Cell Biocatalyst for Oxidation
Yim, Sung-Kun ; Kim, Dong-Hyun ; Jung, Heung-Chae ; Pan, Jae-Gu ; Kang, Hyung-Sik ; Ahn, Tae-Ho ; Yun, Chul-Ho ;
Journal of Microbiology and Biotechnology, volume 20, issue 4, 2010, Pages 712~717
DOI : 10.4014/jmb.0910.10043
Cytochrome P450 enzymes (P450s) are involved in the synthesis of a wide variety of valuable products and in the degradation of numerous toxic compounds. The P450 BM3 (CYP102A1) from Bacillus megaterium was the first P450 discovered to be fused to its redox partner, a mammalian-like diflavin reductase. Here, we report the development of a whole-cell biocatalyst using ice-nucleation protein (Inp) from Pseudomonas syringae to display a hemeand diflavin-containing oxidoreductase, P450 BM3 (a single, 119-kDa polypeptide with domains of both an oxygenase and a reductase) on the surface of Escherichia coli. The surface localization and functionality of the fusion protein containing P450 BM3 were verified by flow cytometry and measurement of enzymatic activities. The results of this study comprise the first report of microbial cell-surface display of a heme- and diflavin-containing enzyme. This system should allow us to select and develop oxidoreductases containing heme and/or flavins into practically useful whole-cell biocatalysts for extensive biotechnological applications, including selective synthesis of new chemicals and pharmaceuticals, bioconversion, bioremediation, live vaccine development, and biochip development.
Improvement of a Fungal Strain by Repeated and Sequential Mutagenesis and Optimization of Solid-State Fermentation for the Hyper-Production of Raw-Starch-Digesting Enzyme
Vu, Van Hanh ; Pham, Tuan Anh ; Kim, Keun ;
Journal of Microbiology and Biotechnology, volume 20, issue 4, 2010, Pages 718~726
DOI : 10.4014/jmb.0908.08016
A selected fungal strain, for production of the raw-starchdigesting enzyme by solid-state fermentation, was improved by two repeated sequential exposures to
, ultraviolet, and four repeated treatments with Nmethyl-N'-nitrosoguanidine. The mutant strain Aspergillus sp. XN15 was chosen after a rigorous screening process, with its production of the raw-starch-digesting enzyme being twice that of usual wild varieties cultured under preoptimized conditions and in an unsupplemented medium. After 17 successive subculturings, the enzyme production of the mutant was stable. Optimal conditions for the production of the enzyme by solid-state fermentation, using wheat bran as the substrate, were accomplished for the mutant Aspergillus sp. XN15. With the optimal fermentation conditions, and a solid medium supplemented with nitrogen sources of 1% urea and 1%
, 2.5 mM
, 0.05% (v/w) Tween 80, and 1% glucose, the mutant Aspergillus sp. XN15 produced the raw-starch-digesting enzyme in quantities 19.4 times greater than a typical wild variety. Finally, XN15, through simultaneous saccharification and fermentation of a raw rice corn starch slurry, produced a high level of ethanol with
of 0.47 g/g.
An Efficient Method for the Expression and Reconstitution of Thermostable Mn/Fe Superoxide Dismutase from Aeropyrum pernix K1
Lee, Hee-Jin ; Kwon, Hye-Won ; Koh, Jong-Uk ; Lee, Dong-Kuk ; Moon, Ja-Young ; Kong, Kwang-Hoon ;
Journal of Microbiology and Biotechnology, volume 20, issue 4, 2010, Pages 727~731
DOI : 10.4014/jmb.0911.11008
The gene APE0743 encoding the superoxide dismutase (ApSOD) of a hyperthermophilic archaeon Aeropyrum pernix K1 was cloned and overexpressed as a GST fusion protein at a high level in Escherichia coli. The expressed protein was simply purified by the process of glutathione affinity chromatography and thrombin treatment. The ApSOD was a homodimer of 25 kDa subunits and a cambialistic SOD, which was active with either Fe(II) or Mn(II) as a cofactor. The ApSOD was highly stable against high temperature. This thermostable ApSOD is expected to be applicable as a useful biocatalyst for medicine and bioindustrial processes.
Production of Novel Cell-Associated Tannase from Newly Isolated Serratia ficaria DTC
Belur, Prasanna D. ; Gopal, Mugeraya ; Nirmala, K.R. ; Basavaraj, N. ;
Journal of Microbiology and Biotechnology, volume 20, issue 4, 2010, Pages 732~736
DOI : 10.4014/jmb.0907.07033
Five strains of tannic acid degrading bacteria were isolated and identified by phenotypic characterization. All the five isolates showed cell-associated activity, whereas only three showed extracellular activity. Serratia ficaria DTC, showing the highest cell-associated activity (0.29 U/l), was selected for further shake-flask studies. Tannase synthesis was growth associated and reached the peak in the late stationary phase of growth. Organic nitrogen sources enhanced the tannase production. Peak tannase production of 0.56 U/l was recorded in the medium having the initial pH of 6. The pH and temperature optima of the enzyme were found to be 8.9 and
, respectively. This is the first report of cell-associated activity in the case of bacterial tannase. Cell-associated tannase of Serratia ficaria DTC could be industrially important from the perspective of its activity at broad temperature and pH ranges, and its unusually high activity at pH 8.9.
Production of Glutaminase (E.C. 18.104.22.168) from Zygosaccharomyces rouxii in Solid-State Fermentation and Modeling the Growth of Z. rouxii Therein
Iyer, Padma ; Singhal, Rekha S. ;
Journal of Microbiology and Biotechnology, volume 20, issue 4, 2010, Pages 737~748
DOI : 10.4014/jmb.0903.03024
Glutaminase production in Zygosaccharomyces rouxii by solid-state fermentation (SSF) is detailed. Substrates screening showed best results with oatmeal (OM) and wheatbran (WB). Furthermore, a 1:1 combination of OM:WB gave 0.614 units/gds with artificial sea water as a moistening agent. Evaluation of additional carbon, nitrogen, amino acids, and minerals supplementation was done. A central composite design was employed to investigate the effects of four variables (viz., moisture content, glucose, corn steep liquor, and glutamine) on production. A 4-fold increase in enzyme production was obtained. Studies were undertaken to analyze the time-course model, the microbial growth, and nutrient utilization during SSF. A logistic equation (
=0.8973), describing the growth model of Z. rouxii, was obtained with maximum values of
and 7.35% of dry matter weight loss, respectively. A goodfit model to describe utilization of total carbohydrate (
=0.9906) and nitrogen concentration (
=0.9869) with time was obtained. The model was used successfully to predict enzyme production (
Assessment of Bile Salt Effects on S-Layer Production, slp Gene Expression and, Some Physicochemical Properties of Lactobacillus acidophilus ATCC 4356
Khaleghi, M. ; Kermanshahi, R. Kasra ; Yaghoobi, M.M. ; Zarkesh-Esfahani, S.H. ; Baghizadeh, A. ;
Journal of Microbiology and Biotechnology, volume 20, issue 4, 2010, Pages 749~756
DOI : 10.4014/jmb.0906.06050
In many conditions, bacterial surface properties are changed as a result of variation in the growth medium and conditions. This study examined the influence of bile salt concentrations (0-0.1%) on colony morphotype, hydrophobicity,
concentration, S-layer protein production, and slpA gene expression in Lactobacillus acidophilus ATCC 4356. It was observed that two types of colonies (R and S) were in the control group and the stress condition. When the bile level increased in the medium, the amount of S type was more than the R type. A stepwise increment in the bile concentration resulted in a stepwise decline in the maximum growth rate. The results showed that hydrophobicity was increased in 0.01%-0.02% bile, but it was decreased in 0.1% bile. Treatment by bile (0.01%-0.1%) profoundly decreased
formation. S-Layer protein and slpA gene expression were also altered by the stress condition. S-Protein expression was increased in the stress condition. The slpA gene expression increased in 0.01%-0.05% bile and it decreased in 0.1% bile. However, we found that different bile salt concentrations influenced the morphology and some surface properties of L. acidophilus ATCC 4356. These changes were very different in the 0.1% bile. It appears that the bacteria respond abruptly to 0.1% bile.
Identification and Classification of Cronobacter spp. Isolated from Powdered Food in Korea
Lee, Young-Duck ; Ryu, Tae-Wha ; Chang, Hyo-Ihl ; Park, Jong-Hyun ;
Journal of Microbiology and Biotechnology, volume 20, issue 4, 2010, Pages 757~762
DOI : 10.4014/jmb.0912.12004
Cronobacter is a major foodborne pathogen in powdered infant formula and can lead to serious developmental after-effect and death to infants. The contamination of Cronobacter may be a high risk for the powdered foods. To isolate and identify Cronobacter from the powdered foods such as powdered infant formula and Saengsik in Korea, a conventional culture method, rapid identification system, PCR, and 16S rDNA sequencing were performed. As the results of isolation, seven Cronobacter spp. were isolated from seven out of 102 powdered infant formulas and 41 Cronobacter were isolated from 41 out of 86 Saengsiks. Forty-eight Cronobacter isolates were identified to be C. sakazakii and C. dublenisis by 16S rDNA sequence analysis. Most of the isolates were C. sakazakii and 13% of the isolates were C. dublinesis. One fourth of the C. sakazakii isolates showed different biochemical characteristics of negative nitrate reduction and nonmotility activities compared with the other strains reported previously.
Enhanced Production of
-Aminobutyric Acid Using Rice Bran Extracts by Lactobacillus sakei B2-16
Kook, Moo-Chang ; Seo, Myung-Ji ; Cheigh, Chan-Ick ; Pyun, Yu-Ryang ; Cho, Seok-Cheol ; Park, Hoon ;
Journal of Microbiology and Biotechnology, volume 20, issue 4, 2010, Pages 763~766
DOI : 10.4014/jmb.0911.11016
An efficient and simple fermentation process was developed for the production of
-aminobutyric acid (GABA) by Lactobacillus sakei B2-16. When the L. sakei B2-16 was cultivated in the rice bran extracts medium containing 4% sucrose, 1% yeast extract, and 12% monosodium glutamate, the maximum GABA concentration reached 660.0 mM with 100% conversion yield, showing the 2.4- fold higher GABA concentration compared with the modified MRS medium without the rice bran extracts. The GABA production was scaled-up from a laboratory scale (5 l) to a pilot (300 l) and a plant (5,000 l) scale to investigate the application possibility of GABA production to industrial fields. The production yields at the pilot and plant scales were similar to the laboratory scale using rice bran extracts medium, which could be effective for the low-cost production of GABA.
Construction of an Industrial Brewing Yeast Strain to Manufacture Beer with Low Caloric Content and Improved Flavor
Wang, Jin-Jing ; Wang, Zhao-Yue ; Liu, Xi-Feng ; Guo, Xue-Na ; He, Xiu-Ping ; Wense, Pierre Christian ; Zhang, Bo-Run ;
Journal of Microbiology and Biotechnology, volume 20, issue 4, 2010, Pages 767~774
DOI : 10.4014/jmb.0910.10013
In this study, the problems of high caloric content, increased maturation time, and off-flavors in commercial beer manufacture arising from residual sugar, diacetyl, and acetaldehyde levels were addressed. A recombinant industrial brewing yeast strain (TQ1) was generated from T1 [Lipomyces starkeyi dextranase gene (LSD1) introduced,
-acetohydroxyacid synthase gene (ILV2) disrupted] by introducing Saccharomyces cerevisiae glucoamylase (SGA1) and a strong promoter (PGK1), while disrupting the gene coding alcohol dehydrogenase (ADH2). The highest glucoamylase activity for TQ1 was 93.26 U/ml compared with host strain T1 (12.36 U/ml) and wild-type industrial yeast strain YSF5 (10.39 U/ml), respectively. European Brewery Convention (EBC) tube fermentation tests comparing the fermentation broths of TQ1 with T1 and YSF5 showed that the real extracts were reduced by 15.79% and 22.47%; the main residual maltotriose concentrations were reduced by 13.75% and 18.82%; the caloric contents were reduced by 27.18 and 35.39 calories per 12 oz. Owing to the disruption of the ADH2 gene in TQ1, the off-flavor acetaldehyde concentrations in the fermentation broth were 9.43% and 13.28%, respectively, lower than that of T1 and YSF5. No heterologous DNA sequences or drug resistance genes were introduced into TQ1. Hence, the gene manipulations in this work properly solved the addressed problems in commercial beer manufacture.
Prevalence and Characterization of Methicillin-Resistant Staphylococcus aureus in Raw Meat in Korea
Lim, Suk-Kyung ; Nam, Hyang-Mi ; Park, Hyun-Jung ; Lee, Hee-Soo ; Choi, Min-Jung ; Jung, Suk-Chan ; Lee, Ji-Yeon ; Kim, Young-Cho ; Song, Si-Wook ; Wee, Sung-Hwan ;
Journal of Microbiology and Biotechnology, volume 20, issue 4, 2010, Pages 775~778
DOI : 10.4014/jmb.0912.12022
A total of 2,858 meat samples collected during 2003-2008 in Korea were investigated, and methicillin-resistant Staphylococcus aureus (MRSA) isolates were isolated from 1.0% (9/890) of beef, 0.3% (4/1,055) of pork, and 0.3% (3/913) of chicken meat samples, respectively. MRSA isolates showed the two sequence types (STs), ST72 from beef and pork and ST692 from chicken meat. MRSA isolates from beef and pork were Panton-Valentine leukocidin-negative, staphylococcal cassette chromosome mec type IVa strain with ST72, which is the most prevalent type of communityacquired MRSA in Korea. An identical pulse-field gel electrophoresis pattern was detected among 10 of 16 MRSA isolates: 9 strains from beef (n=5) and pork (n=4) in 2008, and one strain from beef in 2005.
Heterotrophic Bacterial Growth on Hoses in a Neonatal Water Distribution System
Buffet-Bataillon, Sylvie ; Bonnaure-Mallet, Martine ; De La Pintiere, Armelle ; Defawe, Guy ; Gautier-Lerestif, Anne Lise ; Fauveau, Severine ; Minet, Jacques ;
Journal of Microbiology and Biotechnology, volume 20, issue 4, 2010, Pages 779~781
DOI : 10.4014/jmb.0906.06049
After preliminary tests indicated an increased number of heterotrophic bacteria, we investigated possible sources of contamination in a neonatal intensive care unit (NICU) water distribution system. Scanning electron microscopic examination of flexible metallic hoses associated with the system revealed the presence of a biofilm; partial 16S rDNA sequencing revealed that the biofilm contained Blastomonas natatoria. Purgation of the water system three times a day, reinforced faucet cleaning, decreasing the cold water temperature to
, and six repeated chlorinations at concentrations as high as 2 mg/l were not sufficient to eradicate the bacterial contamination. Replacing all of the rubber-interior flexible metallic hoses with teflon-lined hoses, followed by heating the water to
, successfully controlled the bacteria.
Calcite-Forming Bacteria for Compressive Strength Improvement in Mortar
Park, Sung-Jin ; Park, Yu-Mi ; Chun, Woo-Young ; Kim, Wha-Jung ; Ghim, Sa-Youl ;
Journal of Microbiology and Biotechnology, volume 20, issue 4, 2010, Pages 782~788
DOI : 10.4014/jmb.0911.11015
Microbiological calcium carbonate precipitation (MCP) has been investigated for its ability to improve the compressive strength of mortar. However, very few studies have been conducted on the use of calcite-forming bacteria (CFB) to improve compressive strength. In this study, we discovered new bacterial genera that are capable of improving the compressive strength of mortar. We isolated 4 CFB from 7 environmental concrete structures. Using sequence analysis of the 16S rRNA genes, the CFB could be partially identified as Sporosarcina soli KNUC401, Bacillus massiliensis KNUC402, Arthrobacter crystallopoietes KNUC403, and Lysinibacillus fusiformis KNUC404. Crystal aggregates were apparent in the bacterial colonies grown on an agar medium. Stereomicroscopy, scanning electron microscopy, and X-ray diffraction analyses illustrated both the crystal growth and the crystalline structure of the
crystals. We used the isolates to improve the compressive strength of cement-sand mortar cubes and found that KNUC403 offered the best improvement in compressive strength.
Differential Gene Expression in the Pathogenic Strains of Actinobacillus pleuropneumoniae Serotypes 1 and 3
Xie, Fang ; Zhang, Mingjun ; Li, Shuqing ; Du, Chongtao ; Sun, Changjiang ; Han, Wenyu ; Zhou, Liang ; Lei, Liancheng ;
Journal of Microbiology and Biotechnology, volume 20, issue 4, 2010, Pages 789~797
DOI : 10.4014/jmb.0910.10040
The limited information on differential gene expression in the different serotypes of Actinobacillus pleuropneumoniae has significantly hampered the research on the pathogenic mechanisms of this organism and the development of multivalent vaccines against A. pleuropneumoniae infection. To compare the gene expressions in the A. pleuropneumoniae strains CVCC259 (serotype 1) and CVCC261 (serotype 3), we screened the differentially expressed genes in the two strains by performing representational difference analysis (RDA). Northern blot analyses were used to confirm the results of RDA. We identified 22 differentially expressed genes in the CVCC259 strain and 20 differentially expressed genes in the CVCC261 strain, and these genes were classified into 11 groups: (1) genes encoding APX toxins; (2) genes encoding transferrin-binding protein; (3) genes involved in lipopolysaccharide (LPS) biosynthesis; (4) genes encoding autotransporter adhesin; (5) genes involved in metabolism; (6) genes involved in the ATP-binding cassette (ABC) transporter system; (7) genes encoding molecular chaperones; (8) genes involved in bacterial transcription and nucleic acid metabolism; (9) a gene encoding protease; (10) genes encoding lipoprotein/membrane protein; and (11) genes encoding various hypothetical proteins. This is the first report on the systematic application of RDA for the analysis of differential gene expression in A. pleuropneumoniae serotypes 1 and 3. The determination of these differentially expressed genes will serve as an indicator for future research on the pathogenic mechanisms of A. pleuropneumoniae and the development of a multivalent vaccine against A. pleuropneumoniae infection.
High Prevalence of Fluoroquinolone- and Methicillin-Resistant Staphylococcus pseudintermedius Isolates from Canine Pyoderma and Otitis Externa in Veterinary Teaching Hospital
Yoo, Jong-Hyun ; Yoon, Jang-W. ; Lee, So-Young ; Park, Hee-Myung ;
Journal of Microbiology and Biotechnology, volume 20, issue 4, 2010, Pages 798~802
DOI : 10.4014/jmb.0910.10044
Recently, a total of 74 Staphylococcus pseudintermedius isolates were collected from clinical cases of canine pyoderma and otitis externa in Korea. In this study, we examined in vitro fluoroquinolone resistance among those isolates using a standard disc diffusion technique. The results demonstrated that, except for one isolate, approximately 18.9% to 27.0% of the isolates possessed bacterial resistance to both veterinary- and human-licensed fluoroquinolones including moxifloxacin (18.9% resistance), levofloxacin (20.3% resistance), ofloxacin (24.3% resistance), ciprofloxacin (25.7% resistance), and enrofloxacin (27.0% resistance). Most surprisingly, 14 out of 74 (18.9%) isolates were resistant to all the five fluoroquinolones evaluated. Moreover, a PCR detection of the methicillin resistance gene (mecA) among the 74 isolates revealed that 13 out of 25 (52.0%) mecApositive isolates, but only 7 out of 49 (14.3%) mecA-negative isolates, were resistant to one or more fluoroquinones. Taken together, our results imply that bacterial resistance to both veterinary- and human-use fluoroquinolones becomes prevalent among the S. pseudintermedius isolates from canine pyoderma and otitis externa in Korea, as well as that the high prevalence of the mecA-positive S. pseudintermedius isolates carrying multiple fluoroquinolones resistance could be a potential public health problem.
Effects of Ultra High Molecular Weight Poly-
-glutamic Acid from Bacillus subtilis (chungkookjang) on Corneal Wound Healing
Bae, Sun-Ryang ; Park, Chung ; Choi, Jae-Chul ; Poo, Ha-Ryoung ; Kim, Chul-Joong ; Sung, Moon-Hee ;
Journal of Microbiology and Biotechnology, volume 20, issue 4, 2010, Pages 803~808
DOI : 10.4014/jmb.0911.11021
-glutamic acid (
-PGA) is a natural edible polypeptide in which glutamate is polymerized via
-amide linkages. First, we assessed the eye irritancy potential of
-PGA in rabbits. Additionally, we studied the effects of
-PGA on corneal wound healing, due to the anti-inflammatory properties and water retaining abilities of
-PGA. In this study, the effects of
-PGA on corneal wound healing after an alkali burn were evaluated. Thirty eyes wounded by alkali burning in 30 white rabbits were divided into three groups: group A was treated with 0.1% 5,000 kDa
-PGA for 2 days; group B was treated with 0.1% hyaluronic acid; and group C was not treated, as a control. The area of corneal epithelial defect was examined at 12, 24, 30, 36, 42, and 48 h after corneal alkali wounding to determine initial wound healing. We found that
-PGA promoted corneal wound healing, compared with controls, and showed similar effects to hyaluronic acid. These results indicate that
-PGA stimulates corneal wound healing by an anti-inflammatory effect and enhancing cell migration and cell proliferation.
-PGA is a promising biomaterial that may be a substitute for hyaluronic acid in corneal wound healing treatment.
Biotransformation of Valdecoxib by Microbial Cultures
Srisailam, K. ; Veeresham, C. ;
Journal of Microbiology and Biotechnology, volume 20, issue 4, 2010, Pages 809~816
DOI : 10.4014/jmb.0910.10027
Microbial biotransformations can be used to predict mammalian drug metabolism. The present investigation deals with microbial biotransformation of valdecoxib using microbial cultures. Thirty-nine bacterial, fungal, and yeast cultures were used to elucidate the biotransformation pathway of valdecoxib. A number of microorganisms metabolized valdecoxib to various levels to yield nine metabolites, which were identified by HPLC-DAD and LC-MS-MS analyses. HPLC analysis of biotransformed products indicated that a majority of the metabolites are more polar than the substrate valdecoxib. Basing on LC-MS-MS analysis, the major metabolite was identified as a hydroxymethyl metabolite of valdecoxib, whereas the remaining metabolites were produced by carboxylation, demethylation, ring hydroxylation, N-acetylation, or a combination of these reactions. The hydroxymethyl and carboxylic acid metabolites were known to be produced in metabolism by mammals. From the results, it can be concluded that microbial cultures, particularly fungi, can be used to predict mammalian drug metabolism.
Proteomic Analysis of Pancreata from Mini-Pigs Treated with Streptozotocin as Type I Diabetes Models
Lee, Phil-Young ; Park, Sung-Goo ; Kim, Eun-Young ; Lee, Myung-Sup ; Chung, Sang-J. ; Lee, Sang-Chul ; Yu, Dae-Yeul ; Bae, Kwang-Hee ;
Journal of Microbiology and Biotechnology, volume 20, issue 4, 2010, Pages 817~820
DOI : 10.4014/jmb.0909.09027
Type 1 diabetes mellitus (T1DM) is an autoimmune disease characterized by extreme insulin deficiency due to an overall reduction in the mass of functional pancreatic
-cells. Several animal models have been used to study T1DM. Amongst these, the mini-pig seems to be the most ideal model for diabetes research, owing to similarities with humans in anatomy and physiology. The purpose of this study was to analyze differentially expressed pancreatic proteins in a streptozotocin (STZ)-induced mini-pig T1DM model. Pancreas proteins from mini-pigs treated with STZ were separated by two-dimensional gel electrophoresis, and 11 protein spots were found to be altered significantly when compared with control mini-pigs. The data in this study utilizing proteomic analysis provide a valuable resource for the further understanding of the T1DM pathomechanism.
Selective Gene Transfer to Hepatocellular Carcinoma Using Homing Peptide-Grafted Cationic Liposomes
Tu, Ying ; Kim, Ji-Seon ;
Journal of Microbiology and Biotechnology, volume 20, issue 4, 2010, Pages 821~827
DOI : 10.4014/jmb.0910.10008
Gene delivery that provides targeted delivery of therapeutic genes to the cells of a lesion enhances therapeutic efficacy and reduces toxic side effects. This process is especially important in cancer therapy when it is advantageous to avoid unwanted damage to healthy normal cells. Incorporating cancer-specific ligands that recognize receptors overexpressed on cancer cells can increase selective binding and uptake and, as a result, increase targeted transgene expression. In this study, we investigated whether a peptide capable of homing to hepatocellular carcinoma (HCC) could facilitate targeted gene delivery by cationic liposomes. This homing peptide (HBP) exhibited selective binding to a human hepatocarcinoma cell line, HepG2, at a concentration ranging from 5 to 5,000 nM. When conjugated to a cationic liposome, HBP substantially increased cellular internalization of plasmid DNA to increase the transgene expression in HepG2 cells. In addition, there was no significant enhancement in gene transfer detected for other human cell lines tested, including THLE-3, AD293, and MCF-7 cells. Therefore, we demonstrate that HBP provides targeted gene delivery to HCC by cationic liposomes.
Isolation and Characterization of Ethanol-Producing Schizosaccharomyces pombe CHFY0201
Choi, Gi-Wook ; Um, Hyun-Ju ; Kim, Mi-Na ; Kim, Yule ; Kang, Hyun-Woo ; Chung, Bong-Woo ; Kim, Yang-Hoon ;
Journal of Microbiology and Biotechnology, volume 20, issue 4, 2010, Pages 828~834
DOI : 10.4014/jmb.0910.10003
An ethanol-producing yeast strain, CHFY0201, was isolated from soil in South Korea using an enrichment technique in a yeast peptone dextrose medium supplemented with 5% (w/v) ethanol at
. The phenotypic and physiological characteristics, as well as molecular phylogenetic analysis based on the D1/D2 domains of the large subunit (26S) rDNA gene and the internally transcribed spacer (ITS) 1+2 regions, suggested that the CHFY0201 was a novel strain of Schizosaccharomyces pombe. During shaking flask cultivation, the highest ethanol productivity and theoretical yield of S. pombe CHFY0201 in YPD media containing 9.5% total sugars were
, respectively. Simultaneous saccharification and fermentation for ethanol production was carried out using liquefied cassava (Manihot esculenta) powder in a 5-l lab-scale jar fermenter at
for 66 h with an agitation speed of 120 rpm. Under these conditions, S. pombe CHFY0201 yielded a final ethanol concentration of
g/l and a theoretical yield of
at a maximum ethanol productivity of
g/l/h. These results suggest that S. pombe CHFY0201 is a potential producer for industrial bioethanol production.
Optimization of Hydroxyl Radical Scavenging Activity of Exopolysaccharides from Inonotus obliquus in Submerged Fermentation Using Response Surface Methodology
Chen, Hui ; Xu, Xiangqun ; Zhu, Yang ;
Journal of Microbiology and Biotechnology, volume 20, issue 4, 2010, Pages 835~843
DOI : 10.4014/jmb.0909.09017
The objectives of this study were to investigate the effect of fermentation medium on the hydroxyl radical scavenging activity of exopolysaccharides from Inonotus obliquus by response surface methodology (RSM). A two-level fractional factorial design was used to evaluate the effect of different components of the medium. Corn flour, peptone, and
were important factors significantly affecting hydroxyl radical scavenging activity. These selected variables were subsequently optimized using path of steepest ascent (descent), a central composite design, and response surface analysis. The optimal medium composition was (% w/v): corn flour 5.30, peptone 0.32,
0.01. Under the optimal condition, the hydroxyl radical scavenging rate (49.4%) was much higher than that using either basal fermentation medium (10.2%) and single variable optimization of fermentation medium (35.5%). The main monosaccharides components of the RSM optimized polysaccharides are rhamnose, arabinose, xylose, mannose, glucose, and galactose with molar proportion at 1.45%, 3.63%, 2.17%, 15.94%, 50.00%, and 26.81%.
Effects of Dissolved Oxygen on Fungal Morphology and Process Rheology During Fed-Batch Processing of Ganoderma lucidum
Fazenda, Mariana L. ; Harvey, Linda M. ; McNeil, Brian ;
Journal of Microbiology and Biotechnology, volume 20, issue 4, 2010, Pages 844~851
DOI : 10.4014/jmb.0911.11020
Controlling the dissolved oxygen (DO) in the fed-batch culture of the medicinal mushroom Ganoderma lucidum led to a 2-fold increase of the maximum biomass productivity compared with uncontrolled DO conditions. By contrast, extracellular polysaccharide (EPS) production was two times higher under oxygen limitation (uncontrolled DO) than under increased oxygen availability (controlled DO). Morphologically, dispersed mycelium was predominant under controlled DO conditions, with highly branched hyphae, consistent with the enhanced culture growth noted under these conditions, whereas in the uncontrolled DO process mycelial clumps were the most common morphology throughout the culture. However, in both cultures, clamp connections were found. This is an exciting new finding, which widens the applicability of this basidiomycete in submerged fermentation. In rheological terms, broths demonstrated shear-thinning behavior with a yield stress under both DO conditions. The flow curves were best described by the Herschel-Bulkley model: flow index down to 0.6 and consistency coefficient up to 0.2 and 0.6 Pa
in uncontrolled and controlled cultures DO, respectively. The pseudoplastic behavior was entirely due to the fungal biomass, and not to the presence of EPS (rheological analysis of the filtered broth showed Newtonian behavior). It is clear from this study that dissolved oxygen tension is a critical process parameter that distinctly influences G. lucidum morphology and rheology, affecting the overall performance of the process. This study contributes to an improved understanding of the process physiology of submerged fermentation of G. lucidum.