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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 18, Issue 12 - Dec 2008
Volume 18, Issue 11 - Nov 2008
Volume 18, Issue 10 - Oct 2008
Volume 18, Issue 9 - Sep 2008
Volume 18, Issue 8 - Aug 2008
Volume 18, Issue 7 - Jul 2008
Volume 18, Issue 6 - Jun 2008
Volume 18, Issue 5 - May 2008
Volume 18, Issue 4 - Apr 2008
Volume 18, Issue 3 - Mar 2008
Volume 18, Issue 2 - Feb 2008
Volume 18, Issue 1 - Jan 2008
Selecting the target year
Nocardioides tritolerans sp. nov., Isolated from Soil in Bigeum Island, Korea
Dastager, Syed G. ; Lee, Jae-Chan ; Ju, Yoon-Jung ; Park, Dong-Jin ; Kim, Chang-Jin ;
Journal of Microbiology and Biotechnology, volume 18, issue 7, 2008, Pages 1203~1206
A Gram-positive strain designated as MSL-
isolated from a soil sample collected from Bigeum Island, Korea, was subjected to polyphasic taxonomy. The isolate was strictly aerobic. Cells were short rods and motile. Optimum growth temperature and pH was 28
and 7.0, respectively. It was characterized chemotaxonomically as having a cell-wall peptidoglycan type based on LL-2,6-diaminopimelic acid and MK-
as the predominant menaquinone. The major fatty acids were iso-
omega9c. The G+C content was 67.6 mol%. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain MSL-
is affiliated to the genus Nocardioides and formed a distinct lineage within the genus. MSL-
showed highest sequence similarity to Nocardioides aestuarii JCM
, having a similarity of 96.5%. Based on the 16S rRNA gene sequence divergence and phenotypic characteristics, it is proposed that strain MSL-
should be classified as representing a novel member of the genus Nocardioides, for which we propose the name Nocardioides tritolerans sp. novo The type strain is strain MSL-
Occurrence and Molecular Differentiation of Environmental Mycobacteria in Surface Waters
Lee, Eun-Sook ; Lee, Mok-Young ; Han, Sun-Hee ; Ka, Jong-Ok ;
Journal of Microbiology and Biotechnology, volume 18, issue 7, 2008, Pages 1207~1215
To investigate the occurrence and species diversity of mycobacteria in waters, surface water samples were collected monthly from the Han River and tap water samples at the terminal sites of the distribution system. Mycobacteria in each water sample were isolated by decontamination using cetylpyridinium chloride (CPC) and cultivation on Middlebrook 7H10 agar, and then identified by polymerase chain reaction-restriction fragment length polymorphism analysis (PRA) and sequencing of the 65-kDa heat-shock protein gene (hsp65 gene). Mycobacteria were detected in 59% of the surface water samples and 26% of the tap water samples. Over half of the 158 isolates could not be identified by hsp65 PRA and gene sequencing, and several identification discrepancies were observed between the two methods. The most frequently isolated species was Mycobacterium gordonae in surface water and M. lentiflavum in tap water. M. avium complex (MAC), the most important pathogen among environmental mycobacteria, was detected in the surface water samples but not found in the tap water samples. The result demonstrated that water is an important environmental source of mycobacteria and the combined application of hsp65 PRA and sequencing was more reliable than hsp65 PRA alone to accurately identify mycobacteria present in water.
Cloning and Functional Characterization of the Germacradienol Synthase (spterp13) from Streptomyces peucetius ATCC 27952
Ghimire, Gopal Prasad ; Oh, Tae-Jin ; Lee, Hei-Chan ; Kim, Byung-Gee ; Sohng, Jae-Kyung ;
Journal of Microbiology and Biotechnology, volume 18, issue 7, 2008, Pages 1216~1220
Sequence analysis of the metabolically rich genome of Streptomyces peucetius ATCC 27952 revealed a 2,199 bp sesquiterpene alcohol (germacradienol) synthase-encoding gene from the germacradienol synthase/terpene cyclase gene cluster. The gene was named spterp13, and its putative function is as a germacradienol synthase/terpene cyclase. The amino acid sequence of Spterp13 shows 66% identity with SAV2163 (GeoA) from S. avermitilis MA4680 and 65% identity with SCO6073 from S. coelicolor A3(2), which produces germacradienol/geosmin. The full-length recombinant protein was heterologously expressed as a his-tagged fusion protein in Escherichia coli, purified, and shown to catalyze the
-dependent conversion of farnesyl diphosphate to the germacradienol, which was verified by gas chromatography/mass spectrometry.
Cloning, Expression, and Characterization of a New Phytase from the Phytopathogenic Bacterium Pectobacterium wasabiae DSMZ 18074
Shao, Na ; Huang, Huoqing ; Meng, Kun ; Luo, Huiying ; Wang, Yaru ; Yang, Peilong ; Yao, Bin ;
Journal of Microbiology and Biotechnology, volume 18, issue 7, 2008, Pages 1221~1226
The soft rot bacterium Pectobacterium wasabiae is an economically important pathogen of many crops. A new phytase gene, appA, was cloned from P. wasabiae by degenerate PCR and TAIL-PCR. The open reading frame of appA consisted of 1,302 bp encoding 433 amino acid residues, including 27 residues of a putative signal peptide. The mature protein had a molecular mass of 45 kDa and a theoretical pI of 5.5. The amino acid sequence contained the conserved active site residues RHGXRXP and HDTN of typical histidine acid phosphatases, and showed the highest identity of 48.5% to PhyM from Pseudomonas syringae. The gene fragment encoding the mature phytase was expressed in Escherichia coli BL21 (DE3), and the purified recombinant phytase had a specific activity of 1,072
47 U/mg for phytate substrate. The optimum pH and temperature for the purified phytase were pH 5.0 and 50
, respectively. The
value was 0.17 mM, with a
mol/min/mg. This is the first report of the identification and isolation of phytase from Pectobacterium.
Effect of PEL Exopolysaccharide on the wspF Mutant Phenotypes in Pseudomonas aeruginosa PA14
Chung, In-Young ; Choi, Kelly B. ; Heo, Yun-Jeong ; Cho, You-Hee ;
Journal of Microbiology and Biotechnology, volume 18, issue 7, 2008, Pages 1227~1234
Pseudomonas aeruginosa is an opportunistic human pathogen that produces and secretes exopolysaccharides (EPS), in which cells are embedded to form a highly organized community structure called biofilm. Here, we characterized the role of cyclic diguanylate (c-di-GMP) and EPS (PEL) overproduction in the wspF mutant phenotypes of P. aeruginosa PA14 (wrinkly appearance, hyperadherence, impaired motilities, and reduced virulence in acute infections). We confirmed that the elevated c-di-GMP level plays a key role in all the wspF mutant phenotypes listed above, as assessed by ectopic expression of a c-di-GMP-degrading phophodiesterase (PvrR) in the wspF mutant. In contrast, PEL EPS, which is overproduced in the wspF mutant, was necessary for wrinkly appearance and hyperadherence, but not for the impaired flagellar motilities and the attenuated virulence of the wspF mutant. These results suggest that c-di-GMP affects flagellar motility and virulence, independently of EPS production and surface adherence of this bacterium.
Functional Identification and Expression of Indole-3-Pyruvate Decarboxylase from Paenibacillus polymyxa E681
Phi, Quyet-Tien ; Park, Yu-Mi ; Ryu, Choong-Min ; Park, Seung-Hwan ; Ghim, Sa-Youl ;
Journal of Microbiology and Biotechnology, volume 18, issue 7, 2008, Pages 1235~1244
Indole-3-acetic acid (IAA) is produced commonly by plants and many bacteria, however, little is known about the genetic basis involving the key enzymes of IAA biosynthetic pathways from Bacillus spp. IAA intermediates from the Gram-positive spore-forming bacterium Paenibacillus polymyxa E681 were investigated, which showed the existence of only an indole-3-pyruvic acid (IPA) pathway for IAA biosynthesis from the bacterium. Four open reading frames (ORFs) encoding indole-3-pyruvate decarboxylase-like proteins and putative indole-3-pyruvate decarboxylase (IPDC), a key enzyme in the IPA synthetic pathway, were found on the genome sequence database of P. polymyxa and cloned in Escherichia coli DH5
. One of the ORFs, PP2_01257, was assigned as probable indole-3-pyruvate decarboxylase. The ORF consisted of 1,743 nucleotides encoding 581 amino acids with a deduced molecular mass of 63,380 Da. Alignment studies of the deduced amino acid sequence of the ORF with known IPDC sequences revealed conservation of several amino acids in PP2_01257, essential for substrate and cofactor binding. Recombinant protein, gene product of the ORF PP2_01257 from P. polymyxa E681, was expressed in E. coli BL21 (DE3) as a glutathione S-transferase (GST)-fusion protein and purified to homogeneity using affinity chromatography. The molecular mass of the purified enzyme showed about 63 kDa, corresponding closely to the expected molecular mass of IPDC. The indole-3-pyruvate decarboxylase activity of the recombinant protein, detected by HPLC, using IPA substrate in the enzyme reaction confirmed the identity and functionality of the enzyme IPDC from the E681 strain.
Oxalate Decarboxylase from Agrobacterium tumefaciens C58 is Translocated by a Twin Arginine Translocation System
Shen, Yu-Hu ; Liu, Rui-Juan ; Wang, Hai-Qing ;
Journal of Microbiology and Biotechnology, volume 18, issue 7, 2008, Pages 1245~1251
Oxalate decarboxylases (OXDCs) (E.C. 220.127.116.11) are enzymes catalyzing the conversion of oxalate to formate and
. The OXDCs found in fungi and bacteria belong to a functionally diverse protein superfamily known as the cupins. Fungi-originated OXDCs are secretory enzymes. However, most bacterial OXDCs are localized in the cytosol, and may be involved in energy metabolism. In Agrobacterium tumefaciens C58, a locus for a putative oxalate decarboxylase is present. In the study reported here, an enzyme was overexpressed in Escherichia coli and showed oxalate decarboxylase activity. Computational analysis revealed the A. tumefaciens C58 OXDC contains a signal peptide mediating translocation of the enzyme into the periplasm that was supported by expression of signal-peptideless and full-length versions of the enzyme in A. tumefaciens C58. Further site-directed mutagenesis experiment demonstrated that the A. tumefaciens C58 OXDC is most likely translocated by a twin-arginine translocation (TAT) system.
Cell Recycled Culture of Succinic Acid-Producing Anaerobiospirillum succiniciproducens Using an Internal Membrane Filtration System
Lee, Pyung-Cheon ; Lee, Sang-Yup ; Chang, Ho-Nam ;
Journal of Microbiology and Biotechnology, volume 18, issue 7, 2008, Pages 1252~1256
Cell recycled culture of succinic acid-producing Anaerobiospirillum succiniciproducens was anaerobically carried out using an internal membrane filter module in order to examine the physiological response of A. succiniciproducens to a high-cell-density environment. The optimal growth of A. succiniciproducens and its enhanced succinic acid productivity were observed under
-rich conditions, established by adding
, in the cell recycled system. A. succiniciproducens grew up to 6.50 g-DCW/l, the highest cell concentration obtained so far, in cell recycled cultures. The cells did not change their morphology, which is known to be easily changed in unfavorable or stress environments. The maximum productivity of succinic acid was about 3.3 g/l/h, which is 3.3 times higher than those obtained in batch cultures. These results can serve as a guide for designing highly efficient cell recycled systems for succinic acid at a commercial level.
High-Solid Enzymatic Hydrolysis and Fermentation of Solka Floc into Ethanol
Um, Byung-Hwan ; Hanley, Thomas R. ;
Journal of Microbiology and Biotechnology, volume 18, issue 7, 2008, Pages 1257~1265
To lower the cost of ethanol distillation of fermentation broths, a high initial glucose concentration is desired. However, an increase in the substrate concentration typically reduces the ethanol yield because of insufficient mass and heat transfer. In addition, different operating temperatures are required to optimize the enzymatic hydrolysis (50
) and fermentation (30
). Thus, to overcome these incompatible temperatures, saccharification followed by fermentation (SFF) was employed with relatively high solid concentrations (10% to 20%) using a portion loading method. In this study, glucose and ethanol were produced from Solka Floc, which was first digested by enzymes at 50
for 48 h, followed by fermentation. In this process, commercial enzymes were used in combination with a recombinant strain of Zymomonas mobilis (39679:pZB4L). The effects of the substrate concentration (10% to 20%, w/v) and reactor configuration were also investigated. In the first step, the enzyme reaction was achieved using 20 FPU/g cellulose at 50
for 96 h. The fermentation was then performed at 30
for 96 h. The enzymatic digestibility was 50.7%, 38.4%, and 29.4% after 96 h with a baffled Rushton impeller and initial solid concentration of 10%, 15%, and 20% (w/v), respectively, which was significantly higher than that obtained with a baffled marine impeller. The highest ethanol yield of 83.6%, 73.4%, and 21.8%, based on the theoretical amount of glucose, was obtained with a substrate concentration of 10%, 15%, and 20%, respectively, which also corresponded to 80.5%, 68.6%, and 19.1%, based on the theoretical amount of the cell biomass and soluble glucose present after 48 h of SFF.
Fermentation Characteristics of Exopolysaccharide-Producing Lactic Acid Bacteria from Sourdough and Assessment of the Isolates for Industrial Potential
Jung, Seung-Won ; Kim, Wang-June ; Lee, Kwang-Geun ; Kim, Cheol-Woo ; Noh, Wan-Seob ;
Journal of Microbiology and Biotechnology, volume 18, issue 7, 2008, Pages 1266~1273
Lactic acid bacteria (LAB) with antimicrobial activity and high exopolysaccharide (EPS) production ability isolated from sourdough were studied for their fermentation characteristics as potential new starter cultures. The values of pH, titratable acidity, and viable cell counts were
log CFU/ml, respectively. In order to select probiotics with a high survival rate in the gut, isolates were tested to assess resistance against the artificial gastric acid and bile juice. Viable LAB counts were significantly (p<0.05) affected by the acidity. At pH 2.0, the total declines in the initial bacterial counts were 4.52
0.07 log for S. thermophilus St-Body-1, >7.98
0.03 log for E. flavescens DU-10, >7.95
0.05 log for E. faecium DU-12, and 3.15
0.06 log for L. amylovorus DU-21. Among the strains, L. amylovorus DU-21 was the only strain that had bile tolerance under simulated gastrointestinal conditions. In order to improve EPS production by L. amylovorus DU-21, the influence of carbon source was studied. When glucose was used as a carbon source, EPS production dramatically increased to 17.19
0.28 g/l (p<0.05). The maximum cell growth (10.012
>0.012 log CFU/ml) and EPS production (18.71
0.19 g/l) were achieved when 15 g/l of glucose was employed as the carbon source.
Inactivation of Listeria monocytogenes in Brine and Saline by Alternating High-Voltage Pulsed Current
Lee, Mi-Hee ; Han, Dong-Wook ; Woo, Yeon-I. ; Uzawa, Masakazu ; Park, Jong-Chul ;
Journal of Microbiology and Biotechnology, volume 18, issue 7, 2008, Pages 1274~1277
The inactivating efficiency of alternating high-voltage pulsed (AHVP) current was investigated in brine (20 w/v% NaCl) and saline (0.9 w/v% NaCl) inoculated with
cells/ml of Listeria monocytogenes. AHVP current at 12 V with 1 pulse completely inactivated L. monocytogenes in brine within 3 ms, while the bacteria in saline were fully inactivated by 10-pulsed electric treatment at 12 V within the same time. Electron microscopic observation demonstrated substantial structural damage of electrically treated L. monocytogenes in brine. These results suggest that AHVP treatment would be effective for the rapid and complete inactivation of L. monocytogenes in brine or saline solution.
Inhibition of Escherichia coli O157:H7 Attachment by Interactions Between Lactic Acid Bacteria and Intestinal Epithelial Cells
Kim, Young-Hoon ; Kim, Sae-Hun ; Whang, Kwang-Youn ; Kim, Young-Jun ; Oh, Se-Jong ;
Journal of Microbiology and Biotechnology, volume 18, issue 7, 2008, Pages 1278~1285
The intestinal epithelial cell (IEC) layer of the intestinal tract makes direct contact with a number of microbiota communities, including bacteria known to have deleterious health effects. IECs possess innate protective strategies against pathogenic challenge, which primarily involve the formation of a physicochemical barrier. Intestinal tract mucins are principal components of the mucus layer on epithelial surfaces, and perform a protective function against microbial damage. However, little is currently known regarding the interactions between probiotics/pathogens and epithelial cell mucins. The principal objective of this study was to determine the effects of Lactobacillus on the upregulation of MUC2 mucin and the subsequent inhibition of E. coli O157:H7 attachment to epithelial cells. In the current study, the attachment of E. coli O157:H7 to HT-29 intestinal epithelial cells was inhibited significantly by L. acidophilus A4 and its cell extracts. It is also important to note that the expression of MUC2 mucin was increased as the result of the addition of L. acidophilus A4 cell extracts (10.0 mg/ml), which also induced a significant reduction in the degree to which E. coli O157:H7 attached to epithelial cells. In addition, the mRNA levels of IL-8, IL-1
, and TNF-
in HT-29 cells were significantly induced by treatment with L. acidophilus A4 extracts. These results indicate that MUC2 mucin and cytokines are important regulatory factors in the immune systems of the gut, and that selected lactobacilli may be able to induce the upregulation of MUC2 mucin and specific cytokines, thereby inhibiting the attachment of E. coli O157:H7.
Interference of In Vitro and In Vivo Growth of Several Intestinal Bacteria by Lactococcus Strains
Kimoto-Nira, Hiromi ; Ohmomo, Sadahiro ; Nomura, Masaru ; Kobayashi, Miho ; Mizumahi, Koko ; Okamoto, Takashi ;
Journal of Microbiology and Biotechnology, volume 18, issue 7, 2008, Pages 1286~1289
The ability of Lactococcus strains to inhibit the growth of intestinal bacteria was examined. In in vitro cocultures, we observed that among eighteen Lactococcus strains tested, the ability to inhibit growth of Escherichia coli varied, with the L. lactis N7 showing the greatest growth inhibition. Strain N7 (
CFU/day for 7 days) was orally administered to mice, and the viable count of strain N7 in feces appeared at a level of
CFU/g. After administration, the proportion of Bacteroidaceae to total intestinal bacteria decreased. Lactococci may act as probiotic bacteria by inhibiting the growth of harmful bacteria.
Fine-Scale Population Structure of Accumulibacter phosphatis in Enhanced Biological Phosphorus Removal Sludge
Wang, Qian ; Shao, Yongqi ; Huong, Vu Thi Thu ; Park, Woo-Jun ; Park, Jong-Moon ; Jeon, Che-Ok ;
Journal of Microbiology and Biotechnology, volume 18, issue 7, 2008, Pages 1290~1297
To investigate the diversities of Accumulibacter phosphatis and its polyhydroxyalkanoate (PHA) synthase gene (phaC) in enhanced biological phosphorus removal (EBPR) sludge, an acetate-fed sequencing batch reactor was operated. Analysis of microbial communities using fluorescence in situ hybridization and 16S rRNA gene clone libraries showed that the population of Accumulibacter phosphatis in the EBPR sludge comprised more than 50% of total bacteria, and was clearly divided into two subgroups with about 97.5% sequence identity of the 16S rRNA genes. PAO phaC primers targeting the phaC genes of Accumulibacter phosphatis were designed and applied to retrieve fragments of putative phaC homologs of Accumulibacter phosphatis from EBPR sludge. PAO phaC primers targeting
groups produced PCR amplicons successfully; the resulting sequences of the phaC gene homologs were diverse, and were distantly related to metagenomic phaC sequences of Accumulibacter phosphatis with 75-98% DNA sequence identities. Degenerate NPAO (non-PAO) phaC primers targeting phaC genes of non-Accumulibacter phosphatis bacteria were also designed and applied to the EBPR sludge. Twenty-four phaC homologs retrieved from NPAO phaC primers were different from the phaC gene homologs derived from Accumulibacter phosphatis, which suggests that the PAO phaC primers were specific for the amplification of phaC gene homologs of Accumulibacter phosphatis, and the putative phaC gene homologs by PAO phaC primers were derived from Accumulibacter phosphatis in the EBPR sludge. Among 24 phaC homologs, a phaC homolog (GINPAO-2), which was dominant in the NPAO phaC clone library, showed the strongest signal in slot hybridization and shared approximately 60% nucleotide identity with the
group of Accumulibacter phosphatis, which suggests that GINPAO-2 might be derived from Accumulibacter phosphatis. In conclusion, analyses of the 16S rRNA and phaC genes showed that Accumulibacter phosphatis might be phylogenetically and metabolically diverse.
Toxicity Evaluation of Complex Metal Mixtures Using Reduced Metal Concentrations: Application to Iron Oxidation by Acidithiobacillus ferrooxidans
Cho, Kyung-Suk ; Ryu, Hee-Wook ; Choi, Hyung-Min ;
Journal of Microbiology and Biotechnology, volume 18, issue 7, 2008, Pages 1298~1307
In this study, we investigated the inhibition effects of single and mixed heavy metal ions (
) on iron oxidation by Acidithiobacillus ferrooxidans. Effects of metals on the iron oxidation activity of A. ferrooxidans are categorized into four types of patterns according to its oxidation behavior. The results indicated that the inhibition effects of the metals on the iron oxidation activity were noncompetitive inhibitions. We proposed a reduced inhibition model, along with the reduced inhibition constant (
), which was derived from the inhibition constant (
) of individual metals and represented the tolerance of a given inhibitor relative to that of a reference inhibitor. This model was used to evaluate the toxicity effect (inhibition effect) of metals on the iron oxidation activity of A. ferrooxidans. The model revealed that the iron oxidation behavior of the metals, regardless of metal systems (single, binary, ternary, or quaternary), is closely matched to that of any reference inhibitor at the same reduced inhibition concentration,
, which defines the ratio of the inhibitor concentration to the reduced inhibition constant. The model demonstrated that single metal systems and mixed metal systems with the same reduced inhibitor concentrations have similar toxic effects on microbial activity.
CBT-SL5, a Bacteriocin from Enterococcus faecalis, Suppresses the Expression of Interleukin-8 Induced by Propionibacterium acnes in Cultured Human Keratinocytes
Lee, Ye-Jin ; Choi, Hye-Jeong ; Kang, Tae-Wook ; Kim, Hyung-Ok ; Chun, Myung-Jun ; Park, Young-Min ;
Journal of Microbiology and Biotechnology, volume 18, issue 7, 2008, Pages 1308~1316
Propionibacterium acnes is known to playa pivotal role in the pathogenesis of acne vulgaris. CBT-SL5 is one of the antimicrobial peptides from Enterococcus faecalis SL5, and it has shown antimicrobial activity against P. acnes. The aim of this study was to investigate the anti-inflammatory effect of CBT-SL5 on the inflammation induced by P. acnes in cultured human keratinocyes. Cultured human keratinocytes derived from neonatal foreskin were treated with heat-killed P. acnes to induce inflammation, and then various concentrations of CBT-SL5 were added to the P. acnes-treated keratinocytes. The mRNA expression and protein secretion of interleukin (IL)-8, an inflammation marker, was analyzed by real-time reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. We also analyzed the nuclear factor-kappa B (NF-
) p65 translocation by performing immunofluorescent staining. P. acnes treatment up regulated the IL-8 mRNA expression in the keratinocytes, and this was brought about through both toll-like receptor (TLR)2 and TLR4. At the concentrations of 10, 50, and 100 ng/ml, CBT-SL5 significantly down regulated the P. acnes-induced IL-8 mRNA expression and protein production (p<0.05). At 6 hand 12 h of the treatment, CBT-SL5 significantly suppressed the P. acnes-induced IL-8 mRNA expression. Secretion of IL-8 protein was significantly reduced at 24 h. The functional inhibitory activity of CBT-SL5 was shown by CBT-SL5 suppressing the P. acnes-induced NF-
translocation from the cytoplasm to the nucleus. These results demonstrated that CBT-SL5 suppressed the P. acnes-induced IL-8 expression in keratinocytes. Therefore, CBT-SL5 may be a novel anti-inflammatory treatment for acne.
Improvement of Virus Safety of an Antihemophilc Factor IX by Virus Filtration Process
Kim, In-Seop ; Choi, Yong-Woon ; Kang, Yong ; Sung, Hark-Mo ; Sohn, Ki-Whan ; Kim, Yong-Sung ;
Journal of Microbiology and Biotechnology, volume 18, issue 7, 2008, Pages 1317~1325
Viral safety is an important prerequisite for clinical preparations of plasma-derived pharmaceuticals. One potential way to increase the safety of therapeutic biological products is the use of a virus-retentive filter. In order to increase the viral safety of human antihemophilic factor IX, particularly in regard to non-enveloped viruses, a virus removal process using a polyvinylidene fluoride membrane filter (Viresolve NFP) has been optimized. The most critical factor affecting the filtration efficiency was operating pH and the optimum pH was 6 or 7. Flow rate increased with increasing operating pressure and temperature. Recovery yield in the optimized production-scale process was 96%. No substantial changes were observed in the physical and biochemical characteristics of the filtered factor IX in comparison with those before filtration. A 47-mm disk membrane filter was used to simulate the process performance of the production-scale cartridges and to test if it could remove several experimental model viruses for human pathogenic viruses, including human hepatitis A virus (HAV), porcine parvovirus (PPV), murine encephalomyocarditis virus (EMCV), human immunodeficiency virus type 1 (HIV), bovine viral diarrhea virus (BVDV), and bovine herpes virus (BHV). Non-enveloped viruses (HAV, PPV, and EMCV) as well as enveloped viruses (HIV, BVDV, and BHV) were completely removed during filtration. The log reduction factors achieved were
6.12 for HAV,
4.28 for PPV,
5.33 for EMCV,
5.51 for HIV,
5.17 for BVDV, and
5.75 for BHV. These results indicate that the virus filtration process successfully improved the viral safety of factor IX.
Multiple Alternating Immunizations with DNA Vaccine and Replication-incompetent Adenovirus Expressing gB of Pseudorabies Virus Protect Animals Against Lethal Virus Challenge
Kim, Seon-Ju ; Kim, Hye-Kyung ; Han, Young-Woo ; Aleyas, Abi G. ; George, Junu A. ; Yoon, Hyun-A ; Yoo, Dong-Jin ; Kim, Koan-Hoi ; Eo, Seong-Kug ;
Journal of Microbiology and Biotechnology, volume 18, issue 7, 2008, Pages 1326~1334
The prime-boost vaccination with DNA vaccine and recombinant viral vector has emerged as an effective prophylactic strategy to control infectious diseases. Here, we compared the protective immunities induced by multiple alternating immunizations with DNA vaccine (pCIgB) and replication-incompetent adenovirus (Ad-gB) expressing glycoprotein gB of pseudorabies virus (PrV). The platform of pCIgB-prime and Ad-gB-boost induced the most effective immune responses and provided protection against virulent PrV infection. However, priming with pCIgB prior to vaccinating animals by the DNA vaccine-prime and Ad-boost protocol provided neither effective immune responses nor protection against PrV. Similarly, boosting with Ad-gB following immunization with DNA vaccine-prime and Ad-boost showed no significant responses. Moreover, whereas the administration of Ad-gB for primary immunization induced Th2-type-biased immunity, priming with pCIgB induced Th1-type-biased immunity, as judged by the production of PrV-specific IgG isotypes and cytokine IFN-
. These results indicate that the order and injection frequency of vaccine vehicles used for heterologous prime-boost vaccination affect the magnitude and nature of the immunity. Therefore, our demonstration implies that the prime-boost protocol should be carefully considered and selected to induce the desired immune responses.
Mutanase Induction in Trichoderma harzianum by Cell Wall of Laetiporus sulphureus and its Application for Mutan Removal from Oral Biofilms
Wiater, Adrian ; Szczodrak, Janusz ; Pleszczynska, Malgorzata ;
Journal of Microbiology and Biotechnology, volume 18, issue 7, 2008, Pages 1335~1341
The cell wall material from fruiting bodies of Laetporus sulphureus has been suggested as a new alternative to mutan for the mutanase induction in Trichoderma harzianum. Structural analyses revealed that the cell wall fraction from this polypore fungus contained 56.3% of (1
-glucans. When the strain T. harzianum F-340 was grown on a cell wall preparation from L. sulphureus, the maximal enzyme productivity obtained after 3 days of cultivation was 0.71 U/ml. This yield was about 1.8-fold higher than that achieved on mutan, known so far as the best, but expensive and inaccessible, inducer of mutanase production. Cell-wall-induced mutanase showed a high hydrolytic potential in reaction with a dextranase-pretreated mutan, where maximal degrees of saccharification and solubilization of this biopolymer (80% and 100%, respectively) were reached in 3 h at 45
. The mutanase preparation was also effective in degradation of streptococcal mutan and its removal from oral biofilms, especially in a mixture with dextranase.
Use of Flp-Mediated Cassette Exchange in the Development of a CHO Cell Line Stably Producing Erythropoietin
Kim, Min-Soo ; Lee, Gyun-Min ;
Journal of Microbiology and Biotechnology, volume 18, issue 7, 2008, Pages 1342~1351
The feasibility of the use of Flp-mediated cassette exchange in the development of a CHO cell line, which produces erythropoietin (EPO) stably and largely, was investigated. A stable, high enhanced green fluorescence protein (EGFP)-producing clone was screened by extensive flow cytometric analysis. An EPO expression unit was targeted into the premarked locus of the stable parental clone by Flp-mediated cassette exchange and a correctly targeted clone (FC28T7) was obtained. The EPO production of FC28T7 was proven to be stable in long-term culture. Furthermore, the Flp-mediated cassette exchange did not alter the stable parental clone's characteristics concerning transgene expression level and stability. Taken together, the data obtained here indicated that the establishment of CHO cell lines stably producing a desired protein is achievable using Flp-mediated cassette exchange.