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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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The Korean Journal of Microbiology
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Journal DOI :
The Microbiological Society of Korea
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Volume & Issues
Volume 45, Issue 4 - Dec 2009
Volume 45, Issue 3 - Sep 2009
Volume 45, Issue 2 - Jun 2009
Volume 45, Issue 1 - Mar 2009
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Preparation of Active Human HtrA3 in Eschrichia coli and Comparison of Proteolytic Activity between HtrA1, 2, and 3
Kim, Ji-Hwan ; Kim, Goo-Young ; Nam, Min-Kyung ; Kim, Sang-Soo ; Rhim, Hyang-Shuk ;
The Korean Journal of Microbiology, volume 45, issue 4, 2009, Pages 291~299
To elucidate HtrA3's functional roles in the HtrA3 mediated cellular processes, it is necessary to investigate its biochemical characteristics. In the present study, we constructed the plasmids encoding putative mature HtrA3 proteins (M1-HtrA3 and M2-HtrA3) based on the putative maturation sites of highly homologous HtrA1 and mouse HtrA3. We used the pGEX bacterial expression system to develop a simple and rapid purification for the recombinant HtrA3 protein. Although yields of the mature HtrA3 proteins were slightly low as 10~50
/L, the amounts and purity of M1- and M2-HtrA3 were enough to investigate their proteolytic activities. The putative mature HtrA3 proteins have proteolytic activity which could cleave
-casein as an exogenous substrate. We compared the proteolytic activity between the HtrA family, HtrA1, HtrA2, and HtrA3. The cleavage activity of HtrA3 and HtrA2 were 2 folds higher than that of HtrA1, respectively. Our study provides a method for generating useful reagents to identify natural substrates of HtrA3 in the further studies.
Effects of spNab2 Deletion and Over-Expression on mRNA Export
Yoon, Jin-Ho ;
The Korean Journal of Microbiology, volume 45, issue 4, 2009, Pages 300~305
We constructed the deletion mutants of fission yeast Schizosaccharomyces pombe spNab2 gene that is homologous to poly(A)-binding protein NAB2 in budding yeast Saccharomyces cerevisiae, which plays crucial roles in mRNA 3' end formation and mRNA export from nucleus into the cytoplasm. A null mutant in an
diploid strain was constructed by replacing the spNab2-coding region with an
gene using one-step gene disruption method. Tetrad analysis showed that the spNab2 is not essential for vegetative growth and mRNA export. However, over-expression of spNab2 cause the severe growth defects and intensive accumulation of poly(A) RNA in the nucleus. Also, the spNab2-GFP fusions were localized mainly in the nucleus. These results suggest that spNab2 is also involved in mRNA export out of the nucleus.
Development of a New PCR Method for Detection of Pectobacterium carotovorum
No, Ji-Na ; Yoo, Mi-Sun ; Park, Dong-Suk ; Kim, Jeong-Gu ; Yoon, Byoung-Su ;
The Korean Journal of Microbiology, volume 45, issue 4, 2009, Pages 306~311
A new PCR method was developed to detect Pectobacterium carotovorum which is the causative agent of soft rot in Brassica pekinensis. A specific detection primer set based on Lytic murein transglycolase gene was designed and evaluated. Using ERB3_F (5'-TGC GAC ACC TCC TCA TCA CG-3') and ERB3_R (5'-CTT ATC ACG CTG TAA CCA GC-3') primers, 437 nucleotides long fragment was specifically amplified. The amplified products were observed in 52 out of 55 strains of P. carotovorum or Pectobacterium carotovorum subsp. carotovorum. On the other hand, no amplification was observed in 8 organisms including Chinese cabbage and potato. The optimal PCR condition for the ERB3_F/ERB3_R primer set was
for annealing and 15 mM for
. With serially diluted templates, the specific PCR sensitivitie limit was
copies. Also, this method can be applied not only to DNA but also to field samples. This PCR method may be expected to be useful for specific detection of P. carotovorum.
Structural and Functional Analysis of a Forkhead Gene, fkhF, in a Filamentous Fungus Aspergillus nidulans
Park, Mi-Hye ; Kim, Hyoun-Young ; Kim, Jong-Hwa ; Han, Kap-Hoon ;
The Korean Journal of Microbiology, volume 45, issue 4, 2009, Pages 312~317
Genome analysis of a model filamentous fungus, Aspergillus nidulans, revealed that there are six putative forkhead genes. Among them, fkhF (AN8949.2) showed A. nidulans-specific. fkhF gene is located in chromosome VII and composed of 2,337 bp coding region for 778 amino acid. Since little is known about the involvement of the forkhead proteins in the developmental process of the filamentous fungi, including A. nidulans, we generated a deletion mutant of fkhF gene and analyzed. Deletion of fkhF resulted in less-dense conidiophore formation in a solid culture. However, the sexual developmental process or cleistothecia formation was normal. Furthermore, fkhF deletion mutant produced conidiophores and conidia under the submerged culture, suggesting that the fkhF gene is involved in repression of inappropriated induction and maturation of asexual developmental process but not in sexual development.
Antibacterial Activity against Salmonella enteritidis JK-15 and LPS Changes Caused by Rose Flower Extracts
Song, You-Jin ; Cho, Yun-Seok ; Oh, Kye-Heon ;
The Korean Journal of Microbiology, volume 45, issue 4, 2009, Pages 318~323
The aim of this work was to investigate the antibacterial effect of the food-poisoning bacterium, Salmonella enteritidis JK-15 exposed to rose extracts. Initially, the isolate S. enteritidis JK-15 was enriched and isolated from stale food. BIOLOG and 16S rRNA analyses revealed that strain S. enteritidis JK-15 was 98% similar to the S. enteritidis species cluster; therefore we have designated this strain as S. enteritidis JK-15. Bactericidal effects of S. enteritidis JK-15 exposed to rose extracts ranging from 5 mg/ml to 100 mg/ml were monitored, and complete bactericidal effects were achieved within 6 h at 100 mg/ml and 12 h at 50 mg/ml, respectively. SDSPAGE with silver staining revealed that the amount of lipopolysaccharides increased or decreased in the strain S. enteritidis JK-15 treated to different concentrations and exposing periods of rose extracts in exponentially growing cultures. Scanning electron microscopic analysis, demonstrated the presence of irregular rod shapes with umbilicated surfaces for cells treated with rose extracts.
Optimal Culture Conditions for MK1 Strain Isolated from Soft-Rotten Tissue of Neungee Mushroom (Sarcodon aspratus) and the Physico-Chemical Properties of the Purified Exopolysaccharide of MK1
Ryu, Jeong-Eun ; Lee, Young-Nam ;
The Korean Journal of Microbiology, volume 45, issue 4, 2009, Pages 324~331
MK1 strain, an obligate aerobic heterotrophic bacterium isolated from the rotten tissue of Neungee mushroom (Sarcodon aspratus), produces a copious amount of exopolysaccharide (EPS), which could evoke macrophage activation. Investigations on optimal culture conditions of MK1 and physical properties of MK1 EPS were made. Glucose, galactose, fructose, and sucrose supported well growth of MK1, but potato starch and dextrin did not. However, lactose seemed to be a less favorable carbon source. Optimal growth of MK1 was obtained at pH 7.0,
, and 200 rpm with 2% glucose, and 0.2~0.05%
obtained from an optimal growth condition constituted of carbon (37.1%), nitrogen (2.2%), oxygen (49.3%), and hydrogen (6.4%), but no sulfur. Paper chrogromatogram of the acid-hydrolysate of
suggested that MK1 EPS seemed to be hetropolysaccharide composed of a few number of monosaccharides including amino- and acidic-sugars. Its molecular mass determined by SDS-polyacrylamide gel electrophoresis varied from 14.8 to 47.9 kDa. Physical properties of
obtained from cell grown in glucose medium, such as relative viscosity (
) and crystalline morphology were rather affected by pH of the growth medium. Relative viscosity (
) of exopolysaccaride (0.1 g/ml) harvested from cells grown at medium pH ranging from 6.0 and 7.5 was 1.23 and 1.39, respectively. The freeze-dried exopolysaccharide obtained at low pH (6.0 and 6.5) was fine crystaloid and water-soluble, whereas those obtained at high pH (7.0 and 7.5) was rather gluey and less water-soluble.
Characterization of an Extracellular Xylanase from Bacillus sp. HY-20, a Bacterium in the Gut of Apis mellifera
Lee, Lan-Hee ; Kim, Do-Young ; Han, Mi-Kyoung ; Oh, Hyun-Woo ; Ham, Su-Jin ; Park, Doo-Sang ; Bae, Kyung-Sook ; Sok, Dai-Eun ; Shin, Dong-Ha ; Son, Kwang-Hee ; Park, Ho-Yong ;
The Korean Journal of Microbiology, volume 45, issue 4, 2009, Pages 332~338
A xylan-decomposing bacterium, HY-20, was isolated from the gut of a honeybee, Apis mellifera, and identified as Bacillus sp. The extracellular GH11 xylanase (XylP) gene (687-bp) of strain HY-20 encoded a protein of 228 amino acids with a deduced molecular mass of 25,522 Da and a calculated pI of 9.33. The primary structure of XylP was 97% identical to that of B. pumilus xylanase (GenBank accession no.: AY526092) that has not been characterized yet. The recombinant His-tagged enzyme (rXylP) overexpressed in Escherichia coli BL21 harboring pET-28a(+)/xylP was purified to electrophoretic homogeneity by cation exchange and gel permeation chromatographies. The purified enzyme exhibited the highest catalytic activity toward birchwood xylan at pH 6.5 and
and retained approximately 50% of its original activity when pre-incubated at
for 15 min. The recombinant enzyme was completely inactivated by
(1 mM) and N-bromosuccinimide (5 mM), while its activity was slightly stimulated by approximately 10% in the presence of
(1 mM), and sodium azide (5 mM). rXylP was able to efficiently degrade various polymeric xylose-based substrates but PNP-sugar derivatives and glucose-based polymers were not susceptible to the enzyme.
Isolation, Identification, and Characterization of Weissella Strains with High Ornithine Producing Capacity from Kimchi
Yu, Jin-Ju ; Park, Hyoung-Ju ; Kim, Su-Gon ; Oh, Suk-Heung ;
The Korean Journal of Microbiology, volume 45, issue 4, 2009, Pages 339~345
Two lactic acid bacteria (LAB) with high ornithine-producing capacity were isolated from kimchi. Examination of the biochemical features using an API kit indicated that the strains belonged to the members of Weissella genus. They were gram positive, short rod-type bacteria, and able to grow anaerobically with
production. The isolates grew well on MRS broth at
and pH of 6.0~7.0. The optimum temperature and pH for growth are
and pH 6.5. The isolates fermented arabinose, ribose, xylose, glucose but not cellobiose, galactose, raffinose, or trehalsoe. The 16S rDNA sequences of isolates showed 99.6% and 99.7% homology with the Weissella koreensis S5623 16S rDNA (access no. AY035891). They were accordingly identified and named as Weissella koreensis OK1-4 and Weissella koreensis OK1-6, and could produce ornithine from MRS broth supplemented with 1% of arginine at a productivity of 27.01 and 31.41 mg/L/h, respectively. This is the first report on the production of ornithine by the genus Weissella isolated from kimchi.
Inactivation of Infectious Microorganisms by Disinfection and Sterilization Processes for Human Amniotic Membrane Grafts
Bae, Jung-Eun ; Kim, Chan-Kyung ; Kim, In-Seop ;
The Korean Journal of Microbiology, volume 45, issue 4, 2009, Pages 346~353
Viral, bacterial, and fungal infection can be transmitted from donor to recipient via transplantation of human amniotic membrane. Therefore human amniotic membrane for transplantation should be disinfected and sterilized before use. The purpose of this study was to examine the efficacy of the disinfection process and sterilization processes used at human tissue bank in the inactivation of viruses, bacteria, and fungi. A variety of experimental model viruses, bacteria, and fungus for human pathogens, including the human immunodeficiency virus type 1 (HIV-1), bovine herpes virus (BHV), bovine viral diarrhoea virus (BVDV), hepatitis A virus (HAV), porcine parvovirus (PPV), Escherichia coli, Bacillus subtilis, and Candida albicans were all selected for this study. Enveloped viruses such as HIV-1, BHV, and BVDV were effectively inactivated to undetectable levels by 70% ethanol treatment, gamma irradiation process, and ethylene oxide (EO) gas sterilization process. Also non-enveloped viruses such as HAV and PPV were effectively inactivated to undetectable levels by gamma irradiation and EO gas treatment. However HAV and PPV showed high resistance to 70% ethanol treatment. E. coli and C. albicans were effectively inactivated to undetectable levels by 70% ethanol treatment, gamma irradiation process, and EO gas treatment. Also B. subtilis was effectively inactivated to undetectable levels by gamma irradiation process and EO gas treatment. However it showed high resistance to 70% ethanol treatment.
Clean-up of the Crude Oil Contaminated Marine Sediments Through Biocarrier-Mediated Bioaugmentation
Ekpeghere, Kelvin I. ; Bae, Hwan-Jin ; Kwon, Sung-Hyun ; Kim, Byung-Hyuk ; Park, Duck-Ja ; Kim, Hee-Shik ; Koh, Sung-Cheol ;
The Korean Journal of Microbiology, volume 45, issue 4, 2009, Pages 354~361
This study was carried out to develop an effective biocarrier-mediated bioaugmentation technology which will be useful for remediation of the crude oil-contaminated marine sediments. Enrichment of several microbial communities was made from several oil-polluted seashore sites and the two distinctively functional consortia have been successfully selected. These two consortia were grown together and used to manufacture the microbial agents for bioaugmentation of marine sediments polluted with crude oil. The most dominant species in the mixed culture was identified as Alcanivorax borkumensis based on pure culture and DGGE analysis. Bioaugmentation of oil-polluted marine sediments with the microbial agent MA-2 formulated using the mixed culture and biocarriers (activated carbon and minerals) was more effective, especially in combination with an oxygen producing (releasing) compound (ORC). Ninty percent of TPH was removed in the presence of ORC in 35 days while 74% in the absence of ORC. This indicated that the indigenous consortial degraders could be immobilized on the active carbon as a biocarrier to manufacture microbial agents and then effectively bioaugmented for remediation of the oil-polluted sediments.
Growth Suppression of Microcystis aeruginosa by Pseudomonas aeruginosa AJ1
Kim, Sun-Jung ; Lee, Sang-Seob ;
The Korean Journal of Microbiology, volume 45, issue 4, 2009, Pages 362~367
Among total 176 strains with antialgal effects isolated from So-ok stream in Korea, Pseudomonas aeruginosa AJ1 showed the highest removal efficiency for an algal species Microcystis aeruginosa (clear zone of diameter 50.0 mm on algal lawn after 20 days). The algal growth was suppressed even when the supernatant of AJ1 culture was applied, suggesting that extracellular substances are responsible for its antialgal activity. The removal activity of AJ1 was optimal under the following condition: pH 8,
, and mannitol as a carbon source. The antialgal activity of AJ1 appeared to be dependent of the growth phase of M. aeruginosa, i.e., the highest at the early phase, but not its own phase. As expected, the algicidal effect was improved as the amount of the treated supernatant was increased; the highest removal efficiency (80.3%) was achieved when 40 ml/L of the supernatant was used. Interestingly, however, the removal rate was opposite. The highest removal rate (
chl-a/ml supernatant/day) was achieved when low concentration (10 ml/L) was applied. These results suggest that P. aeruginosa AJ1 is a promising biological agent to control the problematic algal bloom.
Taxonomical Characterization and Antimicrobial Activity of Red Pigment-Producing Marine Bacterium Strain JE-34
Kim, Ju-Sang ; Kim, Man-Chul ; Harikrishnan, Ramasamy ; Han, Yong-Jae ; Heo, Moon-Soo ;
The Korean Journal of Microbiology, volume 45, issue 4, 2009, Pages 368~376
A red pigment-producing bacterial strain was isolated from sediment sample of the East China Sea. The isolate was identified by analysis based on 16S rDNA sequence and morphological, physiological properties, biochemical characteristics and fatty acid composition. Phylogenetic analysis based on 16S rDNA sequence showed that isolate represent a phyletic lineage within the genus Zooshikella, and this strain was most closely related to Zooshikella ganghwensis KCTC
(AY130994) (99.79%). The strain was Gram-negative, aerobic and required NaCl at 0.5~8.0% for growth. The predominant cellular fatty acids were saturated and monounsaturated straight-chain fatty acids. Consequently, this strain was identified as a member of the genus Zooshikella and designated as Zooshikella sp. JE-34. The pigment showed characteristics similar to prodigiosin, a well-known red pigment previously detected in Serratia marcescens. The antimicrobial activity of Zooshikella sp. JE-34 bacterial pigment was tested against 18 microorganisms, which were fish and human pathogens. The Zooshikella sp. JE-34 red pigment showed high antimicrobial activity against Streptococcus iniae, S. parauberis, S. mutans, Staphylococcus aureus, and Propionibacterium acnes.
Characterization of a Fibrinolytic Enzyme Produced by Bacillus subtilis MJ-226 Isolated from Meju
Lim, Sung-Mee ;
The Korean Journal of Microbiology, volume 45, issue 4, 2009, Pages 377~384
Among 27 Bacillus sp. isolated from Meju, a traditional Korean soybean fermented food, a strain MJ-226 was selected due to its strong fibrinolytic activity, and it was identified to be Bacillus subtilis MJ-226 according to morphological and biochemical characterization and sugar utilization. The fibrinolytic enzyme of B. subtilis MJ-226 was maximally produced by cultivating in the Tryptic Soy Broth (TSB) for 24~26 h at
, and the enzymes activity was promoted with adding glucose, fructose, peptone or yeast extract to TSB. The fibrinolytic enzyme was stable at the range of pH from 6.0 to 8.0, and between 35 and
. Also, when the crude enzyme was exposed to various metal ions and chemical inhibitors for 12 h, the enzyme stability was maintained by
, KCl, and NaCl. However, the stability was destroyed by treatment with
, and the enzyme was unstable in the presence of chemical inhibitors such as iodoacetic acid, leupeptin, phenylmethanesulphonyl fluoride (PMSF), sodium dodecyl sulfate (SDS), thiourea, trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid (CDTA) and ethylenediaminetetraacetic acid (EDTA).
Cellular Growth Traits and Detection of Acetaldehyde Dehydrogenase from Chlorella pyrenoidosa
Lee, June-Woo ;
The Korean Journal of Microbiology, volume 45, issue 4, 2009, Pages 385~390
To investigate the cellular growth traits of a photosynthetic green algae, Chlorella pyrenoidosa, several tests upon a culture temperature, a culture time, the influence of nutrient and the intensity of illumination were executed. Using growth chamber, some optimal conditions for the culture of algae were as follows: The culture temperature was about
, the culture time about 4 days, and the cellular growth of algae was in proportioned to the concentration of nutrient such as nutrient broth. And the more the intensity of illumination was increased, the more the algal cell showed good growth. And then, the activity of enzyme degrading acetaldehyde was also studied using HPLC from the same strain. This enzyme was dependent on
. And showed its optimal pH around on 9.0, and also its optimal temperature around at
. The operational conditions of HPLC were as follows: Column, ODS-Hypersil ; mobile phase, 50% (v/v) acetonitrile.
Changes in Yeast Cell Number, Total Acid and Organic Acid during Production and Distribution Processes of Makgeolli, Traditional Alcohol of Korea
Lee, Teug-Jae ; Hwang, Dae-Youn ; Lee, Chung-Yeol ; Son, Hong-Joo ;
The Korean Journal of Microbiology, volume 45, issue 4, 2009, Pages 391~396
This study was carried out to investigate the changes in yeast cell number, organic acid and total acid during the fermentation and distribution processes for enhancement of preservation of Makgeolli. Organic acids, including lactic acid, succinic acid, malic acid and citric acid, were increased with fermentation time, while oxalic acid, phosphoric acid and acetic acid were not detected, respectively. Production of organic acids leaded to pH reduction in Makgeolli. In case of Makgeolli kept at
, there was no change in organic acids until 20 days. On the other hand, when observing the change in organic acid of Makgeolli kept at
, concentration of lactic acid was decreased, while citric acid was not detected from the beginning of storage. However, acetic acid was detected from 10th day and rapidly increased at the 25th day. Therefore, it is suggested that the current expiration date (10 days in a cooler) could be extended.
Identification and Antioxidant Activity of Marine Actinomycetes Streptomyces sp. ACT-1
Kim, Man-Chul ; Kim, Ju-Sang ; Kim, Yun-Beom ; Harikrishnan, Ramasamy ; Han, Yong-Jae ; Heo, Moon-Soo ;
The Korean Journal of Microbiology, volume 45, issue 4, 2009, Pages 397~403
For the research of the natural antioxidant from marine sources, an antioxidant-producing marine actinomycetes was isolated from sea water in Jeju coastal area. The strain was identified based on 16S rDNA sequencing, the morphology by a method of scanning electron microscopy, physiological and biochemical characteristics and cellular fatty acid analysis. The isolated strain ACT-1 cell size was
and gram positive, aerobic, nonmotile, substrate mycelium are red and gray aerial mycelium. 16S rRNA sequence analysis showed that were Gram-positive bacteria grouped on Streptomyces genus. Results of cellular fatty acid analysis showed that major cellular fatty acids were
cis 9 (11.96%),
anteiso (10.99%). Finally, strain was identified Streptomyces sp. ACT-1. The antioxidant activity of methanol extract from Streptomyces sp. ACT-1 was evaluated by measuring DPPH, hydroxyl, and alkyl radical scavenging activity using an electron spin resonance (ESR) spectrometer. DPPH radical scavenging activity of SBME-1 (Streptomyces broth methanol extract) was 67% at
/ml. Hydroxyl radical scavenging activity of SBME-1 was 84% at
/ml. Alkyl radical scavenging activity of SBME-1 was 71% at
The Physicochemical Stabilities and Biological Activities of Pigment Extracts from Pseudoalteromonas sp. Ju11-1 and Pseudoalteromonas sp. Ju14
Park, Jin-Sook ; Cho, Hyun-Hee ; Kang, Myung-Hee ;
The Korean Journal of Microbiology, volume 45, issue 4, 2009, Pages 404~410
We investigated the physicochemical stabilities and biological activities of ethanol- extracted pigment from marine bacteria Pseudoalteromonas sp. Ju11-1 and Pseudoalteromonas sp. Ju14. The bacterial pigment of strain Ju11-1 was very stable at pH 5.0 below
. The stability of the pigment showed higher stability in the presence of metal ions such as
. The pigment has activity of free-radical scavenging (
/ml) and the protective antioxidant effect (
/ml) against DNA damage in human lymphocytes. The bacterial pigment of strain Ju14 was very stable at pH range between 4.0 and 8.0 below
. In the presence of light, the pigment was also very stable, showing more than 90 percent of remaining absorbance during 14 days at
. The stability of the pigment, when metal ions were present, showed higher stability in all examined metal ions except for
, especially in the presence of
. The pigment has activity of freeradical scavenging (
/ml) and the protective antioxidant effect (
/m) against DNA damage in human lymphocytes. The result indicates that the bacterial pigments from marine bacteria, Pseudoalteromonas sp. Ju11-1 and Pseudoalteromonas sp. Ju14 showed higher physicochemical stability and significant effects for reduction in oxidative DNA damage. Therefore, the results suggest that these bacterial pigments could be used as a natural colorant having the advantages of antioxidant.
Bioleaching of Mn(II) from Manganese Nodules by Bacillus sp. MR2
Choi, Sung-Chan ; Lee, Ga-Hwa ; Lee, Hong-Keum ;
The Korean Journal of Microbiology, volume 45, issue 4, 2009, Pages 411~415
Some microorganisms are capable of leaching Mn(II) from nonsulfidic manganese ores indirectly via nonenzymatic processes. Such reductive dissolution requires organic substrates, such as glucose, sucrose, or galactose, as a source of carbon and energy for microbial growth. This study investigated characteristics of Mn(II) leaching from manganese nodules by using heterotrophic Bacillus sp. strain MR2 provided with corn starch as a less-expensive substrate. Leaching of Mn(II) at 25.6 g Mn(II)
was accompanied with cell growth, but part of the produced Mn(II) re-adsorbed onto residual
particles after 24 h. Direct contact of cells to manganese nodule was not necessary as a separation between them with a dialysis tube produced similar amount [24.6 g Mn(II)
]. These results indicated an involvement of extracellular diffusible compound(s) during Mn(II) leaching by strain MR2. In order to optimize a leaching process we tested factors that influence the reaction, and the most efficient conditions were
, pH 5~7, inoculum density of 1.5~2.5% (v/v), pulp density of 2~3 g/L, and particle size <75
. Although Mn(II) leaching was enhanced as particle size decrease, we suggest <212
as a proper size range since more grinding means more energy consumption The results would help for the improvement of bioleaching of manganese nodule as a less expensive, energy-efficient, and environment-friendly technology as compared to the existing physicochemical metal recovery technologies.
Effect of Culture Broth of Cordyceps militaris on Recovery of Mice Hepatic Damage Caused by Benzo(
Jo, Sung-Jun ; Lee, Tae-Hee ; Kim, Jin-Man ; Han, Yeong-Hwan ;
The Korean Journal of Microbiology, volume 45, issue 4, 2009, Pages 416~418
The hepatoprotective effect of Cordyceps militaris culture broth was determined using HaM/ICR strain mice. Compared to control, the intra-peritoneal injection of benzo(
)P) remarkably increased the activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in the serum and the level of lipid peroxide (LPO) in liver tissue, which mean the liver was damaged by B(
)P. However, compared to B(
)P, oral administration of C. militaris culture broth showed decrement of AST, ALT, and LPO activities and increment GST activity and GSH level in liver tissue. These suggest that C. militaris culture broth recovered hepatic damage induced by B(
Expression of the lux Genes in Escherichia coli for the Basis of Development of Biosensor
Cho, Mi-Mi ; Kim, Young-Doo ; Kang, Kyung-Sook ; Kim, Sook-Kyung ; Yang, In-Chul ; Park, Sang-Ryoul ; Lee, Chan-Yong ;
The Korean Journal of Microbiology, volume 45, issue 4, 2009, Pages 419~424
To provide the basis of biosensor based on the lux genes from bioluminescent bacteria of Photobacterium leiognathi and Vibrio harveyi, we test the expression of lux genes in several strains of Escherichia coli. The expression of the recombinant plasmid of PlXba.pT7-3, containing all lux genes requiring for light emission without adding substrate, in E. coli 43R was so strong to see the blue-green light in single colony as well as in the alginate immobilized cell. In addition, the light intensity was decreased by adding heavy metal ion such as cadmium and zinc ions. These result raise the possibility that a biosensor can be developed using the lux genes system.
Detection of plcR-papR Genes by PCR in Identifying Enterotoxin Genes-Harboring Bacillus cereus Strains
Yun, Suk-Hyun ; Kim, Yong-Sang ; So, Soon-Ku ; Jeong, Do-Yeon ; Hahn, Kum-Su ; Uhm, Tai-Boong ;
The Korean Journal of Microbiology, volume 45, issue 4, 2009, Pages 425~429
Identification of virulent Bacillus cereus strains was examined by PCR using primers specific for the detection of plcR-papR, which encode regulatory proteins controlling the transcription of virulence factors in B. cereus. Total 96 strains of B. cereus that carried at least one of diarrheal toxin genes including hblACD, nheABC, and cytK showed all positive PCR products, while other 48 Bacillus strains that lacked the toxin genes were plcRpapR-negative. This PCR method targeting the plcR-papR genes appears to be simple and effective in identifying the enterotoxin genes-harboring B. cereus strains.
Heterogeneity Analysis of the 16S rRNA Gene Sequences of the Genus Vibrio
Ki, Jang-Seu ;
The Korean Journal of Microbiology, volume 45, issue 4, 2009, Pages 430~434
Bacterial 16S rRNA gene sequences have been widely used for the studies on molecular phylogeny, evolutional history, and molecular detections. Bacterial genomes have multiple rRNA operons, of which gene sequences sometimes are variable. In the present study, heterogeneity of the Vibrio 16S rRNA gene sequences were investigated. Vibrio 16S rRNA sequences were obtained from GenBank databases, considering the completion of gene annotation of Vibrio genome sequences. These included V. cholerae, V. harveyi, V. parahaemolyticus, V. splendidus, and V. vulnificus. Chromosome 1 of the studied Vibrio had 7~10 copies of the 16S rRNA gene, and their intragenomic variations were less than 0.9% dissimilarity (more than 99.1% DNA similarity). Chromosome 2 had none or single 16S rRNA gene. Intragenomic 16S rRNA genotypes were detected at least 5 types (V. vulnificus #CMCP6) to 8 types (V. parahaemolyticus #RIMD 2210633, V. harveyi #ATCC BAA-1116). These suggest that Vibrio has high heterogeneity of the 16S rRNA gene sequences.