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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 13, Issue 6 - Dec 2003
Volume 13, Issue 5 - Oct 2003
Volume 13, Issue 4 - Aug 2003
Volume 13, Issue 3 - Jun 2003
Volume 13, Issue 2 - Apr 2003
Volume 13, Issue 1 - Feb 2003
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Isolation and Characteristics of Trichoderma harzianum FJI Producing Cellulases and Xylanase
Kim, Kyoung-Cheol ; Yoo, Seung-Soo ; Oh, Young-A ; Kim, Seong-Jun ;
Journal of Microbiology and Biotechnology, volume 13, issue 1, 2003, Pages 1~8
Strain FJI, a filamentous fungus isolated from rotten wood, showed high ability to hydrolyze cellulosic materials. To identify the strain FJI, ITS sequencing analysis and morphological observation were performed. The strain FJI was identified as Trichoderma harzianum. The strain produced a large amount of CMCase, xylanase,
, and avicelase. Optimal culture conditions for the production of the enzymes, such as pH, temperature, and inoculation concentration, were initial pH 6.0-7.0,
ea-spores/ml in Mandel's medium, respectively. T.hanzianum FJI utilized various cellulosic materials and organic nitrogen sources to produce cellulases and xylanase, and also considerably a crystalline and/or insoluble material like Avicel and rice straw. The highest levels of CMCase and xylanase were 41.2 and 65.6 U/ml in 7 days of cultivation using 2.5% of carbon source (Avicel+CMC) and 0.5% of nitrogen source (peptone), respectively.
Transformation of Ginsenosides to Compound K(IH-901) by Lactic Acid Bacteria of Human Intestine
Bae, Eun-Ah ; Kim, Na-Young ; Han, Myung-Joo ; Choo, Min-Kyung ; Kim, Dong-Hyun ;
Journal of Microbiology and Biotechnology, volume 13, issue 1, 2003, Pages 9~14
When ginsenosides Rbl, Rb2, and Rc were anaerobically incubated with commercial and human intestinal lactic acid bacteria, most commercial lactic acid bacteria did not metabolize these ginsenosides to compound K. However, lactic acid bacteria, B. minimum KK-1, Bifidobacterium cholerium KK-2, and B. cuniculi K-513, isolated from human intestinal microflora transformed these ginsensosides to compound K. When the bacterial mixtures of commercial lactic acid bacteria were incubated with these ginsenosides, these compounds were not transfformed to compound K. However, when Bzfidobacterium KK-1 and KX-2 were miked, these ginsenosides were synergistically transformed to compound K. When water extract of ginseng was incubated with these mixed bifidobacteria, compound K was potently produced. Therefore, it is suggested that, if ginseng with these mixed bifidobacteria is fermented, compound K-enforced ginseng materials could be produced that show cytotoxicity against tumor cell lines.
Bacterial Community Composition of Activated Sludge Relative to Type and Efficiency of Municipal Wastewater Treatment Plants
Ahn, In-Sook ; Kim, Myeong-Woon ; La, Hyun-Joon ; Choi, Kyung-Min ; Kwon, Joong-Cheon ;
Journal of Microbiology and Biotechnology, volume 13, issue 1, 2003, Pages 15~21
Two microbial communities of activated sludge in the same municipal wastewater, but treated with different systems, were studied and compared using molecular microbiological approaches. The bacterial 16S rDNA sequences from 124 clones were analyzed, however, the majority of them were not closely related to any known species, and found to belong to 8 different phylogenetic groups and 3 different unidentified groups. The relative frequencies of each group were similar between the two microbial communities. Fingerprinting using terminal restriction fragment length polymorphism (T-RFLP) showed that the putative Nitrospira-related populations were more diverse and quantitatively higher in the KNR process system than in the other system using a conventional activated sludge process. The relationship between the bacterial community composition and the higher removal efficiency of nitrogen and phosphorus in the KNR process is discussed.
Increase of Conjugated Linoleic Acid Level in Milk Eat by Bovine Feeding Regimen and Urea Fractionation
KIM, YOUNG JUN ; KI WON LEE ; HYONG JOO LEE ;
Journal of Microbiology and Biotechnology, volume 13, issue 1, 2003, Pages 22~28
Increasing conjugated linoleic acid (CLA) content in dairy products has been a research Interest due to the potential health benefits resulted from consuming CLA. Attempts were made to obtain high level natural CLA containing fatty acid fractions from milk fat through bovine feeding of sunflower oil (SO) and urea fractionation. SO feeding changed the fatty acid profile of milk fat. increasing the CLA content five-fold at eight weeks of trial. Milk fat obtained from S0-fed cows was hydrolyzed to free fatty acids, which were then fractionated with urea at various ratios. The profiles of fatty acids were also greatly influenced by urea fractionation. Long-chain unsaturated fatty acids, Including CLA, were concentrated in milk fat after the fractionation, whereas saturated long-chain counterparts were eliminated. The highest level of CLA was achieved by the fractionation at 2:1 urea/fatty acid ratio (UFR2). CLA level was elevated 2.5-fold, and the Cl8:1/C18:0 fatty acid ratio was increased 120 times after the fractionation. The level of CLA in high CLA-milk fat (24mg/g fat) obtained from the feeding study was further increased through urea fractionation up to 52mg/g fat, 10 folds as high as CLA in the control milk fat (5mg/g fat).
Degradation of Salicylic Acid by Free and Immobilized Cells of Pseudomonas sp. Strain NGK1
Patil, Neelakanteshwar-K. ; Sharanagouda, U. ; Niazi, Javed-H. ; Kim, Chi-Kyung ; Karegoudar, Timmanagouda-B. ;
Journal of Microbiology and Biotechnology, volume 13, issue 1, 2003, Pages 29~34
A Pseudomonas sp. strain NGK1 (NCIM 5120) capable of utilizing salicylate was immobilized in alginate and polyurethane foam (PUF). The degradation rate of salicylate by freely suspended cells was compared with the degradation rate by immobilized cells. In an initial 20 and 40 mM salicylate, free cells (
) degraded to 16 and 14 mM, alginate-entrapped cells degraded to 18 and 26 mM, and PUF-entrapped cells degraded to 20 and 32 mM salicylate, respectively, in batch cultures. The alginate-and PUF-entrapped cells were used in repeated batch and continuous culture systems. The efficiency of both the immobilized systems f3r the degradation of salicylate was compared. It has been observed that the PUF-entrapped cells could be reused for more than 20 cycles whereas alginate-entrapped cells could be reused for a maximum of only 12 cycles, after which a decrease in degradation rat was observed with the initial 20 and 40 mM salicylate. The continuous degradation of sallcylate by freely suspended cells showed a negligible degradation rate of salicylate when compared with immobilized cells. With the immobilized cells in both alginate and polyurethane foam, the degradation rate increased with an increase in the dilution rate up to
for 20 mM, and
for 40 mM salicylate. The results revealed that PUF-entrapped cells were more efficient for the degradation of salicylate than alginate-entrapped cells and freely suspended cells.
Cloning and Characterization of a Bifunctional Cellulase-Chitosanase Gene from Bacillus lichenformis NBL420
HONG, IN-PYO ; HONG-KI JANG ; SHIN-YOUNG LEE ; SHIN-GEON CHOI ;
Journal of Microbiology and Biotechnology, volume 13, issue 1, 2003, Pages 35~42
A 1,3 kb cellulase gene encoding novel bifunctional cellulase-chitosanase activity was cloned from biopolymer-producing alkali-tolerant B. lichenformis NBL420 in E. coli. A recombinant cellulase-chitosanase, named CelA, was expressed and purified to homogeneity. The activity staining and the enzymatic characterization of the purified CeIA revealed bifunctional activities on carboxymethyl cellulose (CMC) and glycol-chitosan. The similar characteristics of the enzymatic activities at the optimum pH, optimum temperature, and thermostability Indicated that CelA used a common catalytic domain with relaxed substrate specificity. A comparison of the deduced amino acids in the N-terminal region revealed that the mature CelA had a high homology with the previously identified bifunctional cellulase-chitosanase of Myxobacter sp. AL- 1.
Biotransformation of a Fungicide Ethaboxam by Soil Fungus Cunninghamella elegans
PARK, MI-KYUNG ; KWANG-HYEON LIU ; YOONGHO LIM ; YOUN-HYUNG LEE ; HOR-GIL HUR ; JEONG-HAN KIM ;
Journal of Microbiology and Biotechnology, volume 13, issue 1, 2003, Pages 43~49
Metabolism of a new fungicide ethaboxam by soil fungi was studied. Among the fungi tested, Cunninghamelia elegans produced metabolites from ethaboxam, which were not found in the control experiments. M5, a major metabolite from ethaboxam was firmly identified as N-deethylated ethaboxam by LC/MS/MS and NMR. N-Deethylated ethaboxam has been found as a single metabolite in in vitro metabolism with rat liver microsomes. Ml was proved to be 4-ethyl-2-(ethylamino)-1,3-thiazole-5-carboxamide (ETC) by comparing with the authentic compound. In addition, M2, M3, and M4, and M6 were tentatively Identified by LC/MS/MS as hydroxylated and methoxylated ethaboxams, respectively. Production of the major metabolite, N-deethylated ethaboxam, by the fungus suggested that C. elegans would be an efficient eukaryotic microbial candidate for evaluating xenobiotic-driven mammalian risk assessment.
Biotoxic Cyanobacterial Metabolites Exhibiting Pesticidal and Mosquito Larvicidal Activities
Kumar, Ashok ; Dhananjaya P. , Singh ; Tyagi, M.B. ;
Journal of Microbiology and Biotechnology, volume 13, issue 1, 2003, Pages 50~56
A freshwater bloom-forming cyanobacterium, Microcystis aeruginosa, and local soil isolate Scytonema sp. strain BT 23 were demonstrated to contain biotoxic secondary metabolites with pesticidal and mosquito larvicidal activities. A purified toxic constituent from M aeruginosa showed an absorption maximum at 230 nm and its toxicity symptoms, Rf value on TLC, and retention time observed ill an HPLC analysis were similar to those of the hepatotoxic heptapeptide microcystin-LR. The bioactive constituent of the Scytonema sp. was less polar in nature and exhibited two peaks at 240 and 285 m. When applied to two cruciffrous pests, Pieris brassicae and Plutella flostella, the crude extracts and toxic principles from the two cyanobacteria showed significant antifeedant activity in a no-choice bioassay, and at higher concenuations exhibited contact toxicity to the insect larvae. The purified toxin from M. aeruginosa was found to be more effective and produced 97.5 and
larval mortality in the two pests, fo11owing 2 h of toxin treatment at a concentration of
Per leaf disc (2.5 cm dia.). Meanwhile, similar treatment with the purified toxin from Sytonema sp. stain BT 23 only produced 73 and
mortality in the two pests. The cyanobacterial constituents also showed significant activity against Culex and Anopheles larvae. The M. aeruginosa toxin (
) caused 98.2 and
mortality in the Culex and Anopheles larvae, respectively, while the purified toxin from the Sytonema sp. was less toxic and only produced a 96.3 and
mortality, respectively, at a much higher concentration (
). Accordingly, the current results point to certain hitherto unknown biological properties of cyanobacterial biotoxins.
Uniqueness of Microbial Cutinases in Hydrolysis of p-Nitrophenyl Esters
KIM, YANG-HOON ; JEEWON LEE ; SEUNG-HYEON MOON ;
Journal of Microbiology and Biotechnology, volume 13, issue 1, 2003, Pages 57~63
Using fungal (Fusarium solani f. pisi) and bacterial (Pseudomonas mendocina) cutinases, the initial hydrolysis rate of p-nitrophenyl esters was systematically estimated for a wide range of enzyme and substrate concentrations using a 96-well microplate reader. Both cutinases exhibited a high substrate specificity; i.e. a high hydrolytic activity on p-nitrophenyl butyrate (PNB), yet extremely low activity on p-nitrophenyl palmitate (PNP). When compared to the hydrolysis of PNB and PNP by other hydrolases [lipases and esterases derived from different microbial sources, such as bacteria (Pseudomonas cepacia, Psedomonas furescens, Baciilus stearothermophilus), molds (Aspeillus niger, mucor miehei), and yeasts (Candida rugosa, Candida cylindracea)], the above substrate specificity would seem to be a unique characteristic of cutinases. Secondly, the hydrolytic activity of the cutinases on PNB appeared much faster than that of the other hydrolytic enzymes mentioned above. Furthermore, the current study proved that even when the cutinases were mixed with large amounts of other hydrolases (lipases or esterases), the Initial hydrolysis rate of PNB was determined only by the cutinase concentration for each PNB concentration. This property of cutinase activity would seem to result from a higher accessibility to the substrate PNB, compared with the other hydrolytic enzymes. Accordingly, these distinct properties of cutinases may be very useful in the rapid and easy isolation of various natural cutinases with different microbial sources, each of which may provide a novel industrial application with a specific enzymatic function.
Characterization of a Tacky Poly(3-Hydroxyalkanoate) Produced by Pseudomonas chlororaphis HS21 from Palm Kernel Oil
YUN, HYE SUN ; DO YOUNG KIM ; CHUNG WOOK CHUNG ; HYUNG WOO KIM ; YOUNG KI YANG ; YOUNG HA RHEE ;
Journal of Microbiology and Biotechnology, volume 13, issue 1, 2003, Pages 64~69
Pseudomonas chlororaphis HS21 was isolated from a soil sample and found to produce medium-chain-length polyhydroxyalkanoates (MCL-PHAs) using palm kernel oil (PKO) as the sole carbon source. Up to 3.3 g/1 dry cell weight containing
MCL-PHA was produced, when the strain was grown for 21 h in a jar fermentor culture containing 5 g/1 PKO. The polymer produced from PKO consisted of unsaturated monomers of
3-hydroxy-5,8,-cis, cis-tetradecadienoate as well as saturated even-carbon number monomers ranging from
, as determined by GC and El GC/MS The PHA was a transparent, sticky material at room temperature. A differential scanning calorimetric analysis revealed that the polymer was amorphous with a
glass transition temperature. The number average molecular weight and polydispersity index of the PHA were 83,000 and 1.53, respectively. Although the PHA was practically biodegradable, its degradability was lower than that of poly(3-hydroxyoctanoate) based on a comp:trison of the clear zones formed by growing PHA depolymerase-producing bacteria on an agar plate containing the respective polymers.
Benzene Biodegradation Using the Polyurethane Biofilter Immobilized with Stenotrophomonas maltophilia T3-c
Kwon, Heock-Hoi ; Lee, Eun-Young ; Cho, Kyung-Suk ; Ryu, Hee-Wook ;
Journal of Microbiology and Biotechnology, volume 13, issue 1, 2003, Pages 70~76
The benzene removal characteritics of the polyurethane (PU) biofilter immobilized with S. maltophilia T3-c, that could efficiently degrade benzene, was investigated. Maximum capacity to eliminate benzene was maintained at
when space velocity (SV) ranged from 100 to
-1/, however, it decreased sharply to
as SV increased to
. The critical elimination capacities that guaranteed
removal of inlet loading of the PU biofilter were determined to be 70,30, and
at SV 100,200, and
, respectively. Based on the result of a kinetic analysis of the PU biofilter, maximum benzene elimination velocity (
and saturation constant (
of benzene (
). This study suggests that the biofilter utilizing S. maltophilia T3-c and polyurethane is a very promising technology for effectively degrading benzene.
Purification of Chitinase from an Antagonistic Bacterium Bacillus sp.7079 and Pro-Inflammatory Cytokine Gene Expression by PCTC
Han, Ok-Kyung ; Lee, Eun-Tag ; Lee, Young-Sun ; Kim, Sang-Dal ;
Journal of Microbiology and Biotechnology, volume 13, issue 1, 2003, Pages 77~84
Chitinase was purified from an antagonistic bacterium Bacillus sp. 7079 by ammonium sulfate precipitation, QAE-Sephadex anion exchange chromatography, Sephadex G-100 gel filtration, and SP-Sephadex cation exchange chromatography. The molecula. weight of purified chitinase (PC-1) was approximately 66.5 kDa on SDS-PACE. PC-1 exhibited optimum pH and temperature of pH 7.5 and
, respectively. More than
of PC-1 was stable at pH 5.0 to 9.0, and more than
inhibited the chitinase activity about
, and EDTA and p-CMB by about
inhibited the activity up to
value of PC-1 was 1.215 mg/ml with colloidal chitin as a substrate. We also investigated the effect of PC-1 treated chitin (PCTC) on the pro-inflammatory cytokine gene expression in macrophage RAW 264.7 cells. The expression of IL-
mRNA gene was investigated using reverse transcriptase polymerase chain reaction (RT-PCR). IL-
mRNA were induced by the treatment of PCTC and chitin only in RAW 264.7 cells. These expressions were induced as early as 2 h and sustained up to 24 h in RAW 264.7 cells. IL-
mRNA were more strongly expressed by the treatment of PCTC than chitin treatment alone in RAW 264.7 cells.
Effect of Trehalose Accumulation on the Intrinsic and Acquired Thermotolerance in a Natural Isolate, Saccharomyces cerevisiae KNU5377
PAIK, SANG-KYOO ; HAE-SUN YUN ; HO-YONG SOHN ; INGNYOL JIN ;
Journal of Microbiology and Biotechnology, volume 13, issue 1, 2003, Pages 85~89
The difference in the thermotolerance between Saccharomyces cerevisiae KNU5377 and ATCC24858 was compared by assaying the amounts of trehalose accumulated under growth and heat shock conditions. Both strains exhibited similar trehalose accumulation during the growth period, but an intrinsic thermotolerance was much higher in KNU5377 than in the control strain. This result implied that some strain-specific characteristics of KNU5377, other than trehalose accumulation, primarily were responsible fur its higher intrinsic thermotolerance. Heat shock at
for 90 min to the exponentially growing cells resulted in the maximum level of trehalose In both strains. Trehalose accumulated at least twice more in KNU5377 by the heat shock than in the control, due to the maintenance of its neutral trehalase activity even after the heat shock. Consequently, the Increase of acquired thermotolerance in both strains correlated with an increase in the trehalose content in each strain. In conclusion, KNU5377 exhibited a well-modulated trehalose-related mechanism to accumulate more trehalose by means of maintaining neutral trehalase activity after heat shock than the control strain, thereby contributing to its acquired thermotolerance.
Nuclear Magnetic Resonance Studies of Acetic Acid Inhibition of Ethanol Production by Strains of Zymomonas mobilis
Kim, In-Seop ; Barrow, Kevin D. ; Rogers, Peter L. ;
Journal of Microbiology and Biotechnology, volume 13, issue 1, 2003, Pages 90~98
Nuclear Magnetic Resonance (
NMR) and metabolic studies were carried out on an acetic acid tolerant mutant, Zymomonas mobilis
, and compared to those of the parent strain, Z. mobilis ZM4, to evaluate possible mechanisms of acetic acid resistance. This investigation was initiated to determine whether or not the mutant strain might be used as a suitable recombinant host far ethanol production from lignocellulose hydrolysates containing various inhibitory compounds.
showed multiple resistance to other lignocellulosic toxic compounds such as syringaldehyde, furfural, hydroxymethyl furfural, vanillin, and vanillic acid. The mutant strain was resistant to higher concentrations of ethanol or lower pH in the presence of sodium acetate, compared to ZM4 which showed more additive inhibition. in vivo
NMR studies revealed that intracellular acidification and de-energization were two mechanisms by which acetic acid exerted its inhibitory effect. For
, the internal pH and the energy status were less affected by sodium acetate compared to the parent strain. This resistance to pH change and de-energization caused by acetic acid is a possible explanation for the development of resistance by this strain.
Genotoxicity Assay Using Chromosomally-Integrated Bacterial recA::Lux
Min, Ji-Ho ; Gu, Man-Bock ;
Journal of Microbiology and Biotechnology, volume 13, issue 1, 2003, Pages 99~103
An Escherichia coli strain containing the recA promoter that fused to the luxCDABE operon originating from Photorhabdus luminescens was shown to respond sensitively to genotoxic stresses. Two different recombinant bacteria, one (DPDI 657) harboring a plasmid with the recA promoter that fused to the luxCDABE operon, and the other (DPD1710) containing a chromosomally-integrated recA promoter that fused with luxCDABE, were compared and it was found that the sensitivity of 'the two strains was significantly different in terms of their bioluminescent level, response time, and the minimum detectable concentration of a chemical causing DNA damaging stress. DPDI 710, with a chromosomally-integrated single copy, generally led to lower basal luminescence levels, faster responses, increased response ratios, and an enhanced sensitivity to mutagens, when compared to DPD 1657 with a multi-copy plasmid.
Enhanced Production of Benzoylformate Reductase in Enterococcus faecalis under Oxidative Stress Established by Natural Electron Carriers
Baik, Sang-Ho ; Cho, Pan-Ki ; Kim, Mee-Hae ; Yun, Sei-Eok ;
Journal of Microbiology and Biotechnology, volume 13, issue 1, 2003, Pages 104~109
Enhancement of the production of benzoylformate reductase (BFR) was attempted under oxidative stress established by natural electron carriers. -lipoic acid (LA), flavin adenine dinucleotide (FAD), and ubiquinone (UQ) did not inhibit growth of E. faecalis when their concentrations were as high as
and methyl viologen (
) inhibited the bacterial growth. BFR activity in the bacterial extract had increased rapidly after 1 h of cultivation after the addition of
of natural electron carriers, and the activity was maintained during further cultivation. BFR activity of the cells treated with the natural electron carriers was
higher than that of the control. In the presence of
, BFR activity increased, reaching the highest activity at about 5 h cultivation, and then decreased with further cultivation. It seems that natural electron carriers not only stimulate the induction of BFR, but also stabilize the enzyme. BFR was hardly affected by LA, FAD, and UQ, while
inactivated the crude enzyme. The decrease of BFR activity in the presence of
might be ascribed to inactivation of the enzyme by the oxidants.
Identification and Characterization of Coronatine-Producing Pseudomonas syringae pv. actinidiae
Han, Hyo-Shim ; Koh, Young-Jin ; Hur, Jae-Seoun ; Jung, Jae-Sung ;
Journal of Microbiology and Biotechnology, volume 13, issue 1, 2003, Pages 110~118
Pseudomonas syringae pv. actinidiae strains, which cause canker disease in kiwifruit, were collected from kiwifruit orchards in Korea and identified using biochemical and physiological tests. The nucleotide sequences of the 16s rDNA and 16s-23s internally transcribed spacer of the isolates were found to be Identical to those of' the pathotype strain, Kwl 1, of P syringae pv. actinidiae. Remarkably, no coding sequence for phaseolotoxin biosynthesis or phaseolotoxin- resistant ornithine carbamoyltransferase was found by PCR amplification in any of the new Korean isolates of pseudomonas syringae pv. actinidiae, although this was clearly identified in the control pathotype Kwl 1 reference strain. In contrast, three primer sets derived from the coronatine biosynthetic gene cluster and DNA from the Korean strains yielded amplified DNA fragments of the expected size. A sequence analysis of the PCR products revealed that P. syringae pv. actinidiae and the Korean strains of pv. actinidiae contain coronafncate ligase genes (cfl)with identical sequences, whereas their. corR genes exhibited 91% sequence similarity. The production of coronatine, instead of phaseolotoxin, by the Korean strains of P. syringae pv. actinidiae was confirmed by a bioassay using reference pathovars known to produce coronatine and phaseolotoxin. The genes for coronatine biosynthesis in the Korean strains of P. syringae pv. actinidiae were found to be present on plasmids.
Identification of Lactic Acid Bacteria in Kimchi Using SDS-PAGE Profiles of Whole Cell Proteins
Kim, Tae-Woon ; Jung, Sang-Hoon ; Lee, Ji-Yeon ; Choi, Sun-Kyu ; SUN-HEE-PARK ; JAE-SUN-JO ;
Journal of Microbiology and Biotechnology, volume 13, issue 1, 2003, Pages 119~124
This study was conducted to evaluate the practical usefulness of the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PACE) fingerprinting of whole cell proteins far the identification of lactic acid bacteria in Kimchi. SDS- PACE of whole cell proteins of the reference strains and lactic acid bacteria isolated from Kimchi yielded differential banding patterns that were highly specific fingerprints, thus making it possible to identify. Identification of the isolates from Kimchi was achieved by comparing the SDS-PAGE fingerprints of isolates to those of reference strains. In addition, the reliability of SDS-PAGE was examined by comparing the results with those of the APL 50 CHL system assay and 16S rRNA gene sequence. SDS-PACE assay showed a different identity to reference strains, while the APL 50 CHL system and 16S rRNA gene sequence could not distinguish a few strains. Therefore, SDS-PAGE of the whole cell proteins is a specific and a reliable method that will be useful for the identification of lactic acid bacteria in Kimchi to the species level, and can be used as an alternative or complementary identification method.
Chemical Properties and Physiological Activities of Synnemata of Beauveria bassiana
Yoon, Cheol-Sik ; Yu, Kwang-Won ; Bae, Song-Hwan ; Song, Hyuk-Hwan ; Park, Hyun-Soo ; Lee, Chan ;
Journal of Microbiology and Biotechnology, volume 13, issue 1, 2003, Pages 125~133
Chemical properties and physiological activities of the freeze-dried synnemata of Beauveria bassiana were examined. A proximate analysis showed that the synnemata consisted mainly of carbohydrate (49.86%), protein 11.36%), and a moisture content of 30.64%. It contained a low amount of crude ash (4.76%) and fat (3.38%). The carbohydrate was composed mainly of mannose (52.3%), galactose (31.5%), glucose (13.2%), and rhamnose (3%). Trace amounts of arabinose, xylose, and fructose were present. Major amino acids In the synnemata were glutamic acid, glycine, aspartic acid, arginine, threonine, alanine, valine, leucine, lysine, and aspartic acid with the amounts of 30.42, 25.22, 17.17, 15.12, 12.65, 15.23, 12.47, 11.47, 14.24, and 17.17 mg/g, respectively. Among extracts from the synnemata, the hot-water extract showed 67% of anticomplementary activity compared to that of the positive control, followed by ethyl acetate extract (17%) and methanol extract (15%). The hot-water extract also had anticoagulant activity with 55 sec of coagulating time and this fraction exhibited the most potent Intestinal immune system modulating activity. The methanol extract showed the highest inhibitory activity (25%) on the 12-O-tetradecanoyl phorbol-13-acetate-induced superoxide (
) generation, followed by hot-water extract (18%) and ethyl acetate extract (10%). The data in the present study indicate that the extract of Beauveria bassiana synnemata contains some healthful chemical ingredients and it could provide beneficial physiological activities. These features of the synnemata should be of interest to the food industry as well as other industrial fields.
The Importance of Tyr-475 and Glu-506 in
-Galactosidase from L. lactis ssp.lactis 7962
Yang, Eun-Ju ; Lee, Jung-Min ; Lee, Hyong-Joo ; Kim, Jeong-Hwan ; Chung, Dae-Kyun ; Lee, Jong-Hoon ; Chang, Hae-Choon ;
Journal of Microbiology and Biotechnology, volume 13, issue 1, 2003, Pages 134~138
The secondary and tertiary structures of
-galactosidase from L. lactis ssp. lactis 7962 were designed using Nnpredict and Sybyl version 6.3. By using site-directed mutagenesis, the mutated enzymes, Tyr-475-phe and Glu-506-Asp, were generated based on the structural modeling of L. lactis ssp. lactis 7962. The enzymes Tyr.-475-Phe and Glu-506-Asp had <
of the activity of the native enzyme with ONPG as substrate. The
values of the mutated enzymes were greatly reduced (1,800~40,000-1314) compared with the value for the native
-galactosidase. However, the
values of Tyr-475-Phe and Glu-506-Asp with ONPG, PNPG, PNPF, and PNPA were not significantly different from those of the native enzyme. The results obtained support the suggestion that Tyr-475 and Glu-506 constitute very important parts of the catalytic machinery of the
Cloning, Analysis, and Expression of the Gene for Thermostable Polyphosphate Kinase of Thermus caldophilus GK24 and Properties of the Recombinant Enzyme
Hoe, Hyang-Sook ; Lee, Sung-Kyoung ; Lee, Dae-Sil ; Kwon, Suk-Tae ;
Journal of Microbiology and Biotechnology, volume 13, issue 1, 2003, Pages 139~145
The gene encoding Thermus caldophilus GK24 polyphosphate kinase (Tca PPK) was cloned and sequenced. The gene contains an open reading frame encoding 608 amino acids with a calculated molecular mass of 69,850 Da. The deduced amino acid sequence of Tca PPK showed a 40% homology to Escherichia coli PPK, and
to Klebsiella aerogenes PPK. The Tca ppk gene was expressed under the control of the T7lac promoter on pET-22b(+) in E. coli and its enzyme was purified about 70-fold with
yield, following heating and HiTrap chelating HP column chromatography. The native enzyme was found to have an approximate molecular mass of 580,000 Da and consisted of eight subunits. The optimum pH and temperature of the enzyme were 5.5 and
, respectively. A divalent cation was required for the enzyme activity, with
being the most effective.
Inhibition of Asexual Speculation and Growth of Aspergillus niger and Aspergillus oryzae by Propylamine
SONG, MYUNG HOON ; KUPPUSAMY SELVAM ; HYO-YOUNG JEONG ; KEON-SANG CHAE ;
Journal of Microbiology and Biotechnology, volume 13, issue 1, 2003, Pages 146~148
Effects of propylamine on conidial head formation and growth of Aspergillus niger and Aspergillus oryzae were analyzed. Propylamine inhibited conidial head formation in these two fungi, and the inhibitory effect of propylamine was not suppressed by the addition of potassium chloride at high concentration, which promotes conidial head formation in A. nidulans and A. oryzae. Propylamine also inhibited the growth of A. niger and A. oryzae by
, respectively, when the concentration of propylamine was
Identification and Characterization of the Vitro vulnificus Phosphomannomutase Gene
Lee, Jeong-Hyun ; Park, Na-Young ; Park, Soon-Jung ; Choi, Sang-Ho ;
Journal of Microbiology and Biotechnology, volume 13, issue 1, 2003, Pages 149~154
Numerous virulence factors such as O antigen have been proposed to account for the fulminating and destructive nature of V. vulnificus infections. To better characterize the role of O antigen, a pmm gene encoding a phosphomannomutase was identified and cloned from V. vulnificus. The deduced amino acid sequence of the pmm was 42 to 71% similar to that reported from other Enterobacteriaceae. Functions of the pmm gene in virulence were assessed by the construction of an isogenic mutant, whose pmm gene was inactivated by allelic exchanges, and by evaluating its phenotype changes in vitro and in mice. The disruption of pmm resulted in a loss of more than 90% of phosphomannomutase, and reintroduction of recombinant pmm could complement the decrease of phosphomannomutase activity, indicating that the pmm gene encodes the phosphomannomutase of V. vulnificus. There was no difference in the
of the wild-type and the pmm mutant in mice, but the
observed by the mutant complemented with recombinant pmm were lower. Therefore, it appears that PMM is less important in the pathogenesis of V. vulnificus than would have been predicted by examining the effects of injecting purified LPS into animals, but it is not completely dispensable for virulence in mice.
Pulsed-Field Gel Electrophoresis and Mutation Typing of gyrA Gene of Quinolone-Resistant Salmonella enterica Serovar Paratyphi A Isolated from Outbreak and Sporadic Cases,1998-2002, Korea
KIM SHUKHO ; OK YOUNG LIM ; SEONG HAN KIM ; JUN YOUNG KIM ; YEON HO KANG ; BOK KWON LEE ;
Journal of Microbiology and Biotechnology, volume 13, issue 1, 2003, Pages 155~158
In early 2002, over 200 people in the city of Pusan. Korea suffered from paratyphoid fever resulting from Salmonella Paratyphi A Infection. Antimicrobial susceptibility tests and Xbal pulsed-field gel electrophoresis (PFCE) were conducted to 54 Salmonella Paratyphi A isolated from humans during the period of 1998 to 2002. Most of the isolates (
) were only nalidixic acid-resistant and
were X 1 PFGE patterns. Also, we measured the MIC of ciprofloxacin and screened gyrA mutation(5) using allele- specific PCR and restriction fragment length polymorphism (AS-PCR-RFLP). The representative 5 isolates in 2002 and 1 isolate in 2000 were
of MIC and had mutation at the 83rd codon in gyrA. These data suggest that the outbreak in the early 2002 might have been due to dissemination of the strain present In 2000. Also, decreased susceptibility to ciprofloxacin was partly due to the mutation at the 83rd codon in gyrA.
Identification of vitro vulnificus lrp and Its Influence on Survival Under Various Stresses
Jeong, Hye-Sook ; Rhee, Jee-Eun ; Lee, Jeong-Hyun ; Choi, Hyun-Kyung ; Kim, Dae-Il ; Lee, Myung-Hee ; Park, Soon-Jung ; Choi, Sang-Ho ;
Journal of Microbiology and Biotechnology, volume 13, issue 1, 2003, Pages 159~163
An lrp gene encoding a leucine-responsive regulatory protein was identified from Vitro vulnificus, and its role in the survival of the organism was assessed by analyzing the stress tolerance of the isogenic mutant, in which the lrp gene had been inactivated. The results demonstrated that Lrp contributes to the survival of V. vulnificus is dependent of the phase of growth