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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Microbiology and Biotechnology Letters
Journal Basic Information
Journal DOI :
The Korean Society for Applied Microbiology and Biotechnology
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Volume & Issues
Volume 26, Issue 6 - Dec 1998
Volume 26, Issue 5 - Oct 1998
Volume 26, Issue 4 - Aug 1998
Volume 26, Issue 3 - Jun 1998
Volume 26, Issue 2 - Apr 1998
Volume 26, Issue 1 - Feb 1998
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Acid Tolerance of the Acid-Resistant Mutant of Leuconostoc paramesenteroides Improved for Kimchi Starter.
Microbiology and Biotechnology Letters, volume 26, issue 4, 1998, Pages 275~282
To investigate the increased acid tolerance of a acid-resistant mutant Leuconostoc paramesenteroides P-100 improved as a kimchi starter, proton permeability, ATPase acitivity, glycolysis activity,
sup +/ releasement, and membrane fatty acid composition were studied and comprised with its wild type Leuconostoc paramesenteroides Pw. In the proton permeability experiment, the maximum values of the average half time (t
1/2/) of pH equilibration through the cell membrane of the Pw and the P-100 were about 6.4 min and 7.8 min in 150 mM KCI solution, respectively. In the 3% NaCl solution, the t
1/2/ values of the Pw and the P-100 were 5.5 min and 6.9 min, respectively. The values and pHs of maximal specific activities of ATPase originated from the Pw and the P-100 were 0.5 unit/mg protein and 0.78 unit/mg protein at pH 6.0, respectively. The result of pH dependence of glycolysis showed that the P-100 had higher activities than that of Pw except at pH 7.0. The releases of magnesium from the Pw and the P-100 were observed about 54.5% and 23.2% at pH 4.0 after 2 hours, respectively. The results of comparison of membrane fatty acid composition of the Pw with the P-100 showed that C
18:0/, and C
19:0,cyclo/ were major different fatty acids between two strains and the content of C
18:1/, and C
19:0,cyclo/ were 2.8%, N.D (not detected) in the Pw and 0.4%, 2.3% in the P-100. These results indicated that acid tolerance of the P-100 was significantly improved in comparison with its wild type Pw.
Isolation and Characteristics of Prodigiosin-like Red Pigment Produced by Serratia sp. KH-95.
Microbiology and Biotechnology Letters, volume 26, issue 4, 1998, Pages 283~289
A bacterial strain KH-95 producing a high concentration of red pigment was isolated from the soil. The strain KH-95 was identified as a strain of Serratia sp. based on morphological and physiological characteristics. The optimal temperature and initial pH range for the production of pigment were 28
and 7.0-8.0, respectively. The red pigment was purified through solvent extraction and silica gel column chromatography. Analyzing the structure of this pigment by instrumental analysis, it was identified as prodigiosin-like compound. In optimization of carbon and nitrogen sources, all carbon sources tested in this work inhibited the production of pigment except oils. Casein fumed out to be the most suitable nitrogen source for pigment production. Other nitrogen sources such as yeast extract, beef extract and peptone showed good cell growth but potently inhibited the production of pigment.
The Hybrid Formation between Aspergillus oryzae var. oryzae and Penicillium chrysogenum by Nuclear Transfer and the Production of Alkaline Protease.
Microbiology and Biotechnology Letters, volume 26, issue 4, 1998, Pages 290~296
Interspecific hybrids between Aspergillus oryzae var. oryzae and Penicillium chrysogenum (Tyr
-/), high alkaline protease producing fungi, were obtained by nuclear transfer technique. Nuclei isolated from the wild type Aspergillus oryzae var. oryzae strain were transferred into auxotrophic Penicillium chrysogenum mutants and selected the new strains showing an increased protein degrading capability. Maximum production of protoplasts were obtained by 1% Novozym 234 at
for 3 hours and the most effective osmotic stabilizers for the isolation of protoplasts were 0.6M KCl. Frequencies of hybrid formation by nuclear transfer were 1.3
-3/. They could be suggested as an aneuploid by the observation of genetic stability, conidial size, DNA content, and nuclear strain. The hybrids showed 1.1～2.2 fold higher alkaline pretense activities than parental strains.
Purification and Characterization of
-Xylosidase B of Bacillus stearothemophilus No.236 Produced by Recombinant Escherichia coli.
Microbiology and Biotechnology Letters, volume 26, issue 4, 1998, Pages 297~302
-Xylosidase B was produced by Escherichia coli HB101/pKMG12 carrying the xylB gene of Bacillus stearothermophilus No.236 on its recombinant plasmid. The
-xylosidase B produced was purified by ammonium sulfate fractionation, DEAE-Sepharose CL-6B, Sephacryl S-200 and Superdex 200 HR gel filtration. The purified enzyme showed the highest activity at pH 6.5 and 5
. But, the enzyme was observed to be very sensitive to the pH and temperature of the reaction mixture. The enzyme was activated about 35% of its original activity in the presence of 1 mM of
but it was completely inhibited by
ions. In contrast with the
-xylosidase A, the B enzyme was found to have
-arabinofuranosidase activity though the activity was fairly low compared with the
-arabinofuranosidase produced from the arfI gene of the same Bacillus stearothermophilus. Therefore,
-xylosidase B is considered to be more suitable than
-xylosidase A at least for the biodegradation of arabinoxylan. The
values of the
-xylosidase B for o-nitrophenyl-
-D-xylopyranoside were 6.43 mM and 1.45
mole/min, respectively. Molecular mass of the enzyme was determind to be about 54 kDa by SDS-PAGE and 160 kDa by Superdex 200HR gel filtration, indicating that the functional
-xylosidase B was composed of three identical subunits.s.
Isolation and Characterization of Denitrifying Phenol-Degrading Bacterium Pseudomonas sp. HL100.
Microbiology and Biotechnology Letters, volume 26, issue 4, 1998, Pages 303~308
A bacterial strain which utilizes phenol under denitrifying condition was isolated from the industrial waste water collected from the Chong-ju Industrial Complex. The strain was identified as Pseudomonas species from the morphological, physiological, and biochemical characteristics and designated as HL100. The strain can utilize phenol as the sole source of carbon and energy when nitrate is provided as the terminal electron acceptor. The isolated strain completely degraded 3 mM of phenol within 110 hour with concomitant reduction of nitrate to nitrite. The observed maximum doubling time was 20 hours. Under appropriate condition, complete reduction of nitrate to atmospheric N
was observed indicating that the isolated strain could perform complete steps of denitrification. The strain showed optimal growth at pH 7.0 and temperature of 37
under denitrifying phenol-degrading condition. The strain can also utilize toluene as the sole carbon and energy source under the same growth condition. However, no growth was detected on xylene and benzene.
Purification and Characterization of an Extracellular Levansucrase from Zymomonas mobilis ZM1(ATCC 10988).
Microbiology and Biotechnology Letters, volume 26, issue 4, 1998, Pages 309~315
An extracellular levansucrase, which catalyzes the formation of levan from sucrose, from the culture broth of Zymomonas mobilis ZM1 was purified by conventional column purification methods. The final purification yield was 18.3 fold of the crude enzyme from Z. mobilis, with 16.5 % of the enzyme recovered in the preparation step. The molecular weight of the enzyme was estimated to be 91,000 by Superose 12 gel filtration, and 45,000 by SDS-PAGE, indicating that levansucrase is a dimer. The optimum pH for the enzyme activity was around pH 4.0 for sucrose hydrolysis, and was around pH 5.0 for levan formation. The enzyme was inhibited by some metal ions, such as Hg
2+/ and Cu2
2+/, and 50% of inhibition was observed with 5mM EDTA. The enzyme activity was enhanced by the presence of detergent Triton X-100, but inhibited by SDS completely The enzyme catalyzes the liberation of reducing sugars, oligosacccharides and the formation of fructose polymer(levan). The enzyme also catalyzes the transfructosylation reaction of fructose moiety from sucrose to various sugar acceptor molecules, including sugar alcohols.
Purification and Properties of Sunflower Seed
-Galactosidase by Affinity Chromatography.
Microbiology and Biotechnology Letters, volume 26, issue 4, 1998, Pages 316~322
-D-galactoside galactohydrolase, EC 3. 2. 1. 22) from sunflower seed was purified by affinity chromatography using N-
-D-galactopyranosylamine coupled to sepharose and its properties were examined. The specific activity of the purified enzyme, tested with p-nitrophenyl-
-D-galactopyranoside as substrate, was 291.66 units/mg protein, representing an 115-folds purification of the original crude extract. The final preparation obtained from by Sephadex G-25 chromatography showed a single band on SDS-polyacrylamide gel electrophoresis. The molecular weight was determined to be 42,000 by SDS-polyacrylamide gel electrophoresis. The purified galactosidase showed maximum activity at pH 4.5 and 55
, and was stable in the pH and temperature ranges of 4.0 to 5.0 and 30 to 55
, respectively. The enzyme activity was inhibited by Ag
2+/ and Co
2+/. The enzyme activity was not affected considerably by treatment with other metal compounds. The enzyme liberated galactose from melibiose, raffinose, copra galactomannan, guar gum and locust bean gum by TLC, and also the hydrolysis rate of substrate was compared by HPLC.
Purification and Characterization of
-Cyclodextrin Glucanotransferase Excreted by Bacillus firmus var. aikalophilus.
Microbiology and Biotechnology Letters, volume 26, issue 4, 1998, Pages 323~330
Cyclodextrin glucanotransferase (CGTase) was purified from the culture broth of the Bacillus firmus var. alkalophilus, using ultrafiltration, starch adsorption/desorption, ion-exchange chromatography on DEAE-cellulose and gel filtration on Sephacryl HR-100. The molecular weight of the purified enzyme was determined as 77,000 by SDS-PAGE. The optimum pH and temperature for the CD synthesis were 6.0 and 5
, respectively. The activity of this enzyme was stably kept at the range of pH 6.0～9.5 and up to 5
. However, in the presence of
, the optimum temperature for CD synthesis was shifted 55~6
and this enzyme was stable up to 6
because of the stabilizing effect of
. The purified CGTase produced CDs with high conversion yields of 45~51% from sweet potato starch, com starch and amylopectin as substrate, especially, and the product ratio of
-CD was obtained at range of from 5.8:1 to 8.4:1 according to the kind of substrate. The purified enzyme produced mainly
-CD without accumulation of
-CD during enzyme reaction using various starches as the substrate, indicating that the purified enzyme is the typical
-CGTase. The purified CGTase produced 25 g/l of CDs from 5.0% (w/v) liquefied com starch and the conversion yield of CDs was 50%, and the content of
-CD was 84% of total CDs after 8 hours under the optimum reaction condition.ion.
Studies on Screening and Comparison of Biological Activities fvom the Fruiting Body and Mycelium of Elfvingia applanata.
Microbiology and Biotechnology Letters, volume 26, issue 4, 1998, Pages 331~337
The biological activities of both ethanol and water extracts from the fruiting body of E. applanata and E. applanata mycelium and the three fractions of ethanol extracts from E. applanata were compared. 91% of MCF7 cell growth was inhibited by adding 0.5 g/l of water extracts of E. applanata and 81% of MCF7 cell growth was inhibited by adding 0.5 g/l of diethyl ether and chloroform fractions. It was also showed that above 60% of Hep3B cell growth was inhibited by adding all samples including the fractions. The ethanol extracts of E. applanata mycelium showed 33.3% of cytotoxicity on normal liver cell, WRL68 in adding 0.5 g/l of the samples and 40% in adding 0.5 g/l of chloroform fractions. The result of anti-mutagenicity of all extracts and fractions including ethanol extracts of Phelinus linteus were showed that diethyl ether fractions were most effective than any other samples. Hypoglycemic activities of diethyl ether and chloroform fractions were the most effective which scores were above 75%. The enhancement of glutathione-S-transferase activity was increased above 2.3 times by adding 1.0 g/l ethanol extracts of E. applanata and diethyl ether, chloroform fractions. It can be concluded that both biological activities of the fruiting body and mycelium of E. applanata were almost equivalent.
The Anti-Microbial Activity of Modified Chitosan.
Microbiology and Biotechnology Letters, volume 26, issue 4, 1998, Pages 338~344
New type of chitosan derivatives, chitosan-g-MAP, were synthesized by graft copolymerization of mono (2-methacryloyl oxyethyl) acid phosphate (MAP) into chitosan, in order to solubilize chitosan in water. Ceric ammonium nitrate was used as an initiator for graft copolymerization. The optimal conditions for graft copolymerization were determined on the basis of reaction temperature, time, and the concentration of initiator and monomer. The reaction conditions for the highest percentage of grafting were as follows: an initiator concentration, 3.5
-3/ M; monomer concentration, 0.19 M; and reaction temperature, 40
The reaction rate reached the maximum value after 4 hrs of reaction. Antifungal activity was tested against Candida albicans, Trichophyton rubrum and Trichophyton violaceum by using chitosan-g-MAP and two other chitosan samples which have degree of deacetylation of 70% (DA-7) and 90% (DA-90). Their antifungal activities were investigated in weak acidic range. Maximum antifungal activity of them was observed at pH 5.75. Chitosan-g-MAP inhibited thoroughly the growth of Candida albicans and Trichophyton violaceum. Howerver, DA-70 and DA-90 showed higher antifungal activities on Trichophyton rubrum than that of chitosan-g-MAP.
Endochitosanase Produced by Bacillus sp. P2l as a Potential Source for the Production of Chitooligosaccharides.
Microbiology and Biotechnology Letters, volume 26, issue 4, 1998, Pages 345~351
In an effort to develop a potent system for the production of various dp (degree of polymerization) chitooligosaccharides, 32 enzymes or microbial systems were screened for chitosanolytic acitivity using chitosan as a substrate. The efficiency of each enzyme system was evaluated by the changes of turbidity and viscosity of chitosan solution, the amount of precipitate and the reducing sugar-producing activity in the enzymatic reaction mixture. Based on these assay methods for the chitosanase activity, Bacillus sp. P2l out of 32 screened systems showed highly potent endochitosanase, which was comparable with a commercially available enzyme (E7). Chitooligosaccharides of dp 3-7 were separated by TLC as major enzymatic reaction products, suggesting that the chitosanase from Bacillus sp. P2l be endo-splitting type.
Biodegradation of Mixture of Benzoate and m-Toluate with Pseudomonas sp.
Microbiology and Biotechnology Letters, volume 26, issue 4, 1998, Pages 352~357
Biodegradation of benzoate and m-toluate was investigated using a Pseudomonas sp. isolated in a continuous culture for 45 days with a step-wise increase of the subsrates. The optimum mixture ratio of benzoate and m-toluate was 75% and 25%, respectively. During 45-day culture, removal of benzoate and m-toluate, which was replaced 2,000 ppm on the 30th day were 94% and 79%, respectively, when COD removal rate was 80%. The enzymatic activity of catechol 1,2-dioxygenase increased and that of catechol 2,3-dioxygenase decreased as the concentration of m-toluate was increased. These results suggested that m-toluate induced enzyme activity for degradation of benzoate. The shape of isolated strain in the continuous culture was investigated with SEM and the results showed that the cell shape was more damage according to the higher concentration of aromatic hydrocarbons. Therefore, we suggested that the tolerance against aromatic hydrocarbons was related to not only enzymatic activity but also characteristic of cell membrane or cell wall.
Formulation of a New Bacillus thuringiensis Strain NT0423.
Microbiology and Biotechnology Letters, volume 26, issue 4, 1998, Pages 358~364
New microbial-control agents were prepared with B. thuringiensis strain NT0423 having unique properties which are different with other B. thuringiensis strains belonging to serotype 7[Kor. J. Appl. Entomol. 32: 426-432.]. Three B. thuringiensis formulations designated as BioBact 10%, 20% and 40%, were made with various combinations of adjuvants. These formulations showed good physical properties in wettability, suspensibility, particle size and adherence. In addition the result of SDS-PAGE analysis indicated that
-endotoxins remain stably in all formulations. Among the tested formulations, two wettable powder formulations, BioBact 20% and 40%, comprising 20% and 40% of B. thuringiensis technical powder showed the effective control against diamondback moth larvae (Plutella xylostella) in laboratory and field tests. Especially, when compared with commercial B. thuringiensis formulations (A and B commercial formulations) in field evaluation, BioBact 20% and 40% formulations showed equal activity up to 80% lethality and a good persistence effect which remain on leaves at least 7 days.
Optimization of Refolding Conditions for the Aklavinone 11-Hydroxylase of Streptomyces peucetius Overexpressed in Escherichia coli.
Microbiology and Biotechnology Letters, volume 26, issue 4, 1998, Pages 365~368
The aklavinone 11-hydroxylase which was overexpressed using T7 promoter in E. coli could be detected in SDS-PAGE only in insoluble precipitate without any detectable enzyme activity. The insoluble enzyme was solubilized in 6M guanidine
HCl solution and their refolding ability was tested under various conditions. When the enzymatic activity was checked by the bioconversion experiment, stepwise dialysis against 6M, 3M, 1M guanidine
HCl and finally 100 mM potassium phosphate buffer of the solubilized protein gave the best bioconversion efficiency. The aklavinone 11-hydroxylase showed its enzymatic activity in the reaction buffer containing NADPH with vigorous shaking. The enzymatic activity was lost during partial purification and regained by the addition of crude extract of S. lividans in the reaction mixture. This effect was confirmed to due to some low-molecular weight component(s) in the crude extract, because the addition of dialyzed crude extract could not recover the enzymatic activity.
Formulations of Bacillus thuringiensis Insecticides by Liquid and Semi-Solid Fermentations.
Microbiology and Biotechnology Letters, volume 26, issue 4, 1998, Pages 369~372
Microbial insecticide formulations were prepared by liquid and semi-solid fermentations using Bacillus thuringiensis subsp. kurstaki, HL-106 (BTK-HL106), B. thuringiensis subsp. israelensis HL-63 (BTI-HL63) and B. sphaericus 1593 (BS-1593) strains. The liquid fermentation medium contained molasses 2%, dextrose 1.5%, peptone 2%, D-xylose 0.025%, CaCl
O 0.03%, FeSO
O 0.002%, ZnSO
O 0.02%. The composition of the semi-solid fermentation medium was rice bran 45.2%, zeolite 31%, yeast powder 0.02%, corn powder 5%, dextrose 3%, lime 0.3%, NaCl 0.06%, CaCl
0.02%, and H
O 15.42%. Insecticide formulations produced in the liquid fermentation named BTK-HL106, BTI-HL63 and BS-1593 pesticides and those in the semi-solid fermentation were designated as BTK-HL106-1, BTI-HL63-1 and BS-1593-1 pesticides, respectively. The number of spore (endotoxin crystals) was 2.65
9/ spores per
in the BTK-HL106 and 3.5
10/ in the BTK-HL106-1 3.8
9/ spores in the BTI-HL63 and 7.0
10/ in the BTI-HL63-1, and 7.5
9/ in the BS-1593 and 1.4
10/ in the BS-1593-1. The spores in the BS-1593 formulation was produced two times more than the other formulations. The spores in the BTI-HL63-1 were contained twice than those in the BTK-HL106-1, and five times than those in the BS-1593-1. The results indicated that spore (endotoxin crystals) productions in the semi-solid fermentation increased about ten times than those in the liquid fermentations.
s of the BTI-HL63 and BS-1593 were 4.5
, and those of the BTI-HL63-1 and BS-1593-1 were 1.5
of the BTK-HL106 was 1.5 mg and that of the BTK-HL106-1 was 0.9 mg. The
s of the formulations in the semi-solid fermentations showed about two to three times higher than those in the liquid fermentations.