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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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The Korean Journal of Microbiology
Journal Basic Information
Journal DOI :
The Microbiological Society of Korea
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Volume & Issues
Volume 29, Issue 6 - Dec 1991
Volume 29, Issue 5 - Nov 1991
Volume 29, Issue 4 - Sep 1991
Volume 29, Issue 3 - Jul 1991
Volume 29, Issue 2 - May 1991
Volume 29, Issue 1 - Mar 1991
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Molecular Cloning and Expression of dapA, the Gene for Dihydrodipicolinate Synthetase of Corynebacterium glutamicum
The Korean Journal of Microbiology, volume 29, issue 4, 1991, Pages 203~208
The dapA-complementing gene (L-2, 3-dihydrodipicolinate synthetase: DHDP synthetase, dapA) has been cloned by using a cosmid genomic bank of Corynebacterium glutamicum JS231 that is a lysine overproducer, AEC (s-(2-aminoethyl)-L-cysteine) resistant mutant. By enzymatic deletion analysis, the DNA region complementing the escherichia coli dapA host could be confined to 4.5kb SalI-generated DNA fragment. This DNA fragment was inserted into the C. glutamicum/E. coli shuttle vector pECCG117 to construct pDHDP5812. The specific activity of DHDP synthetase detected in C. glutamicum JS231/pDHDP5812 was increased about 10 fold above that of C. glutamicum JS231. The addition of leucine during growth did not repress the expressin of dapA, and the enzyme activity was not inhibited by lysine.
Determination of Active Site in PRD1 DNA Polymerase by Site-specific Mutagenesis
The Korean Journal of Microbiology, volume 29, issue 4, 1991, Pages 209~214
The PRD1 DNA polymerase is a small multi-functional enzyme containing conserved amino acid sequences shared by family B DNA polymerases. Thus the PRD1 DNA polymerase provides an useful model system with which to study structure-functional relationships of DNA polymerase molecules. In order to investigate the functional and structural roles of the highly conserved amino acid sequences, we have introduced three mutations into a conserved amino acid of the PRD1 DNA polymerase. Genetic complememtation study indicated that each mutation inactivated DNA polymerase catalytic activity.
Osmotic-inducible Gene Expression using MudJ(Km.lac) Operon Fusion in Salmonella typhimurium
The Korean Journal of Microbiology, volume 29, issue 4, 1991, Pages 215~220
MudJ(Km.lac) operon fusions were used in the identification of osmotic-inducible genetic(osi) loci in Salmonella typhimurium. Expression of osi::lacZ(osi5001, 5027) genes were dramatically induced 39-189 fold when the osmolarity was increased. Seven osm::lacZ genes were constituvely expressed under both low and high osmotic strength. The osi5001::lacZ fusion strains showed the enhanced osmotolerance and the reduced expression of the osi5001::lacZ in the presence of 1mM proline or betaine as osmoprotectants. Four osmotic inducible genetic loci were mapped into 36 (YK531), 44 (YK504), 57 (YK501) and 84 (YK528) map unit by testing the cotransduction frequency.
Analysis of RNA Transcripts Generated by Bluetongue Virus core
;Manning, JaRue S.;
The Korean Journal of Microbiology, volume 29, issue 4, 1991, Pages 221~225
The RNA transcripts produced from in vitro transcription reaction of BTV core were analyzed on agarose-urea gel. Fast migrating abortive RNAs, in addition to full length species of RNA, were observed. Fast migrating RNAs extracted from agarose-urea gel were hybridized to all 10 segments of genomic ds RNA, while solw migrating RNAs extracted from agarose-urea gel were hybridized only to the large and medium size genomic ds RNA. These results indicate that fast migrating RNA transcripts are most likely the products of abortive transcription.
Restriction Map of the R Plasmid pKU10 in Pseudomonas putida
The Korean Journal of Microbiology, volume 29, issue 4, 1991, Pages 226~229
In our laboratory a R plasmid pKU10 was isolated from Pseudomonas and its characteristics were investigated. In this study, as a basic work to improve its utility as a cloning vehicle, restriction patterns of pKU10 were analyzed for other various restriction enzymes in addition to restriction evdonucleases previously examined. As a result, pKU10 DNA has two cleavage sites for ClaI and HpaI, and three sites for AvaI. The restriction map of pKU10 was supplemented with AvaI, ClaI, and HpaI. From the result of this experiment, the usefulness of PKU10 as a cloning vector in Pseudomonas will be enhanced by constructions of mini-plasmid or hybrid plasmids.
Purification and Characterization of Nonmitochondrial Citrate Synthase from Saccharomyces cerevisiae
The Korean Journal of Microbiology, volume 29, issue 4, 1991, Pages 230~237
Citrate synthase 1 (mitochondrial) and citrate synthase 2 (nonmitochondrial) were purified from Saccharomyces cerevisiae. The physical and enzymatic characteristics of citrate synthase 2 were ananlyzed in comparison with citrate synthase 1. Both isoenzymes were shown to be dimeric proteins of identical subunits, and the molecular weights of the subunits were estimated to be 48.3kDa for citrate synthase 1 and 47.0kDa for citrate synthase 2, respectively. The optimal pH value for enzyme activity was pH 7.5 for both isoenzymes. However, the optimal temperature for the activity was strikingly different; while the activity of citrate synthase 1 reached its peak at 65.deg.C, that of citrate synthase 2 was maximal at 40.deg.C. Citrate synthase 2 showed much lower thermal and pH stability than citrate synthase 1. In addition, citrate synthase 2 was affected much more by the metal ions such as
than citrate synthase 1. Among the several possible regulatory metabolites tested, ATP showed the strongest inhibitory effect on both enzymes. ADP and NADH were found to have greater effect on citrate synthase 2 than on citrate synthase 1. Kinetic analysis revealed that citrate synthase 2 has approximately 7- and 3.5-fold lower affinity to acetyl CoA and to oxaloacetate, respectively, than citrate synthase 1.
Estimation of the Prosthetic Group of Laccase Secreted from Pleurotus ostreatus
The Korean Journal of Microbiology, volume 29, issue 4, 1991, Pages 238~242
Extracellular laccase secreted from Pleurotus ostreatus was activated by
. The enzyme was strongly inactivated by 8-hydroxyquinoline, potassium cyanide, sodium azide, sodium bisulfite and 2-mercaptoethanol. The two ionogenic groups, which have pKa values of 5.60-5.70 and 6.70-6.85 respectively, were found to relate with the active site of this enzyme. The oxidation reactions were brought about by initial single electron transfer process on the active site. The enzyme was found to be a metalloprotein which had about 3.9 cupric ions per molecule of protein as a prosthetic group. The enzyme showed a strong peak at 605 nm and a weak shoulder at 330 nm in UV-Visible absorption spectrum. Both signals disappeated upon treatment of the enzyme with 4 electron equivalent ascorbate. These results indicate that type I Cu peak and type III Cu shoulder are present in laccase.
Identification and characterization of cytochrome
complex and cytochrome c oxidase in chromatophore of rhodopseudomonas gelatinosa
The Korean Journal of Microbiology, volume 29, issue 4, 1991, Pages 243~249
The chromatophore from the chemotrophically grown facultative anaerobic photosynthetic bacterium, Rhodopseudomonas gelatinosa ATCC 17013 was isolated through stepwise sucrose gradient centrifugation. The isolated chromatophore showed high activities of the cytochrome
complex and cytochrome c oxidase. The activity of cytochrome
complex was completely inhibited by .
M antimycin A,
M myxothiazol, and that of cytochrome c oxidase was completely inhibited by .
M KCM and
but not inhibited by carbon monoxie. The activity of cytochrome c oxidase of th chromatophore was increased by addition of ionophores or protonophores. The reduced-oxidised difference sspectrum of cytochrome
complex isolated by affivity chromatography showed the absorption maxima at 553 nm(shoulder at 547 nm), 520 nm, and 418.5 nm, on the other hand, that of cytochrome c oxidase showed .alpha., .betha. and soret peaks at 554 nm, 523 nm, and 421 nm, respectively. The cytochrome c oxidase from chemotrophically grown Rhodopseudomonas gelatinosa seems to be a b-type cytochrome c oxidase.
A Methylobacillus Isolate Growing Only on Methanol
The Korean Journal of Microbiology, volume 29, issue 4, 1991, Pages 250~257
An obligate methanol-oxidizing bacterium, Methylobacillus sp. strain SK1, which grows only on methanol was isolated from soil. The isolate was nonmotile Gram-negtive rod. It does not have internal membrane system. The colonies were small, whitish-yellow, and smooth. The guanine plus cytosine content of the DNA was 48 mol%. Cellular fatty acids consisted predominantly of large amounts of straight-chain saturated
acid and unsaturated
acid. The major ubiquinone was Q-8, and Q-10 was present as minor component. The cell was obligately aerobic and exhibited catalase, but no oxidase, activity. Poly-.betha.-hydroxybutyrate, endospores, or cysts were not observed. the isolate could grow only on methanol in mineral medium. Growth factors were not required. The isolate was unable to use methane, formaldehyde, formate, methylamine, and several other organic compounds tested as a sole source of carbon and energy. Growth was optimal at 35.deg.C and pH 7.5. It could not grow at 42.deg.C. The doubling time was 1.2h at 30.deg.C when grown with 1.0%(v/v) methanol. The growth was not affected by antibiotics inhibiting cell wall synthesis and carbon monoxide but was completely suppressed by those inhibiting protein synthesis. Methanol was found to be assimilated through the ribulose monophosphate pathway. Cytochromes of b-, c-, and o- types were found. Cell-free extracts contained a phenazine methosulfate-linked methanol dehydrogenase activity, which required ammonium ions as an activator. Cells harvested after the late exponential phase seemed to contain blue protein.ein.
Effects of Glucose on the Products of Progesterone Transformation by Rhizopus nigricans
The Korean Journal of Microbiology, volume 29, issue 4, 1991, Pages 258~262
Rate of 11.alpha.-hydroxylation of progesterone with Rhizopus nigricans was accelerated by glucose. Glucose seemed to play an important role in the formation of cofactor because its effects on the reaction were almost same as those of electron acceptors such as NADPH and
. Rate of glucose consumption appeared to increase in proportion as the rate of hydroxylation reaction, which enhanced with increase in the glucose concentration to level off at 0.5 g/l for mycelia and at 20 g/l for spores. However, for mycelia immobilized in polyacrylamide gel, externally added glucose did not affect the reaction rate at all because of the glucose accumulated in the gel during the cultivation period. 5.alpha.-Reduction of 11.alpha.-hydroxyprogesternoe required much higher concentration of glucose than 11.alpha.-hydroxylation of progesternoe so that high yield of 11.alpha.-hydroxyprogesternoe can be obtained by repressing the activity of 5.alpha.-reductase at low concentration of glucose.
Growth and Physiology of Thiobacillus novellus under Autotrophic and Heterotrophic Conditions
The Korean Journal of Microbiology, volume 29, issue 4, 1991, Pages 263~266
The growth of T. novellus in auto trophic and geterotrophic media was studied to determine the time required for cells to enter stationary phase and relative percentage of ribosomal proteins. When T. novellus was grown autotrophically, growth proceeded at a slow rate characteristic of autotrophs and did not enter log phase until the end of the first day. Logarithmic growth proceeded for 3-4 days at which time the cells entered the stationary phase. In particular, logarithmic growth was accompanied by decreasing pH of culture media and in the stationary phase the pH levelled off at 6.0, a decrease of 1.6 pH value compared to original pH of media. The pH decrease was greatest during log phase when cells oxidized thiosulfate to
. The doubling time was about 26h. In heterotrophic media growth proceeded at a much faster rate and cells entered stationary phase 20-22h after inoculation. The doubling time was 3h. The protein content of the ribosomes in T. novellus grown heterotrophically was 4.2% greater than those from the organism grown autotrophically.