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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
The Korean Journal of Microbiology
Journal Basic Information
Journal DOI :
The Microbiological Society of Korea
Editor in Chief :
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
Selecting the target year
A yeast Chromosomal Gene that Induces Defective Interfering Particles of L-A dsRNA Virus in
The Korean Journal of Microbiology, volume 29, issue 2, 1991, Pages 75~79
The yeast L-A virus (4.6 kb dsRNA genome) encodes the major coat protein and a "gag-pol" fusion minor coat protein that separately encapsidate itself and
, a 1.8 kb dsRNA satellite virus encoding a secreted protein toxin (the killer toxin). The teast chromosomal SKI genes prevent viral cytopathology by lowering the virus copy number. Thus,
mutants are ts and cs for growth. We transformed a ski2-2 virus-infested mutant with a yeast bank in a high copy cloning vector and selected the rare healthy transformants for analysis. One type of transformant segregated M-O L-A-O cells with high frequency. Elimination of the DNA clone from the ski2-2 strain eliminated this phinotype and introduction of the DNA clone recovered from such transformants into the parent ski2-2 strain, or into ski3 or ski6 mutants gave the same phenotype. This killer-curing phenotype was due to the curing of the helper L-A dsRNA virus. The 6.5 kb insert only had this activity when carried on a high copy vector and in
cells (not in
cells). This 6.5 kb insert acts as a mutagen on L-A dsRNA producing a high rate of deletion mutations.mutations.
Expression of Hepatitis B Viral Core Antigen Gene in Excherichia coli
The Korean Journal of Microbiology, volume 29, issue 2, 1991, Pages 80~84
We cloned and expressed hepatitis B viral core antigen (HBcAg) gene in E. coli using
promoter system. For optimal expression of the gene, we undertook the studies on the effects of the distance between Shine-Dalgarno (SD) sequence and start codon, copy number of repressor gene, induction temperature, and the stability of the core antigen. The results demonstrated that the induction at 37.deg.C was more efficient than at 42.deg.C, and the 11 base pairs (bp) distance between SD sequence and start codon of HBcAg gene was more efficient than the 15 bp distance in E. coli. The copy number of cI857 repressor gene did not influence on the expression of HBcAg, and the expression level of HBcAg in mutant type (low protease activity) and wild type strains was almost the same. The produced core antigen appeared to be HBcAg not HBeAg judged by two different radioimmunoassat (RIA) kits. This result suggested that the antigen was stable in E. coli.i.
-1,4-D-Glucan Glucanohydrolase Purified from Trichoderma koningii
The Korean Journal of Microbiology, volume 29, issue 2, 1991, Pages 85~91
.betha.-1,4-D-Glucan glucanohydrolase(EC 126.96.36.199;F-II-IV) purified from Trichoderma koningii was identified as a glycoprotein containing 9% carbohydrate. Isoelectric point of the enzyme was estimated to be 4.9 and molecular weight was determined to be approximately 58,000. The porducts of p-nitrophenyl-cellobioside (
) catalyzed by the enzyme were p-nitrophenol(PNP) and p-nitrophenyl-glucoside(
). The Km value for
was estimated to be 0.97 mM in case of the holoside lindage and 10.4 mM in case of the aglycon linkage and their kcat values were
respectively. The product of p-nitrophenyl cellotriose(
) was only
. The Km value for
was 69.5 .
M and kcat was
which implicates that the enzyme have higher affinity and higher hydrolysis rate toward
. The enzyme showed its optimal activity at pH 4.0-4.5 and at 60.deg.C. The effect of gluconolactone on the activity toward
showed competitive inhibition pattern but glucose and cellobiose did not. The enzyme contained a high content of acidic and hydroxylated amino acids in contrast to basic amino acids.
Purification of Cytochrome c-551 from Photosynthetic Bacterium Rhodopseudomonas Gelatinosa ATCC 17013
The Korean Journal of Microbiology, volume 29, issue 2, 1991, Pages 92~96
The soluble cytochrome c-551 of photosynthetic bacterium, Rhodopseudomonas gelatinosa ATCC 17013 was purified through a sequene of four step chromatography including CM-cellulose ion-exchange chromatography, DEAE-Sephacel chromatography, Sephacryl s-200 gel permeation chromatography, and HPLC (SP-5PW). The molecular weight of the purified cytochrome c-551 was 14, 600 Da, and this protein shows the absorption peak at 551 nm, 522 nm, and 417 nm as the reduced form, and at 412 nm as the oxidized form. The cytochrome c-551 seems to be a substrate for the terminal oxidase in the electron transport chain.
Purification and characterization of glutamine phosphoribosylpyrophosphate amidotransferase from streptomyces tubercidicus
The Korean Journal of Microbiology, volume 29, issue 2, 1991, Pages 97~103
Glutamine phosphoribosylpyrophosphate amidotransferase of Streptomyces tubercidicus was purified and characterized. Molecular weight of the isolated enzyme was determined to be approximately 230,000 and was composed foru identical subunits having a molecular weight of 58,000. This enzyme was strongly inhibited by AMP while considerably inhibited by ATP and GTP. Inhibition effect of enzyme activity by AMP was antagonized by increased concentration of substrate, PRPP, and metal ion (especially,
) was essential in both catalytic activity and nucleotide inhibition of this enzyme. Therefore, it was confirmed that end product inhibition of glutamine phosphoribosylpyrophosphate amidotransferase by adenine participated in the regulation of tubercidin biosynthesis from Streptomyces tubercidicus.s.
Purification and Properties of Glucoamylase from Schwanniomyces castellii
The Korean Journal of Microbiology, volume 29, issue 2, 1991, Pages 104~110
The glucoamylase of Schwanniomyces castellii was purified to homogeneity from the culture filtrate. the purified enzyme was a glycoprotein with a molecular mass of about 145 KDa, which was monomeric protein with an isoelectric point of 4.3. The pH and temperature optima were 5.5 and 40.deg.C, respectively. The enzyme was fairly stable up to 50.deg.C and at acid pH range (pH 4.5-6.0). The apparent Km of the enzyme toward soluble starch, isomaltose and pullulan were 3.84, 0.51 and 13.7 mg/ml, respectively. The analysis of amino acid composition on this enzyme was found to be acidic protein like other fungal glucoamylase. The amino acid sequence of N-terminal peptide consisted of Ala-Pro-Ala-Asp-Gly-Ile-Gly-Asp-X-Ala-X-Ala.
Transformation Pathway of the Progesterone by Rhizopus nigricans
The Korean Journal of Microbiology, volume 29, issue 2, 1991, Pages 111~116
Rhizopus nigricans produces 11.alpha.-hydroxyprogesternoe with a unidentified byproduct, which is hardly separated. Results of chromatography, IR and NMR spectroscopy identified the byproduct to be 11.alpha.-hydroxy-allopregnane-3,20-dione. R. nigricans was found to transform progesternoe into a monoform intermediate, 11.alpha.-hydroxyprogesterone, from which 11.alpha.-hydroxy-allopregnane-3,20-dione and 6.betha., 11.alpha. - dihydroxyprogesterone were formed respectively by 5.alpha.-reduction and 6.betha.-hydroxylation.
Improvement of bacteria for removing of phosphate by spheroplast fusion
The Korean Journal of Microbiology, volume 29, issue 2, 1991, Pages 117~122
In order to improve the removal ability of phosphate, Spheroplast fusions were performed among auxotrophic mutants of Aeromonas hydrophila isolated from waste water, named A13 and A14, Aci37 auxotrophic mutant of Acinetobactercalcoaceticus, and auxotrophic E. coli HR262/pCE27 carring pit gene. Eight fusants obtained from this experiment showed different biochemical characteristics. When the rate of phosphate uptake among fusants (F1-F8) was investigated in Phosphate Uptake Medium (PUM), F8 strain showed the highest rate for phosphate removal, 7 times as much as control after two hours incubation. The role of cations (
in phosphate uptade by F8 was also investigated in PUM without each salt.
seemed to be crucial. Being compared with phosphate untake rate in PUM, that in PUM without
was reduced 1.5 times. Therefore, by applying F8 strain and
in practical environmental system, the increased efficiency in phosphate removal can be derived.
Interspecific Protoplast Fusion between Fusarium poae and Fusarium sporotrichioides
The Korean Journal of Microbiology, volume 29, issue 2, 1991, Pages 123~129
In order to develop the protoplast fusion method of the strains of Fusarium, the interspecific protoplast fusion was attempted between Fusarium poae and F. sporotrichioides. Various auxotrophic mutants were isolated by the treatment of N-Methyl-N'-Nitro-N-Nitrosoguanidine. The optimal conditions for the formation and regeneration of protoplasts were examined and the characteristics of a fusant were studied. As a results, protoplasts were readily obtained from 18 hours cultured mycelia by the treatment of driselase for 3 hours and 0.6 M KCl as a best osmotic stabilizer at pH 6.0 for the formation of protoplast. Sucrose was the most suitable for the regeneration. Polyetylene glycol (M.W. 8,000) in
-glycine solution was used to induce the protoplast fusion. The interspecific fusion frequency between protoplasts among the auxotrophic mutants of the two strains ranged from
. DNA content and cellulase activity were rather increased in the interspecific fusant. The lag phase of growth curve was slightly elongated in the fusant.
Effects of Butachlor on the Growth of PurpleNnon-sulfur Bacteria
The Korean Journal of Microbiology, volume 29, issue 2, 1991, Pages 130~135
The effects of a herbicide butachlor[2-chloro-2', 6'-diethyl-N-(butoxymethyl) acetanilide] on the growth of the purple non-sulfur bacteria were investigated. The butachlor inhibited the growth of all species tested by 18-51%, except Rhodospirillum rubrum at concentrations of M, which would be field capacity. The photosynthetic growth rate of the species in the presence of butachlor was influenced by the nitrogen source. Cultures supplied with (NH&S04 showed a somewhat higher growth rate than those fixing dinitrogen, but they were more susceptible to butachlor (26-51%). On the contrary, butachlor enhanced the growth rate of Rhodospirillum rubrum in nitrogen gas conditions. When the culture was performed in medium with butachlor as the carbon source, the cells of fixing dinitrogen showed a higher exhaustion of butachlor than those supplemented with (N&)2S04, which exhaustion was examined by a decrease of the major absorbance at 213 nm and 260 nm. The exhaustion of butachlor as the carbon source had relation with the growth of the cells. The alkalization of culture supplemented with nitrogen gas was found in the cells treated with butachlor or untreated. The butachlor affected the carotenoid region but bacteriochlorophyll remained unaffected.
Isolation of Ethanol-tolerant Strains of Yeast in Relation to Their Tolerant Mechanism
The Korean Journal of Microbiology, volume 29, issue 2, 1991, Pages 136~142
The selection of ethanol-tolerant strains was applied to enrichment culture of YPD broth medium containing various concentrations of ethanol. Isolates were identified to be Saccharomyces cerevisiae, the others as S. dairensis, S. exiguus, S. telluris, Saccharomycodes ludwigii, Schwanniomyces occidentalis var. occidentalis and Zygosaccharomyces florentinus. Among isolates S. cerevisiae YO-1 was screened as having the highest ethanol tolerance and produced 18% (v/v) ethanol after 4 days fermentation. The change of fatty-acyl residues represents that a progressive decrease in fatty-acyl unsaturation and a proportional increase in saturation in phospholipids of yeast cells during fermentation affected the yeast viability. Supplementation ethanol to the cultures led to an increase of unsaturated fatty-acyl residues, especially
residues, along with a decrease in the proportion of saturated residues in cellular phospholipids. Increasing the amount of soy flour led to an increase in the maximum number of viable yeast cells and ethanol production. It was possible in 4 days to reach 21% (v/v) ethanol by adding 4% soy flour as source of unsaturated fatty-acyl residues to the fermentation medium. Soy flour not only increased yeast population but also enhanced the physiological properties of yeast cells to be ethanol tolerant in the anaerobic culture.
Characteristics of Bradyrhizobium japonicum SNU001, aSsymbiotic Strain of Glycion max
The Korean Journal of Microbiology, volume 29, issue 2, 1991, Pages 143~147
The root nodules and Glycine max were classified as determinate nodule based on their morphological characteristics, and isolated endosymbiont as a Bradyrhizobium based on its growth rate and single subpolar flagellum. The isolate was similar to B. japonicum USDA110 in utilization of carbon source, growth at 38.deg.C and 2% NaCl, production of
S and especially in the restriction endonuclease digestion pattern of symbiotic genes, allowing them to be placed in sTI group together. The former, however, grew better than the later in broad pH range from 5.0 to 9.5. Infectivity and effectivity of the isolate were confirmed by inoculation of soybean seedlings with the isolates. Characteristics of the reisolated endosymbiont from induced root nodules were identical to those of the first isolate. From these results, it was confirmed that Bradyrhizobium strain isolated from the root nodules of Glycine max was a real symbiont, and was named B. japonicum SNU001.