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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Microbiology and Biotechnology Letters
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Journal DOI :
The Korean Society for Applied Microbiology and Biotechnology
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Volume & Issues
Volume 12, Issue 4 - Dec 1984
Volume 12, Issue 3 - 00 1984
Volume 12, Issue 2 - 00 1984
Volume 12, Issue 1 - 00 1984
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In-Vifvo and In-Vitro Stability of DAHP Synthase from E. coli - Isolation of a tyr R mutant -
Choi, Yong-Jin ; Park, Young-Sook ;
Microbiology and Biotechnology Letters, volume 12, issue 2, 1984, Pages 65~65
The aim of this study was to isolate a mutant strain of Escherichia coli in which the DAHP synthase(phe) isoenzyme was highly elevated. This isoenzyme was reported to be more stable than the DAHP synthase(tyr) isoenzyme, another major isoemzyme presented in E. coli, during stationary phase of cell growth, and then to have greater effects on aromatic amino acid formation. The mutant was obtained from a parent strain possessing only a single DAHP synthase isoenzyme, desensitized DAHP synthase(phe)by selecting for resistance to the tyrosine analogue, 3-fluorotyrosine. A series of experiments on the analogue resistance of the starting strain showed that 3-fluorotyrosine could be the most powerful analogue for obtaining the desired mutation. The increase in level of DAHP synthase(phe) activty in the mutant was about fivefold even in the presence of the aromatic amino acids, and the mutation responsible for this derepression has been mapped closed to previously reported tyrR mutations by showing a cotransduction frequency of about 20% with pyrF marker. The data from the biochemical and genetic analyses gave a confirmation that the mutatin freshly obatined in this study was linked to the tyrR gene locus.
Precipitation of Milk Proteins in Fermented Milk Beverage
Kang, Kook-Hee ; Lee, Chul-Nam ;
Microbiology and Biotechnology Letters, volume 12, issue 2, 1984, Pages 73~73
Factors supposed to be involved in the abnormal precipitation of fermented milk beverage were analyzed. The main component of the precipitated mass was to be casein. The moderate heat treatment of the reconstituted skim milk before the fementation did not affect on both starter growth and protein precipitation. Homogenization of the milk up to 200kg/
did not prevent the precipitation problem. Kinds of starter organisms used showed some effect and the use of Lactobacillus casei was disirable. Prolonged feremntation with L. casei could reduce the precipitation and no precipitation was observed when the fermentation continued for more than 48 hours.
Xylanase produced by Thermophilic Alkalophilic Bacteria - Isolation and Some Properties of Bacillus spp. -
Sung, Nack-Kie ; Kang, In-Soo ; Chun, Hyo-Kon ; Teruhiko, Akiba ; Horikoshi, Koki ;
Microbiology and Biotechnology Letters, volume 12, issue 2, 1984, Pages 81~81
Of the bacterial strains which were isolated from soils by incubating in the xylan-containing medium at pH 10.3 and
, 5 strains were selected and their bacterial characteristics were examined. Their characteristics were almost consistent with those of the genus Bacillus. The optimal temperature of growth, specific growth rate and doubling time was in the range of
, and their growth was also good at
. The optimal temperature of enzyme production was agreed with that of bacterial growth. The crude enzyme was stable at
, but the enzyme activity was greatly lost by heating at
for 10 minutes. The optimal pH rnage of growth and enzyme production was 9-10, and no growth was observed at pH 7.0, indicating that they were alkalophilic bacteria. The hydrolysis products from xylan by crude enzyme, analyzed by TLC, were xylose and xylobiose.
Biodegradation of Synthetic Detergents by Klebsiella pneumoniae L-127
Hong, Soon-Duck ; Lee, Sang-Han ; Hah, Sang-Chul ; Ha, Hyeon-Pal ;
Microbiology and Biotechnology Letters, volume 12, issue 2, 1984, Pages 91~91
A bacterium which degrades efficiently synthetic detergents was isolated from the sewage of Taegu area. Cultivation of the bacterium in the medium containing 0.1% linear alkylate sulfonate (LAS) increased its growth by 2%. At a concentration of 2% linear alkylate sulfonate, the growth of the strain was inhibited by 39%. This strain degraded 93% of linear alkylate sulfonate, 47% of sodium dodecylbenzene sulfonate(SDBS), and 35% of sodium dioctylsulfosuccinate(SDSS) when cultured in a medium containing one of the detergents at a concentration of 0.1%. Cell growth of the bacterium was markedly inhibited by 0.2mM of
and by 20ppm of kanamycin. The L-127 was identified as a similar strain to Klebsiella pneumoniae on its morphological, cultural and physiological characteristics.
Strain Development of Zymomonas mobilis for Ethanol Production - Optimal conditions for the spheroplast formation and regeneration -
Lee, Kye-Joon ; Seong, Chi-Nam ;
Microbiology and Biotechnology Letters, volume 12, issue 2, 1984, Pages 99~99
Optimal conditions for the formation of spheroplasts of Zymononas mobilis and the regneration from the spheroplasts were evaluated. It was observed that young cells of Z.mobilis could readily converted to spherical cells with treatment of glycine. D-sorbitol could be used for an alternative osmotic stabilizer in spheroplast formation. Regeneration of spheroplasts was improved when the regeneration rich medium was supplemented with Magnesium salts and 0.1% casaminoacid. Embedded incubation in the 1.0% soft agar was most effective. Under these conditions salts and 0.1% casaminoacid. Embedded incubation in the 1.0% soft agar was most effective. Under these conditions regeneration frequency was about 1.5%.
Destructive Action of Ozone on the Capsid and DNA of Bacteriophage T4
Kim, Chi-Kyung ; Kim, Chang-Han ; Mheen, Tae-Ick ;
Microbiology and Biotechnology Letters, volume 12, issue 2, 1984, Pages 105~105
The destructive action of ozone was investigated with bacteriophage T4 under controlled laboratory conditions. The inactivation kinetics of the phage and its DNA were studied, and the protein capsid and DNA ozonated were examined by electron microscopies. Ozone appeared to attack the capsid proteins of the phage, randomly destroying the head, collar, contractile sheath, end plate and tail fibers, and liberating the DNA from the head. The naked DAN was sheared by ozonation and lost its infectivity in the same pattern as the inactivation of the intact phage.
Properties and Functions of Intracellular Acid Protease II in Rhodotorula glutinis
Lee, Tae-Ho ;
Microbiology and Biotechnology Letters, volume 12, issue 2, 1984, Pages 111~111
Acid protease II found in the insoluble partical fraction of Rhodotorula glutinis K-24 cells was extracted by treating the fraction with a detergent, Triton X-100. The enzyme is believed to play important roles for the physiological functions of the cell such as in-vivo turn over of protein and activation or inactivation of various enzymes. Acid protease II, one of the two kinds of intracellular acid proteases inhibited by pepsin inhibitor(S-PI) was purified from homogenate of Rh. glutinis by extraction with Triton X-100, chromatography on DEAE-Sephadex A-50, and SP-Sephadex C-50. Sodium dodecyl sulfate polyacrylamide gel electrophoresis of the purified enzyme gave a single band. The molecular weight was estimated to be 42,000 by SDS disc electrophoresis. The
at 280nm and isoelectric point of the purified enzyme were determined to be 12.4 and pH 4.5 respectively. The optimum pH for hydrolysis of casein was approximately 5.5 under the experimental conditions. It lost no activity at all for 1 hr at
in the pH range of 3.0-6.0. The enzyme was strongly inhibited by diazoacetyl norleucine methyl ester(DAN), pepsin inhibitor(S-PI), and sodium lauryl sulfate(SLS).
Increase of Ultraviolet Resistance by Acquisition of Plasmids in Bacteria
Cho, Bong-Gum ;
Microbiology and Biotechnology Letters, volume 12, issue 2, 1984, Pages 119~119
This study was carried out to examine the change of ultraviolet resistance of bacterial strains by acquiring a plasmid such as a drug resistance transfer factor R2, a degradative plasmid TOL(toluene) and a colicin producing factor Col El. With Ps. aeruginosa ultraviolet resistance was increased with the shoulder Dq=2.8 and gradient slope
=1.8 of the U.V.irradiation survival curve of the organisms by acquiring drug resistant factor
. Similar results were observed with drug resistant plasmid
and also with
plasmid. On the other hand, some bacterial strains become more sensitive to U.V. light by acquiring a plasmid. In Ps. putida the cells grown on 0.1% benzoate medium showed higher U.V. resistance than the cells grown on glucose medium. Tol factor was found to endow the host organisms grown on either of the above media with strong V.V. resistance. These results suggest that the degradative plasmid itself may have the genetic information responsible for the host cell's ability to resist to U.V. irradiation.
Changes of Component in Sikhei during Saccharification
Kim, Bok-Sun ; Lee, Taik-Soo ; Lee, Myung-Whan ;
Microbiology and Biotechnology Letters, volume 12, issue 2, 1984, Pages 125~125
In order to improve the quality of Sikhei, the Korean conventional rice beverage, koji instead of malt or the mixture of koji and malt as a saccharifying agent was used to prepare Sikhei. The changes of chemical components and enzyme activities during saccharification were investigated. The total sugar and reducing sugar during saccharification were increased gradually. The Sikhei saaccharified for 8 hours showed total sugar of 17.8-18.38% and reducing sugar of 8.91-14.97% and those contents were higher in the order of koji addition group, mixed group, and malt addition group. The pH was measured to be 5.60-5.75 for malt addition group, 6.10-6.45 for koji addition group and 6.00-6.15 for mixed group. Titrable acidity was higher inthe order of malt addition group, mixed group and koji addition group. Koji addition group was highest in the specific gravity with a range of 1.012 to 1.062. Saccharogenic amylase activity of koji addition group was higher than that of the mixed group and the malt addition in the early stage of saccharification, while that of the mixed group showed higher in the end stage of saccharification.
Effect of Biochemical Factors on the Bacterial Spore Membrane for Bacillus subtilis SNU.816
Lee, Zoo-Shik ; Kang, Chul-Hee ; Lee, Oh-Byoung ; Byon, Sang-Suk ;
Microbiology and Biotechnology Letters, volume 12, issue 2, 1984, Pages 131~131
Bacillus subtilis SNU816 is used in soy bean fermentation in Korea, and is a flavoring agent. The spores of this strain showed relatively higher heat resistance than those of other bacilli strains. Two purified enzyme, glucose dehydrogenase and L-alanine dehydrogenase isolated from both vegetative cells and spores, showed no notable difference in heat resistance and in other properties. These enzymes were inactivated rapidly between 40 and
. These results implicated that the heat resistant spores might not contain any heat stable enzyme. Furthermore, Theresistance of spore to heat was severely decreased when the coat layer of spore was destructed by treating various thiol compounds. And the decrease of heat resistance caused by above treatment could be overcome by increasing the concentration of environmental sucrose. All of these results led us to consider that the resistance of spore to heat might be rendered by spore structure itself rather than by properties of core of spore. Several other results supporting the expanded cortex hypothesis were described and discussed briefly in report.
-Amylase Secretion in Teichoic acid Defective Coditions on Bacillus amyloliquefaciens
Song, Bang-Ho ; Lee, Nan-Sook ;
Microbiology and Biotechnology Letters, volume 12, issue 2, 1984, Pages 139~139
Extracellular secretion of the enzyme amylase was studied in B.amyloliquefaciens and B.subtilis by comparing the secretion of this enzyme in cells where peptidoglycan synthesis had been inhibited by tunicamycin treatment with that of normal wild type cells. One of the substances which decreased in tunicamycin treated cells was identified as a teichoic acid. Because of the striking correspondence between the decrease of the above teichoic acid and the accumulation of cell-bound
-amylase, this teichoic acid was thought to play an important role in protein secretion. Accumulation of
-amylase was also observed when teichoic acid synthesis was inhibited by culturing cells under phosphate restricted conditions. To further substantiate the involvement of teichoic acid in protein secretion teichoic acid less mutants were isolated on triptose blood agar medium. These mutants showed a remarkable decrease in the level of
-amylase secreted. It is suggested that the teichoic acid as a cel wall component of Gram positive bacteria might be related with protein secretion.
Flavor Components Produced by Microorganism during Fermentation of Korean Ordinary Soybean Paste
Song, Jae-Young ; Ahn, Cheol-Woo ; Kim, Jong-Kyu ;
Microbiology and Biotechnology Letters, volume 12, issue 2, 1984, Pages 147~147
In order to improve the quality and develop the new manufacture method of Korean ordinary soybean paste, this experiment was carried out to investigate microoganisms which produced the main flavor of Korean ordinary soybean paste. Microoganisms were isolated and identified. The components of flavor were extracted from culture broth and analyzed by gas chromatogram and the evaluation of sensory test. Isolated microoganisms were supposed as Bacillus sp., Mucor sp. and Penicillium spp. The flavor of culture broth produced by Bacillus sp. was similiar to that of Korean ordinary soybean paste in gas chromatogram and the evaluation of sensory test. The flavor of culture broth produced by Mucor sp. was a little similiar. The flavor of culture broth produced by Penicillium spp. were different.
Statistical Analysis for the Relationship between Gas Chromatographic Profiles of Korean Ordinary Soybean Paste Flavor and Sensory Evaluation
Jang, Jung-Kyu ; Kim, Jong-Kyu ;
Microbiology and Biotechnology Letters, volume 12, issue 2, 1984, Pages 153~153
In odrder tom improve the quality and develop the new manufacture method of Korean ordinary soybean paste, this experiment was carried out to investigate the peak in gas chromatogram wihich contributes mainly to the flavor of Korean ordinary soybean paste. Flavor components extracted from eithty species of Korean ordinary soybean paste were analyzed by gas chromatography. The relationship between the sensory scores of the Korean ordinary soybean paste flavor and the gas chromatographic data transformed with variables were analyzed by method of multiple regression analysis. The results obtained were summarized of follows: Simple correlation between values of each peak and sensory scores were totally low. The 31th peak had the highest correlation, 0.255 and the 29th peak was second, 0.216. Determination coefficients of data obtained by transformation of each variables were not significantly different from each other. Flavor of Korean ordinary soybean paste was explained about 68% at step 36 in case of stepwise multiple regression analysis of absolute values. The fact that the munimum standard errors of an estimate was found at the 36th step suggests the importance of selecting of independent variables forml the whole gas chromatogram together with the results of F ratio. In the contributing proportion of each peak examined, peak 29 and 31 were contributing mainly to the good flavor of Krean ordinary soybean paste. The flavor of Krean ordinary soybean paste were not explanied to single peak in gas chromatogram of the flavor. A cause of that might be thought to be the flavor of Korean ordinary soybean paste is explained to be a combination of each peak rather than single peak.
Microbial Production of Cellulosic Material Decomposing Enzymes (II)
Chung, Ki-Chul ;
Microbiology and Biotechnology Letters, volume 12, issue 2, 1984, Pages 165~165
Microscopic Vizualizaion of Protoplast Formation and Regeneration of Bacillus sphareicus
Han, Hyun-Jae ; Chung, Ha-Young ; Lee, Hyung-Hoan ;
Microbiology and Biotechnology Letters, volume 12, issue 2, 1984, Pages 175~175
Bacillus sphareicus 1953 K-5 was treated with 6M Urea and lysozyme (0.5mg/ml) separately in the typertonic mineral salts medium. As the result of the treatment, the bacillary Bacillus sphaericus was changed into L-shape and then protoplast. It was observed that the protoplast was multiplied by budding. When the protoplast was transferred into the free urea and lysozyme hypertonic mineral soft agar, it was regenerated into the bacillary from various in size.