• 미생물학회지
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• 제19권3호
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• pp.121-127
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• 1981

The constituents of molasses and effect of pH precipitate formation in molasses solution, vary according to its producing districts. The formation of precipitation is not so changeable in the range of buffering zone of molasses solution(pH4.3-6.3) in philippine molasses according to the change of pH value. On lower or higher than the range of buffering zone, the precipitation is increased from pH 4.3 to 2.8 and from 6.3 to 8.1, it is decreased when pH value is lower or higher than the pH value range. For molasses clarifying, it had better adjust the pH of molasses solution to neutral or weak alkali range out of the alkai side of the buffering zone, with lime solution. And then, add the calcium super phosphate solution to pH value of alkali side in buffering zone, as much as the pH of clarified molasses solution can reach to middle value in buffering zone. For the equilibrium of pH value on clarifying molasses, it takes plenty of time more than 6 hours.

• 한국식품조리과학회지
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• 제20권3호
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• pp.292-298
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• 2004

This study researched the microbial change of quality according to various phases of product flow of Dongtae-Jeon (a pan-fried dish) and rolled egg in packaged meals. In order to carry out the study, the time required, temperature, water activity and microbial quality were measured at various phases of production flow of Dongtae-Jeon and rolled egg in packaged meals, and the effects of these factors on microbial multiplication was analyzed. According to the phases in product flow of Dongtae-Jeon, it was shown that the time required is 12.5hrs and water activity is distributed 0.932-0.980. These conditions were suitable for microbial multiplication. According to the phases in product flow of rolled egg, it was shown that the time required is 3.3hrs. In addition, qualitative analysis of pathogenic microorganisms (Salmonella spp., Vibrio parahaemolyticus, Staphylococcus aureus) detected no such microorganisms in any of the samples.

• 미생물학회지
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• 제30권4호
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• pp.269-277
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• 1992

Several insertion mutants of Escherichia coli in the ant gene, coding for $Na^{+}$ $H^{+}$ antiport activity, showed littel, if any, reduction in the antiport activity. $Na^{+}$ dependent transport activity also remained at wild type level. These facts led to the idea that E. coli has evolved at least two distinct systems for extrusion of $Na^{+}$ The antiport activities were studied under various conditions to reveal different properties of these systems. For convenience these activities are referred to as major and minor activities. The distinguishing properties of the two systems include : kinetics (Km, Vm) at pH 7.8, competition pattern between $Na^{+}$ and Li$^{+}$ , pH profiles, pattern of the change in kinetic parameters as a function of pH, and sensitivity to protease, chemicals and heat.

• 미생물학회지
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• 제29권6호
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• pp.397-401
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• 1991

Yeast-form cells of cadmium ion-tolerant Hansenula anomala B-7 were changed to mycelial cells in medium containing more than $400\mu$g/ml of cadmium. Moreover, the mycelial cells were exchanged into clumped cells in a medium containing more than $1,000\mu$g/ml of cadmium. Optimal conditions of mycelial cell formation were achieved in the presence of .$1,000\mu$g/ml of cadmium with shaking cultivation for 7 days. Glucan and mannan contents of the yeast cell wall frown with $1,000\mu$g/ml of cadmium decreased by 10% compared with those grown without cadmium. However, protein and lipid contents increased about 20% respectively. By cadmium, no significant findings in specific amino acid contents were discovered.

• Journal of Microbiology
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• 제34권1호
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• pp.40-48
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• 1996

We have examined the chromatin structure of the HMRE/HSP82 and HMRa/HSP82 allels using three complementary approaches : DNase I chromating footprinting, micrococcal nuclease (MNase) nucleosome-protected ladder assay, and an in vivo E. coli dam methylase accessibility assay. The footprinting results indicate that the promoter and silencer sequences are assembled into nucleoprotein complexes which exhibit no detectable change in structure, despite a 70-fold range in expression levels. In addition, the promoter region of the HMRa/HSP82 allele is cleaved randomly by MNase in all cases, indicating the absence of anonical nucleosomes over this region irrespective of SIR4 or heat-shock. Finally, no discernible difference in the accessibility of the HMRE/HSP82 locus to dam methylase in SIR4 vs. sir4 cells was seenm which again suggests that the chromatin structure of HMRE/HSP82 allele is identical regardless of SIR4. Altogether, our results indicate that in contrast to other observations of the silent mating-type loci, no discernible structural alteration is detected at either HMR/HSP82 allele regardless of SIR genetic background or transcriptional state of the gene.

• Journal of Microbiology
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• 제45권1호
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• pp.75-78
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• 2007

Nucleotide and amino acid substitution pattern in vif gene of the Korean clade of HIV-1 isolated from Koreans were analyzed using consensus sequences. At nucleotide level, transition/transversion substitution ratio was 1.88, and nonsynonymous/synonymous substitution ratio was 2.67, suggesting a divergent evolution in the Korean clade. At amino acid level, there were 17 substitutions and $G{\rightarrow}E$ substitution at position 37 may be responsible for change in predicted secondary structure.

• 미생물학회지
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• 제10권3호
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• pp.117-127
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• 1972

To study the effect of IAA on the growth of Chlorella, the alage wre cultured on the media for six days by bubbling $_{2}$ enriched air under 10K lux at 20-$25^{\circ}C$. The culture media were made by adding a concentration of $10^{-3}$M, $10^{-4}$M, and 0M(as a control) IAA to the standard media. During the period of culture, Chlorella was smapled for the given time of interval and photosynthetic and respiratory activities were measured by Warburg manometer and change of chemical components of Chlorella was determined by spectrophotometry after the Chlorella cell was fractionated by Schmidt-Thannhauser method. 1) Photosynthetic and respiratory activities were enhanced by IAA ; especially the enhancement of respiratory activity was so remarkable. 2) As to the chemical components of Chlorella, carbohydrates and amino acids were reduced a little but phosphate, RNA, DNA, and protein were increased by $10^{-3}$M IAA ; the increase of RNA, in particular, was noticable. 3) The above results suggest that the enhancement of growth of Chlorella, by IAA and ATP induced by respiratory activity accelerated with IAA enhanced RNA synthesis, resulting in an increase of protein synthesis.

• 한국동물위생학회지
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• 제25권1호
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• pp.31-37
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• 2002

Major hazards existed in slaughterhouse are pathogenic microorganisms originated from intestinal microflora of slaughtered animals. This study was intended for the identification of microbial contamination sources during pork slaughtering in small plants. Total aerobic bacteria, Coliform group, Salmonella spp, Listeria monocytogenes, and Campylobacter jejuni/coli were isolated from the surface sample of pork carcasses. Contamination level among different sampling points of ham, belly and neck did not showed statistical differences. Therefore, the mixed sampling from belly and neck of carcass could be effective for microbiological monitoring. Isolation rates of pathogenic microorganisms showed Salmonella spp 20.9%, Listeria monocytogenes 10.5%, and Campylobacter jejuni/coli 8.1% from 296 sampling points. High prevalence rate of Salmonella spp indicated that the contamination of intestinal microflora occurred due to unsanitary processing control, which required HACCP system in small plants. It was recommended that the prerequisite program should be a key factor for a successful HACCP system implementation especially in small size slaughterhouse.

• 미생물학회지
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• 제26권2호
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• pp.137-142
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• 1988

pH decreased as the substrate mycelium developed, $\Delta$pH was 1.05-1.15, but increased after the aerial mycelium formation. The lactic acid content in culture solution showed no difference between 0.2% and 5% glucose, at which the aerial mycelium formation was repressed. The growth and development of mycelium was delayed by the lactate treatment. The activity of catalase was maximum in 24 hours after inoculation, and the wuperoxide dismutase activity showed a constant level during the developmental phases. The ascorbic acid accumulated after the aerial mycelium formation. The ascorbate oxidase isozyme of Rf 0.44 appeared, while the isozyme of Rf 0.36 desappeared during the development.

• Journal of Microbiology
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• 제40권2호
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• pp.173-177
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• 2002

In order to identify Yawowia lipolytica genes induced by serum, cDNA representational difference analysis was performed using a PCR-select CDNA subtraction method. One of the genes cloned from the subtraction was a gene (YIMBFl) homologous to Saccharomyces cerevisiae MBF1 encoding the coactivator multiprotein bridging factor 1. Disruption of YIMBFl revealed that the gene was net essential for viability, and the Ylmbf△ strain did not show any distinct phenotypic change on solid serum medium. In liquid medium, however. a difference was found in the ability to maintain hyphae induced by serum. This result suggests that the YIMbf1 protein may mediate transcriptional activation of certain genes involved in the hypha fonmation of Y. lipolytica.