• 미생물학회지
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• 제21권3호
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• pp.156-162
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• 1983

Conditions for effcient formation and regeneration of protoplasts of Micromonospora rosaria and Micromonospora purpurea were investigated. The state of inoculm, culture stage and growth in a medium containing partially growth-inhibiting concentration of glycing have significant effects on portoplasting. A high frequency of regeneration (up to 30%) was accomplished with a hypertonic regeneration agar medium defined by Okanishi for Strptomyces. Using the optimal conditions for protroplasting and regeneration, protoplast fusion of auxotrophic M.rosaria was carried out. Polyethylene glycol 1,000 was chosen for fusogenic agent. When signgle auxotrophs were used, the recombinant frequency of auxortrophic markers varied from 1.3 to 3.2%. Using two double auxotrophs, the recombinant frequencies of 0.7-4.3% were obtained. Much lower frequencies(three or more orders of magnitude) were observed by the conventional matings.

• Journal of Microbiology
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• 제34권1호
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• pp.74-81
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• 1996

Two secretion vectors, pUBA240 and pUB340 were constructed by using the promoter and secretory signal region of the .alpha.-amylase gene from an .alpha.-amylase hyperproducing strain, Bacillus subtilis NA64. In this secretion vector system, various restriction enzyme sites are located immediately after the proregion of the .alpha.-amylase gene for easy replacement of various foregn structural genes. To evaluate this secretion vectors, the .betha.-lactamase gene of pBR322 was used as a reporter gene. The expressed and biologically active .betha.-lactamase was secreted into the culture broth from B. subtilis LKS86 transformants harboring each .betha.-lactamase secreting plasmid, pUBAbla and pUBSble. In both cases, more than 92% of expressed .betha.- lactamases were located idn the culture medium. The amount of the secreted .betha.-lactamase was about 80% of the total secreted proteins in the culture medium.

• 미생물학회지
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• 제13권1호
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• pp.31-36
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• 1975

Chlorella ellipsoidea cells were cultured in a phosphate, magnesium, sulfur or potassium-free medium. Some portions of cells were taken out at intervals during the culture, and physiological activities such as growth rate, reproduction, photosynthetic activity, and biosynthesis of cholorophyll of macro-element deficient cells were measured. 1) Generally, growth rate, reproduction, photosynthetic activities, and biosynthesis of chlorophyll of the macro-element deficient cells decreased more or less, compared with those of the normal cells. 2) The growth and reproduction of the algal cells in sulfur, or magnesium free medium were retarted severely with the chlorosis ; the photosynthetic activity and the content of chlorophyll showed the same tendency. 3) It is considered that the decrease in growth rate of macro-element deficient Chlorella cells is due to the decrease in photosynthetic activity owing to the decrease in chlorophyll content of the cells.

• 미생물학회지
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• 제24권2호
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• pp.141-146
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• 1986

To find the role of polyphenol oxidase in lignin biodegradation, chracteristics of extracellular polyphenol oxidase activity from Lentinus edodes JA01 was investigated. Polyphenol oxidase had its optimum activity at pH 4.5 and $45^{\circ}C$ respectively. Also, the enzyme was very unstable in various pHs and comparatively heat stable up to $60^{\circ}C$. In $lignosulfonate-NH_4$ salts medium, the growth rate of L.edodes JA 01 was relatively slow and polyphenol oxidase activity appeared 2 and 14 days after inoculation. No significant relationships were found between polyphenol oxidase activity and the amounts of lignosulfonate present in the culture medium.

• 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.

• 미생물학회지
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• 제5권2호
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• pp.86-92
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• 1967

By cylinder-plate method was the antibiosis of 15 strains of Aspergilli examined, which were isolated from Korean "Meju" collected through all over South-Korea. The results are as follows; 1) Only two strains of Aspergilli (strain 1 and 9) sellected in screening test have antibiosis for the several gram positive and negative bacteria. 2) The activity of antibiotic produced by strain I was excellent, having been cultured at 25.deg.C in the Malt-infusion Czapek's medium of pH 3.5 to 7.5 for 6 days. 3) The activity of antibiotic produced by strain 9 was excellent, having been cultured at 25.deg.C in the Czapek's medium of pH 4.5 to 6.5 for 6 days. 4) When Aspergilli were cultured under optimum conditions which resulted, by experiments, the activity of antibiotic produced by Aspergilli was stronger than activity of 10.gamma./ml. streptomycin.eptomycin.

• 미생물학회지
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• 제18권4호
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• pp.180-187
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• 1980

Streptococcus mutans에 의한 sucrose로 부터 축적된 polysaccharide를 조사한 결과 1 균주이 따라 36시간 후 4.41mg/ml로 부터 1.86mg/ml사이의 polysaccharide가 축적되고 2 효소에 의해서도 10시간 후 2.36mg/ml에서 1.4mg/ml의 polysaccharide가 생성되고 3 생성된 polysaccharide는 통일형의 polysaccharide였다.

• 미생물학회지
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• 제53권2호
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• pp.118-122
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• 2017

납, 아연, 카드뮴에 의한 미생물 생장 저해를 변형된 Tris minimal medium을 사용하여 측정하였다. Escherichia coli 균주에 대한 독성의 세기는 아연 > 카드뮴 > 납 순으로 나타났고 Streptomyces coelicolor A3(2)의 철 함유 superoxide dismutase 2를 과발현하는 E. coli 균주는 중금속 저항성이 증가되었음을 알 수 있었다.

• 미생물학회지
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• 제6권1호
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• pp.22-28
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• 1968

Chlorella ellipsoidea cells were cultured in an iron, copper, zinc, manganese, molybdenum or boron-free medium. Biosynthetic activities of nucleic acids, protein and phospholipid in chlorella cells, which were growing in a microelement deficient medium were compared with those of the normal cells by measuring the contents of phosphate, amino acids or UV-absorbing substances in the various cell fractions. When the algae were grown in a molybdenum-free medium, the amounts of phosphate in the acid-soluble fraction of the cells increased, whereas the amounts of alkali-stable protein and RNA decreased compared with the normal cells showing that the synthesis of protein and RNA from the early products of photosynthesis was inhibited. When the algae were grown in a boron-free medium, amounts of alkali-labile protein and phospholipid of the cells decreased, while the amount of phosphate in acid-soluble fraction increased compared with the normal cells showing that the biosynthesis of protein and phospholipid from the early products of photosynthesis was retarded. In general, amounts of protein and RNA in the microelement deficient cells significantly decreased compared with those of the normal cells. Phosphate content in the acid-soluble fraction of the algal cell grown in an zinc, copper, molybdenum, or boron-free medium increased considerably, whereas that of the algal cell grown in an iron or manganese-free medium decreased remarkably compared with that of the control. It is considered, therefore, that molybdenum, zinc, copper and boron etc. play an important role in the biosyntbesis of macromolecule from acid-soluble phosphate compounds, in contrast to the principal action of iron and manganese on the photosynthetic process itself.

• Journal of Microbiology
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• 제44권6호
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• pp.583-590
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• 2006

In this study, an organic solvent tolerant bacterial strain was isolated. This strain was identified as Pseudomonas sp. strain S5, and was shown to degrade BTEX (Benzene, Toluene, Ethyl-Benzene, and Xylene). Strain S5 generates an organic solvent-tolerant lipase in the late logarithmic phase of growth. Maximum lipase production was exhibited when peptone was utilized as the sole nitrogen source. Addition of any of the selected carbon sources to the medium resulted in a significant reduction of enzyme production. Lower lipase generation was noted when an inorganic nitrogen source was used as the sole nitrogen source. This bacterium hydrolyzed all tested triglycerides and the highest levels of pro-duction were observed when olive oil was used as a natural triglyceride. Basal medium containing Tween 60 enhanced lipase production to the most significant degree. The absence of magnesium ions ($Mg^{2+}$) in the basal medium was also shown to stimulate lipase production. Meanwhile, an alkaline earth metal ion, $Na^+$, was found to stimulate the production of S5 lipase.