• 한국미생물·생명공학회지
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• 제20권6호
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• pp.687-692
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• 1992

혼합배양중의 각 미생물의 생균수 측정은 순수배양보다 훨씬 복잡하다. 특히 두 균주의 크기가 비슷한 경우에는 사용할 수 있는 방법이 더 제한된다. 본 연구에서는 두 균의 크기가 비슷한 경우에도 적용될 수 있는 간단한 생균수 측정방법을 개발하였다. 미생물 배양액의 산소흡수속도(OUR)는 세포수에 비례하며 이때의 비례상수인 최대 비산소흡수속도( maximum specific OUR)를 알고 있으면 배양액의 OUR을 측정함으로써 간접적으로 생균수를 구할 수 있게된다. 혼합배양의 경우 산소흡수속도는 각 미생물의 호흡속도의 합이 되며, 각 미생물의 호흡속도가 서로 다르고 또한 온도의존성이 다르다면 호흡속도의 측정을 이용하여 각 생균수를 간접적으로 측정할 수 있다.

• Journal of Periodontal and Implant Science
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• 제29권1호
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• pp.265-276
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• 1999

This study was performed to evaluate the effect of hydrogen peroxide-producing Lactobacillus acidophilus V-20onthe replication of periodontal pathogens, Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis. When A. actinomycetemcomitans and P. gingivalis were incubated alone and in the combination with L. acidophilus V-20, the viable cell numbers of A. actinomycetemcomitans and P. gingivalis were compared between those cultures. The effect of S. mutans, E. durans, and L. lactis on the replication of A. actinomycetemcomitans and P. gingivalis was also evaluated. The change of periodontal indexes(probine depth, gingival index, GCF volume) and the viable cell numbers of A. actinomycetemcomitans and black pigmented bacteroides in subgingival plaque sample were evaluated following gargling of fermented milk made from L. acidophilus V-20 for 1 month on patients with periodontal disease in maintenance phase. In the mixed culture of L. acidophilus V-20 and A. actinomycetemcomitans or P. gingivalis, the replication of A. actinomycetemcomitans or P. gingivalis wascompletely inhibited. But in the mixed culture of P. gingivalis and hydrogen peroxide-nonproducing Lactobacillus casei, the viable ceil numbers of P. gingivaliswas not decreased when compared with the numbers in the mixed culture of P. gingivalis and L. acidophilus V-20. In the mixed culture of A. actinomycetemcomitans and S. mutans, E. durans, or L. lactis, the viable cell number of A. actinomycetemcomitans was not almost changed when compared with the numbers in the culture of A. actinomycetemcomitans alone. And in the mixed culture of P. gingivalis and E. durans or L. lactis, the viable cell numbers of P. gingivaliswas not almost changed compared with the counts in the culture of P. gingivalis alone. But the replication of P. gingivalis was completely inhibited in the mixed culture of P. gingivalis and S. mutans. When the change of periodontal indexes following gargling of fermented milk was compared with baseline, probing depth and gingival index were not changed, but GCF volume was significantly decreased(p<0.05). And when the viable ceil numbers of microorganisms in subgingival plaque sample were compared with baseline, total viable ceil number was almost unchanged and the viable cell numbers of A. actinomycetemcomitans and black pigmented bacteroides were significantly decreased(p<0.05). These results suggest that L. acidophilus V-20 inhibit the replication of A. actinomycetemcomitans and black pigmented bacteroides by the formation of hydrogen peroxide.

• Journal of Microbiology and Biotechnology
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• 제25권11호
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• pp.1928-1935
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• 2015

Microbial growth kinetics is often used to optimize environmental processes owing to its relation to the breakdown of substrate (contaminants). However, the quantification of bacterial populations in the environment is difficult owing to the challenges of monitoring a specific bacterial population within a diverse microbial community. Conventional methods are unable to detect and quantify the growth of individual strains separately in the mixed culture reactor. This work describes a novel quantitative PCR (qPCR)-based genomic approach to quantify each species in mixed culture and interpret its growth kinetics in the mixed system. Batch experiments were performed for both single and dual cultures of Pseudomonas putida and Escherichia coli K12 to obtain Monod kinetic parameters (μ_max and K_s). The growth curves and kinetics obtained by conventional methods (i.e., dry weight measurement and absorbance reading) were compared with that obtained by qPCR assay. We anticipate that the adoption of this qPCR-based genomic assay can contribute significantly to traditional microbial kinetics, modeling practice, and the operation of bioreactors, where handling of complex mixed cultures is required.

• Applied Biological Chemistry
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• 제51권1호
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• pp.17-23
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• 2008

본 연구는 산머루를 이용한 과실주의 발효시 원료 등에서 기인한 강한 산미에 의한 과실주의 품질을 저하시키는 것을 개선시키기 위하여 혼합균주의 접종에 의한 알코올 발효 과정중 다양한 혼합배양 조건으로 감산발효를 시도하였다. 산머루 알코올 발효균주로 사용된 Saccharomyces sp. SMR-3 배양구에 Schizosaccharomyces pombe와 Schizosaccharomyces japonicus를 각각의 감산발효균주로 접종 후 혼합배양 한 결과, 산머루 알코올 발효균주 Saccharomyces sp. SMR-3에 Schizosaccharomyces pombe를 $22^{\circ}C$, 12일간 혼합 배양한 처리구가 알코올 함량 $15.8{\pm}0.2%$로 최대였고, 산도 $0.44{\pm}0.02%$, 총 유기산 함량 $648.96{\pm}7.14mg%$ , malic acid $99.30{\pm}1.24mg%$ 로 가장 낮게 나타나, 알코올 발효균주 단독으로 배양한 처리구 보다 알코올 함량은 2% 이상 높았고, 산도는 51.65%, 총 유기산은 48.02% 및 malic acid는 81.12%의 감소 효과를 나타내어 최적의 감산발효 조건으로 나타났다.

• International Journal of Advanced Culture Technology
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• 제11권2호
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• pp.162-169
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• 2023

With the diversified development of modern art, the application of mixed media in painting has become increasingly prominent, which not only provides artistic creators with new creative ideas, but also magnifies the creators' emotions and re endows the media with meaning and value. This paper systematically introduces the definition, features and connotation of mixed media painting, and expounds three aspects of the aesthetic function of multimedia in oil painting creation, the embodiment of painting individuality, and the combination and application of materials and technique to demonstrate that mixed media presents different understanding and expression in Chinese oil painting, no longer constrained by traditional oil painting materials, which promotes more development possibilities of the art expression form of Chinese oil painting, enhances its international influence, and bring new vitality to the creation and development of Chinese oil painting.

• 한국물환경학회지
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• 제28권6호
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• pp.796-803
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• 2012

Potential feasibility of nutrients removal and biofuel production with microalgae was evaluated in batch culture. Distribution of microalgae in fresh water including reservoir and river was investigated to search for the species with high content of lipid that could converted into biofuel. Green algae, Chlorella and Scenedesmus sp., these are known as species containing high lipid content for biodiesel production, were observed in both summer and autumn season. However another highly lipid-containing species, botryococcus sp. was not observed in this study. In mixed culture of microalgae using synthesized wastewater medium, green algae were found to be dominant, comparing to other species of diatoms and blue-green algae. And microalgae were also capable of removing nitrogen and phosphorus in batch experiments. During the culture period of 14 days, removal efficiencies of nitrate and phosphorus were 30% and 82%, respectively. Furthermore, content of the intracellular lipid extracted from algae cell was as favorable as 12-30% in the mixed culture where Scenedesmus and Chlorella sp. were dominant. Therefore the mixed culture of microalgae could be applied to biofuel production and tertiary wastewater treatment, even though there are economic barriers to overcome.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제38권1호
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• pp.14-19
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• 2012

Introduction: This study was conducted to evaluate ssrA expression resulting from adaptation of Escherichia coli (E. coli) to oral pathogens through signal exchange. Materials and Methods: Human cell lines Hep2 and HT29, wild-type E. coli (WT K-12), ssrA knock-out E. coli (${\Delta}K$-12), and Scleropages aureus (S. aureus) were used. A single culture consisting of Hep2, HT29, WT K-12, and ${\Delta}K$-12, and mixed cultures consisting of Hep2 and WT K-12, Hep2 and ${\Delta}K$-12, WT K-12 and S. aureus, ${\Delta}K$-12 and S. aureus, and Hep2, WT K-12, and S. aureus were prepared. For HT29, a mixed culture was prepared with WT K-12 and with WT K-12 and S. aureus. Total RNA was extracted from each culture with the resulting expression of ssrA, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-${\kappa}B$), and p53 was evaluated by Reverse transcription polymerase chain reaction (RT-PCR). Results: The expression of ssrA in a single culture of WT K-12 was lower than that observed in the mixed culture of WT K-12 with S. aureus. Greater ssrA expression was observed in the mixed culture of WT K-12 with Hep2 than in the single culture of WT K-12. The expression of NF-${\kappa}B$ was higher in the mixed culture of Hep2 with ${\Delta}K$-12 than that in the mixed culture of Hep2 with WT K-12, and was lowest in the single culture of Hep2. The expression of ssrA was higher in the mixed culture of WT K-12 with Hep2 and S. aureus than in the mixed culture of WT K-12 with Hep2. Conclusion: These results suggest that ssrA plays an important role in the mechanism of E. coli adaptation to a new environment.

• Journal of Microbiology and Biotechnology
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• 제6권2호
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• pp.116-119
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• 1996

The biological treatment by a mixed culture GE2 immobilized on activated carbon was investigated with a phenolic resin industrial wastewater containing 41,000 mg/l of phenol and 2,800 mg/l of formaldehyde. At a dilution of 20 times with aerated tap water, influent and effluent $COD_{Mn}$ were 4,587 mg/l and 46 mg/l, that is, $COD_{Mn}$ removal efficiency was 99.0%. At this time, phenol and formaldehyde con-centration of the effluent were 1.24 and 6.80 mg/l, indicating removal efficiencies of 99.9 and 94.1%, respectively.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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• pp.147-152
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• 2004

Aerobic cometabolism of cis-1,2-dichloroethylene (c-DCE) and c-DCE epoxide by a butane-grown mixed culture was evaluated. Transformation of c-DCE resulted in the concomitant generation of c-DCE epoxide. Chloride release studies showed nearly complete oxidative dechlorination of c-DCE (approximately 75%). Mass spectrometry confirmed tile presence of a compound with mass-to-charge-fragment ratios of 112, 83, 48, and 35. The values are in agreement with the spectra of a chemically synthesized c-DCE epoxide. Some evidences indicating the involvement of the monooxygenase in the transformation of c-DCE epoxide are: 1) $O_2$ requirement for c-DCE transformation and butane degradation; 2) butane inhibition on c-DCE transformation and vice versa; 3) the inactivation of c-DCE and c-DCE epoxide transformations by acetylene (a known monooxygenase inactivator); and 4) tire inhibition of c-DCE epoxide transformation by c-DCE.

• KSBB Journal
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• 제6권4호
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• pp.363-368
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• 1991

PVA degrading bacteria were isolated from water system, and identified as Pseudomonas cepacia and Pseudmonas pseudomallei, which were named as Pseudomonas sp. G5Y and Pseudomonas sp. PW. It was found out that those two kinds of bacteria have a symbiotic relationship to degrade PVA. For the mixed culture of these bacteria, the optimal conditions of pH, temperature, nitrogen source, and polymerization degree of PVA were found to be 7.5, $35^{\circ}C$, ammonium sulfate, and 500, respectively. Also, the growth of these bacteria was promoted by trace elements such as vitamin B1, B12, pyridoxine, and p-aminobenzoate, respectively. The specific growth rate of mixed bacteria was inhibited when the concentration of PVA was more than 20g/l. The substrate inhibition kinetics of the mixed culture was $${\mu}=\frac{0.065S}{2.56+S+(S^2/156}hr^{-1}$