• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1979.10a
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• pp.236-238
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• 1979

자연계에 배출되는 유기물함유폐수는 Figl 에 나타난 바와 같이 미생물의 생태적변동에 의해 정화된다. (표 1참조)이 자연현상을 인공장치에 의해 효율좋게 정화시키는 연구를 20수년전부터 개시하여 Test plant 및 Pilot plant을 작제하여, 검토하여 현재는 Fig. 2.에 나타난 바와 같은 실용화 plant가 다수, 가동하게 되었다. Fig. 2의 flow pheet를 개약설명한다. 먼저 폐수원액은 vibrating filter를 통과시키므로서 고형물은 제거된다. 이 용액을 구기조(Aeration tank)에 투입하여, 맹렬히 통기하면서, 호기분해를 행한다. 1 일간, 포기후, 호기성균체를 포함한 용액을 다음의 광합성세균배양조에 이행시켜, 4 일간 체류시키므로서 광합성세균등을 증식시킨다. 그후 응집침전제를 첨가하여, 광합성세균등의 Bacterial mass는 회수된다. 그 상맥부는 최종적으로 포기되고, (동기, 한랭에 있어서는 산포여상 Contact oxidation tower를 통과시킨다.) 소량의 침전제을 분리한 후 방류한다, 광합성세균이용에 의한 수처리기술의 특징은 1) 농후유기폐수를 희석하지 않고 정화처리할 수 있다. 2) 표3에 나타난 바와같이 적용할 수 있는 폐수의 종류는 많다. 3) 부산물로서 회수한 균체는 축산사료나 수산사료로서 이용할 수 있다. 표4 및 표5는 산난계 및 부화직후의 치어의 첨가사료 로서 이용한 일예이다.

• Korean Journal of Microbiology
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• v.22 no.4
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• pp.243-247
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• 1984

The effect of the heavy metals copper and cadmium on the natural populations of surface microlayer and subsurface water was investigated. Two microbiological parameters, number of colony-forming bacteria and $^{14}C-glucose$ uptake rate, were evalated. The two natural bacterial populations showed different tolerances of the heavy metals. The ingibition of bacterial growth and activity occurred more strongly in the 1m-depth samples than in neuston populations. The results support the existence of autochthonous bacterioneuston populations in marine environment.

• Economic and Environmental Geology
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• v.34 no.4
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• pp.345-354
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• 2001

The effects on arsenic geochemistry of indigenous microorganisms isolated from an area contaminated with high concentration of arsenic were investigated. Arsenite exerted higher inhibitory effects on the microbes' growth than arsenate. During incubation of the microbes in an arsenate-spiked medium over 24 hours, decrease in microbial growth was observed as arsenate content increased. Arsenate of 150 mM or over apparently inhibited cell growth. However, further incubation for up to 4 days in the high arsenate concentration medium resulted in cell growth, implying that the microorganisms adjusted their biochemical functions to detoxify arsenic and maintain growth. Two types of microbes were observed during 20 hours to reduce arsenate to arsenite in solution through a detoxification mechanism. As well, decrease in the total arsenic content occurred over a 4-day incubation with the same microbes in an arsenate-spiked medium. Therefore it is suggested that microorganisms can influence arsenic speciation in natural settings and this may be applied to efficient bioremediation of arsenic-contaminated sites.

• Feed Journal
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• v.2 no.8
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• pp.60-67
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• 2004

항생제는 병원성 미생물 및 그 밖의 유해한 세포의 발육 또는 기능을 억제하는 물질로써, 가축의 사료에 이러한 항생제를 첨가하여 급여하게 되면 장내에서 유해한 미생물의 증식과 발육을 억제하고 정상적인 균총을 유지함으로써 질병을 예방할 수 있으며, 과도한 장내 미생물의 증식에 의한 불필요한 영양소 손실을 막고 영양소의 소화와 흡수촉진 및 사료 섭취량을 증진시키는 등의 효과를 얻을 수 있기 때문에, 축산업에서 가축의 생산성 향상 및 질병예방을 위하여 일정수준의 항생제가 첨가된 배합사료를 급여하는 것이 일반적이었다.(중략)

• Journal of Life Science
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• v.31 no.12
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• pp.1079-1087
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• 2021

To analyze gut microbiota of livestock in Korea and compare taxonomic differences, we conducted 16S rRNA metagenomic analysis through next-generation sequencing. Fecal samples from broiler chickens, pigs, and cattle were collected from domestic feedlots randomly. α-diversity results showed that significant differences in estimated species richness estimates (Chao1 and ACE, Abundance-based coverage estimators) and species richness index (OUTs, Operational taxonomic units) were identified among the three groups. However, NPShannon, Shannon, and Simpson indices revealed that abundance and evenness of the species were statistically significant only for poultry (broiler chickens) and mammals (pigs and cattle). Firmicutes was the most predominant phylum in the three groups of fecal samples. Linear discriminant (LDA) effect size (LEfSe) analysis was conducted to reveal the ranking order of abundant taxa in each of the fecal samples. A size-effect over 2.0 on the logarithmic LDA score was used as a discriminative functional biomarker. As shown by the fecal analysis at the genus level, broiler chickens were characterized by the presence of Weissella and Lactobacillus, as well as pigs were characterized by the presence of provetella and cattele were characterized by the presence of Acinetobacter. A permutational multivariate analysis of variance (PERMANOVA) showed that differences of microbial clusters among three groups were significant at the confidence level. (p=0.001). This study provides basic data that could be useful in future research on microorganisms associated with performance growth, as well as in studies on the livestock gut microbiome to increase productivity in the domestic livestock industry.

• Korean Journal of Food Science and Technology
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• v.42 no.3
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• pp.281-286
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• 2010

The objective of this study was to analyze the microbial populations in the raw ingredients of kimchi and their changes during an automated commercial manufacturing process. High population numbers of total aerobic bacteria, lactic acid bacteria, Leuconostoc sp., and yeast were detected in garlic, ginger, red pepper powder and this result revealed that these ingredients were the major source of microbials in kimchi. Additionally, during the salting process of Chinese cabbage, rapid microbial growth was observed and the consecutive washing process was determined to be ineffective, lowering the microbial count by only one log reduction. Yeast was also detected in various ingredients. These results strongly suggest that, in order to lower the microbial population numbers in kimchi, the side-ingredients and salting process should be subjected to the appropriate sanitization or sterilization processes at the HACCP level. Beside, treatment of salted Chinese cabbage with sodium hypochlorite solutions after the salting step is recommended. To inhibit yeast growth, appropriate chemical treatment and approval of additive uses to control microbials should be considered. These experimental results and suggestions will be used to improve the kimchi manufacturing process in factories.

• Food Engineering Progress
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• v.15 no.4
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• pp.370-375
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• 2011

In this study the polymerase chain reaction (PCR) combined with denaturing gradient gel electrophoresis (DGGE) was evaluated as a method permitting the rapid detection of pathogens in fresh originally grown vegetables. A universal primer (341GCf/534r) was selected for its ability to amplify the V3 region of 16S-rRNA genes in their target pathogens (Salmonella typhimurium, Pseudomonas fluorescens, Bacillus cereus, Listeria monoytogenes, Staphyloocus aureus, E. coli). The 194 bp fragments in PCR were successfully duplicated as expected. The amplified fragments of the same size from six different pathogens also showed good separation upon DGGE. The detection limit of PCR-DGGE for six pathogens in fresh-cut lettuces were over $10^{5}$ CFU/g when sampled by stomaching. However, when the sampling method was changed from stomaching to shaking, the detection limit of six pathogens in organic vegetables was shown to increase by over $10^{1}$ CFU/g, but only those of B. cereus were over $10^{3}$ CFU/g. Therefore, PCR-DGGE was shown to be a reliable method for the detection of pathogens in fresh-cut vegetables.

• Journal of Life Science
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• v.15 no.1 s.68
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• pp.136-140
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• 2005

Microbial cell-based UV spectrometric assay for the quantitative measurement of epoxide hydrolase activity was evaluated and optimized for the efficient screening of whole cell activity of novel epoxide hydrolase. Epoxide hydrolase activity was determined by measuring the increase of the oxidized product, benzaldehyde. The effects of the concentrations of phenyl-1,2-ethanediol, sodium metaperiodate and cells were optimized for epoxide hydrolase-catalyzed hydrolysis of styrene oxide. The relevant kinetic parameters of Km and $V_{max}$ for the hydrolysis of (R)-styrene oxide by Rhodotorula glutinis were determined from Lineweaver-Burk plot as 41.2 nmol/min$\cdot$mg dcw and 7.5 mM respectively, and coincided well with those from GC analysis.

• Bioindustry News
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• v.21 no.1
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• pp.12-14
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• 2008

• 대한치과보철학회:학술대회논문집
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• 1997.11a
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• pp.63-63
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• 1997