• The Korean Journal of Mycology
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• v.32 no.2
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• pp.145-147
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• 2004

The ethyl acetate extracts from the liquid cultures of Coriolus versicolor, Phellinus linteus, and Hericium erinaceus showed significant antibacterial activities against Escherichia coli K88, E. coli K99, E. coli 987P, and Salmonella typhimurium 14058 causing bacterial diarrhea in Korean house pigs and chicken. Of these extracts, Coriolus versicolor extract showed the highest antibacterial activity. In addition, these extracts also showed significant growth inhibition against Staphylococcus aureus CARM3230 and E. coli CARM1381 which are known as kanamycin and ampicillin-resistant strains. These results showed that the mushroom extracts could be developed as a livestock feed additives that can replace commercial antibiotics, and also could be good resources for the development of a new antibacterial agent.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11b
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• pp.245-247
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• 2003

축산폐수에서 분리된 세균 S. sp1(S. capitis)와 S. sp2(3. xylosus)를 이용한 축산폐수 중 질소화합물 분해정도를 파악한 결과 1) 증식에 알맞은 조건은 LB broth, $27^{\circ}C$, pH7로 나타났다. 2) S. sp1은 배양 7일 초기 농도의 90.3%, 7일째 32.9%로 감소되어 14일까지 다소 증가하면서 유지되었다. 3) S. sp1과 S. sp2를 혼합배양한 결과 S. sp1과 S. sp2 단독배양보다 분해 효율이 높고 기간도 2일정도 단축되었다.

• Korean Journal of Microbiology
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• v.50 no.3
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• pp.254-260
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• 2014

Sulfur compound includes major electron acceptors for anaerobic respiration. In this study, cultivation-based study on sulfate- and sulfur-reducing bacteria of various wetlands of Korea was attempted. To isolate sulfate- and sulfur-reducing bacteria, anaerobic roll tube method was used to obtain typical black colonies of sulfate- and sulfur-reducing bacteria. Total 11 strains obtained were tentatively identified based on comparative 16S rDNA similarity and physiological property analysis. All sulfate-reducing bacteria (8 strains) belonged to genus Desulfovibrio with >99% 16S rDNA similarities. Three sulfur reducing bacteria were also isolated: two and one isolates were affiliated with Sulfurospirillum and Desulfitobacterium, respectively. These sulfate- and sulfur-reducing bacteria were able to utilize lactate and pyruvate and sulfite and thiosulfate as common electron donors and electron acceptors, respectively. This case study will provide fundamental information for obtaining useful indigenous sulfate- and sulfur-reducing bacteria from Korean wetlands employing various combinations of cultivation conditions.

• Korean Journal of Microbiology
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• v.36 no.2
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• pp.79-83
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• 2000

Activated sludge samples were collected from a municipal sewage treatment plant and used for enrichment of microbial consortia with aniline as the sole carbon and nitrogen source. Threc aniline-degrading bacteria were obtained lrom microbial consortia and an isolate which has excellent aniline degradability was selected for this study. The isolate was Gram-negative, and identified and designated as Delfha sp. JK-2 on the basis of various physiological and biochemical tests. 10 mM aniline was completely degraded within 24 hours after inoculation of the culture. Ammonium ion was liberated in the medium transiently during the incubation and disappeared when aniline was completely degraded. Addition of glucose as a supplementary source to aniline minimal media showed significant decrease in aniline degradat~on rate for the strain Effective degradation of aniline was achieved by the addition of 0.5% nitrate as a nitrogen source, and resulted in approximately 80% higher aniline degradation compared to the absence of nitrate. Phylogenetic analysis based on 16s [DNA sequence revealed that the strain was closely related to De@ia acidovorans, with 96% overall similarity. The 16s [DNA sequence of JK-2 was also found to be closely related to those of six other clonal types, including Acidovoru, Aquaspirillum. Xylophilus, Variovorm, and Rhodofernr.

• Journal of Korean Biological Nursing Science
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• v.9 no.1
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• pp.33-48
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• 2007

목적 : 본 연구에서는 한국인 소아의 침 및 성인의 질부로부터 분리한 1367개의 유산 생성 균주 중 4가지의 장내 병원성 세균;Methicillin-resistant Staphylococcus aureus(MRSA), Listeria monocytogenes, Salmonella typhimurium, Escherichia coli O157에 대해 발육억제 효과를 나타내는 유산 균주를 분리하고 분리된 균주의 Probiotic으로서의 가능성을 조사하고자 하였다. 방법 : 네 가지 병원성 세균을 대상으로 agar spot test와 Catalse test를 시행하여 1367개 균주 중 최종적인 실험대상 균주를 선정하였다. 최종 선정된 유산균과 네 가지 병원성 세균을 혼합 배양하여 병원성 세균증식 억제 효과를 보았다. 또한 최종균주의 probiotic으로서의 가능성을 확인하기 위해 균을 동정하고 내산성 등 몇 가지 특성을 관찰하였다. 결과 : Agar spot test 결과 전체의 15.7%에 해당하는 215 균주가 MRSA에 대해 억제 효과를 나타내었으며 215 균주 중 9.8%에 해당하는 21 균주가 L. monocytogenes에도 동시에 억제효과를 나타냈다. 이들 균주 중 가장 탁월한 효과를 보인 Lb 1250을 실험 대상 균주로 선정하였다. Lb(Lactobacillus) 1250과 상술한 병원성 세균을 각각 혼합 배양하면 Lb 1250 존재 하에서 MRSA의 증식은 $10^4$배 억제되었으며, L. monocytogenes는 $10^3$배의 억제 효과를 보였다. 그러나 S. typhimurium, E. coli O157에 대해서는 아주 미약한 효과를 나타냈다. Lb 1250의 몇 가지 특성을 조사한 결과 Lactobacillus delbrueckii subsp. delbrueckii로 동정되었으며, 이는 $H_{2}O_2$를 잘 생산해 내는 균주이었다. 또한 이 균주는 우유에서 curd를 약하게 생성하며 이 curd의 향은 달콤하고 최종 pH가 4.6까지 감소하였으며, pH 2와 같은 강산의 조건하에서 배양한 결과 2시간 후에도 상당한 생존도를 유지하였다. 결론 : 이상의 결과에서 Lb 1250은 병원성 세균의 성장을 억제함을 관찰하였고, probiotic으로서의 이용가능성을 확인하였다.

• 한국해양학회지
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• v.28 no.2
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• pp.79-85
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• 1993

The final biomass yields of 16 marine phytoplankton clones were measured in media with different levels of iron and phosphorus concentrations. The biomass yields of oceanic clones were either only slightly limited or not limited by iron, and those of coastal clones were severely limited by iron in all photogenetic groups other than cyanobacteria. By contrast oceanic cyanobacteria clones as well as coastal clones required higher iron concentrations: minimum concentrations of iron addition for detectable growth of the Synchronous species were estimated to fall between $10^{-9}{\;}and{\;}10^{-8}{\;}M$. Not only the habitat differences (oceanic-coastal trends) but also the photogenetic differences of the oceanic phytoplankton species in the response to the iron enrichments deserve very careful attention before ocean iron fertilization.

• Microbiology and Biotechnology Letters
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• v.45 no.3
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• pp.185-199
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• 2017

Methane, which is emitted from natural and anthropogenic sources, is a representative greenhouse gas for global warming. Methanotrophs are widespread in the environment and play an important role in the biological oxidation of methane via methane monooxygenases (MMOs), key enzymes for methane oxidation with broad substrate specificity. Methanotrophs have attracted attention as multifunctional bacteria with promising applications in biological methane mitigation technology and environmental bioremediation. In this review, we have summarized current knowledge regarding the biodiversity of methanotrophs, catalytic properties of MMOs, and high-cell density cultivation technology. In addition, we have reviewed the recent advances in biological methane mitigation technologies using methanotrophs in field-scale systems as well as in lab-scale bioreactors. We have also surveyed information on the dynamics of the methanotrophic community in biological systems and discussed the various challenges pertaining to methanotroph-related biotechnological innovation, such as identification of suitable methanotrophic strains with better and/or novel metabolic activity, development of high-cell density mass cultivation technology, and the microbial consortium (methanotrophs and non-methanotrophs consortium) design and control technology.

• Journal of Mushroom
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• v.13 no.2
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• pp.97-102
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• 2015

This study was conducted to investigate optimum conditions for mass production of antagonistic microbes Pseudomonas azotoformans HC5. P. azotoformans HC5 is a potent biological control agent to control brown blotch disease caused by Pseudomonas tolaasii. This markedly showed the antagonistic activity against P. tolaasii, the most destructive pathogen of cultivated mushrooms. To define the optimum conditions for the mass production of the P. azotoformans HC5, we have investigated optimum culture conditions and effects of various nutrient source on the bacterial growth. The optimum initial pH and temperature were determined as pH 6.0 and $15^{\circ}C$, respectively. The optimal concentration of medium elements for the growth of pathogen inhibitor bacterium was determined as follows: 0.6% adonitol, 1.5% yeast extract, 0.8% $NH_4H_2PO_4$, 5mM $MgSO_4$, and 0.2% asparagine.

• Journal of Mushroom
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• v.14 no.4
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• pp.191-196
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• 2016

This study was conducted to investigate optimum conditions for mass production of ntagonistic microbes Alcaligenes sp. HC12. Alcaligenes sp. HC12 had a potent biological control agent to control browning disease caused by Pseudomonas agarici. Alcaligenes sp. HC12 markedly showed the antagonistic activity against Pseudomonas agarici, the most destructive pathogen of cultivated mushrooms. To define the optimum conditions for the mass production of the Alcaligenes sp. HC12, we have investigated optimum culture conditions and effects of various nutrient source on the bacterial growth. The optimum initial pH and temperature were determined as pH 9.0 and $30^{\circ}$, respectively. The optimal concentration of medium elements for the growth of pathogen inhibitor bacterium(Alcaligenes sp. HC12) was determined as follows: 0.5% dextrine, 1.5% yest extract, 1.0% $NaNO_3$, 0.5% $KH_2PO_4$, and 1.5% asparagine.

• Korean Journal of Microbiology
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• v.44 no.2
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• pp.130-134
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• 2008

Modern automated culture systems have increased the isolation rate of microorganisms and shortened the time to detection, reducing experimental errors in diagnosis of infecting agents. BacT/ALERT 3D system is based on the colorimetric detection of $CO_2$ produced by the growing microorganisms. In order to evaluate the efficiency of the detection system, sterility test were performed using 6 bacteria. With standard aerobic and anaerobic bottles containing the liquid media, both three aerobic bacteria (P. aeruginosa, M. luteus, B. subtilis) and a facultative bacterium S. aureus were detected up to 1 CFU in 31.44 hr. In addition, growth of anaerobic C. sporogenes was recognized up to 1 CFU in 15.96 hr. The slowly growing bacteria P. acnes was detected up to 10,000 CFU in 129.36 hr. In comparison with conventional culture method, BacT/ALERT 3D automated culture system was more sensitive and saved detection time up to$2\sim10$ hr. Therefore, this automated culture system enables to efficiently detect bacteria in clinical samples and biological medicines.