• Journal of Microbiology and Biotechnology
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• 제22권5호
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• pp.674-683
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• 2012

A new strain, SD12, was isolated from tannery waste polluted soil and identified as Pseudomonas aeruginosa on the basis of phenotypic traits and by comparison of 16S rRNA sequences. This bacterium exhibited broad-spectrum antagonistic activity against phytopathogenic fungi. The strain produced phosphatases, cellulases, proteases, pectinases, and HCN and also retained its ability to produce hydroxamate-type siderophore. A bioactive metabolite was isolated from P. aeruginosa SD12 and was characterized as 1-hydroxyphenazine ((1-OH-PHZ) by nuclear magnetic resonance (NMR) spectral analysis. The strain was used as a biocontrol agent against root rot and wilt disease of pyrethrum caused by Rhizoctonia solani. The stain is also reported to increase the growth and biomass of Plantago ovata. The purified compound, 1-hydroxyphenazine, also showed broad-spectrum antagonistic activity towards a range of phytopathogenic fungi, which is the first report of its kind.

• 생명과학회지
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• 제9권3호
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• pp.314-327
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• 1999

This study was investigated to isolate identify the total bacteria and fungi from the indoor air of work-place of the shoes, paint, stainless steel, and plastic industries. The number of bacterial colonies on the nutrient agar plates were calculated by the open petridish method for 30 minutes in indoor air of work-places at the autumn and winter. The isolated bacteria were identified by Gram stain and biochemical test using API Staph and API 20E kits. The isolated fungal colonies were identified by gross appearance of the giant colonies and microscopic examination of their spore and hyphal characteristics on the slide culture method. The minimum inhibitory concentration (MIC) of several antibiotics against isolated bacteria was determined by the microdilution method with Mueller-Hinton broth. The 70-400 colonies in autumn and 54-236 colonies in winter were isolated from the indoor air of work-places of several industry. The isolation rates of Gram positive cocci, Gram positive bacilli, Gram negative bacilli, and Gram negative cocci were 46.3%, 19.8%, 17.3%, and 16.1%, respectively. In Gram positive cocci, the most strains were identified as Aerococcus spp, Micrococcus spp, and Staphylococcus spp. In Gram positive and negative bacilli, and Gram negative cocci were identified as Bacillus spp, Pseudomonas spp, and Neisseria spp, respectively. The frequently isolated fungi were Aspergillus spp, Penicillium spp and Rhizopus spp, respectively. The frequently isolated Aerococcus spp, Micrococcus spp, and Staphylococus spp were highly resistance against ampicillin, erythromycin, methicillin, and tetracycline. These results arouse our attention to microbiologic pollution in the indoor air of work-places of industries.

• 한국수의병리학회지
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• 제7권1호
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• pp.67-69
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• 2003

Three mature layer chickens from a farm in which chickens showed green diarrhea, cyanosis, lethargy, loss of appetite were pathologically examined. Grossly, multiple variable sized caseous nodules were detected in the liver, intestinal serosa and mesentery. In addition, parathypoid nodules in the liver and fibrous serositis on the several peritoneal organs and tissues were noticed. One of spleens had multiple infarction areas. Histologically caseous nodules consisted of central caseous core and peripheral epithelioid cells overlying the fibrous connective tissue. Multinucleated giant cells were scattered between the epithelioid cells and fibrous connective tissue. In these nodules Gram negative cocobacilus bacterial colonies were present, whereas Periodic Schiff reaction and Ziehl-Neelsen stain detected neither fungi nor acid fast bacteria. From these results multiple granulomas might be induced by Escherichia coli. In addition, severe Ascafdiodf and Salmonellosis were coinfected in these chickens.

• 한국미생물·생명공학회지
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• 제21권1호
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• pp.41-46
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• 1993

순수분리된 2,000여 주의 혐기성 세균으로부터 선발된 stain KH-431은 bacteria 및 fungi에 대하여 재현성있는 항균활성을 보이는 물질을 생산하였다. Strain KH-431은 그 형태 및 생리, 생화학적 특성으로 미루어 보아 Clostridium fallax의 근연종으로 동정되었다. strain KH-431의 항생물질 생산을 위한 최적 배양조건에 대해 고찰한 결과 PY배지를 기초배지로 사용하고 sorbitol, yeast extract, d-biotin 그리고 $CaCl_2$를 영양원으로 첨가하였을 때가 양호한 것으로 나타났다. 배지초기 pH 및 배양온도 배양시간에 대한 최적조건은 각각 pH7과 $30^{\circ}C$, 108시간으로 나타났다.20$\ell$ 의 배양액으로부터 solvent extraction, silica gel column chromatography를 거쳐 얻은 sample을 재결정한 결과 KG-431B는 순수한 결정상태로 얻어졌으나 KG-431A의 완전정제에는 많은 문제점이 뒤따른 바 현재 다른 정제방법의 도입을 고려중에 있다.

• Journal of the Korean Wood Science and Technology
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• 제32권2호
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• pp.73-81
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• 2004

저가의 국내산 목재 방미제의 개발을 목적으로 산업부산물인 플루오르화암모늄(NH₄F)으로부터 합성한 6종의 플루오르화합물계 약제를 사용하여 목재에 오염을 일으키는 표면오염균의 생장억제 효과, 소나무, 잣나무 및 라디에타소나무에 대한 목재 방미효력, 목재의 철부식성 및 흡습성에 미치는 영향을 조사하였다. 합성 약제 중에서 주요 성분이 F와 Cu인 RNF-3과 F 단독인 RNF-4가 처리 PDA 배지 및 목재에서 보존 균주의 생장이 전혀 이루어지지 않아 가장 우수한 균의 생장 억제 및 목재 방미효력을 가지고 있는 것으로 밝혀졌다. 이들 약제의 최적 처리 농도는 2%인 것으로 판단되었으며 목재 수종에 따른 방미효력 차이는 거의 나타나지 않았다. 약제 처리 목재는 높은 철부식비를 보였으며 이것은 약제 중에 함유되어 있는 F의 강한 부식성에 기인한 것으로 판단되었다. 그러나 농도 2% 이하의 RNF-3과 RNF-4를 처리한 목재의 철부식비는 무처리와 큰 차이를 보이지 않았다. 또한 합성 약제가 목재 흡습성에 미치는 영향은 없는 것으로 나타났다. 이들 약제의 실용화 검토를 위해서 침엽수 제재목 생산 현장에서의 야외 시험 등 추가적인 연구가 필요할 것으로 사료된다.

• 한국환경과학회지
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• 제14권9호
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• pp.811-815
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• 2005

The activated sludge from the aeration basin of the Su-yeong municipal wastewater treatment plant which has operated by a standard activated sludge process in Busan, Korea was investigated during April 2004 and January 2005 with several bio-indicators. The number of bacteria and fungi per gram of dry weight of MLSS were estimated to be $3.1\times10^6\sim1.5\times10^8\;and\;l.1\times10^3\sim1.1\times10^5$ colony forming units, respectively, by the plate agar method. By cultivation-independent methods, such as 4',6-diamidino-2-phenylindole stain and fluorescence in situ hybridization, the ratio of eubacteria to the entire biomass was evaluated by more than $80\%$ (v/v). The ratio of ammonia-oxidizing bacteria and nitrite-oxidizing bacteria to the total eubacteria was detennined to be $7.0\sim9.8\%\;and\;3.3\sim6.2\%$ without heavy variation in spite of a period of relatively low temperature in the basin. It would be expected that the nitrification would occur or at least co-exist throughout the year in the sludge of many municipal WWTP with influents that contain the sufficient nitrogen sources although the WWTP does not have any specialized processes for the removal of nitrogen.

• Mycobiology
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• 제38권4호
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• pp.286-294
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• 2010

Epicoccum purpurascens stain 5615 AUMC was investigated for its biocontrol activity against root rot disease caused by Pythium irregulare. E. purpurascens greenhouse pathogenicity tests using three leguminous plants indicated that the fungus was nonpathogenic under the test conditions. The germination rate of the three species of legume seeds treated with a E. purpurascens homogenate increased significantly compared with the seeds infested with P. irregulare. No root rot symptoms were observed on seeds treated with E. purpurascens, and seedlings appeared more vigorous when compared with the non-treated control. A significant increase in seedling growth parameters (seedling length and fresh and dry weights) was observed in seedlings treated with E. purpurascens compared to pathogen-treated seedlings. Pre-treating the seeds with the bioagent fungus was more efficient for protecting seeds against the root rot disease caused by P. irregulare than waiting for disease dispersal before intervention. To determine whether E. purpurascens produced known anti-fungal compounds, an acetone extract of the fungus was analyzed by gas chromatography mass spectrometry. The extract revealed a high percentage of the cinnamic acid derivative (trimethylsiloxy) cinnamic acid methyl ester. The E. purpurascens isolate grew more rapidly than the P. irregulare pathogen in a dual culture on potato dextrose agar nutrient medium, although the two fungi grew similarly when cultured separately. This result may indicate antagonism via antibiosis or competition.

• Journal of the Korean Wood Science and Technology
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• 제43권6호
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• pp.798-803
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• 2015

1년간 측정된 개방 및 인접 비개방 전각의 실내 온습도 및 목재 기둥 내측의 표면함수율을 문헌조사를 통해 확인된 목재 가해균류 포자 발아와 생육이 가능한 최소 온습도(최소 습도의 지속기간 포함)와 목재 함수율과 비교하는 간접적인 방법으로 전각 개방이 전각 내부 보존환경에 미치는 영향을 예측하였다. 개방 여부에 관계없이 연중 전각 내부의 온습도 및 목재 함수율 조건은 부후균과 변재변색균의 생육에는 부적절하였으나 장마철이 포함된 여름철 전각 내부의 온습도 및 목재 함수율 조건은 표면오염균의 생육에 적절하였다. 표면오염균 생육을 위한 상대습도 및 목재 함수율 조건, 즉 실내 상대습도가 75% 이상으로 상승한 후 지속되는 기간과 목재 기둥 내측의 표면함수율이 15% 이상으로 상승되는 총 일수를 비교할 때, 전각 내부의 표면오염균 관련 보존환경은 개방 전각이 비개방 전각에 비해 다소 우수하다고 할 수 있다. 오히려 비개방 전각의 경우, 외기 상대습도가 높아지는 여름철에는 전각 내부의 상대습도를 낮추기 위해 문을 개방할 필요가 있다고 사료된다.

• 미생물학회지
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• 제33권1호
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• pp.31-37
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• 1997

Aspergillus niger와 Penicillium chrysogenum간의 lipase 우수 생성 종간 형질전환체를 획득하고, 유전분석을 통하여 다음과 같은 결과를 얻었다. (1) P. chrysogenum의 영양요구물을 확인하여 본 결과 Tyrosine 요구성임을 알 수 있었다. (2) 핵전이를 위한 원형질체 형성 및 재생 조건에서는 Novozym 234의 농도 1%, 삼투안정제는 0.6M KCl, 효소의 처리 시간은 180분 그리고 최적 pH는 5.8로 나타났다. (3) 핵전이에 의한 형질전환의 빈도는 $1.3{\times}$10^{-3}$$ $-3.8{\times}$10^{-3}$$으로 비교적 낮은 편이었다. (4) 유전적 안정성, conidia의 크기, DNA 함량의 측정 그리고 핵염색의 결과 형질전환체의 핵형은 aneuploid로 추정되었다. (5) 형질전환체의 lipase활성은 모균주와 비교하여 1.4-2.2배 증가하였다.

• 한국미생물·생명공학회지
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• 제50권2호
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• pp.245-254
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• 2022

Cellulases are a group of biocatalyst enzymes that are capable of degrading cellulosic biomass present in the natural environment and produced by a large number of microorganisms, including bacteria and fungi, etc. In the current study, we isolated, screened and characterized cellulase-producing bacteria from soil. Three cellulose-degrading species were isolated based on clear zone using Congo red stain on carboxymethyl cellulose (CMC) agar plates. These bacterial isolates, named as HB2, HS5 and HS9, were subsequently characterized by morphological and biochemical tests as well as 16S rRNA gene sequencing. Based on 16S rRNA analysis, the bacterial isolates were identified as Bacillus cerus, Bacillus subtilis and Bacillus stratosphericus. Moreover, for maximum cellulase production, different growth parameters were optimized. Maximum optical density for growth was also noted at pH 7.0 for 48 h for all three isolates. Optical density was high for all three isolates using meat extract as a nitrogen source for 48 h. The pH profile of all three strains was quite similar but the maximum enzyme activity was observed at pH 7.0. Maximum cellulase production by all three bacterial isolates was noted when using lactose as a carbon rather than nitrogen and peptone. Further studies are needed for identification of new isolates in this region having maximum cellulolytic activity. Our findings indicate that this enzyme has various potential industrial applications.