• 한국환경보건학회지
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• 제19권1호
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• pp.30-36
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• 1993

A survey was conducted to measure concentration of airborne microbe in a hospital using RSC air sampler during October~November 1991.The result was as follows: 1) In an agar strip GK-A media for total counts of microbial particles. The highest count were 1384 CFU/m$^3$ in the main lobby, followed by 912 CFU/m$^3$, in the obstetric room, 688 CFU/m$^3$ in 1CU. By gram staining, the distribution for organisms in the air were shown 74.1% in gram possitive cocci followed by 16.8%, in gram possitive bacilli 6.7% in gram negative bacilli and 4.7% in yeast, but low organism was detected in recovery room with 194 CFU/m$^3$. 2) In agar strip S media for Staphylococci the count at the main lobby was detected in the recovery room with 92 CFU/m$^3$, Tests of coagulase were negative Staphylococci with 78%, and positive Staphylococci with 22%. The Staphylococci were highly resistance to penicillin, ampicillin and sensitive to amikacin, cefazolin, gentamycin and chloramphenicol. 3) In agar strip C media for coliform bacteria the colony counts at the main lobby was 139 CFU/m$^3$ and treatment room was 190 CFU/m$^3$, most frequently isolated microorganisms were non fermentative bacilli. 4) In agar strip HS media for yeast and molds. Most frequently colony counts 17~76 CFU/m$^3$, 0.5% lactophenol cotton blue stains were shown unidentified 77.2%, 8.1%, in Penicillium 8.1% in Aspergillus, and 3.8% in mucor.

• 환경위생공학
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• 제23권2호
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• pp.1-18
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• 2008

The tetrachloroethylene (PCE) dehalogenase of Clostridium bifermentans DPH-1 (a halorespiring organism) was purified, cloned, and sequenced. This enzyme is a homodimer with a molecular mass of ca. 70 kDa and exhibits dehalogenation of dichloroethylene isomers along with PCE and trichloroethylene (TCE). Broad range of substrate specificity for chlorinated aliphatic compounds (PCE, TCE, cis-1,2-dichloroethylene, trans-1,2-dichloroethylene, 1,1-dichloroethylene, 1,2-dichloropropene, and 1,1,2-trichloroethane) for this enzyme was also observed. A mixture of propyl iodide and titanium citrate caused a light-reversible inhibition of enzymatic activity suggesting the involvement of a corrinoid cofactor. A partial sequence (81 bp) of the encoding gene for PCE dehalogenase was amplified and sequenced with degenerateprimers designed from the N-terminal sequence (27 amino acid residues). Southern analysis of C. bifermentans genomic DNA using the polymerase chain reaction product as a probe revealed restriction fragment bands. A 5.0 kb ClaI fragment, harboring the relevant gene (designated pceC) was cloned (pDEHAL5) and the complete nucleotide sequence of pceC was determined. The gene showed homology mainly with microbial membrane proteins and no homology with any known dehalogenase, suggesting a distinct PCE dehalogenase. So, C. bifermentans could play some important role in the initial breakdown of PCE and other chlorinated aliphatic compounds in sites contaminated with mixtures of halogenated substances.

• Food Science and Biotechnology
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• 제17권6호
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• pp.1337-1340
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• 2008

The objective of this study was to evaluate the microbial safety of raw beef used to produce Korean beef jerky, The raw beef samples harbored large populations of microorganisms. In particular, psychrophilic bacteria were found to be most numerous ($9.2{\times}10^3-1.0{\times}10^5\;CFU/g$) in the samples. Mesophilic bacteria and anaerobic bacteria were present in average numbers ($10^3-10^5\;CFU/g$). Spore-forming bacteria and coliforms were not detected below detection limit. Yeast and molds were detected at $2.2{\times}10^1-7.8{\times}10^2\;CFU/g$ in the raw beef. Ten samples of raw beef were analyzed for the presence of pathogenic bacteria. Bacillus cereus was isolated from sample B, G, and H. The B. cereus isolates from raw beef samples were identified with 99.8% agreement according to the API CHB 50 kit.

• The Plant Pathology Journal
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• 제34권6호
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• pp.459-469
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• 2018

Plants and microorganisms (microbes) use information from chemicals such as volatile compounds to understand their environments. Proficiency in sensing and responding to these infochemicals increases an organism's ecological competence and ability to survive in competitive environments, particularly with regard to plant-pathogen interactions. Plants and microbes acquired the ability to sense and respond to biogenic volatiles during their evolutionary history. However, these signals can only be interpreted by humans through the use of state-of the-art technologies. Newly-developed tools allow microbe-induced plant volatiles to be detected in a rapid, precise, and non-invasive manner to diagnose plant diseases. Beside disease diagnosis, volatile compounds may also be valuable in improving crop productivity in sustainable agriculture. Bacterial volatile compounds (BVCs) have potential for use as a novel plant growth stimulant or as improver of fertilizer efficiency. BVCs can also elicit plant innate immunity against insect pests and microbial pathogens. Research is needed to expand our knowledge of BVCs and to produce BVC-based formulations that can be used practically in the field. Formulation possibilities include encapsulation and sol-gel matrices, which can be used in attract and kill formulations, chemigation, and seed priming. Exploitation of biogenic volatiles will facilitate the development of smart integrated plant management systems for disease control and productivity improvement.

• Korean Chemical Engineering Research
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• 제52권5호
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• pp.581-586
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• 2014

하수처리장을 운영함에 있어 안정적인 방류수질 확보와 이에 따른 처리 비용을 최소화하는 것이 주요 목적이다. 하지만 유입수 유량 및 성분 농도의 변화와 미생물의 비선형적인 동특성, 기타 환경 요인에 의해서 최적의 운전 제어를 하기가 쉽지 않기 때문에, 기존의 하수처리장에서는 필요한 양 이상의 폭기 및 화학물질을 과량 주입하는 방법 등을 사용하였다. 본 연구에서는 포기조에서 미생물에 필요한 용존산소농도는 유지하면서 과폭기로 인한 전력 비용을 감소하는 최적 제어 방법을 제안하였다. 하수조성와 포기조 미생물의 호흡률은 실시간 미생물 호흡률 측정기(Oxygen uptake rate, OUR)를 이용하여 측정하였고, 실시간 호흡률 측정값을 바탕으로 현재 미생물에 필요한 최적 DO 농도를 제안하였다. 유입수 부하변동에 따라 변화하는 미생물 호흡에 필요한 산소량 만큼만 폭기하도록 구성함으로써, 방류수 수질기준을 만족함과 동시에 전력 비용을 최소화할 수 있는 방안을 제시하였다.

• Applied Biological Chemistry
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• 제24권2호
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• pp.85-93
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• 1981

섬유소(纖維素)를 이용(利用)하기 위한 기초연구(基礎硏究)로서 섬유소분해능(纖維素分解能)이 우수(優秀)한 균주(菌株)를 분리(分離)하여 동정(同定)한 결과(結果) Trichoderma spp.로 추정하였으며 사용된 섬유소 기질(基質)은 볏짚을 용제(溶劑)로 전처리(前處理)한 것과 여기에 산, 가열처리(加熱處理)를 더 가(加)한 것을 사용(使用)하였으며 이 미생물(微生物)에 의(依)하여 전처리 및 산 가열처리(加熱處理)에서 생성되는 섬유소 분해 효소(酵素)를 시험한 결과(結果) 0.1% $H_2SO_4$, $120^{\circ}C$, 한시간동안 처리한 것을 기질(基質)로 하였을 때 효소활성(酵素活性)이 높았다. 또한 pH 5.0, 5일(日) 배양(培養)에서 효소활성(酵素活性)이 증가(增加)하였으며 요소첨가시 20%. 인산칼륨첨가시 21%, 육류추출물첨가시 25%, 감귤피첨가시 19%의 증가(增加)를 나타냈다. 48시간(時間) 효소반응(酵素反應)을 시켰을 때 전처리기질(前處理基質)보다 산(酸), 가열처리기질(加熱處理基質)이 효소활성(酵素活性)이 높았으며 24시간후(時間後)에는 활성(活性)이 완만하였다.

• Journal of Periodontal and Implant Science
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• 제31권4호
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• pp.661-668
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• 2001

P. gingivalis를 단독면역하거나 또는 Fusobacterium nucleatum 선면역 후 P. gingivalis 항혈청을 각각 얻어냈다. 두 종류의 항혈청이 P. gingivalis biofilm을 침투해 들어가는 능력을 confocal laser scanning microscope를 이용하여 비교 감증하였다. 항혈청의 P. gingivalis에 대한 avidity index도 측정하였다. 결과적으로 F. nucleatum의 선면역은 P. gingivalis 특이 항혈청에 대해 세균성 biofilm의 침투능력을 저하시키고, 동일한 세균에 대한 avidity도 감소시켰다.

• Applied Biological Chemistry
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• 제26권1호
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• pp.35-40
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• 1983

김치에 분리한 젖산균 20주(株)의 Escherichia coli, Staphylococcus aureus 등 5종의 Test organism에 대한 생육저해실험 결과 가장 생육저해능력이 큰 A7 (Pediococcus cerevisiae)와 C4 (Leuconostoc spp.)를 선발하였다. 이 두 균주를 각각 Escherichia coli와 동시에 접종하여 배양한 결과 초기부터 Escherichia coli의 생육을 억제하였으며 약 24시간 후부터는 Escherichia coli의 균수가 급격히 감소하였다. Staphylococcus aureus와 Bacillus cereus에 대하여도 .대체로 비슷한 생육억제작용을 나타내었다. 세가지 Test organism 모두 A7과 배양할 경우 C4의 경우보다 더 큰 death rate constant를 나타내었다 이 혼합 배양액에 catalase를 첨가한 경우 생육저해현상에 영향이 없었으므로 이 두 균주의 생육억계작용은 $H_2O_2$ 생성과 관련이 없는 것으로 나타났다. A7의 배양 여액만을 Escherichia coli 배양액에 첨가한 경우에도 A7균주의 혼합 배양과 동일한 생육저해 현상을 보였으나 여액을 $80^{\circ}C$에서 30분간 열처리후 가하였을 때는 생육저해작용이 거의 나타나지 않을 뿐 아니라 여액에 trypsin 처리한 경우에도 생육저해작용은 크게 억제되었다. 이상의 결과로 A7 균주의 생육저해작용은 단백질류 생육저해물질의 생산에 의한 것이라고 추정할 수 있다.

• Asian-Australasian Journal of Animal Sciences
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• 제22권8호
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• pp.1202-1208
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• 2009

Synbiotics is the term used for a mixture of probiotics (live microbial feed additives that beneficially affects the host animal) and prebiotics (non-digestible food ingredients that beneficially affect the organism). This study investigated the effect of probiotics from anaerobic microflora with prebiotics on growth performance, nutrient digestibility, noxious gas emission and fecal microbial population in weaning pigs. 150 pigs with an initial BW of 6.80${\pm}$0.32 kg (20 d of age) were randomly assigned to 5 dietary treatments as follows: i) US, basal diet+0.15% antibiotics (0.05% oxytetracycline 200 and 0.10% tiamulin 38 g), ii) BS, basal diet+0.2% synbiotics (probiotics from bacteria), iii) YS, basal diet+0.2% synbiotics (probiotics from yeast), iv) MS, basal diet+0.2% synbiotics (probiotics from mold), v) CS, basal diet+0.2% synbiotics (from compounds of bacteria, yeast and mold). The probiotics were contained in $10^{9}$ cfu/ml, $10^{5}$ cfu/ml and $10^{3}$ tfu/ml of bacteria, yeast and molds, respectively. The same prebiotics (mannan oligosaccharide, lactose, sodium acetate and ammonium citrate) was used for all the synbiotics. Pigs were housed individually for a 16-day experimental period. Growth performance showed no significant difference between antibiotic treatments and synbiotics-added treatments. The BS treatment showed higher (p<0.05) dry matter (DM) and nitrogen digestibility while ether extract and crude fiber digestibility were not affected by the dietary treatment. Also, the BS treatment decreased (p<0.05) fecal ammonia and amine gas emissions. Hydrogen sulfide concentration was also decreased (p<0.05) in BS, YS and MS treatments compared to other treatments. Moreover, all the synbioticsadded treatments increased fecal acetic acid concentration while the CS treatment had lower propionic acid concentration than the US treatment (p<0.05) gas emissions but decreased in fecal propionate gas emissions. Total fecal bacteria and Escherichia coli populations did not differ significantly among the treatments, while the Shigella counts were decreased (p<0.05) in synbiotics-included treatment. Fecal bacteria population was higher in the YS treatment than other treatments (p<0.05). The BS treatment had higher yeast concentration than YS, MS and CS treatments, while US treatment had higher mold concentrations than MS treatment (p<0.05). Therefore, the results of the present study suggest that synbiotics are as effective as antibiotics on growth performance, nutrient digestibility and fecal microflora composition in weaning pigs. Additionally, synbiotics from anaerobic microflora can decrease fecal noxious gas emission and synbiotics can substitute for antibiotics in weaning pigs.

• 생명과학회지
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• 제25권6호
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• pp.715-723
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• 2015

지구상에 존재하는 전체 동물 중 가장 큰 부분을 차지 하고 있는 곤충은 예로부터 인간의 식품, 농업, 산업, 의약 등의 일상 생활에 이용되어 왔다. 많은 수와 높은 영양학적 가치로 곤충의 생리활성물질이 미개발 생물자원으로 재평가 되고 있다. 곤충은 면역세포, 곤충 혈구세포, 효소들의 연쇄반응 혹은 항균 단백질/펩타이드 같은 방법으로 외부의 감염에 저항성을 가지게 된다. 항균 펩타이드는 곤충의 혈림프의 선천성 면역 시스템 중 주요한 성분중의 하나로 항생제 내성 균주의 출몰이 빈번하게 일어나 해결책으로 새로운 항생제 개발이 시급한 시점에서 유력한 후보물질로 주목 받고 있다. 곤충 유래 항균 펩타이드는 150개가 넘게 분리되었으며 크게 세크로핀, 디펜신, 글라이신/프롤린이 풍부한 펩타이드로 이루어진다. 이 논문에서, 향균 펩타이드를 생산하는 여러 곤충 중에서 벌, 소똥구리, 울도하늘소, 나비 그리고 울도하늘소에서 얻을 수 있는 펩타이드의 종류 그리고 작용 기작에 대해 알아보았다. 이 펩타이드들은 항균효과를 가지고 있으며 멜리틴을 제외하고 적혈구의 용혈 현상이 나타나지 않고 주로 세포막을 붕괴시키거나 세포자살기작을 유도하여 병원성 미생물의 성장을 억제한다. 곤충 유래 펩타이드와 같은 생리활성물질이 그 활용 가능성의 면에서 엄청난 가능성을 가지고 있어 이에 대한 연구는 앞으로 더 주목을 받을 것이다.