• 한국토양비료학회지
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• 제45권5호
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• pp.792-797
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• 2012

경남지역 논토양의 글로말린 함량과 미생물 특성과의 관계를 분석하기 위하여 2011년에 20개소를 선정하여 분석한 결과는 다음과 같다. 토양 글로말린 함량은 토양 유기물 함량 (r=0.595, p<0.01) 및 탈수소효소 활성 (r=0.663, p<0.01)과 정의상관 관계를 나타냈다. 또한, 글로말린 함량은 미생물 생체 탄소 함량 (r=0.710, p<0.001) 및 총 세균군집 (r=0.616, p<0.01)과 정의상관을 보였다. 그리고 글로말린 함량은 그람음성 세균의 군집 (r=0.561, p<0.05) 및 cy19:0/18:$1{\omega}7c$ (r=0.487, p<0.05)와 정의상관 관계를 나타냈다. 따라서 논토양에서 글로말린 함량은 지속가능한 친환경농업을 위해 토양 건강성의 지표로 활용할 수 있을 것으로 생각된다.

• 한국환경보건학회지
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• 제38권6호
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• pp.520-528
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• 2012

Objective: This study was performed to assess bacterial distribution concerned in sanitation management of public lavatory in Seoul. Methods: In this research, bacteriological investigation on public lavatory was accomplished for bidet water, bidet nozzle, washbowl and lavatory stool in the 50 public facilities such as public institutions, subway stations, cinema, department stores, large-scale buildings and hospitals amount to 374 specimens. Results: The geometric mean of colony forming unit(CFU) in total aerobic colony count were analyzed as follows; $5.2{\times}10^2/100cm^2$ on lavatory stool, $7.2{\times}10^3/ea$ on bidet nozzle, $7.8{\times}10^3/ea$ on center ring of washbowl, $1.4{\times}10/mL$ in bidet water (ml) and 7.0/ea on doorknob. Opportunistically pathogenic germs such as Staphylococcus aureus, Escherichia coli, Enterobacter cloacae, Pseudomonas aeruginosa were isolated in 3.7%, 5.9%, 3.2% and 1.9% of total specimens, respectively. Conclusion: The result of this study shows that there were some facilities where the pathogenic germs were detected to may cause urological infection. And the CFU of general bacteria as the representative indicator of disinfection and lavatory cleaning were high enough to imply the improvement of sanitation management of public lavatories should be contrived.

• Asian-Australasian Journal of Animal Sciences
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• 제12권2호
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• pp.180-185
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• 1999

Effects of host immunization on bacterial translocation and growth performance in weanling piglets were studied. Twenty four barrows were assigned to one of two immunization treatments: Control group (CON: immunized with placebo) or Immunization group [IMMU: immunized with Antigen cocktail; Keyhole limpet hemocyanin (KLH), Ovalbumin (OA), and Tetanus toxoid (TT)]. On d0, piglets were weaned and intramuscularly immunized with 2 ml of placebo or Antigen cocktail, respectively. Antigen-specific Ig titers were determined by ELISA (Enzyme Linked ImmunoSorbent Assay). Ig titers to E. coli-derived lipopolysaccharides (LPS) were measured as the indicator of bacterial translocation. Ig titers to LPS were higher (p<0.10, 0.05 or 0.01) in CON group before immunization (d0), but the difference disappeared with time and IgA titers to LPS became higher (p<0.05) in IMMU group on d39. In IMMU group, IgG titers to LPS from d28 onwards showed positive correlations (p<0.10, 0.05, 0.01 or 0.001) with IgG titers to KLH from d11 onwards and with IgM titers to KLH from d7 onwards. Generally, growth performance was negatively related to IgG titers to LPS. Average daily gain for d28 to d35 showed negative correlations (p<0.10, 0.05, or 0.01) with IgG titers to LPS on d28 onwards in immunization group. These results reveal some evidences that host immunization might facilitate bacterial translocation and high humoral immune responses to LPS are negatively related with the growth performance.

• 한국수산과학회지
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• 제51권1호
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• pp.8-14
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• 2018

We investigated the levels of microbial contaminants and microbial hazards during dried-laver processing. We analyzed 321 samples obtained from 18 dried-laver Pyropia spp. manufacturing facilities, including water, swab-, and processing samples as well as final products. The levels of microbial contaminants, including viable cell counts (VCC) and coliform bacteria, increased as processing progressed. The sanitary indicator bacterium, Escherichia coli, was not detected in the final products although VCC levels were high, generally exceeding 5 log CFU/g. We also investigated changes in microbial contaminants at each processing step. Both VCC and total coliform dramatically increased after 4 days of continuous processing, indicating that microbial contaminants originated, mainly, from cross contamination during processing.

• 한국축산식품학회지
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• 제32권5호
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• pp.598-603
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• 2012

Beef qualities which can be properly predicted by time-temperature integrator (TTI), a chromatic indicator, were selected in terms of its similarity of temperature dependence between beef qualities and TTI, denoted by Arrhenius activation energy ($E_a$). The high similarity is required to afford accurate prediction. A devised enzymatic TTI based on laccase (an oxidase), which catalyses the oxidation on 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) producing color development, was applied. The factors of beef quality, such as volatile basic nitrogen (VBN), pH, color (CIE $L^*$, $a^*$), Warner-Bratzler shear force (WBSF), Pseudomonas spp. count, and lactic acid bacteria (LAB) count were considered for the selection. $E_a$ (55.48 kJ/mol) of the TTI was found to be similar to those of the beef qualities (all referred) in the order of LAB count (53.54 kJ/mol), CIE $a^*$ value (61.86 kJ/mol), pH (65.51 kJ/mol), Pseudomonas spp. Count (44.54 kJ/mol), VBN (67.98 kJ/mol), WBSF (40.67 kJ/mol), and CIE $L^*$ value (33.72 kJ/mol). The beef qualities with more similar $E_a$ to that of the TTI showed less difference between real and TTI predicted levels. In conclusion, it was found out that when applying TTI to food packages, their $E_a$ similarity should be checked to assure accurate estimation of food quality levels from TTI response.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2010년도 정기총회 및 추계학술발표회
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• pp.17-17
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• 2010

Rhizobacteria are a diverse group of free-living soil bacteria that live in plant rhizosphere and colonized the root system. Plant growth-promoting rhizobacteria (PGPR) possessing ACC deaminase (ACCD) can reduce ACC and ethylene in plant tissue and mediated the growth of plants under various stresses including salt stress. ACCD decrease ethylene levels in plant tissue that produce high levels of ethylene in tissue via elevated levels of ACC under salt stress. We selected strains of Pseudomonas sp. possessing ACCD activity for their ability to promote plant growth under salt stress from soil sample collected at Byeonsan, Jeonbuk, South Korea. The Pseudomonas strains possessing ACCD increased the rate of the seedling and growth of chinese cabbage seeds under salt stress. We cloned ACCD gene from P.fluorescens and expressed recombinant protein in Escherichia coli. The active form of recombinant ACCD converted ACC to a-ketobutyrate. The in vivo treatment of recombinant ACCD itself increase the rate of the seedling and growth of Chinese cabbage seeds under salt stress. The polyclonal P.fluorescens anti-ACCD antibody specifically reacted with ACCD originated from Pseudomonas. This indicates that the antibody might act as an important indicator for ACCD driven from Pseudomonas exhibiting plant growth-promoting activity. This study will be useful for identification of newly isolated PGPR containing ACCD and exploioting the ACCD activity from PGPR against various biotic and abiotic stresses.

• 미생물학회지
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• 제55권3호
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• pp.220-225
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• 2019

최근 10년간 미생물생태분석 기반의 연구는 차세대염기서열분석법이 개발된 이래로 지속적으로 증가하고 있다. 장내미생물생태와 건강의 연관성은 미생물 생태학 분야에 있어서 중요한 결과로 여겨지고 있다. 미생물 군집 분석은 주로 16S rRNA 유전자 가변 영역의 염기서열을 통해 분석되지만 이는 미생물의 활성 정보를 제공하지 않는다. 본 연구에서는 cDNA 기반의 미생물 생태분석을 수행하고 DNA 및 cDNA기반의 미생물생태분석 결과를 비교하였다. 두 가지의 서로 다른 접근법이 Butyrate producer와 probiotics와 같이 장내 대사과정에서 중요한 미생물의 abundance 뿐만 아니라 비만 지표로 알려진 Firmicutes 와 Bacteroidetes의 비율에 있어서 차이가 있음을 나타내었다. 따라서, cDNA 기반 미생물 군집은 이전에 수행된 DNA 기반 미생물 군집 분석과 비교하여 장내미생물생태의 역할과 관련된 또 다른 분석 방향성을 제공한다.

• Journal of Applied Biological Chemistry
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• 제62권3호
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• pp.247-250
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• 2019

Wheat is one of the most important grains. Its consumption is increasing globally. Many countries are making efforts to increase the extent of wheat harvest. It is known that plant growth promoting rhizobacteria (PGPRs) have beneficial effects on various plants. Two PGPRs including Paenibacillus pabuli strain P7S (PP7S) and Pseudomonas nitroreducens strain IHB (PnIHB) were employed to investigate effects of PGPRs on early growth of three wheat cultivars (Koso, Seakumkang, and Jokyung). While PP7S had adverse effects on Seakumkang and Jokyung, PP7S had positive effects on Koso except root length compared to control group having no treatment of PP7S. However, all treatments with PnIHB had adverse effects on germination rate, root/shoot lengths, vigor index, and dry root/shoot weights of all three wheat cultivars. These positive effects with PP7S on Koso might be related to the earlier emergence of wheat seed above soil which is known to be an indicator of increased yield. Results of the present study suggest that if proper PGPR strains are selected, they could have positive effects on early growth rate of a wheat cultivar.

• The Plant Pathology Journal
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• 제35권3호
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• pp.234-242
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• 2019

Thirty-four strains of bacteria were isolated from Phellodendron amurense. Using Nectria haematococca as an indicator strain, the best strain, B18, was obtained by the growth rate method. The morphological, physiological and biochemical characteristics of strain B18 and its 16S DNA gene sequence were identified, and the biocontrol effect of strain B18 was assessed in pot and field tests, as well as in a field-control test. Drilling methods were used to determine the antibacterial activity of metabolites from strain B18 and their effects on the growth of pathogen mycelia and spores. The best bacteriostatic rate was 85.4%. B18 can hydrolyse starch and oxidize glucose but does not produce gas; a positive result was obtained in a gelatine liquefaction test. According to 16S DNA gene sequencing, strain B18 is Bacillus methylotrophicus (GenBank accession number: MG457759). The results of pot and field-control trials showed 98% disease control when inoculating $10^8cfu/ml$ of the strain. The disease control effect of the B18 culture liquid (concentrations of $10^8$, $2{\times}10^6$, $10^6$, $5{\times}10^5$ and $2.5{\times}10^5cfu/ml$) in the field-control test was higher than 80%, and the cure rate of the original delivery solution was 96%. Therefore, in the practical forestry production, a $2.5{\times}10^5cfu/ml$ culture liquidshould be applied in advance to achieve good control effects.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2017년도 학술발표회
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• pp.94-94
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• 2017

지속적인 수질의 모니터링과 관리가 어려운 개발도상국의 경우, 모델링을 통한 병원균의 예측이 중요하다. Soil and Water Assessment Tool (SWAT)은 유역 모델로 병원균의 거동을 모의하는데 널리 활용된다. 하지만 SWAT이 모의하는 in-stream 모듈의 경우, 소멸, 부유, 퇴적의 단계만을 고려하여 정확도가 부족하다. 따라서 본 연구는 기존 모듈에 hyporheic exchange와 생장 단계를 추가하여 모듈의 성능 개선 및 열대 산지 유역에서의 병원균의 거동을 모의하였다. 본 연구는 몬순 기후 및 산지 지형을 가진 라오스의 Houay Pano 유역을 대상으로 대장균 (Escheichia coli, E.coli)의 거동을 2011년부터 2013년까지 일 단위로 모의하였다. 기존의 SWAT 박테리아 모듈의 경우, 소멸 단계만을 가지고 보정하였을 때 모델은 대부분 0의 값을 가졌고, 부유 및 퇴적 단계가 추가 된 후에는 우기시 대부분의 모델값이 관측값의 95% 신뢰 구간에 포함되었으나 건기에는 농도가 여전히 낮게 모의됨을 확인 할 수 있다. 건기 시 낮게 모의된 농도를 증가시키기 위해, 온도에 따른 생장 단계를 추가하였으며, 이때 생장 속도는 설정된 최소-최대 생장 온도 사이에서 최대값을 가진다. 하지만 온도에 따른 생장은 열대 기후의 특성상 전 기간에 걸쳐 동시에 증가하여 건기에만 낮게 모의된 농도를 보완하는 데는 한계가 있었다. Hyporheic exchange는 강바닥에 임시로 저장된 박테리아의 양이 특정 유량에 의해서 수계로 유입되는 현상으로, 본 연구에서는 일정한 양의 hyporheic flow를 가정하여 모의하였다. 결과적으로 Hyporheic exchange를 통해 유입되는 적은 양의 E.coli는 기존에 타당하게 모의된 우기의 농도는 그대로 유지하되, 건기에 낮게 모의된 농도는 증가시켜 기존 SWAT 모듈의 한계점을 잘 보완한 것을 확인 하였다. 결론적으로, 기존의 SWAT 모델은 건기 시 낮은 농도의 E.coli를 모의하기에 한계를 보였으며, 전 기간에 걸쳐 높은 온도를 유지하는 열대 기후에서 생장 단계는 이러한 한계를 보완하기에 적합하지 않은 것으로 판단되었다. 그러나 적은 양이 전 기간에 걸쳐 동일하게 유입되는 hyporheic exchange의 경우, 건기에 낮게 모의된 농도를 증가시켜 기존의 한계를 보완할 수 있었다.