• Journal of Microbiology and Biotechnology
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• v.22 no.3
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• pp.283-291
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• 2012

Bioremediation efforts often rely on the application of surfactants to enhance hydrocarbon bioavailability. However, synthetic surfactants can sometimes be toxic to degrading microorganisms, thus reducing the clearance rate of the pollutant. Therefore, surfactant-resistant bacteria can be an important tool for bioremediation efforts of hydrophobic pollutants, circumventing the toxicity of synthetic surfactants that often delay microbial bioremediation of these contaminants. In this study, we screened a natural surfactant-rich compartment, the estuarine surface microlayer (SML), for cultivable surfactant-resistant bacteria using selective cultures of sodium dodecyl sulfate (SDS) and cetyl trimethylammonium bromide (CTAB). Resistance to surfactants was evaluated by colony counts in solid media amended with critical micelle concentrations (CMC) of either surfactants, in comparison with non-amended controls. Selective cultures for surfactant-resistant bacteria were prepared in mineral medium also containing CMC concentrations of either CTAB or SDS. The surfactantresistant isolates obtained were tested by PCR for the Pseudomonas genus marker gacA gene and for the naphthalene-dioxygenase-encoding gene ndo. Isolates were also screened for biosurfactant production by the atomized oil assay. A high proportion of culturable bacterioneuston was tolerant to CMC concentrations of SDS or CTAB. The gacA-targeted PCR revealed that 64% of the isolates were Pseudomonads. Biosurfactant production in solid medium was detected in 9.4% of tested isolates, all affiliated with genus Pseudomonas. This study shows that the SML is a potential source of surfactant-resistant and biosurfactant-producing bacteria in which Pseudomonads emerge as a relevant group.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 1999.10a
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• pp.63.2-63
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• 1999

• Journal of Applied Biological Chemistry
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• v.48 no.4
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• pp.161-166
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• 2005

Among 24 isolates of fluorescent Pseudomonads, 5 isolates named as LPT1, LPT2, LPT3, LPT4 and LPT5 were screened in vitro for their nematicidal activity against cyst forming nematode, Heterodera cajani causing patchiness, poor and stunting growth besides discoloration in Sesamum indicum. Second stage juveniles of H. cajani hatched from egg masses were collected from roots of host plant and subjected to fresh and heat-treated culture filtrate of isolates for 24 h. Mortality of H. cajani was recorded on the basis of parameters used for test organism bioassay. Among these isolates, Pseudomonas aeruginosa LPT5 caused maximum mortality towards second stage juvenile of H. cajani in vitro. Five isolates were used as seed coating for the management of cyst forming nematode H. cajani on sesame in green house condition. The strains LPT5 was better than the other strains in reducing the population of H. cajani both in vitro and in vivo. The reduction in cyst and juveniles population was found to be 49 and 60%, respectively when seeds were coated with strain LPT5. Among other strains, LPT4 was also found to inhibit the cyst and juveniles population 12 and 36% respectively. Increases in early vegetative plant growth parameters recorded in both in vitro and in vivo further revealed the significance of indigenous bacteria in comparison to introduced strain.

• The Plant Pathology Journal
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• v.28 no.1
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• pp.1-9
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• 2012

In this study, 200 isolates of fluorescent pseudomonads were isolated from different fields of East and West Azarbaijan and Ardebil provinces of Iran. These bacterial isolates were screened on the basis of a dual culture assay, the presence of known antibiotic genes, and their ability to successfully colonize roots and to promote plant growth. Twelve isolates exhibited 30% or more inhibition of mycelia growth of $P.$ $drechsleri$. Genes encoding production of the antibiotics 2,4-diacetylphloroglucinol, phenazine-1-carboxylic acid, and pyoluteorin were detected in some strains but none of the strains possessed the coding gene for production of antibiotic pyrrolnitrin. In an $in$ $vitro$ test for root colonization, the population density on roots of plants treated with most of the above strains was more than 6 $\log_{10}$ CFU $g^{-1}$ roots, with a maximum of 7.99 $\log_{10}$ CFU $g^{-1}$ roots for strain 58A. Most of the strains promoted significant plant growth in comparison to non-treated controls. In green house studies, the percentage of healthy plants in pots treated with strains 58A and 8B was 90.8% and 88.7%, respectively. The difference between these treatments and treatment with the fungicide metalaxyl was not significant.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2005.04a
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• pp.68.2-68.2
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• 2005

• Journal of the korean veterinary medical association
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• v.33 no.4
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• pp.222-234
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• 1997

유질은 성분과 위생상태로 결정되어 진다. 질/위생은 사람건강 보호와 적정소비에 대한 관점에서 보면 장점인 영양적 중요성에서 오는 욕망을 이르키는 성질과 일정범위의 좋은점 사이에 원유변화와 만나게되는 것이 필요하다. 높은 질/위생적 원유에 대한 가치의 주요 평가는 : - 부패미 생물의 낮은 수 - 유방염 병원성균이 포함된 병원성군이 없거나 대단히 낮은 수 - 가능한 한 멀리 피할 것은 잔류와 오염 그리고 또는 최고잔류한계(Maximum Residue linits. )이하를 지킬 것. 우유내 부패세균은 다음 군에서 주요 우유성분에 대한 공격의 그들 주요점에 의하여 세분할 수 있다. - 당분해(Glycolytes) - Streptococci, lactobacill; - 단백질 분해(Proteolytes) - Pseudomonads, Enterobacteriaceae, Aerobic sporeformer - 지방분해(Lipolytes) - Pseudomonads, Micncocci, Aeromonads, Coryneb acteria 원유내 부패세균의 존재와 분열은 우유성분 변화와 생산품의 질에 영향을 줄 것이다. 더구나 원유의 맛은 역의 영향이 될 것이며 열 안정성 세균성 효소는 생산품에서 계속적으로 작용된다. 특히 오랜 저장시에 그러하다. 그리고 안정성, cream의 맛과 UHT 우유에 나쁜 영향을 준다. 이 병원성 세균을 고전적 미생물과 최근 발견된 미생물이 포함된다. 현재는 Salmonella, 병원성 E. Coli 균주, Listeria monocytogenes, Campylobacter Jejuni, Yersinia enterocolitica, Staphylococcm aureu는 대단히 중요하다. 원유의 세균학적 질과 지불제도에 대한 법적요구는 우유위생지침 92/94 EEC와 IDF설문 2893/A(전문가모임 A8군)의 결과를 기준으로 설명되었다. IDF Nr. 305/1995는 농장 지불제도에 관한 정보가92/93년 동안 IDF국가들 사이 차이나는 실제적 위치가 실려있다. 지불제도의 차이나는 현상은 보고의 초점과 연관 유질, 위생적 질, 우유시료채취, 수집방법론 그리고 여러가지 지불공식과 관계된 조사는 논쟁이 있었다. 현재 있는 자료를 제시한 몇 나라는 1992년에 응용한 것이고, 기타는 그후 응답으로 1993년과 1994년에 있던 것이 제시되었다. 식품위생에서 법적인 요구는 HACCP제도가 더욱더 추가로 포함된다. 더우기 위험분석은 위생과 질에 관련시켜 모든 연결결정에 대하여는 과학적 근거가 있어야 한다.

• Korean Journal of Microbiology
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• v.10 no.4
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• pp.175-190
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• 1972

This work was designed to illustrate physiological effects on the elimination of sulfur and its compounds in petroleum using sulfur-reducing bacteria. Deulfurizing bacteria were collected from sewage and soil at several areas in Soul and Ulsan, Korea. Seven supecies of sulfur-reducing microbes isolated were identified as : Pseudomonas marginata, Ps.effusa, Ps. putrefaciens, Ps.pseudcmcnelli, Ps. xanthochlora, Ps.bowlesiae, and Ps.aeruginosa. And some experiments were performed to define the growing characteristics of the Pseudomonads and the results obtained are as follows : 1) Shaking culture method was more effective for the growth of the cells than stagnant culture. 2) Beef peptone medium was better for the growth than other media. 3) Cuprous chloride of 50 ppm and cupper sulfate of 300 ppm treated, respectively, in the medium were effective for the growth. 4) Benzene of toluene of 5,000 ppm and petroleum ether of 50,000 ppm did not show remarkable inhibitory effects on the growth.

• Applied Biological Chemistry
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• v.48 no.3
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• pp.296-300
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• 2005

Among the root colonizing and plant growth promoting bacteria isolated from the bacterial wilt suppressive soil, five strains were detected to produce siderophores by CAS agar assay. The most effective isolate, TS3-7 strain induced significant suppression of bacterial wilt disease in tomato and pepper plants. Seed treatment followed by soil drench application with this strain resulted in over 80% reduction of bacterial wilt disease compared with the control. Significant disease suppression by TS3-7 strain was related to the production of siderophore. Besides iron competition, induction of resistance of the host plant with siderophore was suggested to be another mode of action that suppress bacterial wilt, based on the lack of direct antibiosis against pathogen in vitro. According to Bergey's Manual of Systemic Bacteriology and 16S rDNA sequence data, TS3-7 stain was identified as Pseudomonas sp. TS3-7.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.340-343
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• 2003

Soils contaminated by hazardous hydrophobic organic compounds, such as polycyclic aromatic hydrocarbons (PAHs), have become a major environmental issue due to toxic and carcinogenic properties of those compounds. In this work, we investigated effects of various metabolic inducers on phenanthrene biodegradation. Biodegradation tests were peformed with two different Pseudomonads: Pseudononrdia hydrocarboxydans (Gram positive) and Pseudomonas putida (Gram negative). Intermediates of phenanthrene metabolism (1-hydroxy-2-naphthoate, salicylate, catechol, phthalate and protocatechuate) were selected as inducers. The tests indicated that 1-hydroxy-2-naphthoate was the most effective inducer and enhanced the phenanthrene degradation rate up to 5.7 times, even though all the others also had induction ability to some extent. The effective induction could be achieved even at a low concentration of 1-hydroxy-2-naphthoate. Addition of metabolic inducers would be an attractive trick for the successful bioremediation of PAH-contaminated soil.

• Korean Journal of Environmental Agriculture
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• v.17 no.3
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• pp.220-226
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• 1998

The effects of metalaxyl(granule), carbofuran(granule) and simazine(water soluble powder) on the soil microflora were conducted at field soil between Iksan and Chonju province. Pesticides were divided into 0.5, 1, 1.5 and 2.0 times of normal of field, respectively. The number of fluorescent Pseudomonas was ranged from $10^3$ to $10^6/g$ in both field soil treated with cabofuran. Pseudomonas concentration of Chonju field soil slowly increased and approached the maximum level at 56 day after treatment(DAT). It showed the higher at 14DAT than other DAT in Iksan field soil treated with metalaxyl or simazine, whereas it increased again at 112 DAT in metalaxyl treatment. Cabofuran treatment of both field soil showed maximum Pseudomonas number at 28 DAT compared to that of other treatments. In Chonju field soil, those Pseudomonads of metalaxyl and simazine treatment increased the highest level at 7 DAT. Simazine treatment decreased it's number from the beginning of experiment. In both soil, metalaxyl treatment decrease the general fungi number at 7 DAT, but increase at 14 and 56 DAT in Iksan field soil. However it increased at 56 DAT in Chonju field soil. Cabofuran treatment of Iksan field soil tended to decrease general fungi number at 28 DAT, but was ranged from 1.0 to $8.6{\times}104/g$ for the rest of experimental period. It started to increase at 56 DAT simazine treatment of Iksan. General bacterial concentration both soil treated with cabofuran was belong to $26.6{\sim}29.6{\times}106$. It was the highest at 56 DAT, but was not significantly different. General actinomyces number was highly increased at 7 and 112 DAT compared to that of other DAT. Pseudomonas putida or P. fluorescens from both field soil was separated and identified 10 to 30 of all 104 Pseudomonas, respectively. All isolated microorganisms showed chemical resistance of 100ppm metalaxyl, cabofuran and simazine treatment.