The aim of this study was to isolate and identify marine bacterium with anti-methicillinresistant Staphylococcus aureus (MRSA) activity, and to purify the anti-MRSA compound, as well as to determine its activity and synergistic effects. Among the marine bacteria isolated in this study, the YJ-1 isolate had the strongest anti-MRSA activity. The YJ-1 isolate was identified on the basis of its biochemical characteristics and an analysis of 16S rRNA gene sequences. The YJ-1 isolate showed over 99.2% homology with Pseudomonas stutzeri, and was designated as a Pseudomonas sp. YJ-1. The optimal culture conditions were 25℃ and initial pH 7.0. For the purification of the anti-MRSA compounds, the YJ-1 was cultured in Pa PES-II medium, and the culture filtrates were extracted by ethyl acetate, hexane, and 80% MeOH. The 80% MeOH fraction was separated by a C18 ODS column, silica gel chromatography and a reverse phase HPLC, to yield three anti-MRSA agents, the MR1, MR2, and MR3 compounds. When the MR1 compound of 250 μg mL-1 concentration was applied to the MRSA cells, over 95% of bacterial cells was killed within 48 hr. Compared with vancomycin and ampicillin, the MR1 compound showed significant anti-MRSA activity. In addition, the anti-MRSA activity was increased by dose and time dependent manners. Furthermore, the combination of an MR1 compound with vancomycin produced a more rapid decrease in the MRSA cells than did the MR1 compound alone. Taken together, our results suggest that the Pseudomonas sp. YJ-1 and its anti-MRSA compounds could be employed as a natural antibacterial agent in MRSA infections.

We experimented to see if the tolerance of Agaricus bisporus to Pseudomonas sp. causing the bacterial brown blotch disease which is causing great damage in the button mushroom cultivation was inherited. There was no correlation between mycelial growth rate and mushroom tolerance to pathogens at each temperature. In the mycelial stage, the strains tolerance to Pseudomonas sp. were not as strong as those of their parents, but they were generally stronger or more tolerance than those of weaker strain (ASI1321). In fruiting body, tolerance was decreased compared to mycelial. In fruiting body, later generations of two strains had similar tolerance, unlike strong or weak tolerance of parental generation. Therefore, browning of fruit body is thought to be caused not only by tolerance but also by various other factors. Especially, the future generation of the strains which were tolerance to Pseudomonas sp. were very weak in the mycelial stage, indicating that the tolerance of the parental generation was inherited to the later generations. The damage of each pathogen was different in mycelium and fruiting body. P. tolaasii caused higher browning than P. agarici in fruit body. P. reactans did not have a significant effect on the mycelium but affected the browning of the fruit bodies. P. agarici had higher mycelial growth inhibitory ability than fruiting body.

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 30o, 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% NaNO3, 0.5% KH2PO4, and 1.5% asparagine.

버섯 세균갈성색무늬병원균인 Pseudomonas tolaasii에대한 독소저해균으로 보고된 Pseudomonas sp. HC1 균주의 배양적 특성과 최적 배양을 위한 대량배지를 선발하였다. CH1균주의 생육온도는 20~40oC, pH는 5.0~11.0까지넓은 범위에서 왕성한 생육을 보였다. 대량배양을 위한효율적인 영양원 선발을 위하여 기본배지에 탄소원fructose 등 18종, 무기질소원 NH4Cl 등 6종, 유기질소원peptone 등 6종 그리고 아미노산 asparagine 등 11종을 각각 1%씩 첨가하였고, 무기염류 13종을 1mM 농도로 첨가하여 각각에 대한 생육에 미치는 영향을 조사하였다.또한 선발된 각각의 영양성분들에 대한 최적 농도를 조사하기 위하여 각각의 성분을 0.1%에서 4.0%까지 배지에첨가하여 배양후 생육정도를 조사하였다. 그 결과, 대량배양을 위한 생육최적조건은 온도 20oC, pH5, 탄소원 0.9%dextrine, 유기질소원 1.5% yeast extract, 무기질소원0.5% (NH4)2HPO4, 아미노산 3.0% cysteine, 무기염류4mM FeCl3에서 왕성한 생육을 보였다.

고온기 분식 칼랑코에 재배에 있어 문제는 고온 스트레서에 의한 생장의 억제로, 본 연구는 지하부 및 지상부의 생장을 촉진을 시킬 수 있다고 알려진 근권 생장촉진미생물(Pseudomonas sp. B와 Pseudomonas sp. D2)을 선발하여 사용하였으며 천연물로서는 alginoligosaccharide와 glucosamine oligosaccharide를 사용하였다. 또한 이들의 AG-용액과 단일 및 복합 처리하여 재배 온도차이를 부여한 경우 칼랑코에의 생장에 미치는 영향을 조사하였다. 상이한 지하부 온도조건은 25℃, 30℃ 및 35℃로 처리하여, 2주후 초장, 엽장,엽폭, 엽면적, 엽중, 지상부 생체중, 근장, 근중을 조사하였다. 25℃처리구에서는 초장, 엽면적, 엽중, 근중 모두 Pseudomonas sp. B와 glucosamine oligosaccharide를 혼합한 처리구가 가장 높았고, 30℃의 경우 초장과 엽중은 glusosamine oligosaccharide처리에서, 엽면적과 근중은 Pseudomonas sp. D2와 algin-oligosaccharide를 처리구에서 가장 좋은 생장 효과를 나타내었다. 35℃의 경우는 초장, 엽면적, 엽중, 근중 모두 Pseudomonas sp. B와 glucosamine oligosaccharide를 혼합한 처리구에서 효과가 컸다. 이상의 결과로 보아 고온기 칼랑코에의 분화 재배시 문제가 되는 생장억제현상은 천연제재와 미생물 제재를 혼합처리 함으로써 크게 개선시킬 수 있었다.

The biodegradation of high concentration of benzoate by enrichment culture with Pseudomonas sp. was investigated. During 50 days continuous culture, average of removal rate of benzoate and COD were 90% and 83%, respectively. And the enzymatic activity of catechal 2,3-dioxygenase was determined in the continuous culture but not Catechol 1,2-dioxygenase. On the other hand, Pseudomonas sp in the culture was investigated with SEM and the result was revealed that the cell shape was more demage according the higher concentration of benzoate.

토양으로부터 글주탐산 생산력이 우수한 세균을 분리 하여 Pseudomonas sp. L-10 으로 동정하였다. Pseudomonas sp. L-10에 의한 글루탐산 생산은 시험균주를 5% glucose, 0.5% urea와 yeast extract, 0.1% K_2HPO_4, 0.02% MgSO_4·7H_2O, 0.3% (NH_4)_2HPO_4의 조성을 가진 배지에 0.5㎍/ℓ의 비오틴을 첨가하여 pH 7.0으로 조정 한 후 30℃에서 30 시간 진탕배양하였을 때 가장 좋았으며 이 때 배양액 ㎖당 약 1.2㎎의 글루탐산이 생산되었다.

From 120 soil and activated sludge, the strains able to grow on Benzoate and m-Toluate have been isolated after selective enrichment which were later identified as Psudomonas sp. according to its morphological and biochemical characteristics. Ben-2 strain contained two plasmid DNA having about 120 Kb and below 2.0 Kb by agarose gel electrophoresis. Form the comparative investigation of catechol 1,2-oxygenase and catechol 2,3-oxygenase activities in Ben-2 strain and its cured strain, Ben-2 strain has both of these two enzymes while cured strain has catechol 1,2-oxygenase only.

A microorganism, isolated from soil and designated Pseudomonas sp13, produced two kinds of rhamnolipid in the medium containing glucose as carbon source. There were both rhamnolipid contain L-rhamnose and β-hydroxydecanoic acid. Coumpound A and B elucted chloroform-methanol mixed solution of silicic acid column chromatography and recrystallized from a mixture of ether and n-hexane. Studies on the structure of these products reveled that compound A is L-rhamnopyranosyl-β-hydroxydecanoyl-β-hydroxydecanoic acid and compound B is L-rhamnopyranosyl-L-rhamnopyranosyl-β-hydroxydecanoyl-β-hydroxydecanoic acid.

오이덩굴쪼김병균 Fusarium oxysporum f. sp. cucumerinum의 소형분생포자는 물한천배지상에서 Fe-EDDHA를 처리하였을 때 시간이 경과됨에 따라 발아율이 증가되어 무처리와 유의차를 보이지 않았으나 발아관의 길이는 현저하게 짧았다. Pseudomonas putid의 Siderophore를 처리하였을 때는 포자의 발아율과군사신장이 모두 현저하게 억제되었다. 토양중에 형성된 후막포자가 발아하는데 필요한 영양물질로 Glucose, Peptone을 각각 씩 첨가하였을 때 에 달하는 높은 발아율을 나타냈고, Glucose 와 Asparagine 를 첨가한 처리도 의 발아율을 보였다. 오이의 근권토양에서 후막포자는 발아후 10일된 유묘에서 의 발아율을 보인 반면 2일된 유묘에서는 정도 밖에 안되었으며, 10일 이상 경과된 묘에서도 발아율이 증가되지 않았다. 근권토양에 Fe-EDDHA를 첨가한 처리와 P. putida를 접종한 처리는 후막포자의 발아를 현저히 억제하였으며, 근권부위에 영양물질을 첨가한 처리에서도 같은 경향이었다. 그러나 비근권토양에 영양물질을 첨가하여 후막포자를 발아시켰을 경우 Fe-EDDHA나 P. putida의 발아 억제 효과가 뚜렷하게 인정되지 않았다. 근권토양에서 후막포자 발아 억제효과는 Fe-EDDHA보다 P. putida를 접증한 처리가 더 큰것으로 나타났다.

Three biphenyl-degrading microorganisms were isolated from polluted soil samples in Sasang-gu, Busan. Among them, isolate DS-94 showing the strong degrading activity was selected. The morphological, physiological, and biochemical characteristics of DS-94 were investigated by API 20NE and other tests. This bacterium was identified as the genus Pseudomonas by 16S rDNA sequencing and designated as Pseudomonas sp. DS-94. The optimum temperature and pH for the growth of Pseudomonas sp. DS-94 were 25℃ and pH 7.0, respectively. This isolate could utilize biphenyl as sole source of carbon and energy. Biphenyl-degrading efficiency of this isolate was measured by HPLC analysis. As a result of biological biphenyl-degradation at high biphenyl concentration (500 mg/L), biphenyl-removal efficiency by this isolate was 73.5% for 7 days.

From sludge of S municipal wastewater treatment plant in Busan, Korea, we isolated the denitrifier DN-9 which showed the ability of denitrification under aerobic condition by the color change and gas formation in liquid culture with Giltay medium. The isolated strain was identified as Pseudomonas sp. DN-9 on the basis of the morphological, physiological, biochemical and nucleotide sequence analysis of 16S rRNA. The isolated strain, Pseudomonas sp. DN-9, has cytochrome cd1 nirS of nitrite reductase. By the co-existance of additional ammonium and nitrate ion, the strain was not affected largely on growth in SL series broth. It seemed the result of denitrification. Although Pseudomonas sp. DN-9 has a good nitrate reduction activity under aerobic condition, the activity is less than Pseudomonas stutzeri in same cultivation condition. However, Escherichia coli had little the activity of aerobic denitrification and Pseudomonas putida showed lower activity of aerobic denitrification than Pseudomonas sp. DN-9 and Pseudomonas stutzeri in this study.

A biosurfactant-producing microorganism was isolated from activated sludge by enrichment culture when grown on a minimal salt medium containing n-hexadecane as a sole carbon source. This microorganism was identified as Pseudomonas sp. and it was named Pseudomonas sp. EL-G527. It's optimal culture condition is 2% n-hexadecane, 0.2% NH4NO3, 0.3% KH2PO4, 0.3% K2HPO4, 0.02% MgSO4ㆍ7H2O, 0.0025% CaCl2ㆍ6H2O, 0.0015% FeSO4ㆍ7H2O in 1ℓ distilled water and initial pH 7.0. Cultivation was initiated with a 2% inoculum obtained from starter cultures grown in 30 ㎖ of the same medium in 250 ㎖ flask. They were cultivated at 30 ℃ in reciprocal shaking incubator and the highest biosurfactant production was observed after 4 days.

Pseudomonas sp. EL-04J was previously isolated from phenol-acclimated activated sludge. This bacterium was capable of degrading phenol and cometabolizing trichloroethylene (TCE). After precultivation in the mineral salts medium containing phenol as a sole carbon source, Pseudomonas EL-04J degraded 90% of TCE 25μM within 20 hours. Thus, phenol-induced Pseudomonas sp. EL-04J cells can degrade TCE. Following a transient lag period, Pseudomonas sp. EL-04J cells degraded TCE at concentrations of at least 250μM with no apparent retardation in rate, but the transformation capacity of such cells was limited and depended on the cell concentration. The degradation rate of TCE followed the Michaelis-Menten kinetic model. The maximum degradation rate (Vmax) and saturation constant (Km) were 7nmo ℓ/min·㎎ cell protein and 11μM, respectively. Cometabolism of TCE by phenol fed experiment was evaluated in 50·mℓ serum, vial that contained 10 ㎖ of meneral sals medium supplemented with 10μM TCE. TCE degradation was inhibited in the initial period of 1 mM phenol addition, but after that time Pseudomonas sp. EL-04J cells degraded TCE and showed cell growth.

The effects of nutritional sources on growth of Pseudomonas sp. P2 were investigated in medium containing biphenyl as a carbon source. To determine characterization of Pseudomonas sp. P2, the incubation time was determined to 100 h of the log phase in the growth curve. The optimal compositions for the growth of Pseudomonas sp. P2 degrading polychlorinated biphenyls (PCBs) were 1000 ㎎/L NH4NO3, 1000 ㎎/L KH2PO4, 100 ㎎/L MgSO4·7H2O, 30 ㎎/L CaCl2·2H2O, 200 ㎎/L NaCl, and 10 ㎎/L FeSO4·7H2O. Pseudomonas sp. P2 showed the degradability of 59.3 %, 57.6%, 51.4%, and 48.7% at 500 ㎎/L, 1000 ㎎/L, 1500 ㎎/L, and 2000 ㎎/L of the PCBs within insulating oil after 100 h incubation under the optimum conditions, respectively.

Optimal biodegradation kinetics models to the initial nonylphenol ethoxylates-30 concentration were investigated and had been fitted by the linear regression. Microorganisms capable of degrading nonylphenol ethoxylates-30 were isolated from sewage near Ulsan plant area by enrichment culture technique. Among them, the strain designated as EL-10K had the highest biodegradability and was identified as Pseudomonas from results of taxonomical studies. The optimal conditions for the biodegradation were 1.0 g/l of nonylphenol ethoxylates-30 and 0.02 g/l of ammonium nitrate at pH 7.0 and 30℃. The highest degradation rate of nonylphenol ethoxylates-30 was about 89% for 30 hours incubation on the optimal condition. Biodegradation date were fit by linear regression to equations for 3 kinetic models. The kinetics of biodegradation of nonylphenol ethoxylates was best described by first order model for 0.1 ㎍/l nonylphenol ethoxylates-30 ; by Monod no growth model and Monod with growth model for 0.5 ㎍/ml and 1.0, 5.0 ㎍/ml, respectively.