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1.
Two strains of Pseudomonas corrugata, (1 and 7), isolated from subtropical and temperate soils in Sikkim Himalaya, respectively, were subjected to Petri-dish as well as plant-based bioassay to examine their potential for disease suppression against three major pathogens of maize. A mixture of Pythium ultimum, P. arrhenomanes and Fusarium graminearum was introduced in the soil; maize seed inoculated with one of the two strains of Pseudomonas corrugata (1 or 7) were sown in pots containing such soil. The bacterial inoculation resulted in significant disease suppression as well as growth promotion of seedlings. The bacterial strains were also evaluated for their intrinsic antibiotic resistance against a range of concentrations of ten antibiotics. While the bacteria were found to be sensitive to gentamycin and rifampicin, they exhibited resistance against ampicillin, carbenicillin and penicillin, even at high concentrations. 相似文献
2.
Nataliya E. Suzina Vitaly I. Duda Ljudmila A. Anisimova Vladimir V. Dmitriev Alexander M. Boronin 《Archives of microbiology》1995,163(4):282-285
The ultrastructure of strains Pseudomonas putida BS228 and Pseudomonas aeruginosa ML4262 harboring plasmids pBS10, pBS31, and pBS221, which determine resistance to potassium tellurite, was studied. Bacteria were grown in media containing increasing concentrations of potassium tellurite. Crystalline structures containing tellurium appeared in their periplasmic space. The dynamics of crystal growth was studied. Crystals were released into the medium by pinching off of the outer membrane vesicles containing growing crystals. A possible mechanism of this process was described; cytobiochemical peculiarities were discussed. 相似文献
3.
E. Silveira P.P. Marques S.S. Silva J.L. Lima-Filho A.L.F. Porto E.B. Tambourgi 《International biodeterioration & biodegradation》2009,63(2):230-235
Pigment is the first contaminant to be recognised in bodies of water and wastewater. Besides the aesthetic problem, dyes obstruct light and reduce oxygen mass transfer. This paper describes the selection of Pseudomonas strains with the ability to remove colour from textile industrial dyes. Four Pseudomonas species were tested against 14 commercial industrial dyes. Pseudomonas cepacia exhibited no growth at all on plates containing dyes (1 g l?1), whereas Pseudomonas aeruginosa, Pseudomonas oleovorans and Pseudomonas putida exhibited considerable growth. Decolourization in a liquid culture revealed that P. oleovorans is more viable for decolourizing textile dyes, as it achieved over 80% colour removal for two of the 14 dyes studied; it also proved to be more tolerant to high dye concentrations. 相似文献
4.
The effect of the addition of a recombinant plasmid containing the pglA gene encoding an alpha-1,4-endopolygalacturonase from Pseudomonas solanacearum on the growth of Pseudomonas aeruginosa and Pseudomonas putida in soil and rhizosphere was determined. Despite a high level of polygalacturonase production by genetically engineered P. putida and P. aeruginosa, the results suggest that polygalacturonase production had little effect on the growth of these strains in soil or rhizosphere. 相似文献
5.
The production of cytokinins by plant-associated bacteria was examined by radioimmunoassay. Strains producing trans-zeatin were identified in the genera Agrobacterium and Pseudomonas. Agrobacterium tumefaciens strains containing nopaline tumor-inducing plasmids, A. tumefaciens Lippia isolates, and Agrobacterium rhizogenes strains produced trans-zeatin in culture at 0.5 to 44 micrograms/liter. Pseudomonas solanacearum and Pseudomonas syringae pv. savastanoi produced trans-zeatin at levels of up to 1 mg/liter. In vitro cytokinin biosynthetic activity was measured for representative strains and was found to correlate with trans-zeatin production. The genetic locus for trans-zeatin secretion (tzs) was cloned from four strains: A. tumefaciens T37, A. rhizogenes A4, P. solanacearum K60, and P. syringae pv. savastanoi 1006. Southern blot analysis showed substantial homology of the Agrobacterium tzs genes to each other but not to the two Pseudomonas genes. 相似文献
6.
Growth of genetically engineered Pseudomonas aeruginosa and Pseudomonas putida in soil and rhizosphere. 总被引:1,自引:1,他引:0
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The effect of the addition of a recombinant plasmid containing the pglA gene encoding an alpha-1,4-endopolygalacturonase from Pseudomonas solanacearum on the growth of Pseudomonas aeruginosa and Pseudomonas putida in soil and rhizosphere was determined. Despite a high level of polygalacturonase production by genetically engineered P. putida and P. aeruginosa, the results suggest that polygalacturonase production had little effect on the growth of these strains in soil or rhizosphere. 相似文献
7.
Several mutants of Pseudomonas syringae subsp. savastanoi were tested for their ability to sense and respond to a chemotactic gradient in low concentrations of yeast extract. The mutants were deficient in one or both of the genes coding for the synthesis of the plant hormones indole-3-acetic acid (IAA) and isopentenyl adenosine. Mutations which resulted in the loss of IAA production were due to the loss of the entire plasmid containing the iaa operon or to an 18-kb deletion of the iaa region. Additional mutants tested were deficient in their ability to produce isopentenyl adenosine as a result of the loss of the ptz-bearing plasmid. In all cases, strains which had lost the ability to produce IAA exhibited enhanced motility of up to 2.5 times that of the wild type (IAA+) in medium containing 0.01% yeast extract. No differences in motility were observed on medium containing lower concentrations of yeast extract. The presence or absence of the cytokinin plasmid and the presence or absence of inorganic nitrogen in the medium had no effect on the relative mobility of the strains. 相似文献
8.
Intrinsic and acquired resistance to quaternary ammonium compounds in food-related Pseudomonas spp 总被引:1,自引:0,他引:1
AIMS: To determine the sensitivity of a strain used for disinfectants testing (Pseudomonas aeruginosa ATCC 15442) and food-associated isolates to benzalkonium chloride and didecyl dimethylammonium chloride (DDAC). To determine whether the increase in bacterial resistance after adaptation to DDAC can be associated with phenotypic changes. To test the activity of alternative disinfectants to eliminate resistant Pseudomonas spp. METHODS AND RESULTS: Pseudomonas aeruginosa ATCC 15442 was among the most resistant strains tested using a bactericidal suspension test. Growth of a sensitive Ps. fluorescens in gradually higher concentrations of DDAC resulted in stable higher resistance and to some cross-resistance to several antibacterial agents, with the exception of disinfectants containing chloramine T, glutaraldehyde or peracetic acid. It was shown by microscopy that adaptation was followed by loss of flagella, and slime formation. Removal of the slime by sodium dodecyl sulphate resulted in partial loss of the acquired resistance. CONCLUSIONS: Pseudomonas spp. may adapt to survive against higher concentrations of quaternary ammonium compounds (QACs), but resistant strains can be eliminated with chemically unrelated disinfectants. SIGNIFICANCE AND IMPACT OF THE STUDY: The work supports the rotation of disinfectants in food processing environments for avoiding the development of bacterial resistance to QACs. The alternating disinfectants should be chosen carefully, because of possible cross-resistance. 相似文献
9.
Heme oxygenases (HO) degrade heme yielding iron, carbon monoxide and one of four possible biliverdin (BV) isomers. Pseudomonas aeruginosa PAO1 is thus far the only organism to contain two HOs with different regiospecificities: BphO and PigA. While BphO cleaves heme to exclusively yield BV IXα, PigA produces the BV isomers IXβ and IXδ. We bioinformatically identified putative HOs in diverse Pseudomonas strains, tested their enzymatic functionality and determined their regiospecificity. Surprisingly, even high amino acid sequence identities to the P. aeruginosa HOs were not sufficient to correctly predict the HO regiospecificity in all cases. Based on our results, Pseudomonas strains differ in their HO composition containing either BphO or PigA or both HO types. Concomitantly with the existence of bphO is the occurrence of at least one gene encoding a bacterial phytochrome implying that only BV IXα is the sufficient phytochrome chromophore. In contrast, pigA genes are organized in gene clusters associated with iron utilization implying a role of PigA in iron acquisition. However, at least in strains containing no PigA this function maybe fulfilled by BphO. Only a combination of homology searches and analyses of genetic environments is appropriate for a reliable prediction of the regiospecificity of Pseudomonas HOs. 相似文献
10.
O Lochmann F Vymola V Chaloupecky 《Journal of hygiene, epidemiology, microbiology, and immunology》1975,19(1):61-71
Haemolysins of 4 strains of Pseudomonas aeruginosa producing different fractions [II, 2 + II, I + II + III] were studied. The production of specific antibodies was demonstrated making possible the immunoelectrophoretic record of the whole lysin and of the individual fractions. Tests on laboratory animals [mice, rabbits] showed a high degree lethal and dermonecrotic property of the lysin containing the fractions II + III and I + II + III. 相似文献
11.
A strain of food-poisoning bacterium has been isolated by Jin Jiexiang (1963) in China from the fermented cornflour that has gone bad. These pathogenic microorganism has been identified and named Pseudomonas by Zhao Naixin in 1988, which is the same species as P. cocovenenans. The characteristics of them were conformed to these of the species P. cepacia of section 2 of the genus Pseudomonas. In view of the fact that the fine structures of the above mentioned three strains of Pseudomonas have not been described yet, we decided to observe them with electron microscope. Results indicate there are many things in common among the three strains, such as: appearing short rods, 0.6-0.8 microns in diameter by 1.5-2.0 microns in length, one polar multiflagella; non-pili, non-capsules, non-endospores; containing intranuclear inclusions (electron-dense bodies or concentric laminae bodies), accumulating intracytoplasmic PHB granules; forming filaments, minicells and bizarrecells; producing extracellular cellulose-like materials by the three strains have not been reported previously. 相似文献
12.
Out of 20 Pseudomonas phages, 17 were most suitable for typing of Pseudomonas aeruginosa strains isolated from different sources of human infections. These phages have been classified into three taxons based on coefficient of correlation of their lytic activity. Out of these strains only one appeared nontypeable. 240 distinquished phagotypes were classified into three groups and seven subgroups. This schema of classification was used in the epidemiological investigations of the Pseudomonas strains in relation to the category of infection and the place of isolation. Some statisticaly significant differences were detected. Various possibilities of applications of typing set of Pseudomonas phages are discussed. 相似文献
13.
目的:观察亚胺培南对铜绿假单胞菌标准菌株和耐药菌株体外培养释放DNA的影响。方法:选择铜绿假单胞菌的标准菌株和临床分离耐药菌株作为实验菌株,检测其亚胺培南的最低抑菌浓度(MIC),琼脂糖凝胶电泳法观察不同浓度亚胺培南作用下铜绿假单胞菌的DNA释放情况,并用Quantity One软件分析所释放DNA片段的分子量和含量。结果:亚胺培南作用下铜绿假单胞菌从1/2MIC开始释放小片段DNA,大于1/2MIC仅释放l条大片段DNA,且含量少,等于1/2MIC可释放3条DNA,但无小片段DNA,小于1/2MIC可释放4.5条DNA,且含量多。1/16MIC时,标准菌株释放的第1、5条DNA片段含量偏少,3、4条DNA片段含量偏多,而耐药菌株相反。耐药菌株与标准菌株相比释放的DNA片段有所不同,耐药菌株比标准菌株多释放一条DNA片段(第2条),分子量为2784bp,耐药菌株的第1、3、4、5条DNA片段分子量均比标准菌株小。耐药菌株释放的第3、4、5条DNA含量明显高于标准菌株,P〈0.01,其统计有显著学意义。结论:不同亚胺培南浓度作用下,铜绿假单胞菌会释放不同片段大小和含量的DNA分子,耐药菌株与标准菌株释放的DNA片段数量和含量有明显差异,其与耐药机制的关系值得进一步研究。 相似文献
14.
Ellaiah P Prabhakar T Sreekanth M Taleb AT Raju PB Saisha V 《Indian journal of experimental biology》2002,40(9):1083-1086
Microorganisms, that degrade hydrocarbon were isolated and screened for their biosurfactant activity. A total of 68 strains were isolated and tested for their glycolipid activity of which 4 isolates showed good glycolipid activity. Isolate K10 gave the maximum biosurfactant production in medium A (containing kerosene as a sole carbon source) as compared to medium B (containing glucose as a sole carbon source). Characterization of isolate K10 showed that it belongs to Pseudomonas species. 相似文献
15.
Phytopathogenic strains of Pseudomonas syringae are exposed to plant-produced, detrimental levels of hydrogen peroxide during invasion and colonization of host plant tissue. When P. syringae strains were investigated for their capacity to resist H2O2, they were found to contain 10- to 100-fold-higher levels of total catalase activity than selected strains belonging to nonpathogenic related taxa (Pseudomonas fluorescens and Pseudomonas putida) or Escherichia coli. Multiple catalase activities were identified in both periplasmic and cytoplasmic fluids of exponential- and stationary-phase P. syringae cells. Two of these activities were unique to the periplasm of P. syringae pv. glycinea. During the stationary growth phase, the specific activity of cytoplasmic catalases increased four- to eightfold. The specific activities of catalases in both fluids from exponential-phase cells increased in response to treatment with 0.25 to 10 mM H2O2 but decreased when higher H2O2 concentrations were used. In stationary-growth phase cultures, the specific activities of cytoplasmic catalases increased remarkably after treatment with 0.25 to 50 mM H2O2. The growth of P. syringae into stationary phase and H2O2 treatment did not induce synthesis of additional catalase isozymes. Only the stationary-phase cultures of all of the P. syringae strains which we tested were capable of surviving high H2O2 stress at concentrations up to 50 mM. Our results are consistent with the involvement of multiple catalase isozymes in the reduction of oxidative stress during plant pathogenesis by these bacteria. 相似文献
16.
Multiple periplasmic catalases in phytopathogenic strains of Pseudomonas syringae. 总被引:6,自引:0,他引:6
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Phytopathogenic strains of Pseudomonas syringae are exposed to plant-produced, detrimental levels of hydrogen peroxide during invasion and colonization of host plant tissue. When P. syringae strains were investigated for their capacity to resist H2O2, they were found to contain 10- to 100-fold-higher levels of total catalase activity than selected strains belonging to nonpathogenic related taxa (Pseudomonas fluorescens and Pseudomonas putida) or Escherichia coli. Multiple catalase activities were identified in both periplasmic and cytoplasmic fluids of exponential- and stationary-phase P. syringae cells. Two of these activities were unique to the periplasm of P. syringae pv. glycinea. During the stationary growth phase, the specific activity of cytoplasmic catalases increased four- to eightfold. The specific activities of catalases in both fluids from exponential-phase cells increased in response to treatment with 0.25 to 10 mM H2O2 but decreased when higher H2O2 concentrations were used. In stationary-growth phase cultures, the specific activities of cytoplasmic catalases increased remarkably after treatment with 0.25 to 50 mM H2O2. The growth of P. syringae into stationary phase and H2O2 treatment did not induce synthesis of additional catalase isozymes. Only the stationary-phase cultures of all of the P. syringae strains which we tested were capable of surviving high H2O2 stress at concentrations up to 50 mM. Our results are consistent with the involvement of multiple catalase isozymes in the reduction of oxidative stress during plant pathogenesis by these bacteria. 相似文献
17.
Expression of the argF gene of Pseudomonas aeruginosa in Pseudomonas aeruginosa, Pseudomonas putida, and Escherichia coli 总被引:3,自引:3,他引:0
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R' plasmids carrying argF genes from Pseudomonas aeruginosa strains PAO and PAC were transferred to Pseudomonas putida argF and Escherichia coli argF strains. Expression in P. putida was similar to that in P. aeruginosa and was repressed by exogenous arginine. Expression in E. coli was 2 to 4% of that in P. aeruginosa. Exogenous arginine had no effect, and there were no significant differences between argR' and argR strains of E. coli in this respect. 相似文献
18.
Abstract Cured derivatives of Pseudomonas strains carrying TOL or NAH plasmids were obtained by selection on plates containing benzoic acid at almost the inhibitory concentration. Bacteria containing TOL and NAH plasmids produced deep blue colonies on m -toluate/indole or naphthalene/indole plates and weaker reactions on benzoate/indole plates. The indigo reaction of the TOL strains was ascribed to the plasmid-coded benzoate/toluate oxidase. Strains that had been cured of their plasmids did not produce indigo. 相似文献
19.
Factors contributing to the survival of poultry associated Pseudomonas spp. exposed to a quaternary ammonium compound 总被引:4,自引:4,他引:0
Resistance to benzalkonium chloride (BC) among Pseudomonas spp. isolated from poultry carcasses was determined and strategies for elimination of resistant strains evaluated. This investigation showed that resistance was quite common, about 30% of the isolates being able to grow in 200 μg ml−1 BC. Pseudomonas fluorescens strains were generally less susceptible than strains of Ps. lundensis and Ps. fragi. An overnight incubation in medium containing 200 μg ml−1 BC was sufficient to reduce the susceptibility of two Pseudomonas strains to the lethal effect of BC significantly. Adding EDTA enhanced the lethal effect of BC, but the effect was reduced after growing cells in medium containing BC and EDTA. Growth in medium with a quaternary ammonium compound (QAC) rendered the cells more susceptible to chlorine, phenolics and alkylaminoacetate. These results indicate that alternating use of QACs with these compounds can be used to avoid build-up of resistant strains. In addition, increased temperatures improved the lethal effect of BC and should be considered when planning disinfection routines. 相似文献
20.
Variable Ammonia Production Among Smooth and Rough Strains of Pseudomonas pseudomallei: Resemblance to Bacteriocin Production 总被引:4,自引:1,他引:3
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The colonial morphology of some strains of Pseudomonas pseudomallei was correlated with certain biochemical and physiological traits. After 3 days of growth on Wahba or heart infusion agars, smooth-colony strains generated toxic amounts of ammonia. Under the same conditions, the rough strains simultaneously produced oxalic acid which decreased the inhibitory concentration of ammonia. The ammonia-ammonium concentrations in smooth cultures exhibited certain bacteriocin-like characteristics. An unusually stable, smooth strain (strain 165) was chosen to compare and emphasize any differences with typical, rough strain 7815. Three-day-old smooth cultures grown on Wahba agar containing 3% (w/v) glycerol demonstrated ammonia toxicity. The substitution of glucose for glycerol completely obviated this toxicity. In highly aerated Wahba broth containing glucose, the amount of ammonia found in strain 165 smooth cultures and the amount of oxalic acid found in strain 7815 rough cultures were greatly reduced. In Difco nitrate broth smooth strain 165 did not form gas, and it reduced nitrate to nitrite only. Strain 7815 produced a gas and reduced both nitrate and nitrite. 相似文献