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1.
The P. aeruginosa-related plant growth beneficial strain 7NSK2 was able to increase the yield of barley, wheat, 4 varieties of maize, cucumber, spinach and corn salad from 10 to 24%. Siderophore deficient mutants of 7NSK2, obtained by Tn5-mutagenesis were never able to stimulate plant growth, although their root colonizing capacities were not impaired. The effect of 7NSK2 inoculation on cucumber dry weight was more pronounced in EDDHA-treated soil (+18%) than in the control soil (+10%). Soil inoculation with 7NSK2 in a FeEDDHA-treated soil had no effect on plant growth.The 7NSK2 strain and a sid- mutant MPFM1 could make use of a variety of Fe(III) siderophore complexes, while the pyoverdin produced by 7NSK2 was only used by a limited number of other fluorescent Pseudomonas strains. Many more root than soil bacteria were able to use Fe-desferal or Fe-pyoverdin to overcome iron-shortage. It is postulated that pyoverdin production plays an important role in plant growth stimulation, but is not the only factor involved. Pyoverdin production might be very strategic, especially in the rhizosphere, not only to supply the cell with iron, but also to keep other microorganisms, which might be harmful to 7NSK2 and to the plant, at bay. 相似文献
2.
The Pseudomonas aeruginosa siderophore pyochelin is obtained from the bacterial culture medium as a mixture of two epimers. Chromatically isolated pure stereoisomers equilibrate readily in most solvents. Experiments will be reported which allow to isolate one of the isomers in pure form and which shed some additional light on the epimerization reaction. 相似文献
3.
4.
Andrea Johnová Magda Dobiová Mohamed A. Abdallah Pavel Kyslík 《Biotechnology letters》2001,23(21):1759-1763
Fur mutants FPA12 and FF13 of strains Pseudomonas aeruginosa PAO1 and Fe10, respectively, were prepared and their production of pyoverdin evaluated. The strains were cultivated in stirred bioreactor in iron-deficient and iron-supplemented medium containing Casamino acids (CA) or succinate as a source of carbon and energy. When the pyoverdin production rate reached its maximum, the demand of iron-depleted cultures for O2 was decreased. Mutant FF13 overproduced pyoverdin in both iron-depleted (862 mg l–1) and iron-supplemented (428 mg l–1) CA medium and could also be used to produce pyoverdin when grown in a conventional stirred tank fermenter. 相似文献
5.
Corinne Vander Wauven Alfred Jann Dieter Haas Thomas Leisinger Victor Stalon 《Archives of microbiology》1988,150(4):400-404
Most Pseudomonas aeruginosa PAO mutants which were unable to utilize l-arginine as the sole carbon and nitrogen source (aru mutants) under aerobic conditions were also affected in l-ornithine utilization. These aru mutants were impaired in one or several enzymes involved in the conversion of N2-succinylornithine to glutamate and succinate, indicating that the latter steps of the arginine succinyltransferase pathway can be used for ornithine catabolism. Addition of aminooxyacetate, an inhibitor of the N2-succinylornithine 5-aminotransferase, to resting cells of P. aeruginosa in ornithine medium led to the accumulation of N2-succinylornithine. In crude extracts of P. aeruginosa an ornithine succinyltransferase (l-ornithine:succinyl-CoA N2-succinyltransferase) activity could be detected. An aru mutant having reduced arginine succinyltransferase activity also had correspondingly low levels of ornithine succinyltransferase. Thus, in P. aeruginosa, these two activities might be due to the same enzyme, which initiates aerobic arginine and ornithine catabolism.Abbreviations OAT
ornithine 5-aminotransferase
- SOAT
N2-succinylornithine 5-aminotransferase
- Oru
ornithine utilization
- Aru
arginine utilization 相似文献
6.
A. Premalatha G. Suseela Rajakumar 《World journal of microbiology & biotechnology》1994,10(3):334-337
Five Pseudomonas species were tested for ability to degrade pentachlorophenol (PCP). Pseudomonas aeruginosa completely degraded PCP up to 800 mg/l in 6 days with glucose as co-substrate. With 1000 mg PCP/l, 53% was degraded. NH4
+ salts were better at enhancing degradation than organic nitrogen sources and shake-cultures promoted PCP degradation compared with surface cultures. Degradation was maximal at pH 7.6 to 8.0 and at 30 to 37°C. Only PCP induced enzymes that degraded PCP and chloramphenicol inhibited this process. The PCP was degraded to CO2, with release of Cl-.The authors are with the Bacteriology Laboratory, Central Leather Research Institute, Madras-600 020, India. 相似文献
7.
Fur mutants (Mnr) of Pseudomonas aeruginosaFe10 (FF13 and FF28) and PAO1 (FPA12) were evaluated for the pattern of deregulation of pyoverdin synthesis in iron-replete medium with Casamino acids [CAM(Fe)] or succinate [SM(Fe)]. With respect to siderophore synthesis, we found in CAM(Fe) medium two Fur phenotypes: FurA (full deregulation, FF13) and FurB (partial deregulation, FF28 and FPA12). Fur mutants compared to parental strains grew with slower specific growth rates on SM(0) and CAM(0) media in a stirred bioreactor. Fur mutants grew in SM(0) with about half of that in CAM(0). 相似文献
8.
Interleukin-1-deficient mice exhibit high sensitivity to gut-derived sepsis caused by Pseudomonas aeruginosa 总被引:1,自引:0,他引:1
Horino T Matsumoto T Uramatsu M Tanabe M Tateda K Miyazaki S Nakane A Iwakura Y Yamaguchi K 《Cytokine》2005,30(6):339-346
BACKGROUND: The role of interleukin (IL)-1 in infectious diseases is controversial; some investigators indicated an enhancing effect of IL-1 on host resistance whereas others demonstrated the protective role of IL-1 receptor antagonist in infection. We evaluated the role of endogenous IL-1 in gut-derived sepsis caused by Pseudomonas aeruginosa, by comparing IL-1-deficient mice and wild-type (WT) mice. METHODS: Gut-derived sepsis was induced by intraperitoneal injection of cyclophosphamide after colonization of P. aeruginosa strain D4 in the intestine. RESULTS: The survival rate of IL-1-deficient mice was significantly lower than that of WT mice (P<0.01). Bacterial counts in the liver, mesenteric lymph node and blood were significantly higher in IL-1-deficient mice than in WT mice. Tumor necrosis factor alpha and IL-6 in the liver were significantly higher in IL-1-deficient mice than in WT mice. In vitro, phagocytosis and cytokine production by macrophages were impaired in IL-1-deficient mice compared with WT mice. CONCLUSION: Our results indicate a critical role for IL-1 during gut-derived P. aeruginosa sepsis. The results also suggest that both impairment of cytokine production and phagocytosis by macrophages are caused by IL-1 deficiency and lead to impaired host response. 相似文献
9.
Indirect utilization of the phytosiderophore mugineic acid as an iron source to rhizosphere fluorescent Pseudomonas 总被引:1,自引:0,他引:1
The phytosiderophore mugineic acid (MA) was studied as a source of iron for rhizosphere fluorescent pseudomonads. 55Fe supplied as Fe-MA was taken up by Pseudomonas putida WCS358, B10 and St3 grown under iron deficient conditions. The uptake decreased when the bacteria were grown in the presence of iron. However, no differences in uptake were observed when a siderophore deficient mutant was tested. Since ligand exchange between pseudobactin and MA was shown to occur rapidly with a half-life of 2 h, MA mediated iron uptake probably proceeds through this indirect mechanism. The ecological implications of these findings are discussed. 相似文献
10.
Paulette W. Royt 《Biometals》1990,3(1):28-33
Summary Incubated in the presence of [55Fe]ferri[14C]pyoverdine, iron-poorPseudomonas aeruginosa accumulated more55Fe than14C over a 60-min period. Distribution studies showed (a) more14C than55Fe in the soluble fraction during the first 20 min, (b) approximately 60% of the55Fe associated with the membranes at 60 min, and (c) approximately 85% of the14C in the soluble fraction at 60 min. Cells osmotically shocked after incubating with [55Fe]ferri[14C]pyoverdine for 60 min released55Fe but not14C, suggesting separation of metal and ligand in the periplasmic space. Whereas the mechanism of dissociation of iron and ligand is not known, the decrease in transport observed in the presence of dipyridyl suggests involvement of reduction in this process. Transport of iron was energized by the proton motive force instead of by intracellular levels of ATP. The hydrogen ion gradient was the major driving force of transport. Cyanide-poisoned cells accumulated more14C than55Fe over 60 min. Here, iron accumulated in the soluble fraction instead of on the membranes. 相似文献
11.
Triki-Ellouz Yosra Ghorbel Basma Souissi Nabil Kammoun Sadok Nasri Moncef 《World journal of microbiology & biotechnology》2003,19(1):41-45
Fish powders and fish protein hydrolysates (FPH) from sardinella (Sardinella aurita) were prepared and tested as growth media for alkaline protease production by Pseudomonas aeruginosa MN7. Cultivated in fish substrate as carbon source, the strain exhibited a slightly greater protease production (about 7800 U ml–1) than that obtained with commercial peptones (about 7222 U ml–1). Furthermore, P. aeruginosa MN7 produced the same amount of protease when cultivated in medium containing only fish substrate or that containing all ingredients, indicating that the strain can obtain its carbon and nitrogen requirements directly from whole fish proteins. Moreover, it was found that extensive hydrolysis of fish proteins did not increase protease formation. Protease production in media containing only FPH prepared by Alcalase was about 70% of those obtained with MN7 protease digest of fish protein or with meat-fish powder. These results indicate that sardinella substrates are an excellent carbon and nitrogen source for the growth of P. aeruginosa MN7 and the production of protease. 相似文献
12.
Thomas Jahns 《Antonie van Leeuwenhoek》1992,62(3):173-179
The energy-dependent urea permease was studied in two strains ofPseudomonas aeruginosa, measuring the uptake (transport and metabolism) of14C-urea. In both strains urea uptakein vivo and urease activityin vitro differed significantly with respect to kinetic parameters, temperature and pH dependence and response to metabolic inhibitors. Ammonium strongly interfered both with the expression of the urea uptake system and its activity. The inhibition of the uptake activity by ammonium was partially relieved by hydraziniumsulfate, which prevented the translocation of ammonium into the cell, and in a methylammonium/ammonium transport-defective mutant of strain DSM 50071. Furthermore, methionine-sulfoximine, which prevented the intracellular glutamine formation from ammoniumvia inhibition of glutamine synthetase, relieved the inhibition of urea uptake by ammonium. These findings suggested that urea uptake activity inP. aeruginosa is regulated by intracellular glutamine.Abbreviations CCCP
carbonylcyanide-m-chlorphenylhydrazone
- DCCD
dicyclohexylcarbodiimide
- GS
glutamine synthetase
- MSX
methionine-sulfoximine 相似文献
13.
Cadmium and zinc appear in the combined forms and they are co-pollutants. Cd is the most hazardous metal ion for human beings
and causes renal dysfunction, liver and lungs damage, bone degeneration and blood damage. Though Zn is an essential nutrient,
excess of Zn is toxic. Biological process was more important because conventional methods fail to remediate these pollutants
due to high costs and less affordability. The screening and understanding of the functioning of microorganism plays an important
role in removal and recovery of metals from heavy-metal-polluted water and soil. In our study, the strain Pseudomonas aeruginosa BC15 was isolated from oil-mill-treated waste water and it showed to be highly resistant to 6 mM Cd and 20 mM Zn in the solid
and liquid media. The growth studies of BC15 strain in the medium without induction exhibited high tolerable capacity when
compared to other microbes. Pretreatment of P. aeruginosa BC15 with sub-lethal concentrations of Cd induced adaptive resistance to lethal doses of Cd. Cadmium-induced cells also showed
cross resistance to lethal concentration of zinc. The organism had high resistance against Cd and Zn. This has been clearly
proven through biosorption studies: Cd was absorbed up to 62% and Zn about 60% in single solution, whereas in binary solution
Cd was biosorbed up to 82% and Zn 85%. In conclusion, this study reveals the significance of using the strain P. aeruginosa BC15 in the bioremediation of Cd and Zn from industrial waste water and contaminated soil. 相似文献
14.
Isolation and characterization of mutant Pseudomonas aeruginosa strains unable to assimilate nitrate 总被引:2,自引:0,他引:2
Single-site mutants of Pseudomonas aeruginosa that lack the ability aerobically to assimilate nitrate and nitrite as sole sources of nitrogen have been isolated. Twentyone of these have been subdivided into four groups by transductional analysis. Mutants in only one group, designated nis, lost assimilatory nitrite reductase activity. Mutants in the other three transductional groups, designated ntmA, ntmB, ntmC, display a pleiotropic phenotype: utilization of a number of nitrogen-containing compounds including nitrite as sole nitrogen sources is impaired. Assimilatory nitrite reductase was shown to be the major route by which hydroxylamine is reduced in aerobically-grown cells.In memoriam of Professor R. Y. Stanier 相似文献
15.
Alginate acetylation influences initial surface colonization by mucoid Pseudomonas aeruginosa 总被引:4,自引:0,他引:4
Tielen P Strathmann M Jaeger KE Flemming HC Wingender J 《Microbiological research》2005,160(2):165-176
Mucoid strains of Pseudomonas aeruginosa overproduce the exopolysaccharide alginate, which is substituted with O-acetyl groups. Under non-growing conditions in phosphate buffer, a mucoid clinical strain formed microcolonies on steel surfaces, while an acetylation-defective mutant was unable to form cell clusters. Enzymatic degradation of alginate by alginate lyase prevented microcolony formation of the mucoid parent strain. In a continuous-culture flow-cell system, using gluconate minimal medium, the mucoid strain with acetylated alginate formed microcolonies and grew into heterogenous biofilms, whereas the acetylation-defective mutant produced a thinner and more homogeneous biofilm. A lowered viscosity of extracellular material from the acetylation-defective mutant indicated a weakening of exopolymer interactions by loss of acetyl groups. These results suggest that acetyl substituents are necessary for the function of high-molecular-mass alginate to mediate cell aggregation into microcolonies in the early stages of biofilm development by mucoid P. aeruginosa, thereby determining the architecture of the mature biofilm. 相似文献
16.
Janssen Dick B. op den Camp Huub J. M. Leenen Pieter J. M. van der Drift Chris 《Archives of microbiology》1980,124(2-3):197-203
Glutamine synthetase from Pseudomonas aeruginosa is regulated by repression/derepression of enzyme synthesis and by adenylylation/deadenylylation control. High levels of deadenylylated biosynthetically active glutamine synthetase were observed in cultures growing with limiting amounts of nitrogen while synthesis of the enzyme was repressed and that present was adenylylated in cultures with excess nitrogen.NADP-and NAD-dependent glutamate dehydrogenase could be separated by column chromatography and showed molecular weights of 110,000 and 220,000, respectively. Synthesis of the NADP-dependent glutamate dehydrogenase is repressed under nitrogen limitation and by growth on glutamate. In contrast, NAD-dependent glutamate dehydrogenase is derepressed by glutamate. Glutamate synthase is repressed by glutamate but not by excess nitrogen. 相似文献
17.
G. Soberón-Chávez J. Campos A. Haïdour J. L. Ramos J. Ortigoza 《World journal of microbiology & biotechnology》1996,12(4):367-372
A bacterium able to grow at the expense of some isomers in a commercial surfactant preparation consisting of branched-chain dodecylbenzenesulphonate was isolated (W51), and it was identified as a Pseudomonas aeruginosa strain. A faster growing derivative was selected (W51D) after enrichment in batch culture under microaerobic conditions, using the surfactant as the sole source of carbon and energy. Strain W51D is the first microorganism reported to degrade at least 70% of a branched-chain alkylbenzenesulphonate mixture and to be resistant to high concentrations of this surfactant. The ability to degrade the surfactant was shown to be transferred by conjugation to other P. aeruginosa strains and to an Escherichia coli strain.G. Soberón-Chávez and J. Campos are with the Instituto de Biotecnologia, Universidad Nacional Autónoma de México, Apdo Postal 510-3, Cuernavaca, Mor. 62250, México.A. Hädour and L. Ramos are with Estación Experimental del Zaidín, Consejo Superior de Investigaciones Cientificas, Protesor Albareda 1, Granada 18008, España. J. Ortigoza is with Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Apdo. Postal 42-186. México D.F. 11340. México. 相似文献
18.
Valli Nachiyar C Suseela Rajakumar G 《Journal of industrial microbiology & biotechnology》2006,33(10):845-849
Pseudomonas aeruginosa, isolated from soil near tannery effluent was able to degrade 8-anilino-1-naphthalenesulfonic acid (ANSA), a sulfonated aromatic amine. The organism degraded this amine up to a concentration of 1,200 mg l−1 using glucose and ammonium nitrate as carbon and nitrogen sources respectively. The degradation started when the organism reached its late exponential growth phase. Salicylic acid and β-ketoadipic acid were identified as intermediate compounds using HPLC and GC–MS and provide evidence for ortho pathway reactions. Further proof for the pathway is obtained from the dioxygenase activity of the strain growing exponentially in medium with ANSA and glucose. 相似文献
19.
Ana Carnicero Teresa B. Mansito José M. Roldán Miguel A. Falcón 《Archives of microbiology》1990,154(1):37-41
Staphylolytic enzyme, a specific peptidase produced by Pseudomonas aeruginosa, has been characterized by using immunochemical procedures. Lytic activity was detected in the extracellular medium of Pseudomonas cultures at the beginning of the stationary growth phase. No activity was detected in bacterial cells. However, lytic protein antigen was present in periplasmic and cytoplasmic fractions, suggesting that staphylolytic enzyme is synthesized as an inactive precursor which becomes active during translocation to the extracellular broth. Results obtained in immunolocalization experiments indicate the presence of the precursor in the outer part of cells. The export pathway of staphylolytic enzyme through the periplasmic space is proposed.Abbreviations DCE
dialyzed crude extract
- CFU
colonies forming units
- LU
lytic unit 相似文献
20.
Pseudomonas aeruginosa was transformed with pUC8:16, a pUC-based plasmid bearing the gene (vgb) encoding Vitreoscilla (bacterial) hemoglobin (VHb). Transformation was initially indicated by an increase in ampicillin resistance from 1500 to 2500 mg l–1. Presence of the plasmid in P. aeruginosa was confirmed by amplification of a portion of vgb from and detection of VHb in the transformant but not the untransformed host. Southern blot analysis further indicated that pUC8:16 existed as an autonomous plasmid rather than integrated into the chromosome of the P. aeruginosa transformant. 相似文献