共查询到20条相似文献,搜索用时 0 毫秒
1.
M. Sondossi H. W. Rossmoore J. W. Wireman 《Journal of industrial microbiology & biotechnology》1986,1(2):97-103
Summary A formaldehyde resistant (R) phenotype ofPseudomonas aeruginosa was isolated from a formaldehydesensitive (S) parent by sequential treatment with 1,3,5-tris-(ethyl)hexahydro-s-triazine (ET). The resistance of the (R) strain to treatment with ET was approximately 3-fold higher than the parental (S) strain. Two modes of resistance to ET, and simultaneous resistance to formaldehyde, are demonstrated: (1) transient or induced resistance is expressed during shor-term exposure to ET, and this resistance is gradually lost during subsequent growth in the absence of ET, and (2) resistance that results from a stable phenotypic change in the (S) strain following sequential treatment with ET ((R) strain phenotype). The observed activities of three forms of the formaldehyde oxidizing enzyme, formaldehyde dehydrogenase, are strongly correlated with the relative response of the (S) and (R) strains to treatment with ET. The observed resistance of the (R) strain appears to be due to high levels of an NAD+-linked, glutathione-dependent form of formaldehyde dehydrogenase as well as a dye-linked formaldehyde dehydrogenase. The transient or induced response of the (R) strain involves an increase in activity of the dye-linked formaldehyde dehydrogenase. The induced response of the (S) strain and an ATCC strain ofP. aeruginosa, however, is correlated with the two forms of the NAD+-linked enzyme (glutathione-dependent (EC 1.2.1.1) and independent (EC 1.2.1.46)) with no contribution from the dye-linked enzyme. 相似文献
2.
M. J. Espuny C. Andres M. E. Mercade M. Robert M. A. Manresa J. Guinea 《Antonie van Leeuwenhoek》1991,60(2):83-86
For the first time R-bodies are described in a new strain 44T1 ofPseudomonas aeruginosa. Its size was measured as being 0.22 to 0.37 m of width per 0.27 to 0.41 m of length and 5 to 9 spiral turns about 16 nm. These structures are similar to previously observed in bacteria and are related with physiological state of bacteria in minimal conditions of growth. 相似文献
3.
T. Herbert Manoharan 《Journal of biosciences》1980,2(2):107-120
The enzymes involved in the regulation of L-hydroxyproline degradation inPseudomonas aeruginosa PAO were investigated. L-hydroxyproline when present in the growth medium induces all the four enzymes in the pathway. Growth
of the cells in L-proline also weakly induced the enzymes. The organism failed to utilize D-allo-hydroxyproline due to permeability
factors. Mutants blocked in the oxidative pathway of L-hydroxyproline were isolated and enzymatically characterized. In all
the mutants lacking any one of enzymes of the metabolic pathway, L-hydroxyproline is still active in inducing the remaining
enzymes of the pathway suggesting that L-hydroxyproline has intrinsic inducer activity. 相似文献
4.
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
5.
Yoshihiko Uratani Tomofusa Tsuchiya Yukiko Akamatsu Toshimitsu Hoshino 《The Journal of membrane biology》1989,107(1):57-62
Summary A transport system for branched-chain amino acids (designated as LIV-II system) inPseudomonas aeruginosa requires Na+ for its operation. Coupling cation for this system was identified by measuring cation movement during substrate entry using cation-selective electrodes. Uptakes of Na+ and Li– were induced by the imposition of an inwardly-directed concentration gradient of leucine, isoleucine, or valine. No uptake of H– was found, however, under the same conditions. In addition, effects of Na+ and Li+ on the kinetic property of the system were examined. At chloride salt concentration of 2.5mm, values of apparentK
m andV
max for leucine uptake were larger in the presence of Na+ than Li+. These results indicate that the LIV-II transport system is a Na+(Li+)/substrate cotransport system, although effects of Na+ and Li+ on kinetics of the system are different. 相似文献
6.
Thomas Jahns Alexandra Zobel Diethelm Kleiner Heinrich Kaltwasser 《Archives of microbiology》1988,149(5):377-383
Evidence for the existence of an energy-dependent urea permease was found for Alcaligenes eutrophus H16 and Klebsiella pneumoniae M5a1 by studying uptake of 14C-urea. Since intracellular urea was metabolized immediately, uptake did not result in formation of an urea pool. Evidence is based on observations that the in vivo urea uptake and in vitro urease activity differ significantly with respect to kinetic parameters, temperature optimum, pH optimum, response towards inhibitors and regulation. The K
m for urea uptake was 15–20 times lower (38 M and 13 M urea for A. eutrophus and K. pneumoniae, respectively) than the K
m of urease for urea (650 M and 280 M urea), the activity optimum for A. eutrophus was at pH 6.0 and 35°C for the uptake and pH 9.0 and 65°C for urease. Uptake but not urease activity in both organisms strongly decreased upon addition of inhibitors of energy metabolism, while in K. pneumoniae, potent inhibitors of urease (thiourea and hydroxyurea) did not affect the uptake process. Significant differences in the uptake rates were observed during growth with different nitrogen sources (ammonia, nitrate, urea) or in the absence of a nitrogen source; this suggested that a carrier is involved which is subject to nitrogen control. Some evidence for the presence of an energy-dependent uptake of urea was also obtained in Pseudomonas aeruginosa DSM 50071 and Providencia rettgeri DSM 1131, but not in Proteus vulgaris DSM 30118 and Bacillus pasteurii DSM 33.Non-standard abbreviations CCCP
Carbonylcyanide-m-chlorphenylhydrazone
- DCCD
dicyclohexylcarbodiimide
- DNP
2,4-dinitrophenole 相似文献
7.
8.
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
9.
Regulation of amidase formation in mutants from Pseudomonas aeruginosa PAO lacking glutamine synthetase activity 总被引:1,自引:0,他引:1
Dick B. Janssen Patricia M. Herst Han M. L. J. Joosten Chris van der Drift 《Archives of microbiology》1982,131(4):344-346
The formation of amidase was studied in mutants from Pseudomonas aeruginosa PAO lacking glutamine synthetase activity. It appeared that catabolite repression of amidase synthesis by succinate was partially relieved when cellular growth was limited by glutamine. Under these conditions, a correlation between amidase and urease formation was observed. The results suggest that amidase formation in strain PAO is subject to nitrogen control and that glutamine or some compound derived from it mediates the nitrogen repression of amidase. 相似文献
10.
Kimiko Watanabe Ken-ichi Noda Yoshinori Ohta Kenji Maruhashi 《Biotechnology letters》2002,24(11):897-903
The dsz desulfurization gene cluster from Rhodococcus erythropolis KA2-5-1 was transferred into the chromosomes of Pseudomonas aeruginosa NCIMB 9571 by using a transposon vector. Resting cells of the recombinant strain, PAR41, desulfurized 63 mg sulfur l–1 of light gas oil (LGO) containing 360 mg S l–1. The desulfurization activity for LGO by the resting cells of strain PAR41 grown with n-tetradecane (50% v/v) was much higher (1018-fold) than in glucose-grown cells. P. aeruginosa NCIMB 9571 is able to take up water-insoluble compounds from an oil phase which is enhanced by n-alkane. 相似文献
11.
Zinc concentrations ranging between 0.1 and 1 mm only slightly reduced maximal growth of wild-type Pseudomonas aeruginosa 7NSK2 in iron-limiting casamino acid medium, but had a clear negative effect on the growth of mutant MPFM1 (pyoverdin negative) and especially mutant KMPCH (pyoverdin and pyochelin negative). Production of pyoverdin by wild-type strain 7NSK2 was significantly increased in the presence of 0.5 mm zinc and could not be repressed by iron even at a concentration of 100 m. Siderophore detection via isoelectrofocusing revealed that mutant KMPCH did not produce any siderophores, while mutant MPFM1 overproduced a siderophore with an acidic isoelectric point, most likely pyochelin. Pyochelin production by MPFM1 was stimulated by the presence of zinc in a similar way as pyoverdin for the wild-type. Analysis of outer membrane proteins revealed that three iron regulated outer membrane proteins (IROMPs) (90, 85 and 75 kDa) were induced by iron deficiency in the wild-type, while mutants were found to have altered IROMP profiles. Zinc specifically enhanced the production of a 85 kDa IROMP in 7NSK2, a 75 kDa IROMP in MPFM1 and a 90 kDa IROMP in KMPCH. 相似文献
12.
13.
M. Sondossi H. W. Rossmoore J. W. Wireman 《Journal of industrial microbiology & biotechnology》1986,1(2):87-96
Summary Evaluation of formaldehyde and fifteen biocides in formaldehyde sensitive (S) and resistant (R) strains ofPseudomonas aeruginosa revealed a pattern of response that allowed a comparison of the mode of action of these biocides. The response of these strains to the various biocides, as well as the induction of transient resistance or cross-resistance in the (S) strain, allowed a grouping of biocides based on this pattern of response. Group 1 biocides acted in a manner indistinguishable from formaldehyde for both the (S) and (R) strains. Group 2 biocides were not effective against either the (S) or (R) strains at concentrations calculated to release equimolar concentrations of formaldehyde. However, treatment of the (S) strain with formaldehyde or Group 2 biocides resulted in the development of cross-resistance. Group 3 biocides were equally effective against the (S) and (R) strain, but the (S) strain survivors of treatment with Group 3 biocides were resistant to formaldehyde. Group 4 biocides (controls) had no presumed connection to formaldehyde mode of action. These four groupings, based on pattern of response, also resulted in groupings of biocides based on chemical structure. 相似文献
14.
Cynthia G. MacElwee Professors Hung Lee Professors Jack T. Trevors 《Journal of industrial microbiology & biotechnology》1990,5(1):25-31
Summary Twenty-three bacterial strains were isolated from oil-contaminated soil samples. Of these, 20 displayed some ability to effect oil dispersion and they were screened quantitatively for the ability to emulsify 0.5% (v/v) reference oil. One strain, identified asPseudomonas aeruginosa UG1, produced extracellular material that emulsified reference oil, hexadecane and 2-methylnaphthalene at concentrations as high as 6% (v/v) in nutrient broth. Emulsification activity increased during a 10 day incubation period at 30°C. The activity was not influenced by pH over the range 5 to 9. The emulsifying agent was precipitated by cold ethanol. The highest emulsifying activity was detected in the extracellular fraction precipitated between 30 and 50% (v/v) ethanol. A linear relationship was observed between emulsifier concentration (mg/ml) and emulsifying activity. Genetic analysis showed that thePseudomonas aeruginosa UG1 strain did not carry extrachromosomal plasmids, suggesting that the gene(s) coding for emulsifying activity was carried on the chromosome. 相似文献
15.
M. A. Manresa J. Bastida M. E. Mercadé M. Robert C. de Andrés M. J. Espuny J. Guinea 《Journal of industrial microbiology & biotechnology》1991,8(2):133-136
Summary Biosurfactant accumulation occurred in the exponential and stationary phases. Production started when the nitrogen level was very low. Surfactant was produced with a diauxic pattern. Rhamnolipid concentration increased as nitrogen levels increased. Maximum product yield (Y
p/x) 2.9 was detected when C/N ratio was 6.6 and specific rate of product formation (p
q) was calculated. The examination of these kinetics parameters such as product yield and specific rate of product formation should be taken into account to develop a high efficient production process. 相似文献
16.
The regulation of amidase synthesis inP. aeruginosa is under positive control. This review describes the experimental evolution of amidase and its regulator protein for the hydrolysis of novel substrates and experiments to elucidate the mechanism of the control system. 相似文献
17.
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
18.
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
19.
Pseudomonas aeruginosa samples were studied using Mössbauer spectroscopy and electron paramagnetic resonance (EPR). Samples included whole cells, membranes, and soluble fractions from cells which had been grown with57ferric chloride,57ferric citrate or incubated with57ferripyoverdine. These experiments show for the first time thatP. aeruginosa can accumulate iron in a bacterioferritin when grown under conditions of iron limitation and incubated with its cognate ferrisiderophore, ferripyoverdine. Soluble fraction fromP. aeruginosa cells which were grown iron starved and incubated with57ferripyoverdine for 120 min showed the presence of both a ferric and ferrous complex whose Mössbauer spectra matched that of bacterioferritin extracted fromAzotobacter vinelandii and whose EPR spectra showed a characteristic ferritin-like resonance. A second soluble fraction sample from cells which had been grown with57ferric citrate also showed the presence of a species with the same EPR and Mössbauer parameters. In addition Western blotting confirmed the presence of bacterioferritin in the soluble fraction of the cells which had been incubated with ferripyoverdine. 相似文献
20.
铜绿假单胞菌铁摄取与生物被膜形成研究进展 总被引:1,自引:0,他引:1
生物被膜是单细胞微生物通过其分泌的胞外多聚基质粘附于介质表面并将其自身包绕其中而成的膜样微生物细胞聚集物。生物被膜的形成使细菌具有更强的适应外界环境的能力,也是导致微生物产生耐药性及慢性感染性疾病难以治疗的重要原因之一。铜绿假单胞菌在肺部的定殖是肺囊性纤维化病患者发病和死亡主要原因,其造成的感染通常与形成抗生素抗性极强的生物被膜有关。铜绿假单胞菌生物被膜的形成受控于多种复杂的细菌调控体系之下,包括群体感应系统及参与调节胞外多聚基质合成的双组分调控系统等。此外,为了利用低浓度的环境铁来维持生存并完成各种生理功能,铜绿假单胞菌进化出了一系列铁摄取系统,这些系统对其毒力因子的释放和生物被膜的形成又起着重要的调控作用。本文主要对铜绿假单胞菌生物被膜的形成与调控机制及其铁摄取系统进行了综述,为进一步了解及清除铜绿假单胞菌引发的问题提供途径与思路。 相似文献