Suitability of the trans/cis Ratio of Unsaturated Fatty Acids in Pseudomonas putida NCTC 10936 as an Indicator of the Acute Toxicity of Chemicals

Loffhagen, N.; Härtig, Claus; Babel, Wolfgang

doi:10.1006/eesa.2001.2089

Cited by 18 publications

(14 citation statements)

References 31 publications

(24 reference statements)

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“…In the study reported here it has been shown that the previously reported stabilization of ETP of P. putida NCTC 10936, mediated by the conversion of cis to trans fatty acids, 13) is probably induced by a reduction in the fluidity of the cytoplasmic membrane.…”

Section: Discussionsupporting

confidence: 51%

“…This could be the reason for the high sensitivity of the cells' ETP to the uncoupling effect of DNP at 40 C (Table 4). Their resistance could be restored completely within 5 min of lowering the incubation temperature from 40 to 30 C. 13) In this time no changes in the fatty acid composition were observed, but the membrane fluidity could have been decreased immediately. The degree of ordering of the lipids, which enables full resistance to the effects of DNP, was probably reestablished.…”

Section: Discussionmentioning

confidence: 83%

“…The degree of ordering of the lipids, which enables full resistance to the effects of DNP, was probably reestablished. 13) In order to assess the effects of chemically disturbing the order of the lipids, resting cells were incubated with 4-CP. Like other lipohilic chemicals 4-CP (log P ¼ 2:39) should accumulate in the lipid bilayer of the cytoplasmic membrane, while taking a place between the fatty acid side chains.…”

Section: Discussionmentioning

confidence: 99%

“…After this period, both respiration and ATP synthesis of P. putida NCTC 10936 were inhibited strongly by 10 mM 4-CP. 13) Unfortunately, the fluidising effect of 4-CP cannot be reversed as easily as the temperature effect. 4-CP must be removed from the lipid bilayer before the viscosity and, thus, the stability of the ETP can fully recover.…”

Section: Discussionmentioning

confidence: 99%

“…10,11) These changes in the fatty acid composition counteract the fluidizing effects of the lipophilic growth substrates by reducing membrane fluidity. 12) However, the ETP of P. putida NCTC 10936 could be stabilized by the conversion of cis to trans unsaturated fatty acids, 13) which is known to occur, as well as changes in the saturation degree, in several strains of P. putida. [14][15][16][17] This raises the question of whether this too is mediated by adaptive reductions in the fluidity of the cytoplamic membrane.…”

Section: -7)mentioning

confidence: 99%

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Pseudomonas putidaNCTC 10936 Balances Membrane Fluidity in Response to Physical and Chemical Stress by Changing the Saturation Degree and theTrans/cisRatio of Fatty Acids

Loffhagen

Härtig

Babel

2004

Bioscience, Biotechnology, and Biochemistry

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Section: Discussionsupporting

confidence: 51%

Section: Discussionmentioning

confidence: 83%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: -7)mentioning

confidence: 99%

See 3 more Smart Citations

Pseudomonas putidaNCTC 10936 Balances Membrane Fluidity in Response to Physical and Chemical Stress by Changing the Saturation Degree and theTrans/cisRatio of Fatty Acids

Loffhagen

Härtig

Babel

2004

Bioscience, Biotechnology, and Biochemistry

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Use of proteomics and physiological characteristics to elucidate ecotoxic effects of methyl tert‐butyl ether in Pseudomonas putida KT2440

et al. 2003

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Use of proteomics and physiological characteristics to elucidate ecotoxic effects of methyl tert-butyl ether in Pseudomonas putida KT2440We monitored rates of growth, ATP-synthesis, respiration, and death to assess the sensitivity of the model organism Pseudomonas putida KT2440 to methyl tert-butyl ether (MTBE), and its degree of toxicity. The physiological data obtained suggested that the energy conservation system was the most sensitive site. However, with the help of proteomic analysis we obtained further information and deeper insight into the molecular mechanisms involved. This analysis indicated that sensitivity involves oxidative stress since alkylhydroperoxide reductase C (AhpC) and two superoxide dismutases (SodM, SodF) were amplified in the presence of MTBE. Thus, proteomics has major advantages in ecotoxicological investigations where the aims include elucidation of the molecular mechanisms as well as characterization of the ecostress and the potency of the stressor(s).

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Insights into Pseudomonas putida KT2440 response to phenol‐induced stress by quantitative proteomics

Santos¹,

2004

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To gain insight into the global mechanism underlying phenol toxicity and tolerance in bacteria, we have generated a two-dimensional protein reference map and used it to identify variations in protein expression levels in Pseudomonas putida KT2440 following exposure to sub-lethal inhibitory concentrations of this solvent. Inspection of the two-dimensional gel electrophoresis gels revealed that 1 h following sudden cell exposure to two different concentrations of phenol, leading to the inhibition of exponential growth (600 mg/L) or to growth arrest for, at least, 4 h before inhibited growth resumption (800 mg/L), the amount of 68 proteins was increased while the amount of 13 proteins was reduced. The up-regulated proteins include proteins involved in the: (i) oxidative stress response (AhpC, SodB,Tpx and Dsb); (ii) general stress reponse (UspA, HtpG, GrpE and Tig); (iii) energetic metabolism (AcnB, AtpH, Fpr, AceA, NuoE, and MmsA-1); (iv) fatty acid biosynthesis (FabB, AccC-1 and FabBx1); (v) inhibition of cell division (MinD); (vi) cell envelope biosynthesis (LpxC, VacJ, and MurA); (vii) transcription regulation (OmpR and Fur); and (viii) transport of small molecules (TolC, BraC, AotJ, AapJ, FbpA and OprQ). Among the down-regulated proteins are those involved in nucleotide biosynthesis (PurM, PurL, PyrH and Dcd) and cell motility (FliC). The information emerging from this genome expression profiling and the detailed investigation of the biological role of candidate genes, as targets of phenol toxicity or as determinants of phenol resistance in P. putida KT2440, will allow more rationale strategies for developing bacteria with greater solvent tolerance with impact in bioremediation and whole-cell biotransformations in media with organic solvents.

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Suitability of the trans/cis Ratio of Unsaturated Fatty Acids in Pseudomonas putida NCTC 10936 as an Indicator of the Acute Toxicity of Chemicals

Cited by 18 publications

References 31 publications

Pseudomonas putidaNCTC 10936 Balances Membrane Fluidity in Response to Physical and Chemical Stress by Changing the Saturation Degree and theTrans/cisRatio of Fatty Acids

Pseudomonas putidaNCTC 10936 Balances Membrane Fluidity in Response to Physical and Chemical Stress by Changing the Saturation Degree and theTrans/cisRatio of Fatty Acids

Use of proteomics and physiological characteristics to elucidate ecotoxic effects of methyl tert‐butyl ether in Pseudomonas putida KT2440

Insights into Pseudomonas putida KT2440 response to phenol‐induced stress by quantitative proteomics

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