Gram-Negative Bacterial Envelope Homeostasis under Oxidative and Nitrosative Stress

Chautrand, Thibault; Souak, Djouhar; Chevalier, Sylvie; Duclairoir‐Poc, Cécile

doi:10.3390/microorganisms10050924

Cited by 24 publications

(14 citation statements)

References 133 publications

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“…The outer membrane of Gram negative bacteria is asymmetric, where the inner leaflet (facing the periplasm) is composed by phospholipids and the outer layer is formed by glycolipids, including anionic lipopolysaccharides (LPS) 51 . The enhancement of its stability and impermeability is important to endure stress conditions.…”

Section: Discussionmentioning

confidence: 99%

“…The enhancement of its stability and impermeability is important to endure stress conditions. For instance, bacteria such as Salmonella typhimurium modulate outer membrane permeability to overcome the oxidative conditions imposed by H 2 O 2 43,51 . This has led researchers to propose the targeting of membrane integrity as a therapeutic approach 9,52 .…”

Section: Discussionmentioning

confidence: 99%

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Polyamine-mediated mechanisms contribute to oxidative stress tolerance in Pseudomonas syringae

Solmi

Rossi

Romero

et al. 2023

Sci Rep

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Bacterial phytopathogens living on the surface or within plant tissues may experience oxidative stress because of the triggered plant defense responses. Although it has been suggested that polyamines can defend bacteria from this stress, the mechanism behind this action is not entirely understood. In this study, we investigated the effects of oxidative stress on the polyamine homeostasis of the plant pathogen Pseudomonas syringae and the functions of these compounds in bacterial stress tolerance. We demonstrated that bacteria respond to H2O2 by increasing the external levels of the polyamine putrescine while maintaining the inner concentrations of this compound as well as the analogue amine spermidine. In line with this, adding exogenous putrescine to media increased bacterial tolerance to H2O2. Deletion of arginine decarboxylase (speA) and ornithine decarboxylate (speC), prevented the synthesis of putrescine and augmented susceptibility to H2O2, whereas targeting spermidine synthesis alone through deletion of spermidine synthase (speE) increased the level of extracellular putrescine and enhanced H2O2 tolerance. Further research demonstrated that the increased tolerance of the ΔspeE mutant correlated with higher expression of H2O2-degrading catalases and enhanced outer cell membrane stability. Thus, this work demonstrates previously unrecognized connections between bacterial defense mechanisms against oxidative stress and the polyamine metabolism.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Polyamine-mediated mechanisms contribute to oxidative stress tolerance in Pseudomonas syringae

Solmi

Rossi

Romero

et al. 2023

Sci Rep

View full text Add to dashboard Cite

show abstract

“…The enhancement of its stability and impermeability is important to endure stress conditions. For instance, bacteria such as Salmonella typhimurium modulate outer membrane permeability to overcome the oxidative conditions imposed by H 2 O 2 41,49 . This has led researchers to propose the targeting of membrane integrity as a therapeutic approach 9,50 .…”

Section: Discussionmentioning

confidence: 99%

“…The outer membrane of Gram negative bacteria is asymmetric, where the inner lea et (facing the periplasm) is composed by phospholipids and the outer layer is formed by glycolipids, including anionic lipopolysaccharides (LPS) 49 . The enhancement of its stability and impermeability is important to endure stress conditions.…”

Section: Discussionmentioning

confidence: 99%

Polyamine-mediated mechanisms contribute to oxidative stress tolerance in Pseudomonas syringae.

Solmi

Rossi

Romero

et al. 2023

Preprint

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Bacterial phytopathogens thriving in the surface or the interior of plants may experience oxidative stress because of the activation of plant defense responses. Polyamines have been proposed to participate in the protection of bacteria against this stress, but the mechanisms behind their functions are mostly unclear. In this study, we sought to understand the effects of oxidative stress on the polyamine homeostasis of the plant pathogen Pseudomonas syringae and decipher the functions of these compounds in stress tolerance. We showed that bacteria react to H2O2 by raising the extracellular amount of the polyamine putrescine while the intracellular levels of this compound as well as the analogue spermidine remained unchanged. Consistent with this, supplementation of media with exogenous putrescine enhanced bacterial tolerance to H2O2. Deletion of arginine decarboxylase (speA) and ornithine decarboxylate (speC), prevented the synthesis of putrescine and augmented susceptibility to H2O2, whereas targeting spermidine synthesis alone through deletion of spermidine synthase (speE) increased the level of extracellular putrescine and enhanced H2O2 tolerance. Further research demonstrated that the increased tolerance of the ΔspeE mutant correlated both with increased expression of H2O2-degrading catalases and enhanced outer cell membrane stability. Thus, this work demonstrates previously unidentified links between the metabolism of polyamines and the defense against oxidative stress in bacteria.

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“…Nitrosative stress caused by an increase in reactive nitrogen species (RNS) ( Chautrand et al, 2022 ) is another important stressor during the biodegradation of nitrogen-containing compounds. The main source of RNS is nitric oxide produced by microbial cells during the degradation process.…”

Section: Crosstalk Between Oxidative and Other Stressesmentioning

confidence: 99%

Adaptive Response of Thermophiles to Redox Stress and Their Role in the Process of dye Degradation From Textile Industry Wastewater

2022

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Release of dye-containing textile wastewater into the environment causes severe pollution with serious consequences on aquatic life. Bioremediation of dyes using thermophilic microorganisms has recently attracted attention over conventional treatment techniques. Thermophiles have the natural ability to survive under extreme environmental conditions, including high dye concentration, because they possess stress response adaptation and regulation mechanisms. Therefore, dye detoxification by thermophiles could offer enormous opportunities for bioremediation at elevated temperatures. In addition, the processes of degradation generate reactive oxygen species (ROS) and subject cells to oxidative stress. However, thermophiles exhibit better adaptation to resist the effects of oxidative stress. Some of the major adaptation mechanisms of thermophiles include macromolecule repair system; enzymes such as superoxide dismutase, catalase, and glutathione peroxidase; and non-enzymatic antioxidants like extracellular polymeric substance (EPSs), polyhydroxyalkanoates (PHAs), etc. In addition, different bacteria also possess enzymes that are directly involved in dye degradation such as azoreductase, laccase, and peroxidase. Therefore, through these processes, dyes are first degraded into smaller intermediate products finally releasing products that are non-toxic or of low toxicity. In this review, we discuss the sources of oxidative stress in thermophiles, the adaptive response of thermophiles to redox stress and their roles in dye removal, and the regulation and crosstalk between responses to oxidative stress.

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Gram-Negative Bacterial Envelope Homeostasis under Oxidative and Nitrosative Stress

Cited by 24 publications

References 133 publications

Polyamine-mediated mechanisms contribute to oxidative stress tolerance in Pseudomonas syringae

Polyamine-mediated mechanisms contribute to oxidative stress tolerance in Pseudomonas syringae

Polyamine-mediated mechanisms contribute to oxidative stress tolerance in Pseudomonas syringae.

Adaptive Response of Thermophiles to Redox Stress and Their Role in the Process of dye Degradation From Textile Industry Wastewater

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