Living species are continuously subjected to all extrinsic forms of reactive oxidants and others that are produced endogenously. There is extensive literature on the generation and effects of reactive oxygen species (ROS) in biological processes, both in terms of alteration and their role in cellular signaling and regulatory pathways. Cells produce ROS as a controlled physiological process, but increasing ROS becomes pathological and leads to oxidative stress and disease. The induction of oxidative stress is an imbalance between the production of radical species and the antioxidant defense systems, which can cause damage to cellular biomolecules, including lipids, proteins and DNA. Cellular and biochemical experiments have been complemented in various ways to explain the biological chemistry of ROS oxidants. However, it is often unclear how this translates into chemical reactions involving redox changes. This review addresses this question and includes a robust mechanistic explanation of the chemical reactions of ROS and oxidative stress.

/pdf/the-chemistry-of-reactive-oxygen-species-ros-revisited-541bv2tq6n.pdf

The Chemistry of Reactive Oxygen Species (ROS) Revisited: Outlining Their Role in Biological Macromolecules (DNA, Lipids and Proteins) and Induced Pathologies.

A Specific Oxidative Catastrophe Three different classes of antibiotics induce bacterial cell death by the production of hydroxyl radicals. Hydroxyl radicals are powerful oxidizing agents in living cells and will oxidize the nucleic acid base, guanine, to form 8-oxoguanine, which is potentially mutagenic because it can pair with both cytosine and adenine and form lethal double-strand DNA breaks. Foti et al. (p. 315) discovered that overproduction of the nucleotide sanitizer MutT, which hydrolyzes 8-oxo-dGTP to 8-oxo-dGMP, gives striking protection against cell death. Several antibiotics kill bacteria by causing oxidative damage to guanine nucleotides, which then damage nucleic acids. A detailed understanding of the mechanisms that underlie antibiotic killing is important for the derivation of new classes of antibiotics and clinically useful adjuvants for current antimicrobial therapies. Our efforts to understand why DinB (DNA polymerase IV) overproduction is cytotoxic to Escherichia coli led to the unexpected insight that oxidation of guanine to 8-oxo-guanine in the nucleotide pool underlies much of the cell death caused by both DinB overproduction and bactericidal antibiotics. We propose a model in which the cytotoxicity of beta-lactams and quinolones predominantly results from lethal double-strand DNA breaks caused by incomplete repair of closely spaced 8-oxo-deoxyguanosine lesions, whereas the cytotoxicity of aminoglycosides might additionally result from mistranslation due to the incorporation of 8-oxo-guanine into newly synthesized RNAs.

Oxidation of the Guanine Nucleotide Pool Underlies Cell Death by Bactericidal Antibiotics

Copper Clusters: An Effective Antibacterial for Eradicating Multidrug‐Resistant Bacterial Infection In Vitro and In Vivo

Abstract Mineral–microbe interactions play important roles in environmental change, biogeochemical cycling of elements and formation of ore deposits. Minerals provide both beneficial (physical and chemical protection, nutrients, and energy) and detrimental (toxic substances and oxidative pressure) effects to microbes, resulting in mineral-specific microbial colonization. Microbes impact dissolution, transformation and precipitation of minerals through their activity, resulting in either genetically controlled or metabolism-induced biomineralization. Through these interactions, minerals and microbes co-evolve through Earth history. Mineral–microbe interactions typically occur at microscopic scale but the effect is often manifested at global scale. Despite advances achieved through decades of research, major questions remain. Four areas are identified for future research: integrating mineral and microbial ecology, establishing mineral biosignatures, linking laboratory mechanistic investigation to field observation, and manipulating mineral–microbe interactions for the benefit of humankind.

/pdf/a-critical-review-of-mineral-microbe-interaction-and-co-30yz8gty.pdf

A critical review of mineral–microbe interaction and co-evolution: mechanisms and applications

Use of integrated biomarker response for evaluating antioxidant stress and DNA damage of earthworms (Eisenia fetida) in decabromodiphenyl ethane-contaminated soil.

L.-H. Yung

Papers

The role of reactive oxygen species in the biological activity of antimicrobial agents: An updated mini review.