Due to their enhanced reactivity, metal and metal-oxide nanoscale zero-valent iron (nZVI) nanomaterials have been introduced into remediation practice. To ensure that environmental applications of nanomaterials are safe, their possible toxic effects should be described. However, there is still a lack of suitable toxicity tests that address the specific mode of action of nanoparticles, especially for nZVI. This contribution presents a novel approach for monitoring one of the most discussed adverse effects of nanoparticles, i.e., oxidative stress (OS). We optimized and developed an assay based on headspace-SPME-GC-MS analysis that enables the direct determination of volatile oxidative damage products (aldehydes) of lipids and proteins in microbial cultures after exposure to commercial types of nZVI. The method employs PDMS/DVB SPME fibers and pentafluorobenzyl derivatization, and the protocol was successfully tested using representatives of bacteria, fungi, and algae. Six aldehydes, namely, formaldehyde, acrolein, methional, benzaldehyde, glyoxal, and methylglyoxal, were detected in the cultures, and all of them exhibited dose-dependent sigmoidal responses. The presence of methional, which was detected in all cultures except those including an algal strain, documents that nZVI also caused oxidative damage to proteins in addition to lipids. The most sensitive toward nZVI exposure in terms of aldehyde production was the yeast strain Saccharomyces cerevisiae, which had an EC50 value of 0.08 g/L nZVI. To the best of our knowledge, this paper is the first to document the production of aldehydes resulting from lipids and proteins as a result of OS in microorganisms from different kingdoms after exposure to iron nanoparticles.

• Klíčová slova
• Nanomaterial, Oxidative stress, Remediation, SPME, Toxicity assay, Yeast,
• MeSH
• aldehydy farmakologie   MeSH
• Bacteria účinky léků   MeSH
• kovové nanočástice toxicita   MeSH
• lipidy MeSH
• nanostruktury MeSH
• oxidace-redukce MeSH
• oxidační stres fyziologie   MeSH
• testy toxicity MeSH
• železité sloučeniny MeSH
• železo metabolismus   toxicita   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• aldehydy MeSH
• ferric oxide MeSH Prohlížeč
• lipidy MeSH
• methional MeSH Prohlížeč
• železité sloučeniny MeSH
• železo MeSH

Contamination by chloroethenes has a severe negative effect on both the environment and human health. This has prompted intensive remediation activity in recent years, along with research into the efficacy of natural microbial communities for degrading toxic chloroethenes into less harmful compounds. Microbial degradation of chloroethenes can take place either through anaerobic organohalide respiration, where chloroethenes serve as electron acceptors; anaerobic and aerobic metabolic degradation, where chloroethenes are used as electron donors; or anaerobic and aerobic co-metabolic degradation, with chloroethene degradation occurring as a by-product during microbial metabolism of other growth substrates, without energy or carbon benefit. Recent research has focused on optimising these natural processes to serve as effective bioremediation technologies, with particular emphasis on (a) the diversity and role of bacterial groups involved in dechlorination microbial processes, and (b) detection of bacterial enzymes and genes connected with dehalogenation activity. In this review, we summarise the different mechanisms of chloroethene bacterial degradation suitable for bioremediation and provide a list of dechlorinating bacteria. We also provide an up-to-date summary of primers available for detecting functional genes in anaerobic and aerobic bacteria degrading chloroethenes metabolically or co-metabolically.

• Klíčová slova
• Biodegradation, Biological reductive dehalogenation, Cis-1,2-dichloroethene, Co-metabolic degradation, Organohalide respiration, Tetrachloroethene, Trichloroethene, Vinyl chloride,
• MeSH
• aerobní bakterie metabolismus   MeSH
• Bacteria metabolismus   MeSH
• biodegradace * MeSH
• halogenace MeSH
• tetrachlorethylen metabolismus   MeSH
• vinylchlorid metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• tetrachlorethylen MeSH
• vinylchlorid MeSH