Genome-wide transcriptional response to silver stress in extremely halophilic archaeon Haloferax alexandrinus DSM 27206.

Background: The extremely halophilic archaeon Haloferax (Hfx.) alexandrinus DSM 27206 was previously documented for the ability to biosynthesize silver nanoparticles while mechanisms underlying its silver tolerance were overlooked. In the current study, we aimed to assess the transcriptional response of this haloarchaeon to varying concentrations of silver, seeking a comprehensive understanding of the molecular determinants underpinning its heavy metal tolerance.

Physiological response to silver toxicity in the extremely halophilic archaeon Halomicrobium mukohataei.

Adaptive strategies responsible for heavy metal tolerance were explored in the extremely halophilic archaeon Halomicrobium mukohataei DSM 12286. The tested strain was seemingly able to overcome silver-induced oxidative stress (assessed by malondialdehyde quantification, catalase assay and total antioxidant capacity measurement) mainly through non-enzymatic antioxidants. Energy dispersive spectrometry analysis illustrated the presence of colloidal silver in Hmc.

The impact of cation concentration on Microcystis (cyanobacteria) scum formation.

Cyanobacterial scums at the surface of the lakes are potentially harmful phenomena with increasing occurrence in the last decades, and the causes that lead to their formation are still an unresolved issue. In order to better understand what triggers the scums, we investigated the effect of several Mg and Ca ion concentrations in promoting them in eight Microcystis aeruginosa strains. The possibility to prevent scum formation by using the ion chelator EDTA was also explored.