The waterbodies of the halo-volcanic Dallol complex: earth analogs to guide us, where to look for life in the universe.

Microbes are the Earth life forms that have the highest degree of adaptability to survive, live, or even proliferate in very hostile environments. It is even stated that microbes can cope with any extreme physico-chemical condition and are, therefore, omnipresent all over the Earth: on all the continents, inside its crust and in all its waterbodies. However, our study suggests that there exists areas and even water rich environments on Earth where no life is possible.

Phenotypic and Genetic Characterization of Temperature-Induced Mutagenesis and Mortality in .

strains display a decreased viability when incubated in rich medium at a temperature of 37°C compared to their normal growth temperature of 30°C, a phenomenon coined "temperature-induced mortality and mutagenesis" (TIMM). To scrutinize this aberrant phenotype further, the contributions of specific inducers and protective agents were determined. Different growth media, including lysogeny broth (LB) and Schatz, and components, including casamino acids, in particular amino acids (proline, cysteine, glycine, glutamine, leucine, histidine and phenylalanine) and ammonium, were found to induce TIMM at 37°C.

DNA-Binding and Transcription Activation by Unphosphorylated Response Regulator AgrR From Involved in Silver Resistance.

Even though silver and silver nanoparticles at low concentrations are considered safe for human health, their steadily increasing use and associated release in nature is not without risk since it may result in the selection of silver-resistant microorganisms, thus impeding the utilization of silver as antimicrobial agent. Furthermore, increased resistance to metals may be accompanied by increased antibiotic resistance. Inactivation of the histidine kinase and concomitant upregulation of the cognate response regulator (RR) of the AgrRS two-component system was previously shown to play an important role in the increased silver resistance of laboratory adapted mutants of .

Spontaneous mutation in the AgrRS two-component regulatory system of Cupriavidus metallidurans results in enhanced silver resistance.

The uncontrolled and widespread use of (nano)silver compounds has led to the increased release of these compounds into the environment, raising concerns about their negative impact on ecosystems. Concomitantly, silver resistance determinants are widely spread among environmental and clinically relevant bacteria although the underlying mechanisms are not yet fully understood. We show that Cupriavidus metallidurans is able to adapt to toxic silver concentrations.

Genomic and Transcriptomic Changes that Mediate Increased Platinum Resistance in Cupriavidus metallidurans.

The extensive anthropogenic use of platinum, a rare element found in low natural abundance in the Earth's continental crust and one of the critical raw materials in the EU innovation partnership framework, has resulted in increased concentrations in surface environments. To minimize its spread and increase its recovery from the environment, biological recovery via different microbial systems is explored. In contrast, studies focusing on the effects of prolonged exposure to Pt are limited.

Unintentional Genomic Changes Endow with an Augmented Heavy-Metal Resistance.

For the past three decades, has been one of the major model organisms for bacterial tolerance to heavy metals. Its type strain CH34 contains at least 24 gene clusters distributed over four replicons, allowing for intricate and multilayered metal responses. To gain organic mercury resistance in CH34, broad-spectrum genes were introduced in a previous work via conjugation of the IncP-1β plasmid pTP6.

Strains with Different Mobilomes and from Distinct Environments Have Comparable Phenomes.

has been mostly studied because of its resistance to numerous heavy metals and is increasingly being recovered from other environments not typified by metal contamination. They host a large and diverse mobile gene pool, next to their native megaplasmids. Here, we used comparative genomics and global metabolic comparison to assess the impact of the mobilome on growth capabilities, nutrient utilization, and sensitivity to chemicals of type strain CH34 and three isolates (NA1, NA4 and H1130).

Paleomicrobiology to investigate copper resistance in bacteria: isolation and description of Cupriavidus necator B9 in the soil of a medieval foundry.

Remains of a medieval foundry were excavated by archaeologists in 2013 in Verdun (France). Ancient workshops specialized in brass and copper alloys were found with an activity between 13th to 16th c. Levels of Cu, Zn and Pb reached 20000, 7000 and 6000 mg kg (dw), respectively, in several soil horizons.

Draft Genome Sequences of Ralstonia pickettii Strains SSH4 and CW2, Isolated from Space Equipment.

Ralstonia pickettii SSH4 and CW2 were isolated from space equipment. Here, we report their draft genome sequences with the aim of gaining insight into their potential to adapt to these environments.

Genome Sequences of Cupriavidus metallidurans Strains NA1, NA4, and NE12, Isolated from Space Equipment.

Cupriavidus metallidurans NA1, NA4, and NE12 were isolated from space and spacecraft-associated environments. Here, we report their draft genome sequences with the aim of gaining insight into their potential to adapt to these environments.

Genome Sequence of Cupriavidus metallidurans Strain H1130, Isolated from an Invasive Human Infection.

Cupriavidus metallidurans H1130 was repeatedly isolated from different blood culture sets taken from a patient suffering from significant nosocomial septicemia. Here, we announce the H1130 genome sequence for use in comparative analyses and for exploring the adaptation and pathogenic potential of this bacterium.

Characterization of culturable Paenibacillus spp. from the snow surface on the high Antarctic Plateau (DOME C) and their dissemination in the Concordia research station.

Culturable psychrotolerant bacteria were isolated from the top snow on the high Antarctic Plateau surrounding the research station Concordia. A total of 80 isolates were recovered, by enrichment cultures, from two different isolation sites (a distant pristine site [75° S 123° E] and a site near the secondary runway of Concordia). All isolates were classified to the genus Paenibacillus by 16S rRNA gene phylogenetic analysis and belonged to two different species (based on threshold of 97 % similarity in 16S rRNA gene sequence).

Variation in genomic islands contribute to genome plasticity in Cupriavidus metallidurans.

Background: Different Cupriavidus metallidurans strains isolated from metal-contaminated and other anthropogenic environments were genotypically and phenotypically compared with C. metallidurans type strain CH34. The latter is well-studied for its resistance to a wide range of metals, which is carried for a substantial part by its two megaplasmids pMOL28 and pMOL30.

Insertion sequence elements in Cupriavidus metallidurans CH34: distribution and role in adaptation.

Cupriavidus metallidurans CH34 is a β-proteobacterium well equipped to cope with harsh environmental conditions such as heavy metal pollution. The strain carries two megaplasmids specialized in the response to heavy metals and a considerable number of genomic islands, transposons and insertion sequence (IS) elements. The latter were characterized in detail in this study, which revealed nine new IS elements totaling to 21 distinct IS elements from 10 different IS families and reaching a total of 57 intact IS copies in CH34.

Engineered endophytic bacteria improve phytoremediation of water-soluble, volatile, organic pollutants.

Phytoremediation of highly water soluble and volatile organic xenobiotics is often inefficient because plants do not completely degrade these compounds through their rhizospheres. This results in phytotoxicity and/or volatilization of chemicals through the leaves, which can cause additional environmental problems. We demonstrate that endophytic bacteria equipped with the appropriate degradation pathway improve the in planta degradation of toluene.