Evidence for early life in Earth’s oldest hydrothermal vent precipitates

Although it is not known when or where life on Earth began, some of the earliest habitable environments may have been submarine-hydrothermal vents. Here we describe putative fossilized microorganisms that are at least 3,770 million and possibly 4,280 million years old in ferruginous sedimentary rocks, interpreted as seafloor-hydrothermal vent-related precipitates, from the Nuvvuagittuq belt in Quebec, Canada. These structures occur as micrometre-scale haematite tubes and filaments with morphologies and mineral assemblages similar to those of filamentous microorganisms from modern hydrothermal vent precipitates and analogous microfossils in younger rocks. The Nuvvuagittuq rocks contain isotopically light carbon in carbonate and carbonaceous material, which occurs as graphitic inclusions in diagenetic carbonate rosettes, apatite blades intergrown among carbonate rosettes and magnetite–haematite granules, and is associated with carbonate in direct contact with the putative microfossils. Collectively, these observations are consistent with an oxidized biomass and provide evidence for biological activity in submarine-hydrothermal environments more than 3,770 million years ago

Effects of copper nanoparticles on oxidative stress genes and their enzyme activities in common carp (Cyprinus carpio)

Copper nanoparticles (Cu-NPs) are becoming increasingly prevalent in the environment due to their wide range of applications, posing potential threats to living organisms. Negative effects of Cu-NP exposure have been confirmed in many fish species, and they include disorders in the expression of oxidative stress genes and the activity of enzymes they encode. Common carp, known for its sensitivity to nanopollutants in water, serves as a valuable model organism for nanoparticle toxicity assessment. This study investigated the effects of specific Cu-NPs – copper nanopowder (Cu-NPs), colloidal copper nanoparticles (Cu), and copper oxide nanoparticles (CuO-NPs) – on gene expression and enzyme activity (GPX, CYP1A, HSP70, SOD, CAT) in C. carpio hatchlings, utilizing molecular biology tools and biochemical analyses. Results showed that Cu increased the expression of the hsp70 gene, Cu-NPs elevated the expression of the cyp1a and hsp70 genes, and CuO increased cyp1a expression. Conversely, sod and cat exhibited reduced expression across all samples (Cu, Cu-NPs, CuO). All Cu forms induced significant ROS accumulation and notable alterations in oxidative stress biomarkers (SOD, CAT, GPX)

The family Gallionellaceae

\ua9 2014 Springer-Verlag Berlin Heidelberg. All rights reserved. The family Gallionellaceae comprises the genus Gallionella with one established type species, Gallionella ferruginea. The phylogenetic position of Gallionellaceae, as determined by 16S-rDNA sequence comparisons, is among the β-proteobacteria. Its phylogenetic neighbors are Methylophilaceae, Nitrosomonadaceae, and Spirillaceae. The family contains gram-negative, chemolithoautotrophic, neutrophilic, and aerobic ferrous iron-oxidizing bacteria with the ability to secrete an extracellular twisted stalk composed of numerous fibers. Gallionellaceae can be found where anaerobic groundwater containing ferrous iron reaches an environment that contains oxygen. Large amounts of stalk material are usually produced; this material attracts iron hydroxides and many trace metals, giving it a brown, macroscopic appearance. The stalk and iron hydroxide masses formed may eventually cause severe clogging of ditches, drinking-water wells, and any other facilities utilizing iron-bearing, anaerobic groundwater. The family is relevant to biotechnological processes, as it can be used to remove ferrous iron when producing drinking water from groundwater