The detection of silica-rich dust particles, as an indication for ongoing hydrothermal activity, and the presence of water and organic molecules in the plume of Enceladus, have made Saturn’s icy moon a hot spot in the search for potential extraterrestrial life. Methanogenic archaea are among the organisms that could potentially thrive under the predicted conditions on Enceladus, considering that both molecular hydrogen (H₂) and methane (CH₄) have been detected in the plume. Here we show that a methanogenic archaeon,Methanothermococcus okinawensis, can produce CH₄under physicochemical conditions extrapolated for Enceladus. Up to 72% carbon dioxide to CH₄conversion is reached at 50 bar in the presence of potential inhibitors. Furthermore, kinetic and thermodynamic computations of low-temperature serpentinization indicate that there may be sufficient H₂gas production to serve as a substrate for CH₄production on Enceladus. We conclude that some of the CH₄detected in the plume of Enceladus might, in principle, be produced by methanogens.

Bioprocesses converting carbon dioxide with molecular hydrogen to methane (CH₄) are currently being developed to enable a transition to a renewable energy production system. In this study, we present a comprehensive physiological and biotechnological examination of 80 methanogenic archaea (methanogens) quantifying growth and CH₄ production kinetics at hyperbaric pressures up to 50 bar with regard to media, macro-, and micro-nutrient supply, specific genomic features, and cell envelope architecture. Our analysis aimed to systematically prioritize high-pressure and high-performance methanogens. We found that the hyperthermophilic methanococci Methanotorris igneus and Methanocaldococcoccus jannaschii are high-pressure CH₄ cell factories. Furthermore, our analysis revealed that high-performance methanogens are covered with an S-layer, and that they harbour the amino acid motif Tyr^α444 Gly^α445 Tyr^α446 in the alpha subunit of the methyl-coenzyme M reductase. Thus, high-pressure biological CH₄ production in pure culture could provide a purposeful route for the transition to a carbon-neutral bioenergy sector.

Polypropylene (PP) random copolymers are an important class of commercial materials that can be tuned for a wide range of different applications. The structure–property relations are mainly discussed in this article focusing on two major influencing factors, the catalyst system and the type and amount of comonomer. Ziegler–Natta (ZN) catalyst systems still dominate the production of polypropylene and todays sixth‐generation ZN catalysts are based on postphthalate donor systems. Metallocene (MC) catalysts offer possibilities to exactly control the microstructure of the polymer even better. Mostly, ethylene is used as comonomer being randomly distributed for up to 7.3 mol% when using ZN catalysts. For single site catalysts, homogenous (single phase) materials can be achieved up to ethylene contents of 20.8 mol%. The incorporated comonomer reduces the crystallization speed and the lamellar thickness of the polymer thus affording soft and highly transparent materials. Random copolymers and terpolymers with higherα‐olefins only play a minor role but offer an additional possibility for property adjustments. PP random copolymers can also be varied in their performance through multistage polymerizations, altering the comonomer content and or the molecular weight in the different polymerization reactors.