Gas chromatography-mass spectrometry data from the Viking Mars mission were misinterpreted in 1976 as showing that martian soils contain no organic molecules, and therefore no life, even though the three life detection experiments delivered by Viking all reported life-positive data under the terms of their experimental design. This mistake has been propagated for a half century, including in textbooks and National Aeronautics and Space Administration-endorsed documents, even though it has been known since 2009 that the martian soils contained perchlorate, perchlorate destroys organic materials in ways that might generate the GC-MS results, and Curiosity in 2013 observed such processes in Gale crater on Mars, as have other rovers since. Anomalies in the propagated misinterpretation, including a contradiction between the “strong martian soil oxidant” hypothesis and quantitative results in the carbon assimilation experiment, were “explained away” in 1976, in some cases by invoking results of experiments that had not yet been done. Today, a scientific back-and-forth is long overdue to develop an understanding of what Viking revealed about the possibility of life on the near surface of Mars. Starting this back-and-forth here, we note how the Viking results are compatible with a soil that contains bacterial autotrophs that respire with stored oxygen on Mars (BARSOOM), a lifestyle adapted to its environment, including sparse resources that drive dormancy, scarce atmospheric oxygen, and a cold and briny fluid only intermittently available, perhaps, when the water-ice fogs seen by Viking indicate that the relative humidity exceeds 100%.

Thermoanaerobacter uzonensis strain AK85 belongs to the Thermoanaerobacter genus, which comprises rod-shaped, Gram-positive, thermophilic, obligate anaerobic bacteria. Members of this genus exhibit unique fermentation qualities, such as prolific ethanol production, and can generate longer-chain alcohols from carbohydrate and amino acid sources. Here we present the draft genome sequence of Thermoanaerobacter uzonensis strain AK85, which was previously isolated from a hot spring in Graensdalur in Southwestern Iceland. The genome was sequenced with a 150 bp paired-end library on a MGISEQ-2000. The assembled genome comprises 2,577,794 bp and a GC ratio of 33.69 %. With an ANI of 96.9 % strain AK85 was determined to be a strain of Thermoanaerobacter uzonensis. Annotation was conducted with Prokka which revealed 41 enzymes related to carbohydrate, amino acid, and carboxylic acid metabolism. The genomic dataset establishes the biotechnological capacity and potential of strain AK85 for the production of alcohols and other bio-manufactured products. Further, the genomic dataset is coupled with a cofactor and substrate analysis of the three detected alcohol dehydrogenases. These enzymes were assessed via a lysate based colorimetric assay with NAD⁺ and NADP⁺. Under these conditions the native alcohol dehydrogenases are able to oxidize long chain primary alcohols such as 1-octanol and benzyl alcohol. The reads and assembled draft genome of AK85 were deposited into SRA and NCBI under Bioproject PRJNA1108289, Genbank JBDHNK000000000, and Biosample SAMN41233939.

One horizon in synthetic biology seeks alternative forms of DNA that store, transcribe, and support the evolution of biological information. Here, hydrogen bond donor and acceptor groups are rearranged within a Watson–Crick geometry to get 12 nucleotides that form 6 independently replicating pairs. Such artificially expanded genetic information systems (AEGIS) support Darwinian evolution in vitro. To move AEGIS into living cells, metabolic pathways are next required to make AEGIS triphosphates economically from their nucleosides, eliminating the need to feed these expensive compounds in growth media. We report that “polyphosphate kinases” can be recruited for such pathways, working with natural diphosphate kinases and engineered nucleoside kinases. This pathway in vitro makes AEGIS triphosphates, including third-generation triphosphates having improved ability to survive in living bacterial cells. In α-32P-labeled forms, produced here for the first time, they were used to study DNA polymerases, finding cases where third-generation AEGIS triphosphates perform better with natural enzymes than second-generation AEGIS triphosphates.