Could Life Have Started on Mars? Planetary Conditions That Assemble and Destroy Protocells.

Early Mars was likely habitable, but could life actually have started there? While cellular life emerged from prebiotic chemistry through a pre-Darwinian selection process relevant to both Earth and Mars, each planet posed unique selection 'hurdles' to this process. We focus on drivers of selection in prebiotic chemistry generic to Earth-like worlds and specific to Mars, such as an iron-rich surface. Iron, calcium, and magnesium cations are abundant in hydrothermal settings on Earth and Mars, a promising environment for an origin of life. We investigated the impact of cations on the stability and disruption of different primitive cell membranes under different pH conditions. The relative destabilizing effect of cations on membranes observed in this study is Ca2+ > Fe2+ > Mg2+. Cation concentrations in Earth systems today are too low to disrupt primitive membranes, but on Mars concentrations could have been elevated enough to disrupt membranes during surface dehydration. Membranes and RNA interact during dehydration-rehydration cycles to mutually stabilize each other in cation-rich solutions, and optimal membrane composition can be 'selected' by environmental factors such as pH and cation concentrations. We introduce an approach that considers how life may have evolved differently under the Martian planetary conditions and selective pressures.

Bridging Place-Based Astrobiology Education with Genomics, Including Descriptions of Three Novel Bacterial Species Isolated from Mars Analog Sites of Cultural Relevance.

Democratizing genomic data science, including bioinformatics, can diversify the STEM workforce and may, in turn, bring new perspectives into the space sciences. In this respect, the development of education and research programs that bridge genome science with "place" and world-views specific to a given region are valuable for Indigenous students and educators. Through a multi-institutional collaboration, we developed an ongoing education program and model that includes Illumina and Oxford Nanopore sequencing, free bioinformatic platforms, and teacher training workshops to address our research and education goals through a place-based science education lens. High school students and researchers cultivated, sequenced, assembled, and annotated the genomes of 13 bacteria from Mars analog sites with cultural relevance, 10 of which were novel species. Students, teachers, and community members assisted with the discovery of new, potentially chemolithotrophic bacteria relevant to astrobiology. This joint education-research program also led to the discovery of species from Mars analog sites capable of producing N-acyl homoserine lactones, which are quorum-sensing molecules used in bacterial communication. Whole genome sequencing was completed in high school classrooms, and connected students to funded space research, increased research output, and provided culturally relevant, place-based science education, with participants naming three novel species described here. Students at St. Andrew's School (Honolulu, Hawai'i) proposed the name Bradyrhizobium prioritasuperba for the type strain, BL16AT, of the new species (DSM 112479T = NCTC 14602T). The nonprofit organization Kauluakalana proposed the name Brenneria ulupoensis for the type strain, K61T, of the new species (DSM 116657T = LMG = 33184T), and Hawai'i Baptist Academy students proposed the name Paraflavitalea speifideiaquila for the type strain, BL16ET, of the new species (DSM 112478T = NCTC 14603T).

Metabolic versatility of Caldarchaeales from geothermal features of Hawai'i and Chile as revealed by five metagenome-assembled genomes.

Members of the archaeal order Caldarchaeales (previously the phylum Aigarchaeota) are poorly sampled and are represented in public databases by relatively few genomes. Additional representative genomes will help resolve their placement among all known members of Archaea and provide insights into their roles in the environment. In this study, we analyzed 16S rRNA gene amplicons belonging to the Caldarchaeales that are available in public databases, which demonstrated that archaea of the order Caldarchaeales are diverse, widespread, and most abundant in geothermal habitats. We also constructed five metagenome-assembled genomes (MAGs) of Caldarchaeales from two geothermal features to investigate their metabolic potential and phylogenomic position in the domain Archaea. Two of the MAGs were assembled from microbial community DNA extracted from fumarolic lava rocks from Mauna Ulu, Hawai'i, and three were assembled from DNA obtained from hot spring sinters from the El Tatio geothermal field in Chile. MAGs from Hawai'i are high quality bins with completeness >95% and contamination <1%, and one likely belongs to a novel species in a new genus recently discovered at a submarine volcano off New Zealand. MAGs from Chile have lower completeness levels ranging from 27 to 70%. Gene content of the MAGs revealed that these members of Caldarchaeales are likely metabolically versatile and exhibit the potential for both chemoorganotrophic and chemolithotrophic lifestyles. The wide array of metabolic capabilities exhibited by these members of Caldarchaeales might help them thrive under diverse harsh environmental conditions. All the MAGs except one from Chile harbor putative prophage regions encoding several auxiliary metabolic genes (AMGs) that may confer a fitness advantage on their Caldarchaeales hosts by increasing their metabolic potential and make them better adapted to new environmental conditions. Phylogenomic analysis of the five MAGs and over 3,000 representative archaeal genomes showed the order Caldarchaeales forms a monophyletic group that is sister to the clade comprising the orders Geothermarchaeales (previously Candidatus Geothermarchaeota), Conexivisphaerales and Nitrososphaerales (formerly known as Thaumarchaeota), supporting the status of Caldarchaeales members as a clade distinct from the Thaumarchaeota.

Chitinophaga pendula, sp. nov., from an air conditioner condensate drain line.

A Gram-negative, rod-shaped and filamentous bacterium designated MD30BT was isolated from a biofilm hanging in water flowing from an air conditioner condensate drain line in Honolulu, Hawai'i. Based on 1517 nucleotides of the strain's 16S rRNA gene, its nearest neighbours are Chitinophaga rhizosphaerae T16R-86T (96.7 %), Chitinophaga caseinilytica S-52T (96.6 %), Chitinophaga lutea ZY74T (96.6 %), Chitinophaga niabensis JS13-10T (96.6 %) and Chitinophaga ginsengisoli Gsoil 052T (96.5 %). MD30BT cells are non-motile, strictly aerobic, and catalase and oxidase positive. Growth occurs between 10 and 45 °C. Major fatty acids in whole cells of MD30BT are 13-methyl tetradecanoic acid (34.1 %), cis-11-hexadecenoic acid (30.3 %), and 3-hydroxy, 15-methyl hexadecanoic acid (13.3 %). The quinone system contains predominantly menaquinone MK-7. The polar lipid profile contains the major lipids phosphatidylethanolamine, one unidentified lipid lacking a functional group, and two unidentified aminolipids. sym-Homospermidine is the major polyamine. The G+C content of the genome is 47.58 mol%. Based on phenotypic and genotypic differences between MD30BT and extant species in the Chitinophaga, we propose that MD30BT represents a new Chitinophaga species, for which the name Chitinophaga pendula sp. nov. is proposed to accommodate strain MD30BT as the type strain (DSM 112477T=NCTC 14606T).

Islands Within Islands: Bacterial Phylogenetic Structure and Consortia in Hawaiian Lava Caves and Fumaroles.

Lava caves, tubes, and fumaroles in Hawai'i present a range of volcanic, oligotrophic environments from different lava flows and host unexpectedly high levels of bacterial diversity. These features provide an opportunity to study the ecological drivers that structure bacterial community diversity and assemblies in volcanic ecosystems and compare the older, more stable environments of lava tubes, to the more variable and extreme conditions of younger, geothermally active caves and fumaroles. Using 16S rRNA amplicon-based sequencing methods, we investigated the phylogenetic distinctness and diversity and identified microbial interactions and consortia through co-occurrence networks in 70 samples from lava tubes, geothermal lava caves, and fumaroles on the island of Hawai'i. Our data illustrate that lava caves and geothermal sites harbor unique microbial communities, with very little overlap between caves or sites. We also found that older lava tubes (500-800 yrs old) hosted greater phylogenetic diversity (Faith's PD) than sites that were either geothermally active or younger (<400 yrs old). Geothermally active sites had a greater number of interactions and complexity than lava tubes. Average phylogenetic distinctness, a measure of the phylogenetic relatedness of a community, was higher than would be expected if communities were structured at random. This suggests that bacterial communities of Hawaiian volcanic environments are phylogenetically over-dispersed and that competitive exclusion is the main driver in structuring these communities. This was supported by network analyses that found that taxa (Class level) co-occurred with more distantly related organisms than close relatives, particularly in geothermal sites. Network "hubs" (taxa of potentially higher ecological importance) were not the most abundant taxa in either geothermal sites or lava tubes and were identified as unknown families or genera of the phyla, Chloroflexi and Acidobacteria. These results highlight the need for further study on the ecological role of microbes in caves through targeted culturing methods, metagenomics, and long-read sequence technologies.

Genome Sequence of Arthrobacter globiformis Phage KeAlii from Hawai'i.

Here, we report the genome sequence of bacteriophage KeAlii, a Siphoviridae that infects Arthrobacter globiformis strain B-2979, from Honolulu, Hawai'i. The 41,850-bp genome contains 66 predicted protein-coding genes and 1 gene that encodes a tRNA for tryptophan. Genome comparisons suggest KeAlii is closely related to actinobacteriophage Adolin.

Rheinheimera salexigens sp. nov., isolated from a fishing hook, and emended description of the genus Rheinheimera.

A Gram-negative, rod-shaped bacterium, designated KH87T, was isolated from a fishing hook that had been baited and suspended in seawater off O'ahu, Hawai'i. Based on a comparison of 1524 nt of the 16S rRNA gene sequence of strain KH87T, its nearest neighbours were the GammaproteobacteriaRheinheimera nanhaiensis E407-8T (96.2 % identity), Rheinheimera chironomi K19414T (96.0 %), Rheinheimera pacifica KMM 1406T (95.8 %), Rheinheimera muenzenbergensis E49T (95.7 %), Alishewanella solinquinati KMK6T (94.9 %) and Arsukibacterium ikkense GCM72T (94.6 %). Cells of KH87T were motile by a single polar flagellum, strictly aerobic, and catalase- and oxidase-positive. Growth occurred between 4 and 39 °C, and in a circumneutral pH range. Major fatty acids in whole cells of strain KH87T were cis-9-hexadecenoic acid, hexadecanoic acid and cis-11-octadecenoic acid. The quinone system contained mostly menaquinone MK-7, and a minor amount of ubiquinone Q-8. The polar lipid profile contained the major lipids phosphatidylglycerol, phosphatidylserine, phosphatidylethanolamine, an unidentified aminolipid, and a lipid not containing phosphate, an amino group or a sugar moiety. Putrescine was the major polyamine. Physiological, biochemical and genomic data, including obligate halophily, absence of amylolytic activity, a quinone system dominated by MK-7 and DNA G+C content (42.0 mol%) distinguished KH87T from extant Rheinheimera species; strain KH87T was also distinguished by a multi-locus sequence analysis of aligned and concatenated 16S rRNA, gyrB, rpoB and rpoD gene sequences. Based on phenotypic and genotypic differences, the species Rheinheimera salexigens sp. nov. is proposed to accommodate KH87T as the type strain (=ATCC BAA-2715T=CIP 111115T). An emended description of the genus Rheinheimera is also proposed.

Spatial transcriptomes within the Pseudomonas aeruginosa biofilm architecture.

Bacterial cooperative associations and dynamics in biofilm microenvironments are of special interest in recent years. Knowledge of localized gene-expression and corresponding bacterial behaviors within the biofilm architecture at a global scale has been limited, due to a lack of robust technology to study limited number of cells in stratified layers of biofilms. With our recent pioneering developments in single bacterial cell transcriptomic analysis technology, we generated herein an unprecedented spatial transcriptome map of the mature in vitro Pseudomonas aeruginosa biofilm model, revealing contemporaneous yet altered bacterial behaviors at different layers within the biofilm architecture (i.e., surface, middle and interior of the biofilm). Many genes encoding unknown functions were highly expressed at the biofilm-solid interphase, exposing a critical gap in the knowledge of their activities that may be unique to this interior niche. Several genes of unknown functions are critical for biofilm formation. The in vivo importance of these unknown proteins was validated in invertebrate (fruit fly) and vertebrate (mouse) models. We envisage the future value of this report to the community, in aiding the further pathophysiological understanding of P. aeruginosa biofilms. Our approach will open doors to the study of bacterial functional genomics of different species in numerous settings.

Draft Genome Sequence of a Novel Chitinophaga sp. Strain, MD30, Isolated from a Biofilm in an Air Conditioner Condensate Pipe.

Most of the 24 known Chitinophaga species were originally isolated from soils. We report the draft genome sequence of a putatively novel Chitinophaga sp. from a biofilm in an air conditioner condensate pipe. The genome comprises 7,661,303 bp in one scaffold, 5,694 predicted protein-coding sequences, and a G+C content of 47.6%.

Quantitative and time-course analysis of microbial degradation of 1H,1H,2H,2H,8H,8H-perfluorododecanol in activated sludge.

A methylene group in the fluorinated carbon backbone of 1H,1H,2H,2H,8H,8H-perfluorododecanol (degradable telomer fluoroalcohol, DTFA) renders the molecule cleavable by microbial degradation into two fluorinated carboxylic acids. Several biodegradation products of DTFA are known, but their rates of conversion and fates in the environment have not been determined. We used liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS) to quantitatively investigate DTFA biodegradation by the microbial community in activated sludge in polyethylene terephthalate (PET) flasks, which we also determined here showed least adsorption of DTFA. A reduction in DTFA concentration in the medium was accompanied by rapid increases in the concentrations of 2H,2H,8H,8H-perfluorododecanoic acid (2H,2H,8H,8H-PFDoA), 2H,8H,8H-2-perfluorododecenoic acid (2H,8H,8H-2-PFUDoA), and 2H,2H,8H-7-perfluorododecenoic acid and 2H,2H,8H-8-perfluorododecenoic acid (2H,2H,8H-7-PFUDoA/2H,2H,8H-8-PFUDoA), which were in turn followed by an increase in 6H,6H-perfluorodecanoic acid (6H,6H-PFDeA) concentration, and decreases in 2H,2H,8H,8H-PFDoA, 2H,8H,8H-2-PFUDoA, and 2H,2H,8H-7-PFUDoA/2H,2H,8H-8-PFUDoA concentrations. Accumulation of perfluorobutanoic acid (PFBA), a presumed end product of DTFA degradation, was also detected. Our quantitative and time-course study of the concentrations of these compounds reveals main routes of DTFA biodegradation, and the presence of new biodegradation pathways.

Pseudoalteromonas piratica sp. nov., a budding, prosthecate bacterium from diseased Montipora capitata, and emended description of the genus Pseudoalteromonas.

A Gram-stain-negative, motile, rod-shaped bacterium designated OCN003T was cultivated from mucus taken from a diseased colony of the coral Montipora capitata in Kane'ohe Bay, O'ahu, Hawai'i. Colonies of OCN003T were pale yellow, 1-3 mm in diameter, convex, smooth and entire. The strain was heterotrophic, strictly aerobic and strictly halophilic. Cells of OCN003T produced buds on peritrichous prosthecae. Growth occurred within the pH range of 5.5 to 10, and the temperature range of 14 to 39 °C. Major fatty acids were 16 : 1ω7c, 16 : 0, 18 : 1ω7c, 17 : 1ω8c, 12 : 0 3-OH and 17 : 0. Phylogenetic analysis of 1399 nucleotides of the 16S rRNA gene nucleotide sequence and a multi-locus sequence analysis of three genes placed OCN003T in the genus Pseudoalteromonas and indicated that the nearest relatives described are Pseudoalteromonas spongiae, P. luteoviolacea, P. ruthenica and P. phenolica(97-99 % sequence identity). The DNA G+C content of the strain's genome was 40.0 mol%. Based on in silico DNA-DNA hybridization and phenotypic differences from related type strains, we propose that OCN003T represents the type strain of a novel species in the genus Pseudoalteromonas, proposed as Pseudoalteromonas piratica sp. nov. OCN003T (=CCOS1042T=CIP 111189T). An emended description of the genus Pseudoalteromonas is presented.

Genome Sequence of Rheinheimera salexigens sp. nov. Isolated from a Fishing Hook off O'ahu, Hawai'i.

Rheinheimera salexigens KH87T is an obligately halophilic gammaproteobacterium. The strain's draft genome sequence, generated by the Roche 454 GS FLX+ platform, comprises two scaffolds of ~3.4 Mbp and ~3 kbp, with 3,030 protein-coding sequences and 58 tRNA coding regions. The G+C content is 42 mol%.

Draft Genome Sequence of a Novel Marinobacter sp. Strain from Honolulu Harbor, Hawai'i.

Marinobacter sp. strain X15-166BT was cultivated from sediment in Honolulu Harbor, Hawai'i. The X15-166BT draft genome of 3,490,661 bp encodes 3,115 protein-coding open reading frames. We anticipate that the genome will provide insights into the strain's lifestyle and the evolution of Marinobacter.

Draft Genome Sequence of Terasakiispira papahanaumokuakeensis PH27AT, a Spiral Bacterium from the Northwestern Hawaiian Islands.

The genus Terasakiispira hosts only Terasakiispira papahanaumokuakeensis PH27AT, cultivated from an anchialine pond on Pearl and Hermes Atoll, Northwestern Hawaiian Islands. The strain's genome sequence may provide insights into the evolution of free-living Oceanospirillaceae.

Draft Genome Sequence of a Novel Luteimonas sp. Strain from Coral Mucus, Hawai'i.

Luteimonas sp. strain JM171 was cultivated from mucus collected around the coral Porites lobata The JM171 draft genome of 2,992,353 bp contains 2,672 protein-coding open reading frames, 45 tRNA coding regions, and encodes a putative globin-coupled diguanylate cyclase, JmGReg.

Draft Genome Sequence of Piscirickettsia litoralis, Isolated from Seawater.

One species of Piscirickettsia, a pathogen of salmonid fish, has been described. The genome sequence of a putative second and free-living species may provide insights into the evolution of pathogenicity in the genus.

Genome Sequence of Flavobacterium akiainvivens IK-1T, Isolated from Decaying Wikstroemia oahuensis, an Endemic Hawaiian Shrub.

Flavobacterium spp. have been cultivated from diverse aquatic and terrestrial habitats. F. akiainvivens IK-1(T) was cultivated from decaying wood of Wikstroemia oahuensis, an endemic Hawaiian shrub. The strain's genome sequence may provide insights into niche adaptation and evolution of the genus in a mid-ocean archipelago.

Terasakiispira papahanaumokuakeensis gen. nov., sp. nov., a gammaproteobacterium from Pearl and Hermes Atoll, Northwestern Hawaiian Islands.

A Gram-negative, helical bacterium designated PH27AT was cultivated from an anchialine pool on Pearl and Hermes Atoll, Northwestern Hawaiian Islands. The obligately halophilic strain was motile by bipolar tufts of flagella and grew optimally at pH 7, and microaerobically or aerobically. Closest neighbours based on 16S rRNA gene nucleotide sequence identity are Marinospirillum celere v1c_Sn-redT (93.31 %) and M. alkaliphilum Z4T (92.10 %) in the family Oceanospirillaceae, class Gammaproteobacteria. PH27AT is distinguished phenotypically from members of the genus Marinospirillum by its hydrolysis of gelatin, the absence of growth in media containing ≤ 1 % (w/v) NaCl and the ranges of temperature (12­40 °C) and pH (5­8) for growth. The major compound ubiquinone Q-9 distinguishes the quinone system of strain PH27AT from those in members of the genus Marinospirillum and other members of the Oceanospirillaceae, in which the major quinone is Q-8. Major polar lipids in PH27AT were phosphatidylethanolamine and phosphatidylglycerol, with moderate amounts of diphosphatidylglycerol and phosphatidylserine. Spermidine and cadaverine dominated the polyamine pattern; large proportions of cadaverine have not been reported in members of the genus Marinospirillum. Genotypic and chemotaxonomic data show that PH27AT does not belong in the genus Marinospirillum or other genera of the family Oceanospirillaceae or the Halomonadaceae. We propose a new genus, Terasakiispira gen. nov., be created to accommodate Terasakiispira papahanaumokuakeensis gen. nov., sp. nov. as the type species, with PH27AT ( = ATCC BAA-995T = DSM 16455T = DSM 23961T) as the type strain.

Draft Genome Sequence of Pantoea anthophila Strain 11-2 from Hypersaline Lake Laysan, Hawaii.

Most Pantoea spp. have been isolated from plant sources or clinical samples. However, we cultivated Pantoea anthophila 11-2 from hypersaline water from the lake on Laysan, Northwestern Hawaiian Islands. Draft genome sequencing of 11-2 provides a molecular basis for studies in evolution and pathogenicity in Pantoea spp.

Cultivation and complete genome sequencing of Gloeobacter kilaueensis sp. nov., from a lava cave in Kilauea Caldera, Hawai'i.

The ancestor of Gloeobacter violaceus PCC 7421(T) is believed to have diverged from that of all known cyanobacteria before the evolution of thylakoid membranes and plant plastids. The long and largely independent evolutionary history of G. violaceus presents an organism retaining ancestral features of early oxygenic photoautotrophs, and in whom cyanobacteria evolution can be investigated. No other Gloeobacter species has been described since the genus was established in 1974 (Rippka et al., Arch Microbiol 100:435). Gloeobacter affiliated ribosomal gene sequences have been reported in environmental DNA libraries, but only the type strain's genome has been sequenced. However, we report here the cultivation of a new Gloeobacter species, G. kilaueensis JS1(T), from an epilithic biofilm in a lava cave in Kilauea Caldera, Hawai'i. The strain's genome was sequenced from an enriched culture resembling a low-complexity metagenomic sample, using 9 kb paired-end 454 pyrosequences and 400 bp paired-end Illumina reads. The JS1(T) and G. violaceus PCC 7421(T) genomes have little gene synteny despite sharing 2842 orthologous genes; comparing the genomes shows they do not belong to the same species. Our results support establishing a new species to accommodate JS1(T), for which we propose the name Gloeobacter kilaueensis sp. nov. Strain JS1(T) has been deposited in the American Type Culture Collection (BAA-2537), the Scottish Marine Institute's Culture Collection of Algae and Protozoa (CCAP 1431/1), and the Belgian Coordinated Collections of Microorganisms (ULC0316). The G. kilaueensis holotype has been deposited in the Algal Collection of the US National Herbarium (US# 217948). The JS1(T) genome sequence has been deposited in GenBank under accession number CP003587. The G+C content of the genome is 60.54 mol%. The complete genome sequence of G. kilaueensis JS1(T) may further understanding of cyanobacteria evolution, and the shift from anoxygenic to oxygenic photosynthesis.