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Early life conditions may influence the gut microbiome and contribute to health status in adulthood. We examined the impact of maternal obesity and/or obesogenic diet on the gut microbiome of mothers (at weaning) and their adult offspring, along with the effects of leptin supplementation during suckling. Three groups of rats were studied: control (C) dams, fed with standard diet (SD); western diet (WD) dams, fed with WD (a high-fat, high-sucrose diet) before gestation and during gestation and lactation; and reversion (REV) dams, fed as WD-dams but with SD during lactation. Offspring were supplemented throughout suckling with leptin/vehicle and weaned on an SD. WD-dams showed lower microbial diversity and an altered microbiome compared to C- and REV-dams, widely normalized by diet improvement during lactation. WD- and REV-offspring (males) displayed lower microbiome diversity and greater dominance compared to C-offspring. Taxonomic group differences (Proteobacteria phylum and Bacteroides, Parasutterella, and Phocea genera) were observed in WD- and REV-offspring. WD-offspring, but not REV-offspring, had a greater abundance of the phylum Firmicutes and Lachnospiraceae family and a lower abundance of the family Tannerellaceae compared to C-offspring. Leptin supplementation led to decreased abundance of the phylum Actinobacteria (family Eggerthellaceae and genera Enterorhabdus and Adlercreutzia (females)), and the genera Lachnospiraceae UCG-008 group, Roseburia and Limosilactobacillus, and increased abundance of the genus Dellaglioa, compared to vehicle-treated groups. Therefore, maternal consumption of an obesogenic diet during the perinatal period results in microbiome changes in dams, alleviated by dietary improvement during lactation. Maternal conditions and leptin supplementation during suckling modestly influenced the microbiome in adulthood, which might partially contribute to the adverse/beneficial effects, respectively, of these conditions on programmed metaboli

Groundwater offers an intriguing blend of distinctive physical and chemical conditions, constituting a challenge for microbial life. In Mallorca, the largest island of Balearic archipelago, harbours a variety of thermal anomalies (i.e., geothermal manifestation where surface aquifers exhibiting temperatures exceeding the regional average). The metagenomes of two aquifers in the centre and southern of the island showed Pseudomonadota to be the most represented phylum when using extracted 16S rRNA gene sequences. However, the microbial structures within and between aquifers were remarkably diverse but similar in their metabolic profiles as revealed by the metagenome-assembled genomes (MAGs) pointing to a prevalence of aerobic chemolithoautotrophic and heterotrophic metabolisms, especially in the Llucmajor aquifer. Also, some evidences of anaerobic lifestyles were detected, which would indicate that these environments either could suffer episodes of oxygen depletion or the anaerobes had been transported from deeper waters. We believe that the local environmental factors (temperature, external inputs or chemistry) seem to be more relevant than the connection and, eventually, transport of microbial cells within the aquifer in determining the highly divergent structures. Notably, most of the reconstructed genomes belonged to undescribed bacterial lineages and from them two high-quality MAGs could be classified as novel taxa named following the rules of the Code for Nomenclature of Prokaryotes Described from Sequence Data (SeqCode). Accordingly, we propose the new species and genus Costitxia debesea gen. nov., sp. nov., affiliated with the novel family Costitxiaceae fam. nov., order Costitxiales ord. nov. and class Costitxiia class. nov.; and the new new species and genus Lloretia debesea gen. nov. sp. nov. affiliated with the novel family Lloretiaceae fam. nov.

Current -omics methods allow the collection of a large amount of information that helps in describing the microbial diversity in nature. Here, and as a result of a culturomic approach that rendered the collection of thousands of isolates from 5 different hypersaline sites (in Spain, USA and New Zealand), we obtained 21 strains that represent two new Salinibacter species. For these species we propose the names Salinibacter pepae sp. nov. and Salinibacter grassmerensis sp. nov. (showing average nucleotide identity (ANI) values < 95.09% and 87.08% with Sal. ruber M31T, respectively). Metabolomics revealed species-specific discriminative profiles. Sal. ruber strains were distinguished by a higher percentage of polyunsaturated fatty acids and specific N-functionalized fatty acids; and Sal. altiplanensis was distinguished by an increased number of glycosylated molecules. Based on sequence characteristics and inferred phenotype of metagenome-assembled genomes (MAGs), we describe two new members of the genus Salinibacter. These species dominated in different sites and always coexisted with Sal. ruber and Sal. pepae. Based on the MAGs from three Argentinian lakes in the Pampa region of Argentina and the MAG of the Romanian lake Fără Fund, we describe the species Salinibacter pampae sp. nov. and Salinibacter abyssi sp. nov. respectively (showing ANI values 90.94% and 91.48% with Sal. ruber M31T, respectively). Sal. grassmerensis sp. nov. name was formed according to the rules of the International Code for Nomenclature of Prokaryotes (ICNP), and Sal. pepae, Sal. pampae sp. nov. and Sal. abyssi sp. nov. are proposed following the rules of the newly published Code of Nomenclature of Prokaryotes Described from Sequence Data (SeqCode). This work constitutes an example on how classification under ICNP and SeqCode can coexist, and how the official naming a cultivated organism for which the deposit in public repositories is difficult finds an intermediate solution.

Current -omics methods allow the collection of a large amount of information that helps in describing the microbial diversity in nature. Here, and as a result of a culturomic approach that rendered the collection of thousands of isolates from 5 different hypersaline sites (in Spain, USA and New Zealand), we obtained 21 strains that represent two new Salinibacter species. For these species we propose the names Salinibacter pepae sp. nov. and Salinibacter grassmerensis sp. nov. (showing average nucleotide identity (ANI) values < 95.09% and 87.08% with Sal. ruber M31T, respectively). Metabolomics revealed species-specific discriminative profiles. Sal. ruber strains were distinguished by a higher percentage of polyunsaturated fatty acids and specific N-functionalized fatty acids; and Sal. altiplanensis was distinguished by an increased number of glycosylated molecules. Based on sequence characteristics and inferred phenotype of metagenome-assembled genomes (MAGs), we describe two new members of the genus Salinibacter. These species dominated in different sites and always coexisted with Sal. ruber and Sal. pepae. Based on the MAGs from three Argentinian lakes in the Pampa region of Argentina and the MAG of the Romanian lake Fără Fund, we describe the species Salinibacter pampae sp. nov. and Salinibacter abyssi sp. nov. respectively (showing ANI values 90.94% and 91.48% with Sal. ruber M31T, respectively). Sal. grassmerensis sp. nov. name was formed according to the rules of the International Code for Nomenclature of Prokaryotes (ICNP), and Sal. pepae, Sal. pampae sp. nov. and Sal. abyssi sp. nov. are proposed following the rules of the newly published Code of Nomenclature of Prokaryotes Described from Sequence Data (SeqCode). This work constitutes an example on how classification under ICNP and SeqCode can coexist, and how the official naming a cultivated organism for which the deposit in public repositories is difficult finds an intermediate solution.

Figure S1. Geographical distribution of the six locations studied here and their inter-location distances (given in the table). The distances given in each location refer to Mallorca. The hypersaline here are: Mallorca (Es Trenc and S’Avall and separated by 3.5 km) and Santa Pola in Spain, Fără Fund in Romania, Great Salt Lake (USA), Pampa (Laguna Colorada Chica and Laguna Colorada Grande, separated by 23 Km), and Lake Grassmere (New Zealand). Table S1. Statistics of Salinibacter MAGs recovered using different bioinformatic tools. MAGs selected for further analysis and taxonomic classification are marked in red. Text S1: In addition to the taxonomic study, here we assessed the different tools SPADES and MegaHIT assemblers, and MetaBAT binning tools selecting contigs with length > 2,000 pbs or > 5,000 pbs to retrieve the best quality MAG (Sup. Table S1). We observed that different tools and combinations rendered different qualities of the MAGs. The selection of contigs with length > 5,000 pbs binning rendered MAGs with a lower genome size, lower completeness and similar contamination. From the FF metagenome (Romania), the highest quality MAG was retrieved using the assembler SPADES and MetaBAT binning tool using a minimum contig length of 2,000 pbs. From CCH and CG metagenomes (Argentina), the highest quality MAGs were retrieved using the assembler MegaHIT and MetaBAT binning tool using a minimum contig length of 2,000 pbs (Sup. Table S1). Figure S2. Genomic clustering based on Average Amino-acid Identity (AAI) of genomes included in the study. Figure S3. Pangenome hierarchical clustering based on the presence (grey) or absence (black) of orthologous genes. Table S2. Pangenome statistics between genomes belonging to the same species. Table S3: CRISPR-Cas systems found in the Salinibacter pepae and Salinibacter grassmerensis genomes. Table S4. Cell morphologies of the new isolates. All cells have been cultivated onto MA agar. for 10 days at 12ºC. The morphology was ob

Metagenomic surveys have revealed that natural microbial communities are predominantly composed of sequence-discrete, species-like populations but the genetic and/or ecological processes that maintain such populations remain speculative, limiting our understanding of population speciation and adaptation to perturbations. To address this knowledge gap, we sequenced 112 Salinibacter ruber isolates and 12 companion metagenomes from four adjacent saltern ponds in Mallorca, Spain that were experimentally manipulated to dramatically alter salinity and light intensity, the two major drivers of this ecosystem. Our analyses showed that the pangenome of the local Sal. ruber population is open and similar in size (~15,000 genes) to that of randomly sampled Escherichia coli genomes. While most of the accessory (noncore) genes were isolate-specific and showed low in situ abundances based on the metagenomes compared to the core genes, indicating that they were functionally unimportant and/or transient, 3.5% of them became abundant when salinity (but not light) conditions changed and encoded for functions related to osmoregulation. Nonetheless, the ecological advantage of these genes, while significant, was apparently not strong enough to purge diversity within the population. Collectively, our results provide an explanation for how this immense intrapopulation gene diversity is maintained, which has implications for the prokaryotic species concept.

Con el objetivo de obtener nuevos principios activos para su uso en la industria biotecnológica, se generó una colección de ~3000 cultivos puros a partir de distintas muestras ambientales que se identificaron mediante el uso en tándem de las técnicas de MALDI-TOF y secuenciación del gen que codifica para el ARNr 16S. De esta colección se seleccionó un número representativo con el fin de abarcar la mayor diversidad taxonómica y fenotípica, y así poder evaluar con mayor precisión el potencial biotecnológico de los aislados. Entre éstos se destacó una cepa aislada de una muestra de agua subterránea con anomalía térmica (~4ºC superior a la temperatura media de 25ºC) y que fue identificada como un nuevo miembro del género Hydrotalea. El estudio genómico nos permitió caracterizar sus particularidades genéticas y su singularidad filogenética, confirmando que se trataba de una nueva especie del género. Además, para profundizar en su relevancia ecológica, realizamos el estudio metagenómico de diferentes aguas subterráneas, incluida la muestra de origen, demostrando que esta nueva especie forma parte de la comunidad microbiana de estos ambientes y en proporciones suficientemente altas como para ser detectada molecularmente. Por tanto, al contrario de lo que ocurre normalmente, este aislado no forma parte de la biosfera rara en esos ambientes y probablemente tiene un papel ecológico relevante en el mismo.

From a collection of > 140 strains isolated from groundwater with thermal anomalies for the purpose of obtaining good candidates with applications in the cosmetic industry, two strains were selected because of their taxonomic novelty. Among the isolates, strains TMF_100T and TFM_099 stood out for their potential biotechnological relevance, and a comparative analysis of 16S rRNA gene sequences indicated that these strains represented a new species of the genus Hydrotalea. In addition, from the public genomic databases, metagenome-assembled genomes (MAGs) and single-cell amplified genomes (SAGs) could be retrieved that affiliated with this genus. These MAGs and SAGs had been obtained from different environmental samples, such as acid mine drainage or marine sediments. In addition to the description of the new species, the ecological relevance of the members of this genus was demonstrated by means of denitrification, CRISPR-Cas system diversity and heavy metal resistance, as well as their wide geographical distribution and environmental versatility. Supported by the taxonomic study, together with physiological and morphological differences and ecological features, we concluded that strain TMF_100T represented a novel species within the genus Hydrotalea, for which we propose the name Hydrotalea lipotrueae sp. nov.

The new release of the All-Species Living Tree Project (LTP) represents an important step forward in the reconstruction of 16S rRNA gene phylogenies, since we not only provide an updated set of type strain sequences until December 2020, but also a series of improvements that increase the quality of the database. An improved universal alignment has been introduced that is implemented in the ARB format. In addition, all low-quality sequences present in the previous releases have been substituted by new entries with higher quality, many of them as a result of whole genome sequencing. Altogether, the improvements in the dataset and 16S rRNA sequence alignment allowed us to reconstruct robust phylogenies. The trees made available through this current LTP release feature the best topologies currently achievable. The given nomenclature and taxonomic hierarchy reflect all the changes available up to December 2020. The aim is to regularly update the validly published nomenclatural classification changes and new taxa proposals. The new release can be found at the following URL: https://imedea.uib-csic.es/mmg/ltp/.

In the course of a bioprospective study of marine prokaryotes for cosmetic purposes, four strains, MD_567T, MD_652T, MD_674 and PS_109T, were isolated that 16S rRNA gene affiliation indicated could represent three new species within the family Alteromonadaceae. A thorough phylogenetic, genomic and phenotypic taxonomic study confirmed that the isolates could be classified as three new taxa for which we propose the names Alteromonas antoniana sp. nov., Alteromonas lipotrueae sp. nov. and Alteromonas lipotrueiana sp. nov. In addition, the consistent monophyletic nature of the members of the genera Alteromonas and Salinimonas showed that both taxa should be unified, and therefore we also propose the reclassification of the genus Salinimonas within Alteromonas, as well as new combinations for the species of the former. As the specific epithets profundi and sediminis are already used for Alteromonas species, we created the nomina nova “Alteromonas alteriprofundi” nom. nov. and Alteromonas alterisediminis nom. nov. to accommodate the new names for “Salinimonas profundi” and Salinimonas sediminis. Whole genome comparisons also allowed us to detect the unexpected codification of aromatic hydrocarbon biodegradative compounds, such as benzoate and catechol, whose activity was then demonstrated phenotypically. Finally, the high genomic identity between the type strains of Alteromonas stellipolaris and Alteromonas addita indicated that the latter is a junior heterotypic synonym of Alteromonas stellipolaris.

The increase in seawater temperature associated with global warming is a significant threat to coral health and is linked to increasing mass mortality events and Vibrio-related coral diseases. In the Mediterranean Sea, the endemic Cladocora caespitosa and the invasive species Oculina patagonica are the main scleractinian corals affected by mass mortalities. In this study, culturable Vibrio spp. assemblages associated with healthy and unhealthy colonies of these two shallow coral species were characterized to assess the presence of Vibrio pathogens in tissue necrosis. Vibrio communities associated with O. patagonica and C. caespitosa showed geographical differences, although these became more homogeneous in unhealthy specimens of both species. Furthermore, the number of recovered Vibrio specimens was more than five times higher in unhealthy than in healthy corals. Within these culturable vibrios, the known pathogens Vibrio mediterranei and Vibrio coralliilyticus were present in unhealthy colonies of both coral species in the two localities, suggesting that they could play a role in the health status of C. caespitosa and thus act as generalist pathogens in Mediterranean corals. Nonetheless, a clonal type of V. coralliilyticus detected in C. caespitosa was not associated with disease signs, suggesting that this species could encompass assemblages with different levels of virulence.

In the late summer of 2015, extensive mortality of scleratinian corals, gorgonians, and sponges was observed in the Marine Protected Area of Tabarca (southeast Spain). Quantitative data indicated that at 25 m depth the sea fan Eunicella singularis was the most affected species (50% of colonies affected by partial mortality); while in shallow waters more than 40% of the endemic scleractinian coral Cladocora caespitosa population showed tissue lesions that affected more than 10% of their surfaces. Other affected species were the scleractinian corals Oculina patagonica and Phyllangia mouchezii, the sea fan Leptogorgia sarmentosa and the sponge Sarcotragus fasciculatus. This mortality event coincided with an abnormal rise in seawater temperature in this region. Microbiological analysis showed a higher abundance of culturable Vibrio species in invertebrates exhibiting tissue lesions, which indicated that these opportunistic pathogens could be a key factor in the process.