Halophiles and Their Biomolecules: Recent Advances and Future Applications in Biomedicine

The organisms thriving under extreme conditions better than any other organism living on Earth, fascinate by their hostile growing parameters, physiological features, and their production of valuable bioactive metabolites. This is the case of microorganisms (bacteria, archaea, and fungi) that grow optimally at high salinities and are able to produce biomolecules of pharmaceutical interest for therapeutic applications. As along as the microbiota is being approached by massive sequencing, novel insights are revealing the environmental conditions on which the compounds are produced in the microbial community without more stress than sharing the same substratum with their peers, the salt. In this review are reported the molecules described and produced by halophilic microorganisms with a spectrum of action in vitro: antimicrobial and anticancer. The action mechanisms of these molecules, the urgent need to introduce alternative lead compounds and the current aspects on the exploitation and its limitations are discussed.España, MINECO CGL2017-83385-

Funcionalidad familiar en pacientes con diagnóstico de hipertensión arterial esencial controlada y no controlada de consulta externa y hospitalización del servicio de medicina interna y consulta externa de nefrología y cardiología del Hospital General Enrique Garcés

La hipertensión arterial (HTA) es una enfermedad crónica, poligénica y multifactorial, que se define como no controlada sí las cifras tensionales son ≥ 140/90 mmHg en todos los pacientes entre 18 y 60 años y sí la presión arterial sistólica es ≥150 mmHg en pacientes >60 años. Debido a que existen pacientes hipertensos que no cumplen los objetivos de presión arterial y por lo tanto tienen mayor riesgo de complicaciones cardiovasculares, cerebrovasculares, renales, arteriales y retinianas y que mediante investigaciones previas se ha determinado que cuando una persona padece algún tipo de enfermedad crónica, la evolución y respuesta al tratamiento depende del funcionamiento familiar, nos hemos visto en la necesidad de investigar dicha asociación. Objetivo: Establecer la relación entre el tipo de percepción de la funcionalidad familiar y el control de la HTA crónica en los pacientes de Consulta Externa y Hospitalización del Servicio de Medicina Interna y Consulta Externa de Nefrología y Cardiología del hospital General Enrique Garcés. Metodología: Se realizó un estudio analítico transversal de casos clínicos, observacional y prospectivo, usando un cuestionario auto aplicable (FF-SIL) validado en Cuba; las variables a evaluar fueron: funcionalidad familiar, edad, sexo, raza, escolaridad, estado civil, vivienda, tiempo de evolución de la enfermedad, grado de HTA, control de su HTA, conocimiento de su HTA y refractariedad a su manejo. Los datos y variables se procesaron mediante el programa estadístico SPSS 20 con una muestra de 240 permitiéndonos obtener un error máximo estimado de 5 %,con un nivel de confianza del 90%, y una p de 0,05. Resultados: En los pacientes evaluados se observó un predominio del sexo femenino (65.4%), y el mayor número de casos se encontraron en edades mayores de 60 años (56%). El tipo de funcionalidad familiar más frecuente fue el moderadamente funcional en un 44,2%. Además se evidenció que de todos los pacientes con presión arterial controlada el 25,4% y 33,8% correspondían a familias funcionales y moderadamente funcionales respectivamente y que sólo el 7,5% y 1,2% de los pacientes con familias disfuncionales y severamente disfuncionales respectivamente controlan su presión arterial con el tratamiento administrado. Se realizó la prueba de Chi-cuadrado de Pearson con un valor de 14,587 y una p de 0,002 evidenciándose su significancia estadística

Genotypic and Lipid Analyses of Strains From the Archaeal Genus Halorubrum Reveal Insights Into Their Taxonomy, Divergence, and Population Structure

To gain a better understanding of how divergence occurs, and how taxonomy can benefit from studying natural populations, we isolated and examined 25 closely related Halorubrum strains obtained from different hypersaline communities and compared them to validly named species and other reference strains using five taxonomic study approaches: phylogenetic analysis using the 16S rRNA gene and multilocus sequencing analysis (MLSA), polar lipid profiles (PLP), average nucleotide identity (ANI) and DNA-DNA hybridization (DDH). 16S rRNA gene sequence could not differentiate the newly isolated strains from described species, while MLSA grouped strains into three major clusters. Two of those MLSA clusters distinguished candidates for new species. The third cluster with concatenated sequence identity equal to or greater than 97.5% was comprised of strains from Aran-Bidgol Lake (Iran) and solar salterns in Namibia and Spain, and two previously described species isolated from Mexico and Algeria. PLP and DDH analyses showed that Aran-Bidgol strains formed uniform populations, and that strains isolated from other geographic locations were heterogeneous and divergent, indicating that they may constitute different species. Therefore, applying only sequencing approaches and similarity cutoffs for circumscribing species may be too conservative, lumping concealed diversity into a single taxon. Further, our data support the interpretation that local populations experience unique evolutionary homogenization pressures, and once relieved of insular constraints (e.g., through migration) are free to diverge.España, MINECO Projects CGL2013-46941-P and CGL2017-83385-

Biosynthetic gene profiling and genomic potential of the novel photosynthetic marine bacterium Roseibaca domitiana

Shifting the bioprospecting targets toward underexplored bacterial groups combined with genome mining studies contributes to avoiding the rediscovery of known compounds by revealing novel, promising biosynthetic gene clusters (BGCs). With the aim of determining the biosynthetic potential of a novel marine bacterium, strain V10T, isolated from the Domitian littoral in Italy, a comparative phylogenomic mining study was performed across related photosynthetic bacterial groups from an evolutionary perspective. Studies on polyphasic and taxogenomics showed that this bacterium constitutes a new species, designated Roseibaca domitiana sp. nov. To date, this genus has only one other validly described species, which was isolated from a hypersaline Antarctic lake. The genomic evolutionary study linked to BGC diversity revealed that there is a close relationship between the phylogenetic distance of the members of the photosynthetic genera Roseibaca, Roseinatronobacter, and Rhodobaca and their BGC profiles, whose conservation pattern allows discriminating between these genera. On the contrary, the rest of the species related to Roseibaca domitiana exhibited an individual species pattern unrelated to genome size or source of isolation. This study showed that photosynthetic strains possess a streamlined content of BGCs, of which 94.34% of the clusters with biotechnological interest (NRPS, PKS, RRE, and RiPP) are completely new. Among these stand out T1PKS, exclusive of R. domitiana V10T, and RRE, highly conserved only in R. domitiana V10T and R. ekhonensis, both categories of BGCs involved in the synthesis of plant growth-promoting compounds and antitumoral compounds, respectively. In all cases, with very low homology with already patented molecules. Our findings reveal the high biosynthetic potential of infrequently cultured bacterial groups, suggesting the need to redirect attention to microbial minorities as a novel and vast source of bioactive compounds still to be exploited

Horizontal gene transfer, dispersal and haloarchaeal speciation

The Halobacteria are a well-studied archaeal class and numerous investigations are showing how their diversity is distributed amongst genomes and geographic locations. Evidence indicates that recombination between species continuously facilitates the arrival of new genes, and within species, it is frequent enough to spread acquired genes amongst all individuals in the population. To create permanent independent diversity and generate new species, barriers to recombination are probably required. The data support an interpretation that rates of evolution (e.g., horizontal gene transfer and mutation) are faster at creating geographically localized variation than dispersal and invasion are at homogenizing genetic differences between locations. Therefore, we suggest that recurrent episodes of dispersal followed by variable periods of endemism break the homogenizing forces of intrapopulation recombination and that this process might be the principal stimulus leading to divergence and speciation in Halobacteria

Identification of a Sorbicillinoid-Producing Aspergillus Strain with Antimicrobial Activity Against Staphylococcus aureus: a New Polyextremophilic Marine Fungus from Barents Sea

The exploration of poorly studied areas of Earth can highly increase the possibility to discover novel bioactive compounds. In this study, the cultivable fraction of fungi and bacteria from Barents Sea sediments has been studied to mine new bioactive molecules with antibacterial activity against a panel of human pathogens. We isolated diverse strains of psychrophilic and halophilic bacteria and fungi from a collection of nine samples from sea sediment. Following a full bioassay-guided approach, we isolated a new promising polyextremophilic marine fungus strain 8Na, identified as Aspergillusprotuberus MUT 3638, possessing the potential to produce antimicrobial agents. This fungus, isolated from cold seawater, was able to grow in a wide range of salinity, pH and temperatures. The growth conditions were optimised and scaled to fermentation, and its produced extract was subjected to chemical analysis. The active component was identified as bisvertinolone, a member of sorbicillonoid family that was found to display significant activity against Staphylococcus aureus with a minimum inhibitory concentration (MIC) of 30 μg/mL. © 2018, Springer Science+Business Media, LLC, part of Springer Nature

Genomic study and lipidomic bioassay of Leeuwenhoekiella parthenopeia: A novel rare biosphere marine bacterium that inhibits tumor cell viability

The fraction of low-abundance microbiota in the marine environment is a promising target for discovering new bioactive molecules with pharmaceutical applications. Phenomena in the ocean such as diel vertical migration (DVM) and seasonal dynamic events influence the pattern of diversity of marine bacteria, conditioning the probability of isolation of uncultured bacteria. In this study, we report a new marine bacterium belonging to the rare biosphere, Leeuwenhoekiella parthenopeia sp. nov. Mr9T, which was isolated employing seasonal and diel sampling approaches. Its complete characterization, ecology, biosynthetic gene profiling of the whole genus Leeuwenhoekiella, and bioactivity of its extract on human cells are reported. The phylogenomic and microbial diversity studies demonstrated that this bacterium is a new and rare species, barely representing 0.0029% of the bacterial community in Mediterranean Sea metagenomes. The biosynthetic profiling of species of the genus Leeuwenhoekiella showed nine functionally related gene cluster families (GCF), none were associated with pathways responsible to produce known compounds or registered patents, therefore revealing its potential to synthesize novel bioactive compounds. In vitro screenings of L. parthenopeia Mr9T showed that the total lipid content (lipidome) of the cell membrane reduces the prostatic and brain tumor cell viability with a lower effect on normal cells. The lipidome consisted of sulfobacin A, WB 3559A, WB 3559B, docosenamide, topostin B-567, and unknown compounds. Therefore, the bioactivity could be attributed to any of these individual compounds or due to their synergistic effect. Beyond the rarity and biosynthetic potential of this bacterium, the importance and novelty of this study is the employment of sampling strategies based on ecological factors to reach the hidden microbiota, as well as the use of bacterial membrane constituents as potential novel therapeutics. Our findings open new perspectives on cultivation and the relationship between bacterial biological membrane components and their bioactivity in eukaryotic cells, encouraging similar studies in other members of the rare biosphere

Genomic-based phylogenetic and metabolic analyses of the genus Natronomonas, and description of Natronomonas aquatica sp. nov.

The genus Natronomonas is classified on the family Haloarculaceae, within the class Halobacteria and currently includes six species isolated from salterns, saline or soda lakes, and salt mines. All are extremely halophilic (optimal growth at 20–25% [w/v] NaCl) and neutrophilic, except Natronomonas pharaonis, the type species of the genus, that is haloalkaliphilic (showing optimal growth at pH 9.0) and possesses distinct phenotypic features, such as a different polar lipid profile than the rest of species of the genus. We have carried out a genome-based study in order to determine the phylogenetic structure of the genus Natronomonas and elucidate its current taxonomic status. Overall genomic relatedness indexes, i.e., OrthoANI (Average Nucleotide Identity), dDDH (digital DNA–DNA hybridization), and AAI (Average Amino acid Identity), were determined with respect to the species of Natronomonas and other representative taxa of the class Halobacteria. Our data show that the six species of Natronomonas constitute a coherent cluster at the genus level. Besides, we have characterized a new haloarchaeon, strain F2-12T, isolated from the brine of a pond of a saltern in Isla Cristina, Huelva, Spain, and we determined that it constitutes a new species of Natronomonas, for which we propose the name Natronomonas aquatica sp. nov. Besides, the metabolic analysis revealed a heterotrophic lifestyle and a versatile nitrogen metabolism for members of this genus. Finally, metagenomic fragment recruitments from a subset of hypersaline habitats, indicated that the species of Natronomonas are widely distributed in saline lakes and salterns as well as on saline soils. Species of this haloarchaeal genus can be considered as ubiquitous in intermediate to high salinity habitats

Genetic diversity of HLA system in four populations from Baja California, Mexico: Mexicali, La Paz, Tijuana and rural Baja California

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 250 Mexicans from the states of Baja California Norte and Baja California Sur living in Mexicali (N = 100), La Paz (N = 75), Tijuana (N = 25) and rural communities (N = 50) to obtain information regarding allelic and haplotypic frequencies. The most frequent haplotypes for the Baja California region include nine Native American and five European haplotypes. Admixture estimates revealed that the main genetic components are European (50.45 ± 1.84% by ML; 42.03% of European haplotypes) and Native American (43.72 ± 2.36% by ML; 40.24% of Native American haplotypes), while the African genetic component was less apparent (5.83 ± 0.98% by ML; 9.36% of African haplotypes)