Diversidad microbiana de los sedimentos anaerobios de río Tinto

Tesis doctoral inédita, leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de lectura: 13-07-201

Sulfur reduction in acid rock drainage environments

Microbiological suitability of acidophilic sulfur reduction for metal recovery was explored by enriching sulfur reducers from acidic sediments at low pH (from 2 to 5) with hydrogen, glycerol, methanol and acetate as electron donors at 30 °C. The highest levels of sulfide in the enrichments were detected at pH 3 with hydrogen and pH 4 with acetate. Cloning and sequencing of the 16S rRNA gene showed dominance of the deltaproteobacterial sulfur-reducing genus Desulfurella in all the enrichments and subsequently an acidophilic strain (TR1) was isolated. Strain TR1 grew at a broad range of pH (37) and temperature (2050 °C) and showed good metal tolerance (Pb2+, Zn2+, Cu2+, Ni2+), especially for Ni2+ and Pb2+, with maximal tolerated concentrations of 0.09 and 0.03 mM, respectively. Different sources of sulfur were tested in the enrichments, from which biosulfur showed fastest growth (doubling time of 1.9 days), followed by colloidal, chemical and sublimated sulfur (doubling times of 2.2, 2.5, and 3.6 days, respectively). Strain TR1?s physiological traits make it a good candidate to cope with low pH and high metal concentration in biotechnological processes for treatment of metal-laden acidic streams at low and moderately high temperature

Unemployment's effects in relationships, in the family atmosphere and in the mental health

El objetivo del presente estudio es analizar los efectos del desempleo en las relaciones de pareja, en el ambiente familiar y en la salud mental. Para ello se han tenido en cuenta variables como la edad, el sexo, el número de hijos y el tiempo de relación. Para llevar a cabo la presente investigación se ha llevado a cabo con una muestra de 70 personas (35 parejas heterosexuales). Este grupo de sujetos se reparte en cuatro condiciones: ambos empleados, mujer desempleada, hombre desempleado y ambos desempleados. Perteneciendo a cada grupo 12 parejas, 8 parejas, 6 parejas y 9 parejas, respectivamente. Las conclusiones de este estudio indican que la situación laboral no influye ni en las relaciones de pareja ni en el ambiente familiar. Sin embargo, se encuentran efectos significativos en la salud mental.The object of the present study is to analyze the unemployment’s effects in the relationships, in the family atmosphere and in the mental health. For this goal we have considered the next variables: age, gender, number of children and relationship time. We have done the investigation with a sample of 72 people (36 heterosexual couples). This sample is distributed in four conditions: Both unemployed, woman unemployed, man unemployed and both unemployed. Each group had 12 couples, 8 couples, 6 couples and 9 couples, respectively. The findings of this study indicate that the employment situation does not affect the relationships or the family atmosphere. However, there are significant effects on mental health.Universidad de Granada. Departamento de Psicología Social. Proyecto de Innovación Docente ReiDoCre

Elevated Lead, Nickel, and Bismuth Levels in the Peritoneal Fluid of a Peritoneal Endometriosis Patient without Toxic Habits or Occupational Exposure following a Vegetarian Diet

Potentially toxic elements (PTEs), found as environmental contaminants, have been related to endometriosis disease. In this context, the peritoneal fluid (PF) matrix has been poorly studied despite its importance. PF is the environment in which endometriotic lesions reside and communicate with surrounding tissues including tissues and nerve cells. In this work, our investigation group reports the special case of a peritoneal endometriosis patient presenting elevated lead, nickel, and bismuth levels in PF. This patient reported following a vegetarian diet and no toxic habits or occupational exposure. In conclusion, the elevated levels of PTEs found may result from a vegetarian diet or an unidentified environmental exposure source. This report provides new insights regarding the possible etiology of endometriosis disease and potential biomarkers for its diagnosis in early stages, although additional research is needed.This study was funded by the Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunitat Valenciana (UGP-19-042 and UGP-20-039). A.L.-B. is supported by the European Social Fund and the Generalitat Valenciana under a Ph.D. contract (ACIF–2021/243)

Prospects for harnessing biocide resistance for bioremediation and detoxification

Prokaryotes in natural environments respond rapidly to high concentrations of chemicals and physical stresses. Exposure to anthropogenic toxic substancessuch as oil, chlorinated solvents, or antibioticsfavors the evolution of resistant phenotypes, some of which can use contaminants as an exclusive carbon source or as electron donors and acceptors. Microorganisms similarly adapt to extreme pH, metal, or osmotic stress. The metabolic plasticity of prokaryotes can thus be harnessed for bioremediation and can be exploited in a variety of ways, ranging from stimulated natural attenuation to bioaugmentation and from wastewater treatment to habitat restoration.We thank H. Stroo (Stroo Consulting) and C. Aziz (Ramboll) for providing photographs of bioaugmentation with OHRB, and H. Patzelt (Mazoon Environmental and Technological Services) for providing photographs of bioaugmentation with halophilic microorganisms. Funding: S.A., I.S.-A., and A.J.M.S. are supported by the Netherlands Ministry of Education, Culture and Science (project 024.002.002) and advanced ERC grant (project 323009). H.S. and S.A. were supported by a grant of BE-Basic-FES funds from the Dutch Ministry of Economic Affairs. H.S., J.R.v.d.M., and H.J.H. were supported by the European Commission (BACSIN, contract 211684; P4SB, contract 633962).info:eu-repo/semantics/publishedVersio

A case in support of implementing innovative bio-processes in the metal mining industry

The metal mining industry faces many large challenges in future years, among which is the increasing need to process low-grade ores as accessible higher grade ores become depleted. This is against a backdrop of increasing global demands for base and precious metals, and rare earth elements. Typically about 99% of solid material hauled to, and ground at, the land surface currently ends up as waste (rock dumps and mineral tailings). Exposure of these to air and water frequently leads to the formation of acidic, metal-contaminated run-off waters, referred to as acid mine drainage, which constitutes a severe threat to the environment. Formation of acid drainage is a natural phenomenon involving various species of lithotrophic (literally rock-eating) bacteria and archaea, which oxidise reduced forms of iron and/or sulfur. However, other microorganisms that reduce inorganic sulfur compounds can essentially reverse this process. These microorganisms can be applied on industrial scale to precipitate metals from industrial mineral leachates and acid mine drainage streams, resulting in a net improvement in metal recovery, while minimising the amounts of leachable metals to the tailings storage dams. Here, we advocate that more extensive exploitation of microorganisms in metal mining operations could be an important way to green up the industry, reducing environmental risks and improving the efficiency and the economy of metal recovery.Research of AJMS and ISA was supported by European Research Council (ERC) grant [project 323009] and Gravitation grant [project 024.002.002] from the Netherlands Ministry of Education, Culture and Science

Pontiella desulfatans gen. nov., sp. nov., and Pontiella sulfatireligans sp. nov., two marine anaerobes of the Pontiellaceae fam. nov. producing sulfated glycosaminoglycan-like exopolymers

Recently, we isolated two marine strains, F1T and F21T, which together with Kiritimatiella glycovorans L21-Fru-ABT are the only pure cultures of the class Kiritimatiellae within the phylum Verrucomicrobiota. Here, we present an in-depth genome-guided characterization of both isolates with emphasis on their exopolysaccharide synthesis. The strains only grew fermentatively on simple carbohydrates and sulfated polysaccharides. Strains F1T, F21T and K. glycovorans reduced elemental sulfur, ferric citrate and anthraquinone-2,6-disulfonate during anaerobic growth on sugars. Both strains produced exopolysaccharides during stationary phase, probably with intracellularly stored glycogen as energy and carbon source. Exopolysaccharides included N-sulfated polysaccharides probably containing hexosamines and thus resembling glycosaminoglycans. This implies that the isolates can both degrade and produce sulfated polysaccharides. Both strains encoded an unprecedently high number of glycoside hydrolase genes (422 and 388, respectively), including prevalent alpha-L-fucosidase genes, which may be necessary for degrading complex sulfated polysaccharides such as fucoidan. Strain F21T encoded three putative glycosaminoglycan sulfotransferases and a putative sulfate glycosaminoglycan biosynthesis gene cluster. Based on phylogenetic and chemotaxonomic analyses, we propose the taxa Pontiella desulfatans F1T gen. nov., sp. nov. and Pontiella sulfatireligans F21T sp. nov. as representatives of the Pontiellaceae fam. nov. within the class Kiritimatiellae.ERC -European Research Council(024.002.002)info:eu-repo/semantics/publishedVersio

Multi-production of high added market value metabolites from diluted methane emissions via methanotrophic extremophiles

Producción CientíficaThis study constitutes the first-proof-of-concept of a methane biorefinery based on the multi-production of high profit margin substances (ectoine, hydroxyectoine, polyhydroxyalkanoates (PHAs) and exopolysaccharides (EPS)) using methane as the sole carbon and energy source. Two bubble column bioreactors were operated under different magnesium concentrations (0.2, 0.02 and 0.002 g L−1) to validate and optimize this innovative strategy for valorization of CH4 emissions. High Mg2+ concentrations promoted the accumulation of ectoine (79.7–94.2 mg g biomass−1), together with high hydroxyectoine yields (up to 13 mg g biomass−1) and EPS concentrations (up to 2.6 g L culture broth−1). Unfortunately, PHA synthesis was almost negligible (14.3 mg L−1) and only found at the lowest Mg2+ concentration tested. Halomonas, Marinobacter, Methylophaga and Methylomicrobium, previously described as ectoine producers, were dominant in both bioreactors, Methylomicrobium being the only described methanotroph. This study encourages further research on CH4 biorefineries capable of creating value out of GHG mitigation.Ministerio de Economía, Industria y Competitividad (Project CTM2015-70442-RNOVEDAR)Junta de Castilla y León (programa de apoyo a proyectos de investigación – Ref. E-47-2014-0140696UIC71

Novel haloalkaliphilic methanotrophic bacteria: An attempt for enhancing methane bio-refinery

Producción CientíficaMethane bioconversion into products with a high market value, such as ectoine or hydroxyectoine, can be optimized via isolation of more efficient novel methanotrophic bacteria. The research here presented focused on the enrichment of methanotrophic consortia able to co-produce different ectoines during CH4 metabolism. Four different enrichments (Cow3, Slu3, Cow6 and Slu6) were carried out in basal media supplemented with 3 and 6% NaCl, and using methane as the sole carbon and energy source. The highest ectoine accumulation (∼20 mg ectoine g biomass−1) was recorded in the two consortia enriched at 6% NaCl (Cow6 and Slu6). Moreover, hydroxyectoine was detected for the first time using methane as a feedstock in Cow6 and Slu6 (∼5 mg g biomass−1). The majority of the haloalkaliphilic bacteria identified by 16S rRNA community profiling in both consortia have not been previously described as methanotrophs. From these enrichments, two novel strains (representing novel species) capable of using methane as the sole carbon and energy source were isolated: Alishewanella sp. strain RM1 and Halomonas sp. strain PGE1. Halomonas sp. strain PGE1 showed higher ectoine yields (70–92 mg ectoine g biomass−1) than those previously described for other methanotrophs under continuous cultivation mode (∼37–70 mg ectoine g biomass−1). The results here obtained highlight the potential of isolating novel methanotrophs in order to boost the competitiveness of industrial CH4-based ectoine production.Ministerio de Economía, Industria y Competitividad (Project CTM2015-70442-R project and Red NOVEDAR)Junta de Castilla y León (programa de apoyo a proyectos de investigación – Ref. UIC71)European Union through the FEDER Funding Program (PhD Grant contract Nº E-47-2014-0140696

Co-culture of a novel fermentative bacterium, Lucifera butyrica gen. nov. sp. nov., with the sulfur reducer Desulfurella amilsii for enhanced sulfidogenesis

Biosulfidogenesis can be used to remediate low pH and high metal content waters such as acid mine drainage and recover the present metals. The selection of a cheap electron donor for the process is important for the economic viability. In this work we isolated a novel versatile acidotolerant fermentative bacterium (strain ALET) that is able to use a great variety of substrates including glycerol. Strain ALET is an obligate anaerobe, and cells are motile, rod-shaped, spore-forming, and stain Gram-positive. Growth occurred in a pH range from 3.5 to 7 (optimum 5.5), and temperature range from 25 to 40°C (optimum 37°C). It grows by fermentation of sugars, organic acids and glycerol. It has the ability to use thiosulfate, iron and DMSO as electron acceptors. Its genome is 4.7 Mb with 5122 protein-coding sequences, and a G+C content of 46.9 mol%. Based on 16S rRNA gene sequence analysis, the closest cultured species is Propionispora hippei (91.4% 16S rRNA gene identity) from the Sporomusaceae family (Selenomonadales order, Negativicutes class, Firmicutes phylum). Based on the distinctive physiological and phylogenetic characteristics of strain ALET, a new genus and species Lucifera butyrica gen. nov., sp. nov., is proposed. The type strain is ALET (=JCM 19373T=DSM 27520T). Strain ALET is an incomplete oxidizer and acetate, among other products, accumulates during glycerol conversion. Strain ALET was used to extend the substrate range for sulfur reduction by constructing cocultures with the acetate oxidizer and sulfur reducer Desulfurella amilsii. The coculture was tested with glycerol as substrate in batch and chemostat experiments. Acetate formed by fermentation of glycerol by strain ALET resulted in sulfur reduction by D. amilsii. The coculture strategy offers good perspectives to use a wide range of cost-efficient substrates, including glycerol, to produce sulfide by specialized sulfur reducers. The recovery of heavy metals from metalliferous streams may become economically feasible by this approach.The doctoral study program was supported by CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico), organization of the Brazilian Government. Research of DS, IS-A, and AS is financed by an ERC grant (Project 323009) and the Gravitation grant (SIAM 024.002.002) of the Netherlands Ministry of Education, Culture and Science and the Netherlands Science Foundation.info:eu-repo/semantics/publishedVersio