1,380 research outputs found
The evolution of glutathione metabolism in phototrophic microorganisms
The low molecular weight thiol composition of a variety of phototropic microorganisms is examined in order to ascertain how evolution of glutathione (GSH) production is related to the evolution of oxygenic photosynthesis. Cells were extracted in the presence of monobromobimane (mBBr) to convert thiols (RSH) to fluorescent derivatives (RSmB) which were analyzed by high performance liquid chromatography (HPLC). Significant levels of GSH were not found in green sulfur bacteria. Substantial levels were present in purple bacteria, cyanobacteria, and eukaryotic algae. Other thiols measured included cysteine, gamma-glutamylcysteine, thiosulfate, coenzyme A, and sulfide. Many of the organisms also exhibited a marked ability to reduce mBBr to syn-(methyl,methyl)bimane, an ability which was quenched by treatment with 2-pyridyl disulfide or 5,5 prime-bisdithio - (2-nitrobenzoic acid) prior to reaction with mBBr. These observations indicate the presence of a reducing system capable of electron transfer to mBBr and reduction of reactive disulfides. The distribution of GSH in phototropic eubacteria indicates that GSH synthesis evolved at or around the time that oxygenic photosynthesis evolved
Spatial distribution of bacteria associated with the marine sponge Tethya californiana
Microbial diversity and spatial distribution of the diversity within tissue of the marine sponge Tethya californiana was analyzed based on 16S rRNA gene sequences. One candidate division and nine bacterial phyla were detected, including members of all five subdivisions of Proteobacteria. Moreover, chloroplast-derived Stramenopiles- and Rhodophyta-affiliated 16S rRNA gene sequences were found and Stramenopiles represented the most abundant clones (30%) in the clone library. On the phylum-level, the microbial fingerprint of T. californiana showed a similar pattern as its Mediterranean relative T. aurantium. An interesting difference was that Cyanobacteria that were abundantly present in T. aurantium were not found in T. californiana, but that the latter sponges harbored phototrophic Stramenopiles instead. Surprisingly, the phototrophic microorganisms were evenly distributed over the inner and outer parts of the sponge tissue, which implies that they also reside in regions without direct light exposure. The other phyla were also present in both the outer cortex and the mesohyl of the sponges. These results were confirmed by analysis on the operational taxonomic unit level. This leads to the conclusion that from a qualitative point of view, spatial distribution of microorganisms in T. californiana tissue is quite homogeneous. Thirty-two percent of the operational taxonomic units shared less than 95% similarity with any other known sequence. This indicates that marine sponges are a rich source of previously undetected microbial lif
Weathering of a Roman Mosaic-A Biological and Quantitative Study on In Vitro Colonization of Calcareous Tesserae by Phototrophic Microorganisms
The potential impact of cyanobacteria and microalgae on the weathering of calcareous tesserae from a Roman mosaic of the II Century CE has been followed through in vitro experiments. Laboratory tests were carried out by inoculating mosaic tiles with single strains of Cyanobacteria or Chlorophyta to evaluate the roles of pioneer phototrophic microrganism on the resulting architecture of biofilms. The interaction between tesserae and strains was assessed at the whole substratum and micrometer scales, by image analysis and Confocal Laser Scanning (CLS) microscopy, respectively. The biofilm surface coverage on each tessera varied from 19% (Fischerella ambigua) to 97% (Microcoleus autumnalis). Cyanobacteria showed a better growth on calcareous tesserae, whereas the only green alga attaining a superficial coverage higher than 50% was Coelastrella rubescens. CLS microscopy evidenced two different types of spatial arrangement of the phototrophic organisms on the tesserae, that were defined as compact or porous, respectively. In the first one was measured a reduced number of empty spaces between cells or filaments, whereas in the second type, a reticulate texture allowed the presence of numerous empty volumes. The colonization processes observed are an intrinsic characteristic of each strain. We have proposed a colonization index IC as a sensible tool to describe, in a quantitative way, the pioneering attitude of each photosynthetic microorganism to colonize lithic substrates under laboratory conditions
Thiol biochemistry of prokaryotes
The present studies have shown that GSH metabolism arose in the purple bacteria and cyanobacteria where it functions to protect against oxygen toxicity. Evidence was obtained indicating that GSH metabolism was incorporated into eucaryotes via the endosymbiosis giving rise to mitochrondria and chloroplasts. Aerobic bacteria lacking GSH utilize other thiols for apparently similar functions, the thiol being coenzyme A in Gram positive bacteria and chi-glutamylcysteine in the halobacteria. The thiol biochemistry of prokaryotes is thus seen to be much more highly diversified than that of eucaryotes and much remains to be learned about this subject
The deterioration of Circular Mausoleum, Roman Necropolis of Carmona, Spain
The Circular Mausoleum tomb in the Roman Necropolis of Carmona was carved on a calcarenite sequence in an ancient quarry located in the town of Carmona, Southern Spain. This rock-cut tomb, representative of Roman burial practices, currently suffers from serious deterioration. A detailed survey over several years permitted the identification of the main tomb's pathologies and damaging processes, which include loss of material (scaling, flaking, granular disintegration), surface modifications (efflorescences, crusts and deposits) and extensive biological colonization. The results obtained in this study indicated that anthropogenic changes were largely responsible and enhanced the main alteration mechanisms observed in the Circular Mausoleum. Based on the deterioration diagnosis, effective corrective actions were proposed. This study shows that any conservative intervention in the interior of the tomb should be preceded by accurate in situ measurements and laboratory analyses to ascribe the source of the deterioration damages and thus designing effective treatments.This research was funded by the Consejeria de Cultura, Junta de Andalucia, the Spanish Ministry of Science and Innovation project CGL2010-17183, and the program Torres Quevedo (PTQ 13-06296 and PTQ 12-05601)
An integrated approach for assessing the bioreceptivity of glazed tiles to phototrophic microorganisms
18 páginas.-- 7 figuras.-- 5 tablas.-- 63 referenciasA laboratory-based methodology was designed to assess the bioreceptivity of glazed tiles. The experimental set-up consisted of multiple steps: manufacturing of pristine and artificially aged glazed tiles, enrichment of phototrophic microorganisms, inoculation of phototrophs on glazed tiles, incubation under optimal conditions and quantification of biomass. In addition, tile intrinsic properties were assessed to determine which material properties contributed to tile bioreceptivity. Biofilm growth and biomass were appraised by digital image analysis, colorimetry and chlorophyll a analysis. SEM, micro-Raman and micro-particle induced X-ray emission analyses were carried out to investigate the biodeteriorating potential of phototrophic microorganisms on the glazed tiles. This practical and multidisciplinary approach showed that the accelerated colonization conditions allowed different types of tile bioreceptivity to be distinguished and to be related to precise characteristics of the material. Aged tiles showed higher bioreceptivity than pristine tiles due to their higher capillarity and permeability. Moreover, biophysical deterioration caused by chasmoendolithic growth was observed on colonized tile surfaces.This work was supported by the Portuguese Foundation for Science and Technology (FCT) [grant SFRH/BD/46038/2008; project UID/EAT/00729/2013]. A.Z. Miller acknowledges support from a Marie Curie Intra-European Fellowship of the European Commission’s 7th Framework Programme [PIEF-GA-2012-328689]. J.P. Veiga and H. Águas acknowledge funding by FEDER funds through the COMPETE 2020 Programme and National Funds through FCT [project UID/ CTM/50025/2013]. This work was supported by the European Commission’s 7th Framework Programme, through the Marie Curie International Research Staff Exchange Scheme [NANO_GUARD (PIRSES-GA-2010-269138)].Peer reviewe
Diversity of N2-fixing cyanobacteria from Andalusian paddy fields and analysis of their potential as bioinoculants
The marshes of the Guadalquivir River contain the largest area of rice cultivation in Spain, where more than 40,000 ha are used every year for rice production. These wetland areas provide a perfect place for rice cultivation, and represent a unique aquaticterrestrial habitat that hold more wintering waterfowl than any other European wetland.
Paddies require large amounts nitrogen and phosphorus for their growth, development and production. Though, flooded conditions used for rice cultivation drastically diminish efficiency inorganic nitrogen fertilizers, being only 30–40% used by the plant, and in some cases even less. Large amounts of nitrogen fertilizers are dissolved in the surface water and lost, causing environmental pollution and health problems due to losses through N2O and NO volatilization, denitrification, and leaching (Ishii et al., 2011)
Mineral waters of Serbia and development of phototrophic microbial communities near points of emergence and on wellheads
Phototropic microorganisms in thermal mats had not attracted enough attention in Serbia in the past. The research presented in this paper is the first to address biofilms at selected occurrences of mineral water in Serbia (Bogatic, Metkovic and Belotic in the Macva District as well as Radaljska Banja, Lukovska Banja and Vranjska Banja) (in Serbian, banja denotes a spa town). The study period is from 2014 to 2016. The temperatures of the studied occurrences are in the 30-93.9 degrees C range and the chemical composition corresponds to the HCO3- -Na++ K+ and SO42-, HCO3--Na++ K+ types of mineral water. One of the objectives was to examine the condition of wellheads (incrustation, biofouling and corrosion), focusing on the presence of phototrophic microorganisms whose metabolites may lead to changes in mineral water quality, yield and chemistry. Analysis by light and scanning electron microscopy provides insight into the diversity of phototrophic microorganisms that populate biofilms near the points of emergence and on wellhead. The research reveals the presence of representatives of three groups of phototrophic microorganisms: Cyanobacteria, Chlorophyta and Bacillariophyta. Cyanobacteria were the most numerous, dominated by the order Oscillatoriales with ten recorded genera, of which Leptolynbgya and Phormidium feature the largest numbers of species. The order Chroococcales are the second most numerous, with seven recorded genera, of which Gloeocapsa and Synechocystisare the most noteworthy. The largest numbers of representative taxa were noted at Radaljska Banja and Vranjska Banja, where mineral waters originate from lithostratigraphic units of igneous origin, followed by mineral water occurrences in karst aquifers (Bogatic and Belotic) and an intergranular aquifer (Metkovic). The smallest number of identified phototrophic microorganisms is noted at Lukovska Banja, where the origin is associated with a fractured aquifer formed in sedimentary and metamorphic rocks, with occasional diabase interbeds. Although many representative taxa are found on only one of the studied localities, such as Synechococcus bigranulatus and Pseudanabaena thermalis, those of the genera Leptolyngbya, Phormidium and Cosmarium laeve, as well as genera of the phylum Bacillariophyta, occur at several sampling sites. Principal component analysis (PCA) was used to show the relationship between documented cyanobacterial and algal taxa and environmental parameters
Sustainable Design of Wastewater Treatment Systems: Evaluations of Operational Flexibility and Phototrophs for Resource Recovery.
The overarching goal of this dissertation is to advance the sustainability of wastewater systems. Although concepts surrounding sustainable wastewater infrastructure have advanced in recent years, a defined methodology to develop designs and elucidate trade-offs across dimensions of sustainability (social, economic, environmental, functional), space (local, regional, global), and time (present, future) does not exist. In particular, social barriers have not been sufficiently addressed and there is a lack of integration in quantitative assessments of economic, environmental, and functional sustainability. This limitation not only impacts the industry’s ability to develop more sustainable designs and evaluate configuration alternatives, but it also inhibits the comparative evaluation of traditional with emerging technologies in wastewater management (e.g., the use of phototrophic microorganisms for energy recovery). In order to address social factors, we have developed a planning and design process for wastewater treatment systems that is centered on a process of continuous stakeholder participation and that is enhanced through communication tools and lessons learned from the social sciences literature. To provide stakeholders with the a broader set of information in the context of WWTP design, we have also integrated state of the art tools to assess the performance, cost, and life cycle environmental impacts of WWTP designs. Although these tools have been developed independent of one another in the literature, their integration creates opportunities to elucidate tensions and synergistic relationships among goals for sustainability. Ultimately, this methodology and the case study used for its demonstration offer insight into broader themes of WWTP sustainability, improve designs in multiple dimensions, and provide a framework to evaluate emerging technologies in wastewater management. Finally, we have developed a phototrophic process model to predict the performance of phototrophic microorganisms as an energy recovery technology. Through these efforts, this dissertation advances the sustainability of wastewater treatment systems by facilitating sustainable design and decision-making in the context of WWTP design and operation.Ph.D.Environmental EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/91603/1/jsguest_1.pd
Mineral waters of Serbia and development of phototrophic microbial communities near points of emergence and on wellheads
Phototropic microorganisms in thermal mats had not attracted enough attention in Serbia in the past. The research presented in this paper is the first to address biofilms at selected occurrences of mineral water in Serbia (Bogatić, Metković and Belotić in the Mačva District as well as Radaljska Banja, Lukovska Banja and Vranjska Banja) (in Serbian, banja denotes a spa town). The study period is from 2014 to 2016. The temperatures of the studied occurrences are in the 30–93.9 °C range and the chemical composition corresponds to the HCO3 − – Na++K+ and SO4 2−, HCO3 − – Na++K+ types of mineral water. One of the objectives was to examine the condition of wellheads (incrustation, biofouling and corrosion), focusing on the presence of phototrophic microorganisms whose metabolites may lead to changes in mineral water quality, yield and chemistry. Analysis by light and scanning electron microscopy provides insight into the diversity of phototrophic microorganisms that populate biofilms near the points of emergence and on wellhead. The research reveals the presence of representatives of three groups of phototrophic microorganisms: Cyanobacteria, Chlorophyta and Bacillariophyta. Cyanobacteria were the most numerous, dominated by the order Oscillatoriales with ten recorded genera, of which Leptolynbgya and Phormidium feature the largest numbers of species. The order Chroococcales are the second most numerous, with seven recorded genera, of which Gloeocapsa and Synechocystisare the most noteworthy. The largest numbers of representative taxa were noted at Radaljska Banja and Vranjska Banja, where mineral waters originate from Encrustalithostratigraphic units of igneous origin, followed by mineral water occurrences in karst aquifers (Bogatić and Belotić) and an intergranular aquifer (Metković). The smallest number of identified phototrophic microorganisms is noted at Lukovska Banja, where the origin is associated with a fractured aquifer formed in sedimentary and metamorphic rocks, with occasional diabase interbeds. Although many representative taxa are found on only one of the studied localities, such as Synechococcus bigranulatus and Pseudanabaena thermalis, those of the genera Leptolyngbya, Phormidium and Cosmarium laeve, as well as genera of the phylum Bacillariophyta, occur at several sampling sites. Principal component analysis (PCA) was used to show the relationship between documented cyanobacterial and algal taxa and environmental parameters. Key words: Serbia, mineral waters, phototrophic microorganisms, biofilm. Mineralne vode v Srbiji in razvoj fototrofnih mikrobnih združb na mestih izvirov in na ustjih vrtin Fototrofni mikroorganizmi v oblogah termalnih izvirov v Srbiji v preteklosti niso bili deležni posebne pozornosti. V članku predstavljena raziskava je prva, ki obravnava biofilme na izbranih mestih izvirov mineralnih vod v Srbiji (Bogatić, Metković in Belotić v Mačvi ter Radaljska Banja, Lukovska Banja in Vranjska Banja) (v srbskem jeziku je banja izraz za toplice). Preučevanje je potekalo med letoma 2014 in 2016. Temperature obravnavanih voda se gibljejo med 30 in 93,9 °C, glede na kemijsko sestavo pa jih uvrščamo v HCO3 − – Na++ K+ in SO4 2−, HCO3 − – Na++K+ tipe mineralne vode. Eden od ciljev raziskave je bil proučevati razmere na ustjih vrtin (inkrustacija, obrast in korozija) in se še posebej posvetiti navzočnosti fototrofnih mikroorganizmov, katerih metaboliti lahko spremenijo kakovost, izdatnost in kemizem mineralnih vod. Z analizo slik s svetlobnim in vrstičnim elektronskim mikroskopom lahko podrobneje spoznamo raznolikost fototrofnih organizmov, ki sestavljajo biofilme na mestih izvirov in na ustjih vrtin. Raziskava je pokazala obstoj predstavnikov treh skupin fototrofnih mikroorganizmov: cianobakterij ter predstavnikov debel Chlorophyta in Bacillariophyta. Cianobakterije so bile najbolj številčne, prevladovali so osebki reda Oscillatoriales z desetimi ugotovljenimi rodovi, od katerih je bilo največje število vrst iz rodov Leptolynbgya in Phormidium. Red Chroococcales je bil s sedmimi zabeleženimi rodovi drugi najbolj številčen, prevladovala sta Gloeocapsa in Synechocystis. Največreprezentativnih taksonov je bilo v Radaljski Banji in Vranjski Banji, kjer mineralne vode izvirajo iz litostratigrafskih enot vulkanskega izvora, sledijo mineralne vode iz kraškega (Bogatić in Belotić) in medzrnskega vodonosnika (Metković). Najmanjfototrofnih organizmov je bilo v vzorcu iz Lukovske Banje, kjer vode izvirajo iz razpoklinskih vodonosnikov v sedimentnih in metamorfnih kamninah z vmesnimi lečami diabaza. Čeprav soštevilne reprezentativne taksone našli le na eni od proučevanih lokacij, kot na primer Synechococcus bigranulatus in Pseudanabaena thermalis, se tisti iz rodu Leptolyngbya, Phormidium in Cosmarium laeve in predstavniki več rodov, ki pripadajo deblu Bacillariophyta, pojavljajo na več vzorčnih mestih. Za ugotavljanje odvisnosti med taksoni cianobakterij in alg ter okoljskimi parametri so uporabili analizo glavnih komponent.Ključne besede: Srbija, mineralne vode, fototrofni mikroorganizmi, biofilm.
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