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1.
Ecotoxicol Environ Saf ; 184: 109655, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31525561

RESUMO

This study investigated the effects of Cupriavidus sp. strain Cd02-mediated increase on biosorption and bioprecipitation of Cd2+ during the 144-h cultivation time as well as evaluated effectivenesses of changing soil pH and bioavailability of cadmium after bioaugmentation of strain Cd02 into Cd-contaminated paddy soil for 15 days. Results showed that strain Cd02-induced pH increase of the culture medium (from 7.40 to 8.68) facilitated biosorption of Cd2+ on Cd02 cell surface (4.82 mg/mg) and extracellular bioprecipitation in form of cadmium carbonate (3.07 mg/mg). Also, the pH values of Cd-contaminated paddy soil increased by 1.41 units after strain Cd02 was applied for 15 days, which thereby promoted the decrease of exchangeable fraction of Cd2+ by 6.5% in the tested paddy soil. Meanwhile, strain Cd02 could prosperously live in paddy soils after bioaugmentation. These results suggest that strain Cd02 may be applicable for bioremediation of the heavy metal-contaminated soils by bioaugmentation.


Assuntos
Cádmio/análise , Carbonatos/análise , Cupriavidus/metabolismo , Poluentes do Solo/análise , Solo/química , Biodegradação Ambiental , Disponibilidade Biológica , Biomineralização , Cádmio/metabolismo , Carbonatos/metabolismo , Cupriavidus/crescimento & desenvolvimento , Concentração de Íons de Hidrogênio , Oryza/crescimento & desenvolvimento , Poluentes do Solo/metabolismo
2.
Sci Total Environ ; 692: 784-790, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31539985

RESUMO

Microalgae used in wastewater treatment may be applied to soil as a biofertilizer - this is a novel strategy for recycling of nutrients in the circular economy. There is little information about how the application of large concentrations of unicellular algae to soil will affect soil biochemistry, particularly when they are living algal cells with the potential to form a soil biofilm, whereas soil biofilms are expected to influence plant-microbe interactions. Chlorophyte unicellular algae of the Chlorella genera are widely employed in algae-based water treatment systems, and Chlorella sorokiniana has proven to be highly adaptable for this purpose. We applied three filtrates of a Chlorella sorokiniana culture to soil microcosms, separating the microalgae from other microorganisms, as well as a sterile control filtrate without biological activity. Bacterial biomass in soils receiving the non-filtered (NF) slurry with viable algal cells was increased by 25% in the soil surface (0-8mm), and heterotrophic activity in those treatments increased as measured by CO2-C evolution. Total soil carbon concentrations were increased in the treatment with living algal cells (NF) by 0.4%, but no differences in organic carbon were measured; instead, it was found that inorganic carbon (CaCO3) concentrations increased by 0.6% in the NF treatment only. Soil phosphorus availability was also reduced in the surface of the NF treatment, indicating an increased biological demand. The results show that, when applied to soil, microalgae and associated biofilms will have relevant direct and indirect effects on soil quality and nutrients of agricultural importance.


Assuntos
Fenômenos Fisiológicos Bacterianos , Carbonatos/metabolismo , Precipitação Química , Microalgas/fisiologia , Fósforo/metabolismo , Solo/química , Bactérias/metabolismo , Fertilizantes/análise , Microbiologia do Solo
3.
Int J Mol Sci ; 20(17)2019 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-31461878

RESUMO

Previously, we detected a higher degree of mineralization in fetal calf serum (FCS) compared to serum-free cultured jaw periosteum derived osteoprogenitor cells (JPCs). By Raman spectroscopy, we detected an earlier formation of mineralized extracellular matrix (ECM) of higher quality under serum-free media conditions. However, mineralization potential remained too low. In the present study, we aimed to investigate the biochemical composition and subsequent biomechanical properties of the JPC-formed ECM and minerals under human platelet lysate (hPL) and FCS supplementation. JPCs were isolated (n = 4 donors) and expanded under FCS conditions and used in passage five for osteogenic induction under both, FCS and hPL media supplementation. Raman spectroscopy and Alizarin Red/von Kossa staining were employed for biochemical composition analyses and for visualization and quantification of mineralization. Osteocalcin gene expression was analyzed by quantitative PCR. Biomechanical properties were assessed by using atomic force microscopy (AFM). Raman spectroscopic measurements showed significantly higher (p < 0.001) phosphate to protein ratios and in the tendency, lower carbonate to phosphate ratios in osteogenically induced JPCs under hPL in comparison to FCS culturing. Furthermore, higher crystal sizes were detected under hPL culturing of the cells. With respect to the ECM, significantly higher ratios of the precursor protein proline to hydroxyproline were detected in hPL-cultured JPC monolayers (p < 0.001). Additionally, significantly higher levels (p < 0.001) of collagen cross-linking were calculated, indicating a higher degree of collagen maturation in hPL-cultured JPCs. By atomic force microscopy, a significant increase in ECM stiffness (p < 0.001) of FCS cultured JPC monolayers was observed. The reverse effect was measured for the JPC formed precipitates/minerals. Under hPL supplementation, JPCs formed minerals of significantly higher stiffness (p < 0.001) when compared to the FCS setting. This study demonstrates that hPL culturing of JPCs leads to the formation of an anorganic material of superior quality in terms of biochemical composition and mechanical properties.


Assuntos
Cálcio/metabolismo , Arcada Osseodentária/citologia , Osteoblastos/metabolismo , Periósteo/metabolismo , Fosfatos/metabolismo , Calcificação Fisiológica , Carbonatos/metabolismo , Células Cultivadas , Colágeno/metabolismo , Meios de Cultura/farmacologia , Matriz Extracelular/metabolismo , Humanos , Osteoblastos/efeitos dos fármacos , Osteoblastos/ultraestrutura , Osteocalcina/genética , Osteocalcina/metabolismo , Periósteo/citologia , Prolina/metabolismo
4.
Prep Biochem Biotechnol ; 49(7): 727-734, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31017519

RESUMO

The accurate estimation of kinetic parameters is of fundamental importance for biochemical studies for research and industry. In this paper, we demonstrate the application of a modular microfluidic system for execution of enzyme assays that allow determining the kinetic parameters of the enzymatic reactions such as Vmax - the maximum rate of reaction and KM - the Michaelis constant. For experiments, the fluorogenic carbonate as a probe for a rapid determination of the kinetic parameters of hydrolases, such as lipases and esterases, was used. The microfluidic system together with the method described yields the kinetic constants calculated from the concentration of enzymatic product changes via a Michaelis-Menten model using the Lambert function W(x). This modular microfluidic system was validated on three selected enzymes (hydrolases).


Assuntos
Ensaios Enzimáticos/instrumentação , Esterases/metabolismo , Dispositivos Lab-On-A-Chip , Lipase/metabolismo , Carbonatos/análise , Carbonatos/metabolismo , Desenho de Equipamento , Esterases/análise , Fluorescência , Corantes Fluorescentes/análise , Corantes Fluorescentes/metabolismo , Cinética , Lipase/análise
5.
World J Microbiol Biotechnol ; 35(4): 58, 2019 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-30900009

RESUMO

The industrialization and growth of human population has increased the release and accumulation of metals and metalloids in the environment. Bioaccumulation and exposure to these elements have been associated with different types of diseases and cancer, thus looking for alternatives that decrease their bioavailability in the environment is crucial. Microbiologically induced carbonates precipitation (MICP) has been proposed as a potential bioremediation method to immobilize contaminating metals and metalloids. Studies published to date have mainly used ureolytic bacteria, reporting metal(loid)s removal percentages up to 100% for some toxic elements, thus demonstrating the effectiveness of this treatment. Various genera of bacteria, particularly Gram-positive, have been reported with MICP abilities. More recently, fungi have also been proposed as a viable alternative for the removal of these toxic elements by carbonate precipitation. This mini-review presents updated information about the main studies carried out to date using different types of microorganisms that perform MICP to decrease the environmental bioavailability of toxic metals and metalloids through the formation of metallic carbonates.


Assuntos
Carbonatos/metabolismo , Imobilização , Metaloides/metabolismo , Metais Pesados/metabolismo , Arsênico , Bactérias/classificação , Bactérias/metabolismo , Biodegradação Ambiental , Cádmio/metabolismo , Compostos de Cromo , Fungos/classificação , Fungos/metabolismo , Intoxicação por Metais Pesados , Humanos , Metaloides/toxicidade , Metais Pesados/toxicidade , Compostos de Potássio , Solo/química , Microbiologia do Solo , Poluentes do Solo/metabolismo , Sulfatos , Ureia/metabolismo , Urease/metabolismo , Poluentes Químicos da Água
6.
Microb Biotechnol ; 12(3): 515-527, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30838803

RESUMO

Microbiome plays a key role in determining soil suppressiveness against invading pathogens. Our previous study revealed that microbial community of bulk soil could be manipulated by lime and ammonium bicarbonate fumigation followed by biofertilizer application. However, the assembly of microbial community suppressive to banana Panama disease in the rhizosphere is still unclear. In this study, we used high-throughput sequencing and quantitative PCR to explore the assembly of rhizosphere microbiome associated with banana Panama disease suppression in a two-seasonal pot experiment. We found biofertilizer applied to lime and ammonium bicarbonate fumigated soil significantly (P < 0.05) reduced the abundance of rhizosphere Fusarium oxysporum compared to biofertilizer applied to non-fumigated soil. Principal coordinate analysis revealed that biofertilizer applied to lime and ammonium bicarbonate fumigated soil re-shaped the rhizosphere bacterial community composition by increasing the phylogenetic relatedness, and stimulating indigenous microbes, for example, Gemmatimonas, Sphingomonas, Pseudomonas, Lysobacter and Bacillus. Co-occurrence analysis revealed that potential species involved in disease suppression were more interrelated in disease-suppressive soils. Taken together, lime and ammonium bicarbonate fumigation followed by biofertilizer application could induce banana rhizosphere to assemble beneficial microbes dominated consortia to suppress banana Panama disease.


Assuntos
Biota/efeitos dos fármacos , Compostos de Cálcio/metabolismo , Carbonatos/metabolismo , Fertilizantes , Fumigação , Óxidos/metabolismo , Doenças das Plantas/prevenção & controle , Microbiologia do Solo , Bactérias/classificação , Bactérias/genética , Fusarium/isolamento & purificação , Sequenciamento de Nucleotídeos em Larga Escala , Musa/crescimento & desenvolvimento , Reação em Cadeia da Polimerase em Tempo Real , Rizosfera
7.
Nat Commun ; 10(1): 808, 2019 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-30778057

RESUMO

Major hydrocarbon accumulations occur in traps associated with salt domes. Whereas some of these hydrocarbons remain to be extracted for economic use, significant amounts have degraded in the subsurface, yielding mineral precipitates as byproducts. Salt domes of the Gulf of Mexico Basin typically exhibit extensive deposits of carbonate that form as cap rock atop salt structures. Despite previous efforts to model cap rock formation, the details of subsurface reactions (including the role of microorganisms) remain largely unknown. Here we show that cap rock mineral precipitation occurred via closed-system sulfate reduction, as indicated by new sulfur isotope data. 13C-depleted carbonate carbon isotope compositions and low clumped isotope-derived carbonate formation temperatures indicate that microbial, sulfate-dependent, anaerobic oxidation of methane (AOM) contributed to carbonate formation. These findings suggest that AOM serves as an unrecognized methane sink that reduces methane emissions in salt dome settings perhaps associated with an extensive, deep subsurface biosphere.


Assuntos
Carbonatos/química , Sedimentos Geológicos/microbiologia , Metano/metabolismo , Anaerobiose , Carbonatos/metabolismo , Golfo do México , Louisiana , Oxirredução , Sulfatos/química , Enxofre , Isótopos de Enxofre/análise , Texas
8.
Poult Sci ; 98(6): 2562-2569, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30668765

RESUMO

Bone volumes and quality are related to their hormone levels in laying hens. In this study, we investigated letrozole (LZ) induced effects on the physicochemical properties of cortical bone in laying hens. After 9-wk LZ treatment, we observed that LZ could decrease estrogen level in laying hens. As a result, both the plasma tartrate-resistant acid phosphatase and bone Gla protein activities were suppressed significantly. In addition, carbonate substitution was inhibited significantly in humerus and femur confirmed by Raman spectroscopy. Meanwhile, the mineral density and yield load capacities of humerus and femur were improved. This study demonstrated that the high crystallinity and low carbonate substitution were tightly correlated with the relatively enhanced mechanical properties. Moreover, it elucidated biochemical mechanisms of estrogen in regulating mineralogical and mechanical properties of bones in laying hens.


Assuntos
Inibidores da Aromatase/farmacologia , Osso e Ossos/efeitos dos fármacos , Calcificação Fisiológica/efeitos dos fármacos , Letrozol/farmacologia , Animais , Densidade Óssea/efeitos dos fármacos , Desenvolvimento Ósseo/efeitos dos fármacos , Osso e Ossos/química , Carbonatos/metabolismo , Galinhas/metabolismo , Estrogênios/sangue , Feminino , Osteocalcina/análise , Oviposição/fisiologia , Fosfatase Ácida Resistente a Tartarato/sangue
9.
Glob Chang Biol ; 25(5): 1877-1888, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30689259

RESUMO

Ocean acidification poses a serious threat to marine calcifying organisms, yet experimental and field studies have found highly diverse responses among species and environments. Our understanding of the underlying drivers of differential responses to ocean acidification is currently limited by difficulties in directly observing and quantifying the mechanisms of bio-calcification. Here, we present Raman spectroscopy techniques for characterizing the skeletal mineralogy and calcifying fluid chemistry of marine calcifying organisms such as corals, coralline algae, foraminifera, and fish (carbonate otoliths). First, our in vivo Raman technique is the ideal tool for investigating non-classical mineralization pathways. This includes calcification by amorphous particle attachment, which has recently been controversially suggested as a mechanism by which corals resist the negative effects of ocean acidification. Second, high-resolution ex vivo Raman mapping reveals complex banding structures in the mineralogy of marine calcifiers, and provides a tool to quantify calcification responses to environmental variability on various timescales from days to years. We describe the new insights into marine bio-calcification that our techniques have already uncovered, and we consider the wide range of questions regarding calcifier responses to global change that can now be proposed and addressed with these new Raman spectroscopy tools.


Assuntos
Organismos Aquáticos/fisiologia , Calcificação Fisiológica , Água do Mar/química , Análise Espectral Raman , Animais , Organismos Aquáticos/química , Carbonatos/análise , Carbonatos/metabolismo , Concentração de Íons de Hidrogênio , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/metabolismo
10.
Nat Commun ; 10(1): 476, 2019 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-30696819

RESUMO

Eukaryotic algae rose to ecological relevance after the Neoproterozoic Snowball Earth glaciations, but the causes for this consequential evolutionary transition remain enigmatic. Cap carbonates were globally deposited directly after these glaciations, but they are usually organic barren or thermally overprinted. Here we show that uniquely-preserved cap dolostones of the Araras Group contain exceptional abundances of a newly identified biomarker: 25,28-bisnorgammacerane. Its secular occurrence, carbon isotope systematics and co-occurrence with other demethylated terpenoids suggest a mechanistic connection to extensive microbial degradation of ciliate-derived biomass in bacterially dominated ecosystems. Declining 25,28-bisnorgammacerane concentrations, and a parallel rise of steranes over hopanes, indicate the transition from a bacterial to eukaryotic dominated ecosystem after the Marinoan deglaciation. Nutrient levels already increased during the Cryogenian and were a prerequisite, but not the ultimate driver for the algal rise. Intense predatory pressure by bacterivorous protists may have irrevocably cleared self-sustaining cyanobacterial ecosystems, thereby creating the ecological opportunity that allowed for the persistent rise of eukaryotic algae to global importance.


Assuntos
Clorófitas/metabolismo , Cianobactérias/metabolismo , Sedimentos Geológicos/química , Evolução Biológica , Carbonatos/análise , Carbonatos/metabolismo , Clorófitas/crescimento & desenvolvimento , Cianobactérias/crescimento & desenvolvimento , Ecossistema , Solo/química
11.
Future Med Chem ; 11(1): 61-73, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30526059

RESUMO

Inhalation of high concentrations of carbon monoxide (CO) is known to lead to serious systemic complications and neuronal disturbances. However, it has been found that not only is CO produced endogenously, but also that low concentrations can bestow beneficial effects which may be of interest in biology and medicine. As translocation of CO through the human organism is difficult, small molecules known as CO-releasing molecules (CORMs) deliver controlled amounts of CO to biological systems, and these are of great interest from a medical point of view. These actions may prevent vascular dysfunction, regulate blood pressure, inhibit blood platelet aggregation or have anti-inflammatory effects. This review summarizes the functions of various CO-releasing molecules in biology and medicine.


Assuntos
Monóxido de Carbono/metabolismo , Portadores de Fármacos/química , Compostos Organometálicos/química , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/metabolismo , Anti-Inflamatórios/farmacologia , Antioxidantes/química , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Boranos/química , Boranos/metabolismo , Carbonatos/química , Carbonatos/metabolismo , Liberação Controlada de Fármacos , Humanos , Compostos Organometálicos/metabolismo , Compostos Organometálicos/farmacologia , Agregação Plaquetária/efeitos dos fármacos
12.
Geobiology ; 17(2): 199-222, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30548907

RESUMO

Environmental fluctuations are recorded in a variety of sedimentary archives of lacustrine depositional systems. Geochemical signals recovered from bottom sediments in closed-basin lakes are among the most sensitive paleoenvironmental indicators and are commonly used in reconstructing lake evolution. Microbialites (i.e., organosedimentary deposits accreted through microbial trapping and binding of detrital sediment or in situ mineral precipitation on organics [Palaios, 2, 1987, 241]), however, have been largely overlooked as paleoenvironmental repositories. Here, we investigate concentrically laminated mineralized microbialites from Laguna Negra, a high-altitude (4,100 m above sea level) hypersaline, closed-basin lake in northwestern Argentina, and explore the potential for recovery of environmental signals from these unique sedimentary archives. Spatial heterogeneity in hydrological regime helps define zones inside Laguna Negra, each with their own morphologically distinct microbialite type. Most notably, platey microbialites (in Zone 3A) are precipitated by evaporative concentration processes, while discoidal oncolites (in Zone 3C) are interpreted result from fluid mixing and biologically mediated nucleation. This spatial heterogeneity is reflected in petrographically distinct carbonate fabrics: micritic, botryoidal, and isopachous. Fabric type is interpreted to reflect a combination of physical and biological influences during mineralization, and paired C-isotope measurement of carbonate and organic matter supports ecological differences as a dominant control on C-isotopic evolution between zones. Laminae of Laguna Negra microbialites preserve a range of δ13 Ccarb from +5.75‰ to +18.25‰ and δ18 Ocarb from -2.04‰ to +9.28‰. Temporal trends of lower carbon and oxygen isotopic compositions suggest that the influence of CO2 degassing associated with evaporation has decreased over time. Combined, these results indicate that microbialite archives can provide data that aid in interpretation of both lake paleohydrology and paleoenvironmental change.


Assuntos
Bactérias/metabolismo , Sedimentos Geológicos/química , Lagos/química , Argentina , Carbonatos/metabolismo , Minerais/metabolismo , Isótopos de Oxigênio/metabolismo
13.
PLoS One ; 13(12): e0207305, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30566474

RESUMO

Seepage of methane (CH4) on land and in the sea may significantly affect Earth's biogeochemical cycles. However processes of CH4 generation and consumption, both abiotic and microbial, are not always clear. We provide new geochemical and isotope data to evaluate if a recently discovered CH4 seepage from the shallow seafloor close to the Island of Elba (Tuscany) and two small islands nearby are derived from abiogenic or biogenic sources and whether carbonate encrusted vents are the result of microbial or abiotic processes. Emission of gas bubbles (predominantly CH4) from unlithified sands was observed at seven spots in an area of 100 m2 at Pomonte (Island of Elba), with a total rate of 234 ml m-2 d-1. The measured carbon isotope values of CH4 of around -18‰ (VPDB) in combination with the measured δ2H value of -120‰ (VSMOW) and the inverse correlation of δ13C-value with carbon number of hydrocarbon gases are characteristic for sites of CH4 formation through abiogenic processes, specifically abiogenic formation of CH4 via reduction of CO2 by H2. The H2 for methanogenesis likely derives from ophiolitic host rock within the Ligurian accretionary prism. The lack of hydrothermal activity allows CH4 gas to become decoupled from the stagnant aqueous phase. Hence no hyperalkaline fluid is currently released at the vent sites. Within the seep area a decrease in porewater sulphate concentrations by ca. 5 mmol/l relative to seawater and a concomitant increase in sulphide and dissolved inorganic carbon (DIC) indicate substantial activity of sulphate-dependent anaerobic oxidation of methane (AOM). In absence of any other dissimilatory pathway, the δ13C-values between -17 and -5‰ in dissolved inorganic carbon and aragonite cements suggest that the inorganic carbon is largely derived from CH4. The formation of seep carbonates is thus microbially induced via anaerobic oxidation of abiotic CH4.


Assuntos
Carbonatos/química , Carbonatos/metabolismo , Metano/química , Metano/metabolismo , Anaerobiose , Sedimentos Geológicos/química , Sedimentos Geológicos/microbiologia , Ilhas , Itália
14.
Nat Commun ; 9(1): 4252, 2018 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-30315166

RESUMO

Through analysis of the Drosophila ionotropic receptors (IRs), a family of variant ionotropic glutamate receptors, we reveal that most IRs are expressed in peripheral neuron populations in diverse gustatory organs in larvae and adults. We characterise IR56d, which defines two anatomically-distinct neuron classes in the proboscis: one responds to carbonated solutions and fatty acids while the other represents a subset of sugar- and fatty acid-sensing cells. Mutational analysis indicates that IR56d, together with the broadly-expressed co-receptors IR25a and IR76b, is essential for physiological responses to carbonation and fatty acids, but not sugars. We further demonstrate that carbonation and fatty acids both promote IR56d-dependent attraction of flies, but through different behavioural outputs. Our work provides a toolkit for investigating taste functions of IRs, defines a subset of these receptors required for carbonation sensing, and illustrates how the gustatory system uses combinatorial expression of sensory molecules in distinct neurons to coordinate behaviour.


Assuntos
Carbonatos/metabolismo , Proteínas de Drosophila/metabolismo , Receptores Ionotrópicos de Glutamato/metabolismo , Animais , Comportamento Animal/fisiologia , Proteínas de Drosophila/genética , Drosophila melanogaster , Ácidos Graxos/metabolismo , Neurônios/citologia , Neurônios/metabolismo , Receptores Ionotrópicos de Glutamato/genética , Paladar/genética , Paladar/fisiologia
15.
Mar Environ Res ; 142: 141-146, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30337051

RESUMO

Ocean acidification and warming is widely reported to affect the ability of marine bivalves to calcify, but little is known about the underlying mechanisms. In particular, the response of their calcifying fluid carbonate chemistry to changing seawater carbonate chemistry remains poorly understood. The present study deciphers sources of the dissolved inorganic carbon (DIC) in the calcifying fluid of the blue mussel (Mytilus edulis) reared at two pH (8.1 and 7.7) and temperature (16 and 22 °C) levels for five weeks. Stable carbon isotopic ratios of seawater DIC, mussel soft tissues and shells were measured to determine the relative contribution of seawater DIC and metabolically generated carbon to the internal calcifying DIC pool. At pH 8.1, the percentage of seawater DIC synthesized into shell carbonate decreases slightly from 83.8% to 80.3% as temperature increases from 16 to 22 °C. Under acidified conditions, estimates of percent seawater DIC incorporation decreases clearly to 65.6% at 16 °C and to 62.3% at 22 °C, respectively. These findings indicate that ongoing ocean acidification and warming may interfere with the calcification physiology of M. edulis through interfering with its ability to efficiently extract seawater DIC to the calcifying front.


Assuntos
Carbonatos/química , Mytilus edulis/química , Água do Mar/química , Animais , Calcificação Fisiológica , Isótopos de Carbono/análise , Carbonatos/metabolismo , Concentração de Íons de Hidrogênio , Mytilus edulis/metabolismo , Oceanos e Mares
16.
Adv Appl Microbiol ; 104: 39-91, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30143252

RESUMO

Over the last 10-15 years, a new field of "biogeotechnics" has emerged as geotechnical engineers seek to find ground improvement technologies which have the potential to be lower carbon, more ecologically friendly, and more cost-effective than existing practices. This review summarizes the developments which have occurred in this new field, outlining in particular the microbial processes which have been shown to be most promising for altering the hydraulic and mechanical responses of soils and rocks. Much of the research effort in this new field has been focused on microbially induced carbonate precipitation (MICP) via ureolysis, while a comprehensive review of MICP is presented here, the developments which have been made regarding other microbial processes, including MICP via denitrification and biogenic gas generation are also presented. Furthermore, this review outlines a new area of study: the potential deployment of fungi in geotechnical applications which has until now been unexplored.


Assuntos
Bactérias/crescimento & desenvolvimento , Bactérias/metabolismo , Carbonatos/metabolismo , Fungos/crescimento & desenvolvimento , Fungos/metabolismo , Microbiologia do Solo , Desnitrificação , Gases/metabolismo
17.
Sci Rep ; 8(1): 10913, 2018 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-30026563

RESUMO

The applicability of the statistical tools coupled with artificial intelligence techniques was tested to optimize the critical medium components for the production of extracellular cholesterol oxidase (COD; an enzyme of commercial interest) from Streptomyces rimosus MTCC 10792. The initial medium component screening was performed using Placket-Burman design with yeast extract, dextrose, starch and ammonium carbonate as significant factors. Response surface methodology (RSM) was attempted to develop a statistical model with a significant coefficient of determination (R2 = 0.89847), followed by model optimization using Genetic Algorithm (GA). RSM-GA based optimization approach predicted that the combination of yeast extract, dextrose, starch and ammonium carbonate at concentrations 0.99, 0.8, 0.1, and 0.05 g/100 ml respectively, has resulted in 3.6 folds increase in COD production (5.41 U/ml) in comparison with the un-optimized medium (1.5 U/ml). COD was purified 10.34 folds having specific activity of 12.37 U/mg with molecular mass of 54 kDa. The enzyme was stable at pH 7.0 and 40 °C temperature. The apparent Michaelis constant (Km) and Vmax values of COD were 0.043 mM and 2.21 µmol/min/mg, respectively. This is the first communication reporting RSM-GA based medium optimization, purification and characterization of COD by S. rimosus isolated from the forest soil of eastern India.


Assuntos
Colesterol Oxidase/isolamento & purificação , Colesterol Oxidase/metabolismo , Streptomyces rimosus/enzimologia , Algoritmos , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/isolamento & purificação , Proteínas de Bactérias/metabolismo , Carbonatos/metabolismo , Colesterol Oxidase/química , Colesterol Oxidase/genética , Estabilidade Enzimática , Glucose/metabolismo , Modelos Estatísticos , Peso Molecular , Amido/metabolismo , Streptomyces rimosus/genética
18.
Talanta ; 188: 614-622, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-30029421

RESUMO

A new colorimetric and fluorescent chemosensor for visual determination of carbonate ions was developed by the microwave assisted solvent free synthesis of 7,8-dihydroxy-3-(4-methylphenyl) coumarin (DHMC). The structural characterization of DHMC was confirmed by microanalysis and spectroscopy methods (MALDI-TOF, FT-IR, 1H NMR, 13C NMR, and 2D HETCOR). The binding behaviors of DHMC were investigated towards various anions by UV-vis and fluorescence spectroscopy. DHMC showed a selective and sensitive fluorometric and colorimetric responses towards carbonate ion over other anions. The detection limit of CO32- was found to be 1.03 µM. Moreover, the fluorescence imaging in living cells suggests that DHMC has a great potential in the biological imaging application. It has been demonstrated that DHMC can be used as a rapid and reliable sensor for the determination of carbonate anion in a variety of practical applications.


Assuntos
Carbonatos/análise , Carbonatos/metabolismo , Colorimetria/métodos , Cumarínicos/farmacologia , Corantes Fluorescentes/farmacologia , Espectrometria de Fluorescência/métodos , Cumarínicos/síntese química , Cumarínicos/química , Fluorescência , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/química , Limite de Detecção , Modelos Químicos , Teoria Quântica , Saccharomyces cerevisiae/metabolismo
19.
Geobiology ; 16(6): 577-596, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29974603

RESUMO

Research on the early rise of oxygenic photosynthesis and eukaryotes has recently encountered a major pitfall, as some hopane and sterane biomarkers reported in Archaean rocks are the results of contamination. Following an extensive petrological framework in the Pilbara Craton, Western Australia, oil-bearing fluid inclusions and solid bitumens were identified in replacement and hydrothermal carbonate veins cross-cutting Archaean metasedimentary rocks. The 2.55-2.63 billion years old metasedimentary rocks were found to be depleted of indigenous biomarkers. Here we show novel biomarker results from the solvent extraction of the carbonate veins. Volcanic rock blanks, outside rinses, and instrumental blanks showed no biomarkers, and the surrounding rocks were metamorphosed to a sufficiently high extent to not yield any biomarkers, but the biomarkers found in the veins are most likely indigenous. Biomarkers detected include C21-22 ααα- and αßß-steranes (pregnanes), C27-29 αßß-steranes, C19-26 tricyclic terpanes, C29-30,34 αß-hopanes, C30 17α-diahopane, and trisnorhopanes, which are in the range 2-180 pg/g. The extracted organic matter is highly mature, based on the biomarker configurations and calculated vitrinite reflectance that ranges from 2.4-3.0 (methylphenanthrene index), 1.4-1.9 (methyladamantane index), and 1.4-2.3 (methyldiamantane index). As the biomarkers are highly mature and the biomarker assemblages have a distinctive pattern to each vein type the likelihood of sample contamination by recent, less mature, biomarkers from a different assemblage is unlikely. The detection of steranes suggests that molecular oxygen was available when the veins were formed, possibly between 2.2 and 1.8 billion years ago, but no evidence for oxygenic photosynthesis in the form of cyanobacterial biomarkers has been found. Carbonate minerals that seem to better preserve biomarkers, such as concretions or veins, show the growing importance of new and exciting opportunities to seek biomarkers in the early Earth rock record, and potentially on other planets. Our results demonstrate for that first time that biomarkers can be found in veins cutting through highly metamorphosed Archaean rocks, and gives an insight into ancient environments.


Assuntos
Biomarcadores/metabolismo , Cianobactérias/metabolismo , Hidrocarbonetos/metabolismo , Carbonatos/metabolismo , Sedimentos Geológicos , Fotossíntese
20.
Sci Adv ; 4(6): eaar8028, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29881778

RESUMO

There are increasing concerns that the current rate of climate change might outpace the ability of reef-building corals to adapt to future conditions. Work on model systems has shown that environmentally induced alterations in DNA methylation can lead to phenotypic acclimatization. While DNA methylation has been reported in corals and is thought to associate with phenotypic plasticity, potential mechanisms linked to changes in whole-genome methylation have yet to be elucidated. We show that DNA methylation significantly reduces spurious transcription in the coral Stylophora pistillata. Furthermore, we find that DNA methylation also reduces transcriptional noise by fine-tuning the expression of highly expressed genes. Analysis of DNA methylation patterns of corals subjected to long-term pH stress showed widespread changes in pathways regulating cell cycle and body size. Correspondingly, we found significant increases in cell and polyp sizes that resulted in more porous skeletons, supporting the hypothesis that linear extension rates are maintained under conditions of reduced calcification. These findings suggest an epigenetic component in phenotypic acclimatization that provides corals with an additional mechanism to cope with environmental change.


Assuntos
Aclimatação , Antozoários/genética , Recifes de Corais , Epigênese Genética , Concentração de Íons de Hidrogênio , Fenótipo , Animais , Antozoários/metabolismo , Carbonatos/metabolismo , Mudança Climática , Metilação de DNA , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Água do Mar , Estresse Fisiológico , Transcrição Genética
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