Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 64
Filtrar
1.
Sci Rep ; 12(1): 18735, 2022 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-36333406

RESUMO

Carbon capture and storage is required to meet Paris Agreement targets. Photosynthesis is nature's carbon capture technology. Drawing inspiration from lichen, we engineered 3D photosynthetic cyanobacterial biocomposites (i.e., lichen mimics) using acrylic latex polymers applied to loofah sponge. Biocomposites had CO2 uptake rates of 1.57 ± 0.08 g CO2 g-1biomass d-1. Uptake rates were based on the dry biomass at the start of the trial and incorporate the CO2 used to grow new biomass as well as that contained in storage compounds such as carbohydrates. These uptake rates represent 14-20-fold improvements over suspension controls, potentially scaling to capture 570 tCO2 t-1biomass yr-1, with an equivalent land consumption of 5.5-8.17 × 106 ha, delivering annualized CO2 removal of 8-12 GtCO2, compared with 0.4-1.2 × 109 ha for forestry-based bioenergy with carbon capture and storage. The biocomposites remained functional for 12 weeks without additional nutrient or water supplementation, whereupon experiments were terminated. Engineered and optimized cyanobacteria biocomposites have potential for sustainable scalable deployment as part of humanity's multifaceted technological stand against climate change, offering enhanced CO2 removal with low water, nutrient, and land use penalties.


Assuntos
Carbono , Cianobactérias , Dióxido de Carbono , Fotossíntese , Sequestro de Carbono , Biomassa , Água
2.
Toxicon ; 194: 63-69, 2021 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-33631138

RESUMO

Despite comprising over half of the biodiversity of living venomous vertebrates, fish venoms are comparatively understudied. Venom from the lesser weever fish (Echiichthys vipera syn. Trachinus vipera) has received only cursory attention despite containing one of the most potent venom toxins (trachinine). Literature records are further complicated by early studies combining the venom with that of the related greater weever (Trachinus draco). The current study used a chicken chorioallantoic membrane assay to investigate venom bioactivity following the application of measured quantities of crude venom to a major bilateral vein at 1 cm distance from the heart. The venom had a dose-dependent effect on survival rate and exhibited dose-dependent cardiotoxic properties at day six of development. Crude E. vipera triggered tachycardia at doses of 37.58 and 44.88 µg/µL and bradycardia at 77.4 µg/µL. The three highest doses (65.73, 77.4 and 151.24 µg/µL) caused significant mortality. These data also suggested intra-specific variation in E. vipera venom potency. Unlike a number of other piscine venoms, E. vipera venom was not haemorrhagic at the concentrations assayed.


Assuntos
Venenos de Peixe , Perciformes , Viperidae , Animais , Venenos de Peixe/toxicidade , Peixes , Peçonhas , Venenos de Víboras/toxicidade
3.
Sci Rep ; 10(1): 10918, 2020 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-32616798

RESUMO

There is a long-standing concern for the lack of reproducibility of the untargeted metabolomic approaches used in pharmaceutical research. Two types of human plasma samples were split into two batches and analyzed in two individual labs for untargeted GC-MS metabolomic profiling. The two labs used the same silylation sample preparation protocols but different instrumentation, data processing software, and database. There were 55 metabolites annotated reproducibly, independent of the labs. The median coefficient variations (CV%) of absolute spectra ion intensities in both labs were less than 30%. However, the comparison of normalized ion intensity among biological groups, were inconsistent across labs. Predicted power based on annotated metabolites was evaluated post various normalization, data transformation and scaling. For the first time our study reveals the numerical details about the variations in metabolomic annotation and relative quantification using plain inter-laboratory GC-MS untargeted metabolomic approaches. Especially we compare several commonly used post-acquisition strategies and found normalization could not strengthen the annotation accuracy or relative quantification precision of untargeted approach, instead it will impact future experimental design. Standardization of untargeted metabolomics protocols, including sample preparation, instrumentation, data processing, etc., is critical for comparison of untargeted data across labs.


Assuntos
Análise Química do Sangue/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Metabolômica/métodos , Plasma/química , Análise Química do Sangue/instrumentação , Feminino , Cromatografia Gasosa-Espectrometria de Massas/instrumentação , Humanos , Ensaio de Proficiência Laboratorial , Masculino , Metabolômica/instrumentação , Reprodutibilidade dos Testes , Software
4.
Toxicon X ; 6: 100025, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32550581

RESUMO

In comparison with other animal venoms, fish venoms remain relatively understudied. This is especially true for that of the lesser Echiichthys vipera and greater weever fish Trachinus draco which, apart from the isolation of their unique venom cytolysins, trachinine and dracotoxin, respectively, remain relatively uncharacterised. Envenomation reports mainly include mild symptoms consisting of nociception and inflammation. However, like most fish venoms, if the venom becomes systemic it causes cardiorespiratory and blood pressure changes. Although T. draco venom has not been studied since the 1990's, recent studies on E. vipera venom have discovered novel cytotoxic components on human cancer cells, but due to the scarcity of research on the molecular make-up of the venom, the molecule(s) causing this cytotoxicity remains unknown. This review analyses past studies on E. vipera and T. draco venom, the methods used in the , the venom constituents characterised, the reported symptoms of envenomation and compares these findings with those from other venomous Scorpaeniformes.

5.
Life (Basel) ; 10(3)2020 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-32213870

RESUMO

Diatom-derived oxylipins, including polyunsaturated aldehydes (PUA), are considered to have infochemical, allelochemical and bacteriostatic properties, with plausible roles as grazing deterrents and regulators of inter- and intraspecific competition. However, the extent and mechanisms of how PUA influence diatom-bacteria interactions remain unresolved. In this study, impacts on the diversity of the associated bacterial communities (microbiota) of two contrasting Skeletonema marinoi strains (a PUA and a non-PUA producer) were investigated under three nitrate conditions in batch culture. Further, the response of the culture microbiota was studied when spiked with PUA at ecologically relevant concentrations (86nM octadienal and 290nM heptadienal). Of the 741 identified OTUs, Proteobacteria was the most abundant phylum (62.10%), followed by Bacteroidetes (12.33%) and Firmicutes (6.11%). Escherichia/Shigella were the most abundant genera for all treatments. Similar communities were present in both spiked and non-spiked cultures suggesting they can tolerate PUA exposure at realistic concentrations. This study suggests that PUA are not major drivers of diatom-bacteria interactions in laboratory cultures.

6.
RSC Adv ; 10(61): 37391-37408, 2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-35521230

RESUMO

The production of methane-rich biogas from the anaerobic digestion (AD) of microalgae is limited by an unfavorable biomass carbon-to-nitrogen (C/N) ratio; however, this may be ameliorated using a co-digestion strategy with carbon-rich feedstocks. For reliable plant operation, and to improve the economics of the process, secure co-feedstock supply (ideally as a waste-stream) is important. To this end, this study investigated the feasibility of co-digesting microalgae (Chlorella vulgaris) with potato processing waste (potato discarded parts, PPWdp; potato peel, PPWp) and glycerol, while monitoring the response of the methanogenic community. In this semi-continuous study, glycerol (1 and 2% v/v) added to mixtures of C. vulgaris : PPWdp enhanced the specific methane yields the most, by 53-128%, whilst co-digestion with mixtures of C. vulgaris : PPWp enhanced the methane yields by 62-74%. The microbial communities diverged markedly over operational time, and to a lesser extent in response to glycerol addition. The acetoclast Methanosaeta was abundant in all treatments but was replaced by Methanosarcina in the potato peel with glycerol treatment due to volatile fatty acid (VFA) accumulation. Our findings demonstrate that the performance of microalgae co-digestion is substantially improved by the addition of glycerol as an additional co-feedstock. This should improve the economic case for anaerobically digesting microalgae as part of wastewater treatment processes and/or the terminal step of a microalgae biorefinery.

7.
Sci Total Environ ; 705: 135912, 2020 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-31846819

RESUMO

High energy gamma radiation is potentially hazardous to organisms, including aquatic invertebrates. Although extensively studied in a number of invertebrate species, knowledge on effects induced by gamma radiation is to a large extent limited to the induction of oxidative stress and DNA damage at the molecular/cellular level, or survival, growth and reproduction at the organismal level. As the knowledge of causal relationships between effects occurring at different levels of biological organization is scarce, the ability to provide mechanistic explanation for observed adverse effects is limited, and thus development of Adverse Outcome Pathways (AOPs) and larger scale implementation into next generation hazard and risk predictions is restricted. The present study was therefore conducted to assess the effects of high-energy gamma radiation from cobalt-60 across multiple levels of biological organization (i.e., molecular, cellular, tissue, organ and individual) and characterize the major toxicity pathways leading to impaired reproduction in the model freshwater crustacean Daphnia magna (water flea). Following gamma exposure, a number of bioassays were integrated to measure relevant toxicological endpoints such as gene expression, reactive oxygen species (ROS), lipid peroxidation (LPO), neutral lipid storage, adenosine triphosphate (ATP) content, apoptosis, ovary histology and reproduction. A non-monotonic pattern was consistently observed across the levels of biological organization, albeit with some variation at the lower end of the dose-rate scale, indicating a complex response to radiation doses. By integrating results from different bioassays, a novel pathway network describing the key toxicity pathways involved in the reproductive effects of gamma radiation were proposed, such as DNA damage-oocyte apoptosis pathway, LPO-ATP depletion pathway, calcium influx-endocrine disruption pathway and DNA hypermethylation pathway. Three novel AOPs were proposed for oxidative stressor-mediated excessive ROS formation leading to reproductive effect, and thus introducing the world's first AOPs for non-chemical stressors in aquatic invertebrates.


Assuntos
Daphnia , Animais , Feminino , Raios gama , Peroxidação de Lipídeos , Estresse Oxidativo , Reprodução , Poluentes Químicos da Água
8.
Toxicon ; 153: 12-16, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30144458

RESUMO

We examined the gene expression levels of equinatoxin and equistatin in the sea anemone Actinia equina, when reared at varying environmental temperatures for five months. Both genes were significantly downregulated at 10 °C compared to 16 °C but showed no significant change at 22 °C. This provides the first evidence of an effect of temperature on gene expression, but with no effect of increasing temperatures such as those predicted due to climate change.


Assuntos
Venenos de Cnidários/metabolismo , Proteínas/metabolismo , Anêmonas-do-Mar/metabolismo , Temperatura , Animais , Mudança Climática , Venenos de Cnidários/genética , Expressão Gênica , Proteínas/genética , Anêmonas-do-Mar/genética
9.
Food Chem ; 258: 71-78, 2018 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-29655756

RESUMO

Ulva is increasingly viewed as a food source in the world. Here, Ulva rigida was cultured at two levels of temperature (14, 18 °C), pH (7.95, 7.55, corresponding to low and high pCO2), and nitrate conditions (6 µmol L-1, 150 µmol L-1), to investigate the effects of ocean warming, acidification, and eutrophication on food quality of Ulva species. High temperature increased the content of each amino acid. High nitrate increased the content of all amino acids except aspartic acid and cysteine. High temperature, pCO2, and nitrate also increased the content of most fatty acids. The combination of high temperature, pCO2, and nitrate increased the swelling capacity, water holding capacity, and oil holding capacity by 15.60%, 7.88%, and 16.32% respectively, compared to the control. It seems that the future ocean environment would enhance the production of amino acid and fatty acid as well as the functional properties of Ulva species.


Assuntos
Aquecimento Global , Ulva/química , Aminoácidos/análise , Dióxido de Carbono/química , Cromatografia Líquida de Alta Pressão , Ácidos Graxos/análise , Ácidos Graxos/química , Concentração de Íons de Hidrogênio , Nitratos/química , Oceanos e Mares , Espectrometria de Massas em Tandem , Temperatura , Ulva/metabolismo
11.
Curr Top Med Chem ; 17(24): 2716-2739, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28685690

RESUMO

Untargeted metabolomics is a promising approach for reducing the significant attrition rate for discovering and developing drugs in the pharmaceutical industry. This review aims to highlight the practical decision-making value of untargeted metabolomics for the advancement of drug candidates in drug discovery/development including potentially identifying and validating novel therapeutic targets, creating alternative screening paradigms, facilitating the selection of specific and translational metabolite biomarkers, identifying metabolite signatures for the drug efficacy mechanism of action, and understanding potential drug-induced toxicity. The review provides an overview of the pharmaceutical process workflow to discover and develop new small molecule drugs followed by the metabolomics process workflow that is involved in conducting metabolomics studies. The pros and cons of the major components of the pharmaceutical and metabolomics workflows are reviewed and discussed. Finally, selected untargeted metabolomics literature examples, from primarily 2010 to 2016, are used to illustrate why, how, and where untargeted metabolomics can be integrated into the drug discovery/preclinical drug development process.


Assuntos
Descoberta de Drogas , Metabolômica , Humanos
12.
Curr Top Med Chem ; 17(24): 2791-2804, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28685696

RESUMO

We have developed a targeted metabolomics screen which consists of using two isotopically labeled glucose compounds to conduct a dual oral glucose tolerance test in rats. This dual isotopic oral glucose tolerance test (DIS-OGTT) can be used to select drug candidates that have "on"- target or have "off"-target effects on oral glucose absorption, hepatic glucose production or glucose disposal. The DIS-OGTT assay utilized intravenously administered [6-13C1-6, 6'-2H2]-glucose and orally administered [U-13C6] glucose to monitor glucose homeostasis. In the experiment, a constant intravenous dose of [6-13C1-6, 6'-2H2] glucose was converted in vivo to a series of [M+1] glucose isotopomers and unlabeled [M] glucose via gluconeogenesis while the orally administered [U-13C6] glucose was converted to a series of [M+3] and [M+2] glucose isotopomers via gluconeogenesis. The detection platform of the assay was based on a negative mode electrospray ionization liquid chromatography tandem mass spectrometry method where the deprotonated glucose anion and its various isotopomers were quantitated in rat plasma using multiple reaction monitoring techniques. The in vivo rat DIS-OGTT assay was a sensitive method for understanding drug candidates underlying postprandial effects on glucose absorption, hepatic glucose production, and insulin controlled glucose disposal. Since glucose derivatization was not required for this assay, a higher sample throughput DIS-OGTT was achieved.


Assuntos
Avaliação Pré-Clínica de Medicamentos , Glucose/química , Glucose/metabolismo , Homeostase , Metabolômica , Animais , Isótopos de Carbono/análise , Isótopos de Carbono/metabolismo , Teste de Tolerância a Glucose , Masculino , Ratos , Ratos Sprague-Dawley , Urânio/análise , Urânio/metabolismo
13.
Mar Pollut Bull ; 122(1-2): 297-305, 2017 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-28662977

RESUMO

Anthropogenic noise is a significant pollutant of the world's oceans, affecting behavioural and physiological traits in a range of species, including anti-predator behaviours. Using the open field test, we investigated the effects of recordings of piling and drilling noise on the anti-predator behaviour of captive juvenile European seabass in response to a visual stimulus (a predatory mimic). The impulsive nature of piling noise triggered a reflexive startle response, which contrasted the behaviour elicited by the continuous drilling noise. When presented with the predatory mimic, fish exposed to both piling and drilling noise explored the experimental arena more extensively than control fish exposed to ambient noise. Fish under drilling and piling conditions also exhibited reduced predator inspection behaviour. Piling and drilling noise induced stress as measured by ventilation rate. This study provides further evidence that the behaviour and physiology of European seabass is significantly affected by exposure to elevated noise levels.


Assuntos
Bass , Comportamento Animal , Ruído , Animais
14.
Mar Environ Res ; 127: 126-136, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28410750

RESUMO

Exposure to synthetic chemicals is a key environmental challenge faced by aquatic organisms. The time and dose effects of the pharmaceuticals diclofenac, ibuprofen, and sildenafil citrate on sperm motility and successful fertilisation are studied using the echinoderms, Asterias rubens and Psammechinus miliaris, and the polychaete worm Arenicola marina, all important components of the marine benthos. Motility was reduced for all species when exposed to diclofenac concentrations ≥0.1 µg/L. Exposure to ≥1.0 µg/L of ibuprofen affected only P. miliaris gametes and fertilisation success of A. marina. A. rubens and P. miliaris sperm increased in both percentage motility and swimming velocity when exposed to sildenafil citrate at concentrations ≥18 and ≥ 50 ng/L, respectively. Pre-incubation of sperm with sildenafil citrate significantly increased fertilisation success in A. rubens and P. miliaris but not in A. marina. Pre-incubated A. rubens oocytes fertilised successfully in ibuprofen. According to EU Directive 93/67/EEC, diclofenac is classified as a very toxic substance to gametes of A. rubens, P. miliaris, and A. marina (EC50 = 100-1000 µg/L) while ibuprofen is classified as very toxic to gametes of P. miliaris but non-toxic to gametes of A. marina (EC50 > 10,000 µg/L). The present study indicates that diclofenac exposure may have negative impacts on invertebrate reproductive success, whereas ibuprofen potentially may compromise P. miliaris reproduction. This study provides a valuable insight into the mechanisms that allow marine invertebrates to survive and reproduce in contaminated and changing habitats.


Assuntos
Organismos Aquáticos/fisiologia , Diclofenaco/toxicidade , Ibuprofeno/toxicidade , Invertebrados/fisiologia , Citrato de Sildenafila/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Equinodermos/fisiologia , Monitoramento Ambiental , Poliquetos/fisiologia , Reprodução/efeitos dos fármacos
15.
SLAS Discov ; 22(4): 433-439, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28328322

RESUMO

Monoacylglycerol acyltransferase enzymes (MGAT1, MGAT2, and MGAT3) convert monoacylglycerol to diacylglycerol (DAG). MGAT1 and MGAT2 are both implicated in obesity-related metabolic diseases. Conventional MGAT enzyme assays use radioactive substrates, wherein the product of the MGAT-catalyzed reaction is usually resolved by time-consuming thin layer chromatography (TLC) analysis. Furthermore, microsomal membrane preparations typically contain endogenous diacylglycerol acyltransferase (DGAT) from the host cells, and these DGAT activities can further acylate DAG to form triglyceride (TG). Our mass spectrometry (liquid chromatography-tandem mass spectrometry, or LC/MS/MS) MGAT2 assay measures human recombinant MGAT2-catalyzed formation of didecanoyl-glycerol from 1-decanoyl-rac-glycerol and decanoyl-CoA, to produce predominantly 1,3-didecanoyl-glycerol. Unlike 1,2-DAG, 1,3-didecanoyl-glycerol is proved to be not susceptible to further acylation to TG. 1,3-Didecanoyl-glycerol product can be readily solubilized and directly subjected to high-throughput mass spectrometry (HTMS) without further extraction in a 384-well format. We also have established the LC/MS/MS MGAT activity assay in the intestinal microsomes from various species. Our assay is proved to be highly sensitive, and thus it allows measurement of endogenous MGAT activity in cell lysates and tissue preparations. The implementation of the HTMS MGAT activity assay has facilitated the robust screening and evaluation of MGAT inhibitors for the treatment of metabolic diseases.


Assuntos
Diglicerídeos/análise , Inibidores Enzimáticos/análise , Ensaios de Triagem em Larga Escala , N-Acetilglucosaminiltransferases/antagonistas & inibidores , Acil Coenzima A/metabolismo , Animais , Chlorocebus aethiops , Cromatografia Líquida/métodos , Diglicerídeos/antagonistas & inibidores , Diglicerídeos/biossíntese , Cães , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Haplorrinos , Humanos , Intestinos/efeitos dos fármacos , Intestinos/enzimologia , Cinética , Camundongos , Microssomos/efeitos dos fármacos , Microssomos/enzimologia , N-Acetilglucosaminiltransferases/metabolismo , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes/metabolismo , Espectrometria de Massas em Tandem/métodos
16.
Anal Biochem ; 524: 68-75, 2017 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-27665677

RESUMO

Monoacylglycerol acyltransferase 2 (MGAT2) catalyzes the synthesis of diacylglycerol (DAG) from free fatty acids (FFA) and sn-monoacylglycerol (MG), the two major hydrolysis products of dietary fat. To demonstrate MGAT2-mediated cellular activity of triglyceride (TG) synthesis, we utilized 1-oleoyl-glycerol-d5 as a substrate to trace MGAT2-driven 1-oleoyl-glycerol-d5 incorporation into TG in HEK293 cells stably expressing human MGAT2. The oleoyl-glycerol-d5 incorporated major TG species were then quantified by liquid chromatography electrospray ionization tandem mass spectrometry (LC/ESI/MS/MS) in a 96-well format. Conventional MGAT2 target-engagement in vivo assays measure the elevation of total plasma TG by orally dosing a bolus of TG oil. We developed a novel LC/ESI/MS/MS-based fat absorption assay to assess the ability of MGAT2 inhibitors to inhibit fat absorption in CD1 mice by a meal tolerance test consisting of a mixture of liquid Boost plus® and 0.59 g/kg U13C-TG oil. The newly resynthesized plasma heavy TGs containing three 13C in the glycerol backbone and two U13C-acyl-chains, which represented the digested, absorbed and resynthesized TGs, were then quantitated by LC/ESI/MS/MS. With this assay, we identified a potent MGAT2 inhibitor that blocked MGAT2-mediated activity in vitro and in vivo. The use of 1-oleoyl-glycerol-d5 and U13C-TG oil followed by LC/ESI/MS/MS detection of stable-isotopic labeled DAG, TG, or glycerol provides a wide range of applications to study pathophysiological regulation of the monoacylglycerol pathway and MGAT2 activity.


Assuntos
Glicerídeos/metabolismo , Glicerol/metabolismo , Metabolismo dos Lipídeos , N-Acetilglucosaminiltransferases/metabolismo , Espectrometria de Massas em Tandem/métodos , Animais , Cromatografia Líquida/métodos , Inibidores Enzimáticos/farmacologia , Células HEK293 , Humanos , Camundongos
17.
Mar Pollut Bull ; 114(1): 439-447, 2017 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-27733288

RESUMO

The incidence and severity of extraordinary macroalgae blooms (green tides) are increasing. Here, climate change (ocean warming and acidification) impacts on life history and biochemical responses of a causative green tide species, Ulva rigida, were investigated under combinations of pH (7.95, 7.55, corresponding to lower and higher pCO2), temperature (14, 18°C) and nitrate availability (6 and 150µmolL-1). The higher temperature accelerated the onset and magnitude of gamete settlement. Any two factor combination promoted germination and accelerated growth in young plants. The higher temperature increased reproduction, which increased further in combination with elevated pCO2 or nitrate. Reproductive success was highest (64.4±5.1%) when the upper limits of all three variables were combined. Biochemically, more protein and lipid but less carbohydrate were synthesized under higher temperature and nitrate conditions. These results suggest that climate change may cause more severe green tides, particularly when eutrophication cannot be effectively controlled.


Assuntos
Eutrofização , Ulva/fisiologia , Mudança Climática , Germinação , Concentração de Íons de Hidrogênio , Metabolismo dos Lipídeos , Nitratos/metabolismo , Proteínas/metabolismo , Reprodução , Alga Marinha/crescimento & desenvolvimento , Temperatura , Ulva/crescimento & desenvolvimento , Reino Unido
18.
Sci Rep ; 6: 38850, 2016 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-27941918

RESUMO

Deposit-feeding invertebrates are proposed bioremediators in microbial-driven sediment-based aquaculture effluent treatment systems. We elucidate the role of the sediment reduction-oxidation (redox) regime in structuring benthic bacterial communities, having direct implications for bioremediation potential and deposit-feeder nutrition. The sea cucumber Holothuria scabra was cultured on sediments under contrasting redox regimes; fully oxygenated (oxic) and redox stratified (oxic-anoxic). Taxonomically, metabolically and functionally distinct bacterial communities developed between the redox treatments with the oxic treatment supporting the greater diversity; redox regime and dissolved oxygen levels were the main environmental drivers. Oxic sediments were colonised by nitrifying bacteria with the potential to remediate nitrogenous wastes. Percolation of oxygenated water prevented the proliferation of anaerobic sulphate-reducing bacteria, which were prevalent in the oxic-anoxic sediments. At the predictive functional level, bacteria within the oxic treatment were enriched with genes associated with xenobiotics metabolism. Oxic sediments showed the greater bioremediation potential; however, the oxic-anoxic sediments supported a greater sea cucumber biomass. Overall, the results indicate that bacterial communities present in fully oxic sediments may enhance the metabolic capacity and bioremediation potential of deposit-feeder microbial systems. This study highlights the benefits of incorporating deposit-feeding invertebrates into effluent treatment systems, particularly when the sediment is oxygenated.


Assuntos
Aquicultura/métodos , Bactérias/isolamento & purificação , Biodegradação Ambiental , Sedimentos Geológicos/microbiologia , Holothuria/crescimento & desenvolvimento , Animais , Bactérias/classificação , Bactérias/genética , Bactérias/metabolismo , Biodiversidade , Biomassa , Genes Bacterianos , Metagenômica , Oxirredução , Oxigênio/análise , Ribotipagem , Temperatura
19.
Front Microbiol ; 7: 104, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26903983

RESUMO

The genus Pseudoalteromonas constitutes an ecologically significant group of marine Gammaproteobacteria with potential biotechnological value as producers of bioactive compounds and of enzymes. Understanding their roles in the environment and bioprospecting for novel products depend on efficient ways of identifying environmental isolates. Matrix Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) biotyping has promise as a rapid and reliable method of identifying and distinguishing between different types of bacteria, but has had relatively limited application to marine bacteria and has not been applied systematically to Pseudoalteromonas. Therefore, we constructed a MALDI-TOF MS database of 31 known Pseudoalteromonas species, to which new isolates can be compared by MALDI-TOF biotyping. The ability of MALDI-TOF MS to distinguish between species was scrutinized by comparison with 16S rRNA gene sequencing. The patterns of similarity given by the two approaches were broadly but not completely consistent. In general, the resolution of MALDI-TOF MS was greater than that of 16S rRNA gene sequencing. The database was tested with 13 environmental Pseudoalteromonas isolates from UK waters. All of the test strains could be identified to genus level by MALDI-TOF MS biotyping, but most could not be definitely identified to species level. We conclude that several of these isolates, and possibly most, represent new species. Thus, further taxonomic investigation of Pseudoalteromonas is needed before MALDI-TOF MS biotyping can be used reliably for species identification. It is, however, a powerful tool for characterizing and distinguishing among environmental isolates and can make an important contribution to taxonomic studies.

20.
Sci Rep ; 5: 10036, 2015 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-25963242

RESUMO

Accurate and defendable taxonomic identification of microalgae strains is vital for culture collections, industry and academia; particularly when addressing issues of intellectual property. We demonstrate the remarkable effectiveness of Matrix Assisted Laser Desorption Ionisation Time of Flight Mass Spectrometry (MALDI-TOF-MS) biotyping to deliver rapid and accurate strain separation, even in situations where standard molecular tools prove ineffective. Highly distinctive MALDI spectra were obtained for thirty two biotechnologically interesting Dunaliella strains plus strains of Arthrospira, Chlorella, Isochrysis, Tetraselmis and a range of culturable co-occurring bacteria. Spectra were directly compared with genomic DNA sequences (internal transcribed spacer, ITS). Within individual Dunaliella isolates MALDI discriminated between strains with identical ITS sequences, thereby emphasising and enhancing knowledge of the diversity within microalgae culture collections. Further, MALDI spectra did not vary with culture age or growth stage during the course of the experiment; therefore MALDI presents stable and accurate strain-specific signature spectra. Bacterial contamination did not affect MALDI's discriminating power. Biotyping by MALDI-TOF-MS will prove effective in situations wherein precise strain identification is vital, for example in cases involving intellectual property disputes and in monitoring and safeguarding biosecurity. MALDI should be accepted as a biotyping tool to complement and enhance standard molecular taxonomy for microalgae.


Assuntos
Clorófitas , Microalgas , Proteínas de Plantas , Proteômica , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Clorófitas/classificação , Clorófitas/genética , Clorófitas/metabolismo , Microalgas/classificação , Microalgas/genética , Microalgas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...