RESUMEN
Heavy metal (HM) pollution threatens human and ecosystem health. Current methods for remediating water contaminated with HMs are expensive and have limited effect. Therefore, bioremediation is being investigated as an environmentally and economically viable alternative. Freshwater protists Euglena gracilis and Euglena mutabilis were investigated for their tolerance to cadmium (Cd). A greater increase in cell numbers under Cd stress was noted for E. mutabilis but only E. gracilis showed an increase in Cd tolerance following pre-treatment with elevated concentrations of S or N. To gain insight regarding the nature of the increased tolerance RNA-sequencing was carried out on E. gracilis. This revealed transcript level changes among pretreated cells, and additional differences among cells exposed to CdCl2. Gene ontology (GO) enrichment analysis reflected changes in S and N metabolism, transmembrane transport, stress response, and physiological processes related to metal binding. Identifying these changes enhances our understanding of how these organisms adapt to HM polluted environments and allows us to target development of future pre-treatments to enhance the use of E. gracilis in bioremediation relating to heavy metals.
Asunto(s)
Cadmio , Nitrógeno , Azufre , Cadmio/toxicidad , Azufre/metabolismo , Azufre/farmacología , Nitrógeno/metabolismo , Biodegradación Ambiental , Euglena/metabolismo , Euglena/efectos de los fármacos , Euglena/genética , Contaminantes Químicos del Agua/toxicidad , Euglena gracilis/metabolismo , Euglena gracilis/efectos de los fármacos , Euglena gracilis/genéticaRESUMEN
Herein we describe a new photosynthetic euglenoid species found in Poland - Euglena mazurica. A large population exists in a small, eutrophic body of water located in a pasture near Mikolajki town inside the Masurian Landscape Park (covering a part of the Masurian Lake District in Poland). The unique cell shape (corkscrew-like) discerns it well from other previously described euglenoid species with metabolic cells. The new species possesses two plate-like chloroplasts each with a pyrenoid accompanied by two paramylon caps placed on either side of it (diplopyrenoids). On the phylogenetic tree, the new species is situated within the Euglena clade. Though it is a sister branch to three clades - one representing the similar Euglena agilis, characterized by its fusiform cells and two chloroplasts with diplopyrenoids, the two species are clearly morphologically and molecularly distinct.
Asunto(s)
Euglena , Euglénidos , Euglena/metabolismo , Filogenia , Polonia , FotosíntesisRESUMEN
Euglena gracilis, a model organism of the eukaryotic supergroup Discoba harbouring also clinically important parasitic species, possesses diverse metabolic strategies and an atypical electron transport chain. While structures of the electron transport chain complexes and supercomplexes of most other eukaryotic clades have been reported, no similar structure is currently available for Discoba, limiting the understandings of its core metabolism and leaving a gap in the evolutionary tree of eukaryotic bioenergetics. Here, we report high-resolution cryo-EM structures of Euglena's respirasome I + III2 + IV and supercomplex III2 + IV2. A previously unreported fatty acid synthesis domain locates on the tip of complex I's peripheral arm, providing a clear picture of its atypical subunit composition identified previously. Individual complexes are re-arranged in the respirasome to adapt to the non-uniform membrane curvature of the discoidal cristae. Furthermore, Euglena's conformationally rigid complex I is deactivated by restricting ubiquinone's access to its substrate tunnel. Our findings provide structural insights for therapeutic developments against euglenozoan parasite infections.
Asunto(s)
Euglena , Membranas Mitocondriales , Transporte de Electrón , Membranas Mitocondriales/metabolismo , Complejo IV de Transporte de Electrones/metabolismo , Metabolismo EnergéticoRESUMEN
Diesel, as a toxic and complex pollutant, is one of the main components in oily wastewater, and poses serious threats to the aquatic environment and the health of organisms. Employing environmentally friendly biostimulants to enhance the metabolic functions of microorganisms is currently the optimal choice to improve the biodegradation of oil-containing wastewater efficiency. This study takes Pseudomonas aeruginosa LNR1 as the target, analyzing the physiological responses and molecular mechanisms of biofilm formation when enhanced by the extracellular metabolites of euglena (EME) for diesel degradation. The results show that EME not only induces auto-aggregation behavior of strain LNR1, forming aerobic suspended granule biofilm, but also promotes the secretion of signaling molecules in the quorum sensing (QS) system. Transcriptomic and proteomic analyses indicate that the stimulatory effect of EME on strain LNR1 mainly manifests in biofilm formation, substance transmembrane transport, signal transduction, and other biological processes, especially the QS system in signal transduction, which plays a significant regulatory role in biofilm formation, chemotaxis, and two-component system (TCS). This study collectively unveils the molecular mechanisms of biostimulant EME inducing strain LNR1 to enhance diesel degradation from different aspects, providing theoretical guidance for the practical application of EME in oily wastewater pollution control.
Asunto(s)
Euglena , Pseudomonas aeruginosa , Pseudomonas aeruginosa/genética , Proteómica , Euglena/metabolismo , Aguas Residuales , Factores de Virulencia , Biopelículas , Perfilación de la Expresión Génica , Proteínas Bacterianas/genéticaRESUMEN
BACKGROUND: Synthetic algal-fungal and algal-bacterial cultures have been investigated as a means to enhance the technological applications of the algae. This inclusion of other microbes has enhanced growth and improved stress tolerance of the algal culture. The goal of the current study was to investigate natural microbial consortia to gain an understanding of the occurrence and benefits of these associations in nature. The photosynthetic protist Euglena mutabilis is often found in association with other microbes in acidic environments with high heavy metal (HM) concentrations. This may suggest that microbial interactions are essential for the protist's ability to tolerate these extreme environments. Our study assessed the Cd tolerance of a natural fungal-algal-bacterial (FAB) association whereby the algae is E. mutabilis. RESULTS: This study provides the first assessment of antibiotic and antimycotic agents on an E. mutabilis culture. The results indicate that antibiotic and antimycotic applications significantly decreased the viability of E. mutabilis cells when they were also exposed to Cd. Similar antibiotic treatments of E. gracilis cultures had variable or non-significant impacts on Cd tolerance. E. gracilis also recovered better after pre-treatment with antibiotics and Cd than did E. mutabilis. The recoveries were assessed by heterotrophic growth without antibiotics or Cd. In contrast, both Euglena species displayed increased chlorophyll production upon Cd exposure. PacBio full-length amplicon sequencing and targeted Sanger sequencing identified the microbial species present in the E. mutabilis culture to be the fungus Talaromyces sp. and the bacterium Acidiphilium acidophilum. CONCLUSION: This study uncovers a possible fungal, algal, and bacterial relationship, what we refer to as a FAB consortium. The members of this consortium interact to enhance the response to Cd exposure. This results in a E. mutabilis culture that has a higher tolerance to Cd than the axenic E. gracilis. The description of this interaction provides a basis for explore the benefits of natural interactions. This will provide knowledge and direction for use when creating or maintaining FAB interactions for biotechnological purposes, including bioremediation.
Asunto(s)
Cadmio , Euglena , Cadmio/farmacología , Cadmio/metabolismo , Cadmio/toxicidad , Euglena/metabolismo , Euglena/efectos de los fármacos , Euglena/genética , Bacterias/genética , Bacterias/efectos de los fármacos , Bacterias/clasificación , Bacterias/metabolismo , Bacterias/aislamiento & purificación , Consorcios Microbianos/efectos de los fármacos , Antibacterianos/farmacología , Hongos/efectos de los fármacos , Hongos/genética , Hongos/metabolismo , Antifúngicos/farmacologíaRESUMEN
BACKGROUND: Unstable generation of free radicals in the body are responsible for many degenerative diseases. A bloom forming algae Euglena tuba growing abundantly in the aquatic habitats of Cachar district in the state of Assam in North-East India was analysed for its phytochemical contents, antioxidant activity as well as free radical scavenging potentials. RESULTS: Based on the ability of the extract in ABTSâ¢+ radical cation inhibition and Fe3+ reducing power, the obtained results revealed the prominent antioxidant activity of the algae, with high correlation coefficient of its TEAC values to the respective phenolic and flavonoid contents. The extract had shown its scavenging activity for different free radicals and 41.89 ± 0.41 µg/ml, 5.83 ± 0.07 µg/ml, 278.46 ± 15.02 µg/ml and 223.25 ± 4.19 µg/ml were determined as the IC50 values for hydroxyl, superoxide, nitric oxide and hypochlorous acid respectively, which are lower than that of the corresponding reference standards. The phytochemical analysis also revealed that the phenolics, flavonoids, alkaloids, tannins and carbohydrates are present in adequate amount in the extract which was confirmed by HPLC analysis. CONCLUSIONS: The results showed that 70% methanol extract of the algae possesses excellent antioxidant and free radical scavenging properties.
Asunto(s)
Animales , Masculino , Ratones , Extractos Celulares/química , Depuradores de Radicales Libres/metabolismo , Sustancias Reductoras/metabolismo , Euglena/química , Antioxidantes/metabolismo , Oxidación-Reducción , Fenoles/análisis , Ácido Ascórbico/análisis , Taninos/análisis , Flavonoides/análisis , Peroxidación de Lípido/efectos de los fármacos , Cromanos/metabolismo , Cromatografía Líquida de Alta Presión , Metanol , Alcaloides/análisis , Microalgas , Glucosa/análisis , IndiaRESUMEN
This survey summarizes the findings concerning endogenous oscillations of three unicellular organisms: the dinophyte Gonyaulax polyedra, the ciliate Tetrahymena thermophila and the euglenophyte Euglena gracilis. All of them behave rhythmically and show the common features of zeitgeber action, differential sensitivity and temperature compensation; however, they exhibit some species-specific peculiarities that make each of them suitable for addressing particular chronobiological questions. Although ultradian rhythms have been described for Tetrahymena thermophila and Euglena gracilis, they appear under different conditions: in the first case, a modulation of the period in relation to the concentration of nutrients is observed, whereas Euglena oscillates in an ultradian and circadian fashion simultaneously. Transitions between periodic and aperiodic states can be induced in Euglena gracilis and Gonyaulax polyedra: Euglena gracilis can enter an aperiodic state after repeated exposure to short light pulses (up to I 0 sec) given at intervals of 40 min or less, whereas in Gonyaulax polyedra the circadian oscillator is arrested at temperatures below 12 degrees Celsius. In the arrhythmic state, the oscillator might be driven into singularity within the phase space of a limit cycle attractor; re-initiation from the holding point occurs by transition to a relatively precisely defined new phase. Photoperiodism as another important chronobiological phenomenon can be studied in Gonyaulax polyedra: cells enter the dormant stage of an asexual cyst under short days and a temperature below 16 degrees Celsius. This response can be mimicked by 5-methoxylated indoleamines such as melatonin and 5-methoxytryptamine, which are synthesized by this organism. Melatonin concentration exhibits an endogenous circadian rhythm characterized by a rapid increase shortly after the onset of darkness. Encystment, as induced by indoleamines, is associated with stimulations of bioluminescence. The coupling of the two processes involves, as a common element, the release of protons from an acidic vacuole.
Asunto(s)
Animales , Fotoperiodo , Relojes Biológicos/fisiología , División Celular , Dinoflagelados/fisiología , Euglena/fisiología , Tetrahymena thermophila/fisiologíaRESUMEN
Estudos de Euglenaceae pigmentadas relacionados a aspectos taxonômicos, ecológicos e sanitários foram realizados em Lagos do Parque Estadual das Fontes do Ipiranga, situado na cidade e Estado de Säo Paulo. Procurou-se comparar um ambiente que recebe grande quantidade de matéria orgânica (localizado no Parque Zoológico) com outro mais protegido (localizado no Jardim Botânico). Identificaram-se 53 táxons infragenéricos, que foram classificados em cinco gêneros (Euglena, Lepocinclis, Phacus, Strombomonas e Trachelomonas). No estudo ecológico procurou-se caracterizar o ambiente onde vive este grupo de organismos e, consequentemente, permitir o maior aproveitamento de sua potencialidade como indicadores biológicos de poluiçäo orgânica carbona da água. Constatou-se que os principais fatores físicos e químicos que interferem na proliferaçäo de Euglenaceae pigmentadas nas estaçöes 1 e 2 foram, ao que tudo indica, a temperatura da água, o pH, a amônia, o oxigênio dissolvido e a matéria orgânica carbonada, pois observou-se maior proliferaçäo dos organismos quando os valores dessas variáveis foram respectivamente, 21,5 a 23,0-C, 6,2 a 6,3, 1,7 a 1,9mg/l, 1,86 a 1,98mg e 7,3 a 11,0mg/l. Os dados obtidos do estudo sanitário foram discutidos e comparados com os da literatura, procurando-se classificar os organismos estudados em vários dos sistemas sapróbicos vigentes. Assim, sugere-se o uso eventual de Euglena communis Gojdics, Euglena polymorpha Dangeard e de Strombomonas ovalis (Playfair) Deflandre como indicadores biológicos de poluiçäo orgânica da água, desde que os valores da análise qualitativa estejam ao redor de 600org./ml.10-4