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Universidad de Buenos Aires | UBA · Department of Biodiversity and Experimental Biology

A taxonomic study of the genus Trachelomonas (Euglenophyta) was undertaken in temporary ponds on Menorca Island, Spain, called “basses”. Among the 13 studied ponds, this genus was found in only one, called Verda B. A light and scanning electron microscope study of the samples taken from this body enabled the identification of 28 taxa, 26 of which w...

A floristic and ultrastructural study on loricated Euglenophyta was made in several freshwater bodies from the Amazonian and Caribbean regions of Colombia. A total of 114 taxa were recorded, 93 belonged to the genus Trachelomonas Ehr., and 21 to Strombomonas Defl. From the total taxa determined, 73 were recorded for the first time for Colombia, 19...

In order to test if orally supplied Euglena sp. cells modulate the physiological status of bivalves during bioremediation procedures, we evaluated the effect of Euglena gracilis diet on the immune response, oxidative balance and metabolic condition of Diplodon chilensis exposed to sewage water pollution. Mussels were fed for 90 days with E. gracili...

Euglenoids are a group of predominantly free-living unicellular microorganisms that mostly live in freshwater bodies but can also be found in marine and brackish waters. These organisms have a characteristic that distinguishes them form the other protists: they are covered by a surface pellicle formed by S-shaped overlapping bands which resemble a...

In a recent paper we have investigated, from an electromagnetic point of view, the role played by the pellicle of Euglenoids -unicellular aquatic organisms- in the protection of the cell against UV radiation.14 By modelling the pellicle as a diffraction grating, we computed the electromagnetic response of different species that exhibit different be...

We evaluated the modulating effect of long-term feeding with lyophilized Euglena gracilis cells on immune response, oxidative balance and metabolic condition of the freshwater mussel Diplodon chilensis. Mussels, previously fed with Scenedesmus vacuolatus (SV) or E. gracilis (EG) for 90 days, were challenged with an environmentally relevant concentr...

Euglenoids are unicellular aquatic organisms. These microalgae show a typical surface structure that distinguishes them from the other protists. Most cells are naked and bounded by a plasma membrane surrounded by a pellicle formed by overlapping bands. It is well known that all terrestrial and aquatic organisms are exposed to UV-A and UV-B radiatio...

Morphological and ultrastructural changes induced by exposure to excess of organic matter were analyzed in Phacus brachykentron (Pochm.). The cells were isolated from sites in Matanza River, Buenos Aires, Argentina, which have a high degree of organic matter contamination coming from waste waters discharges of the meat industry. Master strains were...

Background: Euglena gracilis is a microalgae with a wide range of nutritional requirements, suggesting the existence of diverse physiological patterns. The aim of this work is to carry out a study about secondary metabolites biosynthesis on two strains of E. gracilis cultured in vitro. Methods: Extracts from a Euglena gracilis (Klebs) commercial st...

A fl oristic and ultrastructural study on naked green Euglenophyta was performed in the Amazonian and Caribbean regions of Colombia, where a large number of taxa are contained in several freshwater bodies. A total of 37 taxa were recorded, 1 belonging to the genus Cryp-toglena Ehr., 9 to Lepocinclis Perty, 1 to Monomorphina Meresch., and 26 to Phac...

Oxidative stress parameter and antioxidant defense compound as well as enzyme activity were studied in relation to different Cr(VI) concentrations (0, 10, 20, 40 μM) in two strains of Euglena gracilis, one isolated from a polluted river (MAT) and the other acquired from a culture collection (UTEX). Chromium toxicity was measured in the auxotrophic...

This bioassay was designed with the aim of exploring the responses of two wild planktonic microalgae exposed in situ (72 h) as indicators of the changes in water quality. Monocultures of both strains within dialysis membrane bags were placed at two sites in a small lowland stream. Site 1 is located at a suburban area with low horticultural activity...

This study provides valuable information on the ultrastructure and environmental conditions of the Trachelomonas Ehr. (Euglenophyceae) genus in the Guadalupe Dam, a eutrophic reservoir located in the suburbs of Mexico City, which receives a considerable volume of wastewaters. Specimens were collected at surface level between November 2005 and May 2...

A floristic and ultrastructural study on Trachelomonas was made in the piedmont region of central New Jersey, USA, where a large number of euglenoid taxa are contained in several freshwater bodies. Abundant and unusual loricated species were found during the observations of samples from these ponds. From the forty-seven taxa determined, eighteen ar...

Twenty-six taxa of the genus Strombomonas Deflandre (Euglenophyta) were determined from samples collected from several freshwater bodies located in the Piedmont region of central New Jersey, USA. In addition, twelve taxa were examined in detail by scanning electron microscopy (SEM). On the basis of these observations one new species is proposed: S....

Eighty nine taxa of Euglenophyta, sampled in Rodríguez Stream, Buenos Aires, Argentina, 2 belonging to the genus Euglena Ehr., 7 to Lepocinclis Perty, 14 to Phacus Duj., 40 to Strombomonas Defl. and 26 to Trachelomonas Ehr. have been identified. Besides 12 loricate taxa were examined by scanning electron microscopy (SEM). Details of their envelope...

In microorganisms and plants, chromium (Cr) is not essential for any metabolic process, and can ultimately prove highly deleterious. Due to its widespread industrial use, chromium has become a serious pollutant in diverse environmental settings. The presence of Cr leads to the selection of specific algal populations able to tolerate high levels of...

Studies on taxonomy and seasonal variations of density and biomass were carried out over a year on epibiont algae on planktic microcrustaceans from a subtropical shallow lake (Corrientes, Argentina). Four taxa, 3 Chlorophyta and 1 Euglenophyta, were documented. Among them, Chloromonas anuraeae (Korshikov) Gerloff et Ettl and Chlorangiopsis systilis...

Chromium is a highly toxic non-essential metal for microorganisms and plants. Due to its widespread industrial use, chromium (Cr) has become a serious pollutant in diverse environmental settings. The presence of Cr leads to the selection of algal populations able to tolerate high levels of Cr compounds. The diverse Cr-resistance mechanisms displaye...

To better understand Euglena gracilis gene expression under different stress conditions (Chromium, Streptomycin or darkness), we undertook a survey of the E. gracilis transcriptome by cDNA sequencing and microarray analysis. First, we constructed a non-normalized cDNA library from the E. gracilis UTEX strain and sequenced a total of 1000 cDNAs. Six...

The effect of hexavalent chromium on fatty acid composition was studied in two strains of Euglena gracilis; UTEX 753 (from the Culture Collection of Algae of Texas University, USA) and MAT (isolated from a highly polluted River). Both were grown in photoauxotrophic and photoheterotrophic conditions and exposed to two metal concentrations, one below...

No abstract available.

The euglenoid genus Monomorphina was defined by Mereschowsky in 1877 to include rigid euglenoids that were pyriform in lateral view, had a hyaline spine at the posterior end, and one to few parietal chloroplasts typically without pyrenoids. The genus included taxa previously assigned to Phacus Dujardin or Euglena Ehrenberg. The general structure of...

Las Tablas de Daimiel National Park is a semiarid, hypertrophic wetland located in La Mancha (Ciudad Real, Central Spain). During the period 1996-2002 we carried out monthly samplings at three sites of Las Tablas. Thirty five taxa of Euglenophytes of the genera Astasia (1 taxon), Euglena (15), Lepocinclis (6), Phacus (9), and Trachelomonas (4) were...

In this work we describe on the basis of light and scanning electron microscopy a new species of the genus Trachelomonas (Euglenophyta), Trachelomonas iberaensis sp. nova, from Iberá System, Corrientes, Argentina.

SUMMARYA new strain of Euglena gracilis Klebs has been isolated from a highly polluted river; it was named MAT. Strain growth in different culture media was evaluated under heterotrophic and autotrophic conditions. Total lipid, sugar, protein and chlorophyll a production were studied. Results obtained for MAT were compared with data obtained for a...

A taxonomical study about the genus Strombomonas Deflandre from Yacarey stream (Corrientes, Argentina) was carried out. Samples were collected monthly between February 1996 and January 1997. A total of 29 taxa were recorded, among these, S. acuminata var. deflandreana Conr., S. spiralis (Playf.) Defl., S. subcurvata (Proschkina-Lawrenko) and S. ver...

Nine taxa of Strombomonas Deflandre (Euglenophyta) from the province of Chaco (Argen-tina) have been examined with scanning electron microscopy (SEM). Details of the lorica ultrastructure are described and illustrated, five of them for the first time with SEM: Strombomonas confortii Zalocar de Domitrovic, S. eurystoma (Stein) Popova, S. longicauda...

Studies of oxidative stress were conducted in 2 strains of Euglena gracilis (MAT and UTEX). The cultures were subjected to different concentrations of hexavalent chromium. The superoxide dismutase activity, the amount of total lipids and the concentration of clorophyll were determined and the respective growth curves were obtained. The results obta...

Studies of oxidative stress were conducted in 2 strains of Euglena gracilis (MAT and UTEX). The cultures were subjected to different concentrations of hexavalent chromium. The superoxide dismutase activity, the amount of total lipids and the concentration of clorophyll were determined and the respective growth curves were obtained. The results obta...

Small subunit rDNA sequences of 42 taxa belonging to 10 genera were used to infer phylogenetic relationships among euglenoids. Members of the phototrophic genera Euglena, Phacus, Lepocinclis, Colacium, Trachelomonas, and Strombomonas plus the osmotrophs Astasia longa, Khawkinea quartana, and Hyalophacus ocellatus were included. Six major clades wer...

The general fine structure of P. splendens Pochman (Section Pleurapsis) is described. This Section comprises a series of species with very distinctive features unshared by the majority of the members of the genus. The cells are pear-shaped in frontal view, rounded at the anterior end, narrowed posteriorly tapering in a long twisted tail. In lateral...

The Euglenophyta include four genera of Euglena-like cells enclosed in a lorica. Two of these genera, Trachelomonas and Strombomonas, are free swimming. These taxa have been differentiated and classified at the generic and species level based primarily on the morphology of their lorica. Numerous SEM studies have been conducted, yet few, if any, TEM...

Almost since the creation of the genus Euglena (Ehrenberg), the taxa assigned to it have been separated, split apart, and reorganized into new genera based on morphological relationships, resulting in the creation of the genera Phacus (Dujardin), Lepocinclis (Perty), Astasia (Pringsheim), and Khawkinea ( Jahn and McKibben) based on intuitive method...

Las Tablas de Daimiel is one of the most important wetlands in the Iberian Peninsula. The increase of water contamination is producing obvious eutrophication. Monthly water samples were taken during 1996 and 1997 at five places - both from channels and shallow water (tablas). 18 taxa of Euglenophyta were found, two of them had been found before in...

Las Tablas de Daimiel is one of the most important wetlands in the Iberian Península. The increase of water contamination is producing obvious eutrophication. Monthly water samples were taken during 1996 and 1997 at five places - both from channels and shallow water (tablas). 18 taxa of Euglenophyta were found, two of them had been found before in...

Euglena acus, Euglena spirogyra, Phacus curvicaudus, Phacus pyrum and Phacus tortus isolated from Matanza River, Buenos Aires, Argentina, were grown in soil-water medium. When transferred to soil-water medium enriched with different beef-extract concentrations, a marked cell deformation could be observed in every instance, owing either to an extrao...

The phytoplankton of the Matanza-Riachuelo river (Buenos Aires, Argentina) was studied for a period of 15 months together with different physical and chemical variables, along an increasingly eutrophic in character downstream. 281 taxa were recorded within a seasonal succession, among these 49 percent were euglenophyta, 25 percent bacillariophyta,...

79 taxons appartenant aux genres Trachelomonas Ehr. et Strombomonas Defl. (Euglenophyta) provenant de bras morts de rivières d'Alabama et d'Indiana, U.S.A., sont étudiés. Nous proposons 9 nouvelles espèces, 7 nouvelles variétés et 1 nouvelle forme. Treize taxons ont été examinés au microscope électronique à balayage

Dans le présent travail, 85 taxons de la classe des Euglenophyta, qui proviennent du lac Camaleao (île Marchantaria, près de Manaus au Brésil), sont étudiés, 20 appartenant au genre #Euglena$ Ehr., 18 au genre #Lepocinclis$ Perty et 47 au genre #Phacus$ Duj. Nous proposons 5 nouvelles espèces : #L. americana$, #L. claviformes$, #P. pygmaeus$, #P. r...

Dans le présent travail, 37 taxons appartenant au genre #Trachelomonas$ Ehr. (#Euglenophyta$) provenant d'Amazonie Colombienne sont étudiés au microscope électronique à balayage. Nous proposons une nouvelle espèce : #T. duquei$ et deux nouvelles formes : #T. armata$ var. #gordeievii$ fo. #minor$ et #T. armata$ var. #spinosa$ n. fo. (Résumé d'auteur...

Dans le présent travail, 90 taxons appartenant au genre #Trachelomonas$ Ehr. (Euglenophyta) provenant du lac Camaleao (île Marchantaria, près de Manaus au Brésil) sont étudiés. Nous proposons une nouvelle espèce : #T. amazonensis$, et 7 nouvelles variétés : #T. allorgei$ var. #sparsispina$, #T. amphoriformis$ var #spinosa$, #T. angustispina$ var. #...

Dans le présent travail, 43 taxons appartenant au genre #Strombomonas$ Defl. (#Euglenophyta$) provenant du lac Camaleao (île Marchantaria, près de Manaus au Brésil) sont étudiés. Nous proposons une nouvelle espèce : #S. brasiliensis$ et deux nouvelles variétés : #S. fluviatilis$ var. #major$ et #S. gibberosa$ var. #major$. Treize des taxons cités o...

Thèse. Doct. Sc. biologiques. Buenos Aires.