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Maggy N. B. Momba - One of the best experts on this subject based on the ideXlab platform.

  • Kinetics of petroleum oil biodegradation by a consortium of three protozoan isolates (Aspidisca sp., Trachelophyllum sp. and Peranema sp.)
    Biotechnology reports (Amsterdam Netherlands), 2017
    Co-Authors: L. Kachieng’a, Maggy N. B. Momba
    Abstract:

    Abstract Petroleum oil is a complex mixture of substances, the majority of which are hydrocarbons; the latter represent an extremely important and heterogeneous group of compounds that find their way into water resources by anthropogenic or natural ways. The majority of toxic hydrocarbon components of petroleum are biodegradable, where bioremediation using microbial species has become an integral process for the restoration of oil-polluted areas. In this study, three bioremediation processes, namely natural attenuation, nutrient supplementation by adding glucose and biostimulation by adding Tween ® 80, were carried out in various petroleum hydrocarbon concentrations in polluted water media using a consortium of three protozoan isolates ( Aspidisca sp., Trachelophyllum sp. and Peranema sp.). A first-order kinetics model was fitted to the biodegradation data to evaluate the biodegradation rate and to determine the corresponding half-life time. First-order kinetics satisfactorily described the biodegradation of the petroleum-based contaminants under abiotic conditions. The results showed an increase in the percentage removal of petroleum oil at the lower petroleum concentrations and a gradual percentage decrease in removing petroleum oil residues occurred when there was an increase in the initial concentrations of the petroleum oil: 39%, 27%, 22%, 12%, 10% for various petroleum oil concentrations of 50, 100, 150, 200, 250 mg/L, respectively. A similar trend was also observed in the glucose-supplemented culture media where the reduction was 45% and 78% for petroleum concentrations of 250 mg/L and 50 mg/L, respectively. Biodegradation of between 33 and 90% was achieved at a Tween ® 80 concentration of between 50 mg/L and 250 mg/L. The degradation rate constants for the natural attenuation process ranged between ≥0 to ≤0.50, ≥0 to ≤0.35, ≥0 to ≤0.25, ≥0 to ≤ 0.14 and ≥ 0 to ≤0.11 for petroleum oil concentrations varying from 50, 100, 150, 200 and 250 mg/L, respectively, during the study after 30 days. In the presence of glucose as a nutrient supplement, the degradation rate constants increased from 0 day −1 to 0.8 day −1 when exposed to the lowest oil concentration of 50 mg/L, while the lowest rate constants (from 0 day −1 to 0.25 day −1 ) were observed at the highest petroleum oil concentration of 250 mg/L for the same period. Overall enhancement of the degradation rates was achieved when adding the Tween ® 80 surfactant compared to the first two biodegradation processes. The longest half-life was achieved after 217 days during the natural attenuation process for samples with an oil concentration of 250 mg/L and this was reduced to 85 days using the glucose-supplemented process. There was a further decrease to 45 days when Tween ® 80 surfactant was added during the biostimulation process. The highest efficiency of ≥20% of Tween ® 80 was observed between 6 and 18 days and thereafter it decreased slightly to ≤20%.

  • The ability of consortium wastewater protozoan and bacterial species to remove COD in the presence of nanomaterials under varying pH conditions.
    Journal of environmental science and health. Part A Toxic hazardous substances & environmental engineering, 2017
    Co-Authors: Anza-vhudziki Mboyi, Ilunga Kamika, Maggy N. B. Momba
    Abstract:

    The aim of this study was to ascertain the survival limit and capability of commonly found wastewater protozoan (Aspidisca sp, Trachelophyllum sp and Peranema sp) and bacterial (Bacillus licheniformis, Brevibacillus laterosporus and Pseudomonas putida) species to remove COD while exposed to commercial nanomaterials under varying pH conditions. The experimental study was carried out in modified mixed liquor media adjusted to various pH levels (pH 2, 7 and 10) and a comparative study was performed to determine the difference between the cytotoxicity effects of commercial zinc oxide (nZnO) and silver (nAg) nanomaterials (NMs) on the target wastewater microbial communities using standard methods. The selected microbial communities were exposed to lethal concentrations ranging from 0.015 g/L to 40 g/L for nZnO and from 0.015 g/L to 2 g/L for nAg for a period of 5 days of incubation at 30°C (100 r/min). Compared with the absence of NMs in wastewater mixed liquor, the relevant environmental concentration ranging between 10 µg/L and 100 µg/L, for both nZnO and nAg caused no adverse effects, but the presence of 20 g of nZnO/L and 0.65 g of nAg/L significantly inhibited microbial growth. Statistical evidence showed that nAg was significantly more toxic compared to nZnO, but there was an insignificant difference in toxicity between microbial communities and pH variations. A significant decrease in the removal of COD by microbial populations was observed in the presence of NMs with a moderate correlation of r = 0.3 to r = 0.7 at all pH levels. It was evident that there was a physical interaction between commercial NMs and target wastewater microbial communities; although not quantitatively assessed, cell morphology and cell death were observed. Such phenomena suggest the high resilience of the microbial community, but it is the accumulation of NMs that will have adverse effects on the performance in terms of COD removal.

  • Biodegradation of petroleum hydrocarbon functional groups in contaminated water using selected protozoan isolates
    Journal of Environmental Chemical Engineering, 2017
    Co-Authors: L. Kachieng’a, Maggy N. B. Momba
    Abstract:

    Abstract Diverse microorganisms are responsible for the biodegradation of various petroleum hydrocarbon chains which are found in both the environment and several existing water sources. Most of these microorganisms are both prokaryotic and eukaryotic in nature. The aim of this study was to investigate the degradation of petroleum hydrocarbon functional groups in contaminated water using individual protozoan species (Aspidisca sp., Trachelophyllum sp. and Peranema sp.) as well as a consortium of these three protozoan species. Chemical oxygen demand (COD) and dissolved oxygen (DO) were analysed using standard methods. The concentration of petroleum oil was determined in triplicate before and after the inoculation of oily wastewaters with the abovementioned protozoan species using the partition-gravimetric method. Various functional groups that had been biodegraded by the protozoan isolates were analysed using thin-layer chromatography (TLC) and GC × GC-FID. Results showed an increase in protozoan biomass from an initial cell count of 1.0 × 103 cells/mL to a final cell count of 2.4 × 103 cells/mL for the consortium of isolates, unlike a minimal biomass increases observed with individual isolates over the study period. The average uptake of DO was found to be low at 0.50 mg/L from an initial concentration of 6.46 mg/L to the final concentration of 6.00 mg/L; however, the concentration of COD released by the isolates was found to be in an average range of ≤2300 mg/L. The consortium of three isolates was able to biodegrade ≥80% of the hydrocarbon fractions, and aliphatic groups such as short-chain alkanes, alcohol/ester compounds and partially aromatic hydrocarbons were biodegraded, while the individual isolates were able to biodegrade an average of 72% of the amount of petroleum hydrocarbon fractions during the study.

  • Effect of nickel on nutrient removal by selected indigenous protozoan species in wastewater systems
    Saudi Journal of Biological Sciences, 2015
    Co-Authors: Ilunga Kamika, Maggy N. B. Momba
    Abstract:

    Nutrient and heavy metal pollutions are major concern worldwide. This study aimed at comparing the effect of Ni2+ on nutrient removal efficiency of four indigenous wastewater protozoan species (Aspidisca sp., Paramecium sp., Peranema sp., Trachelophyllum sp.). Specific physicochemical parameters and microbial growth/die-off were measured using standard methods. The results revealed that protozoan species were able to simultaneously remove phosphate, nitrate and Ni2+ at concentrations ranging between 66.4–99.36%, 56.19–99.88% and 45.98–85.69%, respectively. Peranema sp. appeared to be the isolates with the highest removal of nutrients (Phosphate-99.36% and Nitrate-99.88%) while Paramecium sp. showed higher removal of Ni2+ at 85.69% and low removal of nutrients. Aspidisca sp. was the most sensitive isolate to Ni2+ but with significant nutrient removal (Phosphate-66.4% and Nitrate-56.19%) at 10 mg-N2+/L followed by an inhibition of nutrient removal at Ni2+ concentration greater than 10 mg/L. Significant correlation between the growth rate and nutrient removal (r = 0.806/0.799, p 

  • Effect of vanadium toxicity at its different oxidation states on selected bacterial and protozoan isolates in wastewater systems
    Environmental Technology, 2014
    Co-Authors: Ilunga Kamika, Maggy N. B. Momba
    Abstract:

    This study assesses and compares vanadium toxicity in its different oxidation states towards bacterial isolates (Pseudomonas putida and Bacillus licheniformis) and protozoan isolates (Peranema sp. and Trachelophyllum sp.). The isolates were exposed to various concentrations of V in mixed liquors and their tolerance to V was assessed at 30°C at a pH of 4. The results revealed that the increase in V oxidation state increased its toxicity to bacterial isolates, whereas its toxicity decreased for protozoan isolates. Among the bacterial isolates, P. putida was found to be more tolerant to V3+(24 h-median lethal concentration (LC50): 390 mg/l), V4+(24 h-LC50: 230–250 mg/l) and V5+(24 h-LC50: 180–200 mg/l), whereas for the protozoan isolates, Peranema sp. appeared to be more tolerant to V3+(24 h-LC50: 110–120 mg/l), V4+(24 h-LC50: 160–170 mg/l) and V5+(24 h-LC50: 160–200 mg/l). A comparison of both groups of organisms revealed Trachelophyllum sp. as the most sensitive organism to V at its various oxidation state...

Richard E Triemer - One of the best experts on this subject based on the ideXlab platform.

  • Character evolution in heterotrophic euglenids
    European Journal of Protistology, 2001
    Co-Authors: Brian S. Leander, Richard E Triemer, Mark A. Farmer
    Abstract:

    This article attempts to describe the key morphological innovations associated with the evolutionary transitions between bacteriotrophy, eukaryotrophy, phototrophy, and osmotrophy in euglenids. Attention was focused on heterotrophic euglenids in an effort to establish a robust phylogenetic hypothesis for the group as a whole. We present a cladistic analysis of a large morphological data set from the following taxa: Petalomonas, Entosiphon, Lentomonas, Ploeotia, Dinema, Distigma, Rhabdomonas, Menoidium, Peranema, Urceolus, Eutreptia, and Euglena. The majority of the 37 characters and 97 states recognized were associated with the pellicle, the feeding apparatus, and the flagellar apparatus. In addition to having pellicle strips, Petalomonas cantuscygni possessed mitochondrial inclusions that were strikingly similar to the kinetoplasts found in kinetoplastids. Dinema sulcatum held a pivotal position in the phylogenetic tree and possessed many characters that bridged bacteriotrophic taxa with eukaryotrophic taxa. Distigmids and rhabdomonads formed a clade of osmotrophs that descended from eukaryotrophic ancestors, while Urceolus cyclostomus possessed a feeding apparatus, a putative photoreception apparatus and cytoskeletal features that clearly linked the phototrophs to eukaryotrophic ancestors. Evolutionary implications that emerged from these results were discussed.

  • PHYLOGENETIC RELATIONSHIPS OF SELECTED EUGLENOID GENERA BASED ON MORPHOLOGICAL AND MOLECULAR DATA
    Journal of Phycology, 1997
    Co-Authors: Ann E. Montegut-felkner, Richard E Triemer
    Abstract:

    The small subunit rRNA (SSU rRNA) coding regions sequenced from the euglenoids Petalomonas cantuscygni, Peranema trichophorum, and Khawkinea quartana were used to assess the phylogenetic relationships of these genera within the Euglenozoa. Phylogenies derived from distance, parsimony, and maximum likelihood methods infer that the euglenoids and kinetoplastids form sister clades within a monophyletic assemblage. Distances representative of closely related lineages separate the genera within the Kinetoplastida, whereas larger distance values separate genera within the euglenoid assemblage. The results of the morphological and molecular studies suggest that phagotrophy arose early in the euglenozoan lineage with the subsequent acquisition of phototrophy, osmotrophy, and parasitism. Phagotrophic euglenoids with a pellicle composed of longitudinal strips appear to have diverged prior to genera with helically arranged strips. This study suggests that the hypothetical ancestor to the Euglenozoa was a phagotroph with two flagella, both containing paraxonemal rods. Furthermore, its basal bodies contained proximal cartwheels, were connected by a prominent fiber, and were anchored with three asymmetrically arranged flagellar roots.

  • PHYLOGENETIC RELATIONSHIPS OF SELECTED EUGLENOID GENERA BASED ON MORPHOLOGICAL AND MOLECULAR DATA
    Journal of Phycology, 1997
    Co-Authors: Ann E. Montegut-felkner, Richard E Triemer
    Abstract:

    The small subunit rRNA (SSU rRNA) coding regions sequenced from the euglenoids Petalomonas cantuscygni, Peranema trichophorum, and Khawkinea quartana were used to assess the phylogenetic relationships of these genera within the Euglenozoa. Phylogenies derived from distance, parsimony, and maximum likelihood methods infer that the euglenoids and kinetoplastids form sister clades within a monophyletic assemblage. Distances representative of closely related lineages separate the genera within the Kinetoplastida, whereas larger distance values separate genera within the euglenoid assemblage. The results of the morphological and molecular studies suggest that phagotrophy arose early in the euglenozoan lineage with the subsequent acquisition of phototrophy, osmotrophy, and parasitism. Phagotrophic euglenoids with a pellicle composed of longitudinal strips appear to have diverged prior to genera with helically arranged strips. This study suggests that the hypothetical ancestor to the Euglenozoa was a phagotroph with two flagella, both containing paraxonemal rods. Furthermore, its basal bodies contained proximal cartwheels, were connected by a prominent fiber, and were anchored with three asymmetrically arranged flagellar roots.

  • FEEDING IN Peranema TRICHOPHORUM REVISITED (EUGLENOPHYTA)1
    Journal of Phycology, 1997
    Co-Authors: Richard E Triemer
    Abstract:

    Feeding in Peranema trichophorum (Ehrenberg 1838) Stein 1878 was first observed over a century ago, yet there is still contention over how the feeding apparatus is used in feeding. Using video microscopy and scanning microscopy, this study documents two types of feeding. Peranema may engulf prey cells whole. Immotile cells are preferred, but moving cells occasionally are engulfed. Details of the early stages of engulfment are presented using scanning electron microscopy. A second method of feeding begins with the attachment of Peranema to a prey cell. The rods of the feeding apparatus then are repeatedly scraped over the surface of the prey until a tear occurs in the cell. The feeding apparatus is inserted into the opening and the internal cell contents are sucked out. The anterior flagellum is inserted into the prey to help remove the cell's contents.

Ilunga Kamika - One of the best experts on this subject based on the ideXlab platform.

  • The ability of consortium wastewater protozoan and bacterial species to remove COD in the presence of nanomaterials under varying pH conditions.
    Journal of environmental science and health. Part A Toxic hazardous substances & environmental engineering, 2017
    Co-Authors: Anza-vhudziki Mboyi, Ilunga Kamika, Maggy N. B. Momba
    Abstract:

    The aim of this study was to ascertain the survival limit and capability of commonly found wastewater protozoan (Aspidisca sp, Trachelophyllum sp and Peranema sp) and bacterial (Bacillus licheniformis, Brevibacillus laterosporus and Pseudomonas putida) species to remove COD while exposed to commercial nanomaterials under varying pH conditions. The experimental study was carried out in modified mixed liquor media adjusted to various pH levels (pH 2, 7 and 10) and a comparative study was performed to determine the difference between the cytotoxicity effects of commercial zinc oxide (nZnO) and silver (nAg) nanomaterials (NMs) on the target wastewater microbial communities using standard methods. The selected microbial communities were exposed to lethal concentrations ranging from 0.015 g/L to 40 g/L for nZnO and from 0.015 g/L to 2 g/L for nAg for a period of 5 days of incubation at 30°C (100 r/min). Compared with the absence of NMs in wastewater mixed liquor, the relevant environmental concentration ranging between 10 µg/L and 100 µg/L, for both nZnO and nAg caused no adverse effects, but the presence of 20 g of nZnO/L and 0.65 g of nAg/L significantly inhibited microbial growth. Statistical evidence showed that nAg was significantly more toxic compared to nZnO, but there was an insignificant difference in toxicity between microbial communities and pH variations. A significant decrease in the removal of COD by microbial populations was observed in the presence of NMs with a moderate correlation of r = 0.3 to r = 0.7 at all pH levels. It was evident that there was a physical interaction between commercial NMs and target wastewater microbial communities; although not quantitatively assessed, cell morphology and cell death were observed. Such phenomena suggest the high resilience of the microbial community, but it is the accumulation of NMs that will have adverse effects on the performance in terms of COD removal.

  • Effect of nickel on nutrient removal by selected indigenous protozoan species in wastewater systems
    Saudi Journal of Biological Sciences, 2015
    Co-Authors: Ilunga Kamika, Maggy N. B. Momba
    Abstract:

    Nutrient and heavy metal pollutions are major concern worldwide. This study aimed at comparing the effect of Ni2+ on nutrient removal efficiency of four indigenous wastewater protozoan species (Aspidisca sp., Paramecium sp., Peranema sp., Trachelophyllum sp.). Specific physicochemical parameters and microbial growth/die-off were measured using standard methods. The results revealed that protozoan species were able to simultaneously remove phosphate, nitrate and Ni2+ at concentrations ranging between 66.4–99.36%, 56.19–99.88% and 45.98–85.69%, respectively. Peranema sp. appeared to be the isolates with the highest removal of nutrients (Phosphate-99.36% and Nitrate-99.88%) while Paramecium sp. showed higher removal of Ni2+ at 85.69% and low removal of nutrients. Aspidisca sp. was the most sensitive isolate to Ni2+ but with significant nutrient removal (Phosphate-66.4% and Nitrate-56.19%) at 10 mg-N2+/L followed by an inhibition of nutrient removal at Ni2+ concentration greater than 10 mg/L. Significant correlation between the growth rate and nutrient removal (r = 0.806/0.799, p 

  • Effect of vanadium toxicity at its different oxidation states on selected bacterial and protozoan isolates in wastewater systems
    Environmental Technology, 2014
    Co-Authors: Ilunga Kamika, Maggy N. B. Momba
    Abstract:

    This study assesses and compares vanadium toxicity in its different oxidation states towards bacterial isolates (Pseudomonas putida and Bacillus licheniformis) and protozoan isolates (Peranema sp. and Trachelophyllum sp.). The isolates were exposed to various concentrations of V in mixed liquors and their tolerance to V was assessed at 30°C at a pH of 4. The results revealed that the increase in V oxidation state increased its toxicity to bacterial isolates, whereas its toxicity decreased for protozoan isolates. Among the bacterial isolates, P. putida was found to be more tolerant to V3+(24 h-median lethal concentration (LC50): 390 mg/l), V4+(24 h-LC50: 230–250 mg/l) and V5+(24 h-LC50: 180–200 mg/l), whereas for the protozoan isolates, Peranema sp. appeared to be more tolerant to V3+(24 h-LC50: 110–120 mg/l), V4+(24 h-LC50: 160–170 mg/l) and V5+(24 h-LC50: 160–200 mg/l). A comparison of both groups of organisms revealed Trachelophyllum sp. as the most sensitive organism to V at its various oxidation state...

  • Effect of vanadium toxicity at its different oxidation states on selected bacterial and protozoan isolates in wastewater systems.
    Environmental technology, 2014
    Co-Authors: Ilunga Kamika, Maggy N. B. Momba
    Abstract:

    This study assesses and compares vanadium toxicity in its different oxidation states towards bacterial isolates (Pseudomonas putida and Bacillus licheniformis) and protozoan isolates (Peranema sp. and Trachelophyllum sp.). The isolates were exposed to various concentrations of V in mixed liquors and their tolerance to V was assessed at 30 degrees C at a pH of 4. The results revealed that the increase in V oxidation state increased its toxicity to bacterial isolates, whereas its toxicity decreased for protozoan isolates. Among the bacterial isolates, P putida was found to be more tolerant to V3+(24h-median lethal concentration (LC50): 390mg/l), V4+(24h-LC50: 230-250mg/l) and V5+(24h-LC50: 180-200mg/l), whereas for the protozoan isolates, Peranema sp. appeared to be more tolerant to V3+(24 h-LC50: 110-120 mg/l), V4+(24 h-LC50: 160-170 mg/l) and V5+(24 h-LC50: 160-200 mg/l). A comparison of both groups of organisms revealed Trachelophyllum sp. as the most sensitive organism to V at its various oxidation states. The visual and spectrophotometric methods used to assess V reduction revealed that P. putida was the only isolate able to reduce V5+, V4+ and V3+ to V2+ in mixed liquor media. Vanadium (+2) in concentrations of approximately 46.46 mg/l, 29.57 m mg/l and 38.01 mg/l found in the media was treated with V3+, V4+ and V5+, respectively, and inoculated with P. putida. This study revealed that the ability of V reduction, adopted with P putida, can be an effective strategy to remove V from polluted environments. This study also showed that the toxicity of V, in terms of its oxidation states, differs from one species to another and in kingdoms.

  • Assessing the resistance and bioremediation ability of selected bacterial and protozoan species to heavy metals in metal-rich industrial wastewater
    BMC Microbiology, 2013
    Co-Authors: Ilunga Kamika, Maggy N. B. Momba
    Abstract:

    Background Heavy-metals exert considerable stress on the environment worldwide. This study assessed the resistance to and bioremediation of heavy-metals by selected protozoan and bacterial species in highly polluted industrial-wastewater. Specific variables (i.e. chemical oxygen demand, pH, dissolved oxygen) and the growth/die-off-rates of test organisms were measured using standard methods. Heavy-metal removals were determined in biomass and supernatant by the Inductively Couple Plasma Optical Emission Spectrometer. A parallel experiment was performed with dead microbial cells to assess the biosorption ability of test isolates. Results The results revealed that the industrial-wastewater samples were highly polluted with heavy-metal concentrations exceeding by far the maximum limits (in mg/l) of 0.05-Co, 0.2-Ni, 0.1-Mn, 0.1-V, 0.01-Pb, 0.01-Cu, 0.1-Zn and 0.005-Cd, prescribed by the UN-FAO. Industrial-wastewater had no major effects on Pseudomonas putida , Bacillus licheniformis and Peranema sp. (growth rates up to 1.81, 1.45 and 1.43 d^-1, respectively) compared to other test isolates. This was also revealed with significant COD increases (p 

Patricia L. Walne - One of the best experts on this subject based on the ideXlab platform.

  • ultrastructure of the flagella of the colorless phagotroph Peranema trichophorum euglenophyceae i flagellar mastigonemes1
    Journal of Phycology, 2004
    Co-Authors: Lula L Hilenski, Patricia L. Walne
    Abstract:

    Peranema trichophorum (Ehrenberg) Stein, a colorless phagotrophic euglenoid flagellate, has a typically euglenoid microtubular root complement. Striated root components, relatively uncommon in euglenoids, are connected to the basal bodies and to a microtubular root. The flagellar system of Peranema consists of three unequal microtubular roots which extend anteriorly beneath the reservoir membrane, and narrow-band striated roots (periodicity = 29–33 nm) which connect one of the four basal bodies to the movable rodorgan of the feeding apparatus. An inter basal body striated fiber forms a three-way connection between one particular microtubular root, a flagellar basal body, and the striated roots. A striated fibril (periodicity = 18–25 nm), which may be an extension of the striated root system, extends beneath the reservoir membrane. Associated with the striated fibril and the striated roots are cisternae of smooth endoplasmic reticulum.

  • ultrastructure of the flagella of the colorless phagotroph Peranema trichophorum euglenophyceae i flagellar mastigonemes1
    Journal of Phycology, 2004
    Co-Authors: Lula L Hilenski, Patricia L. Walne
    Abstract:

    Peranema trichophorum (Ehrenberg) Stein, a colorless phagotrophic euglenoid flagellate, has a typically euglenoid microtubular root complement. Striated root components, relatively uncommon in euglenoids, are connected to the basal bodies and to a microtubular root. The flagellar system of Peranema consists of three unequal microtubular roots which extend anteriorly beneath the reservoir membrane, and narrow-band striated roots (periodicity = 29–33 nm) which connect one of the four basal bodies to the movable rodorgan of the feeding apparatus. An inter basal body striated fiber forms a three-way connection between one particular microtubular root, a flagellar basal body, and the striated roots. A striated fibril (periodicity = 18–25 nm), which may be an extension of the striated root system, extends beneath the reservoir membrane. Associated with the striated fibril and the striated roots are cisternae of smooth endoplasmic reticulum.

Angelika Preisfeld - One of the best experts on this subject based on the ideXlab platform.

  • Ultrastructural and immunocytochemical investigation of paramylon combined with new 18S rDNA-based secondary structure analysis clarifies phylogenetic affiliation of Entosiphon sulcatum (Euglenida: Euglenozoa)
    Organisms Diversity & Evolution, 2017
    Co-Authors: Stefan Paerschke, Almut H. Vollmer, Angelika Preisfeld
    Abstract:

    The phylogeny of phagotrophic euglenids is widely based on nuclear small subunit ribosomal DNA (18S rDNA) sequence data, but most analyses suffer from weakness in statistical support regarding the “connecting backbone” between monophyletic clades. Moreover, the position of Entosiphon has remained unclear. Testing the 18S rDNA capability for a phylogeny of phagotrophic euglenids, we isolated sequences of Peranema sp. and Ploeotia edaphica and utilized secondary structure data as a prerequisite for recognition of homologous positions. We found a unique, clade-specific nucleotide substitution in the deduced 18S rDNA helix 44. Since our 18S rDNA phylogenies could only in part resolve positions of phagotrophic lineages, but did not verify that of Entosiphon , we investigated the phagotrophic key taxa Peranema trichophorum , Petalomonas cantuscygni , Ploeotia costata , and Entosiphon sulcatum ultrastructurally. Additionally, we explored the presence or absence of the euglenid reserve carbohydrate paramylon by specific staining with monoclonal anti-β-1,3-glucan antibodies. Paramylon was found to be clearly present in P. trichophorum and E. sulcatum , but was absent in Pt. cantuscygni and Pl. costata . Combined results of our molecular, ultrastructural, and immunocytochemical investigations suggest that Entosiphon sulcatum is the sister taxon of a monophyletic euglenid crown clade, characterized by a helical pellicle, which we propose to rename. This phylogenetic affiliation is confirmed by a clade-specific primary absence of the unique nucleotide substitution in helix 44 and by the common presence of paramylon.

  • Phylogenetic position and inter-relationships of the osmotrophic euglenids based on SSU rDNA data, with emphasis on the Rhabdomonadales (Euglenozoa).
    International journal of systematic and evolutionary microbiology, 2001
    Co-Authors: Angelika Preisfeld, I Busse, M Klingberg, S Talke, H G Ruppel
    Abstract:

    In order to reconstruct the evolution of euglenid flagellates, euglenozoan SSU rDNA data have been used to investigate phylogenetic relationships with a focus on osmotrophic taxa and especially on the Rhabdomonadales. The dataset consisting of the SSU rDNAs of osmotrophic, phagotrophic and phototrophic taxa was used in parsimony, maximum-likelihood and distance analyses. Five genera make up the Rhabdomonadales, all of them osmotrophic: Gyropaigne, Menoidium, Parmidium, Rhabdomonas and Rhabdospira. According to our analyses they form a strongly supported monophyletic assemblage which is characterized by a low sequence divergence compared to the euglenids in general. Closest relatives are the members of the osmotrophic genus Distigma. All primary osmotrophic species constitute a larger monophyletic group with the phototrophic euglenids and the phagotroph Peranema trichophorum. The combination of three rhabdomonadalian species Rhabdomonas gibba, Rhabdomonas spiralis and Rhabdospira spiralis with nearly identical SSU rDNA sequences is strongly recommended. The phagotroph Petalomonas cantuscygni branches at the bottom of the euglenid subtree with significantly weaker support. The inter-relationship of the three distinct euglenozoan taxa (euglenids, kinetoplastids and diplonemids) could not be convincingly resolved by this study.

  • Phylogenetic analyses of various euglenoid taxa (Euglenozoa) based on 18S rDNA sequence data
    Journal of Phycology, 2000
    Co-Authors: Angelika Preisfeld, Silke Berger, Ingo Busse, Susanne Liller, Hans Georg Ruppel
    Abstract:

    18S rRNA genes (SSU rDNA) of five newly sequenced species were used as molecular markers to infer phylogenetic relationships within the euglenoids. Two members of the order Euglenales (Lepocinclis ovata Playfair, Phacus similis Christen), two of the order Eutreptiales (Distigma proteus Ehrenberg,, D. curvata Pringsheim) and Gyropaigne lefevrei Bourelly et Georges of the order Rhabdomonadales were used in parsimony, maximum likelihood, and distance analyses. All trees derived from SSU rRNA data strongly supported the monophyletic origin of the Euglenozoa, with kinetoplastids as sister clade to the euglenoids and Petalomonas cantuscygni Cann et Pennick diverging at the base of the monophyletic euglenoid lineage. The data also supported the theory that phagotrophic euglenoids arose prior to osmotrophs and phototrophs. A lineage of Peranema trichophorum Ehrenberg and all sequenced Euglenales formed a sister clade to the osmotrophs. This suggests that the evolution of phototrophy within the euglenoids radiated from a single event.