Thalassiosira weissflogii attachment assay and phylogenetic affiliation of bacterial isolates from samples of the German Wadden Sea

Aggregation of algae, mainly diatoms, is an important process in marine systems leading to the settling of particulate organic carbon predominantly in the form of marine snow. Exudation products of phytoplankton form transparent exopolymer particles (TEP), which acts as the glue for particle aggregation. Heterotrophic bacteria interacting with phytoplankton may influence TEP formation and phytoplankton aggregation. This bacterial impact has not been explored in detail. We hypothesized that bacteria attaching to Thalassiosira weissflogii might interact in a yet-to-be determined manner, which could impact TEP formation and aggregate abundance. The role of individual T. weissflogii-attaching and free-living new bacterial isolates for TEP production and diatom aggregation was investigated in vitro. T. weissflogii did not aggregate in axenic culture, and striking differences in aggregation dynamics and TEP abundance were observed when diatom cultures were inoculated with either diatom-attaching or free-living bacteria. The data indicated that free-living bacteria might not influence aggregation whereas bacteria attaching to diatom cells may increase aggregate formation. Interestingly, photosynthetically inactivated T. weissflogii cells did not aggregate regardless of the presence of bacteria. Comparison of aggregate formation, TEP production, aggregate sinking velocity and solid hydrated density revealed remarkable differences. Both, photosynthetically active T. weissflogii and specific diatom-attaching bacteria were required for aggregation. It was concluded that interactions between heterotrophic bacteria and diatoms increased aggregate formation and particle sinking and thus may enhance the efficiency of the biological pump.

Geochemistry, fatty acid content and phylogenetic affiliation of soil samples from Livingston Island, South Shetland Archipelago, Antarctica

Microorganisms inhabit very different soil habitats in the ice-free areas of Antarctica, playing a major role in nutrient cycling in cold environments. We studied the soil characteristics and the dominant bacterial composition from nine different soil profiles located on Livingston Island (maritime Antarctica). The total carbon (TC) and total nitrogen (TN) values were high for the vegetated soils, decreasing with depth, whereas the values for the mineral soils were generally low. Soil pH was more acidic for moss-covered soils and neutral to alkaline for mineral soils. Numbers of culturable heterotrophic bacteria were higher at vegetated sites, but significant numbers were also detectable in carbon-depleted soils. Patterns of denaturing gradient gel electrophoresis (DGGE) revealed a highly heterogeneous picture throughout the soil profiles. Subsequent sequencing of DGGE bands revealed in total 252 sequences that could be assigned to 114 operational taxonomic units, showing the dominance of members of the Bacteroidetes and Acidobacteria. The results of phospholipid fatty acid analysis showed a lack of unsaturated fatty acids for most of the samples. Samples with a prevalence of unsaturated over saturated fatty acids were restricted to several surface samples. Statistical analysis showed that the dominant soil bacterial community composition is most affected by TC and TN contents and soil physical factors such as grain size and moisture, but not pH. Keywords

Phylogenetic Analysis Of The Microbial Community In Hypersaline Petroleum Produced Water From The Campos Basin.

In this work the archaea and eubacteria community of a hypersaline produced water from the Campos Basin that had been transported and discharged to an onshore storage facility was evaluated by 16S recombinant RNA (rRNA) gene sequence analysis. The produced water had a hypersaline salt content of 10 (w/v), had a carbon oxygen demand (COD) of 4,300 mg/l and contains phenol and other aromatic compounds. The high salt and COD content and the presence of toxic phenolic compounds present a problem for conventional discharge to open seawater. In previous studies, we demonstrated that the COD and phenolic content could be largely removed under aerobic conditions, without dilution, by either addition of phenol degrading Haloarchaea or the addition of nutrients alone. In this study our goal was to characterize the microbial community to gain further insight into the persistence of reservoir community members in the produced water and the potential for bioremediation of COD and toxic contaminants. Members of the archaea community were consistent with previously identified communities from mesothermic reservoirs. All identified archaea were located within the phylum Euryarchaeota, with 98 % being identified as methanogens while 2 % could not be affiliated with any known genus. Of the identified archaea, 37 % were identified as members of the strictly carbon-dioxide-reducing genus Methanoplanus and 59 % as members of the acetoclastic genus Methanosaeta. No Haloarchaea were detected, consistent with the need to add these organisms for COD and aromatic removal. Marinobacter and Halomonas dominated the eubacterial community. The presence of these genera is consistent with the ability to stimulate COD and aromatic removal with nutrient addition. In addition, anaerobic members of the phyla Thermotogae, Firmicutes, and unclassified eubacteria were identified and may represent reservoir organisms associated with the conversion hydrocarbons to methane.

Phylogenetic And Phylogeographic Mapping Of The Avian Coronavirus Spike Protein-encoding Gene In Wild And Synanthropic Birds.

The evolution and population dynamics of avian coronaviruses (AvCoVs) remain underexplored. In the present study, in-depth phylogenetic and Bayesian phylogeographic studies were conducted to investigate the evolutionary dynamics of AvCoVs detected in wild and synanthropic birds. A total of 500 samples, including tracheal and cloacal swabs collected from 312 wild birds belonging to 42 species, were analysed using molecular assays. A total of 65 samples (13%) from 22 bird species were positive for AvCoV. Molecular evolution analyses revealed that the sequences from samples collected in Brazil did not cluster with any of the AvCoV S1 gene sequences deposited in the GenBank database. Bayesian framework analysis estimated an AvCoV strain from Sweden (1999) as the most recent common ancestor of the AvCoVs detected in this study. Furthermore, the analysis inferred an increase in the AvCoV dynamic demographic population in different wild and synanthropic bird species, suggesting that birds may be potential new hosts responsible for spreading this virus.

The Role Of Edaphic Environment And Climate In Structuring Phylogenetic Pattern In Seasonally Dry Tropical Plant Communities.

Seasonally dry tropical plant formations (SDTF) are likely to exhibit phylogenetic clustering owing to niche conservatism driven by a strong environmental filter (water stress), but heterogeneous edaphic environments and life histories may result in heterogeneity in degree of phylogenetic clustering. We investigated phylogenetic patterns across ecological gradients related to water availability (edaphic environment and climate) in the Caatinga, a SDTF in Brazil. Caatinga is characterized by semiarid climate and three distinct edaphic environments - sedimentary, crystalline, and inselberg -representing a decreasing gradient in soil water availability. We used two measures of phylogenetic diversity: Net Relatedness Index based on the entire phylogeny among species present in a site, reflecting long-term diversification; and Nearest Taxon Index based on the tips of the phylogeny, reflecting more recent diversification. We also evaluated woody species in contrast to herbaceous species. The main climatic variable influencing phylogenetic pattern was precipitation in the driest quarter, particularly for herbaceous species, suggesting that environmental filtering related to minimal periods of precipitation is an important driver of Caatinga biodiversity, as one might expect for a SDTF. Woody species tended to show phylogenetic clustering whereas herbaceous species tended towards phylogenetic overdispersion. We also found phylogenetic clustering in two edaphic environments (sedimentary and crystalline) in contrast to phylogenetic overdispersion in the third (inselberg). We conclude that while niche conservatism is evident in phylogenetic clustering in the Caatinga, this is not a universal pattern likely due to heterogeneity in the degree of realized environmental filtering across edaphic environments. Thus, SDTF, in spite of a strong shared environmental filter, are potentially heterogeneous in phylogenetic structuring. Our results support the need for scientifically informed conservation strategies in the Caatinga and other SDTF regions that have not previously been prioritized for conservation in order to take into account this heterogeneity.

Phylogenetic analyses of Cladophora vagabunda (L.) C. Hoek (Cladophorales, Chlorophyta) from Brazil based on SSU rDNA sequences

The complete SSU rDNA was sequenced for 10 individuals of Cladophora vagabunda collected along the coast of Brazil. For C. rupestris (L.) Kütz. a partial SSU rDNA sequence (1634 bp) was obtained. Phylogenetic trees indicate that Cladophora is paraphyletic, but the section Glomeratae sensu lato including C. vagabunda from Brazil, Japan and France, C. albida (Nees) Kütz., C. sericea (Hudson) Kütz., and C. glomerata (L.) Kütz. is monophyletic. Within this group C. vagabunda is paraphyletic. The sequence identity for the SSU rDNA varied from 98.9% to 100% for the Brazilian C. vagabunda, and from 98.3% to 99.7% comparing the Brazilian individuals to the ones from France and Japan. Sequence identity of the Brazilian C. vagabunda to C. albida and C. sericea vary from 98.0% to 98.6%. The SSU rDNA phylogeny support partially the morphological characteristics presented by Brazilian populations of C. vagabunda. On the other hand, C. rupestris from Brazil does not group with C. rupestris from France, both sequences presenting only 96.9% of identity. The inclusion of sequences of individuals from Brazil reinforces the need of taxonomical revision for the genus Cladophora and for the complex C. vagabunda.

A phylogenetic analysis of Brycon and Henochilus (Characiformes, Characidae, Bryconinae) based on the mitochondrial gene 16S rRNA

The genus Brycon, the largest subunit of the Bryconinae, has 42 valid species distributed from southern Mexico to the La Plata River in Argentina. Henochilus is a monotypic genus, comprising a single species (H. wheatlandii) found in the upper Rio Doce basin. In the present study, partial sequences of the mitochondrial gene 16S were obtained for fifteen species of Brycon and for Henochilus wheatlandii. The results showed that the genus Brycon is paraphyletic, since Henochilus is the sister-group of B. ferox and B. insignis. The most basal species analyzed were the trans-Andean species B. henni, B. petrosus, and B. chagrensis.

A new species of sand-dwelling catfish, with a phylogenetic diagnosis of Pygidianops Myers (Siluriformes: Trichomycteridae: Glanapteryginae)

A new species of sand-dwelling catfish genus Pygidianops, P. amphioxus, is described from the Negro and lower Amazon basins. The new species differs from its three congeners in the elongate eel-like body, the short barbels, and the small caudal fin, continuous with the body, among other traits of internal anatomy. The absence of anal fin further distinguishes P. amphioxus from all other Pygidianops species except P. magoi and the presence of eyes from all except P. cuao. The new Pygidianops seems to be the sister species to P. magoi, the two species sharing a unique mesethmoid with a dorsally-bent tip lacking cornua, and a produced articular process in the palatine for the articulation with the neurocranium. Pygidianops amphioxus is a permanent and highly-specialized inhabitant of psammic environments. Additional characters are proposed as synapomorphies of Pygidianops, including a hypertrophied symphyseal joint and associated ligament in the lower jaw; an elongate, laterally-directed, process on the dorsal surface of the premaxilla; and a rotated lower jaw, where the surface normally facing laterally in other glanapterygines is instead directed ventrally. These and other characters are incorporated into a revised phylogenetic diagnosis of Pygidianops.

A phylogenetic study of the subtribe Dicrepidiina (Elateridae, Elaterinae, Ampedini)

It is presented a cladistic analysis of the Dicrepidiina aiming to test the monophyletism of the subtribe and to establish the relationships among the genera. The subtribe is composed by 36 genera and all of them, except Asebis, Lamononia, Neopsephus, Semiotopsis and Spilomorphus were included in the analysis. Fifty two species, especially the type-species of each genus were studied: Achrestus flavocinctus (Candèze, 1859), A. venustus Champion, 1895, Adiaphorus gracilis Schwarz, 1901, A. ponticerianus Candèze, 1859, Anoplischiopsis bivittatus Champion, 1895, Anoplischius bicarinatus Candèze, 1859, A. conicus Candèze, 1900, A. haematopus Candèze, 1859, A. pyronotus Candèze, 1859, Atractosomus flavescens (Germar, 1839), Blauta cribraria (Germar, 1844), Calopsephus apicalis (Schwarz, 1903), Catalamprus angustus (Fleutiaux, 1902), Crepidius flabellifer (Erichson, 1847), C. resectus Candèze, 1859, Cyathodera auripilosus Costa, 1968, C. lanugicollis (Candèze, 1859), C. longicornis Blanchard, 1843, Dayakus angularis Candèze, 1893, Dicrepidius ramicornis (Palisot de Beauvois, 1805), Dipropus brasilianus (Germar, 1824), D. factuellus Candèze, 1859, D. laticollis (Eschscholtz, 1829), D. pinguis (Candèze, 1859), D. schwarzi (Becker, 1961), Elius birmanicus Candèze, 1893, E. dilatatus Candèze, 1878, Heterocrepidius gilvellus Candèze, 1859, H. ventralis Guérin-Méneville, 1838, Lampropsephus cyaneus (Candèze, 1878), Loboederus appendiculatus (Perty, 1830), Olophoeus gibbus Candèze, 1859, Ovipalpus pubescens Solier, 1851, Pantolamprus ligneus Candèze, 1896, P. mirabilis Candèze, 1896, P. perpulcher Westwood, 1842, Paraloboderus glaber Golbach, 1990, Proloboderus crassipes Fleutiaux, 1912, Propsephus beniensis (Candèze, 1859), P. cavifrons (Erichson, 1843), Pseudolophoeus guineensis (Candèze, 1881), Rhinopsephus apicalis (Schwarz, 1903), Sephilus formosanus Schwarz, 1912, S. frontalis Candèze, 1878, Singhalenus gibbus Candèze, 1892, S. taprobanicus Candèze, 1859, Sphenomerus antennalis Candèze, 1859, S. brunneus Candèze, 1865, Spilus atractomorphus Candèze, 1859, S. nitidus Candèze, 1859, Stenocrepidius simonii Fleutiaux, 1891 and Trielasmus varians Blanchard, 1846. Chalcolepidius zonatus (Hemirhipini, Agrypninae), Ctenicera silvatica (Prosternini, Prosterninae), and species of the other subtribes of Ampedini (Elaterinae): Ampedus sanguineus (Ampedina), Melanotus spernendus (Melanotina) and Anchastus digittatus and Physorhinus xanthocephalus (Physorhinina) were used as outgroups. The results of the phylogenetic analysis demonstrated that Dicrepidiina, as formerly defined, does not form a monophyletic group. One genus, represented by Ovipalpus pubescens, was removed from the subtribe. The subtribe is characterized by presence of lamella under 2nd and 3rd tarsomeres of all legs. Also, it was revealed that the genera Achrestus, Anoplischius, Dipropus and Propsephus are not monophyletic. Due to the scarcity of information, all the studied species are redescribed and illustrated.

Description and phylogenetic analysis of the Calycopidina (Lepidoptera, Lycaenidae, Theclinae, Eumaeini): a subtribe of detritivores

Description and phylogenetic analysis of the Calycopidina (Lepidoptera, Lycaenidae, Theclinae, Eumaeini): a subtribe of detritivores. The purpose of this paper is to establish a phylogenetic basis for a new Eumaeini subtribe that includes those lycaenid genera in which detritivory has been recorded. Morphological characters were coded for 82 species of the previously proposed "Lamprospilus Section" of the Eumaeini (19 of these had coding identical to another species), and a phylogenetic analysis was performed using the 63 distinct ingroup terminal taxa and six outgroups belonging to four genera. Taxonomic results include the description in the Eumaeini of Calycopidina Duarte & Robbins new subtribe (type genus Calycopis Scudder, 1876), which contains Lamprospilus Geyer, Badecla Duarte & Robbins new genus (type species Thecla badaca Hewitson), Arzecla Duarte & Robbins new genus (type species Thecla arza Hewitson), Arumecla Robbins & Duarte, Camissecla Robbins & Duarte, Electrostrymon Clench, Rubroserrata K. Johnson & Kroenlein revalidated status, Ziegleria K. Johnson, Kisutam K. Johnson & Kroenlein revalidated status, and Calycopis. Previous "infratribe" names Angulopina K. Johnson & Kroenlein, 1993, and Calycopina K. Johnson & Kroenlein, 1993, are nomenclaturally unavailable and polyphyletic as proposed. New combinations include Badecla badaca (Hewitson), Badecla picentia (Hewitson), Badecla quadramacula (Austin & K. Johnson), Badecla lanckena (Schaus), Badecla argentinensis (K. Johnson & Kroenlein), Badecla clarissa (Draudt), Arzecla arza (Hewitson), Arzecla tarpa (Godman & Salvin), Arzecla canacha (Hewitson), Arzecla calatia (Hewitson), Arzecla tucumanensis (K. Johnson & Kroenlein), Arzecla sethon (Godman & Salvin), Arzecla nubilum (H. H. Druce), Arzecla paralus (Godman & Salvin), Arzecla taminella (Schaus), Arzecla albolineata (Lathy), Electrostrymon denarius (Butler & H.Druce), Electrostrymon guzanta (Schaus), Electrostrymon perisus (H. H. Druce), Rubroserrata mathewi (Hewitson), Rubroserrata ecbatana (Hewitson), Kisutam micandriana (K. Johnson), and Kisutam syllis (Godman & Salvin). The structure of the male genitalia lateral window, labides, and brush organs are described and discussed, as are the female genitalia signa of the corpus bursae and 8th abdominal tergum. Widespread wing pattern sexual dimorphism in the Calycopidina is noted and illustrated, and the presence of alternating dark and light bands on the ventral wings of both sexes is discussed. The evidence for detritivory in Lamprospilus, Badecla, Arzecla, Arumecla, Camissecla, Electrostrymon, Ziegleria, Kisutam, and Calycopis is summarized using the new classification.