Search results for "bacteri"

Identification and biological traits of a planthopper from the genus Pentastiridius (Hemiptera: Cixiidae) adapted to an annual cropping rotation

2009

International audience; Cixiid planthoppers have been shown to vector phloem-limited prokaryotes associated with plant diseases world-wide. In eastern France, an emerging disease of sugar beet called syndrome basses richesses has been associated with phloem-restricted bacteria transmitted by a cixiid planthopper within the genus Pentastiridius. Early investigation suggested the species being Pentastiridius beieri. On the basis of a morphological and phylogenetic study we report the identification of the planthopper as Pentastiridius leporinus. Furthermore we report some biological traits of the species, which shows a surprising ecological adaptation to an annual cropping rotation sugar beet…

Chironomid incorporation of methane-derived carbon in plankton- and macrophyte-dominated habitats in a large shallow lake

2018

1. While 13 C-depleted carbon derived from biogenic methane can substantially contribute to the benthic secondary production in deep stratified lakes, its role in shallow lakes is less clear. We investigated the dynamics of δ13 C and δ15 N in the larvae of Chironomus plumosus throughout an annual cycle in two ecologically distinct basins (open-water plankton-dominated and sheltered macrophyte- covered) of a large (270 km2 ), shallow, polymictic and eutrophic lake (Võrtsjärv, Estonia, North Europe). The larval stable isotopic compositions were linked to the presence of methane-oxidising bacteria (MOB) in larval guts and sediments. 2. Molecular detection of MOB revealed their presence in vari…

Limnology and Aquatic Microbial Ecology of Byers Peninsula: A Main Freshwater Biodiversity Hotspot in Maritime Antarctica

2019

Here we present a comprehensive review of the diversity revealed by research in limnology and microbial ecology conducted in Byers Peninsula (Livingston Island, South Shetland Islands, Antarctica) during the last two decades. The site constitutes one of the largest ice-free areas within the Antarctic Peninsula region. Since it has a high level of environmental protection, it is less human-impacted compared to other sites within the South Shetland archipelago. The main investigations in Byers Peninsula focused on the physical and chemical limnology of the lakes, ponds, rivers, and wetlands, as well as on the structure of their planktonic and benthic microbial communities, and on the function…

Editorial: Changing Plankton Communities: Causes, Effects and Consequences

2019

Eutrophication and browning influence Daphnia nutritional ecology

2019

Climate change and land-use practices can enhance lake eutrophication and browning, which influence phytoplankton composition by decreasing the availability of food high in nutritional quality (algae) and increasing the abundance of low-quality food (terrestrial detritus, bacteria) for herbivorous zooplankton. Nutritionally valuable algae for zooplankton are rich in essential biomolecules such as amino acids, polyunsaturated fatty acids (PUFAs), sterols, and phosphorus. We performed laboratory experiments and showed a stronger positive relationship between zooplankton (Daphnia) cumulative offspring number and availability of high-quality algae (Cryptophytes: Rhodomonas/Cryptomonas; and Chry…

BIOCLEANING

2017

Cleaning is one of the first and most important steps in conservative restora- tion intervention, as it removes the unwanted layers of dirt and deposit from the surface of an artefact. It must be done selectively, however, by adapting the cleaning operation to the different zones and removing successive layers of deposit without acting directly on the original materials of the surface. Generally, cleaning protocols are based on chemical or physical procedures with potential negative effects for restorers’ health and/or for the materials constituting the artworks. As an alternative, solvent gels, rigid gels and resin soaps can be used for selective cleaning. In recent decades, biological cle…

A comprehensive comparison between halophilic granular and flocculent sludge in withstanding short and long-term salinity fluctuations

2018

The effects of salinity fluctuations on the activity of autochthonous halophilic bacteria in aerobic granular sludge (AGS) and flocculent activated sludge (FAS) reactors were investigated. The response of nitrifiers and denitrifiers activity to drastic and moderate salinity shocks in the short-term (ST) and long-term (LT) was examined. The BOD5removal efficiency decreased only in the reactors subjected to the drastic LT salinity increase. Nevertheless, stable performances were achieved 18 days after the shock in the AGS-R1 (90%), whereas after 27 days in the FAS-R1 (82%). The loss in nitritation efficiency was higher in the FAS reactors and was proportional to the shock intensity. Nitritati…

Beyond cells – The virome in the human holobiont

2019

Viromics, or viral metagenomics, is a relatively new and burgeoning field of research that studies the complete collection of viruses forming part of the microbiota in any given niche. It has strong foundations rooted in over a century of discoveries in the field of virology and recent advances in molecular biology and sequencing technologies. Historically, most studies have deconstructed the concept of viruses into a simplified perception of viral agents as mere pathogens, which demerits the scope of large-scale viromic analyses. Viruses are, in fact, much more than regular parasites. They are by far the most dynamic and abundant entity and the greatest killers on the planet, as well as th…

Transformation of Construction Cement to a Self-Healing Hybrid Binder

2019

A new biomimetic strategy to im prove the self-healing properties of Portland cement is presented that is based on the application of the biogenic inorganic polymer polyphosphate (polyP), which is used as a cement admixture. The data show that synthetic linear polyp, with an average chain length of 40, as well as natural long-chain polyP isolated from soil bacteria, has the ability to support self-healing of this construction material. Furthermore, polyP, used as a water-soluble Na-salt, is subject to Na+/Ca2+ exchange by the Ca2+ from the cement, resulting in the formation of a water-rich coacervate when added to the cement surface, especially to the surface of bacteria-containing cement/c…

Happens in the best of subfamilies: establishment and repeated replacements of co-obligate secondary endosymbionts within Lachninae aphids.

2016

SummaryVirtually all aphids maintain an obligate mutualistic symbiosis with bacteria from theBuchneragenus, which produce essential nutrients for their aphid hosts. Most aphids from the Lachninae subfamily have been consistently found to house additional endosymbionts, mainlySerratia symbiotica. This apparent dependence on secondary endosymbionts was proposed to have been triggered by the loss of the riboflavin biosynthetic capability byBuchnerain the Lachninae last common ancestor. However, an integral large-scale analysis of secondary endosymbionts in the Lachninae is still missing, hampering the interpretation of the evolutionary and genomic analyses of these endosymbionts. Here, we anal…