Search results for "bakteerit"
showing 10 items of 165 documents
Further insights in the Tardigrada microbiome: phylogenetic position and prevalence of infection of four new Alphaproteobacteria putative endosymbion…
2019
Abstract Data from a previous study showed that microbiomes of six tardigrade species are species-specific and distinct from associated environmental microbes. We here performed a more in-depth analyses of those data, to identify and characterize new potential symbionts. The most abundant bacterial operational taxonomic units (OTUs) found in tardigrades are classified, and their prevalence in other environments is assessed using public databases. A subset of OTUs was selected for molecular phylogenetic analyses based on their affiliation with host-associated bacterial families in tardigrades. Almost 22.6% of the most abundant OTUs found do not match any sequence at 99% identity in the IMNGS…
Biological control of potato soft rot caused by Dickeya solani and the survival of bacterial antagonists under cold storage conditions
2018
Dickeya and Pectobacterium are responsible for causing blackleg of plants and soft rot of tubers in storage and in the field, giving rise to losses in seed potato production. In an attempt to improve potato health, biocontrol activity of known and putative antagonists was screened using in vitro and in planta assays, followed by analysis of their persistence at various storage temperatures. Most antagonists had low survival on potato tuber surfaces at 4 °C. The population dynamics of the best low‐temperature tolerant strain and also the most efficient antagonist, Serratia plymuthica A30, along with Dickeya solani as target pathogen, was studied with TaqMan real‐time PCR throughout the stora…
Propagule pressure increase and phylogenetic diversity decrease community’s susceptibility to invasion
2017
Background Invasions pose a large threat to native species, but the question of why some species are more invasive, and some communities more prone to invasions than others, is far from solved. Using 10 different three-species bacterial communities, we tested experimentally if the phylogenetic relationships between an invader and a resident community and the propagule pressure affect invasion probability. Results We found that greater diversity in phylogenetic distances between the members of resident community and the invader lowered invasion success, and higher propagule pressure increased invasion success whereas phylogenetic distance had no clear effect. In the later stages of invasion,…
New insight to the role of microbes in the methane exchange in trees: evidence from metagenomic sequencing
2021
Methane (CH4) exchange in tree stems and canopies and the processes involved are among the least understood components of the global CH4 cycle. Recent studies have focused on quantifying tree stems as sources of CH4 and understanding abiotic CH4 emissions in plant canopies, with the role of microbial in situ CH4 formation receiving less attention. Moreover, despite initial reports revealing CH4 consumption, studies have not adequately evaluated the potential of microbial CH4 oxidation within trees. In this paper, we discuss the current level of understanding on these processes. Further, we demonstrate the potential of novel metagenomic tools in revealing the involvement of microbes in the C…
Borrelia afzeliialters reproductive success in a rodent host
2018
The impact of a pathogen on the fitness and behaviour of its natural host depends upon the host–parasite relationship in a given set of environmental conditions. Here, we experimentally investigated the effects ofBorrelia afzelii,one of the aetiological agents of Lyme disease in humans, on the fitness of its natural rodent host, the bank vole (Myodes glareolus), in semi-natural conditions with two contrasting host population densities. Our results show thatB. afzeliican modify the reproductive success and spacing behaviour of its rodent host, whereas host survival was not affected. Infection impaired the breeding probability of large bank voles. Reproduction was hastened in infected females…
Comparable response of wild rodent gut microbiome to anthropogenic habitat contamination
2021
Abstract Species identity is thought to dominate over environment in shaping wild rodent gut microbiota, but it remains unknown whether the responses of host gut microbiota to shared anthropogenic habitat impacts are species-specific or if the general gut microbiota response is similar across host species. Here, we compare the influence of exposure to radionuclide contamination on the gut microbiota of four wild mouse species: Apodemus flavicollis, A. sylvaticus, A. speciosus and A. argenteus. Building on the evidence that radiation impacts bank vole (Myodes glareolus) gut microbiota, we hypothesized that radiation exposure has a general impact on rodent gut microbiota. Because we sampled (…
Cryptogams signify key transitions of bacteria and fungi in Arctic sand dune succession.
2020
•Primary succession models focus on aboveground vascular plants. However, the prevalence of mosses and lichens, i.e. cryptogams, suggests they play a role in soil successions. Here, we explore whether effects of cryptogams on belowground microbes can facilitate progressive shifts in sand dune succession. •We linked aboveground vegetation, belowground bacterial and fungal communities, and soil chemical properties in six successional stages in Arctic inland sand dunes: bare sand, grass, moss, lichen, ericoid heath and mountain birch forest. •Compared to the bare sand and grass stages, microbial biomass and the proportion of fungi increased in the moss stage, and later stage microbial groups a…
Broad thermal tolerance is negatively correlated with virulence in an opportunistic bacterial pathogen
2018
Predicting the effects of global increase in temperatures on disease virulence is challenging, especially for environmental opportunistic bacteria, because pathogen fitness may be differentially affected by temperature within and outside host environment. So far, there is very little empirical evidence on the connections between optimal temperature range and virulence in environmentally growing pathogens. Here, we explored whether the virulence of an environmentally growing opportunistic fish pathogen, Flavobacterium columnare, is malleable to evolutionary changes via correlated selection on thermal tolerance. To this end, we experimentally quantified the thermal performance curves (TPCs) f…
The Importance of Phytoplankton Biomolecule Availability for Secondary Production
2017
The growth and reproduction of animals is affected by their access to resources. In aquatic ecosystems, the availability of essential biomolecules for filter-feeding zooplankton depends greatly on phytoplankton. Here, we analyzed the biochemical composition, i.e., the fatty acid, sterol and amino acid profiles and concentrations as well as protein, carbon, nitrogen, and phosphorus content of 17 phytoplankton monocultures representing the seven most abundant phytoplankton classes in boreal and sub-arctic lakes. To examine how the differences in the biochemical composition between phytoplankton classes affect their nutritional quality for consumers, we assessed the performance of Daphnia, on …
Does catchment geodiversity foster stream biodiversity?
2019
Abstract Context One approach to maintain the resilience of biotic communities is to protect the variability of abiotic characteristics of Earth’s surface, i.e. geodiversity. In terrestrial environments, the relationship between geodiversity and biodiversity is well recognized. In streams, the abiotic properties of upstream catchments influence stream communities, but the relationships between catchment geodiversity and aquatic biodiversity have not been previously tested. Objectives The aim was to compare the effects of local environmental and catchment variables on stream biodiversity. We specifically explored the usefulness of catchment geodiversity in explaining the species richness on …