Search results for "mikrobit"

The responses of shoot-root-rhizosphere continuum to simultaneous fertilizer addition, warming, ozone and herbivory in young Scots pine seedlings in …

2017

Abstract It is not clear how climate change in combination with increasing soil nitrogen availability and herbivory affects boreal forests, the largest terrestrial biome in the world. In this study, Scots pine ( Pinus sylvestris ) seedlings were exposed to moderate warming (ca. 1 °C), 1.5 × ambient ozone (O 3 ) concentration, fertilizer addition (120 kg N ha −1 yr −1 ) and shoot herbivory by pine sawfly ( Acantholyda posticalis ) alone and in combination. We measured fine root morphology, mycorrhizal colonization level, root fungal biomass (ergosterol), rhizosphere emission of biogenic volatile organic compounds (BVOCs), and microbial biomass (PLFAs) in the rhizosphere soil as well as seedl…

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 (…

Effects of alternative electron acceptors on the activity and community structure of methane-producing and consuming microbes in the sediments of two…

2017

The role of anaerobic CH4 oxidation in controlling lake sediment CH4 emissions remains unclear. Therefore, we tested how relevant EAs (SO42−, NO3−, Fe3+, Mn4+, O2) affect CH4 production and oxidation in the sediments of two shallow boreal lakes. The changes induced to microbial communities by the addition of Fe3+ and Mn4+ were studied using next-generation sequencing targeting the 16S rRNA and methyl-coenzyme M reductase (mcrA) genes and mcrA transcripts. Putative anaerobic CH4-oxidizing archaea (ANME-2D) and bacteria (NC 10) were scarce (up to 3.4% and 0.5% of archaeal and bacterial 16S rRNA genes, respectively), likely due to the low environmental stability associated with shallow depths.…

Prokaryotic assemblages within permafrost active layer at Edmonson Point (Northern Victoria Land, Antarctica)

2018

This study was aimed at gaining insights on the prokaryotic community (in terms of both taxonomic composition and activities) inhabiting the active layer at Edmonson Point, an ice-free area on the eastern slope at the foot of Mount Melbourne (Northern Victoria Land, Antarctica). Samples were collected during the thawing period, when microbial physiological activities are restored to utilize previously frozen organic substrates. Despite the very small cell sizes (600 daltons) substrates, as indicated also by the obtained rates of enzymatic hydrolytic activities over proteolytic, glycolitic and phosphoric compounds. Taxonomical composition showed that Proteobacteria, Actinobacteria and Firmic…

Genetic diversity and phenotypic characterization of Iodobacter limnosediminis associated with skin lesions in freshwater fish

2021

The relatively unknown genus Iodobacter sp. has been repeatedly isolated from skin ulcers and saprolegniosis on freshwater fish in Finland, especially farmed salmonids. Genetic characterization verified that all 23 bacterial isolates studied here belonged to the species Iodobacter limnosediminis, previously undescribed from the fish microbiota. Whole-genome pulsed-field gel electrophoresis revealed variability between the I. limnosediminis strains, suggesting that they were most likely of environmental origin. Two I. limnosediminis strains caused lesions in 27%–53% of brown trout (Salmo trutta) injected intramuscularly (p ≤ .05). The lesions represented moderate to severe tissue damage, but…

Prokaryoottien PCR-perustaisten havaintomenetelmien kehittäminen ja eliöiden tunnistaminen syvän kaivoksen kivi- ja vesinäytteistä

2008

Comparing the Ecotoxicological Effects of Perfluorooctanoic Acid (PFOA) and Perfluorohexanoic Acid (PFHxA) on Freshwater Microbial Community

2022

The ubiquitous presence of perfluorinated carboxylic acids (PFCAs) around the globe has attracted increasing attention, due to their persistency, bioaccumulation, and toxicity. Nevertheless, the ecotoxicological effects of the compounds on aquatic microorganisms has remained understudied. Hence, the present study focused on determining, and comparing, the effects of regulated long-chain PFCA, perfluorooctanoic acid (PFOA), and nonregulated short-chain PFCA, perfluorohexanoic acid (PFHxA), on the diversity, structure, microbial growth, and activity of a freshwater microbial community. In the experiment, lake water was incubated for a period of four weeks at three different concentrations of …

Upwelled plankton community modulates surface bloom succession and nutrient availability in a natural plankton assemblage

2022

Upwelling of nutrient-rich waters into the sunlit surface layer of the ocean supports high primary productivity in eastern boundary upwelling systems (EBUSs). However, subsurface waters contain not only macronutrients (N, P, Si) but also micronutrients, organic matter and seed microbial communities that may modify the response to macronutrient inputs via upwelling. These additional factors are often neglected when investigating upwelling impacts on surface ocean productivity. Here, we investigated how different components of upwelled water (macronutrients, organic nutrients and seed communities) drive the response of surface plankton communities to upwelling in the Peruvian coastal zone. Re…

Evolved high aerobic capacity has context-specific effects on gut microbiota

2022

Publisher Copyright: Copyright © 2022 Hanhimäki, Watts, Koskela, Koteja, Mappes and Hämäläinen. Gut microbiota is expected to coevolve with the host's physiology and may play a role in adjusting the host's energy metabolism to suit the host's environment. To evaluate the effects of both evolved host metabolism and the environmental context in shaping the gut microbiota, we used a unique combination of (1) experimental evolution to create selection lines for a fast metabolism and (2) a laboratory-to-field translocation study. Mature bank voles Myodes glareolus from lines selected for high aerobic capacity (A lines) and from unselected control (C lines) were released into large (0.2 ha) outdo…

DNA traces the origin of honey by identifying plants, bacteria and fungi

2021

The regional origin of a food product commonly affects its value. To this, DNA-based identification of tissue remains could offer fine resolution. For honey, this would allow the usage of not only pollen but all plant tissue, and also that of microbes in the product, for discerning the origin. Here we examined how plant, bacterial and fungal taxa identified by DNA metabarcoding and metagenomics differentiate between honey samples from three neighbouring countries. To establish how the taxonomic contents of honey reflect the country of origin, we used joint species distribution modelling. At the lowest taxonomic level by metabarcoding, with operational taxonomic units, the country of origin …