Search results for "microbial"
showing 10 items of 2041 documents
Relationships between soil water repellency and microbial community composition under different plant species in a Mediterranean semiarid forest
2014
Abstract Soil water repellency (SWR) can influence many hydrological soil properties, including water infiltration, uneven moisture distribution or water retention. In the current study we investigated how variable SWR persistence in the field is related to the soil microbial community under different plant species (P. halepensis, Q. rotundifolia, C. albidus and R. officinalis) in a Mediterranean forest. The soil microbial community was determined through phospholipid fatty acids (PLFA). The relationships between microbiological community structure and the soil properties pH, Glomalin Related Soil Protein (GRSP) and soil organic matter (SOM) content were also studied. Different statistical …
Soil carbon quality and nitrogen fertilization structure bacterial communities with predictable responses of major bacterial phyla
2014
Abstract Agricultural practices affect the soil ecosystem in multiple ways and the soil microbial communities represent an integrated and dynamic measure of soil status. Our aim was to test whether the soil bacterial community and the relative abundance of major bacterial phyla responded predictably to long-term organic amendments representing different carbon qualities (peat and straw) in combination with nitrogen fertilization levels and if certain bacterial groups were indicative of specific treatments. We hypothesized that the long-term treatments had created distinctly different ecological niches for soil bacteria, suitable for either fast-growing copiotrophic bacteria, or slow-growing…
Responses of microbial food web to increased allochthonous DOM in an oligotrophic subarctic lake
2013
Climate-induced changes in catchment area vegetation and runoff alter the quality and quantity of carbon that enters lakes, with implications for food webs in recipient water bodies. The effect of dissolved organic matter (DOM) on the ratio between heterotrophic and autotrophic biomass and productivity was studied in a subarctic, clear water lake in northern Finland. In a mesocosm experiment, natural DOM from a subarctic bog and a boreal lake was added to the lake water, doubling the initial dissolved organic carbon (DOC) concentration. Optical indices sug- gested that the subarctic DOM addition was more bioavailable, which was in line with the greater increase in bacterial biomass and prod…
Population- and ecosystem-level effects of predation on microbial-feeding nematodes.
2017
We studied the role of nematode predation in the functioning of detrital food webs assembled in microcosms. The microcosms contained defaunated humus and litter materials, a diverse microbial community with bacteria, fungi and protozoa, and a birch (Betula pendula) seedling infected with mycorrhizal fungi. Different levels of top-down control upon microbivorous nematodes were set up by assembling food webs either without predators, or in combinations with a specialist and a non-specialist predatory mite (Mesostigmata). The nematode community was composed of either (1) three species of bacterivorous, or (2) three species of fungivorous nematodes or (3) both groups together. After two growing…
Recent developments and applications of smart nanoparticles in biomedicine
2022
Abstract Over the last decades, nanotechnology applied in medicine (nanomedicine) has sparked great interest from the scientific community, thanks to the possibility to engineer nanostructured materials, including nanoparticles (NPs), for a specific application. Their small size confers them unique properties because they are subject to physical laws in the middle between classical and quantum physics. This review is proposed to explain better how to design a specific NP and clarify the relationship between the type, size, and shape of NPs and the specific medical applications. NPs are classified into inorganic (metallic NPs, quantum dots, carbon-based nanostructures, mesoporous silica NPs)…
Functional biopolymer-based nanocomposites incorporating graphene nanoplatelets
2016
The effectiveness of the antimicrobial activity over time is mainly determined by the release rate of the antimicrobial compounds. The rate of release depends on different factors such as preparation method, environmental conditions, interactions between antimicrobial and matrix. In this regard, nanoparticles can potentially be used to control the release of antimicrobial agents. Moreover, it is well known that the incorporation of nano-sized fillers into a biopolymeric matrix is an effective way to improve its properties. Aim of this work was to prepare and characterize biopolymer-based nanocomposites with antimicrobial properties. In particular, graphene nanoplatelets (GnPs) as fillers an…
Evaluation in microcosm of biostimulation and bioaugmentation efficacy on diesel-contaminated soil
2021
Bioremediation is a promising technology for the treatment of hydrocarbon (HC) contaminated soils that is based on the biodegradation capacities of native or introduced microbial populations. Biotractability tests are essential for choosing the optimal bioremediation treatment. For this purpose, multiple microcosm tests, based on biostimulation by landfarming or bioventing and addition of nutrients, were conducted for 120 days on a soil contaminated by diesel, after assessing its intrinsic catabolic potential. An additional bioaugmentation treatment was performed for further 60 days by inoculating selected HC degrading bacteria. HC (C10-C40) concentration was monitored by GC-FID analysis an…
Analisi di processo e dinamica della comunità batterica nel trattamento di sedimenti marini con reattori bioslurry
2020
Nella nota sono riportati i risultati di una sperimentazione condotta mediante la messa in esercizio di un reattore bioslurry per il trattamento di sedimenti marini contaminati da idrocarburi. Sono state valutate le performance di processo in termini di rimozione di TPH (86% con velocità di rimozione massima di 36 mgTPH kg-1 d-1) congiuntamente ad altre tipologie di indagini volte ad ottenere maggiori informazioni sulla natura dei processi che si sono sviluppati nel reattore. Nello specifico, è stato utilizzato un approccio di tipo microbiologico mediante l’adozione di una tecnica di sequenziamento di nuova generazione (NGS - Next Generation Sequencing). Dall’analisi dei dati biologici è st…
Long-term impact of 19 years' farmyard manure or sewage sludge application on the structure, diversity and density of the protocatechuate-degrading b…
2012
International audience; Impact of long-term biosolids application on soil-living micro-organisms key players of ecosystemic services is scarcely reported. Here, the impact of the 19 year-long application of farmyard manure (FM) and sewage sludge (SS) organic fertilisation regimes on the protocatechuate-degrading bacterial (pca) community was estimated by comparison to a mineral fertilisation regime (U). The structure, diversity and density of the pca community were determined using pcaH, a gene encoding the protocatechuate 3,4-dioxygenase. Ten years after the last application, the structure of the pca community in soils amended with 55100 (100 t/ha/2 years) and to a lesser extent with FM (1…
Spatial patterns of bacterial taxa in nature reflect ecological traits of deep branches of the 16S rRNA bacterial tree
2009
International audience; Whether bacteria display spatial patterns of distribution and at which level of taxonomic organization such patterns can be observed are central questions in microbial ecology. Here we investigated how the total and relative abundances of eight bacterial taxa at the phylum or class level were spatially distributed in a pasture by using quantitative PCR and geostatistical modelling. The distributions of the relative abundance of most taxa varied by a factor of 2.5–6.5 and displayed strong spatial patterns at the field scale. These spatial patterns were taxon-specific and correlated to soil properties, which indicates that members of a bacterial clade defined at high t…