Search results for "microorganism"
showing 10 items of 449 documents
Filamentous fungi transported by birds during migration across the mediterranean sea.
2013
The potential for the transport and diffusion of some pathogenic microorganisms by migratory birds is of concern. Migratory birds may be involved in the dispersal of microorganisms and may play a role of mechanical and biological vectors. The efficiency of dispersal of pathogenic microorganisms depends on a wide range of biotic and abiotic factors that influence the survival or disappearance of a given agent in a geographical area. In the present study, 349 migratory birds were captured in four sites (Mazara del Vallo, Lampedusa, Ustica and Linosa), representing the main stop-over points during spring and autumnal migration, and analyzed for the presence of filamentous fungi. A total of 2,3…
Microbial analysis of raw cows' milk used for cheese-making: influence of storage treatments on microbial composition and other technological traits
2010
Raw milk used to produce Grana cheese was subjected to several treatment regimes, including varying temperatures and storage times. Milk from morning and evening milking were transferred to a dairy factory sepa- rately (double delivery) or together (single delivery), after storage at the farm for 12 h; in the former case, milk was stored at 12 or 8°C, whereas, in the latter, it was kept at ambient temperature or 18°C. Values of pH of the vat milk were lower for milk samples kept at room temperature, while other physico-chemical parameters and rheological characteristics tested did not show significant differ- ences linked to the different storage temperatures of milk used for ‘‘Grana Trenti…
Regulating feeding and increasing methane yield from co-digestion of C5 molasses and cattle manure
2014
Abstract The paper investigated the mesophilic (∼35 °C) and thermophilic (∼50 °C) co-digestion of cattle manure and C5 molasses for a variable organic loading rate (OLR). The small scale continuous reactor experiment revealed that thermophilic treatment yielded a maximum 313 ± 16 L/kg VS methane for the feeding ranged between 50% and 70% C5 (v/v). Mesophilic co-digestion, on the other hand, produced maximum 232 ± 32 L/kg VS methane when feeding was ranged between 31% and 47% C5 (v/v). The feeding strategy of this study was sophistically adjusted owing to the unstable volatile fatty acids (VFA) pattern, developed at different stages of the experiment. Attainable molasses feeding for both the…
Bacterial Diseases of Bioenergy Woody Plants in Ukraine
2023
In this study, the characterization of several bacterial diseases affecting silver birch (Betula pendula Roth.), common ash (Fraxinus excelsior L.), white poplar (Populus alba L.), and white willow (Salix alba L.) in Ukraine were described. The typical symptoms, features of pathogenesis, and characteristics of the causative agents of the most common bacterial diseases of these tree species were shown. The following types of bacterioses were noted to be especially dangerous, namely, bacterial wetwood, fire blight, bacterial canker, and tuberculosis. Bacterial necrosis of the bark was a less dangerous disease. At the same time, all of the listed types of bacterioses were registered within the…
Hacia el entendimiento del control de la expresión génica del regulón clanobacteriano del nitrógeno mediado por el factor de transcripción NtcA y la …
2018
NtcA, es un factor de transcripción cianobacteriano perteneciente a la familia CRP. Es considerado el regulador global del nitrógeno en cianobacterias ya que presenta un regulón muy amplio que incluye muchos genes implicados en el metabolismo de nitrógeno. Se activa por 2-oxoglutarato(2-OG), un indicador del nivel de nitrógeno celular y es coactivado por una proteína llamada PipX, objeto importante de este estudio. A bajo nivel de 2-OG, PipX es secuestrada por la proteína señalizadora PII quedando inaccesible para activar NtcA. Sin embargo, la unión de 2-OG a PII en condiciones de escasez de nitrógeno, libera PipX, la cual queda accesible para coactivar NtcA. Las estructuras de NtcA unido a…
Impact of barley (Hordeum vulgare L.) transgenic line H228.2A on substrate and rhizosphere microorganisms and the possibility of horizontal gene tran…
2013
Numerous investigations have been carried out to determine the impact of genetically modified plants, such as potato, maize, alfalfa and tobacco, on soil microorganisms and the results are contradictory. We applied classical microbiology methods to study quantitative changes of bacterial and fungal abundance in substrate and rhizosphere from barley (Hordeum vulgare L.) transgenic line H228.2A containing Rpg1 and bar genes, and its parent nontransgenic variety ‘Golden Promise’. In addition, molecular biology methods were used to determine, if horizontal gene transfer from barley transgenic line to soil bacteria has occurred under experimental conditions by screening bacterial genomes for the…
Modelling the interactions of soil microbes and nematodes
2009
Abstract Six different soil food webs, assembled from a bacterium, a bacterial-feeding nematode, a fungus and a fungal-feeding nematode, were established in replicated laboratory microcosms. Glucose was supplied as the sole carbon source for the microbes. Biomasses of the organisms and the concentration of dissolved organic carbon (DOC) were measured ten times during 20 weeks. A discrete dynamic model based on the material flow between system components was fitted to the experimental data. Bacterial-based food chains were largely inactive in the absence of fungi, but mutual facilitation was observed in the systems with both fungus and bacterium. The population dynamics of a fungal-feeding …
Effects of the introduction of a biocontrol strain of Trichoderma atroviride on non target soil micro-organisms
2009
International audience; The main objective of this study was to assess the impact of the application of an antagonistic strain of Trichoderma atroviride on the native microbial soil communities. The structures of the fungal and bacterial communities were assessed by T-RFLP (terminal restriction fragment length polymorphism) method, based on T-RFLP analysis of 18S and 16S rRNA genes, respectively. Results showed that the introduction of the strain I-1237 into two soils slightly modified the microbial diversity, only for a short period of time. Nine months post-inoculation resilience took place, resulting in similar structures of the fungal and bacterial communities in the inoculated and cont…
Characterization of the Viable but Nonculturable (VBNC) State in Saccharomyces cerevisiae
2013
The Viable But Non Culturable (VBNC) state has been thoroughly studied in bacteria. In contrast, it has received much less attention in other microorganisms. However, it has been suggested that various yeast species occurring in wine may enter in VBNC following sulfite stress.In order to provide conclusive evidences for the existence of a VBNC state in yeast, the ability of Saccharomyces cerevisiae to enter into a VBNC state by applying sulfite stress was investigated. Viable populations were monitored by flow cytometry while culturable populations were followed by plating on culture medium. Twenty-four hours after the application of the stress, the comparison between the culturable populat…
Recovery Estimation of Dried Foodborne Pathogens Is Directly Related to Rehydration Kinetics.
2016
International audience; Drying is a common process which is used to preserve food products and technological microorganisms, but which is deleterious for the cells. The aim of this study is to differentiate the effects of drying alone from the effects of the successive and necessary rehydration. Rehydration of dried bacteria is a critical step already studied in starter culture but not for different kinetics and not for pathogens. In the present study, the influence of rehydration kinetics was investigated for three foodborne pathogens involved in neonatal diseases caused by the consumption of rehydrated milk powder: Salmonella enterica subsp. enterica serovar Typhimurium, Salmonella enteri…