1,721,014 research outputs found
Influence of seasonality, environmental and anthropic factors on crop damage by wild boar Sus scrofa
No full textIn recent decades, wild boar Sus scrofa populations have increased both in number and distribution in Italy, thus enhancing problems of cohabitation with humans. Crop damage represents one of the main sources of conflict; understanding the spatiotemporal variation of damage events and which factors increase the risk of damage is crucial to the development of effective management strategies. The aims of this study were to determine the impact of wild boar on croplands in the Special Protection Area “Risaie della Lomellina” (western Po Plain, northern Italy) and to formulate a risk prediction model through a binary logistic regression analysis. Damage events almost exclusively involved maize, and were concentrated in spring and summer. Sporadic cases of damage concerned rice, soybean and sorghum fields. The risk of damage was higher in fields close to forests, far from main roads, urban areas and continuous hedgerows, and in areas with low human population densities
A combination of SEM technique and X-ray microanalysis to study spore germination process of Clostridium tyrobutyricum
No full textArray-based transcriptional analysis of Clostridium sporogenes UC9000 during germination, cell outgrowth and vegetative life
No full textThe members of the genus Clostridium, including the spore-forming anaerobic bacteria, have a complex and strictly regulated life cycle, but very little is known about the genetic pathways involved in the different stages of their life cycle. Clostridium sporogenes, a Gram-positive bacterium usually involved in food spoilage and frequently isolated from late blowing cheese, is genetically indistinguishable from the proteolytic Clostridium botulinum. As the non-neurotoxic counterpart, it is often used as an exemplar for the toxic subtypes. In this work, we performed a microscopic study combined with a custom array-based analysis of the C. sporogenes cycle, from dormant spores to the early stationary phase.We identified a total of 211 transcripts in spores, validating the hypothesis that mRNAs are abundant in spores and the pattern of mRNA expression is strikingly different from that present in growing cells. The spore transcripts included genes responsible for different life-sustaining functions, suggesting there was transcript entrapment or basic poly-functional gene activation for future steps. In addition, 3 h after the beginning of the germination process, 20% of the total up-regulated genes were temporally expressed in germinating spores. The vegetative condition appeared to be more active in terms of gene transcription and protein synthesis than the spore, and genes coding for germination and sporulation factors seemed to be expressed at this point. These results suggest that spores are not silent entities, and a broader knowledge of the genetic pathways involved in the Clostridium life cycle could provide a better understanding of pathogenic clostridia type
Array-based transcriptional analysis of Clostridium sporogenes/botulinum during its vegetative cycle, germination process and outgrowth
No full text
Assessing biochemical and biomolecular gradients along an ombrotrophic peat bog profile
No full textOmbrotrophic peat bogs are not directly in contact with groundwater: since their genesis is related only to wet and dry deposition they are considered natural archives of extreme importance for the assessment of past ecological, environmental and climatic events.
Etang de la Gruère is an ombrotrophic Swiss bog representing the longest continuous record of atmospheric deposition in continental Europe (corresponding to ca. 15,000 years of peat formation). Aim of the present study is to assess, in ca 20 samples along the peat bog profile, the presence and distribution of two very important classes of biomolecules: DNA and lipids. PCR-DGGE analysis of DNA targeting total bacteria and archaea allowed the identification of biodiversity patterns that clustered according to the profile depth and chemical analyses. It was found that the microbial communities changed significantly below ca 45 cm, where conditions are anoxic and molecules with higher molecular mass and degree of condensation are observed. Acidobacteria dominated the most superficial samples, while methanomicrobia were more common in the deepest samples. It was also found that the homologies scores decreased with depth, thus pointing to a less known microbial community composition in the oldest samples.
Lipid analyses are now being carried out to integrate and extend the findings at DNA level. Specifically the analyses are focusing on phospholipid fatty acids (PLFAs) and tetraether lipids, which are respectively indicators of bacterial and archaeal microbial communities. In the case of tetraether lipids, their possible application as “paleo-thermometers” is also being tested
Water and Cations Flux During Sporulation and Germination.
No full textBacterial spore water uptake and solute permeability are hypothesised to play a central role during the sporulation and germination processes but the leading mechanisms are at now poorly understood. In this chapter, a state of the art and the last experiments to better study this topic are presented. In the first part, major questions are addressed to the role of water content in spore dormancy and resistance, to the mechanisms which lead to spore dehydration and to the permeability of the spore layers to water and solutes. In the second part, the attention is focused on the ion composition of spores and their importance for the spore life cycle, with particular attention to the leading mechanisms acting during spore formation in the mother cell and during the germination process and outgrowth
Effects of geographic area, feedstock, temperature, and operating time on microbial communities of six full-scale biogas plants
Full text linkThe objective of this study was to investigate the effect of different animal feedings operated in two distinct PDO (protected designation of origin) cheese production areas (Parmigiano Reggiano and Grana Padano) on the microbiome of six full-scale biogas plants, by means of Illumina sequencing and qPCR techniques. The effects of feedstock (cattle slurry manure, energy crops, agro-industrial by-products), temperature (mesophilic/thermophilic), and operating time were also examined, as were the relationships between the predominant bacterial and archaeal taxa and process parameters. The different feedstocks and temperatures strongly affected the microbiomes. A more biodiverse archaeal population was highlighted in Parmigiano Reggiano area plants, suggesting an influence of the different animal feedings. Methanosarcina and Methanosaeta showed an opposite distribution among anaerobic plants, with the former found to be related to ammonium concentration. The Methanoculleus genus was more abundant in the thermophilic digester whereas representation of the Thermotogales order correlated with hydraulic retention time
Genome wide transcriptome analysis of bacillus cereus producing biofilm in food environment.
No full text: Background
B. cereus is a human pathogen most commonly associated with food poisoning that causes two types of food-borne infections: the emetic disease caused by a thermostable toxin production in food and the diarrhoeal syndrome which is the result of ingested B. cereus spores that germinate in the human intestine. The B. cereus mechanism of intoxication and infection is strongly influenced by its spore-producing and germinating cycle in food together with the capacity to form biofilm.
Objectives
1) Analysis of the biofilm formation capacity in food model.
2) Use a genome-wide microarray transcriptome analysis to explore transcriptional changes and molecular mechanism, behind the process of spore germination, outgrowth and toxin production.
3) Determination of the mRNA transcripts abundance and their role in dormant spores.
Methods
B. cereus UC10070 isolated from a food biofilm has been used. SEM and SEM-X-ray microanalysis (Bassi et al. 2009) were set to monitor the B. cereus biological cycle in food model. Combimatrix microarray 12K were applied to all samples and conditions analysed. The capacity of this strain to form biofilm has been assessed in flow cells.
Conclusions
B. cereus UC10070 was able to form biofilm on different abiotic materials and food matrices. Transcriptome and analysis of orthologous groups obtained, provide new basic knowledge on Bacillus cereus for what concerns genes responsible of germination and late-log/stationary phase. Pattern of major virulence genes involved in B. cereus-associated food borne disease have also been investigated
I microrganismi causa di malattie di origine alimentare
No full textL’Organizzazione Mondiale delle Sanità
(OMS) definisce le malattie di origine alimentare
(food born diseases) come malattie infettive
o intossicazioni causate dal consumo di alimenti
e di acqua. Queste possono essere suddivise
in:
•• infezioni alimentari, dovute all’ingestione
di cellule vitali o di particelle virali tramite
l’acqua o gli alimenti;
•• intossicazioni, connesse all’ingestione di
tossine prodotte dai microrganismi
nell’alimento.
Qui di seguito si presentano sinteticamente i
principi alla base dell’analisi del rischio microbiologico
negli alimenti e i principali agenti
patogeni microbici responsabili di tossinfezioni
alimentari.
L’obiettivo è fornire le informazioni scientifiche
necessarie per la gestione del rischio
microbiologico nella filiera di produzione degli
alimenti.
Non saranno trattati, se non brevemente, gli
aspetti clinici delle tossinfezioni alimentari
- …
