Search results for " microbiologia"
showing 10 items of 907 documents
Starter cultures as biocontrol strategy to prevent Brettanomyces bruxellensis proliferation in wine
2017
Brettanomyces bruxellensis is a common and significant wine spoilage microorganism. B. bruxellensis strains generally detain the molecular basis to produce compounds that are detrimental for the organoleptic quality of the wine, including some classes of volatile phenols that derive from the sequential bioconversion of specific hydroxycinnamic acids such as ferulate and p-coumarate. Although B. bruxellensis can be detected at any stage of the winemaking process, it is typically isolated at the end of the alcoholic fermentation (AF), before the staring of the spontaneous malolactic fermentation (MLF) or during barrel aging. For this reason, the endemic diffusion of B. bruxellensis leads to c…
Composition and geographic variation of the bacterial microbiota associated with the coelomic fluid of the sea urchin Paracentrotus lividus
2020
AbstractIn the present work, culture-based and culture-independent investigations were performed to determine the microbiota structure of the coelomic fluid of Mediterranean sea urchin Paracentrotus lividus individuals collected from two distinct geographical sites neighboring a high-density population bay and a nature reserve, respectively. Next Generation Sequencing analysis of 16S rRNA gene (rDNA) showed that members of the Proteobacteria, Bacteroidetes and Fusobacteria phyla, which have been previously reported to be commonly retrieved from marine invertebrates, dominate the overall population of microorganisms colonizing this liquid tissue, with minority bacterial genera exhibiting rem…
Changes in soil mineral N content and abundances of bacterial communities involved in N reactions under laboratory conditions as predictors of soil N…
2016
Proper management of soil fertility requires specific tools for predicting N availability for crops as a consequence of different fertilization strategies. More information is required, especially for organic fertilizers, depending on their mineralization rate, composition, and processing (i.e., fresh or composted manure), as well as their effects on soil properties. Laboratory soil incubations were used as a proxy for understanding plant–soil N dynamics under field conditions. Chemical and microbiological measurements as contents of mineral N, potentially mineralizable N and the abundance of key genes regulating the overall N cycle were used as predictors of mineral N availability to maize…
Predictive shelf life model based on RF technology for improving the management of food supply chain: A case study
2016
The aim of this paper was the development of a Smart Logistic Unit (SLU) based on RF technology to support the management of the food supply chain, in order to guarantee the shelf life of products in agreement with logistic efficiency and system sustainability. For this purpose, the main parameters that influence the quality of perishable products were determined and a shelf life equation based on Volatile Organic Compounds (VOCs) was modelled. The levels of VOCs were gathered by the sensors allocated inside the SLU, which configures as the remote element of a system for identification and data transmission. The proposed model was then validated through an experimental test, simulating the …
A Metagenomic-Based Approach for the Characterization of Bacterial Diversity Associated with Spontaneous Malolactic Fermentations in Wine
2019
This study reports the first application of a next generation sequencing (NGS) analysis. The analysis was designed to monitor the effect of the management of microbial resources associated with alcoholic fermentation on spontaneous malolactic consortium. Together with the analysis of 16S rRNA genes from the metagenome, we monitored the principal parameters linked to MLF (e.g., malic and lactic acid concentration, pH). We encompass seven dissimilar concrete practices to manage microorganisms associated with alcoholic fermentation: Un-inoculated must (UM), pied-de-cuve (PdC), Saccharomyces cerevisiae (SC), S. cerevisiae and Torulaspora delbrueckii co-inoculated and sequentially inoculated, as…
The gut microbiota of the wood-feeding termite Reticulitermes lucifugus (Isoptera; Rhinotermitidae)
2016
Termite gut is host to a complex microbial community consisting of prokaryotes, and in some cases flagellates, responsible for the degradation of lignocellulosic material. Here we report data concerning the analysis of the gut microbiota of Reticulitermes lucifugus (Rossi), a lower termite species that lives in underground environments and is widespread in Italy, where it causes damage to wood structures of historical and artistic monuments. A 16S rRNA gene clone library revealed that the R. lucifugus gut is colonized by members of five phyla in the domain Bacteria: Firmicutes (49 % of clones), Proteobacteria (24 %), Spirochaetes (14 %), the candidatus TG1 phylum (12 %), and Bacteroidetes (…
New ΦBT1 site-specific integrative vectors with neutral phenotype in Streptomyces.
2016
Integrative plasmids are one of the best options to introduce genes in low copy and in a stable form into bacteria. The ΦC31-derived plasmids constitute the most common integrative vectors used in Streptomyces. They integrate at different positions (attB and pseudo-attB sites) generating different mutations. The less common ΦBT1-derived vectors integrate at the unique attB site localized in the SCO4848 gene (S. coelicolor genome) or their orthologues in other streptomycetes. This work demonstrates that disruption of SCO4848 generates a delay in spore germination. SCO4848 is co-transcribed with SCO4849, and the spore germination phenotype is complemented by SCO4849. Plasmids pNG1-4 were crea…
Viral resistance in HCV infection.
2018
The introduction of new multi-genotypic direct acting antivirals (DAA) in clinical practice has revolutionized HCV treatment, permitting the achievement of >95% rates of sustained virological response in many patients. However, virological failures can occur particularly if the treatments are sub optimal and/or with too short duration. Failure is often associated with development of resistance. The wide genetic variability in terms of different genotypes and subtypes, together with the natural presence and/or easy development of resistance during treatment, are intrinsic characteristics of HCV that may affect the treatment outcome and the chances of achieving a virological cure. This review…
Microbial communities of polluted sub-surface marine sediments
2018
Abstract Microbial communities of coastal marine sediment play a key role in degradation of petroleum contaminants. Here the bacterial and archaeal communities of sub-surface sediments (5–10 cm) of the chronically polluted Priolo Bay (eastern coast of Sicily, Italy), contaminated mainly by n-alkanes and biodegraded/weathered oils, were characterized by cultural and molecular approaches. 16S-PCR-DGGE analysis at six stations, revealed that bacterial communities are highly divergent and display lower phylogenetic diversity than the surface sediment; sub-surface communities respond to oil supplementation in microcosms with a significant reduction in biodiversity and a shift in composition; the…
Isolation, identification and oenological characterization of non-Saccharomyces yeasts in a Mediterranean island
2016
UNLABELLED We isolated, identified and characterized yeast strains from grapes, and their fermented musts, sampled in the small island of Linosa, where there are no wineries and therefore the possibility of territory contamination by industrial strains is minimal. By traditional culture-dependent methods, we isolated 3805 colonies, distinguished by molecular methods in 17 different species. Five hundred and forty-four isolates were analysed for the main oenological characteristics such as fermentative vigour with and without sulphites, sugar consumption and production of alcohol, volatile acidity, hydrogen sulphide, glycerol and β-glucosidase. This analysis identified Kluyveromyces marxianu…