Search results for " biotechnology"
showing 10 items of 3723 documents
The influence of bacteria-dominated diets on Daphnia magna somatic growth, reproduction, and lipid composition
2012
We explored how dietary bacteria affect the life history traits and biochemical composition of Daphnia magna, using three bacteria taxa with very different lipid composition. Our objectives were to (1) examine whether and how bacteria-dominated diets affect Daphnia survival, growth, and fecundity, (2) see whether bacteria-specific fatty acid (FA) biomarkers accrued in Daphnia lipids, and (3) explore the quantitative relationship between bacteria availability in Daphnia diets and the amounts of bacterial FA in their lipids. Daphnia were fed monospecific and mixed diets of heterotrophic (Micrococcus luteus) or methanotrophic bacteria (Methylomonas methanica and Methylosinus trichosporium) and…
Exclusion of Saccharomyces kudriavzevii from a wine model system mediated by Saccharomyces cerevisiae.
2010
This study investigated the competition and potential hybrid generation between the species Saccharomyces cerevisiae and S. kudriavzevii in a wine-model environment. Our main goal was to understand why S. kudriavzevii has not been found in wine fermentations whilst their hybrids are present. Auxotrophic mutants (Ura(-) and Lys(-)) were used to favour the selection of hybrids and to specifically differentiate the two species in mixed fermentations carried out at different temperatures (17 °C, 24 °C and 31 °C). Both yeasts showed a reduction in their maximum specific growth rates in mixed fermentations, indicating a clear antagonistic effect between the two microorganisms. Temperature played …
Culture and odor categorization : agreement between cultures depends upon the odors
2003
This study evaluated the effect of culture on the relationship between psychological dimensions underlying odor perception and odor categorization. In a first experiment, French, Vietnamese and American participants rated several perceptual dimensions of everyday odorants, and sorted these odorants on the basis of their similarity. Results showed that the three groups of participants differed in their perceptual judgments but agreed in categorizing the odors into four consensual groups (floral, sweet, bad, and nature). Three dimensions––pleasantness, edibility, cosmetic acceptability––discriminated these groups in the same way in the three countries. In a second experiment, the participants…
Wine Quality Perception: A Sensory Point of View
2016
Wine is a complex product, which had moved from a nutritional food to a hedonic beverage in consumer representation. This fact has increased the demand of quality products in the market. In this context, it is of high interest for wine producers to understand the underlying indicators of consumers’ quality perception as well as the relative importance they attach to these cues when inferring quality in wine to reach the alignment of consumers’ expectations, needs and wants. This chapter is aimed at giving an overview of the current state of knowledge of the indicators of wine quality perception from a sensory point of view. For this purpose, the factors driving perceived quality of wine as …
In vitro antitumor effects of the cold-water extracts of Mediterranean species of genus Pleurotus (higher Basidiomycetes) on human colon cancer cells
2014
The aim of this study was to evaluate whether the cold-water extracts of Pleurotus eryngii var. ferulae (CWE-Pef) and Pleurotus nebrodensis (CWE-Pn), 2 of the most prized wild and cultivated edible mushrooms, can affect the tumor phenotype of human colon cancer HCT116 cells. Our results showed that treatment with CWE- Pef and CWE-Pn resulted in a significant inhibition of the viability of HCT116 cells and promoted apoptosis, as also demonstrated by the increase of Bax-to-Bcl-2 messenger RNA ratio. Moreover, we observed that both extracts were able to inhibit cell migration and to affect homotypic and heterotypic cell-cell adhesion. It also was found that treatment with CWE-Pef and CWE-Pn ne…
Different species and symbiotic genotypes of field rhizobia can nodulate Phaseolus vulgaris in Tunisian soils.
2002
Abstract A collection of 160 isolates of rhizobia nodulating Phaseolus vulgaris in three geographical regions in Tunisia was characterized by restriction fragment length polymorphism analysis of polymerase chain reaction (PCR)-amplified 16S rDNA, nifH and nodC genes. Nine groups of rhizobia were delineated: Rhizobium gallicum biovar (bv.) gallicum, Rhizobium leguminosarum bv. phaseoli and bv. viciae, Rhizobium etli bv. phaseoli, Rhizobium giardinii bv. giardinii, and four groups related to species of the genus Sinorhizobium, Sinorhizobium meliloti, Sinorhizobium medicae and Sinorhizobium fredii. The most abundant rhizobial species were R. gallicum, R. etli, and R. leguminosarum encompassing…
Paracentrin 1, a synthetic antimicrobial peptide from the sea-urchin Paracentrotus lividus, interferes with staphylococcal and Pseudomonas aeruginosa…
2014
The rise of antibiotic-resistance as well as the reduction of investments by pharmaceutical companies in the development of new antibiotics have stimulated the investigation for alternative strategies to conventional antibiotics. Many antimicrobial peptides show a high specificity for prokaryotes and a low toxicity for eukaryotic cells and, due to their mode of action the development of resistance is considered unlikely. We recently characterized an antimicrobial peptide that was called Paracentrin 1 from the 5-kDa peptide fraction from the coelomocyte cytosol of the Paracentrotus lividus. In this study, the chemically synthesized Paracentrin 1, was tested for its antimicrobial and antibiof…
An overview of organosulfur compounds from Allium spp.: From processing and preservation to evaluation of their bioavailability, antimicrobial, and a…
2019
The use of Allium species and their extracts has been known since immemorial times due to their health beneficial properties. It is known that functional properties of Allium genus come from the high content of bioactive compounds. The biological activity of Allium extracts will be conditioned by the type of Allium variety, agricultural conditions, and specific extraction process used since all these factors affect the content and the profile of bioactive compounds. Innovative extraction techniques in comparison to conventional processes could be considered as a promising tool to recover bioactive compounds from Allium spp. with antimicrobial and anti-inflammatory properties. Trying to fill…
Aspects of excessive antibiotic consumption and environmental influences correlated with the occurrence of resistance to antimicrobial agents
2021
International audience; This article explores the correlation between specific aspects of antibiotic usage, their resistance development, and environmental factors. The indiscriminate use of antibiotics led to environment contamination, selection and spreading of antibiotic-resistant organisms, and alteration of the microbial ecosystems balance. Sociobehavioural environmental factors and changes in the natural environment are major contributors to resistance development. Resistant bacteria strains' isolation in food, water, soil etc. demonstrates the environmental influence on the strains through antibiotics accumulation in the environment. It is difficult to assess the impact of antibiotic…
Impact of vCJD on blood supply.
2007
Variant Creutzfeldt-Jakob disease (vCJD) is an at present inevitably lethal neurodegenerative disease which can only be diagnosed definitely post mortem. The majority of the approximately 200 victims to date have resided in the UK where most contaminated beef materials entered the food chain. Three cases in the UK demonstrated that vCJD can be transmitted by blood transfusion. Since BSE and vCJD have spread to several countries outside the UK, it appears advisable that specific risk assessments be carried out in different countries and geographic areas. This review explains the approach adopted by Germany in assessing the risk and considering precautionary measures. A fundamental premise is…