Search results for "nema"

Differential Contribution of the Parental Genomes to a S. cerevisiae × S. uvarum Hybrid, Inferred by Phenomic, Genomic, and Transcriptomic Analyses, …

2020

In European regions of cold climate, S. uvarum can replace S. cerevisiae in wine fermentations performed at low temperatures. S. uvarum is a cryotolerant yeast that produces more glycerol, less acetic acid and exhibits a better aroma profile. However, this species exhibits a poor ethanol tolerance compared with S. cerevisiae. In the present study, we obtained by rare mating (non-GMO strategy), and a subsequent sporulation, an interspecific S. cerevisiae × S. uvarum spore-derivative hybrid that improves or maintains a combination of parental traits of interest for the wine industry, such as good fermentation performance, increased ethanol tolerance, and high glycerol and aroma productions. G…

Origin of modern syphilis and emergence of a pandemic Treponema pallidum cluster

2016

The abrupt onslaught of the syphilis pandemic that started in the late fifteenth century established this devastating infectious disease as one of the most feared in human history1 . Surprisingly, despite the availability of effective antibiotic treatment since the mid-twentieth century, this bacterial infection, which is caused by Treponema pallidum subsp. pallidum (TPA), has been re-emerging globally in the last few decades with an estimated 10.6 million cases in 2008 (ref. 2). Although resistance to penicillin has not yet been identified, an increasing number of strains fail to respond to the secondline antibiotic azithromycin3. Little is known about the genetic patterns in current infec…

Effect of temperature on the prevalence of Saccharomyces non-cerevisiae species against a S. cerevisiae wine strain in wine fermentation: competition…

2017

Saccharomyces cerevisiae is the main microorganism responsible for the fermentation of wine. Nevertheless, in the last years wineries are facing new challenges due to current market demands and climate change effects on the wine quality. New yeast starters formed by non-conventional Saccharomyces species (such as S. uvarum or S. kudriavzevii) or their hybrids (S. cerevisiae x S. uvarum and S. cerevisiae x S. kudriavzevii) can contribute to solve some of these challenges. They exhibit good fermentative capabilities at low temperatures, producing wines with lower alcohol and higher glycerol amounts. However, S. cerevisiae can competitively displace other yeast species from wine fermentations,…

2017

Previous studies reported that the use of Metschnikowia pulcherrima in sequential culture fermentation with Saccharomyces cerevisiae mainly induced a reduction of volatile acidity in wine. The impact of the presence of this yeast on the metabolic pathway involved in pyruvate dehydrogenase (PDH) bypass and glycerol production in S. cerevisiae has never been investigated. In this work, we compared acetic acid and glycerol production kinetics between pure S. cerevisiae culture and its sequential culture with M. pulcherrima during alcoholic fermentation. In parallel, the expression levels of the principal genes involved in PDH bypass and glyceropyruvic fermentation in S. cerevisiae were investi…

Persistence of Two Non-Saccharomyces Yeasts (Hanseniaspora and Starmerella) in the Cellar

2016

International audience; Different genera and/or species of yeasts present on grape berries, in musts and wines are widely described. Nevertheless, the community of non-Saccharomyces yeasts present in the cellar is still given little attention. Thus it is not known if the cellar is a real ecological niche for these yeasts or if it is merely a transient habitat for populations brought in by grape berries during the winemaking period. This study focused on three species of non-Saccharomyces yeasts commonly encountered during vinification: Starmerella bacillaris (synonymy with Candida zemplinina), Hanseniaspora guilliermondii and Hanseniaspora uvarum. More than 1200 isolates were identified at …

Draft genome sequence and biofilm production of a carbapenemase-producing Klebsiella pneumoniae (KpR405) sequence type 405 strain isolated in Italy

2021

Rapid identification and characterization of multidrug-resistant Klebsiella pneumoniae strains is essential to diagnose severe infections in patients. In clinical routine practice, K. pneumoniae is frequently identified and characterized for outbreak investigation. Pulsed-field gel electrophoresis or multilocus sequence typing could be used, but, unfortunately, these methods are time-consuming, laborious, expensive, and do not provide any information about the presence of resistance and virulence genes. In recent years, the decreasing cost of next-generation sequencing and its easy use have led to it being considered a useful method, not only for outbreak surveillance but also for rapid ide…

Molecular epidemiology and drug-resistance mechanisms in carbapenem-resistant Klebsiella pneumoniae isolated in patients from a tertiary hospital in …

2020

Abstract Objectives The aim of this study has been to characterize carbapenem-resistant Klebsiella pneumoniae isolates and to determine the resistance mechanisms involved, the clonal relationship between strains and clinical and demographical data of the infected patients. Methods Clinical and demographical data from patients were collected and statistically analysed. Antimicrobial susceptibility testing was performed and resistance genes were detected both phenotypically and genotypically. Conjugation assays were performed to show horizontal transferability of resistance genes. Clonal relationship was also studied. Next-generation sequencing (NGS) was performed to obtain information regard…

The Use of Mixed Populations of Saccharomyces cerevisiae and S. kudriavzevii to Reduce Ethanol Content in Wine: Limited Aeration, Inoculum Proportion…

2017

Saccharomyces cerevisiae is the most widespread microorganism responsible for wine alcoholic fermentation. Nevertheless, the wine industry is currently facing new challenges, some of them associate with climate change, which have a negative effect on ethanol content and wine quality. Numerous and varied strategies have been carried out to overcome these concerns. From a biotechnological point of view, the use of alternative non-Saccharomyces yeasts, yielding lower ethanol concentrations and sometimes giving rise to new and interesting aroma, is one of the trendiest approaches. However, S. cerevisiae usually outcompetes other Saccharomyces species due to its better adaptation to the fermenta…

Editorial for Special Issue “Yeast in Winemaking”

2021

Yeast in winemaking was first studied for its role in alcoholic fermentation, and has led to the publication of a huge amount of scientific articles [...]

Direct and Rapid Detection and Quantification of Oenococcus oeni Cells in Wine by Cells-LAMP and Cells-qLAMP

2018

Fast detection and enumeration of Oenococcus oeni in winemaking are necessary to determine whether malolactic fermentation (MLF) is likely to be performed or not and to decide if the use of a commercial starter is needed. In other wines, however, performing MLF can be detrimental for wine and should be avoided. The traditional identification and quantification of this bacteria using culture-dependent techniques in wine-related matrices require up to 14 days to yield results, which can be a very long time to perform possible enological operations. Loop-mediated isothermal amplification (LAMP) is a novel culture-independent technique that amplifies nucleic acid sequences under isothermal cond…