This study aimed to analyse the behaviour of volatile compounds during double batch cider distillation to produce Calvados. More precisely, it allowed to analyse the influence of the recycling of the ...separated fractions to manage the cuts according to the quality target. 700 L of cider were distilled with a 115 L Charentais still and 28 congeners were quantified into 65 samples from nine cider and two brouillis distillations. Most of alcohols were totally recovered into the heart of the second brouillis distillation, except 2-phenylethanol recovered at 5.4% because of its low volatility. For the same reason, esters as 2-phenylacetate, ethyl 2-hydroxypropanoate and diethyl butanedioate were significantly lost in the residues. Stopping distillations beyond 2 %v/v would increase their recovery but at an increasing cost. Other compounds are strongly concentrated in the head fractions. Among them, some such as ethyl acetate and acetaldehyde have negative impact on quality, while others such as ethyl decanoate and ethyl hexanoate bring floral notes. As these positive compounds are less concentrated in the head fraction of brouillis distillation than cider distillation, it is best, if negative compounds must be eliminated, to choose to extract head from brouillis distillation. Other possibility is to limit production of negative compounds.
•The volatile compounds behaviour was demonstrated during recycling in double batch distillation.•A mass balance was systematically calculated to check the measurements coherence.•Knowledge of the compounds' behaviour helps to decide the definitive extraction of heads or tails.
Bacterial and fungal population dynamics in cider for distillation have so far been explored by culture-dependant methods. Cider for distillation can be produced by the spontaneous fermentation of ...apples that do not undergo any intervention during the process. In this study, cider microbiomes extracted from six tanks containing ciders for distillation from four producers in Normandy were characterized at three main stages of the fermentation process: fermentation Initiation (I), end of the alcoholic Fermentation (F) and end of the Maturation period (M). Cider samples were subjected to Illumina MiSeq sequencing (rRNA 16S V1-V3 and ITS1 region targeting) to determine bacterial and fungal communities. Yeasts (YGC), Zymomonas (mZPP) and lactic acid bacteria selective media (mMRS, mMLO, mPSM) were also used to collect 807 isolates. Alcoholic levels, glycerol, sugar content (glucose, fructose and sucrose), pH, total and volatile acidity, nitrogen, malic and lactic acid contents were determined at all sampling points. Alpha diversity indexes show significant differences (p < 0.05) in microbial populations between I, F and M. Fungal communities were characterized by microorganisms from the environment and phytopathogens at I followed by the association of yearsts with alcoholic fermentation like Saccharomyces and non-Saccharomyces yeasts (Hanseniaspora, Candida). A maturation period for cider leads to an increase of the Dekkera/Brettanomyces population, which is responsible for off-flavors in cider for all producers. Among bacterial communities, the genera community associated to malolactic fermentation (Lactobacillus sp., Leuconostoc sp., Oenococcus sp.) was the most abundant at F and M. Acetic acid bacteria such as Acetobacter sp., Komagataeibacter sp. and Gluconobacter sp. were also detected during the process. Significant differences (p < 0.05) were found in fungal and bacterial populations between the four producers and during the fermentation process. The development of microorganisms associated with cider spoilage such as Zymomonas mobilis, Lactobacillus collinoides or Brettanomyces/Dekkera sp. was anticipated by a metagenomic approach. The monitoring of microbial diversity via high throughput sequencing combined with physical-chemical analysis is an interesting approach to improve the fermentation performance of cider for distillation and therefore, the quality of Calvados.
•Six tanks of ciders for distillation from four producers were monitored•Metagenomics revealed 40 and 48 bacterial and fungal genera in cider for distillation•Each producer has a specific microbial ecosystem composition•Malolactic conversion, if present, occurred simultaneously with alcoholic fermentation•Zymomonas and Dekkera spoilage were anticipated by metagenomic analysis
Mycophenolic acid (MPA) is the fungal secondary metabolite displaying several biological properties. Up to now, screening of fungal strains producing MPA has mainly been the result of the search of ...this molecule in their culture medium by chemical methods. Here we developed a molecular approach by targeting the expression level of the MpaC gene encoding the polyketide synthase, one of the key enzymes involved in the MPA synthesis. Thirty xerophilic Aspergillus strains were identified using the RNA polymerase II subunit and the β-tubulin genes. Seven Aspergillus species were evidenced. The expression level of the MpaC gene was quantified and compared to the MPA production rate. Only Aspergillus pseudoglaucus and all the eight strains of this species produced MPA. While the MpaC gene was not expressed or weakly expressed in the MPA non-producing strains, all the A. pseudoglaucus strains presented a high level of expression of this gene. The highest expression level of the MpaC gene among the MPA non-producing strains was significantly lower than the lowest expression level of this gene in the MPA producing strains. To our knowledge, this is the first study that demonstrates the effectiveness of molecular approach for the screening of MPA-producing species.
•We investigated the mycophenolic acid (MPA) production in Aspergillus species.•We found that only and all the Aspergillus pseudoglaucus strains produced MPA.•The MPA production coincided with a high expression of the polyketide synthase gene.•This suggests the efficiency of molecular approach to screen MPA-producing species.
Different
Lactobacillus collinoides and
Brettanomyces/Dekkera anomala cider strains were studied for their ability to produce volatile phenols in synthetic medium. All strains were able to produce ...4-ethylcatechol (4-EC), 4-ethylphenol (4-EP) and 4-ethylguaiacol (4-EG) from caffeic,
p-coumaric and ferulic acids, respectively. Interestingly,
D. anomala and
L. collinoides were also able to produce 4-EC, 4-EP and 4-EG in cider conditions. The quantities of ethylphenols produced by these two species were similar in both tested ciders. The impact of precursor quantities was studied and it showed that the addition of caffeic and
p-coumaric acids in ciders allowed for higher 4-EC and 4-EP production by
D. anomala and
L. collinoides. In parallel,
D. anomala and
L. collinoides strains were isolated from a phenolic off-flavour defective bottled cider after ethylphenol production hence confirming the implication of these two species in this cider spoilage. Finally, detection thresholds of the main ethylphenols were determined in ciders by orthonasal and retronasal sampling. The 4-EC and 4-EP detection thresholds (close to 20–25
mg/l and 1.5–2.0
mg/l, respectively) were matrix dependant.
► All the tested
L. collinoides and
D. anomala cider strains were able to produce ethylphenols. ► Interestingly,
D. anomala and
L. collinoides were able to produce 4-EC, 4-EP and 4-EG in real cider conditions. ► Impact of precursor quantities to volatile phenol production was studied in ciders.
► D. anomala and
L. collinoides strains were isolated from a bottled cider during ethylphenol production. ► Detection thresholds of the main ethylphenols were determined in ciders by two different methods.
Indoor air quality in health care facilities is a major public health concern, particularly for immunocompromised patients who may be exposed to microbiological contaminants such as molds, ...mycotoxins, endotoxins, and (1,3)-ß-D-glucans. Over 2 years, bioaerosols were collected on a monthly basis in a cancer treatment center (Centre F. Baclesse, Normandy, France), characterized from areas where there was no any particular air treatment. Results showed the complexity of mycoflora in bioaerosols with more than 100 fungal species identified. A list of major strains in hospital environments could be put forward due to the frequency, the concentration level, and/or the capacity to produce mycotoxins in vitro:
Aspergillus fumigatus
,
Aspergillus melleus
,
Aspergillus niger
,
Aspergillus versicolor
,
Cladosporium herbarum
,
Purpureocillium lilacinum
, and
Penicillium brevicompactum
. The mean levels of viable airborne fungal particles were less than 30.530 CFU per m
3
of air and were correlated to the total number of 0.30 to 20 μm particles. Seasonal variations were observed with fungal particle peaks during the summer and autumn. Statistical analysis showed that airborne fungal particle levels depended on the relative humidity level which could be a useful indicator of fungal contamination. Finally, the exposure to airborne mycotoxins was very low (only 3 positive samples), and no mutagenic activity was found in bioaerosols. Nevertheless, some fungal strains such as
Aspergillus versicolor
or
Penicillium brevicompactum
showed toxigenic potential in vitro.
1. Pig synovial fibroblasts in culture were studied to determine if they were an easily reproducible model system for studying the actions of cytokines and growth factors on human synovial cells. The ...biochemical analyses were conducted by activity assays, enzymography and Northern blot. 2. Human recombinant interleukin-1 alpha, basic fibroblast growth factor and transforming growth factor-beta 1 were studied in combinations because of their known involvement in controlling tissue remodelling. 3. The response of pig fibroblasts to these agents, in terms of the expression of matrix metalloproteinases (collagenase, gelatinase and stromelysin) and their inhibitors (TIMPs), show that they behave similarly enough to human cells for use when supplies of human primary cells are unavailable.
In this trial involving women undergoing cesarean delivery (all of whom received prophylactic uterotonic medication), tranexamic acid treatment resulted in a significantly lower incidence of ...estimated blood loss greater than 1000 ml or red-cell transfusion by day 2 than placebo, but it did not reduce the risk of hemorrhage-related secondary clinical outcomes.
The robust detection of disease-associated splice events from RNAseq data is challenging due to the potential confounding effect of gene expression levels and the often limited number of patients ...with relevant RNAseq data. Here we present a novel statistical approach to splicing outlier detection and differential splicing analysis. Our approach tests for differences in the percentages of sequence reads representing local splice events. We describe a software package called Bisbee which can predict the protein-level effect of splice alterations, a key feature lacking in many other splicing analysis resources. We leverage Bisbee's prediction of protein level effects as a benchmark of its capabilities using matched sets of RNAseq and mass spectrometry data from normal tissues. Bisbee exhibits improved sensitivity and specificity over existing approaches and can be used to identify tissue-specific splice variants whose protein-level expression can be confirmed by mass spectrometry. We also applied Bisbee to assess evidence for a pathogenic splicing variant contributing to a rare disease and to identify tumor-specific splice isoforms associated with an oncogenic mutation. Bisbee was able to rediscover previously validated results in both of these cases and also identify common tumor-associated splice isoforms replicated in two independent melanoma datasets.
Summary Background Rejection of allografts has always been the major obstacle to transplantation success. We aimed to improve characterisation of different kidney-allograft rejection phenotypes, ...identify how each one is associated with anti-HLA antibodies, and investigate their distinct prognoses. Methods Patients who underwent ABO-compatible kidney transplantations in Necker Hospital and Saint-Louis Hospital (Paris, France) between Jan 1, 1998, and Dec 31, 2008, were included in our population-based study. We assessed patients who provided biopsy samples for acute allograft rejection, which was defined as the association of deterioration in function and histopathological lesions. The main outcome was kidney allograft loss—ie, return to dialysis. To investigate distinct rejection patterns, we retrospectively assessed rejection episodes with review of graft histology, C4d in allograft biopsies, and donor-specific anti-HLA antibodies. Findings 2079 patients were included in the main analyses, of whom 302 (15%) had acute biopsy-proven rejection. We identified four distinct patterns of kidney allograft rejection: T cell-mediated vascular rejection (26 patients 9%), antibody-mediated vascular rejection (64 21%), T cell-mediated rejection without vasculitis (139 46%), and antibody-mediated rejection without vasculitis (73 24%). Risk of graft loss was 9·07 times (95 CI 3·62–19·7) higher in antibody-mediated vascular rejection than in T cell-mediated rejection without vasculitis (p<0·0001), compared with an increase of 2·93 times (1·1–7·9; P=0·0237) in antibody-mediated rejection without vasculitis and no significant rise in T cell-mediated vascular rejection (hazard ratio HR 1·5, 95% CI 0·33–7·6; p=0·60). Interpretation We have identified a type of kidney rejection not presently included in classifications: antibody-mediated vascular rejection. Recognition of this distinct phenotype could lead to the development of new treatment strategies that could salvage many kidney allografts. Funding None.
Primary ciliary dyskinesia (PCD) is a genetic disorder in which impaired ciliary function leads to chronic airway disease. Exome sequencing of a PCD subject identified an apparent homozygous ...frameshift variant, c.887_890delTAAG (p.Val296Glyfs∗13), in exon 5; this frameshift introduces a stop codon in amino acid 308 of the growth arrest-specific protein 2-like 2 (GAS2L2). Further genetic screening of unrelated PCD subjects identified a second proband with a compound heterozygous variant carrying the identical frameshift variant and a large deletion (c.867_∗343+1207del; p.?) starting in exon 5. Both individuals had clinical features of PCD but normal ciliary axoneme structure. In this research, using human nasal cells, mouse models, and X.laevis embryos, we show that GAS2L2 is abundant at the apical surface of ciliated cells, where it localizes with basal bodies, basal feet, rootlets, and actin filaments. Cultured GAS2L2-deficient nasal epithelial cells from one of the affected individuals showed defects in ciliary orientation and had an asynchronous and hyperkinetic (GAS2L2-deficient = 19.8 Hz versus control = 15.8 Hz) ciliary-beat pattern. These results were recapitulated in Gas2l2−/− mouse tracheal epithelial cell (mTEC) cultures and in X. laevis embryos treated with Gas2l2 morpholinos. In mice, the absence of Gas2l2 caused neonatal death, and the conditional deletion of Gas2l2 impaired mucociliary clearance (MCC) and led to mucus accumulation. These results show that a pathogenic variant in GAS2L2 causes a genetic defect in ciliary orientation and impairs MCC and results in PCD.
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