scholarly journals The addition of wine yeast Starmerella bacillaris to grape skin surface influences must fermentation and glycerol production

OENO One ◽  
2021 ◽  
Vol 55 (2) ◽  
pp. 47-55
Author(s):  
Chiara Nadai ◽  
Alessio Giacomini ◽  
Viviana Corich
Keyword(s):  
Antifungal Activity ◽  
Grey Mould ◽  
Wine Yeast ◽  
Skin Surface ◽  
Inoculum Size ◽  
Wine Quality ◽  
Grape Skin ◽  
Reference Concentration ◽  
Starting Point ◽  
High Concentrations

Starmerella bacillaris is a non-Saccharomyces yeast recently proposed for grape fermentation in association with Saccharomyces cerevisiae. Due to its high glycerol and moderate volatile acidity production this yeast can contribute to improving wine quality. Some strains have been demonstrated to exhibit antifungal activity against grey mould on grape, which is caused by Botrytis cinerea. The simultaneous presence of these traits in S. bacillaris is of great interest. Indeed, this yeast can be potentially used as a biocontrol agent in vineyards. Research on the ability of S. bacillaris to survive or, even to grow on the surface of grapes is a starting point in the evaluatation of its potential use in vineyards. The preliminary results of our study showed that when applied to the grape surface under laboratory condictions, inoculum sized S. bacillaris with antifungal activity developed and lasted for at least 6 days in high concentrations. In addition, it positively influenced the fermentation process by producing high concentrations of glycerol (average value 4.89 ± 0.47 g/L). Interestingly, a positive effect on wine quality was also observed when the inoculum size was 10 times higher or lower than the reference concentration. When sprayed on the vines in the vineyard and present on the grape skin surface after harvest, S. bacillaris cells can start alcoholic fermentation.

Identification of N-Substituted Triazolo-azetidines as Novel Antibacterials using pDualrep2 HTS Platform

2019 ◽  
Vol 22 (5) ◽  
pp. 346-354
Author(s):  
Yan A. Ivanenkov ◽  
Renat S. Yamidanov ◽  
Ilya A. Osterman ◽  
Petr V. Sergiev ◽  
Vladimir A. Aladinskiy ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Large Scale ◽  
Underlying Mechanism ◽  
Luciferase Assay ◽  
Reporter System ◽  
E Coli ◽  
Starting Point ◽  
High Concentrations ◽  
Mic Value

Aim and Objective: Antibiotic resistance is a serious constraint to the development of new effective antibacterials. Therefore, the discovery of the new antibacterials remains one of the main challenges in modern medicinal chemistry. This study was undertaken to identify novel molecules with antibacterial activity. Materials and Methods: Using our unique double-reporter system, in-house large-scale HTS campaign was conducted for the identification of antibacterial potency of small-molecule compounds. The construction allows us to visually assess the underlying mechanism of action. After the initial HTS and rescreen procedure, luciferase assay, C14-test, determination of MIC value and PrestoBlue test were carried out. Results: HTS rounds and rescreen campaign have revealed the antibacterial activity of a series of Nsubstituted triazolo-azetidines and their isosteric derivatives that has not been reported previously. Primary hit-molecule demonstrated a MIC value of 12.5 µg/mL against E. coli Δ tolC with signs of translation blockage and no SOS-response. Translation inhibition (26%, luciferase assay) was achieved at high concentrations up to 160 µg/mL, while no activity was found using C14-test. The compound did not demonstrate cytotoxicity in the PrestoBlue assay against a panel of eukaryotic cells. Within a series of direct structural analogues bearing the same or bioisosteric scaffold, compound 2 was found to have an improved antibacterial potency (MIC=6.25 µg/mL) close to Erythromycin (MIC=2.5-5 µg/mL) against the same strain. In contrast to the parent hit, this compound was more active and selective, and provided a robust IP position. Conclusion: N-substituted triazolo-azetidine scaffold may be used as a versatile starting point for the development of novel active and selective antibacterial compounds.

Antifungal Activity Directed Toward the Cell Wall by 2-Cyclohexylidenhydrazo- 4-Phenyl-Thiazole Against Candida albicans

2019 ◽  
Vol 19 (4) ◽  
pp. 428-438 ◽  
Author(s):  
Nívea P. de Sá ◽  
Ana P. Pôssa ◽  
Pilar Perez ◽  
Jaqueline M.S. Ferreira ◽  
Nayara C. Fonseca ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Antifungal Activity ◽  
Mammalian Cells ◽  
C Elegans ◽  
Buccal Epithelial Cells ◽  
Mutant Strains ◽  
Low Toxicity ◽  
High Concentrations ◽  
Mic Value

<p>Background: The increasing incidence of invasive forms of candidiasis and resistance to antifungal therapy leads us to seek new and more effective antifungal compounds. </P><P> Objective: To investigate the antifungal activity and toxicity as well as to evaluate the potential targets of 2- cyclohexylidenhydrazo-4-phenyl-thiazole (CPT) in Candida albicans. </P><P> Methods: The antifungal activity of CPT against the survival of C. albicans was investigated in Caenorhabditis elegans. Additionally, we determined the effect of CPT on the inhibition of C. albicans adhesion capacity to buccal epithelial cells (BECs), the toxicity of CPT in mammalian cells, and the potential targets of CPT in C. albicans. </P><P> Results: CPT exhibited a minimum inhibitory concentration (MIC) value of 0.4-1.9 µg/mL. Furthermore, CPT at high concentrations (>60 x MIC) showed no or low toxicity in HepG2 cells and <1% haemolysis in human erythrocytes. In addition, CPT decreased the adhesion capacity of yeasts to the BECs and prolonged the survival of C. elegans infected with C. albicans. Analysis of CPT-treated cells showed that their cell wall was thinner than that of untreated cells, especially the glucan layer. We found that there was a significantly lower quantity of 1,3-β-D-glucan present in CPT-treated cells than that in untreated cells. Assays performed on several mutant strains showed that the MIC value of CPT was high for its antifungal activity on yeasts with defective 1,3-β-glucan synthase. </P><P> Conclusion: In conclusion, CPT appears to target the cell wall of C. albicans, exhibits low toxicity in mammalian cells, and prolongs the survival of C. elegans infected with C. albicans.</p>

scholarly journals Biocatalytic Transformation of 5-Hydroxymethylfurfural into 2,5-di(hydroxymethyl)furan by a Newly Isolated Fusarium striatum Strain

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 216
Author(s):  
Alberto Millán ◽  
Núria Sala ◽  
Mercè Torres ◽  
Ramon Canela-Garayoa
Keyword(s):  
Fusarium Species ◽  
Inoculum Size ◽  
High Recovery ◽  
23 Factorial Design ◽  
Organic Solvent Extraction ◽  
Working Volume ◽  
The Media ◽  
Substrate Feeding ◽  
High Concentrations ◽  
Reaction Media

The compound 2,5-di(hydroxymethyl)furan (DHMF) is a high-value chemical block that can be synthesized from 5-hydroxymethylfurfural (HMF), a platform chemical that results from the dehydration of biomass-derived carbohydrates. In this work, the HMF biotransformation capability of different Fusarium species was evaluated, and F. striatum was selected to produce DHMF. The effects of the inoculum size, glucose concentration and pH of the media over DHMF production were evaluated by a 23 factorial design. A substrate feeding approach was found suitable to overcome the toxicity effect of HMF towards the cells when added at high concentrations (>75 mM). The process was successfully scaled-up at bioreactor scale (1.3 L working volume) with excellent DHMF production yields (95%) and selectivity (98%). DHMF was purified from the reaction media with high recovery and purity by organic solvent extraction with ethyl acetate.

scholarly journals Isolated domains of recombinant human apo-metallothionein 1A are folded at neutral pH: a denaturant and heat-induced unfolding study using ESI-MS

2018 ◽  
Vol 38 (4) ◽  
Author(s):  
Gordon W. Irvine ◽  
Natalie Korkola ◽  
Martin J. Stillman
Keyword(s):  
Critical Role ◽  
Cysteine Residues ◽  
Small Molecular Weight ◽  
Esi Ms ◽  
Neutral Ph ◽  
Induced Folding ◽  
Starting Point ◽  
High Metal ◽  
High Concentrations ◽  
Product Species

Metallothioneins (MTs) are characterized by their high metal loading capacity, small molecular weight, and abundant cysteine residues. It has long been thought that metal-free, or apo-MT peptides were unstructured and only adopted as a distinct conformation upon forming the metal clusters, described as metal-induced folding. More recent studies have suggested that the presence of a globular, yet loosely defined structure actually exists that can be disrupted or unfolded. Residue modification and ion-mobility ESI (IM-ESI)-MS have been used to examine this unusual unfolding process. The structure of apo-MT plays a critical role as the starting point in the flexible metalation pathways that can accommodate numerous soft metals. ESI-MS measurements of the product species formed following the cysteine alkylation of the isolated domain fragments of recombinant human apo-MT 1A with n-ethylmaleimide (NEM) were used in the present study to monitor the denaturant- and heat-induced unfolding at physiological pH. The results indicate that these apo-MT fragments adopt distinct structures at neutral pH that react co-operatively with NEM when folded and non-cooperatively when heated or exposed to high concentrations of the denaturant guanidinium chloride (GdmCl). From these studies, we can conclude that at neutral pH, the domain fragments are folded into globular structures where some of the free cysteine residues are buried within the core and are stabilized by hydrogen bonds. Metalation therefore, must take place from the folded conformation.

Night-time chemistry of biomass burning plumes in urban areas: A dual mobile chamber study

2021 ◽  
Author(s):  
Spiro Jorga ◽  
Kalliopi Florou ◽  
Christos Kaltsonoudis ◽  
John Kodros ◽  
Christina Vasilakopoulou ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Urban Areas ◽  
Mass Spectra ◽  
Prescribed Burning ◽  
Organic Aerosol ◽  
Photochemical Activity ◽  
Organic Nitrate ◽  
Night Time ◽  
Starting Point ◽  
High Concentrations

&lt;p&gt;Biomass burning including residential heating, agricultural fires, prescribed burning, and wildfires is a major source of gaseous and particulate pollutants in the atmosphere. Although, important changes in the size distributions and the chemical composition of the biomass burning aerosol during daytime chemistry have been observed, the corresponding changes at nighttime or in winter where photochemistry is slow, have received relatively little attention. In this study, we tested the hypothesis that nightime chemistry in biomass burning plumes can be rapid in urban areas using a dual smog chamber system.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;Ambient urban air during winter nighttime periods with high concentrations of ambient biomass burning organic aerosol is used as the starting point. Ozone was added in the perturbed chamber to simulate mixing with background air (and subsequent NO&lt;sub&gt;3&lt;/sub&gt; production and aging) while the second chamber was used as a reference. Following the injection of ozone rapid organic aerosol (OA) formation was observed in all experiments leading to increases of the OA concentration by 20-70%. The oxygen to carbon ratio of the OA increased by 50% on average and the mass spectra of the produced OA was quite similar to that of the oxidized OA mass spectra reported during winter in urban areas. Good correlation was also observed with the produced mass spectra from nocturnal aging of laboratory biomass burning emissions showing the strong contribution of biomass burning emissions in the SOA formation during cold nights with high biomass burning activities. Concentrations of NO&lt;sub&gt;3&lt;/sub&gt; radicals as high as 25 ppt were measured in the perturbed chamber with an accompanying production of 0.2-1.2 &amp;#956;g m&lt;sup&gt;-3&lt;/sup&gt; of organic nitrate. These results strongly indicate that the OA in biomass burning plumes can evolve rapidly even during wintertime periods with low photochemical activity.&lt;/p&gt;

scholarly journals Antifungal Activity and Fourier Transform Infrared Spectrometric Characterization of Aqueous Extracts of Acacia senegal and Acacia tortilis on Phytopathogenic Fungi

2019 ◽  
pp. 1-11
Author(s):  
Al-Otibi Fatimah
Keyword(s):  
Fourier Transform ◽  
Antifungal Activity ◽  
Functional Groups ◽  
Aqueous Extract ◽  
Phytopathogenic Fungi ◽  
Aqueous Extracts ◽  
Acacia Tortilis ◽  
Acacia Senegal ◽  
High Concentrations ◽  
Scanning Electron

Objective: To evaluate the in vitro antifungal activity of aqueous extracts of Acacia senegal (A. senegal) and Acacia tortilis (A. tortilis) against three phytopathogenic fungi (viz., Alternaria alternata [A. alternata], Helminthosporium rostratum [H. rostratum] and Fusarium solani [F. solani]). Methods: Crude aqueous extracts of A. senegal and A. tortilis at 1%, 2.5% and 5% concentrations were used for screening. Antifungal activities of the extracts were evaluated against three phytopathogenic fungal strains (A. alternata, H. rostratum and F. solani) by poisoned food technique. Scanning electron microscopy (SEM) of the treated and untreated mycelia was employed to analyze the ultrastructural changes and Fourier-transform infrared (FTIR) spectrometry analysis was performed to identify important functional groups. Results: Aqueous extract of A. tortilis at high concentrations exhibited moderate inhibitory activity against the selected fungal strains. The aqueous extract of A. senegal showed no effect on A. alternata, while exhibited very mild activity against H. rostratum and F. solani at high concentrations (2.5% and 5%). Scanning electron microphotographs of the untreated fungal cells showed no structural changes (well‒defined mycelium and conidia without any distortion), whereas the treated cells showed structural distortions, twisted and wrecked mycelia and showed the presence of vesicles on the surface. FTIR analysis showed the presence of important functional groups such as alcohols, carboxylic acids and aromatic compounds. Conclusion: Results from this study indicate that the aqueous extracts of both A. senegal and A. tortilis have the potential to be used as natural fungicidal agents in the management of diseases caused by plant pathogenic fungi.

scholarly journals Prediction of Botrytis cinerea Risk in Vineyards Based on Weather Indicators

2020 ◽  
Vol 77 (2) ◽  
pp. 58
Author(s):  
Liliana PIRCALABU ◽  
Elena BRINDUSE ◽  
Marian ION
Keyword(s):  
High Risk ◽  
Botrytis Cinerea ◽  
Predictive Models ◽  
Meteorological Data ◽  
Grey Mould ◽  
Low Risk ◽  
Wine Quality ◽  
The Hours ◽  
Medium Risk ◽  
Positive Correlations

Botrytis cinerea causes grey mould, a major disease occurring in vineyards worldwide, resulting in loss of grape production and wine quality. Predictive models of favorability of Botrytis cinerea were used. Therefore, a series of meteorological data from 2010 to 2019 was used. The results showed that the frequency of years with low risk of Botrytis cinerea was 10%, medium risk 10%, high risk 80%. The disease can drastically reduce both yield and wine quality (Ribereau Gayon et al., 1980). The harvest years 2010, 2011, 2012, 2013 and 2014, favored the manifestation of an attack degree of 62.9% (2012) and 34.2% (2013). Positive correlations were observed in the case of Broome index and Bacchus index with the duration of sunlight (r2 = 0.935), respectively (r2 = 0.944) and the sum of the hours of moisture on the leaves (r2 = 0.833, r2 = 0.848). Based on the results a model for prediction of Botrytis cinerea risk will be developed.

scholarly journals Wine Yeast Terroir: Separating the Wheat from the Chaff—for an Open Debate

2020 ◽  
Vol 8 (5) ◽  
pp. 787 ◽  
Author(s):  
Hervé Alexandre
Keyword(s):  
Microbial Communities ◽  
High Throughput Sequencing ◽  
Abiotic Factors ◽  
Soil Microbial Communities ◽  
Consumer Preference ◽  
Wine Yeast ◽  
Wine Quality ◽  
Critical Feature ◽  
Wine Production ◽  
Sequencing Technologies

Wine terroir is characterized by a specific taste and style influenced by the cultivar of the fermented grapes, geographical factors such as the vineyard, mesoclimate, topoclimate, and microclimate, soil geology and pedology, and the agronomic approach used. These characteristics together define the concept of “terroir”. Thus, regional distinctive flavors in wine have been the subject of many studies aimed at better understanding the link between the wine and the vineyard. Indeed, the identification of key environmental elements involved in the regional variation of grape and wine quality characteristics is a critical feature for improving wine production in terms of consumer preference and economic appreciation. Many studies have demonstrated the role of abiotic factors in grape composition and consequently in wine style. Biotic factors are also involved such as grape microbial communities. However, the occurrence and effects of region-specific microbiota in defining wine characteristics are more controversial issues. Indeed, several studies using high throughput sequencing technologies have made it possible to describe microbial communities and revealed a link between grape must and soil microbial communities, and the geography of the territory. Based on these observations, the concept of “microbial terroir” emerged. However, this concept has been subject to contradictory studies. The aim of this opinion article is to take a step back and examine in perspective the concept of microbial terroir, by comparing numerous data from different studies and providing arguments in favor of or against this concept to stimulate discussion and point out that experimental research is still needed to study the contribution of this assembly of microorganisms to the final product and to support or refute the concept.

Determination of Positional Skin-Surface Pressures in Premature Infants

2004 ◽  
Vol 23 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Lenora Marcellus
Keyword(s):  
Premature Infants ◽  
Repeated Measures ◽  
Skin Surface ◽  
Repeated Measures Design ◽  
Pressure Distributions ◽  
Body Tissues ◽  
Starting Point ◽  
Postconceptional Age ◽  
Maximal Pressure ◽  
The Mean

Purpose: To describe the skin-surface pressure distributions and points of maximal pressure that are generated by healthy premature infants in the supine, prone, and right side–lying positions.Design: A descriptive, repeated-measures design.Sample: Four medically stable premature infants of 34 weeks postconceptional age. The mean weight was 2,180 gm, and the mean age was 24.5 days.Results: Similar regions of increased skin-surface pressures were identified for the four infants. Within areas of peak pressure, some sensor cells reached 28–32 millimeters of mercury, which is considered to be the critical compressive pressure for obstruction of nutritive flow to the underlying body tissues. These descriptive results may be a starting point for development of research studies to determine positioning strategies to optimize the skin integrity of premature infants while minimizing unnecessary handling.

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