Vitalized yeast with high ethanol productivity

RSC Advances ◽  
2014 ◽  
Vol 4 (94) ◽  
pp. 52299-52306 ◽  
Author(s):  
Xiumei Liu ◽  
Wenjuan Xu ◽  
Chao Zhang ◽  
Peifang Yan ◽  
Songyan Jia ◽  
...  
Keyword(s):  
Water Soluble ◽  
Ethanol Productivity ◽  
Yeast Cells ◽  
High Ethanol

Yeast cells exo-protected by water soluble PEGs are tolerant to higher ethanol concentrations, and offer high ethanol productivity.

scholarly journals THE ALTERATION OF INTRACELLULAR ENZYMES

1954 ◽  
Vol 38 (2) ◽  
pp. 197-211 ◽  
Author(s):  
J. Gordin Kaplan ◽  
Keyword(s):  
Critical Concentration ◽  
Micelle Formation ◽  
Water Soluble ◽  
Yeast Cells ◽  
Surface Activities ◽  
Irreversible Inhibition ◽  
Surface Active Agents ◽  
Maximal Activation ◽  
Surface Active ◽  
Methylene Group

1. The ability of homologous series of alcohols, ketones, and aldehydes to cause alteration of intracellular catalase increases approximately threefold for each methylene group added, thus following Traube's rule. Equiactive concentrations of alcohols (methanol to octanol) varied over a 4,000-fold range, yet the average corresponding surface tension was 42 ± 2 dynes/cm., that for ketones 43 ± 2, and for aldehydes (above C1) 41 ± 3. 2. Above C8 the altering activity of alcohols ceased to follow Traube's rule, and at C18 was nil. Yet the surface activities of alcohols from nonanol to dodecanol did follow Traube's rule. These two facts show that the interface which is being affected by these agents is not the cell surface, for if it were, altering activity should not fall off between C9 and C12 where surface activity is undiminished; they show also that micelle formation by short range association of hydrocarbon "tails," usually invoked to explain decrease in biological activity of compounds above C8, is not responsible for this effect in these experiments, in which permeability of the cell membrane probably is involved. 3. The most soluble alcohols and aldehydes (alcohols C1 to C8; aldehydes C1, C2), but not ketones, cause, above optimal concentration, an irreversible inhibition of yeast catalase. 4. The critical concentration of altering agent (i.e., that concentration just sufficient to cause doubling of the catalase activity of the yeast suspension) was independent of the concentration of the yeast cells. 5. Viability studies show that the number of yeast cells killed by the altering agents was not related to the degree of activation of the catalase produced. While all the cells were invariably killed by concentrations of altering agent which produced complete activation, all the cells had been killed by concentrations which were insufficient to cause more than 50 per cent maximal activation. Further, the evidence suggested that the catalase may be partially activated by concentrations of altering agent which cause no decrease in viability at all. Hence alteration, unlike death, may not be all-or-none per cell. 6. The fact that the biological criterion being examined was the activation of a water-soluble enzyme rules out the possibility that the reason for the logarithmic increase in altering activity with chain length was increase in concentration of the altering agent in some intracellular fat phase. It is concluded that these surface-active agents cause enzyme alteration by becoming adsorbed at some intracellular interface and thus causing, directly or indirectly, the modification of catalase properties. 7. It is considered that these data support, but do not provide critical proof for, the interfacial hypothesis, which states that catalase is present at the intracellular interface in question, but is desorbed into solution as a consequence of the alteration process.

scholarly journals Comparison of In Vitro Activities of Camptothecin and Nitidine Derivatives against Fungal and Cancer Cells

1999 ◽  
Vol 43 (12) ◽  
pp. 2862-2868 ◽  
Author(s):  
Maurizio Del Poeta ◽  
Shih-Fong Chen ◽  
Daniel Von Hoff ◽  
Christine C. Dykstra ◽  
Mansukh C. Wani ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Mammalian Cells ◽  
Topoisomerase I ◽  
Active Form ◽  
Antifungal Drugs ◽  
Water Soluble ◽  
Yeast Cells ◽  
Original Structure ◽  
Camptothecin Analogs

ABSTRACT The activities of a series of camptothecin and nitidine derivatives that might interact with topoisomerase I were compared against yeast and cancer cell lines. Our findings reveal that structural modifications to camptothecin derivatives have profound effects on the topoisomerase I-drug poison complex in cells. Although the water-soluble anticancer agents topotecan and irinotecan are less active than the original structure, camptothecin, other derivatives or analogs with substitutions that increase compound solubility have also increased antifungal activities. In fact, a water-soluble prodrug appears to penetrate into the cell and release its active form; the resulting effect in complex with Cryptococcus neoformanstopoisomerase I is a fungicidal response and also potent antitumor activity. Some of the compounds that are not toxic to wild-type yeast cells are extremely toxic to the yeast cells when the C. neoformans topoisomerase I target is overexpressed. With the known antifungal mechanism of a camptothecin-topoisomerase I complex as a cellular poison, these findings indicate that drug entry may be extremely important for antifungal activity. Nitidine chloride exhibits antifungal activity against yeast cells through a mechanism(s) other than topoisomerase I and appears to be less active than camptothecin analogs against tumor cells. Finally, some camptothecin analogs exhibit synergistic antifungal activity against yeast cells in combination with amphotericin B in vitro. Our results suggest that camptothecin and/or nitidine derivatives can exhibit potent antifungal activity and that the activities of camptothecin derivatives with existing antifungal drugs may be synergistic against pathogenic fungi. These new compounds, which exhibit potent antitumor activities, will likely require further structural changes to find more selective activity against fungal versus mammalian cells to hold promise as a new class of antifungal agents.

How do yeast cells become tolerant to high ethanol concentrations?

2016 ◽  
Vol 62 (3) ◽  
pp. 475-480 ◽  
Author(s):  
Tim Snoek ◽  
Kevin J. Verstrepen ◽  
Karin Voordeckers
Keyword(s):  
Yeast Cells ◽  
High Ethanol

scholarly journals Influence of the accumulation of phosphate and magnesium ions in the yeast cells on the ethanol productivity in batch ethanol fermentation

2009 ◽  
Vol 52 (1) ◽  
pp. 153-155 ◽  
Author(s):  
Rafael Almud Villen ◽  
Walter Borzani ◽  
Antonio Sacco Netto
Keyword(s):  
Ethanol Fermentation ◽  
Fermentation Medium ◽  
Ethanol Productivity ◽  
Yeast Cells ◽  
Magnesium Ions

The accumulation of phosphate and magnesium in the yeast cells is not necessary to assure the ethanol productivity of batch ethanol fermentations. To avoid the decrease of the ethanol productivity it was sufficient to use a fermentation medium containing calculated concentrations of phosphorus and magnesium sources in order to maintain practically constant the phosphorus and magnesium initial contents of the biomass during the fermentation.

scholarly journals Use of encapsulated yeast for the treatment of stuck and sluggish fermentations

OENO One ◽  
2002 ◽  
Vol 36 (3) ◽  
pp. 161 ◽  
Author(s):  
Sofia Silva ◽  
Felipe Ramón Portugal ◽  
Patricia Silva ◽  
Maria de Fatima Texeira ◽  
Pierre Strehaiano
Keyword(s):  
Immobilized Cells ◽  
Yeast Cells ◽  
Immobilized Yeast ◽  
Whole Cells ◽  
Volatile Acidity ◽  
Fermentation Tank ◽  
Calcium Alginate Gel ◽  
Immobilized Yeast Cells ◽  
High Ethanol ◽  
Better Than

<p style="text-align: justify;">In this work, encapsulated whole cells of <em>S. cerevisiae</em> in calcium-alginate gel (<em>S. cerevisiae</em>-CAG) were used for the treatment of sluggish and stuck fermentation in vinification. <em>S. cerevisiae</em>-CAG can be applied into the must grape and then they can be withdrawn easily at the end of alcoholic fermentation. For the treatment of sluggish and stuck fermentations, <em>S. cerevisiae</em>-CAG were applied following two steps: firstly <em>S. cerevisiae</em>-CAG were introduced into permeable bags and they were activated in a liquid medium; secondly, after an activation period of eight hours, the immobilized yeast cells were introduced into the fermentation tank. In this work, the obtained results for the treatment of sluggish and stuck fermentations in several French and Portuguese wineries are presented. Preliminary results obtained in micro-vinification conditions have shown that the use of immobilized yeast was better than traditional method (which uses free cells) for the treatment of stuck and sluggish fermentations. The large success rate of immobilized yeast can be explained by one adaptation step of yeast cells to high ethanol concentrations during the immobilization process. The application of immobilized cells of <em>S. cerevisiae</em> under real conditions of vinification has shown a consumption rate of 2.8 g/L per day of reducing sugar with a concentration of 5 million of viable cells per mL. It was never observed any increase of the volatile acidity or of other undesirable compounds.</p>

Modelling of Ethanol Fermentation Coupled with Product Recovery by Pervaporation

2017 ◽  
Vol 68 (11) ◽  
pp. 2708-2715
Author(s):  
Bogdan Trica ◽  
Oana Cristina Parvulescu ◽  
Tanase Dobre ◽  
Ali A. A. Al Janabi ◽  
Cristian Raducanu ◽  
...  
Keyword(s):  
Batch Fermentation ◽  
Ethanol Concentration ◽  
Water System ◽  
Yeast Cells ◽  
Operating Modes ◽  
Surface Areas ◽  
Sugar Fermentation ◽  
Fed Batch Fermentation ◽  
Negative Effect ◽  
High Ethanol

Bioethanol is the most important biofuel produced by fermentation of sugars from various biomass types. The main disadvantages associated to this process consist in the negative effect of high ethanol concentration on the cell growth and in the separation cost of ethanol-water system resulted in the fermentation process. Sugar fermentation using Saccharomyces cerevisiae yeast coupled with bioethanol recovery by pervaporation has been modeled and simulated in this paper. In order to avoid the clogging of pervaporation membrane, the yeast cells were previously retained into an ultrafiltration unit. Three operating modes were analyzed and compared, i.e., classical batch fermentation (BF), batch fermentation coupled with external ultrafiltration and pervaporation (BFPV), and fed batch fermentation coupled with external ultrafiltration and pervaporation (FBFPV). Surface areas of ultrafiltration and pervaporation units were selected as process control variables.

Effects of a high-dose Saccharomyces cerevisiae inoculum alone or in combination with Lactobacillus plantarum on the nutritional composition and fermentation traits of maize silage

2020 ◽  
Vol 60 (6) ◽  
pp. 833
Author(s):  
X. L. Zhou ◽  
Z. Ouyang ◽  
X. L. Zhang ◽  
Y. Q. Wei ◽  
S. X. Tang ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Lactobacillus Plantarum ◽  
Nutritional Composition ◽  
Average Concentration ◽  
Water Soluble ◽  
Yeast Cells ◽  
Soluble Carbohydrate ◽  
High Dose ◽  
Maize Silage ◽  
Aerobic Stability

Context The inoculation of silage with Saccharomyces cerevisiae to deliver viable yeast cells is a novel concept. Aims The effects of a high-dose S. cerevisiae inoculum alone or combined with Lactobacillus plantarum on the nutritional composition, fermentation traits and aerobic stability of maize silage were studied after 30, 60 and 90 days of storage. Methods Whole-crop maize (309.3 g dry matter (DM)/kg as fed) was subjected to one of three treatments: deionised water (untreated control); S. cerevisiae at an estimated concentration of 108 CFU/g fresh forage (S); or S. cerevisiae at an estimated concentration of 108 CFU/g and L. plantarum at an estimated concentration of 105 CFU/g of fresh forage (SL). Key results Compared with the control, the S and SL groups showed increases (P &lt; 0.001) in average pH (3.98 in S and 4.01 in SL vs 3.65 in the control), crude protein (85 g/kg DM in S and 80 g/kg DM in SL vs 63 g/kg DM in the control) and ammonia nitrogen/total nitrogen (122.2 g/kg in S and 163.9 g/kg in SL vs 52.9 g/kg in the control) but a lower (P &lt; 0.001) average concentration of water-soluble carbohydrate (0.9 g/kg DM in S and 0.7 g/kg DM in SL vs 2.3 g/kg DM in the control). The levels of neutral detergent fibre and acid detergent fibre were greater (P &lt; 0.001) in S silage than in the control and SL silages, and the hemicellulose level was lower (P = 0.004) in the SL group than the control and S groups. Starch and aerobic stability were unaffected by treatment, and the average lactate and ethanol concentrations were higher (P &lt; 0.001) in the S (53.7 g lactate/kg DM and 28.7 g ethanol/kg DM) and SL (56.9 g lactate/kg DM and 21.4 g ethanol/kg DM) groups than the control (40.1 g lactate/kg DM and 5.3 g ethanol/kg DM) over 90 days of ensiling. Conclusions Overall, a high-dose inoculum of S. cerevisiae alone or combined with L. plantarum affected the nutritional composition and fermentation traits of maize silage. Implications The inoculation of maize silage with a high dose of S. cerevisiae needs to be performed with caution.

scholarly journals A Novel Injectable Water-Soluble Amphotericin B-Arabinogalactan Conjugate

1999 ◽  
Vol 43 (8) ◽  
pp. 1975-1981 ◽  
Author(s):  
Rama Falk ◽  
Abraham J. Domb ◽  
Itzhack Polacheck
Keyword(s):  
Body Weight ◽  
Amphotericin B ◽  
Water Solubility ◽  
Fungal Infections ◽  
Water Soluble ◽  
Yeast Cells ◽  
High Yield ◽  
Target Organs ◽  
Natural Polysaccharide ◽  
Further Development

ABSTRACT New, stable, highly water-soluble, nontoxic polysaccharide conjugates of amphotericin B (AmB) are described. AmB was conjugated by a Schiff-base reaction with oxidized arabinogalactan (AG). AG is a highly branched natural polysaccharide with unusual water solubility (70% in water). A high yield of active AmB was obtained with the conjugates which were similarly highly water soluble and which could be appropriately formulated for injection. They showed comparable MICs forCandida albicans and Cryptococcus neoformans(MICs, 0.1 to 0.2 μg/ml). The reduced AmB conjugate, which was synthesized at pH 11 for 48 h at 37°C, was nonhemolytic and was much safer than conventional micellar AmB-deoxycholate. It was the least toxic AmB-AG conjugate among those tested with mice (maximal tolerated dose, 50 mg/kg of body weight), and histopathology indicated no damage to the liver or kidneys. This conjugate, similarly to the liposomal formulation (AmBisome), was more effective than AmB-deoxycholate in prolonging survival. It was more effective than both the liposomal and the deoxycholate formulations in eradicating yeast cells from target organs. The overall results suggest that after further development of the AmB-AG conjugate, it may be a potent agent in the treatment of fungal infections.

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