scholarly journals Selection of Bacillus subtilis strains capable of producing β-glucanase supporting the hydrolysis of yeast cell walls

2020 ◽  
Vol 3 (1) ◽  
pp. 103
Author(s):  
Le Van Kien ◽  
Hanh Van Vu ◽  
Anh Tuan Ho ◽  
Hoai Thi Thu Pham ◽  
Huong Thi Mai Nguyen ◽  
...  
Keyword(s):  
Yeast Cell ◽  
Cell Walls ◽  
Yeast Cells ◽  
Broth Culture ◽  
Diffusion Method ◽  
Affecting Factors ◽  
Culture Time ◽  
Hydrolysis Of ◽  
Beer Yeast ◽  
Selection Of

The selection of B. subtilis strains was carried out with 15 strains from the collections of the Vietnam National University of Agriculture and the University of Economic and Technical Industries, Hanoi, Vietnam. To investigate the specific ability of β-glucanase in supporting the hydrolysis of beer yeast cells, CMC substrates in enzyme-activated test media of traditional methods was replaced by yeast cell walls in this study. The B. subtilis strains were activated on Nutrient Broth culture and then transplanted into MT3 culture for producing β-glucanase. Optical density (OD600nm) measurement was used to estimate the bacterial density. The β-glucanase activity formed by bacteria cells free supernatant was quantified by agar diffusion method on the enzyme-activated test media MT4. Two B. Subtilis strains , BG21 and BG15, were selected based on their largest clear-zones on agar plates. By modifying the values of the affecting factors and keeping the remaining influencing factors unchanged, it was determined that the B. subtilis BG21 and BG15 strains produced the highest biomass at the conditions of the culture time of 24 and 28 h, at pH 7.0, and at 37oC, respectively; furthermore, the highest activity of β-glucanase of the two strains BG21 and BG15 was exhibited at the culture time of 52 and 56 h, at pH 7.0, and at 37oC, respectively.Practical applicationsBacillus subtilis strains with the highest β-glucanase producing ability will be used for the production of biological products containing B. subtilis and β-glucanase which supports the hydrolysis of the beer yeast cells in the production of pig feed.

L'hydrolyse des hétérosides terpéniques du Muscat a petits grains par les enzymes périplasmiques de Saccharomyces cerevisiae

OENO One ◽  
1988 ◽  
Vol 22 (3) ◽  
pp. 189 ◽  
Author(s):  
Philippe Darriet ◽  
Jean-Noël Boidron ◽  
Denis Dubourdieu
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Yeast Cell ◽  
Cell Walls ◽  
Yeast Cells ◽  
Periplasmic Space ◽  
Enzymatic Extract ◽  
Periplasmic Extract ◽  
Glucosidase Activity ◽  
Aroma Precursors ◽  
Hydrolysis Of

<p style="text-align: justify;">Osidases located in periplasmic space of <em>Saccharomyces cerevisiae</em> are able to hydrolyse monoterpenes heterosides of Muscat grapes. To prepare the periplasmic extract, yeast cell walls are digested with <em>Zymolyase</em> in the presence of an osmotic protector to prevent lysis of the resulting protoplasts; periplasmic enzymes are liberated into the supernatant medium. Monoterpenes heterosides are incubated 48 or 72 hours at 25° C with either intact yeast cells or periplasmic enzymatic extract. Monoterpenes, especially gerianol and nerol, are liberated in these conditions. β-glucosidase activity seems to play an important rôle in these reactions.</p><p style="text-align: justify;">Fungal extracellular β-glucosidases are commonly strongly inhibited by glucose. Surprisingly, the activity of periplasmic yeast β-glucosidase is quite glucose independant. These results suggest that some periplasmic enzymes from yeast may be involved in the hydrolysis of varietal aroma precursors in wines.</p>

Killer Toxins of Yeasts: Inhibitors of Fermentation and Their Adsorption

1987 ◽  
Vol 50 (3) ◽  
pp. 234-238 ◽  
Author(s):  
FERDINAND RADLER ◽  
MANFRED SCHMITT
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Yeast Cell ◽  
Cell Walls ◽  
Killer Toxin ◽  
Yeast Cells ◽  
Toxin Concentration ◽  
Commercial Preparation ◽  
Killer Toxins ◽  
Original Amount

The killer toxin (KT 28), a glycoprotein of Saccharomyces cerevisiae strain 28, was almost completely adsorbed by bentonite, when applied at a concentration of 1 g per liter. No significant differences were found between several types of bentonite. Killer toxin KT 28 is similarly adsorbed by intact yeast cells or by a commercial preparation of yeast cell walls that has been recommended to prevent stuck fermentations. An investigation of the cell wall fractions revealed that the toxin KT 28 was mainly adsorbed by mannan, that removed the toxin completely. The alkali-soluble and the alkali-insoluble β-1,3- and β-1,6-D-glucans lowered the toxin concentration to one tenth of the original amount. The killer toxin of the type K1 of S. cerevisiae was adsorbed much better by glucans than by mannan.

scholarly journals The separation of β-glucanases produced by Cytophaga johnsonii and their role in the lysis of yeast cell walls

1970 ◽  
Vol 120 (1) ◽  
pp. 67-78 ◽  
Author(s):  
J. S. D. Bacon ◽  
A. H. Gordon ◽  
D. Jones ◽  
Irene F. Tayor ◽  
D. M. Webley
Keyword(s):  
Yeast Cell ◽  
Cell Walls ◽  
Culture Fluid ◽  
The Other ◽  
Yeast Cells ◽  
Wall Structure ◽  
Enzyme Preparations ◽  
End Products ◽  
Isolated Cell

1. When Cytophaga johnsonii was grown in the presence of suitable inducers the culture fluid was capable of lysing thiol-treated yeast cell walls in vitro. 2. Autoclaved or alkali-extracted cells, isolated cell walls and glucan preparations made from them were effective inducers, but living yeast cells or cells killed by minimal heat treatment were not. 3. Chromatographic fractionation of lytic culture fluids showed the presence of two types of endo-β-(1→3)-glucanase and several β-(1→6)-glucanases; the latter may be induced separately by growing the myxo-bacterium in the presence of lutean. 4. Extensive solubilization of yeast cell walls was obtained only with preparations of one of these glucanases, an endo-β-(1→3)-glucanase producing as end products mainly oligosaccharides having five or more residues. Lysis by the other endo-β-(1→3)-glucanase was incomplete. 5. The β-(1→6)-glucanases produced a uniform thinning of the cell walls, and mannan–peptide was found in the solution. 6. These results, and the actions of the enzyme preparations on a variety of wall-derived preparations made from baker's yeast, are discussed in the light of present conceptions of yeast cell-wall structure.

Effects of Aging and Heat Treatment on Whole Yeast Cells and Yeast Cell Walls and on Adsorption of Ochratoxin A in a Wine Model System

2008 ◽  
Vol 71 (7) ◽  
pp. 1496-1499 ◽  
Author(s):  
Y. P. NUNEZ ◽  
E. PUEYO ◽  
A. V. CARRASCOSA ◽  
A. J. MARTÍNEZ-RODRÍGUEZ
Keyword(s):  
Heat Treatment ◽  
Yeast Cell ◽  
Ochratoxin A ◽  
Cell Walls ◽  
Model System ◽  
Final Concentration ◽  
Yeast Cells ◽  
Adsorption Mechanisms ◽  
Removal Capacity ◽  
Effects Of Aging

A wine model was evaluated to determine the influence of aging on the ability of whole yeast cells (WY) and yeast cell walls (YCW) to remove ochratoxin A (OTA). Aging and autolysis were monitored for 214 h in the model wine. The original concentration of OTA in the model wine was 10 μg/liter, and WY and YCW were added at a final concentration of 1 g/liter. YCW mannoproteins were involved in the removal of OTA from the model wine through adsorption mechanisms. Aging affected the capacity of WY to remove OTA, but YCW removal capacity remained constant during aging. A previous heat treatment (85°C for 10 min) of WY and YCW increased their removal capacity and increased the efficiency of the decontamination process.

scholarly journals ENCAPSULATION OF LACTOBACILLUS ACIDOPHILUS IN YEAST CELL WALLS (SACCHAROMYCES CEREVISIAE) FOR IMPROVING SURVIVAL IN GASTROINTESTINAL CONDITIONS

2016 ◽  
Vol 54 (4) ◽  
pp. 533
Author(s):  
Le Nguyen Han ◽  
Le Huynh Hong Van ◽  
Tran Van Duc ◽  
Dong Thi Anh Dao
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Yeast Cell ◽  
Cell Walls ◽  
Free Cell ◽  
Yeast Cells ◽  
Extreme Condition ◽  
Cell Contact ◽  
Health Products ◽  
Quality Health ◽  
Direct Cell

In search of high-quality health products, it is required that probiotic preparations consumed in gastro-intestinal condition remain metabolically active and preserve their activity. Several recent studies, consequently, have focused on probiotic protection via encapsulation in order to optimize probiotics’ viability as well as their delivery into gastro-intestinal environment. The objectives of this study were to find out a new material for encapsulation of probiotics, utilizing capsules prepared from Saccharomyces cerevisiae to protect living probiotic cells. The encapsulation of cells was achieved, using the crack scars of the yeast cell walls (YCW) created by the sonication method. Besides, some probiotic cells can be considered as being encapsulated by some surrounded yeast cells by direct cell-cell contact. It is concluded that thanks to encapsulation by yeast cells, probiotic’s metabolic activity and survival are markedly improved. This suggests a high potential in protecting probiotics from the extreme condition of digestion process and can be applied in protecting probiotic preparations in food formulations as well. It was found that encapsulation yield in this study reached its highest point at 82.008 ± 1.123%. Viability of encapsulated probiotic in simulated gastric juice (SGJ) after 150 minutes is 19.048 ± 2.701%, compared to that of free cells at 0%. Likewise, after a 4-hour treatment in simulated intestinal juice (SIJ) (0.5% bile salt) encapsulated probiotic proves better survival at 56.338 ± 5.094% than free cell at 43.677 ± 2.058%.

scholarly journals microspheres made by crosslinking of polyvinyl alcohol with glutaraldehyde functionalized with yeast lysate

2020 ◽  
Vol 64 (3) ◽  
pp. 287-292
Author(s):  
K. V. Laznev ◽  
Zh. V. Ignatovich ◽  
V. E. Agabekov
Keyword(s):  
Polyvinyl Alcohol ◽  
Yeast Cell ◽  
Boiling Point ◽  
Cell Walls ◽  
Water Solution ◽  
Subsequent Treatment ◽  
Yeast Cells ◽  
Phagocytosis Assay ◽  
Yeast Lysate ◽  
Magnetite Particles

Microspheres comparable with yeast cells in size were obtained by the glutaraldehyde crosslinking of polyvinyl alcohol (PVA), whose 25 g/l water solution containing magnetite particles was dispersed in the isooctane/Span 85/Tween 85 medium. yeast cell walls were partially hydrolysed by sonication in formic acid near the boiling point. The microspheres were made targets for phagocytosis by the addition of yeast lysate to the crosslinkable PVA solution and a subsequent treatment of the freshly crosslinked microspheres with diluted yeast lysate. The microspheres were also made fluorescent when the emulsification medium saturated with fluorescent 2-aminopyrimidine derivatives was used. A protocol for phagocytosis assay using the thus modified microspheres was developed.

Total Synthesis and Antibacterial Screening of (±)-6,8-Dihydroxy-3- undecyl-3,4-dihydroisochromen-1-one: A Structural Analogue of Metabolites from Ononis natrix

2019 ◽  
Vol 16 (3) ◽  
pp. 245-248
Author(s):  
Hummera Rafique ◽  
Aamer Saeed ◽  
Ehsan Ullah Mughal ◽  
Muhammad Naveed Zafar ◽  
Amara Mumtaz ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Structural Analog ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Antibacterial Screening ◽  
Maximum Inhibition ◽  
Bacillus Subtilus ◽  
Hydrolysis Of ◽  
Direct Condensation

Background: (±)-6,8-Dihydroxy-3-undecyl-3,4-dihydroisochromen-1-one is one of the structural analog of several substituted undecylisocoumarins isolated from Ononis natrix (Fabaceae), has been successfully synthesized by direct condensation of homopthalic acid (1) with undecanoyl chloride yields isochromen-1-one (2). Methods: Alkaline hydrolysis of (2) gave the corresponding keto-acid (3), which is then reduced to hydroxy acid (4) then its cyclodehydration was carried out with acetic anhydride to afford 3,4- dihydroisochromen-1-one (5). Followed by demethylation step, the synthesis of target 6,8- dihydroxy-7-methyl-3-undecyl-3,4-dihydroisocoumarin (6) was achieved. Results: In vitro antibacterial screening of all the synthesized compounds were carried out against ten bacterial strains by agar well diffusion method. Conclusion: Newly synthesized molecules exhibited moderate antibacterial activity and maximum inhibition was observed against Bacillus subtilus and Salmonella paratyphi.

scholarly journals Optimizing Transformation Frequency of Cryptococcus neoformans and Cryptococcus gattii Using Agrobacterium tumefaciens

2021 ◽  
Vol 7 (7) ◽  
pp. 520
Author(s):  
Jianmin Fu ◽  
Nohelli E. Brockman ◽  
Brian L. Wickes
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Yeast Cell ◽  
Transformation Efficiency ◽  
Transformation Frequency ◽  
Yeast Cells ◽  
Agar Concentration ◽  
Genetic Tool ◽  
Number Of Factors ◽  
Cryptococcus Spp ◽  
Transformation Systems

The transformation of Cryptococcus spp. by Agrobacterium tumefaciens has proven to be a useful genetic tool. A number of factors affect transformation frequency. These factors include acetosyringone concentration, bacterial cell to yeast cell ratio, cell wall damage, and agar concentration. Agar concentration was found to have a significant effect on the transformant number as transformants increased with agar concentration across all four serotypes. When infection time points were tested, higher agar concentrations were found to result in an earlier transfer of the Ti-plasmid to the yeast cell, with the earliest transformant appearing two h after A. tumefaciens contact with yeast cells. These results demonstrate that A. tumefaciens transformation efficiency can be affected by a variety of factors and continued investigation of these factors can lead to improvements in specific A. tumefaciens/fungus transformation systems.

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