The ability of the rumen ciliates to utilize β-glucans other than cellulose and xylan is currently being recognized. The objective of the present study was to characterize the ability of the ciliate Diploplastron affine to digest some pachyman, laminarin, pustulan, curdlan and lichean. The protozoa were isolated from the rumen of sheep and either grown in vitro or inoculated into the rumen of ciliate-free sheep and maintained in natural conditions. In vitro culture studies showed that the enrichment of culture medium with the examined saccharides results in an increase in the number of ciliates in comparison to the control cultures. The increase was over 36 and 15 % when the growth medium was supplemented with pachyman (1,3-β-glucan) and pustulan (1,6-β-glucan), respectively. A positive correlation was also found between the population density of ciliates and the dose of saccharide supplemented to the growth medium. Enzyme studies were performed using the crude enzyme preparation obtained from ciliates treated with antibiotics. The ability of ciliates to digest the examined β-glucans was tested by the quantification of reducing sugars released from the mentioned substrates during the incubation with crude enzyme preparation. The results showed that D. affine ciliates were able to digest both of them. The mean degradation rate varied between 6.7 and 28.2 μmol/L glucose per mg protein per h for pustulan and lichean, respectively, whereas the digestion velocity was the highest at 5.0-5.5 pH and 45-50°C.

• MeSH
• Rumen metabolism   parasitology   MeSH
• beta-Glucans metabolism   MeSH
• Ciliophora enzymology   metabolism   MeSH
• Sheep MeSH
• Protozoan Proteins metabolism   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• beta-Glucans MeSH
• Protozoan Proteins MeSH

Strains of Saccharomyces cerevisiae lacking Isw2, the catalytic subunit of the Isw2 chromatin remodeling complex, show the mating type-independent activation of the cell wall integrity (CWI) signaling pathway. Since the CWI pathway activation usually reflects cell wall defects, we searched for the cell wall-related genes changed in expression. The genes DSE1, CTS1, and CHS1 were upregulated as a result of the absence of Isw2, according to previously published gene expression profiles (I. Frydlova, M. Basler, P. Vasicova, I. Malcova, and J. Hasek, Curr. Genet. 52:87-95, 2007). Western blot analyses of double deletion mutants, however, did not indicate the contribution of the chitin metabolism-related genes CTS1 and CHS1 to the CWI pathway activation. Nevertheless, the deletion of the DSE1 gene encoding a daughter cell-specific protein with unknown function suppressed CWI pathway activation in isw2Delta cells. In addition, the deletion of DSE1 also abolished the budding-within-the-birth-scar phenotype of isw2Delta cells. The plasmid-driven overexpression proved that the deregulation of Dse1 synthesis was also responsible for CWI pathway activation and manifestation of the budding-within-the-birth-scar phenotype in wild-type cells. The overproduced Dse1-green fluorescent protein localized to both sides of the septum and persisted in unbudded cells. Although the exact cellular role of this daughter cell-specific protein has to be elucidated, our data point to the involvement of Dse1 in bud site selection in haploid cells.

• MeSH
• Cell Wall genetics   metabolism   MeSH
• Cell Division * MeSH
• Gene Deletion MeSH
• Species Specificity MeSH
• Gene Expression Regulation, Fungal * MeSH
• Saccharomyces cerevisiae cytology   genetics   metabolism   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Differentiation of the cell wall of Saccharomyces cerevisiae at the site of the future bud was followed. A lentil-like structure originates on the inner side of the cell wall during the first phase. At the same time, an electron-dense layer occurs at the boundary between the inner layer of the cell wall and the lentil-like structure. During the second phase granular material is accumulated at the lower side of the lentil-like structure. During the third phase the lentil-like structure is split apart due to proliferation of the granular material resulting in formation of the base of the encircling region. The marked electron-dense layer observed from the first phase is attached to the surface of the encircling region during differentiation of the latter. During the budding proper the outer layers of the cell wall protrude and the end of the encircling region, together with the adjacent electron-dense layer, acquire their definitive appearance of rings, observed as marked electron-transparent and electron-dense tears on ultrathin sections.

• MeSH
• Models, Biological MeSH
• Cell Wall drug effects   ultrastructure   MeSH
• Cell Division MeSH
• Time Factors MeSH
• Chitin * MeSH
• Hydrolysis MeSH
• Hydrochloric Acid pharmacology   MeSH
• Polysaccharides * MeSH
• Saccharomyces cerevisiae growth & development   ultrastructure   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Chitin * MeSH
• Hydrochloric Acid MeSH
• Polysaccharides * MeSH

• MeSH
• Staining and Labeling MeSH
• Cell Wall analysis   growth & development   MeSH
• Cellulose MeSH
• Chitin isolation & purification   MeSH
• Microscopy, Electron MeSH
• Microscopy, Fluorescence MeSH
• Cell Fractionation MeSH
• Microscopy, Phase-Contrast MeSH
• Polysaccharides isolation & purification   MeSH
• Saccharomyces cerevisiae analysis   cytology   growth & development   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Cellulose MeSH
• Chitin MeSH
• Polysaccharides MeSH