A cell wall‐associated polysaccharide is required for bacteriophage adsorption to the Streptococcus thermophilus cell surface

2020 ◽  
Vol 114 (1) ◽  
pp. 31-45 ◽  
Author(s):  
Brian McDonnell ◽  
Laurens Hanemaaijer ◽  
Francesca Bottacini ◽  
Philip Kelleher ◽  
Katherine Lavelle ◽  
...  
2002 ◽  
Vol 68 (4) ◽  
pp. 2018-2025 ◽  
Author(s):  
Hitoshi Shimoi ◽  
Kazutoshi Sakamoto ◽  
Masaki Okuda ◽  
Ratchanee Atthi ◽  
Kazuhiro Iwashita ◽  
...  

ABSTRACT Sake, a traditional alcoholic beverage in Japan, is brewed with sake yeasts, which are classified as Saccharomyces cerevisiae. Almost all sake yeasts form a thick foam layer on sake mash during the fermentation process because of their cell surface hydrophobicity, which increases the cells' affinity for bubbles. To reduce the amount of foam, nonfoaming mutants were bred from foaming sake yeasts. Nonfoaming mutants have hydrophilic cell surfaces and no affinity for bubbles. We have cloned a gene from a foam-forming sake yeast that confers foaming ability to a nonfoaming mutant. This gene was named AWA1 and structures of the gene and its product were analyzed. The N- and C-terminal regions of Awa1p have the characteristic sequences of a glycosylphosphatidylinositol anchor protein. The entire protein is rich in serine and threonine residues and has a lot of repetitive sequences. These results suggest that Awa1p is localized in the cell wall. This was confirmed by immunofluorescence microscopy and Western blotting analysis using hemagglutinin-tagged Awa1p. Moreover, an awa1 disruptant of sake yeast was hydrophilic and showed a nonfoaming phenotype in sake mash. We conclude that Awa1p is a cell wall protein and is required for the foam-forming phenotype and the cell surface hydrophobicity of sake yeast.


2022 ◽  
Vol 88 (1) ◽  
Author(s):  
Katherine Lavelle ◽  
Irina Sadovskaya ◽  
Evgeny Vinogradov ◽  
Philip Kelleher ◽  
Gabriele A. Lugli ◽  
...  

Streptococcus thermophilus is an important starter culture bacterium in global dairy fermentation processes, where it is used for the production of various cheeses and yogurt. Bacteriophage predation of the species can result in substandard product quality and, in rare cases, complete fermentation collapse.


2018 ◽  
Vol 84 (23) ◽  
Author(s):  
Paula Szymczak ◽  
Sérgio Raposo Filipe ◽  
Gonçalo Covas ◽  
Finn Kvist Vogensen ◽  
Ana Rute Neves ◽  
...  

ABSTRACTReceptors on the cell surfaces of bacterial hosts are essential during the infection cycle of bacteriophages. To date, the phage receptors of the industrial relevant dairy starter bacteriumStreptococcus thermophilusremain elusive. Thus, we set out to identify cell surface structures that are involved in host recognition by dairy streptococcal phages. Five industrialS. thermophilusstrains sensitive to different phages (pactype,costype, and the new type 987), were selected to generate spontaneous bacteriophage-insensitive mutants (BIMs). Of these, approximately 50% were deselected as clustered regularly interspaced short palindromic repeat (CRISPR) mutants, while the other pool was further characterized to identify receptor mutants. On the basis of genome sequencing data, phage resistance in putative receptor mutants was attributed to nucleotide changes in genes encoding glycan biosynthetic pathways. Superresolution structured illumination microscopy was used to visualize the interactions betweenS. thermophilusand its phages. The phages were either regularly distributed along the cells or located at division sites of the cells. The cell wall structures mediating the latter type of phage adherence were further analyzed via phenotypic and biochemical assays. Altogether, our data suggested that phage adsorption toS. thermophilusis mediated by glycans associated with the bacterial cell surface. Specifically, thepac-type phage CHPC951 adsorbed to polysaccharides anchored to peptidoglycan, while the 987-type phage CHPC926 recognized exocellular polysaccharides associated with the cell surface.IMPORTANCEStreptococcus thermophilusis widely used in starter cultures for cheese and yoghurt production. During dairy fermentations, infections of bacteria with bacteriophages result in acidification failures and a lower quality of the final products. An understanding of the molecular factors involved in phage-host interactions, in particular, the phage receptors in dairy bacteria, is a crucial step for developing better strategies to prevent phage infections in dairy plants.


1994 ◽  
Vol 14 (7) ◽  
pp. 4825-4833 ◽  
Author(s):  
C F Lu ◽  
J Kurjan ◽  
P N Lipke

Saccharomyces cerevisiae alpha-agglutinin is a cell wall-anchored adhesion glycoprotein. The previously identified 140-kDa form, which contains a glycosyl-phosphatidylinositol (GPI) anchor (D. Wojciechowicz, C.-F. Lu, J. Kurjan, and P. N. Lipke, Mol. Cell. Biol. 13:2554-2563, 1993), and additional forms of 80, 150, 250 to 300, and > 300 kDa had the properties of intermediates in a transport and cell wall anchorage pathway. N glycosylation and additional modifications resulted in successive increases in size during transport. The 150- and 250- to 300-kDa forms were membrane associated and are likely to be intermediates between the 140-kDa form and a cell surface GPI-anchored form of > 300 kDa. A soluble form of > 300 kDa that lacked the GPI anchor had properties of a periplasmic intermediate between the plasma membrane form and the > 300-kDa cell wall-anchored form. These results constitute experimental support for the hypothesis that GPI anchors act to localize alpha-agglutinin to the plasma membrane and that cell wall anchorage involves release from the GPI anchor to produce a periplasmic intermediate followed by linkage to the cell wall.


2000 ◽  
Vol 66 (11) ◽  
pp. 4772-4778 ◽  
Author(s):  
María Dolores Fernandez-Espla ◽  
Peggy Garault ◽  
Véronique Monnet ◽  
Françoise Rul

ABSTRACT Streptococcus thermophilus CNRZ 385 expresses a cell envelope proteinase (PrtS), which is characterized in the present work, both at the biochemical and genetic levels. Since PrtS is resistant to most classical methods of extraction from the cell envelopes, we developed a three-step process based on loosening of the cell wall by cultivation of the cells in the presence of glycine (20 mM), mechanical disruption (with alumina powder), and enzymatic treatment (lysozyme). The pure enzyme is a serine proteinase highly activated by Ca2+ ions. Its activity was optimal at 37°C and pH 7.5 with acetyl-Ala-Ala-Pro-Phe-paranitroanilide as substrate. The study of the hydrolysis of the chromogenic and casein substrates indicated that PrtS presented an intermediate specificity between the most divergent types of cell envelope proteinases from lactococci, known as the PI and PIII types. This result was confirmed by the sequence determination of the regions involved in substrate specificity, which were a mix between those of PI and PIII types, and also had unique residues. Sequence analysis of the PrtS encoding gene revealed that PrtS is a member of the subtilase family. It is a multidomain protein which is maturated and tightly anchored to the cell wall via a mechanism involving an LPXTG motif. PrtS bears similarities to cell envelope proteinases from pyogenic streptococci (C5a peptidase and cell surface proteinase) and lactic acid bacteria (PrtP, PrtH, and PrtB). The highest homologies were found with streptococcal proteinases which lack, as PrtS, one domain (the B domain) present in cell envelope proteinases from all other lactic acid bacteria.


1998 ◽  
Vol 9 (1) ◽  
pp. 161-171 ◽  
Author(s):  
Wan-Sheng Lo ◽  
Anne M. Dranginis

Diploid yeast develop pseudohyphae in response to nitrogen starvation, while haploid yeast produce invasive filaments which penetrate the agar in rich medium. We have identified a gene,FLO11, that encodes a cell wall protein which is critically required for both invasion and pseudohyphae formation in response to nitrogen starvation. FLO11 encodes a cell surface flocculin with a structure similar to the class of yeast serine/threonine-rich GPI-anchored cell wall proteins. Cells of theSaccharomyces cerevisiae strain Σ1278b with deletions of FLO11 do not form pseudohyphae as diploids nor invade agar as haploids. In rich media, FLO11 is regulated by mating type; it is expressed in haploid cells but not in diploids. Upon transfer to nitrogen starvation media, however, FLO11transcripts accumulate in diploid cells, but not in haploids. Overexpression of FLO11 in diploid cells, which are otherwise not invasive, enables them to invade agar. Thus, the mating type repression of FLO11 in diploids grown in rich media suffices to explain the inability of these cells to invade. The promoter of FLO11 contains a consensus binding sequence for Ste12p and Tec1p, proteins known to cooperatively activate transcription of Ty1 elements and theTEC1 gene during development of pseudohyphae. Yeast with a deletion of STE12 does not expressFLO11 transcripts, indicating that STE12is required for FLO11 expression. These ste12-deletion strains also do not invade agar. However, the ability to invade can be restored by overexpressing FLO11. Activation ofFLO11 may thus be the primary means by which Ste12p and Tec1p cause invasive growth.


1994 ◽  
Vol 14 (7) ◽  
pp. 4825-4833
Author(s):  
C F Lu ◽  
J Kurjan ◽  
P N Lipke

Saccharomyces cerevisiae alpha-agglutinin is a cell wall-anchored adhesion glycoprotein. The previously identified 140-kDa form, which contains a glycosyl-phosphatidylinositol (GPI) anchor (D. Wojciechowicz, C.-F. Lu, J. Kurjan, and P. N. Lipke, Mol. Cell. Biol. 13:2554-2563, 1993), and additional forms of 80, 150, 250 to 300, and > 300 kDa had the properties of intermediates in a transport and cell wall anchorage pathway. N glycosylation and additional modifications resulted in successive increases in size during transport. The 150- and 250- to 300-kDa forms were membrane associated and are likely to be intermediates between the 140-kDa form and a cell surface GPI-anchored form of > 300 kDa. A soluble form of > 300 kDa that lacked the GPI anchor had properties of a periplasmic intermediate between the plasma membrane form and the > 300-kDa cell wall-anchored form. These results constitute experimental support for the hypothesis that GPI anchors act to localize alpha-agglutinin to the plasma membrane and that cell wall anchorage involves release from the GPI anchor to produce a periplasmic intermediate followed by linkage to the cell wall.


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