scholarly journals Global Survey and Genome Exploration of Bacteriophages Infecting the Lactic Acid Bacterium Streptococcus thermophilus

2017 ◽  
Vol 8 ◽  
Author(s):  
Brian McDonnell ◽  
Jennifer Mahony ◽  
Laurens Hanemaaijer ◽  
Horst Neve ◽  
Jean-Paul Noben ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacterium ◽  
Streptococcus Thermophilus ◽  
Global Survey

scholarly journals Dynamic Changes of Intracellular pH in Individual Lactic Acid Bacterium Cells in Response to a Rapid Drop in Extracellular pH

2000 ◽  
Vol 66 (6) ◽  
pp. 2330-2335 ◽  
Author(s):  
Henrik Siegumfeldt ◽  
K. Björn Rechinger ◽  
Mogens Jakobsen
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactic Acid Bacterium ◽  
Intracellular Ph ◽  
Membrane Filter ◽  
Single Cells ◽  
Streptococcus Thermophilus ◽  
Extracellular Ph ◽  
Lactobacillus Delbrueckii ◽  
Rapid Drop

ABSTRACT We describe the dynamics of changes in the intracellular pH (pHi) values of a number of lactic acid bacteria in response to a rapid drop in the extracellular pH (pHex). Strains of Lactobacillus delbrueckii subsp.bulgaricus, Streptococcus thermophilus, andLactococcus lactis were investigated. Listeria innocua, a gram-positive, non-lactic acid bacterium, was included for comparison. The method which we used was based on fluorescence ratio imaging of single cells, and it was therefore possible to describe variations in pHi within a population. The bacteria were immobilized on a membrane filter, placed in a closed perfusion chamber, and analyzed during a rapid decrease in the pHex from 7.0 to 5.0. Under these conditions, the pHi of L. innocua remained neutral (between 7 and 8). In contrast, the pHi values of all of the strains of lactic acid bacteria investigated decreased to approximately 5.5 as the pHex was decreased. No pronounced differences were observed between cells of the same strain harvested from the exponential and stationary phases. Small differences between species were observed with regard to the initial pHi at pHex 7.0, while different kinetics of pHiregulation were observed in different species and also in different strains of S. thermophilus.

scholarly journals Role of the Sortase A in the Release of Cell-Wall Proteinase PrtS in the Growth Medium of Streptococcus thermophilus 4F44

2021 ◽  
Vol 9 (11) ◽  
pp. 2380
Author(s):  
Ahoefa Ablavi Awussi ◽  
Emeline Roux ◽  
Catherine Humeau ◽  
Zeeshan Hafeez ◽  
Bernard Maigret ◽  
...  
Keyword(s):  
Cell Wall ◽  
Lactic Acid ◽  
Lactic Acid Bacterium ◽  
Proteolytic Activity ◽  
Growth Medium ◽  
Cell Envelope ◽  
Streptococcus Thermophilus ◽  
Sortase A ◽  
Cellular Density

Growth of the lactic acid bacterium Streptococcus thermophilus in milk depends on its capacity to hydrolyze proteins of this medium through its surface proteolytic activity. Thus, strains exhibiting the cell envelope proteinase (CEP) PrtS are able to grow in milk at high cellular density. Due to its LPNTG motif, which is possibly the substrate of the sortase A (SrtA), PrtS is anchored to the cell wall in most S. thermophilus strains. Conversely, a soluble extracellular PrtS activity has been reported in the strain 4F44. It corresponds, in fact, to a certain proportion of PrtS that is not anchored to the cell wall but rather is released in the growth medium. The main difference between PrtS of strain 4F44 (PrtS4F44) and other PrtS concerns the absence of a 32-residue imperfect duplication in the prodomain of the CEP, postulated as being required for the maturation and correct subsequent anchoring of PrtS. In fact, both mature (without the prodomain at the N-terminal extremity) and immature (with the prodomain) forms are found in the soluble PrtS4F44 form along with an intact LPNTG at their C-terminal extremity. Investigations we present in this work show that (i) the imperfect duplication is not implied in PrtS maturation; (ii) the maturase PrtM is irrelevant in PrtS maturation which is probably automaturated; and (iii) SrtA allows for the PrtS anchoring in S. thermophilus but the SrtA of strain 4F44 (SrtA4F44) displays an altered activity.

scholarly journals Draft Genome Sequence of Streptococcus thermophilus C106, a Dairy Isolate from an Artisanal Cheese Produced in the Countryside of Ireland

2015 ◽  
Vol 3 (6) ◽  
Author(s):  
Michiel Wels ◽  
L. Mariela Serrano ◽  
Beerd-Jan Eibrink ◽  
Lennart Backus ◽  
Roger S. Bongers ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacterium ◽  
Genome Sequence ◽  
Dairy Products ◽  
Draft Genome ◽  
Streptococcus Thermophilus ◽  
Draft Genome Sequence

The lactic acid bacterium Streptococcus thermophilus is widely used for the fermentation of dairy products. Here, we present the draft genome sequence of S. thermophilus C106 isolated from an artisanal cheese produced in the countryside of Ireland.

Characterization of the gor gene of the lactic acid bacterium Streptococcus thermophilus CNRZ368

1995 ◽  
Vol 146 (5) ◽  
pp. 371-383 ◽  
Author(s):  
M Pébay ◽  
A.-C Holl ◽  
J.-M Simonet ◽  
B Decaris
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacterium ◽  
Streptococcus Thermophilus

scholarly journals Complete Genome Sequence of Streptococcus thermophilus Strain B59671, Which Naturally Produces the Broad-Spectrum Bacteriocin Thermophilin 110

2017 ◽  
Vol 5 (45) ◽  
Author(s):  
John A. Renye ◽  
David S. Needleman ◽  
George A. Somkuti ◽  
Dennis H. Steinberg
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacterium ◽  
Genome Sequence ◽  
Broad Spectrum ◽  
Complete Genome Sequence ◽  
Complete Genome ◽  
Streptococcus Thermophilus ◽  
Aminobutyric Acid ◽  
Gamma Aminobutyric Acid ◽  
Content Type

ABSTRACT Streptococcus thermophilus strain B59671 is a Gram-positive lactic acid bacterium that naturally produces a broad-spectrum bacteriocin, thermophilin 110, and is capable of producing gamma-aminobutyric acid (GABA). The complete genome sequence for this strain contains 1,821,173 nucleotides, 1,936 predicted genes, and an average G+C content of 39.1%.

Three distinct proteases are responsible for overall cell surface proteolysis in Streptococcus thermophilus .

2021 ◽  
Author(s):  
Mylène Boulay ◽  
Coralie Metton ◽  
Christine Mézange ◽  
Lydie Oliveira Correia ◽  
Thierry Meylheuc ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Cell Surface ◽  
Lactic Acid Bacterium ◽  
Wild Type Strain ◽  
Cell Envelope ◽  
Streptococcus Thermophilus ◽  
Surface Proteins ◽  
Bacterial Vector ◽  
Cell Surface Protease ◽  
Cell Surface Proteolysis

The lactic acid bacterium Streptococcus thermophilus was believed to display only two distinct proteases at the cell surface, namely the cell-envelope protease PrtS and the house-keeping protease HtrA. Using peptidomics, we demonstrate here the existence of an additional active cell-surface protease, which shares significant homology with the SepM protease of Streptococcus mutans . Although all three proteases—PrtS, HtrA, and SepM—are involved in the turnover of surface proteins, they demonstrate distinct substrate specificities. In particular, SepM cleaves proteins involved in cell wall metabolism and cell elongation, and its inactivation has consequences for cell morphology. When all three proteases are inactivated, the residual cell-surface proteolysis of S. thermophilus is approximately 5% of that of the wild-type strain. Importance Streptococcus thermophilus is a lactic acid bacterium widely used as a starter in the dairy industry. Due to its "generally recognized as safe" status and its weak cell-surface proteolytic activity, it is also considered to be a potential bacterial vector for heterologous protein production. Our identification of a new cell surface protease made it possible to construct a mutant strain with a 95% reduction in surface proteolysis, which could be useful in numerous biotechnological applications.

scholarly journals Specialized adaptation of a lactic acid bacterium to the milk environment: the comparative genomics of Streptococcus thermophilus LMD-9

2011 ◽  
Vol 10 (Suppl 1) ◽  
pp. S22 ◽  
Author(s):  
Yong Goh ◽  
Caitlin Goin ◽  
Sarah O’Flaherty ◽  
Eric Altermann ◽  
Robert Hutkins
Keyword(s):  
Lactic Acid ◽  
Comparative Genomics ◽  
Lactic Acid Bacterium ◽  
Streptococcus Thermophilus
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