scholarly journals Brussowvirus SW13 Requires a Cell Surface-Associated Polysaccharide To Recognize Its Streptococcus thermophilus Host

2022 ◽  
Vol 88 (1) ◽  
Author(s):  
Katherine Lavelle ◽  
Irina Sadovskaya ◽  
Evgeny Vinogradov ◽  
Philip Kelleher ◽  
Gabriele A. Lugli ◽  
...  
Keyword(s):  
Cell Surface ◽  
Product Quality ◽  
Starter Culture ◽  
Streptococcus Thermophilus ◽  
Content Type ◽  
Fermentation Processes ◽  
A Cell ◽  
Dairy Fermentation

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.

scholarly journals Biofilm Formation on Stainless Steel by Streptococcus thermophilus UC8547 in Milk Environments Is Mediated by the Proteinase PrtS

2017 ◽  
Vol 83 (8) ◽  
Author(s):  
D. Bassi ◽  
F. Cappa ◽  
S. Gazzola ◽  
L. Orrù ◽  
P. S. Cocconcelli
Keyword(s):  
Stainless Steel ◽  
Biofilm Formation ◽  
Starter Culture ◽  
High Capacity ◽  
Milk Proteins ◽  
Streptococcus Thermophilus ◽  
Content Type ◽  
Factors Affecting ◽  
Ecological Benefit ◽  
Cell Envelopes

ABSTRACT In Streptococcus thermophilus, gene transfer events and loss of ancestral traits over the years contribute to its high level of adaptation to milk environments. Biofilm formation capacity, a phenotype that is lost in the majority of strains, plays a role in persistence in dairy environments, such as milk pasteurization and cheese manufacturing plants. To investigate this property, we have studied S. thermophilus UC8547, a fast-acidifying dairy starter culture selected for its high capacity to form biofilm on stainless steel under environmental conditions resembling the dairy environment. Using a dynamic flow cell apparatus, it was shown that S. thermophilus UC8547 biofilm formation on stainless steel depends on the presence of milk proteins. From this strain, which harbors the prtS gene for the cell wall protease and shows an aggregative phenotype, spontaneous mutants with impaired biofilm capacity can be isolated at high frequency. These mutants lack the PrtS expendable island, as confirmed by comparison of the genome sequence of UC8547Δ3 with that of the parent strain. The prtS island excision occurs between two 26-bp direct repeats located in the two copies of the ISSth1 flanking this genomic island. The central role of PrtS was confirmed by analyzing the derivative strain UC8547Δ16, whose prtS gene was interrupted by an insertional mutation, thereby making it incapable of biofilm formation. PrtS, acting as a binding substance between the milk proteins adhered to stainless steel and S. thermophilus cell envelopes, mediates biofilm formation in dairy environments. This feature provides S. thermophilus with an ecological benefit for its survival and persistence in this environment. IMPORTANCE The increased persistence of S. thermophilus biofilm has consequences in the dairy environment: if, on the one hand, the release of this microorganism from biofilm can promote the fermentation of artisanal cheeses, under industrial conditions it may lead to undesirable contamination of dairy products. The study of the molecular mechanism driving S. thermophilus biofilm formation provides increased knowledge on how an ancestral trait affects relevant phenotypes, such as persistence in the environment and efficiency of growth in milk. This study provides insight into the genetic factors affecting biofilm formation at dairy plants.

scholarly journals Cell Wall Glycans Mediate Recognition of the Dairy BacteriumStreptococcus thermophilusby Bacteriophages

2018 ◽  
Vol 84 (23) ◽  
Author(s):  
Paula Szymczak ◽  
Sérgio Raposo Filipe ◽  
Gonçalo Covas ◽  
Finn Kvist Vogensen ◽  
Ana Rute Neves ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cell Surface ◽  
Streptococcus Thermophilus ◽  
Starter Cultures ◽  
Host Recognition ◽  
Structured Illumination ◽  
Sequencing Data ◽  
Structured Illumination Microscopy ◽  
Content Type ◽  
Type Phage

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.

Isolation, characterization and utilization of starter cultures for the development of wheyghurt drink

2013 ◽  
Vol 115 (8) ◽  
pp. 1169-1186 ◽  
Author(s):  
Muhammad Saeed ◽  
Faqir Muhammad Anjum ◽  
Moazzam Rafiq Khan ◽  
Muhammad Issa Khan ◽  
Muhammad Nadeem
Keyword(s):  
Starter Culture ◽  
Streptococcus Thermophilus ◽  
Starter Cultures ◽  
Organoleptic Evaluation ◽  
Content Type ◽  
Overall Acceptability ◽  
Minimum Score ◽  
Good Nutrition ◽  
Sensory Parameters ◽  
And Storage

PurposeWhey products have conventionally been professed as a means of reducing ingredient costs. The authentic benefits of adding whey products are the enhanced worth resulting from flavor, texture and nutritional improvements as well as nutraceutical or health‐enhancing payback. Therefore, the present study aims to isolate and characterize suitable starter cultures for the production of wheyghurt drink.Design/methodology/approachKeeping in view all the benefits of yoghurt technology this study was planned to isolate the starter cultures and optimize the conditions for the production of wheyghurt drink. The starter cultures (Lactobacillus delbruceckii ssp. Bulgaricus and Streptococcus thermophilus) were isolated from the yoghurt and further characterized on the basis of their morphological and biochemical characteristics. The wheyghurt drink prepared from starter cultures with varying starter culture concentrations (1, 1.5, 2 and 2.5 percent) was analyzed for the physicochemical and sensory characteristics to explore the potential of wheyghurt drink.FindingsDuring storage, color, flavor, taste and overall acceptability were affected significantly. But the interaction between treatments and storage was found non‐significant to all the sensory parameters. At zero day maximum score (7.40) for overall acceptability was recorded for T3 and minimum score (5.60) was awarded to T4. After five, ten and 15 days of storage, judges observed a slight decline in overall acceptability in all wheyghurt drink samples. Hence it was concluded that wheyghurt drink sample T3 obtained maximum scores regarding the organoleptic evaluation and remained the best.Practical implicationsThe key to growth is a continuous evaluation and modification of the product to match consumer expectations. Currently there are many apparent benefits that result from incorporating selected whey products into yogurt formulas. The starter cultures for the production of fermented whey products are not presently produced in Pakistan and are imported for industrial use. The use of LAB as starter culture may help to improve the quality and shelf life of the whey products.Originality/valueThe research is useful for food manufacturers in order to develop functional food products for consumers. Understanding consumer needs and preferences is critical to successful product development and enhancing marketing values of a product. Nutritionally improved foods, such as wheyghurt over the conventional counterpart, will be highly successful in the marketplace. Consumers will prefer such kinds of foods because they are more conscious about their health and such foods provide them with what they desire, i.e. health benefits with good nutrition.

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 ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cell Surface ◽  
Streptococcus Thermophilus ◽  
A Cell

Analysis of the Cell Surface Hydrophobicity of Yoghurt Fermentation Bacteria

2011 ◽  
Vol 361-363 ◽  
pp. 1274-1278 ◽  
Author(s):  
Jia Li Lv ◽  
Wei Jun Zhao
Keyword(s):  
Cell Surface ◽  
Influencing Factors ◽  
Cell Surface Hydrophobicity ◽  
Streptococcus Thermophilus ◽  
Surface Hydrophobicity ◽  
Lactobacillus Bulgaricus ◽  
High Quality ◽  
Adhesion Ability ◽  
Future Production ◽  
Dairy Fermentation

The cell surface hydrophobicity (CSH) of lactic acid bacteria was considered to colonization and adhesion, and playing a prebiotic function in the digestive tract. Therefore, CSH of yoghurt fermentation bacteria most commonly used was analyzed, such as Lactobacillus acidophilus, Lactobacillus bulgaricus and Streptococcus thermophilus to identify initially CSH and the influencing factors of CSH of these strains and provided a theoretical basis for the future production of high-quality dairy fermentation agents and probiotics. The method of bacterial adhesion to hydrocarbons (BATH) was utilized to determine CSH of these strains and used the different conditions to process the cell. Through this research, the results was that L. acidophilus had a strong CSH, greater than L. bulgaricus and S. thermophilus. And the influencing factors of CSH of L. acidophilus were time, temperature, pH, concentration, Ca2+ and protease. But CSH was significantly reduced by trypsin and pepsin. CSH L. acidophilus was connected with the adhesion ability. In addition, it was speculated that some substances which could mediate CSH of L. acidophilus may be a class of proteins. Therefore, in the process of dairy fermentation agent, these factors could be controlled to obtain high-quality products.

Effects of different starter cultures on the ripening characteristics of Golot cheese

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Hayriye Sekban ◽  
Zekai Tarakci
Keyword(s):  
Positive Impact ◽  
Starter Culture ◽  
Control Sample ◽  
Streptococcus Thermophilus ◽  
Sensory Properties ◽  
Starter Cultures ◽  
Lactobacillus Helveticus ◽  
Lactobacillus Bulgaricus ◽  
Content Type ◽  
Positive Effects

Purpose The purpose of this study was to investigate the chemical, textural and sensory properties of some starter cultures fruit-added Golot cheese. Design/methodology/approach Six types of Golot cheeses were produced in this study. While the control sample contained no starter cultures, five different starter culture combinations (GS1: Streptococcus thermophilus, Lactococcus lactis subsp. cremoris, L. lactis subsp. lactis and Lactobacillus bulgaricus; GS2: S. thermophilus and L. bulgaricus; GS3: S. thermophilus; GS4: S. thermophilus and Lactobacillus helveticus; and GS5: S. thermophilus, L. lactis subsp. cremoris and L. lactis subsp. lactis) were applied to the other cheese samples using an immersion technique. Then, all cheeses were vacuum-packed and ripened at 4 ± 1°C for three months and their chemical, biochemical, sensory and textural analyses were performed on the 2nd, 15th, 30th, 60th and 90th days of ripening. Findings Results indicated that generally starter cultures have positive effects on the chemical, biochemical and sensory properties of Golot cheese. Considering the final values, the addition of starter cultures enhanced the ripening index of Golot cheeses (8.4%–9.2%), except the GS3 (7.4%), compared to the control (8.1%). At the end of the ripening period, meltability values of GS4 (16.5 mm) cultured cheeses were higher than those of other cultured cheeses (13.0–15.5 mm) and control cheese (14.5 mm). While lipolysis values were low in fresh cheese, it increased during ripening. Overall, GS3 (2.46 acid degree value [ADV]) and GS4 (2.40 ADV) had the highest lipolysis rate, while GS1 (2.14 ADV) had the lowest (p = 0.07). Electrophoretograms indicated that the highest fragmentation of α- and ß-casein occurred in GS5 (48.43%) and GS1 (44.24%), respectively. Also, GS5 was the most appreciated and preferred cheese in terms of sensory. Regarding texture, hardness, cohesiveness, adhesiveness, springiness and gumminess values were determined to be statistically important in terms of ripening time and cheese variety (p < 0.01). Originality/value Consequently, all starters had a positive impact on Golot cheese samples and among all S. thermophilus and L. helveticus starter were determined to be the most applicable one considering ripening, texture, sensory and melting properties.

scholarly journals Identification of a Novel Elastin-Degrading Enzyme from the Fish PathogenFlavobacterium psychrophilum

2019 ◽  
Vol 85 (6) ◽  
Author(s):  
T. Rochat ◽  
D. Pérez-Pascual ◽  
H. Nilsen ◽  
M. Carpentier ◽  
S. Bridel ◽  
...  
Keyword(s):  
Cell Surface ◽  
Pathogenic Bacteria ◽  
Bacterial Pathogen ◽  
Salmonid Fish ◽  
Economic Losses ◽  
Gene Encoding ◽  
Content Type ◽  
Flavobacterium Psychrophilum ◽  
A Genome ◽  
A Cell

ABSTRACTHydrolytic extracellular enzymes degrading host tissues potentially play a role in bacterial pathogenesis.Flavobacterium psychrophilumis an important bacterial pathogen of salmonid fish reared in freshwater throughout the world. Diversity among isolates has been described at the phenotypic, serological, and genomic levels, but the links between these various traits remain poorly understood. Using a genome-wide association study, we identified a gene encoding a novel elastinolytic enzyme inF. psychrophilum. To formally demonstrate enzymatic activity, this gene (FP0506from strain JIP 02/86) was expressed in the elastinolysis-deficient strain OSU THCO2-90, resulting in proficient elastin-degrading cells. The encoded protein is predicted to be a cell-surface-exposed lipoprotein with no homology to previously reported elastases. FP0506 might belong to the zincin tribe and gluzincin clan of metalloproteases, and this new elastase-encoding gene seems to be present only in some members of the familyFlavobacteriaceae.IMPORTANCEElastin is an important proteinaceous component of vertebrate connective tissues (e.g., blood vessels, lung, and skin), to which it confers elasticity. Elastases have been identified in a number of pathogenic bacteria. They are thought to be required for tissue penetration and dissemination, acting as “spreading factors.”Flavobacterium psychrophilumis a devastating bacterial pathogen of salmonid fish (salmon and trout) that is responsible for severe economic losses worldwide. This pathogen displays strong proteolytic activities. Using a variety of techniques, including genome comparisons, we identified a gene encoding a novel elastase inF. psychrophilum. The encoded protein is predicted to be a cell-surface-exposed lipoprotein with no homology to previously reported elastases. In addition, this elastase likely belongs to a new family of proteases that seems to be present only in some members of this important group of bacteria.

scholarly journals Complete Genome Sequences of 28 Lactococcal Bacteriophages Isolated from Failed Dairy Fermentation Processes

2020 ◽  
Vol 9 (12) ◽  
Author(s):  
Barbara Marcelli ◽  
Anne de Jong ◽  
Thomas Janzen ◽  
Mariela Serrano ◽  
Jan Kok ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacterium ◽  
Lactococcus Lactis ◽  
Complete Genome ◽  
Fermented Foods ◽  
Genome Sequences ◽  
Content Type ◽  
Fermentation Processes ◽  
The World ◽  
Dairy Fermentation

Lactococcus lactis is a Gram-positive lactic acid bacterium commonly used in the dairy industry for the production of fermented foods such as buttermilk and a wide variety of cheeses. Here, we report the complete genome sequences of 28 bacteriophages infecting different L. lactis industrial starter strains isolated from dairy plants throughout the world.

scholarly journals Cell Surface Polysaccharides Represent a Common Strategy for Adsorption among Phages Infecting Lactic Acid Bacteria: Lessons from Dairy Lactococci and Streptococci

mSystems ◽  
2021 ◽  
Vol 6 (4) ◽  
Author(s):  
Jennifer Mahony
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Cell Surface ◽  
Lactococcus Lactis ◽  
Streptococcus Thermophilus ◽  
Starter Cultures ◽  
Content Type ◽  
Common Strategy ◽  
Surface Polysaccharides

Food fermentations rely on the application of robust bacterial starter cultures, the majority of which are represented by members of the lactic acid bacteria including Lactococcus lactis and Streptococcus thermophilus . Bacteriophage (or phage) proliferation remains one of the most significant threats to the fermentation industry.

scholarly journals Assembly of Minicellulosomes on the Surface of Bacillus subtilis

2011 ◽  
Vol 77 (14) ◽  
pp. 4849-4858 ◽  
Author(s):  
Timothy D. Anderson ◽  
Scott A. Robson ◽  
Xiao Wen Jiang ◽  
G. Reza Malmirchegini ◽  
Henri-Pierre Fierobe ◽  
...  
Keyword(s):  
Cell Wall ◽  
Bacillus Subtilis ◽  
Cell Surface ◽  
Noncovalent Interactions ◽  
Genetic System ◽  
Cellulolytic Bacteria ◽  
Content Type ◽  
Multienzyme Complexes ◽  
Wide Range ◽  
A Cell

ABSTRACTTo cost-efficiently produce biofuels, new methods are needed to convert lignocellulosic biomass into fermentable sugars. One promising approach is to degrade biomass using cellulosomes, which are surface-displayed multicellulase-containing complexes present in cellulolyticClostridiumandRuminococcusspecies. In this study we created cellulolytic strains ofBacillus subtilisthat display one or more cellulase enzymes. Proteins containing the appropriate cell wall sorting signal are covalently anchored to the peptidoglycan by coexpressing them with theBacillus anthracissortase A (SrtA) transpeptidase. This approach was used to covalently attach the Cel8A endoglucanase fromClostridium thermocellumto the cell wall. In addition, a Cel8A-dockerin fusion protein was anchored on the surface ofB. subtilisvia noncovalent interactions with a cell wall-attached cohesin module. We also demonstrate that it is possible to assemble multienzyme complexes on the cell surface. A three-enzyme-containing minicellulosome was displayed on the cell surface; it consisted of a cell wall-attached scaffoldin protein noncovalently bound to three cellulase-dockerin fusion proteins that were produced inEscherichia coli.B. subtilishas a robust genetic system and is currently used in a wide range of industrial processes. Thus, grafting larger, more elaborate minicellulosomes onto the surface ofB. subtilismay yield cellulolytic bacteria with increased potency that can be used to degrade biomass.

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