: A Source of Postbiotics Displaying Anti-Inflammatory Effects in THP 1 Macrophages.

In addition to traditional use in fermented dairy products, also exhibits anti-inflammatory properties both in live and heat-inactivated form. Recent studies have highlighted that some hydrolysates from surface proteins of could be responsible partially for overall anti-inflammatory activity of this bacterium. It was hypothesized that anti-inflammatory activity could also be attributed to peptides resulting from the digestion of intracellular proteins of .

Cell Proteins Obtained by Peptic Shaving of Two Phenotypically Different Strains of as a Source of Anti-Inflammatory Peptides.

, a food grade bacterium, is extensively used in the manufacture of fermented products such as yogurt and cheeses. It has been shown that strains exhibited varying anti-inflammatory activities in vitro. Our previous study displayed that this activity could be partially due to peptide(s) generated by trypsin hydrolysis of the surface proteins of LMD-9.

Little Impact of NaCl Reduction in Swiss-Type Cheese.

Reducing salt intake can mitigate the prevalence of metabolic disorders. In fermented foods such as cheeses, however, salt can impact the activity of desirable and undesirable microorganisms and thus affect their properties. This study aimed to investigate the effect of salt level on Swiss-type cheese ripening.

In Vitro Anti-Inflammatory Activity of Peptides Obtained by Tryptic Shaving of Surface Proteins of LMD-9.

, a lactic acid bacterium widely used in the dairy industry, is consumed regularly by a significant proportion of the population. Some strains show in vitro anti-inflammatory activity which is not fully understood. We hypothesized that peptides released from the surface proteins of this bacterium during digestion could be implied in this activity.

Role of the Sortase A in the Release of Cell-Wall Proteinase PrtS in the Growth Medium of 4F44.

Growth of the lactic acid bacterium 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 strains.

Identification of Genes Specifically Expressed under Simulated Human Digestive Conditions Using R-IVET Technology.

Despite promising health effects, the probiotic status of a lactic acid bacterium widely used in dairy industry, requires further documentation of its physiological status during human gastrointestinal passage. This study aimed to apply recombinant-based in vivo technology (R-IVET) to identify genes triggered in a LMD-9 reference strain under simulated digestive conditions. First, the R-IVET chromosomal cassette and plasmid genomic library were designed to positively select activated genes.

Importance of digestive mucus and mucins for designing new functional food ingredients.

The mucus, mainly composed of the glycoproteins mucins, is a rheological substance that covers the intestinal epithelium and acts as a protective barrier against a variety of harmful molecules, microbial infection and varying lumen environment conditions. Alterations in the composition or structure of the mucus could lead to various diseases such as inflammatory bowel disease or colorectal cancer. Recent studies revealed that an exogenous intake of probiotic bacteria or other dietary components (such as bioactive peptides and probiotics) derived from food influence mucus layer properties as well as modulate gene expression and secretion of mucins.

Implication of sortase-dependent proteins of Streptococcus thermophilus in adhesion to human intestinal epithelial cell lines and bile salt tolerance.

Streptococcus thermophilus (ST) is a lactic acid bacterium widely used in dairy industry and displays several properties which could be beneficial for host. The objective of this study was to investigate, in vitro, the implication of sortase A (SrtA) and sortase-dependent proteins (SDPs) in the adhesion of ST LMD-9 strain to intestinal epithelial cells (IECs) and resistance to bile salt mixture (BSM; taurocholoate, deoxycholate, and cholate). The effect of mutations in prtS (protease), mucBP (MUCin-Binding Protein), and srtA genes in ST LMD-9 in these mechanisms were examined.

Streptococcus thermophilus, an emerging and promising tool for heterologous expression: Advantages and future trends.

Streptococcus thermophilus is the second most used bacterium in dairy industry. It is daily consumed by millions of people through the worldwide consumption of yogurts, cheeses and fermented milks. S.

The naturally competent strain Streptococcus thermophilus LMD-9 as a new tool to anchor heterologous proteins on the cell surface.

Background: From fundamental studies to industrial processes, synthesis of heterologous protein by micro-organisms is widely employed. The secretion of soluble heterologous proteins in the extracellular medium facilitates their recovery, while their attachment to the cell surface permits the use of the recombinant host cells as protein or peptide supports. One of the key points to carry out heterologous expression is to choose the appropriate host.

Development of the recombinase-based in vivo expression technology in Streptococcus thermophilus and validation using the lactose operon promoter.

Aims: To construct and validate the recombinase-based in vivo expression technology (R-IVET) tool in Streptococcus thermophilus (ST).

Methods And Results: The R-IVET system we constructed in the LMD-9 strain includes the plasmid pULNcreB allowing transcriptional fusion with the gene of the site-specific recombinase Cre and the chromosomal cassette containing a spectinomycin resistance gene flanked by two loxP sites. When tested in M17 medium, promoters of the genes encoding the protease PrtS, the heat-shock protein Hsp16 and of the lactose operon triggered deletion of the cassette, indicating promoter activity in these conditions.

Variability of hydrolysis of β-, αs1-, and αs2-caseins by 10 strains of Streptococcus thermophilus and resulting bioactive peptides.

Milk proteins contain numerous potential bioactive peptides, which may be released by digestive proteases or by the proteolytic system of lactic acid bacteria during food processing. The capacity of Streptococcus thermophilus to generate peptides, especially bioactive peptides, from bovine caseins was investigated. Strains expressing various levels of the cell envelope proteinase, PrtS, were incubated with α(s1)-, α(s2)-, or β-casein.

Original features of cell-envelope proteinases of Lactobacillus helveticus. A review.

Lactobacillus helveticus is a lactic acid bacterium very used in fermented milks and cheese. The rapid growth of L. helveticus in milk is supported by an efficient cell envelope proteinase (CEP) activity, due to subtilisin-like serine proteases.

prtH2, not prtH, is the ubiquitous cell wall proteinase gene in Lactobacillus helveticus.

Lactobacillus helveticus strains possess an efficient proteolytic system that releases peptides which are essential for lactobacillus growth in various fermented dairy products and also affect textural properties or biological activities. Cell envelope proteinases (CEPs) are bacterial enzymes that hydrolyze milk proteins. In the case of L.

Implication of stringent response in the increase of mutability of the whiG and whiH genes during Streptomyces coelicolor development.

In Streptomyces ambofaciens, genetic instability occurring during aerial mycelium development gives rise to white mutant papillae on colonies. Pig-pap mutants deriving from such papillae are unable to sporulate and devoid of the large genome rearrangement usually observed in the other Streptomyces mutants that genetic instability generated. Pig-pap mutants frequently harboured discrete mutations affecting the whiG gene.

Genetic instability of whiG gene during the aerial mycelium development of Streptomyces ambofaciens ATCC23877 under different conditions of nitrogen limitations.

In Streptomyces ambofaciens, white papillae that genetic instability events generate during aerial mycelium growth, give rise to Pig-pap mutants which are unable to sporulate and devoid of large genome rearrangement. Knowing that genetic and environmental factors can influence the number of papillae per colony, we investigated the effect of nutrient limitated conditions of growth on the formation of white papillae. We observed that under nitrogen limitation and, most particularly, under amino acid limitation, the number of papillae per colony dramatically increased.