Potential of Non- Yeasts as Probiotics and Alternatives to Antibiotics in Animal Production.

Probiotics are live yeast or bacterial organisms that have beneficial effects on the host. Several microorganisms exhibit probiotic properties, the most common types being lactic acid bacteria, , spore-forming bacteria, and some yeast strains. var.

Impact of Dietary Regime and Seasonality on Hindgut's Mycobiota Diversity in Dairy Cows.

We describe and discuss the intestinal mycobiota of dairy cows reared in France following variations in dietary regimes and two seasons. Two groups of 21 animals were followed over a summer and winter period, and another group of 28 animals was followed only during the same summer season. The summer diet was based on grazing supplemented with 3-5 kg/d of maize, grass silage and hay, while the winter diet consisted of 30% maize silage, 25% grass silage, 15% hay and 30% concentrate.

Structure of Lacticaseicin 30 and Its Engineered Variants Revealed an Interplay between the N-Terminal and C-Terminal Regions in the Activity against Gram-Negative Bacteria.

Lacticaseicin 30 is one of the five bacteriocins produced by the Gram-positive CNCM I-5369. This 111 amino acid bacteriocin is noteworthy for being active against Gram-negative bacilli including strains resistant to colistin. Prediction of the lacticaseicin 30 structure using the Alphafold2 pipeline revealed a largely helical structure including five helix segments, which was confirmed by circular dichroism.

Lacticaseicin 30 and Colistin as a Promising Antibiotic Formulation against Gram-Negative β-Lactamase-Producing Strains and Colistin-Resistant Strains.

Antimicrobial resistance is a global health concern across the world and it is foreseen to swell if no actions are taken now. To help curbing this well announced crisis different strategies are announced, and these include the use of antimicrobial peptides (AMP), which are remarkable molecules known for their killing activities towards pathogenic bacteria. Bacteriocins are ribosomally synthesized AMP produced by almost all prokaryotic lineages.

Current Knowledge of the Mode of Action and Immunity Mechanisms of LAB-Bacteriocins.

Bacteriocins produced by lactic acid bacteria (LAB-bacteriocins) may serve as alternatives for aging antibiotics. LAB-bacteriocins can be used alone, or in some cases as potentiating agents to treat bacterial infections. This approach could meet the different calls and politics, which aim to reduce the use of traditional antibiotics and develop novel therapeutic options.

Expression of five class II bacteriocins with activity against in CNCM I-5369, and in a heterologous host.

Five open reading frames viz , and coding class II bacteriocins in CNCM I-5369 strain previously isolated from an Algerian dairy product, were found to be expressed after 24 h of growth. The strain has also shown anti- activity in a narrow pH range between 4.5 and 5.

Impact of seasonality and environmental conditions on yeast diversity from camel's milk collected in Algeria.

During this study, we characterized the seasonality's impact and environmental conditions on the yeast diversity from raw camel's milk collected in Algeria. The yeast counts were estimated to 3.55 × 10 CFU mL, with a maximum of 6.

Fungal diversity of "Tomme d'Orchies" cheese during the ripening process as revealed by a metagenomic study.

Tomme d'Orchies is an artisanal pressed and uncooked cheese produced and marketed in the north of France. This study aimed at showing the fungal microbiota evolution of this cheese using a metagenetic based Illumina technology targeting the ITS2 domain of 5.8S fungal rDNAs.

Anti-Salmonella activity and probiotic trends of Kluyveromyces marxianus S-2-05 and Kluyveromyces lactis S-3-05 isolated from a French cheese, Tomme d'Orchies.

Kluyveromyces marxianus S-2-05 and Kluyveromyces lactis S-3-05 were recently isolated from a traditional French cheese, Tomme d'Orchies, and characterized here for their advantages using a different application perspective. First, we established their anti-Salmonella activity and downregulation of the virulence sopD gene of Salmonella enterica subsp. enterica serovar Typhimurium, mainly in the presence of K.

Use of a metagenetic approach to monitor the bacterial microbiota of "Tomme d'Orchies" cheese during the ripening process.

The study of microbial ecosystems in artisanal foodstuffs is important to complete in order to unveil its diversity. The number of studies performed on dairy products has increased during the last decade, particularly those performed on milk and cheese derivative products. In this work, we investigated the bacterial content of "Tomme d'Orchies" cheese, an artisanal pressed and uncooked French cheese.

Production of the small heat shock protein Lo18 from Oenococcus oeni in Lactococcus lactis improves its stress tolerance.

Lactococcus lactis is a lactic acid bacterium widely used in cheese and fermented milk production. During fermentation, L. lactis is subjected to acid stress that impairs its growth.

Yeast diversity in a traditional French cheese "Tomme d'orchies" reveals infrequent and frequent species with associated benefits.

This study is aimed at unrevealing the yeast diversity of handmade cheese, Tomme d'orchies, produced and marketed in the north of France. A total of 185 yeast colonies were isolated from the surface and core of this cheese. From these, 80 morphologically different colonies were selected and subjected to rep-PCR analysis.

Production of a novel mixture of mycosubtilins by mutants of Bacillus subtilis.

Using promoter exchange and gene knock-out strategies, two mutant strains, the so-called BBG116 and BBG125, were constructed from Bacillus subtilis wild-type strain ATCC 6633, a surfactin and mycosubtilin producer. Compared to the parental strain, both mutants overproduced constitutively mycosubtilin, while BBG125 had lost the ability to synthesize surfactin. Surprisingly, BBG125 was found to produce about 2-fold less mycosubtilin than BBG116 despite an expected higher availability of the cytoplasmic precursors and cofactors pool for biosynthesis.

Distinct amino acids of the Oenococcus oeni small heat shock protein Lo18 are essential for damaged protein protection and membrane stabilization.

The small heat shock protein (smHsp) Lo18 from lactic acid bacteria Oenococcus oeni reduces in vitro thermal aggregation of proteins and modulates the membrane fluidity of native liposomes. An absence of information relating to the way in which the smHsp demonstrates a stabilizing effect for both proteins and membranes prompted this study. We expressed three Lo18 proteins with amino acid substitutions in Escherichia coli to investigate their ability to prevent E.

Temperature dependence of mycosubtilin homologue production in Bacillus subtilis ATCC6633.

Bacillus subtilis ATCC6633 produces mycosubtilin, a non-ribosomally synthesized lipopeptide of the iturin family which presents antagonistic activities toward various phytopathogens. Different homologues with fatty acid moiety varying from C15 to C17 are usually co-produced, with their biological activities increasing with the number of carbons in the fatty acid chain. In the present report, we highlight that growth temperature modulates both the extent of mycosubtilin production and the relative abundance of the different homologues.

A small HSP, Lo18, interacts with the cell membrane and modulates lipid physical state under heat shock conditions in a lactic acid bacterium.

The small heat shock proteins (sHSP) are characterized by a chaperone activity to prevent irreversible protein denaturation. This study deals with the sHSP Lo18 induced by multiple stresses in Oenococcus oeni, a lactic acid bacterium. Using in situ immunocytochemistry and cellular fractionation experiments, we demonstrated the association of Lo18 with the membrane in O.

A new approach for selection of Oenococcus oeni strains in order to produce malolactic starters.

The lactic acid bacterium Oenococcus oeni, mainly responsible for malolactic fermentation (MLF), is used in new winery process as starter culture for direct inoculation. The difficulty to master MLF according to the wine led us to search a new approach to select effective O. oeni strains.

CtsR is the master regulator of stress response gene expression in Oenococcus oeni.

Although many stress response genes have been characterized in Oenococcus oeni, little is known about the regulation of stress response in this malolactic bacterium. The expression of eubacterial stress genes is controlled both positively and negatively at the transcriptional level. Overall, negative regulation of heat shock genes appears to be more widespread among gram-positive bacteria.