Bruno Pot

Complete Genome Sequence of the Dairy Isolate Lactobacillus acidipiscis ACA-DC 1533

ABSTRACT Lactobacillus acidipiscis is a Gram-positive lactic acid bacterium belonging to the Lactobacillus salivarius clade. Here, we present the first complete genome sequence of L. acidipiscis isolated from traditional Greek Kopanisti cheese. Strain ACA-DC 1533 may play a key role in the strong organoleptic characteristics of Kopanisti cheese.

L. plantarum WCFS1 enhances Treg frequencies by activating DCs even in absence of sampling of bacteria in the Peyer Patches

Probiotics such as L. plantarum WCFS1 can modulate immune responses in healthy subjects but how this occurs is still largely unknown. Immune-sampling in the Peyer Patches has been suggested to be one of the mechanisms. Here we studied the systemic and intestinal immune effects in combination with a trafficking study through the intestine of a well-established immunomodulating probiotic, i.e. L. plantarum WCFS1. We demonstrate that not more than 2–3 bacteria were sampled and in many animals not any bacterium could be found in the PP. Despite this, L. plantarum was associated with a strong increase in infiltration of regulatory CD103+ DCs and generation of regulatory T cells in the spleen. Also, a reduced splenic T helper cell cytokine response was observed after ex vivo restimulation. L. plantarum enhanced Treg cells and attenuated the T helper 2 response in healthy mice. We demonstrate that, in healthy mice, immune sampling is a rare phenomenon and not required for immunomodulation. Also in absence of any sampling immune activation was found illustrating that host-microbe interaction on the Peyer Patches was enough to induce immunomodulation of DCs and T-cells.

Probiotics and Prebiotics: An Overview on Recent Trends

The ban of antibiotics at subtherapeutic levels as growth promoters in animals, along with the emerging challenges and prospects deriving from the use of probiotics and prebiotics in humans, opened the era of similar applications in the field of animal nutrition. Probiotics and prebiotics as novel additives in animal feeding aiming at host-protecting functions, which can maintain animal health and welfare, create fascinating options in favor of both animals and consumers of products of animal origin. In recent years, a considerable amount of knowledge regarding the potential of probiotics and prebiotics as supplements at prophylactic and therapeutic level has been accumulated. However, several bottlenecks are still observed, not only at the science, technology, and application level but also at the regulatory level. In this chapter, we summarize the current knowledge, along with the future trends on the applications of probiotics and prebiotics in animals and more specifically in polygastric, monogastric, and aquatic animals, pets, and bees. Moreover, we discuss the respective regulatory frame and its limitations.

Comparative Genomics of Lactobacillus acidipiscis ACA-DC 1533 Isolated From Traditional Greek Kopanisti Cheese Against Species Within the Lactobacillus salivarius Clade

Lactobacillus acidipiscis belongs to the Lactobacillus salivarius clade and it is found in a variety of fermented foods. Strain ACA-DC 1533 was isolated from traditional Greek Kopanisti cheese and among the available L. acidipiscis genomes it is the only one with a fully sequenced chromosome. L. acidipiscis strains exhibited a high degree of conservation at the genome level. Investigation of the distribution of prophages and Clustered Regularly Interspaced Short Palindromic Repeats (CRISPRs) among the three strains suggests the potential existence of lineages within the species. Based on the presence/absence patterns of these genomic traits, strain ACA-DC 1533 seems to be more related to strain JCM 10692T than strain KCTC 13900. Interestingly, strains ACA-DC 1533 and JCM 10692T which lack CRISPRs, carry two similar prophages. In contrast, strain KCTC 13900 seems to have acquired immunity to these prophages according to the sequences of spacers in its CRISPRs. Nonetheless, strain KCTC 13900 has a prophage that is absent from strains ACA-DC 1533 and JCM 10692T. Furthermore, comparative genomic analysis was performed among L. acidipiscis ACA-DC 1533, L. salivarius UCC118 and Lactobacillus ruminis ATCC 27782. The chromosomes of the three species lack long-range synteny. Important differences were also determined in the number of glycobiome related proteins, proteolytic enzymes, transporters, insertion sequences and regulatory proteins. Moreover, no obvious genomic traits supporting a probiotic potential of L. acidipiscis ACA-DC 1533 were detected when compared to the probiotic L. salivarius UCC118. However, the existence of more than one glycine-betaine transporter within the genome of ACA-DC 1533 may explain the ability of L. acidipiscis to grow in fermented foods containing high salt concentrations. Finally, in silico analysis of the L. acidipiscis ACA-DC 1533 genome revealed pathways that could underpin the production of major volatile compounds during the catabolism of amino acids that may contribute to the typical piquant flavors of Kopanisti cheese.

Whole-Genome Sequence of the Cheese Isolate Lactobacillus rennini ACA-DC 565

ABSTRACT In this study, we present the first complete genome sequence of Lactobacillus rennini ACA-DC 565, a strain isolated from a traditional Greek overripened Kopanisti cheese called Mana. Although the species has been associated with cheese spoilage, the strain ACA-DC 565 may contribute to the intense organoleptic characteristics of Mana cheese.

Understanding immunomodulatory effects of probiotics.

The intestinal microbiota is known to be a driving force in the development and maintenance of the immune system. While substantial shifts in the microbiota composition may influence immune functionality in a longer term, short occasional changes might also be sensed. The latter opens considerable perspectives for the use of nutritional interventions, intended to modulate immune functionality in a desired direction. Probiotics are discussed here as a possible way to achieve this goal. It seems that effects are not only strain specific, but will depend on many environmental factors that make the immune system receptive or not to the influences of a given probiotic strain. The interactions between probiotics on the one hand and enterocytes or immune cells on the other hand, are a complex interplay that is rarely mediated by a single mechanism. Immunomodulation through nutrition is therefore a complex phenomenon that needs careful consideration, understanding of immune functionality as well as insight into the mechanisms of probiotic activities. Only then can the proper clinical trials with proper readouts be set up to prove efficacy of each strain/mixture individually.