Carbamoylphosphate synthetase activity is essential for the optimal growth of Streptococcus thermophilus in milk

AIM: The aim of the study was to study the role of carbon dioxide metabolism in Streptococcus thermophilus through investigation of the phenotype of a carbamoylphosphate synthetase-negative mutant. METHODS AND RESULTS: The effect of carbon dioxide on the nutritional requirements of Strep. thermophilus DSM20617(T) and its derivative, carbamoylphosphate synthetase-negative mutant A17(DeltacarB), was investigated by cultivating the strain in a chemically defined medium under diverse gas compositions and in milk. The results obtained revealed that CO(2) depletion or carB gene inactivation determined the auxotrophy of Strep. thermophilus for l-arginine and uracil. In addition, the parent strain grew faster than the mutant, even when milk was supplemented with uracil or arginine. CONCLUSIONS: Milk growth experiments underlined that carbamoylphosphate synthetase activity was essential for the optimal growth of Strep. thermophilus in milk. SIGNIFICANCE AND IMPACT OF THE STUDY: The study of the carbon dioxide metabolism in Strep. thermophilus revealed new insights with regard to the metabolism of this species, which could be useful for the optimization of dairy fermentation processes

16S-23S rRNA intergenic spacer region sequence variation in Streptococcus thermophilus and related dairy streptococci and development of a multiplex ITS-SSCP analysis for their identification

The 16S-23S rRNA internal transcribed spacer (ITS) region of several Streptococcus thermophilus strains and some related dairy streptococci, S. macedonicus, S. salivarius and S. bovis, was analysed by sequence analysis. All the Streptococcus species were easily discriminated on the basis of sequence variations principally located upstream and downstream of the region encompassing the double-stranded processing sites and the tRNA(Ala) gene. Comparison between tRNA(Ala) gene sequences highlighted a high level of sequence conservation among the Streptococcus species investigated despite their belonging to separated phylogenetic clusters, i.e. the S. salivarius and S. bovis rRNA groups. A low but significant degree of variability was detected among the S. thermophilus strains, allowing the identification of four different ITS sequences. Similarity analysis of the ITS sequences showed that the Streptococcus species were clustered in two main branches, one containing S. macedonicus and S. bovis strains, and one containing S. thermlophilus and S. salivarius strains. With the aim of developing a rapid tool for the identification of the dairy streptococci species a multiplex ITS-SSCP analysis of two discrete regions within the ITS locus was carried out

Effect of a polyphenol-rich dietary pattern on intestinal permeability and gut and blood microbiomics in older subjects: study protocol of the MaPLE randomised controlled trial.

BACKGROUND: During aging, alterations of the intestinal microbial ecosystem can occur contributing to immunosenescence, inflamm-aging and impairment of intestinal barrier function (increased intestinal permeability; IP). In the context of a diet-microbiota-IP axis in older subjects, food bioactives such as polyphenols may play a beneficial modulatory role. METHODS: MaPLE is a project centered on a randomized, controlled cross-over dietary intervention trial [polyphenol-rich diet (PR-diet) versus control diet (C-diet)] targeted to older people ( 65 60 y) living in a well-controlled setting (i.e. nursing home). The 8-week interventions are separated by an 8-week wash-out period. Three small portions per day of selected polyphenol-rich foods are consumed during intervention in substitution of other comparable products within the C-diet. Biological samples are collected before and after each treatment period to evaluate markers related to IP, inflammation, vascular function, oxidative stress, gut and blood microbiomics, metabolomics. A sample size of 50 subjects was defined based on IP as primary outcome. DISCUSSION: Evidence that increasing the consumption of polyphenol-rich food products can positively affect intestinal microbial ecosystem resulting in reduced IP and decreased translocation of inflammogenic bacterial factors into the bloodstream will be provided. The integration of data from gut and blood microbiomics, metabolomics and other IP-related markers will improve the understanding of the beneficial effect of the intervention in the context of polyphenols-microbiota-IP interactions. Finally, findings obtained will provide a proof of concept of the reliability of the dietary intervention, also contributing to future implementations of dietary guidelines directed to IP management in the older and other at risk subjects. TRIAL REGISTRATION: The trial is registered at (ISRCTN10214981); April 28, 2017

Streptococcis as probiotics

Metagenomics and functional molecular immunology substantiate the interpretation of humans as holobionts, in the sense of functional superorganisms, combining the self and microbes acting in concert to produce phenomena governed by the collective. The association between host and symbionts affects the fitness of the holobiont. Bacteria within the resident communities that colonize mucosal sites outnumber cells of the human body by 10-fold. Such communities are diverse and constituted by numerous taxa; for example, more than 700 taxa are normal inhabitants of the human oropharynx. Some of this population are known to provide significant benefit by counteracting pathogen colonization and by modulating the host immune system. This concept of beneficial bacteria has led to the advent of probiotics as a tool to develop a realistic therapeutic and prophylactic strategy for many inflammatory diseases and infections. In this context, several studies showing the probiotic role of nonpathogenic streptococci both in the modulation of the immune responses through the action on the NF-\u3baB signaling pathways of human epithelial pharyngeal cells, and counteracting the adhesion and the growth of oral pathogenic streptococci, will be presented

Process for obtaining non-allergic propolis

The present invention relates to a process for pre-treating raw propolis comprising at least one allergenic activity substance, which comprises reacting propolis with a probiotic microorganism containing one or more cinnamoyl- esterase activity enzymes to obtain a semisolid propolis derivative substantially without or impoverished of allergenic substances. The present invention also relates to a method of purifying semisolid propolis derivative to obtain a hydroalcoholic hydrodispersible propolis derivative

Small rolling circle plasmids in Bacillus subtilis and related species: Organization, distribution, and their possible role in host physiology

Bacillus subtilis and related species (Bacillus licheniformis, Bacillus pumilus, Bacillus amyloliquefaciens, and Bacillus mojavensis) represent a group of bacteria largely studied and widely employed by industry. Small rolling circle replicating plasmids of this group of bacteria have been intensively studied as they represent a convenient model for genetic research and for the construction of molecular tools for the genetic modification of their hosts. Through the computational analysis of the available plasmid sequences to date, the first part of this review focuses on the main stages that the present model for rolling circle replication involves, citing the research data which helped to elucidate the mechanism by which these molecules replicate. Analysis of the distribution and phylogeny of the small RC plasmids inside the Bacillus genus is then considered, emphasizing the low level of diversity observed among these plasmids through the in silico analysis of their organization and the sequence divergence of their replication module. Finally, the parasitic vs. mutualistic nature of small rolling circle plasmids is briefly discussed

Genetic relationship among Bacillus licheniformis rolling-circle-replicating plasmids and complete nucleotide sequence of pBL63.1, an atypical replicon

The degree of biodiversity among Bacillus licheniformis plasmids and their relation to other Bacillus subtilis group plasmids has been evaluated. To attain this goal we surveyed the diversity and linkage of replication modules in a collection of 21 naturally occurring plasmids of B. licheniformis strains, isolated from different geographical areas. On the basis of rep gene sequence analysis it was possible to group the B. licheniformis plasmids rep genes in two main cluster. Comparison with known rep genes from Bacillus rolling-circle-replicating (RCR) plasmids revealed the presence in B. licheniformis plasmids of replication genes with a DNA sequence peculiar to B. licheniformis species together with rep genes with a very high sequence similarity to B. subtilis plasmids. Furthermore, the molecular organization of an atypical replicon, pBL63.1, was shown. This plasmid did not display any significant similarity with known Bacillus RCR plasmids. The complete nucleotide sequence evidenced a replication module with an unexpected similarity with Rep proteins from RCR plasmids of bacterial species phylogenetically distantly related to Bacillus. pBL63.1 represents an exception to the low-level diversity hypothesis among Bacillus RC replicons

Integrated approaches for the production of vanillin

Vanillin is the molecule responsible for the well-known vanilla aroma, and therefore one of the most used flavour components in the food and cosmetic industries. Vanillin is mostly produced via a chemical process, with only a small fraction extracted from natural sources, namely, the bean of the orchid Vanilla planifolia. The consumer demand for natural vanillin highly exceeds the amount of vanillin extracted by plant sources and new methods for the production of natural vanillin have been attempted. Biotransformation of natural substrates into vanillin is an alternative way to produce the natural flavour. Ferulic acid can be obtained by hydrolysis of the lignin fraction of plant biomasses and converted into vanillin using engineered microorganisms. Our work has been focused on solving the major challenges in obtaining preparative bioprocesses are: the availability of methods for hydrolysis and recovery of ferulic acid from biomasess, the construction of stable and productive engineered microorganisms with high tolerance towards the vanillin produced, the optimization of fermentation/biotransformation, and finally efficient protocols for vanillin recovery. Examples from our work will be presented with regards to different strategies for identifying an integrated approach for biotechnological vanillin production

Use of a composition comprising microorganisms to increase the intestinal production of butyric acid, folic acid or niacin and/or decrease the intestinal production of succinic acid

The present invention relates to the use of a composition comprising bacteria to increase the intestinal production of butyric acid, folic acid or niacin and/or to decrease the intestinal production of succinic acid. Moreover, the present invention relates to the use of said composition for the treatment and/or prevention of an intestinal butyrate- and/or succinate- dependent pathological condition. In particular, for the treatment and/or the prevention of intestinal inflammation, diarrhoea, ulcerative colitis or intestinal colopathies