Abstract Background Lactic acid bacteria of the genus Lactobacillus and Bifidobacterium are one most important health promoting groups human intestinal microbiota. Their protective role within gut consists in out competing invading pathogens for ecological niches metabolic substrates. Among features necessary to provide benefits, commensal microorganisms must have ability adhere cells consequently colonize gut. Studies on mechanisms mediating adhesion lactobacilli showed that factors...

Lactococcus lactis is a lactic acid bacterium (LAB), generally recognized as safe, and has been widely used in the food industry, especially fermented dairy products. Numerous studies have evaluated technological probiotic properties of lactococci; however, few reported characteristics L. strains isolated from In this work, potential, including survival simulated gastric juice, tolerance to bile salts, hydrophobicity, auto- co-aggregation, was natural whey starter cultures. The results...

<title>Abstract</title> In the last few years, probiotics have gained much attention within medical, pharmaceutical, and food fields, given health benefits provided by their consumption. They include several lactic acid bacteria (LAB) species, mostly belonging to genera <italic>Lactobacillus</italic>, <italic>Lactococcus</italic>, <italic>Streptococcus</italic>. Postbiotics are bioactive compounds (organic acids, short-chain fatty enzymes, neurotransmitters) produced bacterial fermentation...

In southern Italy, some artisanal farms produce mozzarella and caciocavallo cheeses by using natural whey starter (NWS), whose microbial diversity is responsible for the characteristic flavor texture of final product. We studied community NWS cultures cow's milk (NWSc) production buffalo's (NWSb) mozzarella, both from farms. Bacterial identification at species strain level was based on an integrative strategy, combining culture-dependent (sequencing 16S rDNA, species/subspecies-specific...

ABSTRACT We report the characterization of ccpA gene Lactobacillus plantarum , coding for catabolite control protein A. The is linked to pepQ gene, encoding a proline peptidase, in order ccpA-pepQ with two genes transcribed tandem from same strand as distinct transcriptional units. Two transcription start sites corresponding functional promoters were found, expression upstream promoter being autogenously regulated through catabolite-responsive element ( cre ) sequence overlapping +1 site....

Abstract The aim of this study was to identify genes involved in biofilm development the probiotic lactic acid bacterium Lactobacillus plantarum . ability L. LM3 and some derivative mutant strains form has been investigated. Biofilm microtitre plate assays showed that LM3‐2, carrying a null mutation ccpA gene, coding CcpA master regulator, partially impaired production compared wild type (LM3). Moreover, we found three genome, hereby named flmA , flmB flmC whose deduced amino sequences show...

Collagen is a target of pathogens for adhesion, colonization, and invasion host tissue. Probiotic bacteria can mimic the same mechanism as used by in colonization process, expressing cell surface proteins that specifically interact with extracellular matrix component proteins. The capability to bind collagen expressed several Lactobacillus isolates, including some plantarum strains. In this study we report involvement L. EnoA1 alfa-enolase type I (CnI) binding. By adhesion assays, show...

Lactic acid bacteria (LAB) are widely used in food industry and their growth performance is important for the quality of fermented product. During industrial processes changes temperature may represent an environmental stress to be overcome by starters non-starters LAB. Studies on adaptation heat shock have shown involvement chaperon system-proteins various gram-positive bacteria. The corresponding operons, namely dnaK groESL controlled a negative mechanism involving HrcA repressor protein...

ABSTRACT A newly identified bglH gene coding for a phospho-β-glucosidase of Lactobacillus plantarum was isolated and expressed in Escherichia coli . The sequence analysis the cloned DNA fragment showed an open reading frame encoding 480-amino-acid protein with calculated molecular mass 53 kDa. shown to be on monocistronic transcriptional unit. Its transcription repressed 10-fold L. cells grown glucose compared β-glucoside salicin as sole carbon source. catabolite-responsive element (CRE)...

An in vivo footprinting analysis of the ilvIH regulatory region Escherichia coli showed that transcription activator Lrp binds to six sites, scattered over 250 bp upstream transcriptional start point. When Lrp-mediated activation was impaired by presence exogenous leucine, only one promoter-distal site (site 2) partially protected binding. Equilibrium dialysis experiments formation an Lrp-leucine complex vitro. These results suggest leucine negatively affects because its interaction with...

The protein MucR from Brucella abortus has been described as a transcriptional regulator of many virulence genes. It is member the Ros/MucR family comprising proteins that control expression genes important for successful interaction α-proteobacteria with their eukaryotic hosts. Despite clear evidence role in repressing genes, no study carried out so far demonstrating direct this promoter its target gene babR encoding LuxR-like virB In study, we show first time ability to bind...

A newly-identified bglGPT operon of Lactobacillus plantarum was isolated and expressed in Escherichia coli. The sequence analysis the cloned DNA fragment showed three open reading frames encoding (i) a 237-amino acid protein (BglG), (ii) 577-amino (BglP) (iii) 486-amino (BglT). BglG, BglP BglT were shown to be homologous BglG family transcriptional antiterminators, permeases phosphoenolpyruvate-dependent phosphotransferase system beta-glucosidases, respectively. Complementation E. coli...

Multi-functional surface proteins have been observed in a variety of pathogenic bacteria, where they mediate host cell adhesion and invasion, as well commensal bacterial species, were positive interaction with the host. Among these proteins, some glycolytic enzymes, expressed on surface, can bind human extracellular matrix components (ECM). A major target for them is collagen, an abundant glycoprotein connective tissues. We previously shown that enolase EnoA1 Lactobacillus plantarum, one...

Multi-drug resistant tuberculosis (MDR-TB) represents a major health problem worldwide. Drug efflux and the activity of transporters likely play important roles in development drug-tolerant drug-resistant mycobacterial phenotypes. This study is focused on action pump as mechanism drug resistance. Previous studies demonstrated up-regulation TetR-like transcriptional regulator MSMEG_3765 Mycobacterium smegmatis its ortholog Rv1685c ( Mtb ) acid-nitrosative stress conditions. MSMEG-3765...

The Bacillus subtilis BofA protein is involved in regulation of pro-σ K processing the mother cell during late stages sporulation. A computer analysis amino acid sequence indicates that it an integral membrane protein. To determine topology protein, a series gene fusions bofA with lacZ or phoA reporter genes Escherichia coli were analysed. topological model two membrane-spanning segments, and N- C-terminal domains located region between inner outer membranes surrounding forespore presented....

Evidence is presented that expression of the cotH gene, whose product required for correct assembly Bacillus subtilis spore coat, negatively controlled by transcriptional regulator GerE. Mutations in GerE-box, present promoter region, increased this which also remained elevated during late stages sporulation, when wild-type cells normally turned off. Such alterations did not significantly affect coat structure or function but caused accumulation CotC molecules mother cell compartment, most...

Lactobacillus plantarum is one of the most predominant species in human gut microbiota healthy individuals. We have previously characterized some probiotic features L. LM3, as high resistance to different stress, binding ability toward extracellular matrix proteins and plasminogen immunomodulatory role surface expressed adhesin EnoA1. also identified flmA, flmB flmC genes, coding for putative named FlmA, FlmB FlmC, whose null mutations partially impaired biofilm development; LM3⁻6 strain,...

Drug resistance is one of the most difficult challenges facing tuberculosis (TB) control. efflux among mechanisms leading to drug resistance. In our previous studies, we partially characterized ABC-type MSMEG-3762/63 pump in Mycobacterium smegmatis, which shares high percentage identity with Rv1687/86c pump. was shown have extrusion activity for rifampicin and ciprofloxacin, used first second-line anti-TB treatments. Moreover, described functional role TetR-like MSMEG-3765 protein as a...

The leucine-responsive regulatory protein (Lrp) is a DNA binding that affects, either positively or negatively, the expression of several E. coli genes. ilvIH operon regulated by Lrp and leucine counteracts this effect reducing 5- to 10-fold efficiency transcription. An investigation mechanism transcription activation indicated that: (i) stereospecific alignment between promoter cis-acting sequence upstream it required for activation; (ii) correct distance adjacent needed counteract positive...