Draft Genome Sequence of Lactobacillus plantarum Lp90 Isolated from Wine

Contains fulltext : 155072.pdf (publisher's version ) (Open Access)Here, we describe the draft genome sequence and annotation of Lactobacillus plantarum strain Lp90, the first sequenced genome of a L. plantarum strain isolated from wine. This strain has a noticeable ropy phenotype and showed potential probiotic properties. The genome consists of 3,324,076 bp (33 contigs) and contains 3,155 protein coding genes, 34 pseudogenes, and 84 RNA genes

Development of new microalgae-based sourdough "crostini": functional aspects of Arthrospira platensis (spirulina) addition

The aim of this work was to evaluate the influence of Arthrospira platensis F&M-C256 (spirulina) incorporation on the nutritional and functional properties of “crostini”, a leavened bakery product largely consumed in Italy and Europe. Sourdough was used as leavening and fermentation agent and three concentrations of A. platensis F&M-C256 were tested: 2%, 6% and 10% (w/w). Despite a lower volume increase compared to the control, the A. platensis F&M-C256 “crostini” doughs reached a technological appropriate volume after fermentation. At the end of fermentation, no significant differences in microorganisms concentrations were observed. A. platensis F&M-C256 “crostini” showed higher protein content compared to the control. Considering the European Commission Regulation on nutritional claims, “crostini” incorporated with 6% and 10% biomass can be claimed to be a “source of protein”. Six and ten percent A. platensis “crostini” also presented significantly higher antioxidant capacity and phenolics. A significantly lower value of in vitro dry matter and protein digestibility between A. platensis F&M-C256 “crostini” and the control was found. The overall acceptability decreased with increasing A. platensis F&M-C256 addition. The combination of spirulina biomass addition and the sourdough technology led to the development of a novel microalgae-based bakery product with nutritional and functional featuresinfo:eu-repo/semantics/publishedVersio

Antimicrobial activity of Lactobacillus plantarum strains and antimicrobial properties of L. plantarum small heat shock proteins

The aim of this study was to investigate Lactobacillus plantarum strains possessing antimicrobial features to be proposed as potential bioagents and biopreservant stains that could prevent the growth of pathogenic bacteria in fermented food. A total of 85 Lactobacillus plantarum strains, including strains overproducing small heat shock proteins, were investigated for their antimicrobial activity against the pathogenic bacteria Escherichia coli O157:H7, Staphylococcus aureus, Listeria monocytogenes and Salmonella enterica. Firstly, the antimicrobial effect was evaluated using over-night cultures (ONC) of lactobacilli by agar spot test. The antagonistic effects of L. plantarum strains against pathogens were detected measuring the growth inhibition halos on plates. All strains showed significant antibacterial activity and we classified L. plantarum strains as no, mild, strong and very strong inhibiting strain when inhibitions zone of 1 mm, 2 mm, 2-5 mm and more than 5 mm were produced. Subsequentially, 15 strains showing strong and very strong antimicrobial activity were selected and their cell-free supernatant (CFS) was harvested and used for agar diffusion and microdilution bioassays over an incubation time of 24 h at 30 °C, in order to investigate the substances determining the antimicrobial ability. Overall, the results showed an interesting antagonism depending both on L. plantarum strain analysed and pathogens bacteria tested. Moreover, antimicrobial activity was observed by L. plantarum strains overproducing small heat shock proteins. The applications of L. plantarum strains exhibiting antimicrobial activity need to be considered as safety bio-alternative to traditional antibiotics used against human infection and to chemical substances used in the food processing

Probiotic survival in symbiotic yogurt-like cereal-based beverage

The scientific literature and market trends testify to the growing emphasis on the development of dairy-like vegetable based products, including food matrices based on fruit, vegetables and cereals, able to meet the needs of consumers allergic/intolerant, on cholesterol-restricted diets, and/or vegans. Together with the formulations based on soy flour, yogurt-like products produced from cereal flours, have been receiving increasing attention due to the good balance of texture, flavor, and nutritional properties in the final product. As substitutes of dairy productions, the corresponding non-dairy foods yogurt represent a novel alternative for the consumption of probiotic bacteria. In order to produce yogurt-like cereal-based beverages, a mixture of rice, barley, and oat flours and concentrated red grape must were used. In addition to standard formulation, we prepared a β-glucans enriched beverage using a flour of barley selected for its β-glucans content (12 g of β-glucans per 100 g of flour). β-glucans have been reported to be highly fermentable by the intestinal microbiota in the caecum and colon, and can enhance both growth rate and lactic acid production of microbes isolated from the human intestine. Throughout the technological phases, a commercial yogurt starter cultures and a selected strain of Lactobacillus plantarum were separately used to perform lactic acid fermentation (30 °C, 8 hours). During the storage at 4 °C, we assessed the survival of 7 probiotic strains ( Lactobacillus acidophilus LA5, L. plantarum CECT 8328, Lactobacillus johnsonii CECT 289, Lactobacillus fermentum CECT 8448, Lactobacillus reuteri CECT 925, Lactobacillus paracasei subsp. paracasei LC-01 , L. plantarum WCFS1) in the standard yogurt-like cereal-based beverage and in β-glucans enriched beverage (symbiotic yogurt-like cereal-based beverage)

Antimicrobial activity of Lactobacillus plantarum strains and antimicrobial properties of L. plantarum small heat shock proteins

The aim of this study was to investigate Lactobacillus plantarum strains possessing antimicrobial features to be proposed as potential bioagents and biopreservant stains that could prevent the growth of pathogenic bacteria in fermented food. A total of 85 Lactobacillus plantarum strains, including strains overproducing small heat shock proteins, were investigated for their antimicrobial activity against the pathogenic bacteria Escherichia coli O157:H7, Staphylococcus aureus, Listeria monocytogenes and Salmonella enterica. Firstly, the antimicrobial effect was evaluated using over-night cultures (ONC) of lactobacilli by agar spot test. The antagonistic effects of L. plantarum strains against pathogens were detected measuring the growth inhibition halos on plates. All strains showed significant antibacterial activity and we classified L. plantarum strains as no, mild, strong and very strong inhibiting strain when inhibitions zone of 1 mm, 2 mm, 2-5 mm and more than 5 mm were produced. Subsequentially, 15 strains showing strong and very strong antimicrobial activity were selected and their cell-free supernatant (CFS) was harvested and used for agar diffusion and microdilution bioassays over an incubation time of 24 h at 30 °C, in order to investigate the substances determining the antimicrobial ability. Overall, the results showed an interesting antagonism depending both on L. plantarum strain analysed and pathogens bacteria tested. Moreover, antimicrobial activity was observed by L. plantarum strains overproducing small heat shock proteins. The applications of L. plantarum strains exhibiting antimicrobial activity need to be considered as safety bio-alternative to traditional antibiotics used against human infection and to chemical substances used in the food processing

Comparative genome analysis reveals strains specific gene clusters involved in exopolysaccharides biosynthesis in Lactobacillus plantarum

Several lactic acid bacteria (LAB) produce capsular and secreted forms of exopolysaccharides (EPS) (Remus et al., 2012). The EPS production is correlated to the presence of specific gene clusters (eps/cps) which exhibit a conserved modular organization and include genes encoding both regulatory factors and enzymes involved in EPS biosynthesis, polymerization and secretion, including glycosyl-transferases, which are responsible for the assembly of the characteristic EPS-repeating unit. The Lactobacillus plantarum WCFS1 genome encodes 4 cps clusters of genes that are associated with surface polysaccharide production. The cps2A-J and cps4A-J clusters encode all functions required for capsular polysaccharide formation, while the cps1A-I and cps3A-J clusters lack genes encoding chain-length control functions and a priming glycosyl-transferase (Remus et al., 2012). L. plantarum Lp90 exhibited a ropy phenotype which was associated to its capacity to produce EPS. The genetic basis of EPS production was investigated by identification, sequencing and comparative analysis of genes clusters involved in EPS biosynthesis with other L. plantarum genomes. It was found that the cluster 4 (cps4) is the most conserved, while the cluster 3 presents high homology with cps3 of WCFS1, ST-III and ATCC 14917 L. plantarum strains. Conversely, cluster 1 (cps1) is fully present only in L. plantarum JDM1, while the first genes of cluster 2 are homologous to the cps2A-E genes of other L. plantarum. The remaining genes of cluster 2 are homologous to proteins of Lactobacillus fabifermentans T30PCM01, probably involved in the exopolysaccharides biosynthesis. This feature makes unique the organization of cps clusters L. plantarum Lp90 and may explain the ropy phenotype of this strain

Zebrafish gut colonization by mCherry-labelled lactic acid bacteria

A critical feature of probiotic microorganisms is their ability to colonize the intestine of the host. Although the microbial potential to adhere to the human gut lumen has been investigated in in vitro models, there is still much to discover about their in vivo behaviour. Zebrafish is a vertebrate model that is being widely used to investigate various biological processes shared with humans. In this work, we report on the use of the zebrafish model to investigate the in vivo colonization ability of previously characterized probiotic lactic acid bacteria. Lactobacillus plantarum Lp90, L. plantarum B2 and Lactobacillus fermentum PBCC11.5 were fluorescently tagged by transfer of the pRCR12 plasmid, which encodes the mCherry protein and which was constructed in this work. The recombinant bacteria were used to infect germ-free zebrafish larvae. After removal of bacteria, the colonization ability of the strains was monitored until 3 days post-infection by using a fluorescence stereomicroscope. The results indicated differential adhesion capabilities among the strains. Interestingly, a displacement of bacteria from the medium to the posterior intestinal tract was observed as a function of time that suggested a transient colonization by probiotics. Based on fluorescence observation, L. plantarum strains exhibited a more robust adhesion capability. In conclusion, the use of pRCR12 plasmid for labelling Lactobacillus strains provides a powerful and very efficient tool to monitor the in vivo colonization in zebrafish larvae and to investigate the adhesion ability of probiotic microorganism

Draft genome sequence and annotation of Lactobacillus plantarum strain Lp90 isolated from Apulian (Italy) wine

Lactobacillus plantarum is a facultative heterofermentative lactic acid bacteria (LAB), found in many different ecological niches. L. plantarum is widely used as starter and probiotic in many food processes. Some strains are claimed to provide health benefits and are marketed as probiotics. Here we report the draft genome sequence and annotation of L. plantarum strain Lp90 previously isolated from Nero di Troia, a typical Apulian (South of Italy) wine. L. plantarum strain Lp90 has a noticeable ropy phenotype, which was ascribed to its capacity to over-produce exopolysaccharides (EPS). It is the first L. plantarum genome coming from a strain of wine origin sequenced. This strain was already characterized in a previous study describing the phenotypic and genomic diversity of L. plantarum strains isolated from various environmental niches and in three studies on Lp90 genes coding for small heat shock proteins. The genome of L. plantarum strain Lp90 consists of 3,324,076 bp in 33 contigs with a CG content of 44.32%. The genome size and the CG content are comparable those of published L. plantarum genomes (http://www.ncbi.nlm.nih.gov/genome/genomes/1108). Among the 3,273 predicted genes, 3,155 were protein coding genes, 34 were identified to be pseudo-genes, while 84 were RNA coding genes (70 tRNAs and 14 rRNAs). The presence of a signal peptide was predicted for 311 proteins. Transmembrane region analysis revealed 869 proteins containing transmembrane helices. The availability of the draft genome sequence of Lp90 represents the base to investigate some peculiar features of this strain, such as the EPS production and the ability to tolerate stress to the wine environment