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Aims: This study was performed to ascertain the immunomodulatory effect of Lactobacillus paracasei strains. These strains were also genetically characterized. Methods and Results: The strains were genetically differentiated by using the fluorescent-amplified fragment length polymorphism technique, which led to the identification of several molecular markers unique to each strain. To determine the immunomodulatory properties, we evaluated the effect of strains on dendritic cell maturation, dextran uptake, ability to induce proliferation of allogenic T cells and cytokine secretion. The results indicated that all the strains stimulated phenotypic maturation of dendritic cells (DCs), but they acted differently on DCs in relation to the other tested properties; notably, a different effect on cytokine secretion was detected. Conclusions: The results of this study revealed different immunomodulatory properties of strains of the species Lact. paracasei. Strain IMPC 4.1 showed an interesting anti-inflammatory ability. Probiotic strains IMPC 2.1 and LMG P-17806 were characterized by a similar and intermediate ability to induce cytokine secretion in contrast to the very low ability of strain LMG 23554. Significance and Impact of Study: Our results confirm that each single strain of a bacterial species appears to influence the immune system in a peculiar manner. The evaluation of the different types and/or levels of cytokines whose secretion is induced by each strain could be relevant to define its pro- or anti-inflammatory properties and its more appropriate clinical use. [ABSTRACT FROM AUTHOR]

To evaluate the positive influence of the probiotic strain Lactobacillus paracasei LMGP22043 carried by artichokes into the human gut with special reference to faecal bacterial balance, short-chain fatty acid concentrations and enzyme activities in a randomized, double-blind human trial in comparison with probiotic-free artichokes (control). Twenty subjects were randomized into two groups, which consumed daily 180 g of the artichoke product (probiotic or control) during two 15-day study periods (periods 1 and 2) separated by a 15-day washout in a crossover manner. Faecal samples were subjected to microbiological and biochemical analyses, and a strain-specific PCR was performed to monitor the probiotic strain. The probiotic strain, transported by the vegetable matrix, transiently colonized the gut of 17/20 subjects (median 6·87 log CFU g faeces), antagonized Escherichia coli and Clostridium spp. and increased the genetic diversity of lactic population based on REP-PCR profiles, mainly after period 1. The probiotic L. paracasei LMGP22043 successfully colonized the human gut and positively influenced faecal bacteria and biochemical parameters. The association of the probiotic L. paracasei with a food carrier rich in fibre can represent a new strategy for favouring a daily supply of probiotics and attracting more consumers to vegetable food fortified with probiotic strains. [ABSTRACT FROM AUTHOR]

Explores the production of acetic acid via arabinose fermentation using Lactobacillus plantarum in sourdough. Extraction of pentosans from a wheat flour slurry; Estimation of lactic acid bacteria cell yield; Importance of the study on the bread industry.

Pseudomonas syringae pv. ciccaronei strain NCPPB2355 was found to produce a bacteriocin inhibitory against strains of Ps. syringae subsp. savastanoi, the causal agent of olive knot disease. Treatments with mitomycin C did not substantially increase the bacteriocin titre in culture. The purification of the bacteriocin obtained by ammonium sulphate precipitation of culture supernatant fluid, membrane ultrafiltration, gel filtration and preparative PAGE, led to the isolation of a high molecular weight proteinaceous substance. The bacteriocin analysed by SDS-PAGE revealed three protein bands with molecular weights of 76, 63 and 45 kDa, respectively. The bacteriocin was sensitive to heat and proteolytic enzymes, was resistant to non-polar organic solvents and was active between pH 5·0–7·0. Plasmid-DNA analysis of Ps. syringae ciccaronei revealed the presence of 18 plasmids; bacteriocin-negative variants could not be obtained by cure experiments. [ABSTRACT FROM AUTHOR]