Search results for "lactobacillus"
showing 10 items of 353 documents
Isolation, Identification and Investigation of Fermentative Bacteria from Sea Bass (Dicentrarchus labrax): Evaluation of Antifungal Activity of Ferme…
2020
During fish production processes, great amounts of by-products are generated, representing &asymp
Evaluation of fermentation assisted by Lactobacillus brevis POM, and Lactobacillus plantarum (TR-7, TR-71, TR-14) on antioxidant compounds and organi…
2020
Abstract The impact of fermentation assisted by four different lactic acid bacteria (LAB) on polyphenols, carotenoids, organic acids, and antioxidant capacity of orange-juice milk based beverages was evaluated. Lactobacillus brevis POM, and Lactobacillus plantarum (TR-7, TR-71, TR-14) were used to promote the fermentation of the beverages for 72 h at 37 °C. The bacteria population increased with the elapse of fermentation period, except for beverages inoculated with L. plantarum TR-7. After fermentation period, total polyphenols, total carotenoids and total antioxidant capacity were increased compared to the control ones (non-fermented). Two phenolic acids (DL-3-phenylactic acid and 3–4-dih…
Noroviral P-Particles as an In Vitro Model to Assess the Interactions of Noroviruses with Probiotics
2014
Noroviruses (NoVs) are the main etiologic agents of acute epidemic gastroenteritis and probiotic bacteria have been reported to exert a positive effect on viral diarrhea. The protruding (P) domain from NoVs VP1 capsid protein has the ability to assemble into the so-called P-particles, which retain the binding ability to host receptors. We purified the P-domains from NoVs genotypes GI.1 and GII.4 as 6X(His)-tagged proteins and determined that, similar to native domains, they were structured into P-particles that were functional in the recognition of the specific glycoconjugated receptors, as established by surface plasmon resonance experiments. We showed that several lactic acid bacteria (pr…
The Agr communication system provides a benefit to the populations of Listeria monocytogenes in soil
2014
International audience; In this study, we investigated whether the Agr communication system of the pathogenic bacterium Listeria monocytogenes was involved in adaptation and competitiveness in soil. Alteration of the ability to communicate, either by deletion of the gene coding the response regulator AgrA (response-negative mutant) or the signal pro-peptide AgrD (signal-negative mutant), did not affect population dynamics in soil that had been sterilized but survival was altered in biotic soil suggesting that the Agr system of L. monocytogenes was involved to face the complex soil biotic environment. This was confirmed by a set of co-incubation experiments. The fitness of the response-negat…
In vitro evaluation of bacteriocinlike inhibitory substances produced by lactic acid bacteria isolated during traditional sicilian cheese making
2016
Bacteriocins are antimicrobial proteins produced by bacteria that inhibit with a bactericidal or bacteriostatic mode of action, the growth of other bacteria. Many lactic acid bacteria (LAB) produce a high diversity of different bacteriocins. Bacteriocinogenic LAB are generally recognized as safe (GRAS) and useful to control the frequent development of pathogens and spoilage microorganisms; for this reason they are commonly used as starter cultures in food fermentations. In this study, the authors describe the results of a screening on 699 LAB isolated from wooden vat surfaces, raw milk and traditional Sicilian cheeses, for the production of bacteriocin-like inhibitory substances (BLIS), by …
Ultrasound-Assisted Lactic Acid Fermentation of Bakraei (Citrus reticulata cv. Bakraei) Juice: Physicochemical and Bioactive Properties
2022
In this study, ultrasonication (US) (50 W, 30 kHz, 1–6 min) was used to increase the efficiency of Limosilactobacillus reuteri PTCC 1655 fermentation process (37 °C; 30 h) of Bakraei juice. Total sugars, pH, Brix, organic acids, vitamin C, polyphenols, antioxidant activity, α-amylase inhibition and anti-inflammatory properties were measured during the fermentation period. The results showed that by increasing the ultrasound time up to 5 min, pH, vitamin C, citric acid, and polyphenolic compounds decreased, while lactic acid, antioxidant capacity, α-amylase inhibition and anti-inflammatory properties were increased. When the ultrasound time was increased up to 6 min, co…
Identification of Lactobacilli from Deep Carious Lesions by Means of Species-Specific PCR and MALDI-TOF Mass Spectrometry
2014
SUMMARY Background: The aim of the present study was to compare MALDI-TOF results for the identification of 87 lactobacilli, isolated from soft or hard carious dentin from 70 first molars of 7- to 8-year-old children with those obtained by species-specific PCR. Methods: The 87 isolates were analyzed by MALDI-TOF MS (Microflex LT, MALDI Biotyper 3.0, Bruker Daltonik, Bremen, Germany), using a reference data base of 4110 strains including > 90 lactobacillus species. For the identification with species-specific PCR, oligonucleotide primers (16S rRNA) specific for L. casei, L. paracasei, L. rhamnosus, L. gasseri, L. plantarum, and L. acidophilus were used; type strains served as controls. The P…
Lactobacillus acidophilus La5 and Bifidobacterium lactis Bb12 cell surface hydrophobicity and survival of the cells under adverse environmental condi…
2012
Abstract Changes in the cell surface hydrophobicity (CSH) of probiotic bacteria Lactobacillus acidophilus La5 and Bifidobacterium lactis Bb12 and the survival of these cells were examined in response to varied cultivation conditions and adverse environmental conditions. An inverse linear relationship (P < 0.01) was detected between the CSH of intact L. acidophilus La5 and B. lactis Bb12 and survival of cells subjected to subsequent freezing/thawing, long-term storage or exposure to mineral and bile acids. The observed relationships were supported by significant correlations between the CSH and changes in composition of the cell envelopes (proteins, lipids and carbohydrates) of L. aci…
Membrane fatty acid composition and fluidity are involved in the resistance to freezing of Lactobacillus buchneri R1102 and Bifidobacterium longum R0…
2015
International audience; Determinations of membrane fatty acid composition and fluidity were used together with acidification activity and viability measurements to characterize the physiological state after freezing of Lactobacillus buchneri R1102 and Bifidobacterium longum R0175 cells harvested in the exponential and stationary growth phases. For both strains, lower membrane fluidity was achieved in cells harvested in the stationary growth phase. This change was linked to a lower unsaturated-to-saturated fatty acid ratio for both strains and a higher cyclic-to-saturated fatty acid ratio for L. buchneri R1102 alone. These membrane properties were linked to survival and to maintenance of aci…
Comparative survey of putrescine production from agmatine deamination in different bacteria
2008
This article aims to study putrescine production in Lactobacillus hilgardii strain X1B, an agmatine degrader isolated from wine, and to compare it with three other different species, previously reported as putrescine producers from agmatine: Pseudomonas aeruginosa PAO1, Enterococcus faecalis ATCC11700 and Bacillus cereus CECT 148T. The effect of different biogenic amines, organic acids, cofactors, amino acids and sugars on putrescine production was evaluated. In some cases, a similar effect was found in all the strains studied but the magnitude differed. Arginine, glucose and fructose showed an inhibitory effect, whereas the presence of agmatine induced the production of putrescine in all m…