Littérature scientifique sur le sujet « Lactobacillu »
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Articles de revues sur le sujet "Lactobacillu"
1
Gaglio, Raimondo, Antonio Alfonzo, Noemi Polizzotto, Onofrio Corona, Nicola Francesca, Giuseppe Russo, Giancarlo Moschetti et Luca Settanni. « Performances of Different Metabolic Lactobacillus Groups During the Fermentation of Pizza Doughs Processed from Semolina ». Fermentation 4, no 3 (3 août 2018) : 61. http://dx.doi.org/10.3390/fermentation4030061.
Texte intégralRésumé :
The main hypothesis of this work is that facultative and obligate heterofermentative Lactobacillus species can differently impact the final characteristics of pizza. The objective was to evaluate separately the behavior of the facultative heterofermentative species (FHS), such as Lactobacillus sanfranciscensis, Lactobacillu brevis, and Lactobacillus rossiae, and to obligate the heterofermentative species (OHS), including Lactobacillus plantarum, Lactobacillus graminis, and Lactobacillus curvatus, in the sourdoughs to be used for pizza production. The production of the experimental pizzas was carried out with semolina (Triticum turgidum L. ssp. durum). The acidification process, followed by pH, total titratable acidity (TTA), and lactic acid bacteria (LAB) development indicated for all of the experimental trials kinetics is comparable to those of the controls. The fermentation quotient of the FHS trial was particularly higher than that of the other trials, including the control production performed with a sourdough inoculum used in an artisanal bakery. The dominance of the added strains indicated the clear persistence of L. sanfranciscensis PON 100336, L. brevis 200571, and L. plantarum PON 100148 in the obligate–facultative heterofermentative species (OFHS) trial. The pizzas were baked without seasoning in order to investigate weight loss, color, morphology, and a generation of volatile organic compounds (VOCs). The data showed the differences among trials regarding the inocula. Eight classes of VOCs were detected in the pizza samples with aldehydes, esters, alcohols, and acids as major compounds. The sensory attributes were significantly different for the judges and the pizzas. The multivariate statistical approach found marked differences among the trials. The results indicated that the application of mixed cultures of the facultative heterofermentative species of Lactobacillus determined high quality pizzas.
2
Chen, Chunfei, Leilei Yu, Fengwei Tian, Jianxin Zhao et Qixiao Zhai. « Identification of Novel Bile Salt-Tolerant Genes in Lactobacillus Using Comparative Genomics and Its Application in the Rapid Screening of Tolerant Strains ». Microorganisms 10, no 12 (30 novembre 2022) : 2371. http://dx.doi.org/10.3390/microorganisms10122371.
Texte intégralRésumé :
Under bile salt treatment, strains display significant differences in their tolerance ability, suggesting the existence of diverse resistance mechanisms in Lactobacillus; however, the genes involved in this protective process are not fully understood. In this study, novel target genes associated with bile salt tolerance in Lactobacillus were identified using comparative genomics for PCR detection and the rapid screening of tolerant strains. The bile salt tolerance of 107 lactobacilli isolated from different origins was assessed, and 26 strains with comparatively large differences were selected for further comparative genomic analysis. Tolerant strains had 112 specific genes that were enriched in the phosphotransferase system, the two-component system, carbohydrate metabolism, and the ATP-binding cassette transporter. Six genes from Lactobacillus were cloned into the inducible lactobacillal expression vector pSIP403. Overexpression in the host strain increased its tolerance ability by 11.86–18.08%. The novel genes identified here can be used as targets to design primers for the rapid screening of bile salt-tolerant lactobacilli. Altogether, these results deepen our understanding of bile salt tolerance mechanisms in Lactobacillus and provide a basis for further rapid assessments of tolerant strains.
3
Bilkova, A., H. Kinova Sepova, M. Bukovsky et L. Bezakova. « Antibacterial potential of lactobacilli isolated from a lamb ». Veterinární Medicína 56, No. 7 (11 août 2011) : 319–24. http://dx.doi.org/10.17221/1583-vetmed.
Texte intégralRésumé :
The antimicrobial properties of three potential probiotic strains of lactobacilli isolated from a lamb (Lactobacillus murinus C, Lactobacillus mucosae D and Lactobacillus reuteri E) were studied using the streak line method and the agar well diffusion assay. The probiotic lactobacilli strains Lactobacillus rhamnosus ATCC 53103, Lactobacillus reuteri ATCC 55730, Lactobacillus reuteri ATCC 55845 and Lactobacillus plantarum DSM 9843 were used for comparison. Using the streak line method the inhibitory activity of lactobacilli products towards ten Gram-positive and Gram-negative potential pathogenic bacteria under different cultivation conditions (anaeorobic or microaerobic preincubation of lactobacilli for 24 h or 48 h) was tested. The strongest inhibitory activity was demonstrated by the Lactobacillus reuteri E strain. The most sensitive strains to the antimicrobial activity of lactobacilli were Yersinia enterocolitica clinical isolate (19.9 ± 6.8 mm) and Listeria monocytogenes ATCC 51774 (17.7 ± 6.0 mm) after microaerobic and anaerobic preincubation, respectively. Generally, microaerobic conditions and longer preincubation of lactobacilli resulted in stronger inhibition of target bacteria. The inhibitory activity of lactobacilli towards selected lactobacilli strains was also tested. Only low inhibition of growth was observed. In the agar well diffusion assay the inhibitory effect of natural and modified lactobacilli culture cell-free supernatants, obtained from MRS broth cultures, on Staphylococcus aureus ATCC 6538 growth was determined. Supernatants were modified by heat (10 min/60 °C; 60 min/100 °C) and protease treatment and neutralization of pH. Neutralization elicited the most significant impact on the activity of supernatants and resulted in total loss of activity. After all other modifications supernatants retained some residual activity. The highest inhibitory activity was observed for the cell-free supernatant produced by Lactobacillus mucosae D.
4
Ghazaei, Ciamak. « Isolation and Characterization of Lactic Acid Bacteria From Milk and Their Effects on the Pathogenic Bacteria ». Research in Molecular Medicine 8, no 4 (26 octobre 2020) : 189–200. http://dx.doi.org/10.32598/rmm.8.4.4.
Texte intégralRésumé :
Background: Probiotics are “live microbial cells” that are beneficial for human and animal health. Lactobacilli are such a diverse group of bacteria with similar metabolic and physiological characteristics, and constitute important and beneficial gut microflora. During carbohydrate fermentation, lactobacilli produce lactic acid as an end product in metabolism. Hence, lactobacilli have high significance to be used as probiotics in the food industry, because of their acidifying properties. Also, lactobacilli are considered “safe”, owing to their ubiquitous presence in the food. Many researchers provided evidence for the presence of lactobacilli in milk sources. Thus, the present study aimed to isolate and characterize different lactobacilli strains from milk sources and analyze their “probiotic potential”. Materials and methods: Forty-one lactobacilli isolates were obtained from raw cow milk. Then, the strains were characterized by morphological identification and biochemical tests. Besides, probiotic potentials were evaluated with the bile tolerance test, antibiotic susceptibility test, and determining suitable pH for the optimal growth of lactobacilli. The lactobacilli isolates were also analyzed for their probiotic characteristics and the release of antimicrobial substances. Their antimicrobial activities against pathogenic strains were assessed by determining the minimum inhibitory concentration, with the help of agar diffusion methods. Results: From 50 milk samples, 41 lactobacilli isolates were obtained, out of which five lactobacilli strains were identified as Lactobacillus casei, Lactobacillus plantarum, Lactobacillus brevis, Lactobacillus acidophilus, and Lactobacillus lactis. Moreover, 35 isolates showed an inhibitory effect. These strains were able to survive and grow in 0.5% to 2.5% bile salt concentrations. Lactic acid bacteria were susceptible to antibiotics, and 35 isolates obtained from raw milk showed an inhibitory effect against pathogenic bacteria. The observed minimum inhibitory concentration ranged from 50 to 100 µL and varied between the different pathogens. Conclusion: Out of 41 Lactobacillus isolates obtained from cow milk samples, 35 were identified with probiotic characteristics. Hence, this study highlighted the novel probiotic bacteria and validated the antimicrobial properties of the Lactobacillus spp against pathogenic bacteria.
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Bobcek, B., Ľ. Gajdosová, M. Kacániová, J. Lejková, L. Hleba et V. Kmeť. « Antibacterial susceptibility of lactobacilli isolated from pork meat of conventional breeding ». Biotehnologija u stocarstvu 27, no 3 (2011) : 799–807. http://dx.doi.org/10.2298/bah1103799b.
Texte intégralRésumé :
The aim of this study was monitoring of antibiotic resistance of Enterobacteriaceae genera isolated from musculus longissimus at thoracis and musculus semimembranosus of pork. The pigs was feeding in two groups (control and experimental wit selenium application). For the antibiotic susceptibility testing disk diffusion method was used. Lactobacillus species were tested against two antibiotics: ampiciline, tetracycline. For the detection and identification of lactobacilli we used MRS and Rogose agar. For identification of lactobacilli MALDI-TOF-MS were used. The higher resistance of isolated bacteria were found on ampicillin (29%) and on tetracycline (46%) in experimental group. The lower resistance of isolated bacteria were found on ampicillin (25%) and on tetracycline (35%) in control group. The most resistance bacteria of Lactobacillus genus was Lactobacillus plantarum in control and experimental group, too. From MLT and MSM pork meat Lactobacillus species Lactobacillus reuteri, L. crispatus, L.paracasei, L. farcimins and L curvatus and from non-lactobacilli Lactococcus lastis, Pediococcus pentosaceus were isolated (Table 2). The higher isolated species from lactobacilli genera was Lactobacillus paracasei in control group with 35.63 % and Lactobacillus reuteri in experimental group with 25.83%.
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MURAD, H. A., R. I. REFAEA et E. M. ALY. « Utilization of UF-Permeate for Production of β-galactosidase by Lactic Acid Bacteria ». Polish Journal of Microbiology 60, no 2 (2011) : 139–44. http://dx.doi.org/10.33073/pjm-2011-019.
Texte intégralRésumé :
Four lactobacilli strains (Lactobacillus bulgaricus, Lactobacillus acidophilus, Lactobacilus casei and Lactobacillus reuteri) were grown in MRS broth and three lactococci strains (Streptococcus thermophilus, Lactococcus lactis subsp. Lactis and Lactococcus lactis subsp. lactis biovar. diacetilactis) were grown in M17 broth. L. reuteri and S. thermophilus were chosen on the basis of the best mean beta-galactosidase activity of 10.44 and 10.01 U/ml respectively, for further studies on permeate-based medium. The maximum production of beta-galactosidase by L. reuteri was achieved at lactose concentration of 6%, initial pH 5.0-7.5, ammonium phosphate as nitrogen source at a concentration of 0.66 g N/L and incubation temperature at 30 degrees C/24 hrs to give 6.31 U/ml. While in case of S. thermophilus, maximum beta-galactosidase production was achieved at 10% lactose concentration of permeate medium, supplemented with phosphate buffer ratio of 0.5:0.5 (KH2PO4:K2HPO4, g/L), at initial pH 6.0-6.5, ammonium phosphate (0.66g N/L) as nitrogen source and incubation temperature 35 degrees C for 24 hrs to give 7.85 U/ml.
7
Stojanov, Spase, Tina Vida Plavec, Julijana Kristl, Špela Zupančič et Aleš Berlec. « Engineering of Vaginal Lactobacilli to Express Fluorescent Proteins Enables the Analysis of Their Mixture in Nanofibers ». International Journal of Molecular Sciences 22, no 24 (20 décembre 2021) : 13631. http://dx.doi.org/10.3390/ijms222413631.
Texte intégralRésumé :
Lactobacilli are a promising natural tool against vaginal dysbiosis and infections. However, new local delivery systems and additional knowledge about their distribution and mechanism of action would contribute to the development of effective medicine. This will be facilitated by the introduction of the techniques for effective, inexpensive, and real-time tracking of these probiotics following their release. Here, we engineered three model vaginal lactobacilli (Lactobacillus crispatus ATCC 33820, Lactobacillus gasseri ATCC 33323, and Lactobacillus jensenii ATCC 25258) and a control Lactobacillus plantarum ATCC 8014 to express fluorescent proteins with different spectral properties, including infrared fluorescent protein (IRFP), green fluorescent protein (GFP), red fluorescent protein (mCherry), and blue fluorescent protein (mTagBFP2). The expression of these fluorescent proteins differed between the Lactobacillus species and enabled quantification and discrimination between lactobacilli, with the longer wavelength fluorescent proteins showing superior resolving power. Each Lactobacillus strain was labeled with an individual fluorescent protein and incorporated into poly (ethylene oxide) nanofibers using electrospinning, as confirmed by fluorescence and scanning electron microscopy. The lactobacilli retained their fluorescence in nanofibers, as well as after nanofiber dissolution. To summarize, vaginal lactobacilli were incorporated into electrospun nanofibers to provide a potential solid vaginal delivery system, and the fluorescent proteins were introduced to distinguish between them and allow their tracking in the future probiotic-delivery studies.
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Dong, Jie, Yun Sheng Jiang, Hai Yu, Wen Juan Zhang et Yu Feng Liu. « Study on Lactobacillus Isolation from Rabbit Meat Sausage and its Fermentation Property ». Applied Mechanics and Materials 140 (novembre 2011) : 431–40. http://dx.doi.org/10.4028/www.scientific.net/amm.140.431.
Texte intégralRésumé :
Three lactobacilli (L26, L34 , L106) isolated from naturally fermented rabbit sausage in a traditional way are identified as lactobacillus plantarum, lactobacillus sake and lactobacillus fructosus. Further study of its fermentation property shows that three lactobacilli are effective in acid production, alkali resistant, nitrite resistant and bacteriostatic, and are antagonisticaction free, which can be used as combined rabbit meat starter.
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Výrostková, Jana, Ivana Regecová, Mariana Kováčová, Slavomír Marcinčák, Eva Dudriková et Jana Maľová. « Antimicrobial Resistance of Lactobacillus johnsonii and Lactobacillus zeae in Raw Milk ». Processes 8, no 12 (10 décembre 2020) : 1627. http://dx.doi.org/10.3390/pr8121627.
Texte intégralRésumé :
Lactobacillus johnsonii and Lactobacillus zeae are among the lactobacilli with probiotic properties, which occur in sour milk products, cheeses, and to a lesser extent in raw milk. Recently, resistant strains have been detected in various species of lactobacilli. The aim of the study was to determine the incidence of resistant Lactobacillus johnsonii and Lactobacillus zeae strains in various types of raw milk. A total of 245 isolates were identified by matrix-assisted laser desorption/ionization mass spectrometry and polymerase chain reaction methods as Lactobacillus sp., of which 23 isolates of Lactobacillus johnsonii and 18 isolates of Lactobacillus zeae were confirmed. Determination of susceptibility to selected antibiotics was performed using the E-test and broth dilution method, where 7.3% of lactobacilli strains were evaluated as ampicillin-resistant, 14.7% of isolates as erythromycin-resistant, and 4.9% of isolates as clindamycin-resistant. The genus Lactobacillus johnsonii had the highest resistance to erythromycin (34.8%), similar to Lactobacillus zeae (33.3%). Of the 41 isolates, the presence of the gene was confirmed in five Lactobacillus johnsonii strains and in two strains of Lactobacillus zeae. The presence of resistant strains of Lactobacillus johnsonii and Lactobacillus zeae is a potential risk in terms of spreading antimicrobial resistance through the food chain.
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CHANG, M. H., et T. C. CHEN. « Reduction of Campylobacter jejuni in a Simulated Chicken Digestive Tract by Lactobacilli Cultures ». Journal of Food Protection 63, no 11 (1 novembre 2000) : 1594–97. http://dx.doi.org/10.4315/0362-028x-63.11.1594.
Texte intégralRésumé :
Studies were conducted to investigate the impact of a selected lactobacilli mixed culture on Campylobacter jejuni in simulated chicken digestive tract models. Veronal buffer solutions corresponding to the pH of successive segments of the chicken digestive tract were prepared. The lactobacilli mixtures were prepared by mixing four fresh lactobacilli cultures, including Lactobacillus acidophilus, Lactobacillus fermentum, Lactobacillus crispatus, and Lactobacillus brevis. The C. jejuni and lactobacilli mixture were mixed with sterile poultry feed, and the previously prepared veronal buffer solutions were then added separately. The mixture was incubated at 41.1°C for various lengths of time with periodic agitation. The feed passage time for five segments of the digestive tract were adopted: crop (pH 4.5), 30 min; proventriculus (pH 4.4), 15 min; gizzard (pH 2.6), 90 min; small intestine (pH 6.2), 90 min; and large intestine (pH 6.3), 15 min. The Campylobacter and lactobacilli were enumerated. An antagonistic effect on C. jejuni by the tested lactobacilli spp. was found in individual sections and the complete simulated digestive tract models. In the simulated complete chicken digestion system, no C. jejuni were found during the final incubation period when a lactobacilli mixture was present. The results of this in vitro study indicate the potential value of future in vivo studies.
Thèses sur le sujet "Lactobacillu"
1
LONGO, STEFANO. « Lactobacillus crispatus M247 : azioni immuno - modulanti e interazioni molecolari con l' epitelio intestinale ». Doctoral thesis, Università Cattolica del Sacro Cuore, 2009. http://hdl.handle.net/10280/405.
Texte intégralRésumé :
Con il primo lavoro è stato identificato un tratto fenotipico di un ceppo di L.crispatus associato alla capacità di persistere e colonizzare il colon dell’ospite e di modificarene la composizione microbica, tale L.crispatus M247 è in grado di modificare, nell’epitelio del colon, il livello di espressione dei TLR2 dei TLR4 sia in vitro che in vivo. Con il secondo studio si identifica un meccanismo antinfiammatorio, prima sconosciuto, indotto da un ceppo probiotico che coinvolge l’attivazione di PPAR-γ e fornisce una nuova visuale sui meccanismi molecolari coinvolti nel dialogo tra epitelio intestinale e microbiota simbionte.The colonic microbiota is a major modulator of the mucosal immune system; therefore, its manipulation through supplementation with probiotics may significantly affect the host’s immune responses. Since different probiotics seem to exert various effects in vivo, we tested the relevance of the autoaggregation phenotype on the intestinal persistence of lactobacilli and their ability to modulate the host’s innate immune responses. After 14 days of diet supplementation, the aggregating strain Lactobacillus crispatus M247 but not aggregation-deficient isogenic mutant MU5 was recovered from the feces and colonic mucosa of mice. This observation was confirmed by strain-specific PCR amplification and by Lactobacillus-specific denaturing gradient gel electrophoresis analysis. Indeed, L. crispatus M247 increased Toll-like receptor 2 (TLR2) mRNA levels, while it reduced TLR4 mRNA and protein levels in the colonic mucosa, whereas MU5 was ineffective. In colonic epithelial cells (CMT-93 cells) L. crispatus M247 but not MU5 induced time-dependent extracellular signal-regulated kinase-1 (ERK1) tyrosine phosphorylation and TLR modulation, which were abolished in the presence of PD98059 (an ERK1 inhibitor). To assess the functional relevance of probiotic-induced TLR modulation, we determined the consequences of L. crispatus preexposure on TLR4 (lipopolysaccharide [LPS]) and TLR2 [Pam3Cys-Ser-(Lys)4] ligand-mediated effects in intestinal epithelial cells. Preexposure to L. crispatus M247 blunted LPS-induced interleukin-6 (IL-6) release and inhibition of CMT-93 migration over a wound edge, whereas it enhanced TLR2-mediated IL-10 up-regulation. In summary, the aggregation phenotype is required for L. crispatus persistence in the colon and for modulation of TLR2/TLR4 expression through an ERK-dependent pathway. We speculate that the aggregation phenotype in L. crispatus M247 is required to temper epithelial cell responsiveness to bacterial endotoxins, which thus affects the evolution of intestinal inflammatory processes. Accumulating evidence indicates that the peroxisome proliferator activated receptor (PPAR)- is a major player in maintaining intestinal mucosa homeostasis, but whether PPAR- is directly involved in probiotic-mediated effects and the molecular events involved in its activation are not known. Methods: We investigated the role of PPAR- in the immunomodulatory effects of Lactobacillus crispatus M247 on intestinal epithelial cells (IEC) and the role of probiotic-derived H2O2 on PPAR- activity. Results: L crispatus M247 supplementation in mice significantly increased PPAR- levels and transcriptional activity in the colonic mucosa. L crispatus M247 induced PPAR- nuclear translocation and enhanced transcriptional activity in epithelial (CMT-93) cells, as demonstrated by the increased luciferase activity of a PPAR- –responsive element, PPAR- – responsive gene up-regulation, and reduced activity of an nuclear factor- B–responsive element. Pharmacologic PPAR- inhibition or silencing by small interfering RNA cancelled the L crispatus M247–mediated effects in CMT-93 cells. Because Lactobacillus strains producing little H2O2 failed to activate PPAR- , we investigated the role of L crispatus M247– derived H2O2 in PPAR- activation. L crispatus M247 induced a transient rise in intracellular H2O2 and PPAR- transcriptional activity was cancelled by antioxidant or H2O2 scavenger. Toll-like receptor (TLR)-2 was not required for PPAR- up-regulation mediated by L crispatus M247 in mice, although the protective effects of L crispatus M247 on dextran sodium sulfate-induced colitis were less pronounced in TLR-2 / mice. Conclusions: L crispatus M247 uses H2O2 as a signal transducing molecule to induce PPAR- activation in IEC, directly modulating epithelial cell responsiveness to inflammatory stimuli.
2
LONGO, STEFANO. « Lactobacillus crispatus M247 : azioni immuno - modulanti e interazioni molecolari con l' epitelio intestinale ». Doctoral thesis, Università Cattolica del Sacro Cuore, 2009. http://hdl.handle.net/10280/405.
Texte intégralRésumé :
Con il primo lavoro è stato identificato un tratto fenotipico di un ceppo di L.crispatus associato alla capacità di persistere e colonizzare il colon dell’ospite e di modificarene la composizione microbica, tale L.crispatus M247 è in grado di modificare, nell’epitelio del colon, il livello di espressione dei TLR2 dei TLR4 sia in vitro che in vivo. Con il secondo studio si identifica un meccanismo antinfiammatorio, prima sconosciuto, indotto da un ceppo probiotico che coinvolge l’attivazione di PPAR-γ e fornisce una nuova visuale sui meccanismi molecolari coinvolti nel dialogo tra epitelio intestinale e microbiota simbionte.The colonic microbiota is a major modulator of the mucosal immune system; therefore, its manipulation through supplementation with probiotics may significantly affect the host’s immune responses. Since different probiotics seem to exert various effects in vivo, we tested the relevance of the autoaggregation phenotype on the intestinal persistence of lactobacilli and their ability to modulate the host’s innate immune responses. After 14 days of diet supplementation, the aggregating strain Lactobacillus crispatus M247 but not aggregation-deficient isogenic mutant MU5 was recovered from the feces and colonic mucosa of mice. This observation was confirmed by strain-specific PCR amplification and by Lactobacillus-specific denaturing gradient gel electrophoresis analysis. Indeed, L. crispatus M247 increased Toll-like receptor 2 (TLR2) mRNA levels, while it reduced TLR4 mRNA and protein levels in the colonic mucosa, whereas MU5 was ineffective. In colonic epithelial cells (CMT-93 cells) L. crispatus M247 but not MU5 induced time-dependent extracellular signal-regulated kinase-1 (ERK1) tyrosine phosphorylation and TLR modulation, which were abolished in the presence of PD98059 (an ERK1 inhibitor). To assess the functional relevance of probiotic-induced TLR modulation, we determined the consequences of L. crispatus preexposure on TLR4 (lipopolysaccharide [LPS]) and TLR2 [Pam3Cys-Ser-(Lys)4] ligand-mediated effects in intestinal epithelial cells. Preexposure to L. crispatus M247 blunted LPS-induced interleukin-6 (IL-6) release and inhibition of CMT-93 migration over a wound edge, whereas it enhanced TLR2-mediated IL-10 up-regulation. In summary, the aggregation phenotype is required for L. crispatus persistence in the colon and for modulation of TLR2/TLR4 expression through an ERK-dependent pathway. We speculate that the aggregation phenotype in L. crispatus M247 is required to temper epithelial cell responsiveness to bacterial endotoxins, which thus affects the evolution of intestinal inflammatory processes. Accumulating evidence indicates that the peroxisome proliferator activated receptor (PPAR)- is a major player in maintaining intestinal mucosa homeostasis, but whether PPAR- is directly involved in probiotic-mediated effects and the molecular events involved in its activation are not known. Methods: We investigated the role of PPAR- in the immunomodulatory effects of Lactobacillus crispatus M247 on intestinal epithelial cells (IEC) and the role of probiotic-derived H2O2 on PPAR- activity. Results: L crispatus M247 supplementation in mice significantly increased PPAR- levels and transcriptional activity in the colonic mucosa. L crispatus M247 induced PPAR- nuclear translocation and enhanced transcriptional activity in epithelial (CMT-93) cells, as demonstrated by the increased luciferase activity of a PPAR- –responsive element, PPAR- – responsive gene up-regulation, and reduced activity of an nuclear factor- B–responsive element. Pharmacologic PPAR- inhibition or silencing by small interfering RNA cancelled the L crispatus M247–mediated effects in CMT-93 cells. Because Lactobacillus strains producing little H2O2 failed to activate PPAR- , we investigated the role of L crispatus M247– derived H2O2 in PPAR- activation. L crispatus M247 induced a transient rise in intracellular H2O2 and PPAR- transcriptional activity was cancelled by antioxidant or H2O2 scavenger. Toll-like receptor (TLR)-2 was not required for PPAR- up-regulation mediated by L crispatus M247 in mice, although the protective effects of L crispatus M247 on dextran sodium sulfate-induced colitis were less pronounced in TLR-2 / mice. Conclusions: L crispatus M247 uses H2O2 as a signal transducing molecule to induce PPAR- activation in IEC, directly modulating epithelial cell responsiveness to inflammatory stimuli.
3
Allain, Thibault. « Rôle des Bile Salt Hydrolases (BSH) des lactobacilles probiotiques dans le contrôle de la giardiose ». Thesis, Paris, AgroParisTech, 2016. http://www.theses.fr/2016AGPT0018.
Texte intégralRésumé :
Giardia duodenalis est le protozoaire responsable de la giardiose, la parasitose intestinale la plus répandue dans le monde. Cette infection se caractérise par une malabsorption intestinale, des diarrhées, une perte de poids et des douleurs abdominales intenses chez l’Homme et de nombreux mammifères. Par ailleurs, cette maladie dont l’impact en santé publique et vétérinaire est reconnu, peut entraîner d’importantes déficiences nutritionnelles en particulier chez les sujets jeunes. L’infection est causée par l’ingestion de kystes de Giardia duodenalis (syn. G. lamblia, G. intestinalis) présents dans les aliments ou l’eau contaminée. Infectieux à très faibles doses, ces kystes survivent pendant plusieurs semaines dans l’environnement et sont résistants aux différents désinfectants. Suite au dékystement, la forme végétative de Giardia, le trophozoïte, adhère à l’épithélium intestinal au niveau des parties supérieures de l’intestin grêle et se multiplie, causant les symptômes. Cette phase se termine par un nouvel enkystement et l’excrétion de kystes par les fèces. Le nombre croissant d’infections liées à la contamination de l’eau potable, à l’émergence de souches résistantes aux médicaments disponibles, à la fréquence des échecs thérapeutiques et à l’importance des effets secondaires associés aux traitements font de cette maladie un sujet d’actualité de plus en plus préoccupant qui nécessite le développement de traitements alternatifs. Il est désormais bien établi que le microbiote et/ou certaines souches de bactéries probiotiques ont un impact bénéfique dans la giardiose. En particulier, la bactérie probiotique Lactobacillus johnsonii La1 (LjLa1) a un rôle protecteur contre la croissance de Giardia in vitro et in vivo. Nous avons cherché dans ce travail de Thèse à décrypter les mécanismes moléculaires associés à l’effet inhibiteur des facteurs sécrétés par LjLa1. Nous avons montré qu’in vitro, LjLa1 agissait en libérant des enzymes de type Bile Salt Hydrolases (BSH) qui modifient alors des composants de la bile non-toxiques pour le parasite (sels biliaires conjugués) en des composants toxiques (sels biliaires déconjugués). Les 3 gènes BSH codés dans le génome de LjLa1 ont été clonés chez Escherichia coli et les protéines taguées histidine purifiées pour étudier leurs propriétés biochimiques et biologiques. Obtenues sous forme active, nous avons pu en définir les spécificités de substrats et montrer qu’elles sont capables d’inhiber significativement la croissance de G. duodenalis in vitro et in vivo, dans un modèle murin de la giardiose (souriceaux OF1 non sevrés). En parallèle, nous avons identifié, à l’issue d’un large criblage de souches de lactobacilles selon leur activité anti-Giardia in vitro, une souche probiotique aux effets inhibiteurs comparables à ceux de LjLa1 : Lactobacillus gasseri CNCM-4884. Administrée in vivo dans le modèle murin de la giardiose, cette souche a réduit de 93% la charge parasitaire dans l'intestin grêle des nouveaux nés et a également réduit de façon significative le nombre de kystes libérés dans l’environnement, permettant ainsi de réduire la transmission de Giardia. Des travaux parallèles ont été réalisés au cours de ce projet de Thèse, notamment le développement d’outils de moléculaire pour l’expression hétérologue de molécules d’intérêt en santé animale chez divers lactobacilles. Le développement de ces « vecteurs mucosaux » permettra à terme de proposer une stratégie de surexpression de BSH par les lactobacilles afin d’accroitre l’activité BSH in vivo, et renforcer ainsi l’élimination du parasite. Ces résultats permettent de proposer de nouvelles pistes thérapeutiques originales contre les giardioses humaines et animales, basées sur l’utilisation de lactobacilles probiotiques ou sur les activités BSH qui en sont dérivées. Ces traitements offrent alors une alternative sérieuse aux antibiotiques et permettront de pallier aux actuels fréquents échecs thérapeutiquesGiardia duodenalis is a protozoan parasite responsible for giardiasis, the most common intestinal parasitic disease worldwide. This infection is characterized by intestinal malabsorption, diarrhea, weight loss and abdominal pain in humans and various mammalian species. Besides, this disease has a high veterinary and public health impact, leading to important nutritional deficiencies in young subjects. The infection is caused by the ingestion of food or water contaminated with infectious cysts of the parasite. Giardia cysts can survive for several weeks in the environment and are highly resistant to disinfectants. Giardia excysts in the intestinal tracts of its host and replicates under the trophozoite stage causing the symptoms. Trophozoites adhere to the intestinal epithelium of the small intestine and multiply, causing the symptoms. The cycle ends by a new encystment and infectious cysts are released in environments with feces. The increasing number of giardiasis cases, mainly due to water contaminations, the emergence of parasite strains resistant to drugs and therapeutic failures, make research on alternative therapeutic strategies and treatments highly needed. Nowadays, it is well known that the microbiota and probiotics play an important role in protection against this parasite. For instance, the probiotic strain Lactobacillus johnsonii La1 (LjLa1) prevents the establishment of Giardia in vitro and in vivo. In this thesis, we have tried to point out the molecular mechanism(s) involved in this inhibitory effect(s). We showed in vitro that LjLa1 was releasing "Bile Salt Hydrolases" (BSH) – like activities that modify some components of bile (conjugated bile salts) into toxic compounds (deconjugated bile salts) for Giardia. We have cloned and expressed each of the three bsh genes present in the genome of LjLa1 in Escherichia coli in order to study their enzymatic and biological properties. Two BSH were obtained as recombinant active enzymes and biochemical tests showed that they have distinct substrate specificities despite similar predicted 3D structures. Moreover, these two BSHs of LjLa1 exhibited anti-giardial effects in vitro and in vivo in a murine model of the giardiasis (OF1suckling mice), comforting the hypothesis of the biological role of active BSH, derived from probiotics, against Giardia. A wide collection of diverse lactobacilli strains was screened to assess their effectiveness to also display both anti-giardial and BSH activities. This screening allowed the identification of several strains exhibiting strong anti-giardial effects such as Lactobacillus gasseri CNCM I-4884. In a murine model of giardiasis, this strain dramatically reduced the parasite burden in the small intestine of treated animals and significantly reduced the number of cysts in the colon, which could contribute to blockage of parasite transmission in environments. Additional studies were realized in parallel in order to explore the potency of lactobacilli to exert beneficial effects on health. For this, molecular tools were successfully developed in various lactobacilli strains to express and deliver therapeutic molecules at mucosal surfaces. The development of these tools will further allow the overexpression of BSH by lactobacilli to increase their in vivo BSH-activity and strengthen the elimination of the parasite. Altogether, this thesis work proposes new original therapeutic strategies against human and animal giardiasis, based on the use of BSH-positive lactobacilli strains or recombinant BSH- derived from probiotic strains, to counteract the frequent therapeutic failures, offering a serious alternative to antibiotics
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Lönnermark, Elisabet. « Lactobacilli in the normal microbiota and probiotic effects of Lactobacillus plantarum / ». Göteborg : Department of Infectious Medicine, Sahlgrenska Academy, University of Gothenburg, 2010. http://hdl.handle.net/2077/21480.
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Jin, Su. « Physiological characteristics and applications of Lactobacillus pentosus strains in selected dairy products ». AgroParisTech, 2010. http://pastel.archives-ouvertes.fr/docs/00/55/22/70/PDF/These_Su_JIN.pdf.
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Deux souches de Lactobacillus pentosus, Ind1 et Ind3, ont été isolées à partir de « Naigeda », un fromage traditionnel Chinois produit dans la région du Xinjiang. Les propriétés probiotiques de L. Pentosus étant peu connues, la présente étude a été conduite afin de déterminer si ces 2 souches, Ind1 et Ind3, sont susceptibles d’être utilisées comme probiotiques. Les propriétés physiologiques de L. Pentosus Ind1 et Ind3 ont fait l’objet d’essais in vitro afin de déterminer leur tolérance à l’environnement gastro-intestinal et leur adhérence à l’épithélium intestinal. Leurs propriétés de dégradation de 3 substances carcinogènes (phénol, p-crésol et indole ; concentrations comprises entre 50 et 150 µg/mL) ainsi que leur inhibition éventuelle par ces mêmes substances ont été étudiées. Les effets des 2 souches de L. Pentosus sur la microflore intestinale de souris, après administration orale de 109cfu/mL dans 0. 5mL de lait écrémé, ont été analysés. A cet effet, les populations de Lactobacilles, Bifidobactéries, Entérobacilles, Entérocoques et Clostridium perfringens, contenues dans les fèces des souris, avant, pendant et après leur alimentation en probiotiques, ont été considérées. Enfin, les capacités des 2 souches de L. Pentosus à produire de l’acide -amino butyrique ont été étudiées, et les conditions de milieu et de culture assurant la meilleure production définies. Les résultats montrent que les 2 souches de L. Pentosus, Ind1 et Ind3, présentent des taux de survie élevés : plus de 90 % en milieu acide et de 80% dans une solution de bile. Les aptitudes à l’adhérence sont souches dépendantes, avec pour Ind3 un potentiel similaire à celui de souches probiotiques reconnues (NCFM et Lp115). Ind1 et Ind3 ont également montré une bonne résistance aux substances carcinogènes (phénol, p-crésol, indole à 150 μg/mL). Enfin, ces 2 souches permettent un accroissement des concentrations de Lactobacilles et de bifidobactéries, dans le tractus intestinal des souris, tout en inhibant la croissance des Entérobacilles et de C. Perfringens. Ces résultats démontrent les aptitudes potentielles des deux souches de L. Pentosus étudiées pour une utilisation comme souches probiotiques au sein de régimes diététiques ou pour l’élaboration de produits laitiers fermentésTwo Lactobacillus pentosus strains, Ind1 and Ind3, were isolated from a traditional Chinese cheese product called Naigeda, collected from Xinjiang region of China. Since there is little information regarding the probiotic properties of L. Pentosus strains, this study was designed to provide more supporting data for L. Pentosus as a potential probiotic strain application. The physiological properties of the two L. Pentosus strains, Ind1 and Ind3, such as the in vitro test on the intolerance under the gastro-intestinal environment, the ability of adherence on the intestinal epithelium were studied. Their intolerance as well as inhibition and degradation ability under presence of pre-carcinogenic substances existing in human gut such as phenol, p-cresol and indole at different concentrations were also determined. The effects of the two L. Pentosus strains on modulation of the mice intestinal micro flora, by oral administration of 109cfu/ml of strains in 0. 5ml of skim milk, were investigated: the amounts of Lactobacillus spp. , Bifidobacterium spp. , Enterobacilli, Enterococcus and Clostridium perfringens in the feces of mice during and after the feeding of probiotic strains were counted. Furthermore, the technological properties of the two L. Pentosus strains on their GABA producing ability were studied: the medium and process parameters optimization was carried out in order to try to obtain the highest GABA content in the fermented dairy products. Results showed that the two L. Pentosus strains had high survival rates (higher than 90% in acid and 80% in bile solution). The adhesive ability is strain independent: Ind3 adherence was comparable with those of two commercial probiotic strains (NCFM and Lp115). Ind1 and Ind3 showed good resistance mutagenic substances phenol, p-cresol, indole at concentration below 150 μg/mL). Ind1 and Ind3 also showed certain effect on promoting the increase of Lactobacillus and Bifidobacteria counts, and inhibiting the growth of Enterobacilli and Clostridium in mice gut. These results displayed positive properties that the two L. Pentosus strains can be good candidates to be used as probiotic strains potentially used in dietary supplement application or Chinese-style dairy products
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Chaves, Maria Manoela Barata de Castro [UNESP]. « Estudo da microbiota vaginal de éguas com ênfase na pesquisa de lactobacilos ». Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/98256.
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chaves_mmbc_me_botfmvz.pdf: 1213419 bytes, checksum: c6618d188eefb02feaf360154f766257 (MD5)Universidade Estadual Paulista (UNESP)
Na égua o ambiente uterino saudável não apresenta microflora, diferente da vagina onde se sabe existir uma flora vaginal rica em microrganismos não patogênicos. Muitas bactérias da flora vaginal normal podem ser deslocadas para o interior do útero, podendo ser esta a causa principal de endometrites em éguas doadoras de embriões. A presença de Lactobacillus spp é considerada importante na flora vaginal de mulheres e tem sido pouco investigada em éguas. O presente trabalho tem como objetivo estudar a flora vaginal de éguas, doadoras de embriões, determinar os principais microrganismos presentes, relacionar os achados microbiológicos vaginais e uterinos, assim como determinar a prevalência de Lactobacillus. No experimento 1 foram utilizadas 77 éguas doadoras de embrião, 33 foram coletadas amostras vaginais e uterinas e 77 apenas vaginais. O experimento 2 contou com dois grupos (36 éguas e 10 mulheres) de swabs vaginais sendo um para cultivo e isolamento de Lactobacillus e outro para extração do DNA e PCR. As bactérias predominantes na vagina foram: Streptococcus zooepidemicus (42%), Escherichia coli (25%), Streptococcus alfa hemolítico (15%) Candida (6%), Enterobacter spp (3%), Bacillus spp (3%), Streptococcus beta hemolítico (3%) e Pseudomonas (3%).. Das 33 amostras coletadas do útero de éguas somente 39% (n=12) não apresentaram crescimento bacteriano ou fúngico. Tendo sido Streptococcus zooepidemicus o mais frequentemente encontrado (26%), seguido de Escherichia coli (15%), Candida spp (9%), Streptococcus alfa hemolítico (6%) e Enterobacter (3%). Os microrganismos isolados da vagina e que estavam concomitantemente presentes no útero de éguas foram: Streptococcus zooepidemicus (21%), Escherichia coli (12%), Candida spp (9%) e Streptococcus alfa hemolítico (6%). Em 83,3% houve concordância entre as amostras negativas na vagina e no útero (p <0,05). Em 73,7%...
Different from the vagina, were a rich microflora is present, the uterine environment is considered free of microorganisms. One possibility for the installation of endometritis in mares is the ascendent contamination from the vagina.The presence of Lactobacillus on vaginal flora is considered important in woman however there is few information on mares. The present experiment aimed to study the vaginal microflora of embryo donnor mares, to correlate the vaginal and uterine finds and also to determine the prevalence of Lactobacillus on vaginal envirioment. On experiment 1 a total of 77 mares were used and vaginal samples collected from 33 of these mares both vaginal and uterine samples were collected. On experiment 2 vaginal swabs from 36 mares and 10 women were collected for culture and isolation of Lactobacillus, DNA extration and PCR. The predominate bacteria isolated from the vagina were: Streptococcus zooepidemicus (42%), Escherichia coli (25%), Streptococcus alfa hemolítico (15%) Candida (6%), Enterobacter spp (3%), Bacillus spp (3%), Streptococcus beta hemolítico (3%) e Pseudomonas (3%). From 33 samples collected from the uterus only 39% (n= 12) did not show any microorganism on culture. Streptococcus zooepidemicus was the most frequent isolated microorganism (26%), followed by Escherichia coli (15%), Candida spp (9%), Streptococcus alfa hemolítico (6%) e Enterobacter (3%). When evaluated the microorganisms isolated from both vaginal and uterine samples Streptococcus zooepidemicus (21%), Escherichia coli (12%), Candida spp (9%) e Streptococcus alfa hemolytic (6%) were the most frequent isolated bacteria. The agreement between swabs taken from both uterus and vagina was 83.3% (p <0,05) for negative cultures and 73,7% for positive cultures (p <0,05). From 35 samples collected on group I Lactobacillus spp was isolated in only two (5,7%) eight (20%) samples showed positive ... (Complete abstract click electronic access below)
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Regulski, Krzysztof. « Influence of peptidoglycan metabolism on immunomodulatory properties of Lactobacillus casei ». Thesis, Paris 11, 2012. http://www.theses.fr/2012PA112313.
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Le peptidoglycane (PG) est le composant majeur de la paroi des bactéries à Gram positif. Il assure la forme et l’intégrité de la cellule bactérienne. Le PG ou des fragments dérivés sont connus pour être des inducteurs du système d’immunité innée de l’hôte, en particulier au travers des récepteurs Nod2. Au cours de ce travail, nous avons étudié l’influence du métabolisme du PG sur les propriétés immunomodulatrices de Lactobacillus casei BL23, en étudiant principalement sa capacité à moduler la réponse des cellules dendritiques humaines. Nous avons tout d’abord caractérisé les hydrolases du PG (PGHs) majeures de L. casei BL23. Une recherche in silico a révélé que L. casei possède un système de PGHs relativement complexe comprenant treize enzymes putatives avec des domaines catalytiques variés. Une analyse protéomique d’extraits de paroi de L. casei BL23 a permis de détecter la production de sept d’entre elles pendant la croissance bactérienne. Quatre d’entre elles ont été étudié plus en détails. La PGH la plus fortement exprimée, Lc-p75, a une activité de -D-glutamyl-L-lysyl-endopeptidase et est responsable de la séparation des cellules après division. De plus, Lc-p75 associée à la paroi est localisée au niveau des septa cellulaires. Il s’agit également de l’une des protéines majeures secrétée dans le surnageant de culture de L. casei BL23. Lc-p75 possède la particularité d’être une glycoprotéine. La PGH Lc-p40 possède un domaine CHAP doué d’une activité endopeptidase avec un site de clivage situé au niveau des ponts interpeptidiques du PG. Lc-p40 parait localisée au niveau de la paroi latérale des cellules de L. casei. Lc-p45 est une deuxième -D-glutamyl-L-lysyl-endopeptidase avec un rôle dans le maintien de la forme de la bactérie. Enfin nous avons caractérisé deux enzymes de prophages, Lc-Lys et Lc-Lys2, codée par le génome de L. casei BL23, qui possède toute deux un domaine de liaison au PG d’un nouveau type qui possède la particularité de lier spécifiquement le D-Asp amidé présent dans les ponts interpeptidiques du PG de L. casei BL23. La délétion des deux gènes qui codent pour les endopeptidases Lc-p75 et Lc-p45 chez L. casei BL23 conduit à l’absence de disaccharide dipeptide dans la structure du PG du mutant, tandis que la délétion de Lc-p75 seulement conduit à une réduction de la quantité du disaccharide-dipeptide. Ce disaccharide dipeptide est un ligand des récepteurs Nod2. Les deux mutants obtenus par délétion de Lc-p75 ou bien par délétion des deux endopeptidases ont été comparés avec la souche sauvage BL23 pour leur capacité à activer in vitro des cellules dendritiques humaines dérivées de monocytes sanguins. Suite à l’activation des cellules dendritiques par les souches de L. casei, quatre cytokines pro-inflammatoires, les interleukines IL-6, IL-8, IL-12 et le TNF- ont été produites. La quantité de chaque cytokine sécrétée en réponse aux mutants simple Lc-p75 et double Lc-p75/Lc-p45 était diminuée par rapport à celle induite par la souche sauvage L. casei BL23.En conclusion, L. casei BL23 est doté d’un équipement complexe en PGHs. Les PGHs caractérisées au cours de ce travail présentent des caractéristiques uniques et jouent un rôle important dans la division des bactéries ainsi que dans le maintien de leur morphologie. Nos résultats indiquent que la souche sauvage de L. casei Bl23 et les mutants dérivés obtenus par inactivation d’enzymes à activité endopeptidase, qui diffèrent à la fois au niveau de leur contenu enzymatique ainsi qu’au niveau de la structure de leur PG, ont des effets différents sur les cellules dendritiques humaines, avec un caractère anti-inflammatoire plus élevé pour les mutantsPeptidoglycan (PG) is the major component of the Gram-positive bacteria cell wall. It ensures bacterial cell shape and integrity. PG or PG-derived fragments have been shown to stimulate the host innate immune system, through Nod-2 receptors. In this work, we studied the influence of PG metabolism on immunomodulatory properties of Lactobacillus casei BL23, mainly its ability to modulate the response of human dendritic cells (DCs).We have first characterized the main peptidoglycan hydrolases (PGHs) of L. casei BL23. In silico search revealed that L. casei BL23 has a rather complex PGH complement including thirteen predicted PGHs with various catalytic domains. Proteomic analysis of bacterial cell wall extracts revealed the expression of seven of them during bacterial growth. We characterized four of them in details. Lc-p75 is the major PGH with a γ-D-glutamyl-L-lysyl-endopeptidase specificity and is responsible for daughter cell separation. Lc-p75 associated to the cell wall localizes at the cell septa. It is also one of the major secreted proteins of L. casei found in culture supernatant. Besides, we showed that L. casei Lc-p75 is a glycosylated protein. Lc-p40 is a PGH with a CHAP-domain endowed with endopeptidase hydrolytic specificity toward peptidoglycan cross-bridges and appears to localize on lateral cell wall. Lc-p45 is a second γ-D-glutamyl-L-lysyl endopeptidase with a role in cell shape maintenance. We further demonstrated that two prophage endolysins Lc-Lys and Lc-Lys2, encoded in L. casei BL23 genome, share a common novel type peptidoglycan-binding domain that recognizes specifically D-Asn cross-bridge, present in L. casei BL23 peptidoglycan.Deletion of the two endopeptidases, Lc-75 and Lc-p45, resulted in a complete loss ofdisaccharide-dipeptide, which is a ligand of Nod-2 receptor, in the muropeptide structure of L. casei BL23, whereas deletion of Lc-p75 gene led only to a reduction of disaccharide dipeptide. The two PGH-mutants, obtained by deletion of Lc-p75 gene alone or both Lc-p75 and Lc-p45 endopeptidase genes were compared with wild type L. casei BL23 for their capacity to stimulate signaling pathways in vitro in DCs derived from human monocytes. As a consequence of DC activation by L. casei strains, four pro-inflammatory cytokines IL-6, IL-8, IL-12 and TNF-α were produced. The concentrations of secreted cytokines in response to the single Lc-p75 and Lc-p75/p45 double mutant were lower than those induced by wild type L. casei BL23.In conclusion, L. casei BL23 has a complex PGH complement. The PGHs described in this work present unique features and play important role in cell division and morphology of L. casei. Our results indicate that wild type L. casei and endopeptidase-negative mutants, which differ in their PGH content and in their PG structure, have distinct effects on human DCs, with a higher anti-inflammatory character of the endopeptidase-negative mutants
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Polizzi, Andrea. « Studio sulla valorizzazione della crusca di canapa come sottoprodotto industriale, analisi della capacità prebiotica ». Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2019.
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In questo lavoro di tesi è stata studiata l’idrolisi batterica del sottoprodotto crusca della farina di semi di canapa ottenuta dalla lavorazione industriale della canapa da fibra e/o alimentare (Cannabis sativa L.), con lo scopo di valorizzarne i componenti bioattivi rilasciati, per un loro impiego nell’industria alimentare o cosmetica. In particolare, oltre alla capacità di idrolizzare e rendere maggiormente bio-accessibili le proteine vegetali della canapa, si è voluto studiarne le capacità prebiotiche sui batteri benefici del tratto gastro-intestinale umano. Dopo aver messo a punto un protocollo che comprendeva sia un trattamento termico che la diluizione ottimale della sospensione della crusca, questa è stata fermentata con differenti specie di Lactobacillus spp.: L. casei, L. rhamnosus, L. plantarum e L. fermentum. L’inoculo batterico iniziale è stato di 6 Log10 CFU/ml e l’idrolisi è stata condotta prima in una fase di screening per 24 ore e poi in una fase in tempi prolungati fino a 72 ore, utilizzando solo le combinazioni e le specie batteriche più promettenti. Le performance di crescita sono state studiate con la quantificazione del carico microbico e la valutazione del pH del mezzo. La quantificazione è stata eseguita sia con tecnica coltura-dipendente, che con coltura-indipendente, tramite qPCR. Inoltre, su differenti campioni di crusca di canapa è stato condotto il saggio di attività prebiotica, anch’esso per via molecolare, confrontandone le performances con farina di semi di canapa e con Frutto-oligosaccaridi di cicoria (FOS). I risultati hanno mostrato che il campione con l’attività prebiotica maggiore verso Lactobacillus probiotico è quella idrolizzata da un pool di tre specie di lattobacilli differenti; mentre verso Bifidobacterium probiotico è quella della crusca che ha subito solo trattamento termico. Nel primo caso, l’attività prebiotica aveva valori simili al FOS, che ad oggi è l'unico composto con l'indicazione prebiotica accettata dall'EFSA
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Harris, Lyle Keenan. « Comparison of plasmids from clinical Lactobacillus strains ». University of the Western Cape, 2018. http://hdl.handle.net/11394/6439.
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Magister Scientiae - MSc (Biotechnology)The vaginal mucosa is dominated by Gram positive, rod shaped lactobacilli which serve as a natural barrier against infection. In both healthy and BV infected women Lactobacillus crispatus and Lactobacillus jensennii has been found to be the predominant Lactobacillus species. Many studies have been conducted to assess factors influencing lactobacilli dominance in the vaginal microbiome. However, no study has evaluated the impact of plasmids on the vaginal lactobacilli. In the present study two plasmids, pLc17 and pLc4, isolated from vaginal Lactobacillus species of both healthy and BV infected women were characterized. pLc4 was present in both Lactobacillus crispatus and Lactobacillus jensennii while pLc17 was only present in Lactobacillus crispatus. pLc17 (16663 bp in size) encoded a ribonucleotide diphosphate reductase (RNR), a filamentation induced by cAMP-like (FIC-like) protein and numerous mobile elements.
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Storelli, Gilles. « Caractérisation de l’interaction mutualiste liant Drosophila melanogaster à son symbionte Lactobacillus plantarum ». Thesis, Lyon, École normale supérieure, 2015. http://www.theses.fr/2015ENSL1041.
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Le microbiote a un impact majeur sur la physiologie de son hôte, cependant notre compréhension des mécanismes régulant la relation hôte/microbiote reste limitée. Nous utilisons un hôte modèle simple, la Drosophile, afin de répondre à ces questions. Durant mon doctorat, je me suis attaché à une étape particulière du cycle de vie de la Drosophile, sa phase larvaire. Celle-ci constitue sa phase de croissance et est influencée par le contexte nutritionnel. Le microbiote influence également cette étape: l’association avec la bactérie Lactobacillus plantarum tempère les effets de la carence alimentaire en soutenant un taux de croissance élevé et une maturation rapide, en modulant chez l’hôte l’activité de l’hormone Ecdysone et de l’insuline. En retour, L.plantarum bénéficie de l’association, les larvesassurant sa persistance dans la niche (la niche étant le substrat nutritif, les larves et les bactéries associées). Pour caractériser les mécanismes mis en jeu dans ce mutualisme nous avons décrit les réponses transcriptomiques et métaboliques de la larve et avons également étudié les perturbations métaboliques de la niche. Nos résultats mettent en avant l’optimisation de l’extraction des acides aminés du substrat comme facteur clef du mutualisme. L.plantarum active l’expression des protéases intestinales de l’hôte via la voie IMD/NF-κB, et bénéficierait en retour d’une quantité d’acides aminés plus importante assurant sa persistance. Ainsi, nos travaux contribuent à l’effort de compréhension desmécanismes régulant l’interaction hôte/microbiote et pourraient conduire à de nombreuses applications thérapeutiques, notamment dans le cadre de déséquilibres nutritionnelsSymbiotic bacterial populations (also called the “microbiota”) have a dramatic impact on their host’s physiology. However, our understanding of the mechanisms shaping host/microbes mutualism remains limited. We took advantage of Drosophila tractability to characterize the host’s and the microbial factors engaged in mutualism. During my PhD, I focused on the impact of the microbiota during the Drosophila larval phase, which constitutes its juvenile growth period. Drosophila larval phase is influenced by nutrition, but also by symbiotic microbes: specific association with the bacterium Lactobacillus plantarum buffers the deleterious effects of nutrient scarcity on the host’s juvenile growth, by sustaining greater growth rates and hastening maturation. L.plantarum mediate these effects by modulating the activity of the steroid hormone Ecdysone and the Insulin/Insulin-like Signaling pathway in its host. In return, L.plantarum benefits from Drosophila presence, as larvae ensure its long-term persistence in the niche (the niche being the nutritive substrate, the larvae and the bacteria dwelling on it). To characterize the mechanisms engaged in this mutualistic relationship, we described the host’s transcriptomic and metabolic responses to L.plantarum presence and characterized the metabolic perturbations occurring in the niche. Our results put forward the optimization of amino-acids extraction from the nutritive substrate as a cornerstone of mutualism. L.plantarum activates the expression of the host’s digestive proteases via IMD/NF-κB signaling and would benefit in return from an enhanced AA availability, which would help sustaining its long-term persistence. Altogether, our studies contribute to the understanding of the mechanisms regulating host/microbiota interaction and could lead to numerous therapeutic applications, notably aiming at counteracting the deleterious effects of nutritional imbalances
Livres sur le sujet "Lactobacillu"
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Campos, Alba I. Perez, et Arturo Leon Mena. Lactobacillus : Classification, uses and health implications. Hauppauge, N.Y : Nova Science Publisher's, 2012.
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Åsa, Ljungh, et Wadström Torkel, dir. Lactobacillus molecular biology : From genomics to probiotics. Norfolk, UK : Caister Academic, 2009.
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Heath, Catherine M. The enzymology of N-deoxyribosyltransferase from Lactobacillus leichmannii. [s.l.] : typescript, 1991.
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Wall, Torun. Environmental interactions of Lactobacillus reuteri : Signal transduction, gene expression and extracellular proteins of a lactic acid bacterium. Uppsala : Swedish University of Agricultural Sciences, 2005.
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Ru suan jun yu fang ai zheng. Taibei Shi : Lin yu wen hua shi ye you xian gong si, 2001.
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G, Hoover Dallas, et Steenson Larry R, dir. Bacteriocins of lactic acid bacteria. San Diego : Academic Press, 1993.
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Sidorenko, Oleg. Microbiological bases of natural milk starter culture. ru : INFRA-M Academic Publishing LLC., 2021. http://dx.doi.org/10.12737/1150302.
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For the first time, the educational and methodological manual summarizes knowledge about the peculiarities of the ecology of lactobacilli of natural starter cultures of different geographical zones of Russia. Geographical races of lactobacilli and yeast of dairy national products can be a source of new, more resistant to extreme factors (including medicinal preparations) enzymes that will be in demand in biotechnology, medicine.
Gives fundamentally important predictions that can be experimentally verified. The prospect of treating the microbiome of the digestive organs is shown — eliminating therapy with bacteriophages, lactotherapy instead of chemotherapy.
Meets the requirements of the federal state educational standards of higher education of the latest generation.
It is intended for the preparation of students of biological specialties, agricultural technologists, as well as bachelors in the profiles "Technology of production, storage and processing of animal products" and "Natural starter cultures" in the directions: 35.03.07 "Technology of production and processing of agricultural products", 19.03.03 and 19.04.03 "Food of animal origin".
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Sidorenko, Oleg, Ekaterina Zhukova, Aleksey Ivanov et Lyudmila Kostyuchenko. Sitology and lactotherapy. ru : INFRA-M Academic Publishing LLC., 2022. http://dx.doi.org/10.12737/1852468.
Texte intégralRésumé :
The textbook demonstrates the biochemical features of lactobacilli of different geographical races isolated from national dairy products of different countries and climatogeographic zones. The issues of the potential use of lactobacilli in the composition of dairy therapeutic and prophylactic products for gastrointestinal diseases and the creation of probiotics are considered. The literature data and the results of the authors' own research are analyzed.
Meets the requirements of the federal state educational standards of higher education of the latest generation.
It is intended for university students specializing in the food industry, medicine, and pharmaceutical manufacturing technologies. It can be used by specialists of various profiles who, by their occupation, need to understand reasonable nutrition, the role of microorganisms in the functioning of the digestive system, the occurrence of diseases and therapeutic effect, as well as to rethink the feasibility of using lactotherapy for therapeutic and prophylactic purposes in dysbiosis of different genesis instead of chemotherapy.
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Boreland, Paul C. A study of the Lactobacilli in wiltshire-cured vacuum packed bacon. [s.l : The author], 1985.
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B, Wood Brian J., et Holzapfel W. H, dir. The genera of lactic acid bacteria. London : Blackie Academic & Professional, 1995.
Trouver le texte intégralChapitres de livres sur le sujet "Lactobacillu"
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Barbés, Covadonga. « Lactobacilli ». Dans Therapeutic Microbiology, 19–33. Washington, DC, USA : ASM Press, 2014. http://dx.doi.org/10.1128/9781555815462.ch3.
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Gooch, Jan W. « Lactobacilli ». Dans Encyclopedic Dictionary of Polymers, 903. New York, NY : Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_14084.
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Bährle-Rapp, Marina. « Lactobacillus acidophilus ». Dans Springer Lexikon Kosmetik und Körperpflege, 308. Berlin, Heidelberg : Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/978-3-540-71095-0_5758.
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Bährle-Rapp, Marina. « Lactobacillus Ferment ». Dans Springer Lexikon Kosmetik und Körperpflege, 308. Berlin, Heidelberg : Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/978-3-540-71095-0_5761.
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Hammes, W. P., et R. F. Vogel. « The genus Lactobacillus ». Dans The Genera of Lactic Acid Bacteria, 19–54. Boston, MA : Springer US, 1995. http://dx.doi.org/10.1007/978-1-4615-5817-0_3.
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Bährle-Rapp, Marina. « Lactobacillus/Algae Ferment ». Dans Springer Lexikon Kosmetik und Körperpflege, 308. Berlin, Heidelberg : Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/978-3-540-71095-0_5759.
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Bährle-Rapp, Marina. « Lactobacillus/Lac Ferment ». Dans Springer Lexikon Kosmetik und Körperpflege, 309. Berlin, Heidelberg : Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/978-3-540-71095-0_5764.
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Bährle-Rapp, Marina. « Lactobacillus/Phophyridium Ferment ». Dans Springer Lexikon Kosmetik und Körperpflege, 309. Berlin, Heidelberg : Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/978-3-540-71095-0_5766.
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Bährle-Rapp, Marina. « Lactobacillus/Skeletonema Ferment ». Dans Springer Lexikon Kosmetik und Körperpflege, 309. Berlin, Heidelberg : Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/978-3-540-71095-0_5767.
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Pot, Bruno, Giovanna E. Felis, Katrien De Bruyne, Effie Tsakalidou, Konstantinos Papadimitriou, Jørgen Leisner et Peter Vandamme. « The genus Lactobacillus ». Dans Lactic Acid Bacteria, 249–353. Chichester, UK : John Wiley & Sons, Ltd, 2014. http://dx.doi.org/10.1002/9781118655252.ch19.
Texte intégralActes de conférences sur le sujet "Lactobacillu"
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AlBERMANI, Oruba K., Isrra Adnan Auda KHADHIM et Nebras Mohammed SAHI. « ANTIMICROBIAL SUSCEPTIBILITY PATTERN AND THE ANTAGONISTIC EFFECT OF LACTOBACILLUS IN FIGHTING SHIGELLA SPP. ISOLATED FROM DIARRHEIC CHILDREN ». Dans III.International Scientific Congress of Pure,Appliedand Technological Sciences. Rimar Academy, 2021. http://dx.doi.org/10.47832/minarcongress3-9.
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Background: Shigella is an major source of bacterial gastroenteritis in lack of health awareness in society. The handling of shigellos is mostly requires antibiotics. The using of probiotic of Lactic acid bacteria possess the counter effect against many dangerous bacterial pathogens which associated with gastroenteritis like Shigella spp. Aim: the purpose of this study to estimate the influence of lactic bacteria of the genus Lactobacillus on the population Shigella as a main pathogen involved in gastroenteritis in children. Patients and methods: A total of 50 stool specimens were collected during the period September2019 to January 2020 from diarrheic children patients age range(1-3)years. Standard bacteriological methods were used to isolate, identify, and determine the antimicrobial susceptibility pattern of Shigellaisolates, and we used fresh culture of Lactobacillus 24 h (previously isolated as member of fecal microbiota from healthy person and identified by molecular assay). Then we done centrifugation to obtain supernatant which have test bioactive materials like bacteriocin. These bacteriocin materials subjected to own antibacterial activity against other bacterial pathogen like Shigella spp. By using agar diffusion method . Results: All the 14 Shigella spp. isolates show 100% resistance to nalidixic acid,. cotrimoxazole , and High resistance to ciprofloxacin (85%), and moderate resistant of ampicillin (64%). In agar- well diffusion method indicated the high antagonistic activity of the strains of Lactobacillus 2, 3, and 4 isolated from health GI tract against all Shigella spp., as a result of their activity the total elimination of Shigella within 24 h was observed. conclusion: the Shigella spp. Strains exhibited antibiotic resistant against more one type of antiobiotic The lactobacilii strains tested during this study showed strong antimicrobial activity against Shigella spp. Key words: Shigellos is, Lactobacillus, 16S Rrna.
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Faskhutdinova, Elizaveta, Irina Milentyeva et Larisa Proskuryakova. « STUDY OF BIOCOMPATIBILITY OF PROBIOTIC STRAINS OF MICROORGANISMS IN ORDER TO CREATE A BIOLOGICALLY ACTIVE FOOD ADDITIVE ». Dans I International Congress “The Latest Achievements of Medicine, Healthcare, and Health-Saving Technologies”. Kemerovo State University, 2023. http://dx.doi.org/10.21603/-i-ic-136.
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The purpose of this work is to study the biocompatibility of probiotic strains Lactobacillus
plantarum B-1615, Lactobacillus brevis B-2429, Bacillus subtilis B-7918, Enterococcus faecium B5000 and Lactobacillus paracasei B-2430 to create a biologically active supplement. A drip technique
was used to study biocompatibility. It was found that biocompatibility is possessed by combinations of
strains Lactobacillus plantarum B-1615 and Lactobacillus brevis B-2429; Lactobacillus plantarum B1615 and Bacillus subtilis 21 B-7918; Lactobacillus plantarum B-1615 and Lactobacillus paracasei B2430; Lactobacillus brevis B-2429 and Enterococcus faecium B -5000; Lactobacillus brevis B-2429 and
Lactobacillus paracasei B-2430; Bacillus subtilis 21 B-7918 and Enterococcus faecium B-5000.
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M.A., Khidirova, Khushvaktov E.M., Mamatraimova M.M., Tuychiyev K.S., Chistyakov V.A., Pepoyan A.Z. et Miralimova Sh.M. « BIOENCAPSULATION OF PROBIOTIC BACTERIA IN BLACK SOLDIER (HERMETIA ILLUCENS) LARWAE ». Dans II INTERNATIONAL SCIENTIFIC AND PRACTICAL CONFERENCE "DEVELOPMENT AND MODERN PROBLEMS OF AQUACULTURE" ("AQUACULTURE 2022" CONFERENCE). DSTU-Print, 2022. http://dx.doi.org/10.23947/aquaculture.2022.160-164.
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The encapsulation capacity of the larvae of Hermetia illucens was investigated in the study. Determined the optimal dosage and time of administration of a multicomponent probiotic composition consisting of lactobacilli. The hatched larvae of Hermetia illucens were incubated with the addition of 0.1%, 0.2%, 0.4%, and 0.8% of the probiotic preparation at the beginning of the incubation and during the last 3 days of incubation. The most effective accumulation of lactobacilli was observed when 0.4% of the preparation was added to the feed during the last two days of cultivation. The largest number of lactobacilli achieved in the intestine of one larva was 2-6x106 CFU.
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Belova, N. V. « Influence of a new generation adaptogen and probiotic combination on sheep phagocytosis indicators ». Dans CURRENT STATE, PROBLEMS AND PROSPECTS OF THE DEVELOPMENT OF AGRARIAN SCIENCE. Federal State Budget Scientific Institution “Research Institute of Agriculture of Crimea”, 2020. http://dx.doi.org/10.33952/2542-0720-2020-5-9-10-125.
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The purpose of the research was to investigate the effect of the lithium ascorbate stress-protector and its complex with a probiotic based on lactobacilli on the phagocytic activity of blood leukocytes. In the course of this research, we found that lithium ascorbate stress-protector combined with probiotic lactobacilli strains reliably increases the phagocytic index of blood by 28.6 % and has a positive effect on the non-specific resistance and immunological status of sheep.
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DALCANTON, F., F. R. S. MACHADO JR, D. A. LONGHI, B. A. M. CARCIOFI, J. B. LAURINDO et G. M. F. ARAGÃO. « MATHEMATICAL MODELING OF LACTOBACILLUS VIRIDESCENS AND LACTOBACILLUS SAKEI GROWTH AT SIX DIFFERENT TEMPERATURES ». Dans XX Congresso Brasileiro de Engenharia Química. São Paulo : Editora Edgard Blücher, 2015. http://dx.doi.org/10.5151/chemeng-cobeq2014-1407-19439-141560.
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D.S., Chelombitskaya, Rudoy D.V., Olshevskaya A.V., Odabashyan M.Yu. et Vershinina A.V. « INFLUENCE OF PROBIOTIC BACTERIA LACTOBACILLUS RHAMNOSUS L108 ON HOST GENE EXPRESSION (IN THE CAENORHABDITIS ELEGANS MODEL). » Dans II INTERNATIONAL SCIENTIFIC AND PRACTICAL CONFERENCE "DEVELOPMENT AND MODERN PROBLEMS OF AQUACULTURE" ("AQUACULTURE 2022" CONFERENCE). DSTU-Print, 2022. http://dx.doi.org/10.23947/aquaculture.2022.165-167.
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The article presents a study of the effect of the probiotic bacterium Lactobacillus rhamnosus L108 on the expression of host longevity genes in the Caenorhabditis elegans model. The study found that the Lactobacillus rhamnosus L108 strain increased the lifespan of Caenorhabditis elegans by 9.6%. Also, when analyzing longevity genes, an increase in the level of expression of the sir-2.1, skn-1, and daf-16 genes, which underlie the regulation of conservative signaling protective pathways of insulin/insulin-like factor-1 and p38 MAPK, was observed.
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Silva, Karolaine Moura da, Allyson de Andrade Mendonça et Marcos Antônio de Morais Junior. « ANÁLISE DO EFEITO DA SUPLEMENTAÇÃO DE AMINOÁCIDOS NA CIM DA BACTÉRIA LACTOBACILLUS HALOTOLERANS ». Dans XXVII Semana de Biomedicina Inovação e Ciência. Editora IME, 2021. http://dx.doi.org/10.51161/9786588884119/30.
Texte intégralRésumé :
Introdução: A microbiota humana é composta por vários gêneros bacterianos, dentre eles estão os Lactobacillus(1). Além do corpo humano, estas bactérias podem estar presentes nos processos fermentativos para produção de etanol, sendo responsáveis por boa parte da contaminação do mosto fermentativo(4). A utilização de tratamentos físicos e químicos, como administração de antimicrobianos, é realizada para o controle bacteriano. Entretanto, nas últimas décadas, resistência a diversos antibióticos utilizados na indústria foram surgindo(2). Em estudos anteriores foi identificado que cepas de Lactobacillus vini cultivadas em meio MRS suplementado com o aminoácido cisteína mostram-se mais resistentes ao antibiótico eritromicina(³). Objetivos: Assim, este trabalho teve como objetivo analisar o efeito dos vinte aminoácidos sobre a CIM, para o antibiótico tetraciclina, da espécie bacteriana Lactobacillus halotolerans, pertencente do gênero Lactobacillus. Métodos: Foi determinada a concentração inibitória mínima (CIM) da espécie L. halotolerans utilizando a metodologia de microdiluição em caldo para o antibiótico tetraciclina, na ausência ou na presença de cada um dos 20 aminoácidos na concentração de 40mM. Resultados: Foi observado que na maioria dos casos, a suplementação com os aminoácidos teve efeito neutro ou induziu um leve aumento da tolerância à droga. Os aminoácidos alanina, arginina, histidina, isoleucina, leucina, fenilalanina, triptofano e valina aumentaram o CIM da droga em 2x. Enquanto que os aminoácidos aspartato, cisteína, glutamato, glutamina, glicina, metionina, prolina, serina, treonina e tirosina não modificaram o CIM para tetraciclina. O aminoácido lisina foi o único que teve efeito de diminuição da tolerância, reduzindo-a em 2x. Já a asparagina foi responsável por um aumento de 8x em comparação ao CIM original, sendo o aminoácido que mais aumentou a tolerância do microrganismo à tetraciclina. Conclusões: Com isso, concluímos que os aminoácidos podem vir a causar uma modificação na CIM da espécie de Lactobacillus halotolerans, tanto aumentando ou diminuindo a sua tolerância, sendo válido estudar mais a fundo em demais microrganismos e qual mecanismo por trás de tais efeitos. ISBN: 978-
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Barrera, Cristina, Cristina Burca, Lucía Seguí et Noelia Betoret. « Changes in antioxidant and probiotic properties of a freeze-dried apple snack during storage ». Dans 21st International Drying Symposium. Valencia : Universitat Politècnica València, 2018. http://dx.doi.org/10.4995/ids2018.2018.7880.
Texte intégralRésumé :
This research developed an apple snack with potential probiotic effect (> 107 CFU/g) by combining vacuum impregnation with Lactobacillus salivarius spp. salivarius (CECT 4063) and freeze-drying. Throughout storage (30 days), both the lactobacillus viability and the total flavonoids content decreased. Trehalose adition (10% by weight) to the impregnation liquid and/or its homogenization at 100 MPa accelerated the loss of cell viability but delayed flavonoids degradation and promoted an increase in the amount of phenols and total antioxidants. Keywords: L. salivarius spp. salivarius; homogenization; trehalose; freeze-drying; antioxidants.
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Acosta-Piantini, Elsa Maritza, M. Carmen Villaran et J. Ignacio Lombraña. « Stabilization of encapsulated probiotics from the bacterium Lactobacillus casei by different drying techniques ». Dans 21st International Drying Symposium. Valencia : Universitat Politècnica València, 2018. http://dx.doi.org/10.4995/ids2018.2018.7744.
Texte intégralRésumé :
The main objective of this work is to encapsulate and dry the bacterium probiotic Lactobacillus casei applying three different drying techniques (lyophilization, fluidized bed and flash freeze drying) as well as to evaluate their viability during storage in the dark at 20ºC and 34% relative humidity for 28 days. In addition, to compare viability of the bacterium processed with flash freeze drying with cryoprotectant (skim milk) and without cryoprotectant. In the case of flash freeze drying, the final level of viability shows the potential of this drying technique with much less operating costs than lyophilization. Keywords: Encapsulated, probiotics, lactobacillus, casei, drying
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Milentyeva, Irina, Anastasiya Fedorova et Yu A. Erofeeva. « RESEARCH AND DEVELOPMENT OF PROBIOTIC SUPPLEMENTS BASED ON METABOLITES OF BIFIDOBACTERIUM AND LACTOBACILLUS BACTERIA ». Dans I International Congress “The Latest Achievements of Medicine, Healthcare, and Health-Saving Technologies”. Kemerovo State University, 2023. http://dx.doi.org/10.21603/-i-ic-89.
Texte intégralRapports d'organisations sur le sujet "Lactobacillu"
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Nemska, Veronica, Nelly Georgieva, Jeny Miteva-Staleva, Ekaterina Krumova et Svetla Danova. Antifungal Activity of Lactobacillus spp. from Traditional Bulgarian Dairy Products. "Prof. Marin Drinov" Publishing House of Bulgarian Academy of Sciences, décembre 2019. http://dx.doi.org/10.7546/crabs.2019.12.10.
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Taylor, Craig. Physical and kinetic properties of dihydroorotate dehydrogenase from Lactobacillus bulgaricus. Portland State University Library, janvier 2000. http://dx.doi.org/10.15760/etd.62.
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Barstad, Louise. Purification and characterization of NADH oxidase and peroxidase from Lactobacillus casei. Portland State University Library, janvier 2000. http://dx.doi.org/10.15760/etd.2785.
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Indrio, Flavia. Beneficios de Lactobacillus reuteri DSM 17983 en los trastornos digestivos funcionales de la infancia. Buenos Aires : siicsalud.com, février 2015. http://dx.doi.org/10.21840/siic/144143.
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Cheng, Yonglang, Peng Zeng, Zhiwei Huang, Hao Shi, Tianying Cai, Tongxi Li, Yifan Chen, Wenguang Fu et Qiu Li. Lactobacillus reuteri alleviates lipid levels in patients with hypercholesterolemia : a meta-analysis of randomized controlled trials. INPLASY - International Platform of Registered Systematic Review and Meta-analysis Protocols, avril 2022. http://dx.doi.org/10.37766/inplasy2022.4.0160.
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Osman, Mohamed, Judith Stabel, Jesse M. Hostetter, Daniel S. Nettleton et Donald C. Beitz. Probiotic Lactobacillus acidophilus strain NP51® Curtails the Progression of Mycobacterium avium Subspecies paratuberculosis (MAP) Infection in Balb/c mice. Ames (Iowa) : Iowa State University, janvier 2011. http://dx.doi.org/10.31274/ans_air-180814-66.
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Osman, Mohamed, Judith Stabel, Jesse M. Hostetter, Daniel S. Nettleton et Donald C. Beitz. Prevention of Mycobacterium avium Subspecies paratuberculosis (MAP) Infection in Balb/c mice by Feeding Lactobacillus acidophilus Strain NP-51®. Ames (Iowa) : Iowa State University, janvier 2010. http://dx.doi.org/10.31274/ans_air-180814-944.
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Weinberg, Zwi G., Adegbola Adesogan, Itzhak Mizrahi, Shlomo Sela, Kwnag Jeong et Diwakar Vyas. effect of selected lactic acid bacteria on the microbial composition and on the survival of pathogens in the rumen in context with their probiotic effects on ruminants. United States Department of Agriculture, janvier 2014. http://dx.doi.org/10.32747/2014.7598162.bard.
Texte intégralRésumé :
This research project was performed in context of the apparent probiotic effect of selected lactic acid bacteria (LAB) silage inoculants on the performance of ruminants (improved feed intake, faster live-weight gain, higher milk yields and improved feed efficiency). The overall objective was to find out how LAB affect ruminant performance. The project included several “chapters” as follows: 1. The effect of LAB silage inoculants on the survival of detrimental bacteria in rumen fluid, in vitro study (Weinberg et al., The Volcani Center). An in vitro model was developed to study the interaction between selected LAB and an E. coli strain tagged with green fluorescence protein (GFP) in buffered RF. Results indicated that both LAB inoculants and E. coli survived in the RF for several days; both LAB inoculants and LAB-treated silages did not affect survival of E. coli in rumen fluid in vitro. The effect of feeding baled wheat silages treated with or without three selected LAB silage inoculants on the performance of high-lactating cows (Weinberg et al., The Volcani Center). Treatments included control (no additive), Lacobacillusbuchneri40788 (LB), Lactobacillus plantarumMTD1 40027 (LP) and Pediococcuspentosaceus30168 (PP), each applied at 10⁶ cfu/g FM. The silages were included in the TMR of 32 high milking Holstein cows in a controlled feeding experiment. All baled silages were of good quality. The LB silage had the numerically highest acetic acid and were the most stable upon aerobic exposure. The cows fed the LB silages had the highest daily milk yields, percent milk fat and protein. The microbiome of baled wheat silages and changes during ensiling of wheat and corn (Sela et al., The Volcani Center). Bacterial community of the baled silages was dominated mainly of two genera in total, dominated by Lactobacillus and Clostridium_sensu_stricto_12 with 300 other genera at very low abundance. Fungal community was composed mainly of two genera in total, dominated by Candida and Monascuswith 20 other genera at very low abundance. In addition, changes in the microbiome during ensiling of wheat and corn with and without addition of L. plantarumMTD1 was studied in mini-silos. Overall 236 bacterial genera were identified in the fresh corn but after 3 months Lactobacillus outnumbered all other species by acquiring 95% of relative abundance. The wheat silage samples are still under analysis. The effect of applying LAB inoculants at ensiling on survival of E. coli O157:H7 in alfalfa and corn silages(Adesogan et al., University of Florida). E. coli (10⁵ cfu/g) was applied to fresh alfalfa and corn at ensiling with or without L. plantarumor L. buchneri. The pathogen was added again after about 3 moths at the beginning of an aerobic exposure period. The inoculants resulted in faster decrease in pH as compared with the control (no additives) or E. coli alone and therefore, the pathogen was eliminated faster from these silages. After aerobic exposure the pathogen was not detected in the LAB treated silages, whereas it was still present in the E. coli alone samples. 5. The effect of feeding corn silage treated with or without L. buchnerion shedding of E. coli O157:H7 by dairy cows (Adesogan et al., UFL). BARD Report - Project 4704 Page 2 of 12 Five hundred cows from the dairy herd of the University of Florida were screened for E. coli shedding, out of which 14 low and 13 high shedders were selected. These cows were fed a total mixed ration (TMR) which was inoculated with E. coli O157:H7 for 21 days. The TMR included corn silage treated with or without L. buchneri. The inoculated silages were more stable upon aerobic exposure than the control silages; the silage inoculant had no significant effect on any milk or cow blood parameters. However, the silage inoculant tended to reduce shedding of E. coli regardless of high or low shedders (p = 0.06). 6. The effect of feeding baled wheat silages treated with or without three selected LAB silage inoculants on the rumen microbiome (Mizrahi et al., BGU). Rumen fluid was sampled throughout the feeding experiment in which inoculated wheat silages were included in the rations. Microbial DNA was subsequently purified from each sample and the 16S rRNA was sequenced, thus obtaining an overview of the microbiome and its dynamic changes for each experimental treatment. We observed an increase in OTU richness in the group which received the baled silage inoculated with Lactobacillus Plantarum(LP). In contrast the group fed Lactobacillus buchneri(LB) inoculated silage resulted in a significant decrease in richness. Lower OTU richness was recently associated in lactating cows with higher performance (Ben Shabatet al., 2016). No significant clustering could be observed between the different inoculation treatments and the control in non metric multi-dimentional scaling, suggesting that the effect of the treatments is not the result of an overall modulation of the microbiome composition but possibly the result of more discrete interactions. Significant phylum level changes in composition also indicates that no broad changes in taxa identity and composition occurred under any treatment A more discrete modulation could be observed in the fold change of several taxonomic groups (genus level analysis), unique to each treatment, before and after the treatment. Of particular interest is the LB treated group, in which several taxa significantly decreased in abundance. BARD Report - Project 4704 Page 3 of 12
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Weinberg, Zwi G., Richard E. Muck, Nathan Gollop, Gilad Ashbell, Paul J. Weimer et Limin Kung, Jr. effect of lactic acid bacteria silage inoculants on the ruminal ecosystem, fiber digestibility and animal performance. United States Department of Agriculture, septembre 2003. http://dx.doi.org/10.32747/2003.7587222.bard.
Texte intégralRésumé :
The overall objective of the whole research was to elucidate the mechanisms by which LAB silage inoculants enhance ruminant performance. The results generated will permit the development of better silage inoculants that maximize both silage preservation and animal performance. For this one-year BARD feasibility study, the objectives were to: 1. determine whether lactic acid bacteria (LAB) used in inoculants for silage can survive in rumen fluid (RF) 2.select the inoculants that survived best, and 3. test whether LAB silage inoculants produce bacteriocins-like substances. The most promising strains will be used in the next steps of the research. Silage inoculants containing LAB are used in order to improve forage preservation efficiency. In addition, silage inoculants enhance animal performance in many cases. This includes improvements in feed intake, liveweight gain and milk production in 25-40% of studies reviewed. The cause for the improvement in animal performance is not clear but appears to be other than direct effect of LAB inoculants on silage fermentation. Results from various studies suggest a possible probiotic effect. Our hypothesis is that specific LAB strains interact with rumen microorganisms which results in enhanced rumen functionality and animal performance. The first step of the research is to determine whether LAB of silage inoculants survive in RF. Silage inoculants (12 in the U.S. and 10 in Israel) were added to clarified and strained RF. Inoculation rate was 10 ⁶ (clarified RF), 10⁷ (strained RF) (in the U.S.) and 10⁷, 10⁸ CFU ml⁻¹ in Israel (strained RF). The inoculated RF was incubated for 72 and 96 h at 39°C, with and without 5 g 1⁻¹ glucose. Changes in pH, LAB numbers and fermentation products were monitored throughout the incubation period. The results indicated that LAB silage inoculants can survive in RF. The inoculants with the highest counts after 72 h incubation in rumen fluid were Lactobacillus plantarum MTD1 and a L. plantarum/P. cerevisiae mixture (USA) and Enterococcus faecium strains and Lactobacillus buchneri (Israel). Incubation of rumen fluid with silage LAB inoculants resulted in higher pH values in most cases as compared with that of un-inoculated controls. The magnitude of the effect varied among inoculants and typically was enhanced with the inoculants that survived best. This might suggest the mode of action of LAB silage inoculants in the rumen as higher pH enhances fibrolytic microorganisms in the rumen. Volatile fatty acid (VFA) concentrations in the inoculated RF tended to be lower than in the control RF after incubation. However, L. plalltarull1 MTDI resulted in the highest concentrations of VFA in the RF relative to other inoculants. The implication of this result is not as yet clear. In previous research by others, feeding silages which were inoculated with this strain consistently enhanced animal performance. These finding were recently published in Weinberg et.al.. (2003), J. of Applied Microbiology 94:1066-1071 and in Weinberg et al.. (2003), Applied Biochemistry and Biotechnology (accepted). In addition, some strains in our studies have shown bacteriocins like activity. These included Pediococcus pentosaceus, Enterococcus faecium and Lactobacillus plantarum Mill 1. These results will enable us to continue the research with the LAB strains that survived best in the rumen fluid and have the highest potential to affect the rumen environment.
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Asvapathanagul, Pitiporn, Leanne Deocampo et Nicholas Banuelos. Biological Hydrogen Gas Production from Food Waste as a Sustainable Fuel for Future Transportation. Mineta Transportation Institute, juillet 2022. http://dx.doi.org/10.31979/mti.2021.2141.
Texte intégralRésumé :
In the global search for the right alternative energy sources for a more sustainable future, hydrogen production has stood out as a strong contender. Hydrogen gas (H2) is well-known as one of the cleanest and most sustainable energy sources, one that mainly yields only water vapor as a byproduct. Additionally, H2 generates triple the amount of energy compared to hydrocarbon fuels. H2 can be synthesized from several technologies, but currently only 1% of H2 production is generated from biomass. Biological H2 production generated from anaerobic digestion is a fraction of the 1%. This study aims to enhance biological H2 production from anaerobic digesters by increasing H2 forming microbial abundance using batch experiments. Carbon substrate availability and conversion in the anaerobic processes were achieved by chemical oxygen demand and volatile fatty acids analysis. The capability of the matrix to neutralize acids in the reactors was assessed using alkalinity assay, and ammonium toxicity was monitored by ammonium measurements. H2 content was also investigated throughout the study. The study's results demonstrate two critical outcomes, (i) food waste as substrate yielded the highest H2 gas fraction in biogas compared to other substrates fed (primary sludge, waste activated sludge and mixed sludge with or without food waste), and (ii) under normal operating condition of anaerobic digesters, increasing hydrogen forming bacterial populations, including Clostridium spp., Lactococcus spp. and Lactobacillus spp. did not prolong biological H2 recovery due to H2 being taken up by other bacteria for methane (CH4) formation. Our experiment was operated under the most optimal condition for CH4 formation as suggested by wastewater operational manuals. Therefore, CH4-forming bacteria possessed more advantages than other microbial populations, including H2-forming groups, and rapidly utilized H2 prior to methane synthesis. This study demonstrates H2 energy renewed from food waste anaerobic digestion systems delivers opportunities to maximize California’s cap-and-trade program through zero carbon fuel production and utilization.