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Sample records for bifidobacterium lactis dn-173

  1. Fermented Milk Containing Bifidobacterium lactis DN-173 010 in Childhood Constipation: A Randomized, Double-Blind, Controlled Trial

    NARCIS (Netherlands)

    Tabbers, Merit M.; Chmielewska, Ania; Roseboom, Maaike G.; Crastes, Nolwenn; Perrin, Catherine; Reitsma, Johannes B.; Norbruis, Obbe; Szajewska, Hania; Benninga, Marc A.

    2011-01-01

    BACKGROUND: Constipation is a frustrating symptom affecting 3% of children worldwide. A fermented dairy product containing Bifidobacterium lactis strain DN-173 010 was effective in increasing stool frequency in constipated women. Our aim was to assess the effects of this product in constipated

  2. Effect of the consumption of a fermented dairy product containing Bifidobacterium lactis DN-173 010 on constipation in childhood: a multicentre randomised controlled trial (NTRTC: 1571).

    Science.gov (United States)

    Tabbers, Merit M; Chmielewska, Ania; Roseboom, Maaike G; Boudet, Claire; Perrin, Catherine; Szajewska, Hania; Benninga, Marc A

    2009-03-18

    Constipation is a frustrating symptom affecting 3% of children worldwide. Randomised controlled trials show that both polyethylene glycol and lactulose are effective in increasing defecation frequency in children with constipation. However, in 30-50%, these children reported abdominal pain, bloating, flatulence, diarrhoea, nausea and bad taste of the medication. Two recent studies have shown that the fermented dairy product containing Bifidobacterium lactis strain DN-173 010 is effective in increasing stool frequency in constipation-predominant irritable bowel syndrome patients with a defecation frequency fermented dairy product is effective in the treatment of constipated children with a defecation frequency fermented dairy product containing Bifidobacterium lactis DN-173 010 or a control product, twice a day, for 3 weeks. During the study all children are instructed to try to defecate on the toilet for 5-10 minutes after each meal (3 times a day) and daily complete a standardized bowel diary. Primary endpoint is stool frequency. Secondary endpoints are stool consistency, faecal incontinence frequency, pain during defecation, digestive symptoms (abdominal pain, flatulence), adverse effects (nausea, diarrhoea, bad taste) and intake of rescue medication (Bisacodyl). Rate of success and rate of responders are also evaluated, with success defined as > or = 3 bowel movements per week and or = 3 on the last week of product consumption. To demonstrate that the success percentage in the intervention group will be 35% and the success percentage in the control group (acidified milk without ferments, toilet training, bowel diary) will be 15%, with alpha 0.05 and power 80%, a total sample size of 160 patients was calculated. This study is aimed to show that the fermented dairy product containing Bifidobacterium lactis strain DN-173 010 is effective in increasing stool frequency after 3 weeks of product consumption in children with functional constipation and a defecation

  3. Effect of the consumption of a fermented dairy product containing Bifidobacterium lactis DN-173 010 on constipation in childhood: a multicentre randomised controlled trial (NTRTC: 1571

    Directory of Open Access Journals (Sweden)

    Perrin Catherine

    2009-03-01

    Full Text Available Abstract Background Constipation is a frustrating symptom affecting 3% of children worldwide. Randomised controlled trials show that both polyethylene glycol and lactulose are effective in increasing defecation frequency in children with constipation. However, in 30–50%, these children reported abdominal pain, bloating, flatulence, diarrhoea, nausea and bad taste of the medication. Two recent studies have shown that the fermented dairy product containing Bifidobacterium lactis strain DN-173 010 is effective in increasing stool frequency in constipation-predominant irritable bowel syndrome patients with a defecation frequency Methods/design It is a two nation (The Netherlands and Poland double-blind, placebo-controlled randomised multicentre trial in which 160 constipated children (age 3–16 years with a defecation frequency Bifidobacterium lactis DN-173 010 or a control product, twice a day, for 3 weeks. During the study all children are instructed to try to defecate on the toilet for 5–10 minutes after each meal (3 times a day and daily complete a standardized bowel diary. Primary endpoint is stool frequency. Secondary endpoints are stool consistency, faecal incontinence frequency, pain during defecation, digestive symptoms (abdominal pain, flatulence, adverse effects (nausea, diarrhoea, bad taste and intake of rescue medication (Bisacodyl. Rate of success and rate of responders are also evaluated, with success defined as ≥ 3 bowel movements per week and ≤1 faecal incontinence episode over the last 2 weeks of product consumption and responder defined as a subject reporting a stool frequency ≥ 3 on the last week of product consumption. To demonstrate that the success percentage in the intervention group will be 35% and the success percentage in the control group (acidified milk without ferments, toilet training, bowel diary will be 15%, with alpha 0.05 and power 80%, a total sample size of 160 patients was calculated. Conclusion This

  4. Effect of a fermented milk containing Bifidobacterium lactis DN-173010 on Chinese constipated women.

    Science.gov (United States)

    Yang, Yue-Xin; He, Mei; Hu, Gang; Wei, Jie; Pages, Philippe; Yang, Xian-Hua; Bourdu-Naturel, Sophie

    2008-10-28

    To investigate the effect of a fermented milk containing Bifidobacterium lactis DN-173010 and yogurt strains (BIO(R)) on adult women with constipation in Beijing. A total of 135 adult females with constipation were randomly allocated to consume for 2 wk either 100 g of the test fermented milk or 100 g of an acidified milk containing non-living bacteria (control). Stool frequency, defecation condition scores, stool consistency and food intake were recorded at baseline and after 1 and 2 wk in an intention-to-treat population of 126 subjects. In parallel, safety evaluation parameters were performed. At baseline, no differences were found between groups. Following consumption of test product, stool frequency was significantly increased after 1 wk (3.5 +/- 1.5 vs 2.4 +/- 0.6, P food intake did not change between the two groups, and safety parameters of the subjects were within normal ranges. This study suggests a beneficial effect of a fermented milk containing B. lactis DN-173010 on stool frequency, defecation condition and stool consistency in adult women with constipation constipated women after 1 and 2 wk of consumption.

  5. Diversity of the subspecies Bifidobacterium animalis subsp. lactis.

    Science.gov (United States)

    Bunesova, Vera; Killer, Jiri; Javurkova, Barbora; Vlkova, Eva; Tejnecky, Vaclav; Musilova, Sarka; Rada, Vojtech

    2017-04-01

    Strains of Bifidobacterium animalis subsp. lactis are well-known health-promoting probiotics used commercially. B. animalis subsp. lactis has been isolated from different sources, and little is known about animal isolates of this taxon. The aim of this study was to examine the genotypic and phenotypic diversity between B. animalis subsp. lactis strains different animal hosts including Cameroon sheep, Barbary sheep, okapi, mouflon, German shepard and to compare to BB12, food isolates and the collection strain DSM 10140. Ten strains of B. animalis subsp. lactis from different sources were characterised by phenotyping, fingerprinting, and multilocus sequence typing (MLST). Regardless of origin, MLST and phylogenetic analyses revealed a close relationship between strains of B. animalis subsp. lactis with commercial and animal origin with the exception of isolates from ovine cheese, mouflon and German Shepard dog. Moreover, isolates from dog and mouflon showed significant differences in fermentation profiles and peptide mass fingerprints (MALDI-TOF). Results indicated phenotypic and genotypic diversity among strains of B. animalis subsp. lactis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Predictive modeling of Bifidobacterium animalis subsp. lactis Bb-12 growth in cow’s, goat’s and soy milk

    Directory of Open Access Journals (Sweden)

    Vedran Slačanac

    2013-11-01

    Full Text Available The aim of this study was to use a predictive model to analyse the growth of a probiotic strain Bifidobacterium animalis subsp. lactis Bb-12 in cow’s, goat’s and soy milk. The Gompertz model was used, and the suitability of the model was estimated by the Schnute algorithm. Except for the analysis of Bifidobacterium animalis subsp. lactis Bb-12 growth, the Gompertz model was also used for the analysis of pH changes during the fermentation process. Experimental results, as well as the values of kinetic parameters obtained in this study, showed that the highest growth rate of Bifidobacterium animalis subsp. lactis Bb-12 was obtained in goat’s milk, and the lowest in soy milk. Contrary to the growth of Bifidobacterium animalis subsp. lactis Bb-12, pH decreased faster in soy milk than in cow’s milk. The highest rate of pH decrease was also observed in goat’s milk, which is in correspondence with results of various previous studies. The Gompertz model proved to be highly suitable for analysing the course and the fermentation kinetics in these three kinds of milk, and might be used to analyse the growth kinetics of other probiotic and starter cultures in milk.

  7. Stability of free and immobilized Lactobacillus acidophilus and Bifidobacterium lactis in acidified milk and of immobilized B. lactis in yoghurt Estabilidade de Lactobacillus acidophilus e Bifidobacterium lactis nas formas livre e imobilizada em leite acidificado e de B. lactis imobilizado em iogurte

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    Carlos Raimundo Ferreira Grosso

    2004-06-01

    Full Text Available This study evaluated the stability of Bifidobacterium lactis (Bb-12 and of Lactobacillus acidophilus (La-05 both free and immobilized in calcium alginate, in milk and in acidified milk (pH 5.0, 4.4 and 3.8. The stability of immobilized B. lactis in yoghurt (fermented to pH 4.2, during 28 days of refrigerated storage was also evaluated. The efficiency of two culture media (modified MRS agar and Reinforced Clostridial Agar plus Prussian Blue for counting of B. lactis in yoghurt was determined. Lee's agar was used to count Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus when B. lactis were counted in the MRS medium. B. lactis and L. acidophilus in both free and immobilized forms presented satisfactory rates of survival in milk and acidified milk because the average reduction of the population was only one log cycle after 21 days of storage. The number of viable cells of immobilized B. lactis in yoghurt presented a gradual decline throughout the storage period, passing from 10(8 cfu/ml to no count after 28 days of storage. When the cultures were not in equilibrium just the selective medium was efficient in counting B. lactis in yoghurt. The results showed that both microorganisms can be added to milk and acidified milk, because their population was only slightly affected during storage. The presence of traditional culture of yoghurt seems to be harmful for survival of immobilized B. lactis and the immobilization in calcium alginate failed as an effective barrier to protect the cells in all analysed treatments.Este trabalho avaliou a estabilidade de Bifidobacterium lactis (Bb-12 e de Lactobacillus acidophilus (La-05 nas formas livre e imobilizada em alginato de cálcio, em leite e leite acidificado (pHs 5.0, 4.4 e 3.8, e a estabilidade de B. lactis imobilizado em iogurte (fermentado até pH 4.2, durante 28 dias de estocagem refrigerada. Também foi estudada a eficiência de dois meios de cultura (ágar MRS modificado e

  8. Insights into physiological traits of Bifidobacterium animalis subsp. lactis BB-12 through membrane proteome analysis

    DEFF Research Database (Denmark)

    Gilad, Ofir; Hjernø, Karin; Østerlund, Eva Christina

    2012-01-01

    Bifidobacterium animalis subsp. lactis BB-12 is a widely used probiotic strain associated with a variety of health-promoting traits. There is, however, only limited knowledge available regarding the membrane proteome and the proteins involved in oligosaccharide transport in BB-12. We applied two...

  9. Effect of a fermented milk containing Bifidobacterium animalis DN-173 010 on the health-related quality of life and symptoms in irritable bowel syndrome in adults in primary care: a multicentre, randomized, double-blind, controlled trial.

    Science.gov (United States)

    Guyonnet, D; Chassany, O; Ducrotte, P; Picard, C; Mouret, M; Mercier, C-H; Matuchansky, C

    2007-08-01

    Health-related quality of life (HRQoL) has been rarely evaluated as a primary endpoint in the assessment of the effect of probiotics on the irritable bowel syndrome (IBS). To study the effects of fermented milk containing Bifidobacterium animalis DN-173 010 and yoghurt strains on the IBS in a multicentre, double-blind, controlled trial. A total of 274 primary care adults with constipation-predominant IBS (Rome II) were randomized to consume for 6 weeks either the test fermented milk or a heat-treated yoghurt (control). HRQoL and digestive symptoms were assessed after 3 and 6 weeks on an intention-to-treat population of 267 subjects. The HRQoL discomfort score, the primary endpoint, improved (P food on discomfort HRQoL score and bloating in constipation-predominant IBS, and on stool frequency in subjects with <3 stools/week.

  10. Does the scientific evidence support the advertising claims made for products containing Lactobacillus casei and Bifidobacterium lactis? A systematic review.

    Science.gov (United States)

    Meléndez-Illanes, Lorena; González-Díaz, Cristina; Chilet-Rosell, Elisa; Álvarez-Dardet, Carlos

    2016-09-01

    To analyse the scientific evidence that exists for the advertising claims made for two products containing Lactobacillus casei and Bifidobacterium lactis and to conduct a comparison between the published literature and what is presented in the corporate website. Systematic review, using Medline through Pubmed and Embase. We included human clinical trials that exclusively measured the effect of Lactobacillus casei or Bifidobacterium lactis on a healthy population, and where the objective was related to the health claims made for certain products in advertising. We assessed the levels of evidence and the strength of the recommendation according to the classification criteria established by the Oxford Centre for Evidence Based Medicine (CEBM). We also assessed the outcomes of the studies published on the website that did not appear in the search. Of the 440 articles identified, 16 met the inclusion criteria. Only four (25%) of these presented a level of evidence of 1b and a recommendation grade of A, all corresponding to studies on product containing Bifidobacterium lactis, and only 12 of the 16 studies were published on the corporate website (47). There is insufficient scientific evidence to support the health claims made for these products, especially in the case of product containing Lactobacillus casei. © The Author 2015. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  11. Consumption of Yogurt Containing Probiotic Bifidobacterium Lactis Reduces Streptococcus mutans in Orthodontic Patients

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    Armelia Sari Widyarman

    2018-01-01

    Full Text Available Background: Probiotic bacteria is commonly used as a food supplement intended to benefit the host by improving intestinal bacterial balance. Probiotics have also been investigated from the perspective of oral health. Objectives: The purpose of this study was to investigate the effect of daily intake of yogurt containing probiotic Bifidobacterium animalis subsp. lactis BB-12 (B. lactis on salivary Streptococcus mutans (S. mutans counts in patients undergoing fixed orthodontic treatment. Methods: Saliva samples were collected from each subject (n = 7; mean age, 21 years using spitting method in centrifuge tubes at baseline and two weeks after daily probiotic yogurt consumption. B. lactis BB-12 and S. mutans ATCC 25175 were cultured in BHI-broth (37ºC, anaerobic conditions. After 48-h incubation, the number of colonies on each dilution plate was used to extrapolate a standard curve. The total number of target DNA molecules were identified using real-time PCR followed by SYBR Green reagents and 16S rRNA gene specific primers S. mutans and B. lactis BB-12. Data were analyzed statistically using paired-sample t-tests. Results: Statistical evaluation indicated that there was a significant reduction in the presence of S. mutans before probiotic yogurt consumption, (4.73 ± 1.43 log10 CFU/mL and after two weeks of daily consumption of probiotic yogurt, (4.03 ± 0.77 log10 CFU/mL, p=0.001. Moreover, no B. lactis was found in the saliva of any of the subjects before probiotic consumption, but after two weeks of consumption, B. lactis was found in the saliva of four subjects. Conclusions: Consuming probiotic yogurt containing B. lactis reduced the quantity of S. mutans in the saliva of subjects during fixed orthodontic treatment. Thus, the probiotic bacteria could be beneficial in improving oral health.

  12. Analysis of the human intestinal epithelial cell transcriptional response to Lactobacillus acidophilus, Lactobacillus salivarius, Bifidobacterium lactis and Escherichia coli

    DEFF Research Database (Denmark)

    Putaala, H; Barrangou, R; Leyer, G J

    2010-01-01

    a comparative analysis of the global in vitro transcriptional response of human intestinal epithelial cells to Lactobacillus acidophilus NCFM™, Lactobacillus salivarius Ls-33, Bifidobacterium animalis subsp. lactis 420, and enterohaemorrhagic Escherichia coli O157:H7 (EHEC). Interestingly, L. salivarius Ls-33...

  13. Fermentation of protopanaxadiol type ginsenosides (PD) with probiotic Bifidobacterium lactis and Lactobacillus rhamnosus.

    Science.gov (United States)

    Tan, Joanne Sh; Yeo, Chia-Rou; Popovich, David G

    2017-07-01

    Ginsenosides are believed to be the principal components behind the pharmacological actions of ginseng, and their bioactive properties are closely related to the type, position, and number of sugar moieties attached to the aglycone; thus, modification of the sugar chains may markedly change their biological activities. In this study, major protopanaxadiol type ginsenosides (PD) Rb1, Rc, and Rb2 were isolated from Panax ginseng and were transformed using two probiotic strains namely Bifidobacterium lactis Bi-07 and Lactobacillus rhamnosus HN001 to obtain specific deglycosylated ginsenosides. It was demonstrated that B. lactis transformed ginsenosides Rb1, Rc, and Rb2 to Rd within 1 h of fermentation and rare ginsenoside F2 by the conversion of Rd after 12-h fermentation. The maximum Rd concentration was 147.52 ± 1.45 μg/mL after 48-h fermentation as compared to 45.85 ± 0.71 μg/mL before fermentation. In contrast, L. rhamnosus transformed Rb1, Rc, and Rb2 into Rd as the final metabolite after 72-h fermentation. B. lactis displayed significantly (p fermentation. The present study suggests that the fermentation of major PD type ginsenosides with B. lactis Bi-07 may serve as an effective means to afford bioactive deglycosylated ginsenosides and to create novel ginsenoside extracts.

  14. Estudo da viabilidade de Bifidobacterium animalis ssp. lactis em suco de Yacon

    OpenAIRE

    Watanabe, Felipe Miguel Farion

    2013-01-01

    Resumo: A maioria dos produtos probióticos são elaborados à base de leite, com desvantagens aos consumidores intolerantes à lactose, tornando assim produtos probióticos não lácteos vantajosos. O yacon é uma planta que acumula em suas raízes compostos prebióticos conhecidos como frutooligossacarídeos. O objetivo deste trabalho foi produzir o suco de yacon e utilizá-lo como matriz não láctea para a bactéria probiótica Bifidobacterium animalis ssp. lactis. O yacon apresentou rápido escurecimento...

  15. Assessing the effects of exposure to environmental stress on some functional properties of Bifidobacterium animalis ssp. lactis.

    Science.gov (United States)

    Amund, O D; Ouoba, L I I; Sutherland, J P; Ghoddusi, H B

    2014-12-01

    This study assessed the effects of exposing a strain of Bifidobacterium animalis ssp. lactis to acid, bile and osmotic stresses on antagonistic properties, biofilm formation and antibiotic susceptibility/resistance profile. Exposure to each stress factor appeared to have no significant effect on the antagonism against Escherichia coli NCTC 12900 and Salmonella enterica serovar Enteritidis PT4. No suppression in biofilm formation due to exposure to stress was observed. Bile and osmotic stresses resulted in significantly higher biofilm formation. Expression of an exopolysaccharide synthesis gene, gtf 01207, was significantly higher when the B. animalis ssp. lactis strain was exposed to osmotic stress. Susceptibility of the B. animalis ssp. lactis strain to chloramphenicol, erythromycin, ampicillin and vancomycin, and resistance to tetracycline remained unchanged when exposed to each stress. The expression of a tetracycline resistance gene, tet(W), was significantly higher when exposed to each stress. These results may suggest that the potential for the B. animalis ssp. lactis strain to provide probiotic benefit, after exposure to the stressful conditions of the gastrointestinal tract, remains intact.

  16. Structural basis for arabinoxylo‐oligosaccharide capture by the probiotic Bifidobacterium animalis subsp. lactis Bl‐04

    DEFF Research Database (Denmark)

    Hansen, Morten Ejby; Fredslund, Folmer; Vujicic‐Zagar, Andreja

    2013-01-01

    Glycan utilization plays a key role in modulating the composition of the gut microbiota, but molecular insight into oligosaccharide uptake by this microbial community is lacking. Arabinoxylo‐oligosaccharides (AXOS) are abundant in the diet, and are selectively fermented by probiotic bifidobacteria...... in the colon. Here we show how selectivity for AXOS uptake is established by the probiotic strain Bifidobacterium animalis subsp. lactis Bl‐04. The binding protein BlAXBP, which is associated with an ATP‐binding cassette (ABC) transporter that mediates the uptake of AXOS, displays an exceptionally broad...

  17. Assessment of stress tolerance acquisition in the heat-tolerant derivative strains of Bifidobacterium animalis subsp. lactis BB-12 and Lactobacillus rhamnosus GG.

    Science.gov (United States)

    Aakko, J; Sánchez, B; Gueimonde, M; Salminen, S

    2014-07-01

    The purpose of this study was to investigate the heat-shock response at molecular level in Lactobacillus rhamnosus GG, Bifidobacterium animalis subsp. lactis BB-12 and their heat-tolerant derivatives and to characterize the changes that make the derivatives more robust in terms of heat stress. The study strains were exposed for 2 h to a heat-shock treatment, Bif. animalis subsp. lactis BB-12 and its derivative at 50°C and the Lact. rhamnosus GG and its derivative at 60°C. Protein synthesis before and after heat shock was examined using proteomics and RT-qPCR. The analysis revealed that the regulation of seven proteins in both strain pairs was modified as a response to heat or between the original and the derivative strain. The comparison of wild-type strains and the heat-tolerant derivatives suggests that the acquisition of heat tolerance in the Bif. animalis subsp. lactis BB-12 derivative is due to a slightly increased constitutive level of chaperones, while in Lact. rhamnosus GG derivative, the main reason seems to be a higher ability to induce the production of chaperones. This study revealed possible markers of heat tolerance in B. lactis and Lact. rhamnosus strains. This study increases our knowledge on how Lactobacillus and Bifidobacterium strains may acquire heat tolerance. These findings may be useful for improving the heat tolerance of existing probiotic strains as well as screening new heat-tolerant strains. © 2014 The Society for Applied Microbiology.

  18. Safety of Bifidobacterium animalis Subsp. Lactis (B. lactis) Strain BB-12-Supplemented Yogurt in Healthy Children.

    Science.gov (United States)

    Tan, Tina P; Ba, Zhaoyong; Sanders, Mary E; D'Amico, Frank J; Roberts, Robert F; Smith, Keisha H; Merenstein, Daniel J

    2017-02-01

    Probiotics are live microorganisms that may provide health benefits to the individual when consumed in sufficient quantities. For studies conducted on health or disease endpoints on probiotics in the United States, the Food and Administration has required those studies to be conducted as investigational new drugs. This phase I, double-blinded, randomized, controlled safety study represents the first requirement of this pathway. The purpose of the study was to determine the safety of Bifidobacterium animalis subsp. lactis (B lactis) strain BB-12 (BB-12)-supplemented yogurt when consumed by a generally healthy group of children. The secondary aim was to assess the effect of BB-12-supplemented yogurt on the gut microbiota of the children. Sixty children ages 1 to 5 years were randomly assigned to consume 4 ounces of either BB-12-supplemented yogurt or nonsupplemented control yogurt daily for 10 days. The primary outcome was to assess safety and tolerability, as determined by the number of reported adverse events. A total of 186 nonserious adverse events were reported, with no significant differences between the control and BB-12 groups. No significant changes due to probiotic treatment were observed in the gut microbiota of the study cohort. BB-12-supplemented yogurt is safe and well-tolerated when consumed by healthy children. The present study will form the basis for future randomized clinical trials investigating the potential effects of BB-12-supplemented yogurt in different disease states.

  19. The extracellular proteome of Bifidobacterium animalis subsp. lactis BB‐12 reveals proteins with putative roles in probiotic effects

    DEFF Research Database (Denmark)

    Gilad, Ofir; Svensson, Birte; Viborg, Alexander Holm

    2011-01-01

    Probiotics are live microorganisms that exert health‐promoting effects on the human host, as demonstrated for numerous strains of the genus Bifidobacterium. To unravel the proteins involved in the interactions between the host and the extensively used and well‐studied probiotic strain Bifidobacte......Probiotics are live microorganisms that exert health‐promoting effects on the human host, as demonstrated for numerous strains of the genus Bifidobacterium. To unravel the proteins involved in the interactions between the host and the extensively used and well‐studied probiotic strain...... Bifidobacterium animalis subsp. lactis BB‐12, proteins secreted by the bacterium, i.e. belonging to the extracellular proteome present in the culture medium, were identified by 2‐DE coupled with MALDI‐TOF MS. Among the 74 distinct proteins identified, 31 are predicted to carry out their physiological role either...... functions include binding of plasminogen, formation of fimbriae, adhesion to collagen, attachment to mucin and intestinal cells as well as induction of immunomodulative response. These findings suggest a role of the proteins in colonization of the gastrointestinal tract, adhesion to host tissues...

  20. INHIBITION OF STAPHYLOCOCCUS AUREUS BY LACTIC ACID BACTERIA AND / OR BIFIDOBACTERIUM LACTIS DURING MILK FERMENTATION AND STORAGE

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    Khalaf S. Al-Delaimy

    2013-02-01

    Full Text Available Survival and inhibition of Staphylococcus aureus by the lactic acid bacteria (LAB starter culture (Sterptococcus thermophillus and Lactobacillus delbrukii subsp. bulgaricus and/ or probiotic bacteria Bifidobacterium lactis during milk fermentation to yoghurt and storage up to 12 days was studied. Adding S. aureus (initial count log 6.64/ ml with LAB (initial count log 6.8/ ml in milk during yoghurt processing and storage resulted in no significant change in the counts of both S. aureus and LAB during fermentation period of 4 hrs at 45° C. A steady decrease in S. aureus count during storage at 25° C and 4° C was observed reaching a complete (100 % inhibition after 9 and 12 days, respectively, with no significant increase in LAB count. Adding S. aureus (initial count log 6.62/ ml with B. lactis (initial count log 6.83/ ml in milk for 4 hr at45° C, no significant changes in the counts of both bacteria were found. After storage at 25° C and at 4° C a sharp decline in the S. aureus count with a 100 % inhibition after 6 and 9 days with approximately two log and one log increase in B. lactis counts consecutively. In general similar result was observed when adding S. aureus together with LAB and B. lactis in milk during fermentation and storage. pH values decreased during milk fermentation and storage from initially 6.55-6.64 to around 4 in most milk samples. The results of this study show that S. aureus was completely inhibited by LAB and/or B. lactis after milk fermentation to yoghurt and storage at room temperature and refrigeration for 6-9 days. It is therefore recommended to add the probiotic B. lactis with LAB to milk for yoghurt processing.

  1. Safety of Bifidobacterium animalis subsp. lactis (B. lactis) strain BB-12®-supplemented yogurt in healthy children

    Science.gov (United States)

    Tan, Tina P.; Ba, Zhaoyong; Sanders, Mary Ellen; D’Amico, Frank J.; Roberts, Robert F.; Smith, Keisha Herbin; Merenstein, Daniel J.

    2016-01-01

    Objectives Probiotics are live microorganisms that may provide health benefits to the individual when consumed in sufficient quantities. For studies conducted on health or disease endpoints on probiotics in the United States, the Food and Administration (FDA) has required those studies to be conducted as investigational new drugs. This phase I, double-blinded, randomized, controlled safety study represents the first requirement of this pathway. The purpose of the study was to determine the safety of Bifidobacterium animalis subsp. lactis (B. lactis) strain BB-12® (BB-12®)-supplemented yogurt when consumed by a generally healthy group of children. The secondary aim was to assess the effect of BB-12®-supplemented yogurt on the gut microbiota of the children. Methods Sixty children aged 1–5 years were randomly assigned to consume four ounces of either BB-12®-supplemented yogurt or non-supplemented control yogurt daily for 10 days. The primary outcome was to assess safety and tolerability, as determined by the number of reported adverse events. Results A total of 186 non-serious adverse events were reported, with no significant differences between the control and BB-12® groups. No significant changes due to probiotic treatment were observed in the gut microbiota of the study cohort. Conclusions BB-12®-supplemented yogurt is safe and well-tolerated when consumed by healthy children. This study will form the basis for future randomized clinical trials investigating the potential effects of BB-12®-supplemented yogurt in different disease states. PMID:28114246

  2. Influence of Technological Treatments on the Functionality of Bifidobacterium lactis INL1, a Breast Milk-Derived Probiotic.

    Science.gov (United States)

    Zacarías, María Florencia; Souza, Tassia Costa; Zaburlín, Natalia; Carmona Cara, Denise; Reinheimer, Jorge; Nicoli, Jacques; Vinderola, Gabriel

    2017-10-01

    The aim of this study is to evaluate the influence of the technological processing on the functionality of the human breast milk probiotic strain Bifidobacterium lactis INL1. In vitro antagonistic activity of B. lactis INL1 was detected for Gram-positive and Gram-negative pathogens. B. lactis INL1 was administered to mice as fresh (F), frozen (Z), spray-dried (S), or lyophilized (L) culture. Immune parameters (IgA, IL-10, and IFN-γ) were determined and histological analysis was performed to assess functionality and protection capacity against Salmonella. In BALB/c mice, F and S cultures induced an increase in the number of IgA-producing cells in the small intestine and IL-10 levels were increased for L culture in the large intestine. In Swiss mice, B. lactis INL1 increased secretory-IgA levels in the small intestine before and after Salmonella infection, both as F or dehydrated culture. Also, an attenuation of damage in the intestinal epithelium and less inflammatory infiltrates were observed in animals that received F and S cultures, whereas in liver only F showed some effect. The anti-inflammatory effect was confirmed in both tissues by myeloperoxidase activity and by IFN-γ levels in the intestinal content. B. lactis INL1 showed inhibitory activity against pathogens and confirmed its probiotic potential in animal models. Technological processing of the probiotic strain affected its functionality. This work provides evidence about the influence of technology on the functionality of probiotics, which may help probiotics and functional food manufacturers to take processing into consideration when assessing the functionality of new strains. © 2017 Institute of Food Technologists®.

  3. D-Tagatose production in the presence of borate by resting Lactococcus lactis cells harboring Bifidobacterium longum L-arabinose isomerase.

    Science.gov (United States)

    Salonen, Noora; Salonen, Kalle; Leisola, Matti; Nyyssölä, Antti

    2013-04-01

    Bifidobacterium longum NRRL B-41409 L-arabinose isomerase (L-AI) was overexpressed in Lactococcus lactis using a phosphate depletion inducible expression system. The resting L. lactis cells harboring the B. longum L-AI were used for production of D-tagatose from D-galactose in the presence of borate buffer. Multivariable analysis suggested that high pH, temperature and borate concentration favoured the conversion of D-galactose to D-tagatose. Almost quantitative conversion (92 %) was achieved at 20 g L⁻¹ substrate and at 37.5 °C after 5 days. The D-tagatose production rate of 185 g L⁻¹ day ⁻¹ was obtained at 300 g L⁻¹ galactose, at 1.15 M borate, and at 41 °C during 10 days when the production medium was changed every 24 h. There was no significant loss in productivity during ten sequential 24 h batches. The initial D-tagatose production rate was 290 g L⁻¹ day⁻¹ under these conditions.

  4. Spray-drying process preserves the protective capacity of a breast milk-derived Bifidobacterium lactis strain on acute and chronic colitis in mice

    Science.gov (United States)

    Burns, Patricia; Alard, Jeanne; Hrdỳ, Jiri; Boutillier, Denise; Páez, Roxana; Reinheimer, Jorge; Pot, Bruno; Vinderola, Gabriel; Grangette, Corinne

    2017-01-01

    Gut microbiota dysbiosis plays a central role in the development and perpetuation of chronic inflammation in inflammatory bowel disease (IBD) and therefore is key target for interventions with high quality and functional probiotics. The local production of stable probiotic formulations at limited cost is considered an advantage as it reduces transportation cost and time, thereby increasing the effective period at the consumer side. In the present study, we compared the anti-inflammatory capacities of the Bifidobacterium animalis subsp. lactis (B. lactis) INL1, a probiotic strain isolated in Argentina from human breast milk, with the commercial strain B. animalis subsp. lactis BB12. The impact of spray-drying, a low-cost alternative of bacterial dehydration, on the functionality of both bifidobacteria was also investigated. We showed for both bacteria that the spray-drying process did not impact on bacterial survival nor on their protective capacities against acute and chronic colitis in mice, opening future perspectives for the use of strain INL1 in populations with IBD. PMID:28233848

  5. Functional cream cheese supplemented with Bifidobacterium animalis subsp. lactis DSM 10140 and Lactobacillus reuteri DSM 20016 and prebiotics.

    Science.gov (United States)

    Speranza, Barbara; Campaniello, Daniela; Monacis, Noemi; Bevilacqua, Antonio; Sinigaglia, Milena; Corbo, Maria Rosaria

    2018-06-01

    The aim of this study was to develop a functional fresh cream cheese with Bifidobacterium animalis subsp. lactis DSM 10140 or Lactobacillus reuteri DSM 20016 and prebiotics (inulin, FOS and lactulose). The research was divided into two steps: in vitro evaluation of the effects of prebiotic compounds; validation at laboratory level with production of functional cream mini-cheeses. Prebiotics showed a protective effect: B. animalis subsp. lactis DSM 10140 cultivability on Petri dishes was positively influenced by lactulose, whereas fructooligosaccharides (FOS) were the prebiotic compounds able to prolong Lb. reuteri DSM 20016 cultivability. At 30 °C, a prolongation of the death time (more than 300 days) was observed, while the controls showed death time values about 100 days. At 45 °C, death time values increased from 32.2 (control) to 33, 35, and 38 days in the samples added with FOS, inulin and lactulose, respectively. Lactulose and FOS were chosen to be added to cream mini-cheeses inoculated with B. animalis subsp. lactis DSM 10140 and Lb. reuteri DSM 20016, respectively; the proposed functional cream cheese resulted in a product with favourable conditions for the viability of both probiotics which maintained cultivable cells above the recommended level during 28 days of storage at 4 °C with good sensory characteristics. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Microencapsulation of Bifidobacterium animalis subsp. lactis and Lactobacillus acidophilus in cocoa butter using spray chilling technology

    Science.gov (United States)

    Pedroso, D.L.; Dogenski, M.; Thomazini, M.; Heinemann, R.J.B.; Favaro-Trindade, C.S.

    2013-01-01

    In the present study, the cells of Bifidobacterium animalis subsp. lactis (BI-01) and Lactobacillus acidophilus (LAC-04) were encapsulated in cocoa butter using spray-chilling technology. Survival assays were conducted to evaluate the resistance of the probiotics to the spray-chilling process, their resistance to the simulated gastric and intestinal fluids (SGF and SIF), and their stability during 90 days of storage. The viability of the cells was not affected by microencapsulation. The free and encapsulated cells of B. animalis subsp. lactis were resistant to both SGF and SIF. The micro-encapsulated cells of L. acidophilus were more resistant to SGF and SIF than the free cells; the viability of the encapsulated cells was enhanced by 67%, while the free cells reached the detection limit of the method (103 CFU/g). The encapsulated probiotics were unstable when they were stored at 20 °C. The population of encapsulated L. acidophilus decreased drastically when they were stored at 7 °C; only 20% of cells were viable after 90 days of storage. The percentage of viable cells of the encapsulated B. animalis subsp.lactis, however, was 72% after the same period of storage. Promising results were obtained when the microparticles were stored at −18 °C; the freeze granted 90 days of shelf life to the encapsulated cells. These results suggest that the spray-chilling process using cocoa butter as carrier protects L. acidophilus from gastrointestinal fluids. However, the viability of the cells during storage must be improved. PMID:24516445

  7. Microencapsulation of Bifidobacterium animalis subsp. lactis and Lactobacillus acidophilus in cocoa butter using spray chilling technology

    Directory of Open Access Journals (Sweden)

    D.L. Pedroso

    2013-09-01

    Full Text Available In the present study, the cells of Bifidobacterium animalis subsp. lactis (BI-01 and Lactobacillus acidophilus (LAC-04 were encapsulated in cocoa butter using spray-chilling technology. Survival assays were conducted to evaluate the resistance of the probiotics to the spray-chilling process, their resistance to the simulated gastric and intestinal fluids (SGF and SIF, and their stability during 90 days of storage. The viability of the cells was not affected by microencapsulation. The free and encapsulated cells of B. animalis subsp. lactis were resistant to both SGF and SIF. The micro-encapsulated cells of L. acidophilus were more resistant to SGF and SIF than the free cells; the viability of the encapsulated cells was enhanced by 67%, while the free cells reached the detection limit of the method (10³ CFU/g. The encapsulated probiotics were unstable when they were stored at 20 °C. The population of encapsulated L. acidophilus decreased drastically when they were stored at 7 °C; only 20% of cells were viable after 90 days of storage. The percentage of viable cells of the encapsulated B. animalis subsp.lactis, however, was 72% after the same period of storage. Promising results were obtained when the microparticles were stored at -18 °C; the freeze granted 90 days of shelf life to the encapsulated cells. These results suggest that the spray-chilling process using cocoa butter as carrier protects L. acidophilus from gastrointestinal fluids. However, the viability of the cells during storage must be improved.

  8. Effect of yoghurt containing Bifidobacterium lactis Bb12® on faecal excretion of secretory immunoglobulin A and human beta-defensin 2 in healthy adult volunteers

    Directory of Open Access Journals (Sweden)

    Kabeerdoss Jayakanthan

    2011-12-01

    Full Text Available Abstract Background Probiotics are used to provide health benefits. The present study tested the effect of a probiotic yoghurt on faecal output of beta-defensin and immunoglobulin A in a group of young healthy women eating a defined diet. Findings 26 women aged 18-21 (median 19 years residing in a hostel were given 200 ml normal yoghurt every day for a week, followed by probiotic yoghurt containing Bifidobacterium lactis Bb12® (109 in 200 ml for three weeks, followed again by normal yoghurt for four weeks. Stool samples were collected at 0, 4 and 8 weeks and assayed for immunoglobulin A and human beta-defensin-2 by ELISA. All participants tolerated both normal and probiotic yoghurt well. Human beta-defensin-2 levels in faeces were not altered during the course of the study. On the other hand, compared to the basal sample, faecal IgA increased during probiotic feeding (P = 0.0184 and returned to normal after cessation of probiotic yoghurt intake. Conclusions Bifidobacterium lactis Bb12® increased secretory IgA output in faeces. This property may explain the ability of probiotics to prevent gastrointestinal and lower respiratory tract infections.

  9. Gene Replacement and Fluorescent Labeling to Study the Functional Role of Exopolysaccharides in Bifidobacterium animalis subsp. lactis

    Directory of Open Access Journals (Sweden)

    Nuria Castro-Bravo

    2017-07-01

    Full Text Available An extracellular layer of exopolysaccharides (EPS covers the surface of some Bifidobacterium animalis subsp. lactis strains, which could be of relevance for its probiotic performance. In order to understand the functional characteristics of B. animalis subsp. lactis, two isogenic strains that differ in their EPS-producing phenotype, due to a single mutation in the gene Balat_1410, were studied. By means of a double crossover recombination strategy, successfully used for the first time in bifidobacteria, Balat_1410 in the type strain B. animalis subsp. lactis DSM10140 was replaced by a mutated gene containing a non-synonymous mutation previously associated with the appearance of a mucoid-ropy phenotype. Nuclear magnetic resonance and SEC-MALS analyses showed that the novel strain harboring the mutation acquired a ropy phenotype, due to the production of a high molecular weight (HMW-EPS that is not produced in the wild-type strain. Fluorescence labeling of both strains with two fluorescent proteins, m-Cherry and Green Fluorescent Protein, was achieved by expressing the corresponding genes under the control of a native selected promoter (the elongation factor Tu promoter. Remarkably, qualitative and quantitative fluorescence analyses demonstrated that the ropy strain displays a lower capability to adhere to human intestinal epithelial cells. In addition, the presence of the HMW-EPS reduced the capability of the producing strain to form biofilms upon three different abiotic surfaces. This work also highlights the fact that different EPS confer variable functional characteristics to the bifidobacterial surface, which may be relevant for the performance of B. animalis subsp. lactis as a probiotic. The construction of molecular tools allowing the functional characterization of surface structures in next generation probiotics is still a challenging issue that deserves further attention, given the relevant role that such molecules must play in the

  10. Bifidobacterium animalis ssp. lactis CNCM-I2494 Restores Gut Barrier Permeability in Chronically Low-Grade Inflamed Mice.

    Science.gov (United States)

    Martín, Rebeca; Laval, Laure; Chain, Florian; Miquel, Sylvie; Natividad, Jane; Cherbuy, Claire; Sokol, Harry; Verdu, Elena F; van Hylckama Vlieg, Johan; Bermudez-Humaran, Luis G; Smokvina, Tamara; Langella, Philippe

    2016-01-01

    Growing evidence supports the efficacy of many probiotic strains in the management of gastrointestinal disorders associated with deregulated intestinal barrier function and/or structure. In particular, bifidobacteria have been studied for their efficacy to both prevent and treat a broad spectrum of animal and/or human gut disorders. The aim of the current work was thus to evaluate effects on intestinal barrier function of Bifidobacterium animalis ssp. lactis CNCM-I2494, a strain used in fermented dairy products. A chronic dinitrobenzene sulfonic acid (DNBS)-induced low-grade inflammation model causing gut dysfunction in mice was used in order to study markers of inflammation, intestinal permeability, and immune function in the presence of the bacterial strain. In this chronic low-grade inflammation mice model several parameters pointed out the absence of an over active inflammation process. However, gut permeability, lymphocyte populations, and colonic cytokines were found to be altered. B. animalis ssp. lactis CNCM-I2494 was able to protect barrier functions by restoring intestinal permeability, colonic goblet cell populations, and cytokine levels. Furthermore, tight junction (TJ) proteins levels were also measured by qRT-PCR showing the ability of this strain to specifically normalize the level of several TJ proteins, in particular for claudin-4. Finally, B. lactis strain counterbalanced CD4(+) lymphocyte alterations in both spleen and mesenteric lymphoid nodes. It restores the Th1/Th2 ratio altered by the DNBS challenge (which locally augments CD4(+) Th1 cells) by increasing the Th2 response as measured by the increase in the production of major representative Th2 cytokines (IL-4, IL-5, and IL-10). Altogether, these data suggest that B. animalis ssp. lactis CNCM-I2494 may efficiently prevent disorders associated with increased barrier permeability.

  11. Safety of Bifidobacterium animalis subsp. lactis (B. lactis) strain BB-12-supplemented yogurt in healthy adults on antibiotics: a phase I safety study.

    Science.gov (United States)

    Merenstein, Daniel J; Tan, Tina P; Molokin, Aleksey; Smith, Keisha Herbin; Roberts, Robert F; Shara, Nawar M; Mete, Mihriye; Sanders, Mary Ellen; Solano-Aguilar, Gloria

    2015-01-01

    Probiotics are live microorganisms that, when administered in sufficient doses, provide health benefits on the host. The United States Food and Drug Administration (FDA) requires phase I safety studies for probiotics when the intended use of the product is as a drug. The purpose of the study was to determine the safety of Bifidobacterium animalis subsp lactis (B. lactis) strain BB-12 (BB-12)-supplemented yogurt when consumed by a generally healthy group of adults who were prescribed a 10-day course of antibiotics for a respiratory infection. Secondary aims were to assess the ability of BB-12 to affect the expression of whole blood immune markers associated with cell activation and inflammatory response. A phase I, double-blinded, randomized controlled study was conducted in compliance with FDA guidelines for an Investigational New Drug (IND). Forty participants were randomly assigned to consume 4 ounces of either BB-12 -supplemented yogurt or non-supplemented control yogurt daily for 10 d. The primary outcome was to assess safety and tolerability, assessed by the number of reported adverse events. A total of 165 non-serious adverse events were reported, with no differences between the control and BB-12 groups. When compared to the control group, B lactis fecal levels were modestly higher in the BB-12-supplemented group. In a small subset of patients, changes in whole blood expression of genes associated with regulation and activation of immune cells were detected in the BB-12-supplemented group. BB-12-supplemented yogurt is safe and well tolerated when consumed by healthy adults concurrently taking antibiotics. This study will form the basis for future randomized clinical trials investigating the potential immunomodulatory effects of BB-12-supplemented yogurt in a variety of disease states.

  12. Predominant genera of fecal microbiota in children with atopic dermatitis are not altered by intake of probiotic bacteria Lactobacillus acidophilus NCFM and Bifidobacterium animalis subsp.lactis Bi-07

    DEFF Research Database (Denmark)

    Larsen, Nadejda Nikolajevna; Vogensen, Finn Kvist; Gøbel, Rikke Juul

    2011-01-01

    randomized to intake of one of the probiotic strain or placebo. Microbial composition was characterized by denaturing gradient gel electrophoresis, quantitative PCR and, in a subset of subjects, by pyrosequencing of the 16S rRNA gene. The core population of the Lactobacillus group was identified...... significantly after intervention, indicating survival of the ingested bacteria. The levels of Bifidobacterium correlated positively (P = 0.03), while the levels of the Lactobacillus group negatively (P = 0.01) with improvement of atopic eczema evaluated by the Severity Scoring of Atopic Dermatitis index......The effect of probiotic bacteria Lactobacillus acidophilus NCFM and Bifidobacterium lactis Bi-07 on the composition of the Lactobacillus group, Bifidobacterium and the total bacterial population in feces from young children with atopic dermatitis was investigated. The study included 50 children...

  13. Consumption of Dairy Yogurt Containing Lactobacillus paracasei ssp. paracasei, Bifidobacterium animalis ssp. lactis and Heat-Treated Lactobacillus plantarum Improves Immune Function Including Natural Killer Cell Activity

    Science.gov (United States)

    Lee, Ayoung; Lee, Young Ju; Yoo, Hye Jin; Kim, Minkyung; Chang, Yeeun; Lee, Dong Seog; Lee, Jong Ho

    2017-01-01

    The aim of this study was to investigate the impact of consuming dairy yogurt containing Lactobacillus paracasei ssp. paracasei (L. paracasei), Bifidobacterium animalis ssp. lactis (B. lactis) and heat-treated Lactobacillus plantarum (L. plantarum) on immune function. A randomized, open-label, placebo-controlled study was conducted on 200 nondiabetic subjects. Over a twelve-week period, the test group consumed dairy yogurt containing probiotics each day, whereas the placebo group consumed milk. Natural killer (NK) cell activity, interleukin (IL)-12 and immunoglobulin (Ig) G1 levels were significantly increased in the test group at twelve weeks compared to baseline. Additionally, the test group had significantly greater increases in serum NK cell activity and interferon (IFN)-γ and IgG1 than placebo group. Daily consumption of dairy yogurt containing L. paracasei, B. lactis and heat-treated L. plantarum could be an effective option to improve immune function by enhancing NK cell function and IFN-γ concentration (ClinicalTrials.gov: NCT03051425). PMID:28561762

  14. Consumption of Dairy Yogurt Containing Lactobacillus paracasei ssp. paracasei, Bifidobacterium animalis ssp. lactis and Heat-Treated Lactobacillus plantarum Improves Immune Function Including Natural Killer Cell Activity

    Directory of Open Access Journals (Sweden)

    Ayoung Lee

    2017-05-01

    Full Text Available The aim of this study was to investigate the impact of consuming dairy yogurt containing Lactobacillus paracasei ssp. paracasei (L. paracasei, Bifidobacterium animalis ssp. lactis (B. lactis and heat-treated Lactobacillus plantarum (L. plantarum on immune function. A randomized, open-label, placebo-controlled study was conducted on 200 nondiabetic subjects. Over a twelve-week period, the test group consumed dairy yogurt containing probiotics each day, whereas the placebo group consumed milk. Natural killer (NK cell activity, interleukin (IL-12 and immunoglobulin (Ig G1 levels were significantly increased in the test group at twelve weeks compared to baseline. Additionally, the test group had significantly greater increases in serum NK cell activity and interferon (IFN-γ and IgG1 than placebo group. Daily consumption of dairy yogurt containing L. paracasei, B. lactis and heat-treated L. plantarum could be an effective option to improve immune function by enhancing NK cell function and IFN-γ concentration (ClinicalTrials.gov: NCT03051425.

  15. Consumption of Dairy Yogurt Containing Lactobacillus paracasei ssp. paracasei, Bifidobacterium animalis ssp. lactis and Heat-Treated Lactobacillus plantarum Improves Immune Function Including Natural Killer Cell Activity.

    Science.gov (United States)

    Lee, Ayoung; Lee, Young Ju; Yoo, Hye Jin; Kim, Minkyung; Chang, Yeeun; Lee, Dong Seog; Lee, Jong Ho

    2017-05-31

    The aim of this study was to investigate the impact of consuming dairy yogurt containing Lactobacillus paracasei ssp. paracasei ( L. paracasei ), Bifidobacterium animalis ssp. lactis ( B. lactis ) and heat-treated Lactobacillus plantarum ( L. plantarum ) on immune function. A randomized, open-label, placebo-controlled study was conducted on 200 nondiabetic subjects. Over a twelve-week period, the test group consumed dairy yogurt containing probiotics each day, whereas the placebo group consumed milk. Natural killer (NK) cell activity, interleukin (IL)-12 and immunoglobulin (Ig) G1 levels were significantly increased in the test group at twelve weeks compared to baseline. Additionally, the test group had significantly greater increases in serum NK cell activity and interferon (IFN)-γ and IgG1 than placebo group. Daily consumption of dairy yogurt containing L. paracasei , B. lactis and heat-treated L. plantarum could be an effective option to improve immune function by enhancing NK cell function and IFN-γ concentration (ClinicalTrials.gov: NCT03051425).

  16. Discovery of proteins involved in the interaction between prebiotics carbohydrates and probiotics & whole proteome analysis of the probiotic strain Bifidobacterium animalis susp. lactis BB-12

    DEFF Research Database (Denmark)

    Gilad, Ofir

    Probiotic bacteria, which primarily belong to the genera Lactobascillus and Bifidobacterium, are live microorganisms that have been related to a variety of health-promoting effects. Prebiotics are indigestible food components that specifically stimulate the growth of probiotic organisms...... in the human gastrointestinal tract. Despite an increased scientific focus within this field, the mechanisms behind the beneficial effects exerted by pre- and probiotics are still far from fully understood. The purpose of the present industrial-PhD project was to identify proteins involved in interactions...... between the widely-used, extensively-studied probiotic strain Bifidobacterium animalis subsp. lactis BB-12 and potentially-prebiotic carbohydrates. The project was initiated with a screening phase in which more than 40 carbohydrates were tested for their ability to promote the growth of the bacterium...

  17. The effects of Bifidobacterium animalis ssp. lactis B94 on gastrointestinal wellness in adults with Prader-Willi syndrome: study protocol for a randomized controlled trial.

    Science.gov (United States)

    Alyousif, Zainab; Miller, Jennifer L; Sandoval, Mariana Y; MacPherson, Chad W; Nagulesapillai, Varuni; Dahl, Wendy J

    2018-04-27

    Constipation is a frequent problem in adults with Prader-Willi syndrome. Certain probiotics have been shown to improve transit and gastrointestinal symptoms of adults with functional constipation. The aim of this study is to determine the effect of daily consumption of Bifidobacterium animalis ssp. lactis B94 (B. lactis B94) on stool frequency, stool form, and gastrointestinal symptoms in adults with Prader-Willi syndrome. Adults with Prader-Willi syndrome (18-75 years old, n = 36) will be recruited and enrolled in a 20-week, randomized, double-blind, placebo-controlled, crossover study. Study subjects will be randomized to B. lactis B94 or placebo each for a 4-week period, preceded by a 4-week baseline and followed by 4-week washouts. Subjects will complete daily records of stool frequency and stool form (a proxy of transit time). Dietary intake data also will be collected. Stools, one in each period, will be collected for exploratory microbiota analyses. To our knowledge, this is the first randomized controlled trial evaluating the effectiveness of B. lactis in adults with Prader-Willi syndrome. The results of this study will provide evidence of efficacy for future clinical trials in patient populations with constipation. ClinicalTrials.gov ( NCT03277157 ). Registered on 08 September 2017.

  18. Production of beta-glucosidase and hydrolysis of isoflavone phytoestrogens by Lactobacillus acidophilus, Bifidobacterium lactis, and Lactobacillus casei in soymilk.

    Science.gov (United States)

    Donkor, O N; Shah, N P

    2008-01-01

    The study determined beta-glucosidase activity of commercial probiotic organisms for hydrolysis of isoflavone to aglycones in fermenting soymilk. Soymilk made with soy protein isolate (SPI) was fermented with Lactobacillus acidophilus LAFTI L10, Bifidobacterium lactis LAFTI B94, and Lactobacillus casei LAFTI L26 at 37 degrees C for 48 h and the fermented soymilk was stored for 28 d at 4 degrees C. beta-Glucosidase activity of organisms was determined using rho-nitrophenyl beta-D-glucopyranoside as a substrate and the hydrolysis of isoflavone glycosides to aglycones by these organisms was carried out. The highest level of growth occurred at 12 h for L. casei L26, 24 h for B. lactis B94, and 36 h for L. acidophilus L10 during fermentation in soymilk. Survival after storage at 4 degrees C for 28 d was 20%, 15%, and 11% greater (P < 0.05) than initial cell counts, respectively. All the bacteria produced beta-glucosidase, which hydrolyzed isoflavone beta-glycosides to isoflavone aglycones. The decrease in the concentration of beta-glycosides and the increase in the concentration of aglycones were significant (P < 0.05) in the fermented soymilk. Increased isoflavone aglycone content in fermented soymilk is likely to improve the biological functionality of soymilk.

  19. Influence of the addition of Lactobacillus acidophilus La-05, Bifidobacterium animalis subsp. lactis Bb-12 and inulin on the technological, physicochemical, microbiological and sensory features of creamy goat cheese.

    Science.gov (United States)

    Barbosa, Ilsa C; Oliveira, Maria E G; Madruga, Marta S; Gullón, Beatriz; Pacheco, Maria T B; Gomes, Ana M P; Batista, Ana S M; Pintado, Maria M E; Souza, Evandro L; Queiroga, Rita C R E

    2016-10-12

    The effects of the addition of Lactobacillus acidophilus LA-05, Bifidobacterium animalis subsp. lactis BB-12 and inulin on the quality characteristics of creamy goat cheese during refrigerated storage were evaluated. The manufactured cheeses included the addition of starter culture (Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris - R-704) (CC); starter culture, L. acidophilus LA-05 and inulin (CLA); starter culture, B. lactis BB-12 and inulin (CBB); or starter culture, L. acidophilus LA-05, B. lactis BB-12 and inulin (CLB). In the synbiotic cheeses (CLA, CBB and CLB), the counts of L. acidophilus LA-05 and B. lactis BB-12 were greater than 6log CFU g -1 , the amount of inulin was greater than 6 g per 100 g, and the firmness was reduced. The cheeses evaluated had high brightness values (L*), with a predominance of yellow (b*). CC had higher contents of proteins, lipids and minerals compared to the other cheeses. There was a decrease in the amount of short-chain fatty acids (SCFAs) and an increase of medium-chain (MCFAs) and long-chain fatty acids (LCFAs) in the synbiotic cheeses compared to CC. The amount of conjugated linoleic acid increased in CLA, CBB and CLB. The highest depth of proteolysis and the greatest changes in the release of free amino acids were found in CLB. The addition of inulin and probiotics, alone or in co-culture, did not affect the cheese acceptance. Inulin and probiotics can be used together for the production of creamy goat cheese without negatively affecting the general quality characteristics of the product, and to add value because of its synbiotic potential.

  20. Macrolide Resistance Mediated by a Bifidobacterium breve Membrane Protein

    OpenAIRE

    Margolles, Abelardo; Moreno, José Antonio; van Sinderen, Douwe; de los Reyes-Gavilán, Clara G.

    2005-01-01

    A gene coding for a hypothetical membrane protein from Bifidobacterium breve was expressed in Lactococcus lactis. Immunoblotting demonstrated that this protein is located in the membrane. Phenotypical changes in sensitivity towards 21 antibiotics were determined. The membrane protein-expressing cells showed higher levels of resistance to several macrolides.

  1. Probiotic Lactobacillus acidophilus NCFM and Bifidobacterium animalis subsp lactis Bl-04 interactions with prebiotic carbohydrates using differential proteomics and protein characterization

    DEFF Research Database (Denmark)

    Hansen, Morten Ejby

    of probiotics, primarily non-digestible carbohydrates, are termed prebiotics. The knowledge of prebiotic utilization and in particular the specificities of carbohydrate transport and metabolism are limited, hampering robust understanding for the basis of selective utilization of known prebiotics...... and the discovery and documentation of novel ones. In this project we set out to investigate the metabolism of carbohydrates that are prebiotic or potential prebiotic compounds utilized by the probiotic organisms Lactobacillus acidophilus NCFM (NCFM) and Bifidobacterium animalis subsp. lactis BL-04 (Bl-04). The aim...... of this Ph.D. thesis was the study of probiotic NCFM and Bl-04 interaction with prebiotic carbohydrates using differential proteomics and protein characterization. Proteomics is a potential omics tool to investigate probiotic bacteria and its response to prebiotic carbohydrates at the protein level...

  2. Study on effect of Artemisia sieberi hydro-alcoholic extract on the survival of Lactobacillus acidophilus and Bifidobacterium lactis in probiotic yoghurt

    Directory of Open Access Journals (Sweden)

    Saeed Akbari

    2017-05-01

    Full Text Available Background and Aim: In the present study, the possibility of probiotic yoghurt production using Artemisia sieberi hydro- alcoholic extract and also the effects of different concentrations of this medicinal herb on the survival of two probiotic strains, Lactobacillus acidophilus and Bifidobacterium lactis, in probiotic yoghurt were investigated. Materials and Methods: In different treatments, the amounts of 0, 0.1, 0.2, 0.3 and 0.4 gr/lit of Artemisia sieberi extract together with conventional yoghurt starter, Bif. lactis and lact. acidophilus were added to 1 liter of boiled milk. The samples were incubated at 37˚centigrade, and then, the acidity and pH changes every two hours during the incubation period were examined up to approximately 80˚ of the survival of probiotic bacteria was tested during the storage of the samples in the refrigerator. On the tenth day, after yoghurt production, all the samples were examined for sensory evaluation using a panel test and the obtained data was analyzed by means of SPSS software (V:19. Results: There was no significant difference in the acidity and pH changes during the production process of probiotic yoghurt in different treatments. The probiotic yoghurt containing 0.4 gr/lit  of Artemisia hydro-alcoholic extract had the best quality in terms of organoleptic properties and shelf life of the product. During 21 days storage in the refrigerator none of the treatments showed the number of probiotic bacteria less than 106 bacteria in gram. Conclusion: It was found that appropriate concentrations of Artemisia sieberi extract can be used for the production of probiotic yoghurt, as a new functional food containing Lactobacillus acidophilus and Bifodobacterium lactis.

  3. Probiotic Yogurt Culture Bifidobacterium Animalis Subsp. Lactis BB-12 and Lactobacillus Acidophilus LA-5 Modulate the Cytokine Secretion by Peripheral Blood Mononuclear Cells from Patients with Ulcerative Colitis.

    Science.gov (United States)

    Sheikhi, A; Shakerian, M; Giti, H; Baghaeifar, M; Jafarzadeh, A; Ghaed, V; Heibor, M R; Baharifar, N; Dadafarin, Z; Bashirpour, G

    2016-06-01

    There are some evidences for the immunomodulation disorders in the response to intestinal microbiota in inflammatory bowel disease. Yogurt is a fermented milk product made with a starter culture consisting of different probiotics which could be colonized in intestine. However, the role of probiotics in the aetiopathogenesis of ulcerative colitis (UC) has not been clarified. To determine how the immune system responds to these bacteria this study was planned. Bifidobacterium lactis BB-12 (B. lactis) and Lactobacillus acidophilus LA-5 (L. acidophilus) were cultivated on MRS broth. PBMCs of 36 UC patients were separated by Ficoll-Hypaque centrifugation and co-cultured with different concentrations of UV killed bacteria in RPMI-1 640 plus 10% FCS for 48/72 h. IL-10, TGF-β, IFN-γ and TNF-α were measured in supernatant of PBMCs by ELISA. Both bacteria significantly augmented IL-10, TGF-β, IFN-γ and TNF-α compared to control (p<0.001). The secretion levels of IL-10 and TGF-β by B. lactis- compared to L. acidophilus-stimulated PBMCs were significantly higher (p<0.05, p<0.01 respectively). The secretion levels of TNF-α and IFN-γ by PBMCs after 72 h were significantly lower compared to 48 h stimulation by B. lactis (p<0.001, p<0.035 respectively). These data show that both probiotics may trigger the pro- and anti-inflammatory immune response of UC patients. It seems that IL-10/TGF-β uprising by B. lactis could be the reason of TNF-α/IFN-γ reduction. Therefore albeit B. lactis still stimulates the effector Th cells but because of more stimulatory effect on Tregs, it could be a good potential therapeutic candidate for further investigation. © Georg Thieme Verlag KG Stuttgart · New York.

  4. Effects of synbiotic fermented milk containing Lactobacillus acidophilus La-5 and Bifidobacterium animalis ssp. lactis BB-12 on the fecal microbiota of adults with irritable bowel syndrome: A randomized double-blind, placebo-controlled trial.

    Science.gov (United States)

    Bogovič Matijašić, Bojana; Obermajer, Tanja; Lipoglavšek, Luka; Sernel, Tjaša; Locatelli, Igor; Kos, Mitja; Šmid, Alenka; Rogelj, Irena

    2016-07-01

    We conducted a randomized double-blind, placebo-controlled multicentric study to investigate the influence of a synbiotic fermented milk on the fecal microbiota composition of 30 adults with irritable bowel syndrome (IBS). The synbiotic product contained Lactobacillus acidophilus La-5, Bifidobacterium animalis ssp. lactis BB-12, Streptococcus thermophilus, and dietary fiber (90% inulin, 10% oligofructose), and a heat-treated fermented milk without probiotic bacteria or dietary fiber served as placebo. Stool samples were collected after a run-in period, a 4-wk consumption period, and a 1-wk follow-up period, and were subjected to real-time PCR and 16S rDNA profiling by next-generation sequencing. After 4wk of synbiotic (11 subjects) or placebo (19 subjects) consumption, a greater increase in DNA specific for L. acidophilus La-5 and Bifidobacterium animalis ssp. lactis was detected in the feces of the synbiotic group compared with the placebo group by quantitative real-time PCR. After 1wk of follow-up, the content of L. acidophilus La-5 and B. animalis ssp. lactis decreased to levels close to initial levels. No significant changes with time or differences between the groups were observed for Lactobacillus, Enterobacteriaceae, Bifidobacterium, or all bacteria. The presence of viable BB-12- and La-5-like bacteria in the feces resulting from the intake of synbiotic product was confirmed by random amplification of polymorphic DNA (RAPD)-PCR. At the end of consumption period, the feces of all subjects assigned to the synbiotic group contained viable bacteria with a BB-12-like RAPD profile, and after 1wk of follow-up, BB-12-like bacteria remained in the feces of 87.5% of these subjects. The presence of La-5-like colonies was observed less frequently (37.5 and 25% of subjects, respectively). Next-generation sequencing of 16S rDNA amplicons revealed that only the percentage of sequences assigned to Strep. thermophilus was temporarily increased in both groups, whereas the

  5. Survival of Lactobacillus acidophilus NCFM® and Bifidobacterium lactis HN019 encapsulated in chocolate during in vitro simulated passage of the upper gastrointestinal tract

    DEFF Research Database (Denmark)

    Klindt-Toldam, Stine; Larsen, Susanne K.; Saaby, Lasse

    2016-01-01

    Probiotic microorganisms are exposed to different types of stress both before and after consumption which strongly influences probiotic survival. Here the viability of 2 different probiotic bacteria incorporated in different types of chocolate was investigated during storage and passage of the up......Probiotic microorganisms are exposed to different types of stress both before and after consumption which strongly influences probiotic survival. Here the viability of 2 different probiotic bacteria incorporated in different types of chocolate was investigated during storage and passage...... of the upper gastro-intestinal tract using both a static and a dynamic gastric in vitro model. Lactobacillus acidophilus NCFM® and Bifidobacterium lactis HN019 equalling a total concentration of 2 × 108, 2 × 109 and 2 × 1010 CFU/g chocolate were added to samples of milk chocolate, 57% and 72% dark chocolate...... dairy and juice based probiotic products, chocolate was an excellent carrier for probiotic delivery, because of very good survival of probiotics during simulated passage of the upper GI tract. The viability of B. lactis was slightly higher than Lb. acidophilus and survival rates were >6.5 log CFU...

  6. ELABORACIÓN DE QUESITO ANTIOQUEÑO REDUCIDO EN SODIO Y ADICIONADO CON Bifidobacterium lactis

    Directory of Open Access Journals (Sweden)

    EDINSON ELIÉCER BEJARANO TORO

    2017-06-01

    Full Text Available The quesito antioqueño (QA, fresh, soft, milled and salty cheese, without added bacteria. This cheese contains 2,1% of sodium chloride. Were supplemented with Bifidobacterium lactis (bb12 and It was salty with NaCl (Q1 and some mixtures of NaCl/KCl (3:1 (Q2 and 1:1 (Q3, w/w, to reduce the sodium content and give probiotic characteristics. There were no significant differences between treatments (Q1, Q2 and Q3 (P>0,05 in some compositional (moisture, MG/MS, total protein, ash, acidity, chemical (pH and physical (hardness, adhesiveness, springiness, cohesiveness, gumminess, chewiness, resilience characteristics. A significant difference was observed by storage time in moisture, pH, protein content and acidity (P<0,05. With respect to Na and K content, there was a significant differences between treatments (P<0,05 but was not in the Ca content. In Q2 the Na level was decreased 24,2% and K increased 143% in average; in Q3 the Na level was decreased 48,3% and K increased 311%. The processed QA with 50% of Na substitution maintains the traditional compositional a physicochemical characteristics, therefore, according to this investigation results, can be performed this substitution and it is an excellent matrix to include probiotics in the people diet.

  7. The Impact of Storage Conditions on the Stability of Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp. lactis Bb12 in Human Milk.

    Science.gov (United States)

    Mantziari, Anastasia; Aakko, Juhani; Kumar, Himanshu; Tölkkö, Satu; du Toit, Elloise; Salminen, Seppo; Isolauri, Erika; Rautava, Samuli

    2017-11-01

    Human milk is the optimal source of complete nutrition for neonates and it also guides the development of infant gut microbiota. Importantly, human milk can be supplemented with probiotics to complement the health benefits of breastfeeding. Storage of human milk for limited periods of time is often unavoidable, but little is known about the effect of different storage conditions (temperature) on the viability of the added probiotics. Therefore, in this study, we evaluated how different storage conditions affect the viability of two specific widely used probiotics, Lactobacillus rhamnosus GG (LGG) and Bifidobacterium animalis subsp. lactis (Bb12), in human milk by culturing and quantitative polymerase chain reaction. Our results indicate that LGG and Bb12 remained stable throughout the storage period. Thus, we conclude that human milk offers an appropriate matrix for probiotic supplementation.

  8. Bifidobacterium lactis B94 plus inulin for Treatment of Helicobacter pylori infection in children: does it increase eradication rate and patient compliance?

    Science.gov (United States)

    Islek, A; Sayar, E; Yilmaz, A; Artan, R

    2015-01-01

    The aim of this study is to investigate the effects of Bifidobacterium lactis B94 and inulin (synbiotic) treatment on eradication rate and patient compliance in subjects treated for symptomatic H. pylori infection. Patients with symptomatic H. pylori infection were divided into two groups. One group was treated with standard triple therapy (lansoprazole, amoxicillin, and clarithromycin) and B. lactis B94 (5 × 109 CFU/dose) plus inulin (900 mg) twice daily for seven days. The control group was treated with standard triple therapy and placebo. The side effects and eradication rates were evaluated at the end of the study. Ninety-three patients with H. pylori infection were treated with either synbiotic plus triple therapy (n = 47) or placebo plus triple therapy (n = 46). The infection eradication rates were not significantly different between the synbiotic and placebo groups [intent-to-treat (ITT), 80.8% and 67.3%, p = 0.13, respectively; per-protocol (PP), 86.3% and 81.5%, p = 0.55, respectively]. The drug side effects were significantly higher in the placebo group than in the synbiotic group (63% and 17%, respectively, p < 0.01). Although no intolerable adverse side effects were observed in the synbiotic group, intolerable adverse side effects were observed in 13% of the placebo group (p = 0.01). Our results suggest that twice daily 5 × 109 CFU/dose B. lactis B94 plus 900 mg inulin treatment did not have a direct positive effect on the H. pylori eradication rate. However, this treatment had significantly reduced side effects and indirectly increased eradication rates by increasing patient compliance. © Acta Gastro-Enterologica Belgica.

  9. Development of a rapid SNP-typing assay to differentiate Bifidobacterium animalis ssp. lactis strains used in probiotic-supplemented dairy products.

    Science.gov (United States)

    Lomonaco, Sara; Furumoto, Emily J; Loquasto, Joseph R; Morra, Patrizia; Grassi, Ausilia; Roberts, Robert F

    2015-02-01

    Identification at the genus, species, and strain levels is desirable when a probiotic microorganism is added to foods. Strains of Bifidobacterium animalis ssp. lactis (BAL) are commonly used worldwide in dairy products supplemented with probiotic strains. However, strain discrimination is difficult because of the high degree of genome identity (99.975%) between different genomes of this subspecies. Typing of monomorphic species can be carried out efficiently by targeting informative single nucleotide polymorphisms (SNP). Findings from a previous study analyzing both reference and commercial strains of BAL identified SNP that could be used to discriminate common strains into 8 groups. This paper describes development of a minisequencing assay based on the primer extension reaction (PER) targeting multiple SNP that can allow strain differentiation of BAL. Based on previous data, 6 informative SNP were selected for further testing, and a multiplex preliminary PCR was optimized to amplify the DNA regions containing the selected SNP. Extension primers (EP) annealing immediately adjacent to the selected SNP were developed and tested in simplex and multiplex PER to evaluate their performance. Twenty-five strains belonging to 9 distinct genomic clusters of B. animalis ssp. lactis were selected and analyzed using the developed minisequencing assay, simultaneously targeting the 6 selected SNP. Fragment analysis was subsequently carried out in duplicate and demonstrated that the assay yielded 8 specific profiles separating the most commonly used commercial strains. This novel multiplex PER approach provides a simple, rapid, flexible SNP-based subtyping method for proper characterization and identification of commercial probiotic strains of BAL from fermented dairy products. To assess the usefulness of this method, DNA was extracted from yogurt manufactured with and without the addition of B. animalis ssp. lactis BB-12. Extracted DNA was then subjected to the minisequencing

  10. Biochemical and kinetic characterisation of a novel xylooligosaccharide-upregulated GH43 β-d-xylosidase/α-l-arabinofuranosidase (BXA43) from the probiotic Bifidobacterium animalis subsp. lactis BB-12

    DEFF Research Database (Denmark)

    Viborg, Alexander Holm; Sørensen, Kim Ib; Gilad, Ofir

    2013-01-01

    The Bifidobacterium animalis subsp. lactis BB-12 gene BIF_00092, assigned to encode a β-d-xylosidase (BXA43) of glycoside hydrolase family 43 (GH43), was cloned with a C-terminal His-tag and expressed in Escherichia coli. BXA43 was purified to homogeneity from the cell lysate and found to be a dual......-specificity exo-hydrolase active on para-nitrophenyl-β-d-xylopyranoside (pNPX), para-nitrophenyl-α-L-arabinofuranoside (pNPA), β-(1 → 4)-xylopyranosyl oligomers (XOS) of degree of polymerisation (DP) 2–4, and birchwood xylan. A phylogenetic tree of the 92 characterised GH43 enzymes displayed five distinct groups...

  11. Immune Modulating Capability of Two Exopolysaccharide-Producing Bifidobacterium Strains in a Wistar Rat Model

    Directory of Open Access Journals (Sweden)

    Nuria Salazar

    2014-01-01

    Full Text Available Fermented dairy products are the usual carriers for the delivery of probiotics to humans, Bifidobacterium and Lactobacillus being the most frequently used bacteria. In this work, the strains Bifidobacterium animalis subsp. lactis IPLA R1 and Bifidobacterium longum IPLA E44 were tested for their capability to modulate immune response and the insulin-dependent glucose homeostasis using male Wistar rats fed with a standard diet. Three intervention groups were fed daily for 24 days with 10% skimmed milk, or with 109 cfu of the corresponding strain suspended in the same vehicle. A significant increase of the suppressor-regulatory TGF-β cytokine occurred with both strains in comparison with a control (no intervention group of rats; the highest levels were reached in rats fed IPLA R1. This strain presented an immune protective profile, as it was able to reduce the production of the proinflammatory IL-6. Moreover, phosphorylated Akt kinase decreased in gastroctemius muscle of rats fed the strain IPLA R1, without affecting the glucose, insulin, and HOMA index in blood, or levels of Glut-4 located in the membrane of muscle and adipose tissue cells. Therefore, the strain B. animalis subsp. lactis IPLA R1 is a probiotic candidate to be tested in mild grade inflammation animal models.

  12. Análisis de la evidencia científica que sustenta la utilización de reclamos de salud presentes en la publicidad de alimentos de dos productos que contienen Lactobacillus cassei y Bifidobacterium lactis

    OpenAIRE

    Meléndez Illanes, Lorena

    2015-01-01

    Objetivo: Analizar la utilización de alegaciones a la salud en la publicidad de lácteos probióticos que contienen Lactobacillus cassei y Bifidobacterium lactis. Metodología: Publicaciones 1, 2 y 3: Se analizó la situación actual en la utilización de alegaciones a la salud que utilizan la industria en la publicidad de alimentos, tanto a nivel legislativo como de evidencia científica existente, para la posterior publicación de tres editoriales en revistas científicas. Publicación 4: Se realizó ...

  13. Exopolysaccharide-producing Bifidobacterium animalis subsp. lactis strains and their polymers elicit different responses on immune cells from blood and gut associated lymphoid tissue.

    Science.gov (United States)

    Hidalgo-Cantabrana, Claudio; Nikolic, Milica; López, Patricia; Suárez, Ana; Miljkovic, Marija; Kojic, Milan; Margolles, Abelardo; Golic, Natasa; Ruas-Madiedo, Patricia

    2014-04-01

    The effect of exopolysaccharide (EPS) producing bifidobacteria, and the EPS derived thereof, on the modulation of immune response was evaluated. Cells isolated from gut associated lymphoid tissue (GALT) and from peripheral blood mononuclear cells (PBMC) of naïve rats were used. The proliferation and cytokine production of these immune cells in the presence of the three isogenic Bifidobacterium animalis subsp. lactis strains (A1, A1dOx and A1dOxR), as well as their purified polymers, were in vitro analysed. The cytokine pattern produced by immune cells isolated from GALT showed that most levels remained stable in the presence of the three strains or their corresponding polymers. However, in PBMC the UV-inactivated bacteria induced higher levels of the ratios IFNγ/IL-17, TNFα/IL-10 and TNFα/TGFβ, and no variation in the ratio IFNγ/IL-4. Thus, B. animalis subsp. lactis strains were able to activate blood monocytes as well as T lymphocytes towards a mild inflammatory Th1 response. Furthermore, only the EPS-A1dOxR was able to stimulate a response in a similar way than its EPS-producing bacterium. Our work supports the notion that some bifidobacterial EPS could play a role in mediating the dialog of these microorganisms with the immune system. In addition, this study emphasizes the effect that the origin of the immune cells has in results obtained; this could explain the great amount of contradiction found in literature about the immunomodulation capability of EPS from probiotic bacteria. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Extraction of the same novel homoglycan mixture from two different strains of Bifidobacterium animalis and three strains of Bifidobacterium breve.

    Science.gov (United States)

    Alhudhud, M; Sadiq, S; Ngo, H N; Hidalgo-Cantabrana, C; Ruas-Madiedo, P; van Sinderen, D; Humphreys, P N; Laws, A P

    2018-04-26

    Three strains of Bifidobacterium breve (JCM 7017, JCM 7019 and JCM 2258) and two strains of Bifidobacterium animalis subsp. lactis (AD011 and A1dOxR) were grown in broth cultures or on plates, and a standard exopolysaccharide extraction method was used in an attempt to recover exocellular polysaccharides. When the extracted materials were analysed by NMR it was clear that mixtures of polysaccharides were being isolated including exopolysaccharides (EPS) cell wall polysaccharides and intracellular polysaccharides. Treatment of the cell biomass from the B. breve strains, or the B. animalis subsp. lactis AD011 strain, with aqueous sodium hydroxide provided a very similar mixture of polysaccharides but without the EPS. The different polysaccharides were partially fractionated by selective precipitation from an aqueous solution upon the addition of increasing percentages of ethanol. The polysaccharides extracted from B. breve JCM 7017 grown in HBM media supplemented with glucose (or isotopically labelled D-glucose-1- 13 C) were characterised using 1D and 2D-NMR spectroscopy. Addition of one volume of ethanol generated a medium molecular weight glycogen (Mw=1×10 5 Da, yield 200 mg/l). The addition of two volumes of ethanol precipitated an intimate mixture of a low molecular weight β-(1→6)-glucan and a low molecular weight β-(1→6)-galactofuranan which could not be separated (combined yield 46 mg/l). When labelled D-glucose-1- 13 C was used as a carbon supplement, the label was incorporated into >95% of the anomeric carbons of each polysaccharide confirming they were being synthesised in situ. Similar 1 H NMR profiles were obtained for polysaccharides recovered from the cells of B. animalis subsp. lactis AD011and A1dOxR (in combination with an EPS), B. breve JCM 7017, B. breve JCM 7019, B. breve JCM 2258 and from an EPS (-ve) mutant of B. breve 7017 (a non-EPS producer).

  15. Genetic analysis and morphological identification of pilus-like structures in members of the genus Bifidobacterium

    LENUS (Irish Health Repository)

    2011-08-30

    Abstract Background Cell surface pili in Gram positive bacteria have been reported to orchestrate the colonization of host tissues, evasion of immunity and the development of biofilms. So far, little if any information is available on the presence of pilus-like structures in human gut commensals like bifidobacteria. Results and discussion In this report, Atomic Force Microscopy (AFM) of various bifidobacterial strains belonging to Bifidobacterium bifidum, Bifidobacterium longum subsp. longum, Bifidobacterium dentium, Bifidobacterium adolescentis and Bifidobacterium animalis subsp. lactis revealed the existence of appendages resembling pilus-like structures. Interestingly, these microorganisms harbour two to six predicted pilus gene clusters in their genome, with each organized in an operon encompassing the major pilin subunit-encoding gene (designated fimA or fimP) together with one or two minor pilin subunit-encoding genes (designated as fimB and\\/or fimQ), and a gene encoding a sortase enzyme (strA). Quantitative Real Time (qRT)-PCR analysis and RT-PCR experiments revealed a polycistronic mRNA, encompassing the fimA\\/P and fimB\\/Q genes, which are differentially expressed upon cultivation of bifidobacteria on various glycans.

  16. Antibiotic resistance of lactic acid bacteria and Bifidobacterium spp. isolated from dairy and pharmaceutical products.

    Science.gov (United States)

    D'Aimmo, Maria Rosaria; Modesto, Monica; Biavati, Bruno

    2007-04-01

    The outlines of antibiotic resistance of some probiotic microorganisms were studied. This study was conducted with the double purpose of verifying their ability to survive if they are taken simultaneously with an antibiotic therapy and to increase the selective properties of suitable media for the isolation of samples containing mixed bacterial populations. We isolated from commercial dairy and pharmaceutical products, 34 strains declared as probiotics, belonging to the genera Bifidobacterium and Lactobacillus, and 21 strains of starter culture bacteria. All the microorganisms have been compared by electrophoresis of the soluble proteins for the purpose of identifying them. A Multiplex-PCR with genus- and species-specific primers was used to detect for Bifidobacterium animalis subsp. lactis presence. All bifidobacteria were B. animalis subsp. lactis except one Bifidobacterium longum. Sometimes the identification showed that the used strain was not the one indicated on the label. The lactobacilli were Lactobacillus acidophilus, Lactobacillus casei, and Lactobacillus delbrueckii subsp. bulgaricus. The streptococci were all Streptococcus thermophilus. The minimal inhibitory concentration (MIC) of 24 common antibiotic substances has been valued by the broth microdilution method. All tested strains were susceptible to ampicillin, bacitracin, clindamycin, dicloxacillin, erytromycin, novobiocin, penicillin G, rifampicin (MIC(90) ranging from 0.01 to 4 microg/ml); resistant to aztreonam, cycloserin, kanamycin, nalidixic acid, polymyxin B and spectinomycin (MIC(90) ranging from 64 to >1000 microg/ml). The susceptibility to cephalothin, chloramphenicol, gentamicin, lincomycin, metronidazole, neomycin, paromomycin, streptomycin, tetracycline and vancomycin was variable and depending on the species.

  17. Survival of Lactobacillus bulgaricus and Bifidobacterium animalis in yoghurts made from commercial starter cultures during refrigerated storage

    Directory of Open Access Journals (Sweden)

    Eva Dudriková

    2017-01-01

    Full Text Available All over the world, fermented dairy products have been consumed for nutrition and maintenance of good health for a very long time. This study evaluated the survival of Lactobacillus delbrueckii ssp. bulgaricus and Bifidobacterium animalis ssp. lactis BB-12 in yoghurts after the manufacturing during the shelf-life up to 21 days at 4 °C, which is mostly accepted by the consumers. The titratable acidity and pH showed the same patterns of increase or decline after manufacturing and storage of yoghurts. There was a significant difference (p <0.05 in acidity between yoghurts in glass bottle and plastic cup. The increase in numbers of lactobacilli and bifidobacteria and their survival during storage time were dependent on the species and strain of associative yoghurt bacteria (control-only yoghurt lactic acid bacteria and experimental containing except yoghurt culture also Bifidobacterium animalis ssp. lactis BB-12 and on the packaging material (glass bottle versus plastic cup. It was observed, that counts of bifidobacteria were lower than counts of Lactobacillus delbrueckii ssp. bulgaricus (190 to 434 x 107 at 1d and slowly increased (p <0.001 at maximum level on day 7 (294.3 - 754 x 107 and then slowly declined to 6.33 x 107 in glass bottle and 2.33 x 107 in plastic cups, respectively. Lactobacillus delbrueckii ssp. bulgaricus multiplied better in glass bottles than in plastic cups, as observed during experimental period in-group with Bifidobacterium animalis ssp. lactis BB-12. At the end of the storage period at 4 ºC, viable counts of lactobacilli were higher (p <0.001 in glass bottles. Al the yoghurts, contained the recommended levels of lactobacilli and bifidobacteria (107 cfu.g-1 at the end of storage period (21 d. 

  18. Salivary mutans streptococci and lactobacilli modulations in young children on consumption of probiotic ice-cream containing Bifidobacterium lactis Bb12 and Lactobacillus acidophilus La5.

    Science.gov (United States)

    Singh, Richa Polka; Damle, Satyawan Gangaram; Chawla, Amrita

    2011-11-01

    To compare the levels of mutans streptococci and lactobacilli in saliva of school children, before and after consumption of probiotic and control ice-cream. A double-blind, cross-over, placebo-controlled trial was carried out in forty, 12-14 year-old children, with no clinically detectable caries. The selected children were randomized equally into two groups I and II. Following an initial run-in period of 1 week, children in group I and II were given ice-creams 'A' and 'B', respectively, for 10 days. Being a cross-over study, the ice-creams were interchanged in the two groups after a 2-week wash-out period. Saliva samples at baseline and follow-up were assessed using Dentocult SM and Dentocult LB kits. On statistical evaluation, it was seen that probiotic ice-cream brought about a statistically significant reduction (p-value = 0.003) in salivary mutans streptococci levels with no significant effect on lactobacilli levels. In conclusion, probiotic ice-cream containing Bifidobacterium lactis Bb-12 ATCC27536 and Lactobacillus acidophilus La-5 can reduce the levels of certain caries-associated micro-organisms in saliva.

  19. Impact of Bifidobacterium animalis subsp. lactis BB-12 and, Lactobacillus acidophilus LA-5-containing yoghurt, on fecal bacterial counts of healthy adults.

    Science.gov (United States)

    Savard, Patricia; Lamarche, Benoît; Paradis, Marie-Eve; Thiboutot, Hélène; Laurin, Émilie; Roy, Denis

    2011-09-01

    This randomized, placebo-controlled, double blind, parallel dose-response study investigated the impact of 4-week commercial yoghurt consumption supplemented with Bifidobacterium animalis subsp. lactis (BB-12) and Lactobacillus acidophilus (LA-5) on fecal bacterial counts of healthy adults. Fifty-eight volunteers were randomly assigned to three different groups: 1. placebo (no probiotic, no starter and no green tea extract); 2. Yoptimal (10(9)cfu/100g of BB-12 and LA-5 and 40mg of green tea extract) and 3. Yoptimal-10 (10(10)cfu/100g of BB-12, 10(9)cfu/100g of LA-5 and 40mg of green tea extract). These yoghurt products also contained Lactobacillus delbrueckii subsp. bulgaricus (10(7)cfu/100g) and Streptococcus thermophilus (10(10)cfu/100g). The quantitative PCR (qPCR) results showed that there were significant increases (P=0.02) in bifidobacteria counts with the Yoptimal treatment as compared to baseline. The fecal numbers of B. animalis subsp. lactis and LA-5 significantly increased in the two probiotic treatments compared to the placebo treatment. Viable counts of fecal lactobacilli were significantly higher (P=0.05) and those of enterococci were significantly lower (P=0.04) after the intervention when compared to placebo. No significant difference was observed between treatments in volunteers' weight, waist girth, blood pressure, fasting plasma triglyceride and HDL-C concentrations, as well as cholesterol/HDL-cholesterol ratio. However, a significant increase in plasma cholesterol levels was observed in the placebo group (P=0.0018) but the levels remained stable in the two probiotic yoghurt groups. These results show that probiotic strains supplemented in the form of yoghurt remain active during gut transit and are associated with an increase in beneficial bacteria and a reduction in potentially pathogenic bacteria. This trial was registered at clinicaltrials.gov as NCT00730626. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Absolute Enumeration of Probiotic Strains Lactobacillus acidophilus NCFM® and Bifidobacterium animalis subsp. lactis Bl-04® via Chip-Based Digital PCR

    Directory of Open Access Journals (Sweden)

    Sarah J. Z. Hansen

    2018-04-01

    Full Text Available The current standard for enumeration of probiotics to obtain colony forming units by plate counts has several drawbacks: long time to results, high variability and the inability to discern between bacterial strains. Accurate probiotic cell counts are important to confirm the delivery of a clinically documented dose for its associated health benefits. A method is described using chip-based digital PCR (cdPCR to enumerate Bifidobacterium animalis subsp. lactis Bl-04 and Lactobacillus acidophilus NCFM both as single strains and in combination. Primers and probes were designed to differentiate the target strains against other strains of the same species using known single copy, genetic differences. The assay was optimized to include propidium monoazide pre-treatment to prevent amplification of DNA associated with dead probiotic cells as well as liberation of DNA from cells with intact membranes using bead beating. The resulting assay was able to successfully enumerate each strain whether alone or in multiplex. The cdPCR method had a 4 and 5% relative standard deviation (RSD for Bl-04 and NCFM, respectively, making it more precise than plate counts with an industry accepted RSD of 15%. cdPCR has the potential to replace traditional plate counts because of its precision, strain specificity and the ability to obtain results in a matter of hours.

  1. Effect of Lactobacillus rhamnosus and Bifidobacterium lactis on gingival health, dental plaque, and periodontopathogens in adolescents: a randomised placebo-controlled clinical trial.

    Science.gov (United States)

    Alanzi, A; Honkala, S; Honkala, E; Varghese, A; Tolvanen, M; Söderling, E

    2018-04-10

    To determine the effect of a probiotic combination of Lactobacillus rhamnosus GG (LGG) and Bifidobacterium lactis BB-12 on the gingival health, dental plaque accumulation, and the oral carriage of four putative periodontal pathogens in healthy adolescents. 108 schoolboys, aged 13-15 years, participated in this study. They were divided into two groups: probiotics (n=54) and placebo (n=54). Both groups received two probiotic-laced or placebo lozenges twice a day during a four-week period. Plaque Index (PI) and Gingival Index (GI) were recorded at baseline and after four weeks. Salivary and plaque carriage of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum were also monitored likewise. 101 subjects completed the study. A statistically significant reduction in GI was seen in the probiotic group as compared to the placebo group (P=0.012). A reduction in PI was found for both groups, with no difference observed between the groups after intervention (P=0.819). Probiotic lozenges significantly reduced levels of A. actinomycetemcomitans and F. nucleatum in saliva and plaque (Pplaque (Pbacterial counts of the test group. The short-term daily consumption of LGG and BB-12 probiotic lozenges improved the gingival health in adolescents and decreased the microbial counts of A. actinomycetemcomitans, and P. gingivalis. Hence probiotic supplements may serve as a simple adjunct to standard oral care for promoting the oral health in adolescents.

  2. Bifidobacteria

    Science.gov (United States)

    ... Bifidobactéries, Bifidobacterium, Bifidobacterium adolescentis; Bifidobacterium animalis, Bifidobacterium bifidum; Bifidobacterium breve; Bifidobacterium infantis; Bifidobacterium lactis; Bifidobacterium longum, Bifidum, Bifidus, ...

  3. Tulum Peynirlerinden izole Edilen Lactococcus lactis subsp. lactis YBML9 ve

    Directory of Open Access Journals (Sweden)

    Yasin TUNCER

    2009-04-01

    Full Text Available Bu çalısmanın amacı tulum peynirlerinden izole edilen Lactococcus lactis suslarının fenotipik tanısı ve bu suslar tarafından üretilen bakteriyosinlerin kısmi karakterizasyonlarıdır. Bu amaçla Türkiye'nin sekiz farklı ilinden (Ankara, Antalya, Burdur, Denizli, Erzincan, Isparta, İstanbul ve İzmir yöresel pazarlardan toplanan 60 adet tulum peyniri örneginden 40 adet Lactococcus lactis susu (31 adet L. lactis subsp. lactis ve 9 adet L. lactis subsp. cremoris izole edildi. 40 adet L. lactis susu içerisinden, 2 adet L. lactis subsp. lactis (YBML9 ve YBML21 susu bakteriyosin üretme yeteneginde bulundu. L. lactis subsp. lactis YBML9 ve YBML21 susları tarafından üretilen bakteriyosinler, farklı enzim, pH ve sıcaklık uygulamaları sonucu; sırasıyla nisin ve laktisin 481 olarak tanımlandı.

  4. Effect of Bifidobacterium upon Clostridium difficile growth and toxicity when co-cultured in different prebiotic substrates

    Directory of Open Access Journals (Sweden)

    Lorena Valdés Varela

    2016-05-01

    Full Text Available The intestinal overgrowth of Clostridium difficile, often after disturbance of the gut microbiota by antibiotic treatment, leads to C. difficile infection (CDI which manifestation ranges from mild diarrhoea to life-threatening conditions. The increasing CDI incidence, not only in compromised subjects but also in traditionally considered low-risk populations, together with the frequent relapses of the disease, has attracted the interest for prevention/therapeutic options. Among these, probiotics, prebiotics or synbiotics constitute a promising approach. In this study we determined the potential of selected Bifidobacterium strains for the inhibition of C. difficile growth and toxicity in different carbon sources. We conducted co-cultures of the toxigenic strain C. difficile LMG21717 with four Bifidobacterium strains (Bifidobacterium longum IPLA20022, Bifidobacterium breve IPLA20006, Bifidobacterium bifidum IPLA20015, and Bifidobacterium animalis subsp. lactis Bb12 in the presence of various prebiotic substrates (Inulin, Synergy and Actilight or glucose, and compared the results with those obtained for the corresponding mono-cultures. C. difficile and bifidobacteria levels were quantified by qPCR; the pH and the production of short chain fatty acids was also determined. Moreover, supernatants of the cultures were collected to evaluate their toxicity using a recently developed model. Results showed that co-culture with B. longum IPLA20022 and B. breve IPLA20006 in the presence of short-chain fructooligosaccharides, but not of Inulin, as carbon source significantly reduced the growth of the pathogen. With the sole exception of B. animalis Bb12, whose growth was enhanced, the presence of C. difficile did not show major effects upon the growth of the bifidobacteria. In accordance with the growth data, B. longum and B. breve were the strains showing higher reduction in the toxicity of the co-culture supernatants.

  5. Probiotic bacteria Lactobacillus acidophilus NCFM and Bifidobacterium lactis Bi-07 versus placebo for the symptoms of bloating in patients with functional bowel disorders: a double-blind study.

    Science.gov (United States)

    Ringel-Kulka, Tamar; Palsson, Olafur S; Maier, Danielle; Carroll, Ian; Galanko, Joseph A; Leyer, Gregory; Ringel, Yehuda

    2011-07-01

    Recent data suggest a role for the intestinal microbiota in the pathogenesis of functional bowel disorders (FBDs). Probiotic studies in FBDs generated inconsistent results suggesting a strain-specific and product-specific effect. To investigate the clinical efficacy of Lactobacillus acidophilus NCFM (L-NCFM) and Bifidobacterium lactis Bi-07 (B-LBi07) in nonconstipation FBDs. A double-blind, placebo-control clinical trial of the probiotic bacterias L-NCFM and B-LBi07 twice a day (2×10(11) CFU/d) versus placebo over 8 weeks. Primary endpoints were global relief of gastrointestinal symptoms and satisfaction with treatment. Secondary endpoints were change in symptoms severity, well-being, and quality of life. Microbiological effect was assessed by quantitative real time polymerase chain reaction on fecal samples. Sixty patients (probiotic, n=31; placebo, n=29), 72% females, 84% whites, mean age 37 years. Abdominal bloating improved in the probiotics compared with the placebo group at 4 weeks (4.10 vs 6.17, P=0.009; change in bloating severity P=0.02) and 8 weeks (4.26 vs 5.84, P=0.06; change in bloating severity Pbacteria in the pathophysiology of FBD and the role for probiotic bacteria in the management of these disorders.

  6. Comparative Phenotypic and Molecular Genetic Profiling of Wild Lactococcus lactis subsp. lactis Strains of the L. lactis subsp. lactis and L. lactis subsp. cremoris Genotypes, Isolated from Starter-Free Cheeses Made of Raw Milk▿

    Science.gov (United States)

    Fernández, Elena; Alegría, Ángel; Delgado, Susana; Martín, M. Cruz; Mayo, Baltasar

    2011-01-01

    Twenty Lactococcus lactis strains with an L. lactis subsp. lactis phenotype isolated from five traditional cheeses made of raw milk with no added starters belonging to the L. lactis subsp. lactis and L. lactis subsp. cremoris genotypes (lactis and cremoris genotypes, respectively; 10 strains each) were subjected to a series of phenotypic and genetic typing methods, with the aims of determining their phylogenetic relationships and suitability as starters. Pulsed-field gel electrophoresis (PFGE) analysis of intact genomes digested with SalI and SmaI proved that all strains were different except for three isolates of the cremoris genotype, which showed identical PFGE profiles. Multilocus sequence typing (MLST) analysis using internal sequences of seven loci (namely, atpA, rpoA, pheS, pepN, bcaT, pepX, and 16S rRNA gene) revealed considerable intergenotype nucleotide polymorphism, although deduced amino acid changes were scarce. Analysis of the MLST data for the present strains and others from other dairy and nondairy sources showed that all of them clustered into the cremoris or lactis genotype group, by using both independent and combined gene sequences. These two groups of strains also showed distinctive carbohydrate fermentation and enzyme activity profiles, with the strains in the cremoris group showing broader profiles. However, the profiles of resistance/susceptibility to 16 antibiotics were very similar, showing no atypical resistance, except for tetracycline resistance in three identical cremoris genotype isolates. The numbers and concentrations of volatile compounds produced in milk by the strains belonging to these two groups were clearly different, with the cremoris genotype strains producing higher concentrations of more branched-chain, derived compounds. Together, the present results support the idea that the lactis and cremoris genotypes of phenotypic Lactococcus lactis subsp. lactis actually represent true subspecies. Some strains of the two subspecies

  7. EVIDENCE-BASED DATA ON EFFECTIVENESS OF LACTOBACILLUS RHAMNOSUS GG AND BIFIDOBACTERIUM LACTIS ВB-12 IN PEDIATRIC PRACTICE

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    I. V. Andreyeva

    2011-01-01

    Full Text Available Prophylactic and therapeutic administration of prebiotics in treatment of different disorders is used very often nowadays. However, this kind of a treatment confirmed its efficacy in only several diseases. The review presents the data on efficacy of two probiotic microorganisms (L. rhamnosus GG and B. lactis Вb-12 in pediatric practice. Author summarizes and analyzes existing evidence-based data on efficacy of probiotics in treatment of acute diarrhea, prophylaxis of antibiotic-associated diarrhea and nosocomial infections. L. rhamnosus GG and B. lactis Вb-12 have their own place in prophylaxis of infections of airways and gastrointestinal tract. Administration of probiotics for treatment and prophylaxis of allergic and other diseases is reviewed. Safety of probiotics is described as well.

  8. Bifidobacterium reuteri sp. nov., Bifidobacterium callitrichos sp. nov., Bifidobacterium saguini sp. nov., Bifidobacterium stellenboschense sp. nov. and Bifidobacterium biavatii sp. nov. isolated from faeces of common marmoset (Callithrix jacchus) and red-handed tamarin (Saguinus midas).

    Science.gov (United States)

    Endo, Akihito; Futagawa-Endo, Yuka; Schumann, Peter; Pukall, Rüdiger; Dicks, Leon M T

    2012-03-01

    Five strains of bifidobacteria were isolated from faeces of a common marmoset (Callithrix jacchus) and a red-handed tamarin (Saguinus midas). The five isolates clustered inside the phylogenetic group of the genus Bifidobacterium but did not show high sequence similarities between the isolates and to known species in the genus by phylogenetic analysis based on 16S rRNA gene sequences. Sequence analyses of dnaJ1 and hsp60 also indicated their independent phylogenetic positions to each other in the Bifidobacterium cluster. DNA G+C contents of the species ranged from 57.3 to 66.3 mol%, which is within the values recorded for Bifidobacterium species. All isolates showed fructose-6-phosphate phosphoketolase activity. Based on the data provided, the five isolates represent five novel species, for which the names Bifidobacterium reuteri sp. nov. (type strain: AFB22-1(T) = JCM 17295(T) = DSM 23975(T)), Bifidobacterium callitrichos sp. nov. (type strain: AFB22-5(T) = JCM 17296(T) = DSM 23973(T)), Bifidobacterium saguini sp. nov. (type strain: AFB23-1(T) = JCM 17297(T) = DSM 23967(T)), Bifidobacterium stellenboschense sp. nov. (type strain: AFB23-3(T) = JCM 17298(T) = DSM 23968(T)) and Bifidobacterium biavatii sp. nov. (type strain: AFB23-4(T) = JCM 17299(T) = DSM 23969(T)) are proposed. Copyright © 2011 Elsevier GmbH. All rights reserved.

  9. Lactococcus lactis expressing food-grade β-galactosidase alleviates lactose intolerance symptoms in post-weaning Balb/c mice.

    Science.gov (United States)

    Li, Jingjie; Zhang, Wen; Wang, Chuan; Yu, Qian; Dai, Ruirui; Pei, Xiaofang

    2012-12-01

    The endogenous β-galactosidase expressed in intestinal microbes is demonstrated to help humans in lactose usage, and treatment associated with the promotion of beneficial microorganism in the gut is correlated with lactose tolerance. From this point, a kind of recombinant live β-galactosidase delivery system using food-grade protein expression techniques and selected probiotics as vehicle was promoted by us for the purpose of application in lactose intolerance subjects. Previously, a recombinant Lactococcus lactis MG1363 strain expressing food-grade β-galactosidase, the L. lactis MG1363/FGZW, was successfully constructed and evaluated in vitro. This study was conducted to in vivo evaluate its efficacy on alleviating lactose intolerance symptoms in post-weaning Balb/c mice, which were orally administered with 1 × 10⁶ CFU or 1 × 10⁸ CFU of L. lactis MG1363/FGZW daily for 4 weeks before lactose challenge. In comparison with naïve mice, the mice administered with L. lactis MG1363/FGZW showed significant alleviation of diarrhea symptoms in less total feces weight within 6 h post-challenge and suppressed intestinal motility after lactose challenge, although there was no significant increase of β-galactosidase activity in small intestine. The alleviation also correlated with higher species abundance, more Bifidobacterium colonization, and stronger colonization resistance in mice intestinal microflora. Therefore, this recombinant L. lactis strain effectively alleviated diarrhea symptom induced by lactose uptake in lactose intolerance model mice with the probable mechanism of promotion of lactic acid bacteria to differentiate and predominantly colonize in gut microbial community, thus making it a promising probiotic for lactose intolerance subjects.

  10. FORMULASI PRODUK SUSU FERMENTASI KERING DENGAN PENAMBAHAN BAKTERI PROBIOTIK Lactobacillus casei DAN Bifidobacterium longum

    Directory of Open Access Journals (Sweden)

    Dida Hani Rahman

    2012-11-01

    Full Text Available ABSTRACTFermented milk is a healthy product that has many benefits especially for human digestive tract. Manufacturing of probiotic fermented milk products as a functional food with a viable long shelf life needs to be developed. The purpose of this study was to formulate a dried fermented milk product using probiotic bacterias. The experimental design study was a complete random design with 4 treatments using different lactic acid bacteria (LAB: A1 (Streptococcus lactis: 0.5%; A2 (Streptococcus lactis: 0.25% and Lactobacillus casei: 0.25%; A3 (Streptococcus lactis: 0.25%, Lactobacillus bulgaricus: 0.125%, Streptococcus thermophiles: 0.125%; and A4 (Streptococcus lactis: 0.25% and Bifidobacterium longum: 0.25%. The highest level of hardness was A2 product and the highest level of tenderness is A1 product. Results of proximate analysis showed that dried fermented milk products had high levels of the protein, calcium, and phosphorus. Microbiological test results showed that the amount of lactic acid bacteria (BAL in dried fermented milk products were eligible based on CODEX: 243 (2003. Statictical analysis using ANOVA in the hedonic quality test showed that the treatments were significantly different (p 0.05 on the attributes of color, aroma, hardness, and flavor except texture.Key words: dried fermented milk, functional food, probiotic, lactic acid bacteria (LABABSTRAKSusu fermentasi merupakan produk kesehatan yang mempunyai banyak manfaat terutama untuk saluran pencernaan manusia. Pembuatan produk susu fermentasi probiotik sebagai makanan fungsional yang mempunyai kelangsungan hidup dan daya simpan yang lama perlu dikembangan. Tujuan penelitian ini adalah untuk memformulasikan susu fermentasi kering menggunakan bakteri probiotik. Desain penelitian yang digunakan adalah rancangan acak lengkap dengan 4 perlakuan menggunakan 4 bakteri asam laktat (BAL, (Streptococcus lactis, 0.5%, A2 (Streptococcus lactis; 0.25% dan Lactobacillus casei; 0.25%, A3

  11. Viability of probiotic (Bifidobacterium, Lactobacillus acidophilus and Lactobacillus casei) and nonprobiotic microflora in Argentinian Fresco cheese.

    Science.gov (United States)

    Vinderola, C G; Prosello, W; Ghiberto, T D; Reinheimer, J A

    2000-09-01

    We evaluated the suitability of Argentinian Fresco cheese as a food carrier of probiotic cultures. We used cultures of Bifidobacterium bifidum (two strains), Bifidobacterium longum (two strains), Bifidobacterium sp. (one strain), Lactobacillus acidophilus (two strains), and Lactobacillus casei (two strains) in different combinations, as probiotic adjuncts. Probiotic, lactic starter (Lactococcus lactis and Streptococcus thermophilus), and contaminant (coliforms, yeasts, and molds) organisms were counted at 0, 30, and 60 d of refrigerated storage. Furthermore, the acid resistance of probiotic and starter bacteria was determined from hydrochloric solutions (pH 2 and 3) of Fresco cheese. The results showed that nine different combinations of bifidobacteria and L. acidophilus had a satisfactory viability (count decreases in 60 d casei cultures assayed also showed a satisfactory survival (counts decreased casei). On the other hand, the three combinations of bifidobacteria, L. acidophilus, and L. casei tested adapted well to the Fresco cheese environment. When a cheese homogenate at pH 3 was used to partially simulate the acidic conditions in the stomach, the probiotic cultures had an excellent ability to remain viable up to 3 h. At pH 2, the cell viability was more affected; B. bifidum was the most resistant organism. This study showed that the Argentinian Fresco cheese could be used as an adequate carrier of probiotic bacteria.

  12. Enhancing bile tolerance improves survival and persistence of Bifidobacterium and Lactococcus in the murine gastrointestinal tract

    Directory of Open Access Journals (Sweden)

    Hill Colin

    2008-10-01

    Full Text Available Abstract Background The majority of commensal gastrointestinal bacteria used as probiotics are highly adapted to the specialised environment of the large bowel. However, unlike pathogenic bacteria; they are often inadequately equipped to endure the physicochemical stresses of gastrointestinal (GI delivery in the host. Herein we outline a patho-biotechnology strategy to improve gastric delivery and host adaptation of a probiotic strain Bifidobacterium breve UCC2003 and the generally regarded as safe (GRAS organism Lactococcus lactis NZ9000. Results In vitro bile tolerance of both strains was significantly enhanced (P Listeria monocytogenes bile resistance mechanism BilE. Strains harbouring bilE were also recovered at significantly higher levels (P n = 5, following oral inoculation. Furthermore, a B. breve strain expressing bilE demonstrated increased efficacy relative to the wild-type strain in reducing oral L. monocytogenes infection in mice. Conclusion Collectively the data indicates that bile tolerance can be enhanced in Bifidobacterium and Lactococcus species through rational genetic manipulation and that this can significantly improve delivery to and colonisation of the GI tract.

  13. Lactococcus lactis ssp. lactis as Potential Functional Starter Culture

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    Jelena Cvrtila

    2014-01-01

    Full Text Available The aim of this study is to identify and characterise potential autochthonous functional starter cultures in homemade horsemeat sausage. The dominant microflora in the samples of horsemeat sausage were lactic acid bacteria (LAB, followed by micrococci. Among the LAB, Lactococcus lactis ssp. lactis and Lactobacillus plantarum were the dominant species, and since the first is not common in fermented sausages, we characterised it as a potential functional starter culture. Lactococcus lactis ssp. lactis produced a significant amount of lactic acid, displayed good growth capability at 12, 18 and 22 °C, growth in the presence of 5 % NaCl, good viability after lyophilisation and in simulated gastric and small intestinal juice, antimicrobial activity against test pathogens, and good adhesive properties in vitro.

  14. Cloning, Sequencing, and Expression of the Pyruvate Carboxylase Gene in Lactococcus lactis subsp. lactis C2†

    OpenAIRE

    Wang, H.; O'Sullivan, D. J.; Baldwin, K. A.; McKay, L. L.

    2000-01-01

    A functional pyc gene was isolated from Lactococcus lactis subsp. lactis C2 and was found to complement a Pyc defect in L. lactis KB4. The deduced lactococcal Pyc protein was highly homologous to Pyc sequences of other bacteria. The pyc gene was also detected in Lactococcus lactis subsp. cremoris and L. lactis subsp. lactis bv. diacetylactis strains.

  15. Obesity-associated gut microbiota is enriched in Lactobacillus reuteri and depleted in Bifidobacterium animalis and Methanobrevibacter smithii.

    Science.gov (United States)

    Million, M; Maraninchi, M; Henry, M; Armougom, F; Richet, H; Carrieri, P; Valero, R; Raccah, D; Vialettes, B; Raoult, D

    2012-06-01

    Obesity is associated with increased health risk and has been associated with alterations in bacterial gut microbiota, with mainly a reduction in Bacteroidetes, but few data exist at the genus and species level. It has been reported that the Lactobacillus and Bifidobacterium genus representatives may have a critical role in weight regulation as an anti-obesity effect in experimental models and humans, or as a growth-promoter effect in agriculture depending on the strains. To confirm reported gut alterations and test whether Lactobacillus or Bifidobacterium species found in the human gut are associated with obesity or lean status, we analyzed the stools of 68 obese and 47 controls targeting Firmicutes, Bacteroidetes, Methanobrevibacter smithii, Lactococcus lactis, Bifidobacterium animalis and seven species of Lactobacillus by quantitative PCR (qPCR) and culture on a Lactobacillus-selective medium. In qPCR, B. animalis (odds ratio (OR)=0.63; 95% confidence interval (CI) 0.39-1.01; P=0.056) and M. smithii (OR=0.76; 95% CI 0.59-0.97; P=0.03) were associated with normal weight whereas Lactobacillus reuteri (OR=1.79; 95% CI 1.03-3.10; P=0.04) was associated with obesity. The gut microbiota associated with human obesity is depleted in M. smithii. Some Bifidobacterium or Lactobacillus species were associated with normal weight (B. animalis) while others (L. reuteri) were associated with obesity. Therefore, gut microbiota composition at the species level is related to body weight and obesity, which might be of relevance for further studies and the management of obesity. These results must be considered cautiously because it is the first study to date that links specific species of Lactobacillus with obesity in humans.

  16. Genome Sequence of Lactococcus lactis subsp. lactis NCDO 2118, a GABA-Producing Strain

    DEFF Research Database (Denmark)

    Oliveira, Letícia C; Saraiva, Tessália D L; Soares, Siomar C

    2014-01-01

    Lactococcus lactis subsp. lactis NCDO 2118 is a nondairy lactic acid bacterium, a xylose fermenter, and a gamma-aminobutyric acid (GABA) producer isolated from frozen peas. Here, we report the complete genome sequence of L. lactis NCDO 2118, a strain with probiotic potential activity....

  17. Isolation and molecular identification of lactic acid bacteria and Bifidobacterium spp. from faeces of the blue-fronted Amazon parrot in Brazil.

    Science.gov (United States)

    Allegretti, L; Revolledo, L; Astolfi-Ferreira, C S; Chacón, J L; Martins, L M; Seixas, G H F; Ferreira, A J P

    2014-12-01

    In Brazil, the blue-fronted Amazon parrot (Amazona aestiva) is a common pet. The faecal microbiota of these birds include a wide variety of bacterial species, the majority of which belong to the Gram-positive lactic acid bacteria (LAB) clade. The aim of this study was to investigate differences in the diversity and abundance of LAB and Bifidobacterium spp. in the cloacae between wild and captive birds and to select, identify and characterise LAB for consideration as a parrot probiotic. Cloacal swabs were collected from 26 wild and 26 captive birds. Bacterial DNA was extracted, and the 16S rRNA genes were amplified. The numbers of PCR-positive Enterococcus, Pediococcus, and Lactobacillus species isolated from wild and captive birds were significantly different (PLactobacillus, Lactococcus and Bifidobacterium. Enterococcus faecium, Pediococcus pentosaceus, Lactococcus lactis, Lactobacillus coryniformis, Lactobacillus sanfranciscensis and Bifidobacterium bifidum were the most frequently isolated species from all birds. This study increases our understanding of the faecal microbiota, and may help to improve the nutrition and habitat management of captive and wild parrots. The bacterial population identified in the faecal microbiota of clinically healthy wild and captive parrots can serve as a database to analyse variations in the gut microbiota of pathogen-infected parrots and to develop probiotics specific to these genera.

  18. Lactococcus lactis is diploid

    DEFF Research Database (Denmark)

    Michelsen, Ole; Jensen, Peter Ruhdal

    As part of a collaboration with Danish Dairy Research Foundation we are interested in the DNA replication of Lactococcus lactis. For that we implemented flowcytometric analysis for these studies. The L. lactis does not respond to inhibition by rifampicin by finishing ongoing replication forks. We....... This unexpected result has been confirmed by radioactive labelling of slow growing cultures of Lactococcus lactis, which also showed the presence of two chromosomes. We therefore conclude that Lactococcus lactis is the first diploid bacterium found....... therefore turned to slow growing cultures in order to obtain information about the DNA replication in the cell cycle. From these studies we have obtained evidence that suggest that slow growing L. lactis are born with two chromosomes in contrast to other studied bacteria, which are born with one chromosome...

  19. Multilocus sequence typing of Lactococcus lactis from naturally fermented milk foods in ethnic minority areas of China.

    Science.gov (United States)

    Xu, Haiyan; Sun, Zhihong; Liu, Wenjun; Yu, Jie; Song, Yuqin; Lv, Qiang; Zhang, Jiachao; Shao, Yuyu; Menghe, Bilige; Zhang, Heping

    2014-05-01

    To determine the genetic diversity and phylogenetic relationships among Lactococcus lactis isolates, 197 strains isolated from naturally homemade yogurt in 9 ethnic minority areas of 6 provinces of China were subjected to multilocus sequence typing (MLST). The MLST analysis was performed using internal fragment sequences of 12 housekeeping genes (carB, clpX, dnaA, groEL, murC, murE, pepN, pepX, pyrG, recA, rpoB, and pheS). Six (dnaA) to 8 (murC) different alleles were detected for these genes, which ranged from 33.62 (clpX) to 41.95% (recA) GC (guanine-cytosine) content. The nucleotide diversity (π) ranged from 0.00362 (murE) to 0.08439 (carB). Despite this limited allelic diversity, the allele combinations of each strain revealed 72 different sequence types, which denoted significant genotypic diversity. The dN/dS ratios (where dS is the number of synonymous substitutions per synonymous site, and dN is the number of nonsynonymous substitutions per nonsynonymous site) were lower than 1, suggesting potential negative selection for these genes. The standardized index of association of the alleles IA(S)=0.3038 supported the clonality of Lc. lactis, but the presence of network structure revealed by the split decomposition analysis of the concatenated sequence was strong evidence for intraspecies recombination. Therefore, this suggests that recombination contributed to the evolution of Lc. lactis. A minimum spanning tree analysis of the 197 isolates identified 14 clonal complexes and 23 singletons. Phylogenetic trees were constructed based on the sequence types, using the minimum evolution algorithm, and on the concatenated sequence (6,192 bp), using the unweighted pair-group method with arithmetic mean, and these trees indicated that the evolution of our Lc. lactis population was correlated with geographic origin. Taken together, our results demonstrated that MLST could provide a better understanding of Lc. lactis genome evolution, as well as useful information for

  20. High efficiency electrotransformation of Lactococcus lactis spp. lactis cells pretreated with lithium acetate and dithiothreitol

    Directory of Open Access Journals (Sweden)

    Filioussis George

    2007-03-01

    Full Text Available Abstract Background A goal for the food industry has always been to improve strains of Lactococcus lactis and stabilize beneficial traits. Genetic engineering is used extensively for manipulating this lactic acid bacterium, while electropolation is the most widely used technique for introducing foreign DNA into cells. The efficiency of electrotransformation depends on the level of electropermealization and pretreatment with chemicals which alter cell wall permeability, resulting in improved transformation efficiencies is rather common practice in bacteria as in yeasts and fungi. In the present study, treatment with lithium acetate (LiAc and dithiothreitol (DTT in various combinations was applied to L. lactis spp. lactis cells of the early-log phase prior to electroporation with plasmid pTRKH3 (a 7.8 kb shuttle vector, suitable for cloning into L. lactis. Two strains of L. lactis spp. lactis were used, L. lactis spp. lactis LM0230 and ATCC 11454. To the best of our knowledge these agents have never been used before with L. lactis or other bacteria. Results Electrotransformation efficiencies of up to 105 transformants per μg DNA have been reported in the literature for L. lactis spp.lactis LM0230. We report here that treatment with LiAc and DDT before electroporation increased transformation efficiency to 225 ± 52.5 × 107 transformants per μg DNA, while with untreated cells or treated with LiAc alone transformation efficiency approximated 1.2 ± 0.5 × 105 transformants per μg DNA. Results of the same trend were obtained with L. lactis ATCC 11454, although transformation efficiency of this strain was significantly lower. No difference was found in the survival rate of pretreated cells after electroporation. Transformation efficiency was found to vary directly with cell density and that of 1010 cells/ml resulted in the highest efficiencies. Following electrotransformation of pretreated cells with LiAc and DDT, pTRKH3 stability was examined

  1. Phenotypic variation in Lactococcus lactis subsp. lactis isolates derived from intestinal tracts of marine and freshwater fish.

    Science.gov (United States)

    Itoi, S; Yuasa, K; Washio, S; Abe, T; Ikuno, E; Sugita, H

    2009-09-01

    We compared phenotypic characteristics of Lactococcus lactis subsp. lactis derived from different sources including the intestinal tract of marine fish and freshwater fish, and cheese starter culture. In the phylogenetic analysis based on partial 16S rRNA gene nucleotide sequences (1371 bp), freshwater fish-, marine fish- and cheese starter culture-derived strains were identical to that of L. lactis subsp. lactis previously reported. Fermentation profiles determined using the API 50 CH system were similar except for fermentation of several sugars including l-arabinose, mannitol, amygdalin, saccharose, trehalose, inulin and gluconate. The strains did have distinct levels of halotolerance: marine fish-derived strains > cheese starter-derived strain > freshwater fish-derived isolate. Lactococcus lactis subsp. lactis showed extensive diversity in phenotypic adaptation to various environments. The phenotypic properties of these strains suggested that L. lactis subsp. lactis strains from fish intestine have additional functions compared with the cheese starter-derived strain that has previously described. The unique phenotypic traits of the fish intestinal tract-derived L. lactis subsp. lactis might make them useful as a probiotics in aquaculture, and contribute to the development of functional foods and novel food additives, since the strains derived from fish intestines might have additional functions such as antibacterial activity.

  2. Discovering Novel Bile Protection Systems in Bifidobacterium breve UCC2003 through Functional Genomics

    Science.gov (United States)

    Ruiz, Lorena; Zomer, Aldert; O'Connell-Motherway, Mary; van Sinderen, Douwe

    2012-01-01

    Tolerance of gut commensals to bile salt exposure is an important feature for their survival in and colonization of the intestinal environment. A transcriptomic approach was employed to study the response of Bifidobacterium breve UCC2003 to bile, allowing the identification of a number of bile-induced genes with a range of predicted functions. The potential roles of a selection of these bile-inducible genes in bile protection were analyzed following heterologous expression in Lactococcus lactis. Genes encoding three transport systems belonging to the major facilitator superfamily (MFS), Bbr_0838, Bbr_0832, and Bbr_1756, and three ABC-type transporters, Bbr_0406-0407, Bbr_1804-1805, and Bbr_1826-1827, were thus investigated and shown to provide enhanced resistance and survival to bile exposure. This work significantly improves our understanding as to how bifidobacteria respond to and survive bile exposure. PMID:22156415

  3. Protein Profile and Plasmid Content of Lactococcus lactis subsp. lactis LL52 and Lactococcus lactis subsp. cremoris LC79 Strains under Several Stress Conditions

    OpenAIRE

    LALE, Rahmi; TÜKEL, Çağla; AKÇELİK, Mustafa

    2014-01-01

    Differences in the protein and plasmid content of 2 Lactococcus lactis strains, L. lactis subsp. lactis LL52 and L. lactis subsp. cremoris LC79, under the stresses of high and low temperature, osmotic shock, and low pH were determined. We identified 3 new proteins with molecular masses of 16.0, 29.4, and 45.0 kDa as high temperature stress response specific in strain LL52. High temperature stress did not cause any changes in the protein content of strain LC79. Proteins that were specific for ...

  4. Cadmium tolerant characteristic of a newly isolated Lactococcus lactis subsp. lactis.

    Science.gov (United States)

    Sheng, Yao; Wang, Ying; Yang, Xuan; Zhang, Boyang; He, Xiaoyun; Xu, Wentao; Huang, Kunlun

    2016-12-01

    Environmental contamination caused by heavy metals poses a major threat to the wildlife and human health for their toxicity and intrinsically persistent nature. Some specific food grade bacteria have properties that enable them to eliminate heavy metals from food and water. Lactococcus lactis subsp. lactis, newly isolated from pickles, is a cadmium (Cd) tolerant bacteria. Cd resistant properties of the lactis was evaluated under different Cd stresses. Cd accumulation in different cellular parts was determined by ICP-MS and cell morphology changes were measured by SEM-EDS and TEM-EDS. In addition, functional groups associated with Cd resistance were detected by infrared spectroscopic analysis. The results indicated that Cd mainly accumulated in the cell surface structures including cytoderm and cytomembrane. Functional groups such as OH and NH 2 in the cell surface played essential roles in Cd biosorption. The elements of O, P, S, and N of polysaccharide, membrane protein and phosphatidate in the cell surface structures might be responsible for Cd biosorption for their strong electronegativity. This study indicated that ultrastructural analysis can be a supplemental method to study heavy metal resistance mechanism of microorganism and the newly isolated lactococcus lactis subsp. lactis has great potential to be applied to decontamination of heavy metals. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Enhanced production of nisin by co-culture of Lactococcus lactis sub sp. lactis and Yarrowia lipolytica in molasses based medium.

    Science.gov (United States)

    Ariana, Mehdi; Hamedi, Javad

    2017-08-20

    Nisin is a safe, approved and commercial bacteriocin that is produced by Lactococcus lactis subsp. lactis. Since lactate accumulation in fermentation medium reduces L. lactis growth and nisin production, Yarrowia lipolytica, a lactate consuming yeast and L. lactis subsp. lactis, were simultaneously cultured in a molasses based medium. Y. lipolytica is not able to consume sucrose as carbon source, but rather consumes lactate and hence decrease lactic acid titer by 10% in the medium. Lactic acid consumption, 15% increased pH value and stimulated L. lactis growth. In the mixed culture, nisin production and L. lactis growth were 50% and 49% higher than that of pure culture, respectively. Also the results showed that specific growth rate of L. lactis increased 4 times more than that of the pure culture. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Promotion of intestinal peristalsis by Bifidobacterium spp. capable of hydrolysing sennosides in mice.

    Science.gov (United States)

    Matsumoto, Mitsuharu; Ishige, Atsushi; Yazawa, Yuka; Kondo, Manami; Muramatsu, Koji; Watanabe, Kenji

    2012-01-01

    While there are a variety of identifiable causes of constipation, even idiopathic constipation has different possible mechanisms. Sennosides, the main laxative constituents of Daio, an ancient Kampo medicine, are prodrugs that are converted to an active principle, rheinanthrone, by intestinal microbiota. In this study, we aimed to determine the sennoside hydrolysis ability of lactic acid bacterial strains and bifidobacteria in the intestine and to investigate their effect on intestinal peristalsis in mice. A total of 88 lactic acid bacterial strains and 47 bifidobacterial strains were evaluated for their ability to hydrolyze sennosides. Our results revealed that 4 strains, all belonging to the genus Bifidobacterium, had strong sennoside hydrolysis ability, exhibiting a decrease of >70% of sennoside content. By thin-layer chromatography analysis, rheinanthrone was detected in the medium cultured with B. pseudocatenulatum LKM10070 and B. animalis subsp. lactis LKM512. The fecal sennoside contents significantly (Psennoside by strain LKM512 and LKM10070.

  7. Selective method for identification and quantification of Bifidobacterium animalis subspecies lactis BB-12 (BB-12) from the gastrointestinal tract of healthy volunteers ingesting a combination probiotic of BB-12 and Lactobacillus rhamnosus GG.

    Science.gov (United States)

    Poutsiaka, D D; Mahoney, I J; McDermott, L A; Stern, L L; Thorpe, C M; Kane, A V; Baez-Giangreco, C; McKinney, J; Davidson, L E; Leyva, R; Goldin, B; Snydman, D R

    2017-05-01

    To develop a novel validated method for the isolation of Bifidobacterium animalis ssp. lactis BB-12 (BB-12) from faecal specimens and apply it to studies of BB-12 and Lactobacillus rhamnosus GG (LGG) recovered from the healthy human gastrointestinal (GI) tract. A novel method for isolating and enumerating BB-12 was developed based on its morphologic features of growth on tetracycline-containing agar. The method identified BB-12 correctly from spiked stool close to 100% of the time as validated by PCR confirmation of identity, and resulted in 97-104% recovery of BB-12. The method was then applied in a study of the recovery of BB-12 and LGG from the GI tract of healthy humans consuming ProNutrients ® Probiotic powder sachet containing BB-12 and LGG. Viable BB-12 and LGG were recovered from stool after 21 days of probiotic ingestion compared to baseline. In contrast, no organisms were recovered 21 days after baseline in the nonsupplemented control group. We demonstrated recovery of viable BB-12, using a validated novel method specific for the isolation of BB-12, and LGG from the GI tract of healthy humans who consumed the probiotic supplement. This method will enable more detailed and specific studies of BB-12 in probiotic supplements, including when in combination with LGG. © 2017 The Society for Applied Microbiology.

  8. Bifidobacterium--friend or foe? A case of urinary tract infection with Bifidobacterium species.

    Science.gov (United States)

    Pathak, Poonam; Trilligan, Cheryl; Rapose, Alwyn

    2014-09-24

    Bifidobacterium-a commensal of the human intestine is considered non-pathogenic and has been advocated as a probiotic due to its potential beneficial effects. However, there have been case reports implicating bifidobacteria as pathogenic agents in a variety of different infectious conditions. We discuss here one such case of a complicated urinary tract infection associated with Bifidobacterium spp. 2014 BMJ Publishing Group Ltd.

  9. Comparison of the acidifying activity of Lactococcus lactis subsp. lactis strains isolated from goat's milk and Valdeteja cheese.

    Science.gov (United States)

    Alonso-Calleja, C; Carballo, J; Capita, R; Bernardo, A; García-López, M L

    2002-01-01

    This work was carried out to study the acid production by Lactococcus lactis subsp. lactis strains isolated from goat's milk and goat cheese (Valdeteja variety) in order to select a suitable starter culture for industrial goat cheese manufacturing. The titrable acidity of 45 Lactococcus lactis subsp. lactis strains isolated from a home-made batch of Valdeteja cheese with excellent sensory characteristics was measured over a period of 18 h. The strains were divided into two groups depending on the acid production rate: 20 fast acid producer (F) strains and 25 slow acid producer (S) strains. The kinetic parameters (lag phase, maximum acid production rate and value of upper asymptote curve) of the acid production curves for F and S strains were significantly (P titrable acidity of F and S strains were observed after the second hour of incubation. An F strain acetoin producer (Lactococcus lactis subsp. lactis 470Ch2) was selected as autochthonous starter culture for industrial Valdeteja goat cheese manufacturing.

  10. Estudo dos parâmetros da ultrafiltração de permeado de soro de queijo fermentado por Lactococcus lactis subsp. lactis Ultrafiltration conditions of whey permeate fermented by Lactococcus lactis subsp. lactis

    Directory of Open Access Journals (Sweden)

    Viviane BRONSTEIN

    1998-04-01

    Full Text Available Permeado de soro doce, suplementado com extrato de levedura e peptona, foi utilizado como meio de crescimento para Lactococcus lactis subsp. lactis. No final da fase exponencial de crescimento, o meio de cultura fermentado foi submetido a uma ultrafiltração com o objetivo de concentrar o microrganismo. Foram realizados 6 processamentos diferentes, nos quais variou-se as condições iniciais da ultrafiltração, tendo sido avaliados os seguintes parâmetros: porosidade da membrana, pH e número de células viáveis no permeado e no retentado, a fim de ser estudado a influência de cada parâmetro na taxa de permeação da ultrafiltração. As membranas utilizadas foram eficazes como meio de barragem para o microrganismo Lactococcus lactis subsp. lactis, ficando o retentado com uma média celular de 10(8 ufc/ml e o permeado com uma média celular de 10² ufc/ml. Membranas de diferentes porosidades tiveram taxas de fluxo semelhantes. O aumento da concentração celular provocou a diminuição do fluxo. O pH também influenciou a taxa de permeação, havendo um aumento do fluxo quando foi utilizado um pH inicial mais alto.Cheese whey permeate supplemented with yeast extract and peptone was used as a growth medium for the bacteria Lactococcus lactis subsp. lactis. At the end of the exponential growth phase, the fermented growth medium was ultrafiltered to concentrate the microorganism and to evaluate the effect of the membrane porosity, inicial UF pH and cellular concentration in permeation rate during the ultrafiltration process. The membranes used were efficient as a mean of a barrage for the Lactococcus lactis subsp. lactis. On average, the cellular concentrations were 10(8 CFU/mL and 10² CFU/mL for retentate and permeate, respectively. Membranes of different porosities had very similar flux rates. Better flow rates were obtained with inicial UF pH 6,5 and with the minors micrrorganism concentration.

  11. Production of a Functional Frozen Yogurt Fortified with Bifidobacterium spp.

    OpenAIRE

    Abdelazez, Amro; Muhammad, Zafarullah; Zhang, Qiu-Xue; Zhu, Zong-Tao; Abdelmotaal, Heba; Sami, Rokayya; Meng, Xiang-Chen

    2017-01-01

    Frozen dairy products have characteristics of both yogurt and ice cream and could be the persuasive carriers of probiotics. Functions of the frozen yogurt containing viable bifidobacterial cells are recognized and favored by the people of all ages. We developed a kind of yogurt supplemented by Bifidobacterium species. Firstly, five strains of Bifidobacterium spp. (Bifidobacterium bifidum ATCC 11547, Bifidobacterium longum ATCC 11549, Bifidobacterium infantis ATCC 11551, Bifidobacterium adoles...

  12. Detection and characterization of bacteriocin-producing Lactococcus lactis strains Detecção e caracterização de Lactococcus lactis produtores de bacteriocinas

    Directory of Open Access Journals (Sweden)

    Izildinha Moreno

    1999-04-01

    Full Text Available One hundred sixty seven strains of Lactococcus lactis were screened for bacteriocin production by well diffusion assay of GM17 agar. Fourteen (8.4% produced antimicrobial activity other than organic acids, bacteriophages or hydrogen peroxide. The frequency of bacteriocin production ranged from 2% in L. lactis subsp. cremoris up to 12% in L. lactis subsp. lactis. Antimicrobial activities were not observed in any strain of L. lactis subsp. lactis var. diacetylactis. Among thirteen bacteriocin-producing strains and two nisin-producing strains (L. lactis subsp. lactis ATCC 11454 and L. lactis subsp. lactis CNRZ 150, eight (53% were characterized as lactose-positive (Lac+ and proteinase-negative (Prt-. The bacteriocin-producing cultures were also characterized on the basis of plasmid content. All strains had 2 to 7 plasmids with molecular weights varying from 0.5 to 28.1 Mdal. Four strains (ITAL 435, ITAL 436, ITAL 437 and ITAL 438 showed identical profiles and the other were quite distinct.Um total de 167 linhagens de L. lactis foi selecionado para os testes de produção de bacteriocinas pelo método de difusão em poços em agar GM17. Desse total, 14 (8.4% produziram substâncias inibidoras que não foram associadas com ácidos orgânicos, peróxido de hidrogênio e bacteriófagos. A frequência de produção de bacteriocinas variou de 2% em L. lactis subsp. cremoris a 12% em L. lactis subsp. lactis. Nenhuma das linhagens de L. lactis subsp. lactis var. diacetylactis produziu substâncias inibidoras. De 13 linhagens produtoras de bacteriocinas e duas de nisina (L. lactis subsp. lactis ATCC 11454 e L. lactis subsp. lactis CNRZ 150, 8 (53% foram caracterizadas como lactose-positivas (Lac+ e proteinase-negativas (Prt-. As linhagens produtoras de bacteriocinas também foram caracterizadas no seu conteúdo de plasmídios. Elas apresentaram de 2 a 7 plasmídios, com pesos moleculares aproximados de 0.5 a 28.1 Mdal. Quatro linhagens (ITAL 435, ITAL 436

  13. Characterization of a Wild, Novel Nisin A-Producing Lactococcus Strain with an L. lactis subsp. cremoris Genotype and an L. lactis subsp. lactis Phenotype, Isolated from Greek Raw Milk

    Science.gov (United States)

    Parapouli, Maria; Delbès-Paus, Céline; Kakouri, Athanasia; Koukkou, Anna-Irini; Montel, Marie-Christine

    2013-01-01

    Several molecular taxonomic studies have revealed that many natural (wild) Lactococcus lactis strains of dairy origin which are phenotypically representative of the L. lactis subspecies lactis cluster genotypically within subspecies cremoris and vice versa. Recently, we isolated two wild nisin-producing (Nis+) L. lactis strains, M78 and M104, of the lactis phenotype from Greek raw milk (J. Samelis, A. Lianou, A. Kakouri, C. Delbès, I. Rogelj, B. B. Matijašic, and M. C. Montel, J. Food Prot. 72:783–790, 2009); strain M78 possess a novel nisin A sequence (GenBank accession number HM219853). In this study, the actual subspecies identity of M78 and M104 isolates was elucidated, using 16S rRNA and acmA (encoding lactococcal N-acetylmuramidase) gene and histidine biosynthesis operon polymorphisms and 16S rRNA and ldh (encoding lactate dehydrogenase) gene phylogenies. Except the acmA gene analysis, molecular tools revealed that isolates M78 and M104 clustered with strains of the cremoris genotype, including the LMG 6897T strain, while they were distant from strains of the lactis genotype, including the LMG 6890T strain. The two wild isolates had identical repetitive sequence-based PCR (rep-PCR), randomly amplified polymorphic DNA (RAPD), plasmid, and whole-cell protein profiles and shared high 16S rRNA (99.9%) and ldh (100%) gene sequence homologies. In contrast, they exhibited identical sugar fermentation and enzymatic patterns which were similar to those of the subspecies lactis LMG 6890T strain. To our knowledge, this is the first complete identification report on a wild L. lactis subsp. cremoris genotype of the lactis phenotype which is capable of nisin A production and, thus, has strong potential for use as a novel dairy starter and/or protective culture. PMID:23542625

  14. Coculture of Bifidobacterium longum and Bifidobacterium breve alters their protein expression profiles and enzymatic activities.

    Science.gov (United States)

    Ruiz, Lorena; Sánchez, Borja; de Los Reyes-Gavilán, Clara G; Gueimonde, Miguel; Margolles, Abelardo

    2009-07-31

    Some strains of the genus Bifidobacterium are probiotic bacteria commonly added to functional dairy products. The influence of coculturing Bifidobacterium longum NCIMB8809 and Bifidobacterium breve NCIMB8807 on their physiology was studied. 2DE separation of protein extracts, coupled to MS protein analysis allowed the identification of 16 proteins whose expression drastically changed when cells were grown in compartmentalized coculture, compared to monoculture. These included ribosomal proteins and proteins involved in carbohydrate metabolism, gene regulation, cell envelope biogenesis and transport processes. Significant changes in some glycoside-hydrolysing activities (beta-d-xylopyranosidase, alpha-l-arabinofuranosidase and beta-d-glucopyranosidase) were also detected. Furthermore, qRT-PCR experiments using as targets the B. breve genes clgR (transcriptional regulator) clpP1, clpP2 and clpC (chaperone- and protease-encoding genes positively regulated by clgR) supported the proteomic results, the four genes displaying a higher expression level in coculture. This study provides new insights to understand the communication among Bifidobacterium species.

  15. Engineering of sugar metabolism in Lactococcus lactis

    NARCIS (Netherlands)

    Pool, Weia Arianne

    2008-01-01

    Short English Summary Lactococcus lactis is a lactic acid bacterium used in the dairy industry. This thesis decribes the genetic engineering performed on the sugar metabolism of L. lactis. Besides our fundamental interest for sugar metabolism and its regulation in L. lactis, this project had the

  16. Purification and partial characterization of bacteriocin produced by Lactococcus lactis ssp. lactis LL171.

    Science.gov (United States)

    Kumari, Archana; Akkoç, Nefise; Akçelik, Mustafa

    2012-04-01

    Lactic acid bacteria (LAB) are possessing ability to synthesize antimicrobial compounds (like bacteriocin) during their growth. In this regard, novel bacteriocin compound secreting capability of LAB isolated from Tulum Cheese in Turkey was demonstrated. The synthesized bacteriocin was purified by ammonium sulphate precipitation, dialysis and gel filtration. The molecular weight (≈3.4 kDa) of obtained bacteriocin was confirmed by SDS-PAGE, which revealed single peptide band. Molecular identification of LAB strain isolated from Tulum Cheese was conducted using 16S rDNA gene sequencing as Lactococcus lactis ssp. lactis LL171. The amino acid sequences (KKIDTRTGKTMEKTEKKIELSLKNMKTAT) of the bacteriocin from Lactococcus lactis ssp. lactis LL171 was found unique and novel than reported bacteriocins. Further, the bacteriocin was possessed the thermostable property and active at wide range of pH values from 1 to 11. Thus, bacteriocin reported in this study has the potential applications property as food preservative agent.

  17. Bifidobacterium aquikefiri sp. nov., isolated from water kefir.

    Science.gov (United States)

    Laureys, David; Cnockaert, Margo; De Vuyst, Luc; Vandamme, Peter

    2016-03-01

    A novel Bifidobacterium , strain LMG 28769 T , was isolated from a household water kefir fermentation process. Cells were Gram-stain-positive, non-motile, non-spore-forming, catalase-negative, oxidase-negative and facultatively anaerobic short rods. Analysis of its 16S rRNA gene sequence revealed Bifidobacterium crudilactis and Bifidobacterium psychraerophilum (97.4 and 97.1 % similarity towards the respective type strain sequences) as nearest phylogenetic neighbours. Its assignment to the genus Bifidobacterium was confirmed by the presence of fructose 6-phosphate phosphoketolase activity. Analysis of the hsp60 gene sequence revealed very low similarity with nucleotide sequences in the NCBI nucleotide database. The genotypic and phenotypic analyses allowed the differentiation of strain LMG 28769 T from all recognized Bifidobacterium species. Strain LMG 28769 T ( = CCUG 67145 T  = R 54638 T ) therefore represents a novel species, for which the name Bifidobacterium aquikefiri sp. nov. is proposed.

  18. Draft Genome Sequence of the Putrescine-Producing Strain Lactococcus lactis subsp. lactis 1AA59

    Science.gov (United States)

    del Rio, Beatriz; Linares, Daniel M.; Fernandez, María; Mayo, Baltasar; Martín, M. Cruz

    2015-01-01

    We report here the 2,576,542-bp genome annotated draft assembly sequence of Lactococcus lactis subsp. lactis 1AA59. This strain—isolated from a traditional cheese—produces putrescine, one of the most frequently biogenic amines found in dairy products. PMID:26089428

  19. Bacteriocinogenic Lactococcus lactis subsp. lactis DF04Mi isolated from goat milk: characterization of the bacteriocin

    Directory of Open Access Journals (Sweden)

    Danielle N. Furtado

    2014-12-01

    Full Text Available Lactic acid bacteria capable of producing bacteriocins and presenting probiotic potential open innovative technological applications in the dairy industry. In this study, a bacteriocinogenic strain (Lactococcus lactis subsp. lactis DF4Mi was isolated from goat milk, and studied for its antimicrobial activity. The bacteriocin presented a broad spectrum of activity, was sensitive to proteolytic enzymes, resistant to heat and pH extremes, and not affected by the presence of SDS, Tween 20, Tween 80, EDTA or NaCl. Bacteriocin production was dependent on the components of the culture media, especially nitrogen source and salts. When tested by PCR, the bacteriocin gene presented 100% homology to nisin Z gene. These properties indicate that this L. lactis subsp. lactis DF4Mi can be used for enhancement of dairy foods safety and quality.

  20. Bacteriocinogenic Lactococcus lactis subsp. lactis DF04Mi isolated from goat milk: Characterization of the bacteriocin

    Science.gov (United States)

    Furtado, Danielle N.; Todorov, Svetoslav D.; Landgraf, Mariza; Destro, Maria T.; Franco, Bernadette D.G.M.

    2014-01-01

    Lactic acid bacteria capable of producing bacteriocins and presenting probiotic potential open innovative technological applications in the dairy industry. In this study, a bacteriocinogenic strain (Lactococcus lactis subsp. lactis DF4Mi) was isolated from goat milk, and studied for its antimicrobial activity. The bacteriocin presented a broad spectrum of activity, was sensitive to proteolytic enzymes, resistant to heat and pH extremes, and not affected by the presence of SDS, Tween 20, Tween 80, EDTA or NaCl. Bacteriocin production was dependent on the components of the culture media, especially nitrogen source and salts. When tested by PCR, the bacteriocin gene presented 100% homology to nisin Z gene. These properties indicate that this L. lactis subsp. lactis DF4Mi can be used for enhancement of dairy foods safety and quality. PMID:25763065

  1. Introduction of peptidase genes from Lactobacillus delbrueckii subsp. lactis into Lactococcus lactis and controlled expression

    NARCIS (Netherlands)

    Wegmann, U.; Klein, J.R.; Drumm, I.; Kuipers, O.P.; Henrich, B.

    Peptidases PepI, PepL, PepW, and PepG from Lactobacillus delbrueckii subsp, lactis, which have no counterparts in Lactococcus lactis, and peptidase PepQ were examined to determine their potential to confer new peptidolytic properties to lactococci, Controllable expression of the corresponding genes

  2. Liposome-enhanced transformation of Streptococcus lactis and plasmid transfer by intergeneric protoplast fusion of Streptococcus lactis and Bacillus subtilis

    NARCIS (Netherlands)

    Vossen, Jos M.B.M. van der; Kok, Jan; Lelie, Daniel van der; Venema, Gerhardus

    An efficient protoplast transformation system and a procedure of plasmid transfer by means of protoplast fusion is described for Streptococcus lactis. Protoplasts of S. lactis IL1403 and S. lactis MG1363 were transformed by pGK12 [2.9 MDa erythromycin resistance (Emr)] with an efficiency of 3 × 10^5

  3. Reduction of salivary mutans streptococci in orthodontic patients during daily consumption of yoghurt containing probiotic bacteria

    DEFF Research Database (Denmark)

    Cildir, Sule Kavaloglu; Germec, Derya; Sandalli, Nuket

    2009-01-01

    Previous studies have suggested that probiotic supplements in dairy products may affect the oral microbial ecology, but the effect in orthodontic patients has not previously been reported. The aim of the present study was to examine whether short-term consumption of fruit yogurt containing....... During periods 2 and 4 (2 weeks each), the subjects ingested 200 g fruit yogurt containing Bifidobacterium animalis subsp. lactis DN-173010 (2 x 10(8) colony forming units/g) once daily or a control yogurt without viable bacteria. Periods 1 and 3 were run-in and wash-out periods of 1 and 6 weeks......, respectively. Salivary mutans streptococci and lactobacilli were enumerated with chair-side kits before and after the yogurt consumption periods. Pre- and post-treatment values within each regimen were compared with a two-tailed marginal homogeneity test for categorical data. A statistically significant...

  4. Inhibitory Effect of Lactococcus lactis HY 449 on Cariogenic Biofilm.

    Science.gov (United States)

    Kim, Young-Jae; Lee, Sung-Hoon

    2016-11-28

    Dental caries is caused by cariogenic biofilm, an oral biofilm including Streptococcus mutans . Recently, the prevention of dental caries using various probiotics has been attempted. Lactococcus lactis HY 449 is a probiotic bacterium. The aim of this study was to investigate the effect of L. lactis HY 449 on cariogenic biofilm and to analyze its inhibitory mechanisms. Cariogenic biofilm was formed in the presence or absence of L. lactis HY 449 and L. lactis ATCC 19435, and analyzed with a confocal laser microscope. The formation of cariogenic biofilm was reduced in cultures spiked with both L. lactis strains, and L. lactis HY 449 exhibited more inhibitory effects than L. lactis ATCC 19435. In order to analyze and to compare the inhibitory mechanisms, the antibacterial activity of the spent culture medium from both L. lactis strains against S. mutans was investigated, and the expression of glucosyltransferases ( gtfs ) of S. mutans was then analyzed by real-time RT-PCR. In addition, the sucrose fermentation ability of both L. lactis strains was examined. Both L. lactis strains showed antibacterial activity and inhibited the expression of gtfs , and the difference between both strains did not show. In the case of sucrose-fermenting ability, L. lactis HY 449 fermented sucrose but L. lactis ATCC 19435 did not. L. lactis HY 449 inhibited the uptake of sucrose and the gtfs expression of S. mutans , whereby the development of cariogenic biofilm may be inhibited. In conclusion, L. lactis HY 449 may be a useful probiotic for the prevention of dental caries.

  5. Effect of Potential Probiotic Lactococcus lactis Subsp. lactis on Growth Performance, Intestinal Microbiota, Digestive Enzyme Activities, and Disease Resistance of Litopenaeus vannamei.

    Science.gov (United States)

    Adel, Milad; El-Sayed, Abdel-Fattah M; Yeganeh, Sakineh; Dadar, Maryam; Giri, Sib Sankar

    2017-06-01

    The aims of this study were to evaluate the effects of Lactococcus lactis subsp. lactis on the growth, intestinal microbiota, digestive enzyme activity, and disease resistance of Litopenaeus vannamei. Diets containing four different concentrations of L. lactis (0 [basal diet], 10 6 , 10 7 , and 10 8  CFU g -1 ) were fed to white shrimps L. vannamei (average weight 5.89 ± 0.36 g) for 8 weeks. At the end of the feeding trial, shrimps were immersed in Caspian Seawater (10.8 ppt) contaminated with 10 6  CFU ml -1 pathogenic V. anguillarum for 2 h. Results revealed that growth rate, survival, and body protein level were increased with dietary supplementation of L. lactis. The activities of digestive enzymes (cellulose, lipase, amylase, and protease) were significantly higher in the groups fed with diets containing 10 7 or 10 8  CFU g -1 L. lactis than those in the control. The Lactobacillus and Bacillus counts were higher (P lactis-supplemented diets. In addition, higher level of L. lactis supplementation decreased the Vibrio counts. Moreover, L. vannamei fed diet supplemented with 10 8  CFU g -1 of L. lactis exhibited significantly the highest hematocyte count and post-challenge survival rate (79.2 %). Collectively, these results suggest that dietary supplementation of L. lactis subsp. lactis at 10 8  CFU g -1 can promote growth performance, digestive enzyme activity, and disease resistance of L. vannamei.

  6. Production of a Functional Frozen Yogurt Fortified with Bifidobacterium spp.

    Science.gov (United States)

    Abdelazez, Amro; Muhammad, Zafarullah; Zhang, Qiu-Xue; Zhu, Zong-Tao; Abdelmotaal, Heba; Sami, Rokayya; Meng, Xiang-Chen

    2017-01-01

    Frozen dairy products have characteristics of both yogurt and ice cream and could be the persuasive carriers of probiotics. Functions of the frozen yogurt containing viable bifidobacterial cells are recognized and favored by the people of all ages. We developed a kind of yogurt supplemented by Bifidobacterium species. Firstly, five strains of Bifidobacterium spp. ( Bifidobacterium bifidum ATCC 11547, Bifidobacterium longum ATCC 11549, Bifidobacterium infantis ATCC 11551, Bifidobacterium adolescentis ATCC 11550, and Bifidobacterium breve ATCC 11548) were evaluated based on the feasibility criteria of probiotics, comprising acid production, bile tolerance, and adhesion to epithelial cells. Formerly, we combined the optimum strains with yogurt culture ( Lactobacillus delbrueckii subsp. bulgaricus EMCC 11102 and Streptococcus salivarius subsp. thermophilus EMCC 11044) for producing frozen yogurt. Finally, physiochemical properties and sensory evaluation of the frozen yogurt were investigated during storage of 60 days at -18°C. Results directed that Bifidobacterium adolescentis ATCC 11550 and Bifidobacterium infantis ATCC 11551 could be utilized with yogurt culture for producing frozen yogurt. Moreover, the frozen yogurt fermented by two bifidobacterial strains and yogurt culture gained the high evaluation in the physiochemical properties and sensory evaluation. In summary, our results revealed that there was no significant difference between frozen yogurt fermented by Bifidobacterium spp. and yogurt culture and that fermented by yogurt culture only.

  7. Study of physiological properties of some probiotics in multiple cultures with mesophilic lactic acid bacteria by Flora Danica Ch. Hansen commercial starter

    OpenAIRE

    DANIELA PARASCHIV; AIDA VASILE; MADALINA CONSTANTIN; ALEXANDRU CIOBANU; GABRIELA BAHRIM

    2011-01-01

    The aim of this study was to establish the growth ability and stability of probiotic strains Lactobacillus acidophilus (commercial code La-5®), Lactobacillus casei ssp. paracasei (commercial code L. casei 431®) and Bifidobacterium bifidus (commercial code BB-12®) in multiple cultures with mesophilic lactic bacteria, Lactococcus lactis ssp. cremoris, Lactococcus lactis ssp. lactis, Lactococcus lactis ssp. diacetylactis and Leuconostoc mesenteroides spp. cremoris, as Flora Danica Chr. Hansen co...

  8. Study Protocol Effect of the consumption of a fermented dairy product containing Bifidobacterium lactis DN-173 010 on constipation in childhood: a multicentre randomised controlled trial (NTRTC: 1571)

    NARCIS (Netherlands)

    Tabbers, Merit M.; Chmielewska, Ania; Roseboom, Maaike G.; Boudet, Claire; Perrin, Catherine; Szajewska, Hania; Benninga, Marc A.

    2009-01-01

    ABSTRACT: BACKGROUND: Constipation is a frustrating symptom affecting 3% of children worldwide. Randomised controlled trials show that both polyethylene glycol and lactulose are effective in increasing defecation frequency in children with constipation. However, in 30-50%, these children reported

  9. Consumption of Bifidobacterium animalis subsp. lactis BB-12 in yogurt reduced expression of TLR-2 on peripheral blood-derived monocytes and pro-inflammatory cytokine secretion in young adults.

    Science.gov (United States)

    Meng, Huicui; Ba, Zhaoyong; Lee, Yujin; Peng, Jiayu; Lin, Junli; Fleming, Jennifer A; Furumoto, Emily J; Roberts, Robert F; Kris-Etherton, Penny M; Rogers, Connie J

    2017-03-01

    Probiotic bacteria modulate immune parameters and inflammatory outcomes. Emerging evidence demonstrates that the matrix used to deliver probiotics may influence the efficacy of probiotic interventions in vivo. The aims of the current study were to evaluate (1) the effect of one species, Bifidobacterium animalis subsp. lactis BB-12 at a dose of log10 ± 0.5 CFUs/day on immune responses in a randomized, partially blinded, 4-period crossover, free-living study, and (2) whether the immune response to BB-12 differed depending on the delivery matrix. Healthy adults (n = 30) aged 18-40 years were recruited and received four treatments in a random order: (A) yogurt smoothie alone; smoothie with BB-12 added (B) before or (C) after yogurt fermentation, or (D) BB-12 given in capsule form. At baseline and after each 4-week treatment, peripheral blood mononuclear cells (PBMCs) were isolated, and functional and phenotypic marker expression was assessed. BB-12 interacted with peripheral myeloid cells via Toll-like receptor 2 (TLR-2). The percentage of CD14 + HLA-DR + cells in peripheral blood was increased in male participants by all yogurt-containing treatments compared to baseline (p = 0.0356). Participants who consumed yogurt smoothie with BB-12 added post-fermentation had significantly lower expression of TLR-2 on CD14 + HLA-DR + cells (p = 0.0186) and reduction in TNF-α secretion from BB-12- (p = 0.0490) or LPS-stimulated (p = 0.0387) PBMCs compared to baseline. These findings not only demonstrate a potential anti-inflammatory effect of BB-12 in healthy adults, but also indicate that the delivery matrix influences the immunomodulatory properties of BB-12.

  10. Transcriptome analysis and related databases of Lactococcus lactis

    NARCIS (Netherlands)

    Kuipers, Oscar P.; Jong, Anne de; Baerends, Richard J.S.; Hijum, Sacha A.F.T. van; Zomer, Aldert L.; Karsens, Harma A.; Hengst, Chris D. den; Kramer, Naomi E.; Buist, Girbe; Kok, Jan

    Several complete genome sequences of Lactococcus lactis and their annotations will become available in the near future, next to the already published genome sequence of L. lactis ssp. lactis IL1403. This will allow intraspecies comparative genomics studies as well as functional genomics studies

  11. Production of a Functional Frozen Yogurt Fortified with Bifidobacterium spp.

    Science.gov (United States)

    Muhammad, Zafarullah; Zhang, Qiu-Xue; Zhu, Zong-Tao

    2017-01-01

    Frozen dairy products have characteristics of both yogurt and ice cream and could be the persuasive carriers of probiotics. Functions of the frozen yogurt containing viable bifidobacterial cells are recognized and favored by the people of all ages. We developed a kind of yogurt supplemented by Bifidobacterium species. Firstly, five strains of Bifidobacterium spp. (Bifidobacterium bifidum ATCC 11547, Bifidobacterium longum ATCC 11549, Bifidobacterium infantis ATCC 11551, Bifidobacterium adolescentis ATCC 11550, and Bifidobacterium breve ATCC 11548) were evaluated based on the feasibility criteria of probiotics, comprising acid production, bile tolerance, and adhesion to epithelial cells. Formerly, we combined the optimum strains with yogurt culture (Lactobacillus delbrueckii subsp. bulgaricus EMCC 11102 and Streptococcus salivarius subsp. thermophilus EMCC 11044) for producing frozen yogurt. Finally, physiochemical properties and sensory evaluation of the frozen yogurt were investigated during storage of 60 days at −18°C. Results directed that Bifidobacterium adolescentis ATCC 11550 and Bifidobacterium infantis ATCC 11551 could be utilized with yogurt culture for producing frozen yogurt. Moreover, the frozen yogurt fermented by two bifidobacterial strains and yogurt culture gained the high evaluation in the physiochemical properties and sensory evaluation. In summary, our results revealed that there was no significant difference between frozen yogurt fermented by Bifidobacterium spp. and yogurt culture and that fermented by yogurt culture only. PMID:28691028

  12. Production of a Functional Frozen Yogurt Fortified with Bifidobacterium spp.

    Directory of Open Access Journals (Sweden)

    Amro Abdelazez

    2017-01-01

    Full Text Available Frozen dairy products have characteristics of both yogurt and ice cream and could be the persuasive carriers of probiotics. Functions of the frozen yogurt containing viable bifidobacterial cells are recognized and favored by the people of all ages. We developed a kind of yogurt supplemented by Bifidobacterium species. Firstly, five strains of Bifidobacterium spp. (Bifidobacterium bifidum ATCC 11547, Bifidobacterium longum ATCC 11549, Bifidobacterium infantis ATCC 11551, Bifidobacterium adolescentis ATCC 11550, and Bifidobacterium breve ATCC 11548 were evaluated based on the feasibility criteria of probiotics, comprising acid production, bile tolerance, and adhesion to epithelial cells. Formerly, we combined the optimum strains with yogurt culture (Lactobacillus delbrueckii subsp. bulgaricus EMCC 11102 and Streptococcus salivarius subsp. thermophilus EMCC 11044 for producing frozen yogurt. Finally, physiochemical properties and sensory evaluation of the frozen yogurt were investigated during storage of 60 days at −18°C. Results directed that Bifidobacterium adolescentis ATCC 11550 and Bifidobacterium infantis ATCC 11551 could be utilized with yogurt culture for producing frozen yogurt. Moreover, the frozen yogurt fermented by two bifidobacterial strains and yogurt culture gained the high evaluation in the physiochemical properties and sensory evaluation. In summary, our results revealed that there was no significant difference between frozen yogurt fermented by Bifidobacterium spp. and yogurt culture and that fermented by yogurt culture only.

  13. Detection and viability of Lactococcus lactis throughout cheese ripening.

    Directory of Open Access Journals (Sweden)

    Marianna Ruggirello

    Full Text Available Recent evidences highlighted the presence of Lactococcus lactis during late cheese ripening. For this reason, the role of this microorganism, well known as dairy starter, should be reconsidered throughout cheese manufacturing and ripening. Thus, the main objective of this study was to develop a RT-qPCR protocol for the detection, quantification and determination of the viability of L. lactis in ripened cheese samples by direct analysis of microbial nucleic acids. Standard curves were constructed for the specific quantification of L. lactis in cheese matrices and good results in terms of selectivity, correlation coefficient and efficiency were obtained. Thirty-three ripened cheeses were analyzed and, on the basis of RNA analysis, twelve samples showed 106 to 108 CFU of L. lactis per gram of product, thirteen from 103 to 105 CFU/g, and in eight cheeses, L. lactis was not detected. Traditional plating on M17 medium led to loads ranging from 105 to 109 CFU/g, including the cheese samples where no L. lactis was found by RT-qPCR. From these cheeses, none of the colonies isolated on M17 medium was identified as L. lactis species. These data could be interpreted as a lack of selectivity of M17 medium where colony growth is not always related to lactococcal species. At the same time, the absence or low abundance of L. lactis isolates on M17 medium from cheese where L. lactis was detected by RT-qPCR support the hypothesis that L. lactis starter populations are mainly present in viable but not culturable state during ripening and, for this reason, culture-dependent methods have to be supplemented with direct analysis of cheese.

  14. Detection and Viability of Lactococcus lactis throughout Cheese Ripening

    Science.gov (United States)

    Cocolin, Luca

    2014-01-01

    Recent evidences highlighted the presence of Lactococcus lactis during late cheese ripening. For this reason, the role of this microorganism, well known as dairy starter, should be reconsidered throughout cheese manufacturing and ripening. Thus, the main objective of this study was to develop a RT-qPCR protocol for the detection, quantification and determination of the viability of L. lactis in ripened cheese samples by direct analysis of microbial nucleic acids. Standard curves were constructed for the specific quantification of L. lactis in cheese matrices and good results in terms of selectivity, correlation coefficient and efficiency were obtained. Thirty-three ripened cheeses were analyzed and, on the basis of RNA analysis, twelve samples showed 106 to 108 CFU of L. lactis per gram of product, thirteen from 103 to 105 CFU/g, and in eight cheeses, L. lactis was not detected. Traditional plating on M17 medium led to loads ranging from 105 to 109 CFU/g, including the cheese samples where no L. lactis was found by RT-qPCR. From these cheeses, none of the colonies isolated on M17 medium was identified as L. lactis species. These data could be interpreted as a lack of selectivity of M17 medium where colony growth is not always related to lactococcal species. At the same time, the absence or low abundance of L. lactis isolates on M17 medium from cheese where L. lactis was detected by RT-qPCR support the hypothesis that L. lactis starter populations are mainly present in viable but not culturable state during ripening and, for this reason, culture-dependent methods have to be supplemented with direct analysis of cheese. PMID:25503474

  15. Characterization of a cadmium resistance Lactococcus lactis subsp. lactis strain by antioxidant assays and proteome profiles methods.

    Science.gov (United States)

    Sheng, Yao; Yang, Xuan; Lian, Yuanyuan; Zhang, Boyang; He, Xiaoyun; Xu, Wentao; Huang, Kunlun

    2016-09-01

    Heavy metal contamination poses a major threat to the environment and human health for their potential toxicity and non-biodegradable properties. At present, some probiotics bacteria are reported to have great potential to eliminate heavy metals from food and water. In this study, resistance properties of a newly isolated Lactococcus lactis subsp. lactis for cadmium were studied by antioxidant assays and proteomics analysis. Antioxidant capacity of this strain was significantly activated under cadmium stress indicated by Fenton reaction, DPPH assay, SOD assay and GSH assay. Intracellular antioxidant enzyme systems, such as superoxide dismutase, glutathione reductase and catalase were suggested to play vital roles in the activated antioxidant capacity. The up-regulated cadA was associated with the activated P-type ATPases that plays an important role in cadmium resistance. Proteomics analysis identified 12 over-expressed proteins under 50mg/L cadmium stress and these proteins are abundant in oxidative stress response and energy metabolism regulation, which were considered as consequences as cadmium resistance of the strain. Thus, the probiotics Lactococcus lactis subsp. lactis may resist cadmium stress through antioxidant approach and enhanced energy metabolism. The food grade lactis strain may be applied in metal decontamination in environment and food/feed. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. [A comparison of the properties of bacteriocins formed by Lactococcus lactis subsp. lactis strains of diverse origin].

    Science.gov (United States)

    Stoianova, L G; Egorov, N S; Fedorova, G B; Katrukha, G S; Netrusov, A I

    2007-01-01

    Bacteriocins formed by four strains of Lactococcus lactis subsp. lactis have been studied and compared: 729 (a natural strain isolated from milk), 1605 (a mutant of strain 729), F-116 (a recombinant obtained by fusing of protoplasts of the two related strain 729 and 1605), and a nisin-forming strain obtained by adaptive selection at Moscow State University. Antimicrobial activity studies revealed differences between the strains in the effects on individual groups of microorganisms; the activities of the strains were also distinct from that of Nisaplin (a commercial preparation of the bacteriocin nisin). Methods for isolation and purification of bacteriocins have been developed, making it possible to obtain individual components of antibiotic complexes as chromatographically pure preparations. Bacteriocins formed by the strains of Lactococcus lactis subsp. lactis have been identified and differences in their biological and physicochemical properties, established. A novel potent broad-spectrum antibiotic substance distinct from nisin has been isolated from the recombinant strain F-116.

  17. Suitability of Lactococcus lactis subsp lactis ATCC 11454 as a protective culture for lightly preserved fish products

    DEFF Research Database (Denmark)

    Wessels, Stephen Wallace; Huss, Hans Henrik

    1996-01-01

    This study is part of strategy to control the human pathogen Listeria monocytogenes in lightly preserved fish products by using food-grade lactic acid bacteria. When the nisin-producing Lactococcus lactis subsp lactis ATCC 11454 was cultured in the same vessel as L-monocytogenes Scott A in brain......-heart infusion broth (BHI) at 30-degrees C, the pathogen declined from 5x10(5) to fewer than 5 cfu ml(-1) within 31 h. The effect was not due to lactic acid inhibition. Growth and nisin production by L- lactis ATCC 11454 were investigated under the conditions of temperature and salt used for light preservation...... and no detectable nisin. On slices of commercial cold-smoked salmon at 10-degrees C, no net propagation pf L-lactis ATCC 11454 could be detected within 21 days. However, when salmon slices were inoculated with L- mycocytogenes at 10(4) cfu g(-1) and a 300-fold excess of washed lactococcus cells, the pathogen...

  18. Evaluation of the probiotic properties of new Lactobacillus and Bifidobacterium strains and their in vitro effect.

    Science.gov (United States)

    Presti, I; D'Orazio, G; Labra, M; La Ferla, B; Mezzasalma, V; Bizzaro, G; Giardina, S; Michelotti, A; Tursi, F; Vassallo, M; Di Gennaro, P

    2015-07-01

    Probiotic ingestion is recommended as a preventive approach to maintain the balance of the intestinal microbiota and to enhance the human well-being. During the whole life of each individual, the gut microbiota composition could be altered by lifestyle, diet, antibiotic therapies and other stress conditions, which may lead to acute and chronic disorders. Hence, probiotics can be administered for the prevention or treatment of some disorders, including lactose malabsorption, acute diarrhoea, irritable bowel syndrome, necrotizing enterocolitis and mild forms of inflammatory bowel disease. The probiotic-mediated effect is an important issue that needs to be addressed in relation to strain-specific probiotic properties. In this work, the probiotic properties of new Lactobacillus and Bifidobacterium strains were screened, and their effects in vitro were evaluated. They were screened for probiotic properties by determining their tolerance to low pH and to bile salts, antibiotic sensitivity, antimicrobial activity and vitamin B8, B9 and B12 production, and by considering their ability to increase the antioxidant potential and to modulate the inflammatory status of systemic-miming cell lines in vitro. Three out of the examined strains presenting the most performant probiotic properties, as Lactobacillus plantarum PBS067, Lactobacillus rhamnosus PBS070 and Bifidobacterium animalis subsp. lactis PBSO75, were evaluated for their effects also on human intestinal HT-29 cell line. The obtained results support the possibility to move to another level of study, that is, the oral administration of these probiotical strains to patients with acute and chronic gut disorders, by in vivo experiments.

  19. Lactococcus lactis - a diploid bacterium

    DEFF Research Database (Denmark)

    Michelsen, Ole; Hansen, Flemming G.; Jensen, Peter Ruhdal

    the next division. Thus, the regions of the chromosome that are the last to be replicated are haploid even in fast-growing bacteria. In contrast to this general rule for bacteria, we found that Lactococcus lactis, a bacterium which has been exploited for thousands of years for the production of fermented...... milk products, is born with two complete non-replicating chromosomes. L. lactis therefore remain diploid throughout its entire life cycle....

  20. Dynamics of pyruvate metabolism in Lactococcus lactis

    DEFF Research Database (Denmark)

    Melchiorsen, Claus Rix; Jensen, Niels B.S.; Christensen, Bjarke

    2001-01-01

    The pyruvate metabolism in the lactic acid bacterium Lactococcus lactis was studied in anaerobic cultures under transient conditions. During growth of L. lactis in continuous culture at high dilution rate, homolactic product formation was observed, i.e., lactate was produced as the major end...... product. At a lower dilution rate, the pyruvate metabolism shifted towards mixed acid-product formation where formate, acetate, and ethanol were produced in addition to lactate. The regulation of the shift in pyruvate metabolism was investigated by monitoring the dynamic behavior of L. lactis...

  1. Expression of prophage-encoded endolysins contributes to autolysis of Lactococcus lactis

    NARCIS (Netherlands)

    Visweswaran, Ganesh Ram R.; Kurek, Dorota; Szeliga, Monika; Pastrana, Francisco Romero; Kuipers, Oscar P.; Kok, Jan; Buist, Girbe

    Analysis of autolysis of derivatives of Lactococcus lactis subsp. cremoris MG1363 and subsp. lactis IL1403, both lacking the major autolysin AcmA, showed that L. lactis IL1403 still lysed during growth while L. lactis MG1363 did not. Zymographic analysis revealed that a peptidoglycan hydrolase

  2. POTENTIAL OF Lactococcus lactis subsp. lactis MTCC 3041 AS A BIOPRESERVATIVE

    Directory of Open Access Journals (Sweden)

    Neha Sharma

    2013-10-01

    Full Text Available Lactic acid bacteria especially in developing countries can be exploited against frequently occurring spoilage organisms of fresh fruits and vegetables in addition to pathogens. Keeping in views this antagonism imparted by bacteria Lactococci, the present study was taken and effectiveness of bacteriocin of Lactococci was also studied in preservatives and enzymes. Lactic acid bacteria Lactococcus lactis subs. Lactis MTCC 3041 was used as bacteriocin producer strain. Isolation of most frequently occurring spoilage organisms from spoiled Mango and Kinnow was done by microbiological procedures and were identified by microscopic studies as Isolate 1 and Isolate 2. It has limited use in processed salted food as no zone of inhibition was observed at and above 5% NaCl (w/v.0.3% (w/v is the minimum concentration of KMS that provides stress to the microorganism for the production of bacteriocin. It is not suitable for food having sodium benzoate as preservative as with increase in concentration growth of Lactococcus lactis decreases. Presence of bacteriocin hinders the growth of the isolate 1 as fresh weight of the mycelium in test sample is 7.09% less than the control. Being non-pathogenic this organism can be safely used against spoilage organisms in addition to food borne pathogens.

  3. Heterologous Expression and Characterization of an N-Acetyl-beta-D-hexosaminidase from Lactococcus lactis ssp. lactis IL1403

    Czech Academy of Sciences Publication Activity Database

    Nguyen, A. H.; Nguyen, T.-H.; Křen, Vladimír; Eijsink, V. G. H.; Haltrich, D.; Peterbauer, C.

    2012-01-01

    Roč. 60, č. 12 (2012), s. 3275-3281 ISSN 0021-8561 R&D Projects: GA ČR(CZ) GAP207/11/0629 Keywords : N-acetyl-beta-D-hexosaminidase * Lactococcus lactis ssp lactis IL1403 * pNP-GlcNAc Subject RIV: CE - Biochemistry Impact factor: 2.906, year: 2012

  4. Lactococcus lactis subsp. lactis MA83 Suşunda Aktif Bir Faj Dirençlilik Sisteminin Genetik ve Biyokimyasal Doğası

    OpenAIRE

    Tükel, Çağla; Akçelik, Mustafa

    2003-01-01

    Lactococcus lactis subsp. lactis MA83 susunda fajlann adsorbsiyonu, bu bakteride 32.7 kb büyüklükteki plazmidin varlığında üretilen ekzopolisakkarit materyal tarafından engellendi. Kimyasal analizler sonucunda bu ekzopolisakkarit materyalin ana bileşenlerinin galaktoz, galaktozamin, ramnoz ve fosfat olduğu belirlendi. Ayrıca, L. lactis subsp. lactis MA83 susunda Øla2, Øp78, Ør4 ve Øp81 fajlannın almaç bölgelerinin protein yapıda olduğu saptandı.  

  5. The Comparition of the Efficacy of Two Different Probiotics in Rotavirus Gastroenteritis in Children

    Directory of Open Access Journals (Sweden)

    Özlem Erdoğan

    2012-01-01

    Full Text Available Objectives. The aim of the study is to compare the clinical effectiveness of the probiotics—Saccharomyces boulardii and Bifidobacterium lactis—in children who had been diagnosed with rotavirus gastroenteritis. Materials and methods. Seventy five patients aged between 5 months–5 years diagnosed as rotavirus gastroenteritis were included in the study. The patients diagnosed as rotavirus gastroenteritis by latex agglutination test in stool were divided into 3 groups of twenty-five patients each: First group was given oral rehydration therapy and rapid refeeding with a normal diet with Saccharomyces boulardii (spp. I-745, second group was given oral rehydration therapy and rapid refeeding with a normal diet with Bifidobacterium lactis (spp. B94, culture number:∘118529 and third group received only oral rehydration therapy and rapid refeeding with a normal diet. Results. The duration of diarrhea was shorter in the group given oral rehydration therapy and rapid refeeding with a normal diet with Bifidobacterium lactis and Saccharomyces boulardii than the group given only oral rehydration therapy and rapid refeeding with a normal diet. Conclusion. Bifidobacterium lactis has a complemental role in the treatment of rotavirus gatroenteritis and other probiotics may also have a beneficial effect in rotavirus gastroenteritis compared with the therapy included only oral rehydration therapy and rapid refeeding with a normal diet.

  6. Adaptation of Lactococcus lactis to its environment : a genomics approach

    NARCIS (Netherlands)

    Zomer, Albertus Lambert

    2007-01-01

    This thesis describes a number of strategies of Lactococcus lactis to adapt to its ever-changing environment. Although the complete genome sequence of L. lactis subspecies lactis IL1403, became available when this research was started, the genome sequence of the lactic acid bacterial paradigm, L.

  7. Retracted: Association of ACE I/D gene polymorphism with T2DN susceptibility and the risk of T2DM developing into T2DN in a Caucasian population.

    Science.gov (United States)

    Liu, Guohui; Zhou, Tian-Biao; Jiang, Zongpei; Zheng, Dongwen

    2015-03-01

    The association of the angiotensin-converting enzyme (ACE) insertion/deletion (I/D) gene polymorphism with type-2 diabetic nephropathy (T2DN) susceptibility and the risk of type-2 diabetes mellitus (T2DM) developing into T2DN in Caucasian populations is still controversial. A meta-analysis was performed to evaluate the association of ACE I/D gene polymorphism with T2DN susceptibility and the risk of T2DM developing into T2DN in Caucasian populations. A predefined literature search and selection of eligible relevant studies were performed to collect data from electronic databases. Sixteen articles were identified for the analysis of the association of ACE I/D gene polymorphism with T2DN susceptibility and the risk of T2DM developing into T2DN in Caucasian populations. ACE I/D gene polymorphism was not associated with T2DN susceptibility and the risk of patients with T2DM developing T2DN in Caucasian populations. Sensitivity analysis according to sample size of case (ACE I/D gene polymorphism was not associated with T2DN susceptibility and the risk of patients with T2DM developing T2DN in Caucasian populations. However, more studies should be performed in the future. © The Author(s) 2014.

  8. Effect of production conditions on the stability of a human bifidobacterial species Bifidobacterium longum in yogurt.

    Science.gov (United States)

    Abe, F; Tomita, S; Yaeshima, T; Iwatsuki, K

    2009-12-01

    Human bifidobacteria are more sensitive to external environmental factors than animal bifidobacteria, and it is difficult to ensure their stable survival in yogurt. The purpose of this investigation was to observe the survival of human bifidobacteria in yogurts produced under various production conditions. Frozen or lyophilized bifidobacteria starters containing Bifidobacterium longum BB536 originally isolated from an infant, and commercial lyophilized yogurt starters were used for yogurt preparation. After producing yogurts under various conditions, the survival of bifidobacteria in these yogurts over various storage periods was observed. Although there were some differences in bifidobacterial survival in yogurt between various production conditions, more than 1.0 x 10(7) CFU g(-1) of Bif. longum survived in yogurt after 35 days' storage at 5 degrees C. Lower fermentation temperature (37 degrees C) and inclusion of Lactococcus lactis in the starter significantly (P yogurt. In this investigation, the human bifidobacterial strain Bif. longum survived adequately in yogurt, although the fermentation temperature and starter composition affect bifidobacterial survival. This investigation indicates that stable probiotic yogurt using human bifidobacteria can be produced by choosing optimal production conditions.

  9. Short communication: Genotypic and phenotypic identification of environmental streptococci and association of Lactococcus lactis ssp. lactis with intramammary infections among different dairy farms.

    Science.gov (United States)

    Werner, B; Moroni, P; Gioia, G; Lavín-Alconero, L; Yousaf, A; Charter, M E; Carter, B Moslock; Bennett, J; Nydam, D V; Welcome, F; Schukken, Y H

    2014-11-01

    Lactococcus species are counted among a large and closely related group of environmental streptococci and streptococci-like bacteria that include bovine mastitis pathogenic Streptococcus, Enterococcus, and Aerococcus species. Phenotypic and biochemical identification methods can be inaccurate and unreliable for species within this group, particularly for Lactococcus spp. As a result, the incidence of Lactococcus spp. on the farm may have been historically underreported and consequently little is known about the clinical importance of this genus as a mastitis pathogen. We used molecular genetic identification methods to accurately differentiate 60 environmental streptococci and streptococci-like bacteria isolated from cows with high somatic cell count and chronic intramammary infection (IMI; >2 somatic cell scores above 4) among 5 geographically distinct farms in New York and Minnesota that exhibited an observed increase in IMI. These isolates were phenotypically identified as Streptococcus uberis and Streptococcus spp. Genetic methods identified 42 isolates (70%) as Lactococcus lactis ssp. lactis, including all 10 isolates originally phenotypically identified as Streptococcus uberis. Antibiotic inhibition testing of all Lc. lactis ssp. lactis showed that 7 isolates were resistant to tetracycline. In the present study, a predominance of Lc. lactis ssp. lactis was identified in association with chronic, clinical bovine IMI among all 5 farms and characterized antimicrobial resistance for treatment therapies. Routine use by mastitis testing labs of molecular identification methods for environmental streptococci and streptococci-like bacteria can further define the role and prevalence of Lc. lactis ssp. lactis in association with bovine IMI and may lead to more targeted therapies. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  10. Genetic transformation of intact Lactococcus lactis subsp. lactis by high-voltage electroporation

    Energy Technology Data Exchange (ETDEWEB)

    McIntyre, D.A.; Harlander, S.K. (Univ. of Minnesota, St. Paul (USA))

    1989-03-01

    The objective of this study was to develop a system for electroporating intact cells of Lactococcus lactis subsp. lactis LM0230 (previously designated Streptococcus lactis LM0230) with a commercially available electroporation unit. Parameters which influenced the efficiency of transformation included growth phase and final concentration of cells, ionic strength of the suspending medium, concentration of plasmid DNA, and the amplitude and duration of the pulse. Washed suspensions of intact cells suspended in deionized distilled water were subjected to one high-voltage electric pulse varying in voltage (300 to 900 V corresponding to field strengths of 5 to 17 kV/cm) and duration (100 {mu}s to 1 s). Transformation efficiencies of 10{sup 3} transformants per {mu}g of DNA were obtained when dense suspensions (final concentration, 5 {times} 10{sup 10} CFU/ml) of stationary-phase cells were subjected to one pulse with a peak voltage of 900 V (field strength, 17 kV/cm) and a pulse duration of 5 ms in the presence of plasmid DNA. Dilution of porated cells in broth medium followed by an expression period of 2 h at 30{degree}C was beneficial in enhancing transformation efficiencies. Plasmids ranging in size from 9.8 to 30.0 kilobase pairs could be transformed by this procedure.

  11. Effect of Glycerol, as Cryoprotectant in the Encapsulation and Freeze Drying of Microspheres Containing Probiotic Cells

    Directory of Open Access Journals (Sweden)

    Oana Lelia Pop

    2015-05-01

    Full Text Available It is reported that probiotics provide several health benefits as they help in maintaining a good balance and composition of intestinal flora, and increase the resistance against invasion of pathogens. Ensuring adequate dosages of probiotics at the time of consumption is a challenge, because several factors during processing and storage affect the viability of probiotic organisms. Major emphasis has been given to protect the microorganisms with the help of encapsulation technique, by addition of different protectants. In this study, probiotic cells (Bifidobacterium lactis 300B were entrapped in alginate/pullulan microspheres. In the encapsulation formula glycerol was used as cryoprotectant in the freeze drying process for long time storage. It was observed that the survival of Bifidobacterium lactis 300B when encapsulated without cryoprotectant was higher than the formula with glycerol in the fresh obtained microspheres. The addition of glycerol was in order to reduce the deep freezing and freeze drying damages. In the chosen formulations, glycerol did not proved protection for the entrapped probiotic cells in the freeze drying process, for which the use of glycerol as cryoprotectant for alginate/pullulan Bifidobacterium lactis 300B entrapment is not recommended.

  12. Spectroscopic Classification of ASASSN-13dn

    Science.gov (United States)

    Martini, P.; Elias, J.; Points, S.; Prieto, J. L.; Shappee, B. J.; Stanek, K. Z.; Kochanek, C. S.; Holoien, T. W.-S.; Jencson, J.; Basu, U.; Beacom, J. F.; Szczygiel, D.; Pojmanski, G.; Brimacombe, J.; Bersier, D.

    2013-12-01

    We obtained optical spectra of ASASSN-13dn (ATel #5665). The candidate was confirmed with the new KOSMOS instrument (Kitt Peak Ohio State Multi-Object Spectrograph), which is presently being commissioned at the KPNO 4-m Mayall telescope. Observations were obtained with both the blue and red VPH grisms (50 min each) for a combined wavelength range of 380nm to 965nm at R ~ 2000. The spectrum of ASASSN-13dn is characteristic of a Type II SN at the redshift of its host galaxy (z=0.023).

  13. The Evolution of gene regulation research in Lactococcus lactis.

    Science.gov (United States)

    Kok, Jan; van Gijtenbeek, Lieke A; de Jong, Anne; van der Meulen, Sjoerd B; Solopova, Ana; Kuipers, Oscar P

    2017-08-01

    Lactococcus lactis is a major microbe. This lactic acid bacterium (LAB) is used worldwide in the production of safe, healthy, tasteful and nutritious milk fermentation products. Its huge industrial importance has led to an explosion of research on the organism, particularly since the early 1970s. The upsurge in the research on L. lactis coincided not accidentally with the advent of recombinant DNA technology in these years. The development of methods to take out and re-introduce DNA in L. lactis, to clone genes and to mutate the chromosome in a targeted way, to control (over)expression of proteins and, ultimately, the availability of the nucleotide sequence of its genome and the use of that information in transcriptomics and proteomics research have enabled to peek deep into the functioning of the organism. Among many other things, this has provided an unprecedented view of the major gene regulatory pathways involved in nitrogen and carbon metabolism and their overlap, and has led to the blossoming of the field of L. lactis systems biology. All of these advances have made L. lactis the paradigm of the LAB. This review will deal with the exciting path along which the research on the genetics of and gene regulation in L. lactis has trodden. © FEMS 2017.

  14. Transforming Lactococcus lactis into a microbial cell factory

    DEFF Research Database (Denmark)

    Petersen, Kia Vest

    the potential of Lactococcus lactis as a platform organism for production of biofuels and-chemicals with a focus on characterization and optimization of the xylose metabolism. The plant isolate L. lactis KF147 was selected as the potential platform organism due to its natural ability to utilize both the pentose....... To simplify further analysis arcA encoding the arginine deiminase was deleted, thus eliminating the arginine catabolism. We found that in L. lactis KF147 xylose is metabolized through two pathways namely the phosphoketolase pathway and the non-oxidative part of the pentose phosphate pathway. The only products......, and ethanol. Three adaptive mutations were identified in AD29. Two is by all accounts involved in regulatory mechanisms either to stress (yhfB) or more globally (ytgF), and the last facilitate improved uptake of xylose (ptnC). Based on the above findings we conclude that L. lactis KF147 possesses many...

  15. Probiotic Lactococcus lactis: A Review

    Directory of Open Access Journals (Sweden)

    Priti Khemariya

    2017-07-01

    Full Text Available Lactococcus lactis plays a critical role in food, dairy and health sectors. In food and dairy industries, it is found in production processes of various fermented products such as sausages, pickled vegetables, beverages such as beer and wine, breads, soymilk kefir, sour milk, butter, cream, fresh cheese and different types of cheeses, like Cheddar, Colby, Cottage cheese, Camembert, cream cheese, Roquefort and Brie. Additionally, there is an increasing interest towards the possible health benefits of the probiotic activity of this organism which generally is species and strain specific and depends upon the survival in gastrointestinal tract with sufficient number. Certain strains have the ability to produce antimicrobial peptide called nisin which exhibits preservative potential. Therefore, application of bacteriocinogenic Lactococcus lactis in food and dairy sectors to preserve foods as a natural way and contributing health promoting attributes due to probiotic activity would definitely fulfil today’s consumer demands. This paper aimed to review the adaptation, antibiotic resistance, therapeutic and preservation potential of bacteriocinogenic and probiotic Lactococcus lactis.

  16. Chorioamnionitis due to Lactococcus lactis cremoris: A case report

    Directory of Open Access Journals (Sweden)

    F. Azouzi

    2015-07-01

    Full Text Available Lactococcus lactis cremoris is rarely involved in human pathology. A thirty two-year old pregnant woman with premature rupture of membrane history presented with chorioamnionitis due to L. lactis cremoris. She underwent an emergency caesarian section and was treated with antibiotics including the association of amoxicillin and clavulanic acid. She was completely recovered. This is the first case to our knowledge of chorioamnionitis due to this organism. Keywords: Chorioamnionitis, Premature rupture of membranes, Lactococcus lactis cremoris

  17. From Genome to Phenotype: An Integrative Approach to Evaluate the Biodiversity of Lactococcus lactis

    Science.gov (United States)

    Laroute, Valérie; Tormo, Hélène; Couderc, Christel; Mercier-Bonin, Muriel; Le Bourgeois, Pascal; Cocaign-Bousquet, Muriel; Daveran-Mingot, Marie-Line

    2017-01-01

    Lactococcus lactis is one of the most extensively used lactic acid bacteria for the manufacture of dairy products. Exploring the biodiversity of L. lactis is extremely promising both to acquire new knowledge and for food and health-driven applications. L. lactis is divided into four subspecies: lactis, cremoris, hordniae and tructae, but only subsp. lactis and subsp. cremoris are of industrial interest. Due to its various biotopes, Lactococcus subsp. lactis is considered the most diverse. The diversity of L. lactis subsp. lactis has been assessed at genetic, genomic and phenotypic levels. Multi-Locus Sequence Type (MLST) analysis of strains from different origins revealed that the subsp. lactis can be classified in two groups: “domesticated” strains with low genetic diversity, and “environmental” strains that are the main contributors of the genetic diversity of the subsp. lactis. As expected, the phenotype investigation of L. lactis strains reported here revealed highly diverse carbohydrate metabolism, especially in plant- and gut-derived carbohydrates, diacetyl production and stress survival. The integration of genotypic and phenotypic studies could improve the relevance of screening culture collections for the selection of strains dedicated to specific functions and applications. PMID:28534821

  18. Efeito e modo de ação das bacteriocinas produzidas por Lactococcus lactis subsp. lactis ITAL 383, ATCC 11454 e CNRZ 150 contra Listeria innocua LIN 11 Effect and mode of action of the bacterioncin produced by Lactococcus. lactis subsp. lactis ITAL 383, ATCC 11454 e CNRZ 150 against Listeria innocua LIN 11

    Directory of Open Access Journals (Sweden)

    Izildinha MORENO

    1999-01-01

    Full Text Available O efeito e o modo de ação das bacteriocinas produzidas por L. lactis subsp. lactis ITAL 383 e CNRZ 150 são similares à nisina de L. lactis subsp. lactis ATCC 11454. Estas bacteriocinas apresentaram um modo de ação bactericida, causando a lise de células de L. innocua LIN 11, associada ao decréscimo da absorbância e da viabilidade celular. O efeito letal foi maior para células em fase exponencial comparativamente à fase estacionária de crescimento. A adsorção dessas bacteriocinas às células de L. innocua LIN 11 foi muito rápida e influenciada pelo pH do meio de suspensão; adsorção máxima foi verificada a pH 6,0 e logo após o contato inicial. Perda completa de adsorção ocorreu em pH 2,0.The effect and mode of action of the bacteriocin produced by L. lactis subsp. lactis ITAL 383 and CNRZ 150 are similar to the nisin produced by L. lactis subsp. lactis ATCC 11454. It was clearly bactericidal, and caused lysis of a strain of L. innocua LIN 11 detected by the decrease of absorbance values and the cell viability. Their lethal effect was considerably higher during the logarithmic growth when compared to the stationary phase. Adsorption developed rapidly and was influenced by the pH value of the suspension medium. Maximum adsorption was observed at pH 6,0 and immediately after initial contact and loss at pH 2,0.

  19. Expression of six peptidases from Lactobacillus helveticus in Lactococcus lactis.

    Science.gov (United States)

    Luoma, S; Peltoniemi, K; Joutsjoki, V; Rantanen, T; Tamminen, M; Heikkinen, I; Palva, A

    2001-03-01

    For development of novel starter strains with improved proteolytic properties, the ability of Lactococcus lactis to produce Lactobacillus helveticus aminopeptidase N (PepN), aminopeptidase C (PepC), X-prolyl dipeptidyl aminopeptidase (PepX), proline iminopeptidase (PepI), prolinase (PepR), and dipeptidase (PepD) was studied by introducing the genes encoding these enzymes into L. lactis MG1363 and its derivatives. According to Northern analyses and enzyme activity measurements, the L. helveticus aminopeptidase genes pepN, pepC, and pepX are expressed under the control of their own promoters in L. lactis. The highest expression level, using a low-copy-number vector, was obtained with the L. helveticus pepN gene, which resulted in a 25-fold increase in PepN activity compared to that of wild-type L. lactis. The L. helveticus pepI gene, residing as a third gene in an operon in its host, was expressed in L. lactis under the control of the L. helveticus pepX promoter. The genetic background of the L. lactis derivatives tested did not affect the expression level of any of the L. helveticus peptidases studied. However, the growth medium used affected both the recombinant peptidase profiles in transformant strains and the resident peptidase activities. The levels of expression of the L. helveticus pepD and pepR clones under the control of their own promoters were below the detection limit in L. lactis. However, substantial amounts of recombinant pepD and PepR activities were obtained in L. lactis when pepD and pepR were expressed under the control of the inducible lactococcal nisA promoter at an optimized nisin concentration.

  20. Autolysis of Lactococcus lactis is influenced by proteolysis

    NARCIS (Netherlands)

    Buist, G; Venema, G; Kok, J.

    1998-01-01

    The autolysin AcmA of Lactococcus lactis was shown to be degraded by the extracellular Lactococcal proteinase PrtP. Autolysis, as evidenced by reduction in optical density of a stationary-phase culture and concomitant release of intracellular proteins, was greatly reduced when L. lactis MG1363 cells

  1. Cloning, Expression, and Functional Characterization of Secondary Amino Acid Transporters of Lactococcus lactis

    NARCIS (Netherlands)

    Trip, Hein; Mulder, Niels L.; Lolkema, Juke S.

    Fourteen genes encoding putative secondary amino acid transporters were identified in the genomes of Lactococcus lactis subsp. cremoris strains MG1363 and SK11 and L. lactis subsp. lactis strains IL1403 and KF147, 12 of which were common to all four strains. Amino acid uptake in L. lactis cells

  2. Antimicrobial susceptibilities and random amplified polymorphic DNA-PCR fingerprint characterization of Lactococcus lactis ssp. lactis and Lactococcus garvieae isolated from bovine intramammary infections.

    Science.gov (United States)

    Plumed-Ferrer, C; Barberio, A; Franklin-Guild, R; Werner, B; McDonough, P; Bennett, J; Gioia, G; Rota, N; Welcome, F; Nydam, D V; Moroni, P

    2015-09-01

    In total, 181 streptococci-like bacteria isolated from intramammary infections (IMI) were submitted by a veterinary clinic to Quality Milk Production Services (QMPS, Cornell University, Ithaca, NY). The isolates were characterized by sequence analysis, and 46 Lactococcus lactis ssp. lactis and 47 Lactococcus garvieae were tested for susceptibility to 17 antibiotics. No resistant strains were found for β-lactam antibiotics widely used in clinical practice (penicillin, ampicillin, and amoxicillin), and all minimum inhibitory concentrations (MIC) were far from the resistance breakpoints. Eight strains had MIC intermediate to cefazolin. The random amplification of polymorphic DNA (RAPD)-PCR fingerprint patterns showed a slightly higher heterogeneity for Lc. lactis ssp. lactis isolates than for Lc. garvieae isolates. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  3. Expression of prophage-encoded endolysins contributes to autolysis of Lactococcus lactis.

    Science.gov (United States)

    Visweswaran, Ganesh Ram R; Kurek, Dorota; Szeliga, Monika; Pastrana, Francisco Romero; Kuipers, Oscar P; Kok, Jan; Buist, Girbe

    2017-02-01

    Analysis of autolysis of derivatives of Lactococcus lactis subsp. cremoris MG1363 and subsp. lactis IL1403, both lacking the major autolysin AcmA, showed that L. lactis IL1403 still lysed during growth while L. lactis MG1363 did not. Zymographic analysis revealed that a peptidoglycan hydrolase activity of around 30 kDa is present in cell extracts of L. lactis IL1403 that could not be detected in strain MG1363. A comparison of all genes encoding putative peptidoglycan hydrolases of IL1403 and MG1363 led to the assumption that one or more of the 99 % homologous 27.9-kDa endolysins encoded by the prophages bIL285, bIL286 and bIL309 could account for the autolysis phenotype of IL1403. Induced expression of the endolysins from bIL285, bIL286 or bIL309 in L. lactis MG1363 resulted in detectable lysis or lytic activity. Prophage deletion and insertion derivatives of L. lactis IL1403 had a reduced cell lysis phenotype. RT-qPCR and zymogram analysis showed that each of these strains still expressed one or more of the three phage lysins. A homologous gene and an endolysin activity were also identified in the natural starter culture L. lactis subsp. cremoris strains E8, Wg2 and HP, and the lytic activity could be detected under growth conditions that were identical as those used for IL1403. The results presented here show that these endolysins of L. lactis are expressed during normal growth and contribute to autolysis without production of (lytic) phages. Screening for natural strains expressing homologous endolysins could help in the selection of strains with enhanced autolysis and, thus, cheese ripening properties.

  4. Antimicrobial activity of Lactobacillus and Bifidobacterium strains against pathogenic microorganisms “in vitro”Atividade antimicrobiana de Lactobacillus e Bifodobacterium frente a microrganismos patogênicos “in vitro”

    Directory of Open Access Journals (Sweden)

    Giselle Nobre Costa

    2012-10-01

    Full Text Available Lactobacilli and bifidobacteria have a long history of safe use in foods. These bacteria have biotechnological characteristics of interest such as the inhibition of pathogens. In this work, two lactobacilli strain and a bifidobacterium strain isolated from human gut were evaluated concerning to their ability to inhibit pathogenic microorganisms in foods by diffusion agar tests. Moreover, we assessed the metabolites produced in culture broth under static and shaking growth to simulate anaerobiosis and aerobiosis conditions, respectively. L. acidophilus LA5, L. plantarum DCTA 8420 and B. lactis DCTA 8724 showed ability to inhibit S. aureus FRI 196, strains producer toxins A and D, as well as B. cereus ATCC 25923, E. coli ATCC 25922 and S. Enteritidis, whose inhibition halos reached, on average, 24 mm in diameter. In the agar diffusion method with concentrated culture medium, it was possible to observe the effect of oxygen on the production of toxic substances. This result showed that cultivation of Lactobacillus under aerobic conditions seems to exert greater inhibitory effect, whereas for Bifidobacterium strain the effect was the opposite.Lactobacilos e bifidobactérias apresentam um longo histórico de uso seguro em alimentos, além de apresentarem características de interesse biotecnológico como a inibição de patógenos. Neste trabalho duas linhagens de lactobacilos e uma de bifidobactéria, isoladas do intestino humano, foram avaliadas em testes de difusão em ágar, quanto à capacidade de inibição de microrganismos patogênicos de ocorrência comuns em toxinfecções alimentares. Adicionalmente, foram avaliados os metabólitos produzidos em caldo de cultivo estático e em agitação para simular condições de anaerobiose a aerobiose, respectivamente. As três bactérias, L. acidophilus LA5, L. plantarum DCTA 8420 e B. lactis DCTA 8724 apresentaram capacidade de inibição para S. aureus FRI 196 linhagem produtora de toxinas A e D

  5. Combined Transcriptome and Proteome Analysis of Bifidobacterium animalis subsp. lactis BB-12 Grown on Xylo-Oligosaccharides and a Model of Their Utilization

    DEFF Research Database (Denmark)

    Gilad, Ofir; Jacobsen, Susanne; Stuer-Lauridsen, B.

    2010-01-01

    -documented and widely used probiotic strain B. animalis subsp. lactis BB-12, a combined proteomic and transcriptomic approach was applied, involving DNA microarrays, real-time quantitative PCR (qPCR), and two-dimensional difference gel electrophoresis (2D-DIGE) analyses of samples obtained from cultures grown on either...... of these (beta-D-xylosidase, sugar-binding protein, and xylose isomerase) showed higher abundance on XOS. Based on the obtained results, a model for the catabolism of XOS in BB-12 is suggested, according to which the strain utilizes an ABC (ATP-binding cassette) transport system (probably for oligosaccharides...

  6. Quantitative PCR for the specific quantification of Lactococcus lactis and Lactobacillus paracasei and its interest for Lactococcus lactis in cheese samples.

    Science.gov (United States)

    Achilleos, Christine; Berthier, Françoise

    2013-12-01

    The first objective of this work was to develop real-time quantitative PCR (qPCR) assays to quantify two species of mesophilic lactic acid bacteria technologically active in food fermentation, including cheese making: Lactococcus lactis and Lactobacillus paracasei. The second objective was to compare qPCR and plate counts of these two species in cheese samples. Newly designed primers efficiently amplified a region of the tuf gene from the target species. Sixty-three DNA samples from twenty different bacterial species, phylogenetically related or commonly found in raw milk and dairy products, were selected as positive and negative controls. Target DNA was successfully amplified showing a single peak on the amplicon melting curve; non-target DNA was not amplified. Quantification was linear over 5 log units (R(2) > 0.990), down to 22 gene copies/μL per well for Lc. lactis and 73 gene copies/μL per well for Lb. paracasei. qPCR efficiency ranged from 82.9% to 93.7% for Lc. lactis and from 81.1% to 99.5% for Lb. paracasei. At two stages of growth, Lc. lactis was quantified in 12 soft cheeses and Lb. paracasei in 24 hard cooked cheeses. qPCR proved to be useful for quantifying Lc. lactis, but not Lb. paracasei. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Cell growth and resistance of Lactococcus lactis subsp. lactis TOMSC161 following freezing, drying and freeze-dried storage are differentially affected by fermentation conditions.

    Science.gov (United States)

    Velly, H; Fonseca, F; Passot, S; Delacroix-Buchet, A; Bouix, M

    2014-09-01

    To investigate the effects of fermentation parameters on the cell growth and on the resistance to each step of the freeze-drying process of Lactococcus lactis subsp. lactis TOMSC161, a natural cheese isolate, using a response surface methodology. Cells were cultivated at different temperatures (22, 30 and 38°C) and pH (5·6, 6·2 and 6·8) and were harvested at different growth phases (0, 3 and 6 h of stationary phase). Cultivability and acidification activity losses of Lc. lactis were quantified after freezing, drying, 1 and 3 months of storage at 4 and 25°C. Lactococcus lactis was not damaged by freezing but was sensitive to drying and to ambient temperature storage. Moreover, the fermentation temperature and the harvesting time influenced the drying resistance of Lc. lactis. Lactococcus lactis cells grown in a whey-based medium at 32°C, pH 6·2 and harvested at late stationary phase exhibited both an optimal growth and the highest resistance to freeze-drying and storage. A better insight on the individual and interaction effects of fermentation parameters made it possible the freeze-drying and storage preservation of a sensitive strain of technological interest. Evidence on the particularly damaging effect of the drying step and the high-temperature storage is presented. © 2014 The Society for Applied Microbiology.

  8. Nucleotide Sequence and Analysis of an orotate transporter-containing plasmid isolated from the Lactococcus lactis ssp. lactis biovar diacetylactis strain DB0410

    DEFF Research Database (Denmark)

    Defoor, Els Marie Celine; Martinussen, Jan

    A new lactococcal plasmid, pDBORO, was isolated from the Lactococcus lactis ssp. lactis biovar diacetylactis strain DB0410 responsible for the sensitivity of DB0410 towards the pyrimidine-analog 5´-fluoroorotate. The plasmid pDBORO amounts to 16404 bp and its complete nucleotide sequence has been...

  9. Bifidobacterium bombi sp. nov., a new bifidobacterium from the bumblebee digestive tract

    Czech Academy of Sciences Publication Activity Database

    Killer, Jiří; Kopečný, Jan; Mrázek, Jakub; Rada, V.; Benada, Oldřich; Koppová, Ingrid; Havlík, J.; Straka, J.

    2009-01-01

    Roč. 59, č. 8 (2009), s. 2020-2024 ISSN 1466-5026 R&D Projects: GA AV ČR 1QS500200572 Institutional research plan: CEZ:AV0Z50450515; CEZ:AV0Z50200510 Keywords : bifidobacterium bombi * anaerobic bacteria Subject RIV: EE - Microbiology, Virology Impact factor: 2.113, year: 2009

  10. Comparative study of Bifidobacterium animalis, Escherichia coli, Lactobacillus casei and Saccharomyces boulardii probiotic properties.

    Science.gov (United States)

    Martins, Flaviano S; Silva, Aparecida A; Vieira, Angélica T; Barbosa, Flávio H F; Arantes, Rosa M E; Teixeira, Mauro M; Nicoli, Jacques Robert

    2009-08-01

    The present work investigates some probiotic properties of four different microorganisms (Bifidobacterium animalis var. lactis BB-12, Escherichia coli EMO, Lactobacillus casei and Saccharomyces boulardii). In vitro and in vivo tests were carried out to compare cell wall hydrophobicity, production of antagonistic substances, survival capacity in the gastrointestinal tract of germ-free mice without pathological consequence, and immune modulation by stimulation of Küpffer cells, intestinal sIgA and IL-10 levels. In vitro antagonism against pathogenic bacteria and yeast was only observed for the probiotic bacteria B. animalis and L. casei. The hydrophobic property of the cell wall was higher for B. animalis and E. coli EMO, and this property could be responsible for a better ability to colonize the gastrointestinal tract of germ-free mice. Higher levels of sIgA were observed mainly for S. boulardii, followed by E. coli EMO and B. animalis, and only S. boulardii induced a significant higher level of IL-10. In conclusion, for a probiotic use, S. boulardii presented better characteristics in terms of immunomodulation, and B. animalis and L. casei for antagonistic substance production. The knowledge of the different probiotic properties could be used to choice the better microorganism depending on the therapeutic or prophylactic application.

  11. Differential expression of proteins and genes in the lag phase of Lactococcus lactis subsp lactis grown in synthetic medium and reconstituted skim milk

    DEFF Research Database (Denmark)

    Larsen, N.; Boye, Mette; Jakobsen, Marianne

    2006-01-01

    We investigated protein and gene expression in the lag phase of Lactococcus lactis subsp. lactis CNRZ 157 and compared it to the exponential and stationary phases. By means of two-dimensional polyacrylamide gel electrophoresis, 28 highly expressed lag-phase proteins, implicated in nucleotide meta...

  12. Engineering of the Lactococcus lactis serine proteinase by construction of hybrid enzymes

    NARCIS (Netherlands)

    Boerrigter, Ingrid J.; Buist, Girbe; Haandrikman, Alfred J.; Nijhuis, Monique; Reuver, Marjon B. de; Siezen, Roland J.; Venema, Gerhardus; Vos, Willem M. de; Kok, Jan

    Plasmids containing wild-type and hybrid proteinase genes were constructed from DNA fragments of the prtP genes of Lactococcus lactis strains Wg2 and SK11. These plasmids were introduced into the plasmid-free strain L. lactis MG1363. The serine proteinases produced by these L. lactis strains were

  13. Alternative lactose catabolic pathway in Lactococcus lactis IL1403

    NARCIS (Netherlands)

    Aleksandrzak-Piekarczyk, T; Kok, J; Renault, P; Bardowski, J

    2005-01-01

    In this study, we present a glimpse of the diversity of Lactococcus lactis subsp. lactis IL1403 beta-galactosidase phenotype-negative mutants isolated by negative selection on solid media containing cellobiose or lactose and X-Gal (5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside), and we

  14. Use of a genetically enhanced, pediocin-producing starter culture, Lactococcus lactis subsp. lactis MM217, to control Listeria monocytogenes in cheddar cheese

    NARCIS (Netherlands)

    Buyong, N; Kok, J; Luchansky, JB

    1998-01-01

    Cheddar cheese was prepared with Lactococcus lactis subsp, lactis MM217, a starter culture which contains pMC117 coding for pediocin PA-1, About 75 liters of pasteurized milk (containing ca, 3.6% fat) was inoculated with strain MM217 (ca, 10(6) CFU per ml) and a mixture of three Listeria

  15. Lactococcus lactis Metabolism and Gene Expression during Growth on Plant Tissues

    Science.gov (United States)

    Golomb, Benjamin L.

    2014-01-01

    Lactic acid bacteria have been isolated from living, harvested, and fermented plant materials; however, the adaptations these bacteria possess for growth on plant tissues are largely unknown. In this study, we investigated plant habitat-specific traits of Lactococcus lactis during growth in an Arabidopsis thaliana leaf tissue lysate (ATL). L. lactis KF147, a strain originally isolated from plants, exhibited a higher growth rate and reached 7.9-fold-greater cell densities during growth in ATL than the dairy-associated strain L. lactis IL1403. Transcriptome profiling (RNA-seq) of KF147 identified 853 induced and 264 repressed genes during growth in ATL compared to that in GM17 laboratory culture medium. Genes induced in ATL included those involved in the arginine deiminase pathway and a total of 140 carbohydrate transport and metabolism genes, many of which are involved in xylose, arabinose, cellobiose, and hemicellulose metabolism. The induction of those genes corresponded with L. lactis KF147 nutrient consumption and production of metabolic end products in ATL as measured by gas chromatography-time of flight mass spectrometry (GC-TOF/MS) untargeted metabolomic profiling. To assess the importance of specific plant-inducible genes for L. lactis growth in ATL, xylose metabolism was targeted for gene knockout mutagenesis. Wild-type L. lactis strain KF147 but not an xylA deletion mutant was able to grow using xylose as the sole carbon source. However, both strains grew to similarly high levels in ATL, indicating redundancy in L. lactis carbohydrate metabolism on plant tissues. These findings show that certain strains of L. lactis are well adapted for growth on plants and possess specific traits relevant for plant-based food, fuel, and feed fermentations. PMID:25384484

  16. Lactose-mediated carbon catabolite repression of putrescine production in dairy Lactococcus lactis is strain dependent.

    Science.gov (United States)

    del Rio, Beatriz; Ladero, Victor; Redruello, Begoña; Linares, Daniel M; Fernández, Maria; Martín, Maria Cruz; Alvarez, Miguel A

    2015-06-01

    Lactococcus lactis is the lactic acid bacterial (LAB) species most widely used as a primary starter in the dairy industry. However, several strains of L. lactis produce the biogenic amine putrescine via the agmatine deiminase (AGDI) pathway. We previously reported the putrescine biosynthesis pathway in L. lactis subsp. cremoris GE2-14 to be regulated by carbon catabolic repression (CCR) via glucose but not lactose (Linares et al., 2013). The present study shows that both these sugars repress putrescine biosynthesis in L. lactis subsp. lactis T3/33, a strain isolated from a Spanish artisanal cheese. Furthermore, we demonstrated that both glucose and lactose repressed the transcriptional activity of the aguBDAC catabolic genes of the AGDI route. Finally, a screening performed in putrescine-producing dairy L. lactis strains determined that putrescine biosynthesis was repressed by lactose in all the L. lactis subsp. lactis strains tested, but in only one L. lactis subsp. cremoris strain. Given the obvious importance of the lactose-repression in cheese putrescine accumulation, it is advisable to consider the diversity of L. lactis in this sense and characterize consequently the starter cultures to select the safest strains. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Production and crystallization of α-phosphoglucomutase from Lactococcus lactis

    International Nuclear Information System (INIS)

    Nogly, Przemyslaw; Castro, Rute; Rosa, Matteo de; Neves, Ana Rute; Santos, Helena; Archer, Margarida

    2012-01-01

    α-Phosphoglucomutase from L. lactis, a homologue of human phosphomannomutase 1, was produced and crystallized. X-ray diffraction data were collected to 1.5 Å resolution. α-Phosphoglucomutase (α-PGM) is an enzyme that is essential for the growth of Lactococcus lactis. The enzyme links bacterial anabolism with sugar utilization through glycolysis by catalyzing the reversible interconversion of glucose 6-phosphate and α-glucose 1-phosphate. The gene encoding α-PGM was cloned and overexpressed in L. lactis. The purified protein was functionally active and was crystallized with ammonium sulfate as a precipitant using vapour-diffusion and seeding techniques. Optimized crystals diffracted to 1.5 Å resolution at a synchrotron source

  18. Expression of biologically active murine interleukin-18 in Lactococcus lactis.

    Science.gov (United States)

    Feizollahzadeh, Sadegh; Khanahmad, Hossein; Rahimmanesh, Ilnaz; Ganjalikhani-Hakemi, Mazdak; Andalib, Alireza; Sanei, Mohammad Hossein; Rezaei, Abbas

    2016-11-01

    The food-grade bacterium Lactococcus lactis is increasingly used for heterologous protein expression in therapeutic and industrial applications. The ability of L. lactis to secrete biologically active cytokines may be used for the generation of therapeutic cytokines. Interleukin (IL)-18 enhances the immune response, especially on mucosal surfaces, emphasizing its therapeutic potential. However, it is produced as an inactive precursor and has to be enzymatically cleaved for maturation. We genetically manipulated L. lactis to secrete murine IL-18. The mature murine IL-18 gene was inserted downstream of a nisin promoter in pNZ8149 plasmid and the construct was used to transform L. lactis NZ3900. The transformants were selected on Elliker agar and confirmed by restriction enzyme digestion and sequencing. The expression and secretion of IL-18 protein was verified by SDS-PAGE, western blotting and ELISA. The biological activity of recombinant IL-18 was determined by its ability to induce interferon (IFN)-γ production in L. lactis co-cultured with murine splenic T cells. The amounts of IL-18 in bacterial lysates and supernatants were 3-4 μg mL -1 and 0.6-0.7 ng mL -1 , respectively. The successfully generated L. lactis strain that expressed biologically active murine IL-18 can be used to evaluate the possible therapeutic effects of IL-18 on mucosal surfaces. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. Comparative and functional genomics of the Lactococcus lactis taxon; insights into evolution and niche adaptation.

    Science.gov (United States)

    Kelleher, Philip; Bottacini, Francesca; Mahony, Jennifer; Kilcawley, Kieran N; van Sinderen, Douwe

    2017-03-29

    Lactococcus lactis is among the most widely studied lactic acid bacterial species due to its long history of safe use and economic importance to the dairy industry, where it is exploited as a starter culture in cheese production. In the current study, we report on the complete sequencing of 16 L. lactis subsp. lactis and L. lactis subsp. cremoris genomes. The chromosomal features of these 16 L. lactis strains in conjunction with 14 completely sequenced, publicly available lactococcal chromosomes were assessed with particular emphasis on discerning the L. lactis subspecies division, evolution and niche adaptation. The deduced pan-genome of L. lactis was found to be closed, indicating that the representative data sets employed for this analysis are sufficient to fully describe the genetic diversity of the taxon. Niche adaptation appears to play a significant role in governing the genetic content of each L. lactis subspecies, while (differential) genome decay and redundancy in the dairy niche is also highlighted.

  20. Statistical optimization of cell disruption techniques for releasing intracellular X-prolyl dipeptidyl aminopeptidase from Lactococcus lactis spp. lactis.

    Science.gov (United States)

    Üstün-Aytekin, Özlem; Arısoy, Sevda; Aytekin, Ali Özhan; Yıldız, Ece

    2016-03-01

    X-prolyl dipeptidyl aminopeptidase (PepX) is an intracellular enzyme from the Gram-positive bacterium Lactococcus lactis spp. lactis NRRL B-1821, and it has commercial importance. The objective of this study was to compare the effects of several cell disruption methods on the activity of PepX. Statistical optimization methods were performed for two cavitation methods, hydrodynamic (high-pressure homogenization) and acoustic (sonication), to determine the more appropriate disruption method. Two level factorial design (2FI), with the parameters of number of cycles and pressure, and Box-Behnken design (BBD), with the parameters of cycle, sonication time, and power, were used for the optimization of the high-pressure homogenization and sonication methods, respectively. In addition, disruption methods, consisting of lysozyme, bead milling, heat treatment, freeze-thawing, liquid nitrogen, ethylenediaminetetraacetic acid (EDTA), Triton-X, sodium dodecyl sulfate (SDS), chloroform, and antibiotics, were performed and compared with the high-pressure homogenization and sonication methods. The optimized values of high-pressure homogenization were one cycle at 130 MPa providing activity of 114.47 mU ml(-1), while sonication afforded an activity of 145.09 mU ml(-1) at 28 min with 91% power and three cycles. In conclusion, sonication was the more effective disruption method, and its optimal operation parameters were manifested for the release of intracellular enzyme from a L. lactis spp. lactis strain, which is a Gram-positive bacterium. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Dual recombinant Lactococcus lactis for enhanced delivery of DNA vaccine reporter plasmid pPERDBY.

    Science.gov (United States)

    Yagnik, Bhrugu; Sharma, Drashya; Padh, Harish; Desai, Priti

    2017-04-01

    Food grade Lactococcus lactis has been widely used as an antigen and DNA delivery vehicle. We have previously reported the use of non-invasive L. lactis to deliver the newly constructed immunostimulatory DNA vaccine reporter plasmid, pPERDBY. In the present report, construction of dual recombinant L. lactis expressing internalin A of Listeria monocytogenes and harboring pPERDBY (LL InlA + pPERDBY) to enhance the efficiency of delivery of DNA by L. lactis is outlined. After confirmation and validation of LL InlA + pPERDBY, its DNA delivery potential was compared with previously developed non-invasive r- L. lactis::pPERDBY. The use of invasive L. lactis resulted in around threefold increases in the number of enhanced green fluorescent protein-expressing Caco-2 cells. These findings reinforce the prospective application of invasive strain of L. lactis for delivery of DNA/RNA and antigens. © 2017 The Societies and John Wiley & Sons Australia, Ltd.

  2. DN detection during SLSF tests

    International Nuclear Information System (INIS)

    Braid, T.H.; Harper, H.A.; Wilson, R.E.; Baldwin, R.D.; Gilbert, D.M.; Baxter, D.E.; Gillins, R.L.; Jeffries, G.L.

    1982-01-01

    During two tests in the Sodium Loop Safety Facility (W2 and P4), two systems were operated to detect delayed neutrons from exposed fuel. One monitored directly the sodium in the in-pile loop with a transit delay from the flux region of approx.2 seconds; the other conducted a sample stream of sodium to external detectors with a transit delay which could be varied from approx.10 to approx. 40 seconds. Detectors of a wide range of sensitivity were operated in pulse and current mode; DN signals varying from 2 recoil to many grams of molten fuel could be recorded reliably without saturation. During the W2 and P4 tests a continuous DN record was made. Massive fuel failure signals were observed during reactor transients in both tests, including events interpreted as fuel melting and exposure of large areas. The steady signal from the blockage in P4 was studied as a function of reactor power and sodium temperature

  3. A review on Lactococcus lactis: from food to factory.

    Science.gov (United States)

    Song, Adelene Ai-Lian; In, Lionel L A; Lim, Swee Hua Erin; Rahim, Raha Abdul

    2017-04-04

    Lactococcus lactis has progressed a long way since its discovery and initial use in dairy product fermentation, to its present biotechnological applications in genetic engineering for the production of various recombinant proteins and metabolites that transcends the heterologous species barrier. Key desirable features of this gram-positive lactic acid non-colonizing gut bacteria include its generally recognized as safe (GRAS) status, probiotic properties, the absence of inclusion bodies and endotoxins, surface display and extracellular secretion technology, and a diverse selection of cloning and inducible expression vectors. This have made L. lactis a desirable and promising host on par with other well established model bacterial or yeast systems such as Escherichia coli, Salmonella cerevisiae and Bacillus subtilis. In this article, we review recent technological advancements, challenges, future prospects and current diversified examples on the use of L. lactis as a microbial cell factory. Additionally, we will also highlight latest medical-based applications involving whole-cell L. lactis as a live delivery vector for the administration of therapeutics against both communicable and non-communicable diseases.

  4. Enhanced heterologous protein productivity by genome reduction in Lactococcus lactis NZ9000.

    Science.gov (United States)

    Zhu, Duolong; Fu, Yuxin; Liu, Fulu; Xu, Haijin; Saris, Per Erik Joakim; Qiao, Mingqiang

    2017-01-03

    The implementation of novel chassis organisms to be used as microbial cell factories in industrial applications is an intensive research field. Lactococcus lactis, which is one of the most extensively studied model organisms, exhibits superior ability to be used as engineered host for fermentation of desirable products. However, few studies have reported about genome reduction of L. lactis as a clean background for functional genomic studies and a model chassis for desirable product fermentation. Four large nonessential DNA regions accounting for 2.83% in L. lactis NZ9000 (L. lactis 9 k) genome (2,530,294 bp) were deleted using the Cre-loxP deletion system as the first steps toward a minimized genome in this study. The mutants were compared with the parental strain in several physiological traits and evaluated as microbial cell factories for heterologous protein production (intracellular and secretory expression) with the red fluorescent protein (RFP) and the bacteriocin leucocin C (LecC) as reporters. The four mutants grew faster, yielded enhanced biomass, achieved increased adenosine triphosphate content, and diminished maintenance demands compared with the wild strain in the two media tested. In particular, L. lactis 9 k-4 with the largest deletion was identified as the optimum candidate host for recombinant protein production. With nisin induction, not only the transcriptional efficiency but also the production levels of the expressed reporters were approximately three- to fourfold improved compared with the wild strain. The expression of lecC gene controlled with strong constitutive promoters P5 and P8 in L. lactis 9 k-4 was also improved significantly. The genome-streamlined L. lactis 9 k-4 outcompeted the parental strain in several physiological traits assessed. Moreover, L. lactis 9 k-4 exhibited good properties as platform organism for protein production. In future works, the genome of L. lactis will be maximally reduced by using our specific design

  5. Effects of Lactococcus lactis on composition of intestinal microbiota: Role of nisin

    DEFF Research Database (Denmark)

    Bernbom, Nete; Licht, Tine Rask; Brogren, Carl-Henrik

    2006-01-01

    This study examined the ability of (i) pure nisin, (ii) nisin-producing Lactococcus lactis strain CHCC5826, and (iii) the non-nisin-producing L. lactis strain CHCH2862 to affect the composition of the intestinal microbiota of human flora-associated rats. The presence of both the nisin-producing a......This study examined the ability of (i) pure nisin, (ii) nisin-producing Lactococcus lactis strain CHCC5826, and (iii) the non-nisin-producing L. lactis strain CHCH2862 to affect the composition of the intestinal microbiota of human flora-associated rats. The presence of both the nisin...... in the rat fecal microbiota were observed after dosage with nisin. Pearson cluster analysis of denaturing gradient gel electrophoresis profiles of the 16S rRNA genes present in the fecal microbial population revealed that the microbiota of animals dosed with either of the two L. lactis strains were different...

  6. Data of evolutionary structure change: 2QU0A-2DN1B [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available >A 2QU0A WGKVGGNAGAYGence> HHHH...2QU0A-2DN1B 2QU0 2DN1 A B VLSAADKSNVKAAWGKVGGNAGAYGAEALERMFLSFPTT...index>0 2DN1 B 2DN1B ...ence>WGKVN--VDEVGence> GGG --HHHHH VAL CA 367 GLY CA 400 2QU0

  7. Quantitative Real-Time PCR Assays To Identify and Quantify Fecal Bifidobacterium Species in Infants Receiving a Prebiotic Infant Formula

    OpenAIRE

    Haarman, Monique; Knol, Jan

    2005-01-01

    A healthy intestinal microbiota is considered to be important for priming of the infants' mucosal and systemic immunity. Breast-fed infants typically have an intestinal microbiota dominated by different Bifidobacterium species. It has been described that allergic infants have different levels of specific Bifidobacterium species than healthy infants. For the accurate quantification of Bifidobacterium adolescentis, Bifidobacterium angulatum, Bifidobacterium bifidum, Bifidobacterium breve, Bifid...

  8. Fate of Lactococcus lactis starter cultures during late ripening in cheese models.

    Science.gov (United States)

    Ruggirello, Marianna; Cocolin, Luca; Dolci, Paola

    2016-10-01

    The presence of Lactococcus lactis, commonly employed as starter culture, was, recently, highlighted and investigated during late cheese ripening. Thus, the main goal of the present study was to assess the persistence and viability of this microorganism throughout manufacturing and ripening of model cheeses. Eight commercial starters, constituted of L. lactis subsp. lactis and L. lactis subsp. cremoris, were inoculated in pasteurized milk in order to manufacture miniature cheeses, ripened for six months. Samples were analysed at different steps (milk after inoculum, curd after cutting, curd after pressing and draining, cheese immediately after salting and cheese at 7, 15, 30, 60, 90, 120, 150 and 180 days of ripening) and submitted to both culture-dependent (traditional plating on M17) and -independent analysis (reverse transcription-quantitative PCR). On the basis of direct RNA analysis, L. lactis populations were detected in all miniature cheeses up to the sixth month of ripening, confirming the presence of viable cells during the whole ripening process, including late stages. Noteworthy, L. lactis was detected by RT-qPCR in cheese samples also when traditional plating failed to indicate its presence. This discrepancy could be explain with the fact that lactococci, during ripening process, enter in a stressed physiological state (viable not culturable, VNC), which might cause their inability to grow on synthetic medium despite their viability in cheese matrix. Preliminary results obtained by "resuscitation" assays corroborated this hypothesis and 2.5% glucose enrichment was effective to recover L. lactis cells in VNC state. The capability of L. lactis to persist in late ripening, and the presence of VNC cells which are known to shift their catabolism to peptides and amino acids consumption, suggests a possible technological role of this microorganism in cheese ripening with a possible impact on flavour formation. Copyright © 2016 Elsevier Ltd. All rights

  9. Characterization of Probiotic Fermented Milk Prepared by Different Inoculation Size of Mesophilic and Thermophilic Lactic Acid Bacteria

    Directory of Open Access Journals (Sweden)

    Sara Nasiri Boosjin

    2016-10-01

    Full Text Available Background and Objectives: Importance of development of novel probiotic fermented milk and challenge made for its acceptability is well known. In this research, the impact of different inoculation sizes of yogurt and DL-type starter culture (mesophilic and thermophilic LAB on titratable acidity, viscosity, sensorial and microbial properties of fermented milk was investigated; and finally, probiotic Langfil was produced.Materials and Methods: Fermented milk produced by 1, 2 and 3% v v-1 inocula consisting thermophilic: mesophilic starter cultures 10:90 (Lactococcus lactis subsp. lactis, Lactococcus lactis subsp. cremoris, Lactococcus lactis subsp. lactis, Lactococcus lactis subsp. lactis biovar. diacetylactis and Leuconostoc mesenteroides subsp. cremoris. Streptococcus thermophilus and Lactobacillus delbrueckii subsp. Bulgaricus were analyzed for determination of titratable acidity, viscosity, viability of mesophilic starter cultures and sensory properties on days 5, 10, and 15 of storage at 4°C. Then, the most suitable treatments were selected for the producing probiotic Langfil, containing probiotic starter culture (2% v v-1 inoculums with equal ratio of Lactobacillus acidophilus and Bifidobacterium bifidum. Lactococcus lactis and L. cremoris were counted on M17 agar, while Leuconostoc and Lactobacillus were counted aerobically on tomato juice agar and MRS bile agar, respectively. Bifidobacterium was cultured anaerobically on MRS bile agar. Sensory evaluation was carried out by ten trained panelists, based on a nine-point hedonic scale during the cold storage.Results and Conclusion: According to results, the best organoleptic properties were achieved in the product prepared with 2% the mesophilic and thermophilic starter cultures and 2% probiotic. This product had a high viscosity. An Iranian probiotic Langfil with desired properties was produced using the best treatment prepared.Conflict of interests: The authors declare no conflict of

  10. Secretory expression of a heterologous nattokinase in Lactococcus lactis.

    Science.gov (United States)

    Liang, Xiaobo; Zhang, Lixin; Zhong, Jin; Huan, Liandong

    2007-05-01

    Nattokinase has been reported as an oral health product for the prevention of atherosclerosis. We developed a novel strategy to express a nattokinase from Bacillus subtilis in a live delivery vehicle, Lactococcus lactis. Promoter P( nisZ) and signal peptide SP(Usp) were used for inducible and secretory expression of nattokinase in L. lactis. Western blotting analysis demonstrated that nattokinase was successfully expressed, and about 94% of the enzyme was secreted to the culture. The recombinant nattokinase showed potent fibrinolytic activity, equivalent to 41.7 urokinase units per milliliter culture. Expression and delivery of such a fibrinolytic enzyme in the food-grade vehicle L. lactis would facilitate the widespread application of nattokinase in the control and prevention of thrombosis diseases.

  11. Lactococcus lactis As a Versatile Vehicle for Tolerogenic Immunotherapy

    Science.gov (United States)

    Cook, Dana P.; Gysemans, Conny; Mathieu, Chantal

    2018-01-01

    Genetically modified Lactococcus lactis bacteria have been engineered as a tool to deliver bioactive proteins to mucosal tissues as a means to exert both local and systemic effects. They have an excellent safety profile, the result of years of human consumption in the food industry, as well as a lack of toxicity and immunogenicity. Also, containment strategies have been developed to promote further application as clinical protein-based therapeutics. Here, we review technological advancements made to enhanced the potential of L. lactis as live biofactories and discuss some examples of tolerogenic immunotherapies mediated by mucosal drug delivery via L. lactis. Additionally, we highlight their use to induce mucosal tolerance by targeted autoantigen delivery to the intestine as an approach to reverse autoimmune type 1 diabetes. PMID:29387056

  12. Surface proteins of bacteria of the genus Bifidobacterium 

    Directory of Open Access Journals (Sweden)

    Ewa Dylus

    2013-05-01

    Full Text Available Beneficial effects due to the presence of probiotic bacteria of the genus Bifidobacterium in the human intestinal tract are still an interesting object of study. So far activities have been confirmed of bifidobacteria in stimulation of the host immune system, stimulation of tumor cell apoptosis, improvement of bowel motility, alleviation of symptoms of lactose intolerance, cholesterol lowering capacity, prevention and treatment of diarrhea and irritable bowel syndrome, alleviation of allergy or atopic dermatitis, maintenance of homeostasis of the intestine, and stimulation of the development of normal intestinal microflora in infants. A multitude of therapeutic properties encourages researchers to investigate the possibility of using the potential of Bifidobacterium in the prevention and treatment of other conditions such as rheumatoid arthritis and depression. Although it is known that the beneficial effects are due to intestinal mucosal colonization by these bacteria, the cell components responsible for the colonization are still not determined. In addition to the beneficial effects of probiotic administration, there were also negative effects including sepsis. Therefore research has been directed to identify specific components of Bifidobacterium responsible for probiotic effects. Currently researchers are focused on identifying, isolating and evaluating the properties of surface proteins that are probably involved in the adhesion of bacterial cells to the intestinal epithelium, improving colonization. This paper is an overview of current knowledge on Bifidobacterium surface proteins. The ways of transport and anchoring proteins in Gram-positive bacterial cells, the assembly of cell wall, and a description of the genus Bifidobacterium are presented.

  13. Degradative capacities and bioaugmentation potential of an anaerobic benzene-degrading bacterium strain DN11

    Energy Technology Data Exchange (ETDEWEB)

    Yuki Kasai; Yumiko Kodama; Yoh Takahata; Toshihiro Hoaki; Kazuya Watanabe [Marine Biotechnology Institute, Kamaishi (Japan)

    2007-09-15

    Azoarcus sp. strain DN11 is a denitrifying bacterium capable of benzene degradation under anaerobic conditions. The present study evaluated strain DN11 for its application to bioaugmentation of benzene-contaminated underground aquifers. Strain DN11 could grow on benzene, toluene, m-xylene, and benzoate as the sole carbon and energy sources under nitrate-reducing conditions, although o- and p-xylenes were transformed in the presence of toluene. Phenol was not utilized under anaerobic conditions. Kinetic analysis of anaerobic benzene degradation estimated its apparent affinity and inhibition constants to be 0.82 and 11 {mu}M, respectively. Benzene-contaminated groundwater taken from a former coal-distillation plant site in Aichi, Japan was anaerobically incubated in laboratory bottles and supplemented with either inorganic nutrients (nitrogen, phosphorus, and nitrate) alone, or the nutrients plus strain DN11, showing that benzene was significantly degraded only when DN11 was introduced. Denaturing gradient gel electrophoresis of PCR-amplified 16S rRNA gene fragments, and quantitative PCR revealed that DN11 decreased after benzene was degraded. Following the decrease in DN11 16S rRNA gene fragments corresponding to bacteria related to Owenweeksia hongkongensis and Pelotomaculum isophthalicum, appeared as strong bands, suggesting possible metabolic interactions in anaerobic benzene degradation. Results suggest that DN11 is potentially useful for degrading benzene that contaminates underground aquifers at relatively low concentrations. 50 refs., 6 figs., 1 tab.

  14. Cytoplasmic expression of a thermostable invertase from Thermotoga maritima in Lactococcus lactis.

    Science.gov (United States)

    Pek, Han Bin; Lim, Pei Yu; Liu, Chengcheng; Lee, Dong-Yup; Bi, Xuezhi; Wong, Fong Tian; Ow, Dave Siak-Wei

    2017-05-01

    To evaluate the secretory and cytoplasmic expression of a thermostable Thermogata maritima invertase in Lactococcus lactis. The thermostable invertase from T. maritima was cloned with and without the USP45 secretory peptide into the pNZ8148 vector for nisin-inducible expression in L. lactis. The introduction of an USP45 secretion peptide at the N-terminal of the enzyme led to a loss of protein solubility. Computational homology modeling and hydrophobicity studies indicated that the USP45 peptide exposes a stretch of hydrophobic amino acids on the protein surface resulting in lower solubility. Removal of the USP45 secretion peptide allowed a soluble and functional invertase to be expressed intracellularly in L. lactis. Immobilized metal affinity chromatography purification of the cell lysate with nickel-NTA gave a single protein band on SDS-PAGE, while E. coli-expressed invertase consistently co-purified with an additional band. The yields of the purified invertase from E. coli and L. lactis were 14.1 and 6.3 mg/l respectively. Invertase can be expressed in L. lactis and purified in a functional form. L. lactis is a suitable host for the production of food-grade invertase for use in the food and biotechnology industries.

  15. Genetically Modified Lactococcus lactis for Delivery of Human Interleukin-10 to Dendritic Cells

    Directory of Open Access Journals (Sweden)

    Inge L. Huibregtse

    2012-01-01

    Full Text Available Interleukin-10 (IL-10 plays an indispensable role in mucosal tolerance by programming dendritic cells (DCs to induce suppressor Th-cells. We have tested the modulating effect of L. lactis secreting human IL-10 (L.  lactisIL-10 on DC function in vitro. Monocyte-derived DC incubated with L.  lactisIL-10 induced effector Th-cells that markedly suppressed the proliferation of allogenic Th-cells as compared to L. lactis. This suppressive effect was only seen when DC showed increased CD83 and CD86 expression. Furthermore, enhanced production of IL-10 was measured in both L.  lactisIL-10-derived DC and Th-cells compared to L. lactis-derived DC and Th-cells. Neutralizing IL-10 during DC-Th-cell interaction and coculturing L.  lactisIL-10-derived suppressor Th-cells with allogenic Th-cells in a transwell system prevented the induction of suppressor Th-cells. Only 130 pg/mL of bacterial-derived IL-10 and 40 times more exogenously added recombinant human IL-10 were needed during DC priming for the generation of suppressor Th-cells. The spatially restricted delivery of IL-10 by food-grade bacteria is a promising strategy to induce suppressor Th-cells in vivo and to treat inflammatory diseases.

  16. Modeling Lactococcus lactis using a genome-scale flux model

    Directory of Open Access Journals (Sweden)

    Nielsen Jens

    2005-06-01

    Full Text Available Abstract Background Genome-scale flux models are useful tools to represent and analyze microbial metabolism. In this work we reconstructed the metabolic network of the lactic acid bacteria Lactococcus lactis and developed a genome-scale flux model able to simulate and analyze network capabilities and whole-cell function under aerobic and anaerobic continuous cultures. Flux balance analysis (FBA and minimization of metabolic adjustment (MOMA were used as modeling frameworks. Results The metabolic network was reconstructed using the annotated genome sequence from L. lactis ssp. lactis IL1403 together with physiological and biochemical information. The established network comprised a total of 621 reactions and 509 metabolites, representing the overall metabolism of L. lactis. Experimental data reported in the literature was used to fit the model to phenotypic observations. Regulatory constraints had to be included to simulate certain metabolic features, such as the shift from homo to heterolactic fermentation. A minimal medium for in silico growth was identified, indicating the requirement of four amino acids in addition to a sugar. Remarkably, de novo biosynthesis of four other amino acids was observed even when all amino acids were supplied, which is in good agreement with experimental observations. Additionally, enhanced metabolic engineering strategies for improved diacetyl producing strains were designed. Conclusion The L. lactis metabolic network can now be used for a better understanding of lactococcal metabolic capabilities and potential, for the design of enhanced metabolic engineering strategies and for integration with other types of 'omic' data, to assist in finding new information on cellular organization and function.

  17. Bifidobacterium Bacteremia: Clinical Characteristics and a Genomic Approach To Assess Pathogenicity

    Science.gov (United States)

    Hjerde, Erik; Cavanagh, Jorunn Pauline; Simonsen, Gunnar Skov; Klingenberg, Claus

    2017-01-01

    ABSTRACT Bifidobacteria are commensals that colonize the orogastrointestinal tract and rarely cause invasive human infections. However, an increasing number of bifidobacterial blood culture isolates has lately been observed in Norway. In order to investigate the pathogenicity of the Bifidobacterium species responsible for bacteremia, we studied Bifidobacterium isolates from 15 patients for whom cultures of blood obtained from 2013 to 2015 were positive. We collected clinical data and analyzed phenotypic and genotypic antibiotic susceptibility. All isolates (11 Bifidobacterium longum, 2 B. breve, and 2 B. animalis isolates) were subjected to whole-genome sequencing. The 15 patients were predominantly in the extreme lower or upper age spectrum, many were severely immunocompromised, and 11 of 15 had gastrointestinal tract-related conditions. In two elderly patients, the Bifidobacterium bacteremia caused a sepsis-like picture, interpreted as the cause of death. Most bifidobacterial isolates had low MICs (≤0.5 mg/liter) to beta-lactam antibiotics, vancomycin, and clindamycin and relatively high MICs to ciprofloxacin and metronidazole. We performed a pangenomic comparison of invasive and noninvasive B. longum isolates based on 65 sequences available from GenBank and the sequences of 11 blood culture isolates from this study. Functional annotation identified unique genes among both invasive and noninvasive isolates of Bifidobacterium. Phylogenetic clusters of invasive isolates were identified for a subset of the B. longum subsp. longum isolates. However, there was no difference in the number of putative virulence genes between invasive and noninvasive isolates. In conclusion, Bifidobacterium has an invasive potential in the immunocompromised host and may cause a sepsis-like picture. Using comparative genomics, we could not delineate specific pathogenicity traits characterizing invasive isolates. PMID:28490487

  18. The pyrimidine operon pyrRPB-carA from Lactococcus lactis

    DEFF Research Database (Denmark)

    Martinussen, Jan; Schallert, J.; Andersen, Birgit

    2001-01-01

    The four genes pyrR, pyrP, pyrB, and carA were found to constitute an operon in Lactococcus lactis subsp, lactis MG1363. The functions of the different genes were established by mutational analysis. The first gene in the operon is the pyrimidine regulatory gene, pyrR, which is responsible...

  19. EXPRESSION OF A CHITINASE GENE FROM SERRATIA-MARCESCENS IN LACTOCOCCUS-LACTIS AND LACTOBACILLUS-PLANTARUM

    NARCIS (Netherlands)

    BRURBERG, MB; HAANDRIKMAN, AJ; LEENHOUTS, KJ; VENEMA, G; NES, IF

    1994-01-01

    A chitinase gene from the Gram-negative bacterium Serratia marcescens BJL200 was cloned in Lactococcus lactis subsp. lactis MG1363 and in the silage inoculum strain Lactobacillus plantarum E19b. The chitinase gene was expressed as an active enzyme at a low level in Lactococcus lactis, when cloned in

  20. Immunostimulatory effect of faecal Bifidobacterium species of breast-fed and formula-fed infants in a PBMC/CaCO-2 coculture system

    OpenAIRE

    Pozo Rubio, Tamara; Mujico, Jorge R.; Marcos, Ascensión; Puertollano, E; Nadal, Inmaculada; Sanz, Yolanda; Nova, Esther

    2011-01-01

    Bifidobacterium spp. typical of the human intestinal microbiota are believed to influence the balance of immune responses in the intestinal mucosa. Aim: To investigate the effect of different bifidobacterial species and mixtures of them in in vitro experiments with PBMCs and CaCo-2 cells. Methods: Bifidobacterium adolescentis; Bifidobacterium angulatum; Bifidobacterium breve; Bifidobacterium catenulatum; Bifidobacterium infantis; Bifidobacterium longum; and two combinations of these bif...

  1. Production of recombinant peanut allergen Ara h 2 using Lactococcus lactis

    DEFF Research Database (Denmark)

    Glenting, J.; Poulsen, Lars K.; Kato, K.

    2007-01-01

    lactis is an attractive microorganism for use in the production of protein therapeutics. L. lactis is considered food grade, free of endotoxins, and is able to secrete the heterologous product together with few other native proteins. Hypersensitivity to peanut represents a serious allergic problem. Some...... of the major allergens in peanut have been described. However, for therapeutic usage more information about the individual allergenic components is needed. In this paper we report recombinant production of the Ara h 2 peanut allergen using L. lactis. Results: A synthetic ara h 2 gene was cloned into an L...

  2. The effect of nisin from Lactococcus lactis subsp. lactis on refrigerated patin fillet quality

    Science.gov (United States)

    Adilla, S. N.; Utami, R.; Nursiwi, A.; Nurhartadi, E.

    2017-04-01

    The effect of nisin from Lactococcus lactis subsp. lactis with spraying method application on quality of patin fillet during refrigerated storage (4±1°C) was investigated. The quality of patin fillet based on total plate count (TPC), pH, TVB-N, and TBA values during 16 days at 4±1°C. Completely Randomized Design (CDR) was used in one factor (nisin activity) at 0 IU/ml, 500 IU/ml, 1000 IU/ml, and 2000 IU/ml. The observation was done at 0, 4th, 8th, 12th, and 16th days of storage. The result showed that variation of nisin activity significantly affected the quality of fillet according to TPC, pH, and TVB-N values, however no significant difference on the obtained of TBA value. Nisin in 500 IU/ml, 1000 IU/ml, and 2000 IU/ml could extend the shelf-life of fillet until 4th, 8th, and 12th days respectively based on standard in all parameters.

  3. High-Resolution Amplified Fragment Length Polymorphism Typing of Lactococcus lactis Strains Enables Identification of Genetic Markers for Subspecies-Related Phenotypes▿

    Science.gov (United States)

    Kütahya, Oylum Erkus; Starrenburg, Marjo J. C.; Rademaker, Jan L. W.; Klaassen, Corné H. W.; van Hylckama Vlieg, Johan E. T.; Smid, Eddy J.; Kleerebezem, Michiel

    2011-01-01

    A high-resolution amplified fragment length polymorphism (AFLP) methodology was developed to achieve the delineation of closely related Lactococcus lactis strains. The differentiation depth of 24 enzyme-primer-nucleotide combinations was experimentally evaluated to maximize the number of polymorphisms. The resolution depth was confirmed by performing diversity analysis on 82 L. lactis strains, including both closely and distantly related strains with dairy and nondairy origins. Strains clustered into two main genomic lineages of L. lactis subsp. lactis and L. lactis subsp. cremoris type-strain-like genotypes and a third novel genomic lineage rooted from the L. lactis subsp. lactis genomic lineage. Cluster differentiation was highly correlated with small-subunit rRNA homology and multilocus sequence analysis (MLSA) studies. Additionally, the selected enzyme-primer combination generated L. lactis subsp. cremoris phenotype-specific fragments irrespective of the genotype. These phenotype-specific markers allowed the differentiation of L. lactis subsp. lactis phenotype from L. lactis subsp. cremoris phenotype strains within the same L. lactis subsp. cremoris type-strain-like genomic lineage, illustrating the potential of AFLP for the generation of phenotype-linked genetic markers. PMID:21666014

  4. Membrane Protein Production in Lactococcus lactis for Functional Studies.

    Science.gov (United States)

    Seigneurin-Berny, Daphne; King, Martin S; Sautron, Emiline; Moyet, Lucas; Catty, Patrice; André, François; Rolland, Norbert; Kunji, Edmund R S; Frelet-Barrand, Annie

    2016-01-01

    Due to their unique properties, expression and study of membrane proteins in heterologous systems remains difficult. Among the bacterial systems available, the Gram-positive lactic bacterium, Lactococcus lactis, traditionally used in food fermentations, is nowadays widely used for large-scale production and functional characterization of bacterial and eukaryotic membrane proteins. The aim of this chapter is to describe the different possibilities for the functional characterization of peripheral or intrinsic membrane proteins expressed in Lactococcus lactis.

  5. Plasmid-mediated UV-protection in Streptococcus lactis

    Energy Technology Data Exchange (ETDEWEB)

    Chopin, M.C.; Rouault, A. (Institut National de la Recherche Agronomique, Rennes (France). Lab. de Recherches de Technologie Laitiere); Moillo-Batt, A. (Institut National de la Sante et de la Recherche Medicale (INSERM), Hopital de Pontchaillon, 35 - Rennes (France))

    1985-02-01

    Streptococcus lactis strain IL594 contains 9 plasmids, designated pIL1 to pIL9. On the basis of protoplast-induced curing experiments the authors showed that derivatives containing pIL7 were resistant to UV-irradiation while derivatives lacking pIL7 were sensitive. The pIL7-determined UV-protection was confirmed by co-transfer of the plasmid and of the character into a plasmid-free derivative of S. lactis IL594. Moreover, prophage induction required higher UV-fluence in this derivative carrying pIL7 than in the plasmid-free strain. This is the first report of a plasmid-mediated UV-protection in group N streptococci.

  6. Plasmid-mediated UV-protection in Streptococcus lactis

    International Nuclear Information System (INIS)

    Chopin, M.-C.; Rouault, A.

    1985-01-01

    Streptococcus lactis strain IL594 contains 9 plasmids, designated pIL1 to pIL9. On the basis of protoplast-induced curing experiments the authors showed that derivatives containing pIL7 were resistant to UV-irradiation while derivatives lacking pIL7 were sensitive. The pIL7-determined UV-protection was confirmed by cotransfer of the plasmid and of the character into a plasmid-free derivative of S. lactis IL594. Moreover, prophage induction required higher UV-fluence in this derivative carrying pIL7 than in the plasmid-free strain. This is the first report of a plasmid-mediated UV-protection in group N streptococci. (orig.)

  7. Microbes of fermented kefir-like using combination of kefir grains and Bifidobacterium longum

    Directory of Open Access Journals (Sweden)

    Sri Usmiati

    2005-03-01

    Full Text Available The objectives of research were to find out physico-chemical characters and to detect flavor volatile compound of kefir-like. Material used was skim milk TS 9.5% which was heated at 85oC for 30 minutes and cooled at 22oC before innoculation of the starter. Microorganisms used were (a Lactobacillus acidophilus P155110, (b Lactobacillus delbrueckii subsp. Bulgaricus NCIMB 11778, (c Lactococcus lactis P155610, (d Leuconostoc mesenteroides subsp. dextranicum NCIMB 3350, (e Acetobacter aceti P154810, (f Bifidobacterium longum BF1, and (g Saccharomyces cerevisiae P156252. The treatments consist of P1 = without (b; P2 = without (a; and P3= used (a until (g. The physico-chemical characters identified were lactic acid and lactose percentages, pH, viscosity, organoleptic test for intensity of kefir-like sensory attributes. Results indicated that B. longum was potential bacterium use for starter combination on kefir-like making. The use starter P1 combination has high acidity and viscosity, low pH and lactose percentage, and high intensity on attribute creamy-white color, soft and curdle consistency, and kefir specific aroma on kefir-like. Volatile compound acid group were dominate by high acidity character on kefir-like resulted from starter P1 combination. Compound of 3-hydroxi-2-butanone (acetoin was affecting butter-like of P3 character. This compound resulted from which is a character of fermented milk flavor was not detected on P1 kefir-like.

  8. Bifidobacterium mongoliense sp. nov., from airag, a traditional fermented mare's milk product from Mongolia.

    Science.gov (United States)

    Watanabe, Koichi; Makino, Hiroshi; Sasamoto, Masae; Kudo, Yuko; Fujimoto, Junji; Demberel, Shirchin

    2009-06-01

    Two novel micro-organisms, designated strains YIT 10443(T) and YIT 10738, were isolated from airag, a traditional fermented mare's milk from Mongolia. The two strains were Gram-positive-staining, non-motile, asporogenous, catalase-negative, facultatively anaerobic rods of various shapes. Comparative analyses of 16S rRNA and ClpC ATPase (clpC) gene sequences and the presence of fructose-6-phosphate phosphoketolase (F6PPK) demonstrated that the novel strains were members of the genus Bifidobacterium. On the basis of 16S rRNA gene sequence similarity, the type strains of Bifidobacterium minimum (96.6 %) and Bifidobacterium psychraerophilum (95.7 %) were the closest neighbours of the novel strains, and DNA-DNA reassociation values with these strains were found to be lower than 15 %. The phenotypic and genotypic features demonstrated that the two strains represent a single, novel Bifidobacterium species, for which the name Bifidobacterium mongoliense sp. nov. is proposed. The type strain is YIT 10443(T) (=JCM 15461(T) =DSM 21395(T)).

  9. The impact of selected strains of probiotic bacteria on metabolite formation in set yoghurt

    NARCIS (Netherlands)

    Settachaimongkon, S.; Nout, M.J.R.; Antunes Fernandes, E.C.; Hooijdonk, van A.C.M.; Zwietering, M.H.; Smid, E.J.; Valenberg, van H.J.F.

    2014-01-01

    The influence of Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp. lactis BB12 in cofermentation with traditional starters on metabolite formation in set yoghurt was evaluated. Microbial activity during fermentation and refrigerated storage was investigated by monitoring bacterial

  10. From Streptococcus lactis to Lactococcus lactis: A qualitative and quantitative analysis of the scope of research undertaken around a microbial concept

    OpenAIRE

    Yann Demarigny; Virginie Soldat; Laetitia Gemelas

    2015-01-01

    The lactic acid bacterium Lactococcus lactis, formerly named Streptococcus lactis, has been known and used for many years, even before its re-affiliation in 1985. The number of published papers featuring one of the two names, either in the title or in the key words, currently stands at more than 2,900. From 1945 to 2014, a bibliometric analysis of the evolution of this bacterium allowed us to identify three phases we have called 1, the “exploratory period” (or the “US period” if we refer to t...

  11. Vaccination against Staphylococcus aureus experimental endocarditis using recombinant Lactococcus lactis expressing ClfA or FnbpA.

    Science.gov (United States)

    Veloso, Tiago Rafael; Mancini, Stefano; Giddey, Marlyse; Vouillamoz, Jacques; Que, Yok-Ai; Moreillon, Philippe; Entenza, José Manuel

    2015-07-09

    Staphylococcus aureus is a major cause of serious infections in humans and animals and a vaccine is becoming a necessity. Lactococcus lactis is a non-pathogenic bacterium that can be used as a vector for the delivery of antigens. We investigated the ability of non-living L. lactis heterologously expressing S. aureus clumping factor A (ClfA) and fibronectin-binding protein A (FnbpA), alone or together, to elicit an immune response in rats and protect them from S. aureus experimental infective endocarditis (IE). L. lactis ClfA was used for immunization against S. aureus Newman (expressing ClfA but not FnbpA), while L. lactis ClfA, L. lactis FnbpA, as well as L. lactis ClfA/FnbpA, were used against S. aureus P8 (expressing ClfA and FnbpA). Vaccination of rats with L. lactis ClfA elicited antibodies that inhibited binding of S. aureus Newman to fibrinogen, triggered the production of IL-17A and conferred protection to 13/19 (68%) of the animals from IE (Plactis ClfA, L. lactis FnbpA or L. lactis ClfA/FnbpA also produced antibodies against the target proteins, but these did not prevent binding of S. aureus P8 to fibrinogen or fibronectin and did not protect animals against S. aureus P8 IE. Moreover, immunization with constructs containing FnbpA did not increase IL-17A production. These results indicate that L. lactis is a valuable antigen delivery system able to elicit efficient humoral and cellular responses. However, the most appropriate antigens affording protection against S. aureus IE are yet to be elucidated. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. The Efficacy of the Use of Probiotic Therapy in Young Children with Food Allergy

    Directory of Open Access Journals (Sweden)

    O.S. Ivakhnenko

    2013-09-01

    Full Text Available The purpose of this study — to evaluate the efficacy of inclusion of probiotics Bifidobacterium lactis BB-12 (1 × 109 CFU and Streptococcus thermophilus TH-4 (1 × 108 CFU in the compbined treatment of atopic dermatitis in infants on the background of food allergy to cow’s milk protein. The study revealed that the addition of probiotics Bifidobacterium lactis BB-12 (1 × 109 CFU, and Streptococcus thermophilus TH-4 (1 × 108 CFU for 4 weeks in infants with atopic dermatitis and proved allergy to cow’s milk protein against the elimination diet and basic treatment improves the clinical course of the disease, has a significantly positive impact on the clinical course of atopic dermatitis, reduces gastrointestinal symptoms of food allergies and has little influence on the occurrence of obstructive bronchitis.

  13. Unleashing Natural Competence in Lactococcus lactis by Induction of the Competence Regulator ComX

    Science.gov (United States)

    Mulder, Joyce; Wels, Michiel; Kuipers, Oscar P.; Bron, Peter A.

    2017-01-01

    ABSTRACT In biotechnological workhorses like Streptococcus thermophilus and Bacillus subtilis, natural competence can be induced, which facilitates genetic manipulation of these microbes. However, in strains of the important dairy starter Lactococcus lactis, natural competence has not been established to date. However, in silico analysis of the complete genome sequences of 43 L. lactis strains revealed complete late competence gene sets in 2 L. lactis subsp. cremoris strains (KW2 and KW10) and at least 10 L. lactis subsp. lactis strains, including the model strain IL1403 and the plant-derived strain KF147. The remainder of the strains, including all dairy isolates, displayed genomic decay in one or more of the late competence genes. Nisin-controlled expression of the competence regulator comX in L. lactis subsp. lactis KF147 resulted in the induction of expression of the canonical competence regulon and elicited a state of natural competence in this strain. In contrast, comX expression in L. lactis NZ9000, which was predicted to encode an incomplete competence gene set, failed to induce natural competence. Moreover, mutagenesis of the comEA-EC operon in strain KF147 abolished the comX-driven natural competence, underlining the involvement of the competence machinery. Finally, introduction of nisin-inducible comX expression into nisRK-harboring derivatives of strains IL1403 and KW2 allowed the induction of natural competence in these strains also, expanding this phenotype to other L. lactis strains of both subspecies. IMPORTANCE Specific bacterial species are able to enter a state of natural competence in which DNA is taken up from the environment, allowing the introduction of novel traits. Strains of the species Lactococcus lactis are very important starter cultures for the fermentation of milk in the cheese production process, where these bacteria contribute to the flavor and texture of the end product. The activation of natural competence in this industrially

  14. Simultaneous lactic acidification and coagulation by using recombinant Lactococcus lactis strain.

    Science.gov (United States)

    Raftari, M; Ghafourian, S; Abu Bakar, F

    2017-04-01

    This study was an attempt to create a novel milk clotting procedure using a recombinant bacterium capable of milk coagulation. The Rhizomucor pusillus proteinase (RPP) gene was sub-cloned into a pALF expression vector. The recombinant pALF-RPP vector was then electro-transferred into Lactococcus lactis. Finally, the milk coagulation ability of recombinant L. lactis carrying a RPP gene was evaluated. Nucleotide sequencing of DNA insertion from the clone revealed that the RPP activity corresponded to an open reading frame consisting of 1218 bp coding for a 43·45 kDa RPP protein. The RPP protein assay results indicated that the highest RPP enzyme expression with 870 Soxhlet units (SU) per ml and 7914 SU/OD were obtained for cultures which were incubated at pH 5·5 and 30°C. Interestingly, milk coagulation was observed after 205 min of inoculating milk with recombinant L. lactis carrying the RPP gene. The recombinant L. lactis carrying RPP gene has the ability to function as a starter culture for acidifying and subsequently coagulating milk by producing RPP as a milk coagulant agent. Creating a recombinant starter culture bacterium that is able to coagulate milk. It is significant because the recombinant L. lactis has the ability to work as a starter culture and milk coagulation agent. © 2016 The Society for Applied Microbiology.

  15. Improvement of the respiration efficiency of Lactococcus lactis by decreasing the culture pH.

    Science.gov (United States)

    Shi, Weijia; Li, Yu; Gao, Xueling; Fu, Ruiyan

    2016-03-01

    The growth characteristics and intracellular hemin concentrations of Lactococcus lactis grown under different culture pH and aeration conditions were examined to investigate the effect of culture pH on the respiration efficiency of L. lactis NZ9000 (pZN8148). Cell biomass and biomass yield of L. lactis grown with 4 μg hemin/ml and O2 were higher than those without aeration when the culture pH was controlled at 5-6.5. The culture pH affected the respiratory efficiency in the following order of pH: 5 > 5.5 > 6 > 6.5; the lag phase increased as the culture pH decreased. Hemin accumulation was sensitive to culture pH. Among the four pH conditions, pH 5.5 was optimal for hemin accumulation in the cells. The highest intracellular hemin level in L. lactis resting cells incubated at different pH saline levels (5-6.5) was at pH 5.5. The respiration efficiency of L. lactis under respiration-permissive conditions increases markedly as the culture pH decreases. These results may help develop high cell-density L. lactis cultures. Thus, this microorganism may be used for industrial applications.

  16. EST Table: DN237607 [KAIKOcDNA[Archive

    Lifescience Database Archive (English)

    Full Text Available tatin; Flags: Precursor gb|AAT40571.1| myostatin [Aepyceros melampus] 10/09/03 49 %/132 aa FBpp0273825|DpseG...ef|XP_966819.1| PREDICTED: similar to myostatin [Tribolium castaneum] DN237607 BmP ...

  17. Lactococcus lactis subsp. tructae subsp. nov. isolated from the intestinal mucus of brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss).

    Science.gov (United States)

    Pérez, Tania; Balcázar, José Luis; Peix, Alvaro; Valverde, Angel; Velázquez, Encarna; de Blas, Ignacio; Ruiz-Zarzuela, Imanol

    2011-08-01

    The species Lactococcus lactis currently includes three subspecies; L. lactis subsp. lactis and L. lactis subsp. cremoris, isolated from milk sources, and L. lactis subsp. hordniae, isolated from the leafhopper Hordnia circellata. In this study, three strains, designated L105(T), I3 and L101, were isolated from the intestinal mucus of brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss). These strains were closely related to members of the species Lactococcus lactis. Strain L105(T) showed 99.4 % 16S rRNA gene sequence similarity to that of the type strains L. lactis subsp. lactis NCDO 604(T) and L. lactis subsp. hordniae NCDO 2181(T) and showed 99.9 % similarity to the type strain Lactococcus lactis subsp. cremoris NCDO 607(T). Analysis of two housekeeping genes, rpoB and recA, confirmed the close relationship between the novel strains and L. lactis subsp. cremoris with similarities of 99.3 and 99.7 %, respectively. The three strains could, however, be differentiated from their closest relatives on the basis of several phenotypic characteristics, as was the case for L. lactis subsp. lactis and L. lactis subsp. hordniae, which were also closely related on the basis of 16S rRNA, rpoB and recA gene sequence similarities. The strains isolated in this study represent a new subspecies, for which the name Lactococcus lactis subsp. tructae subsp. nov. is proposed. The type strain is L105(T) ( = LMG 24662(T)  = DSM 21502(T)).

  18. Expression of Helicobacter pylori hspA Gene in Lactococcus lactis NICE System and Experimental Study on Its Immunoreactivity

    Directory of Open Access Journals (Sweden)

    Xiao-Juan Zhang

    2015-01-01

    Full Text Available Aim. The aim of this study was to develop an oral Lactococcus lactis (L. lactis vaccine against Helicobacter pylori (H. pylori. Methods. After L. lactis NZ3900/pNZ8110-hspA was constructed, growth curves were plotted to study whether the growth of recombinant L. lactis was affected after hspA was cloned into L. lactis and whether the growth of empty bacteria, empty plasmid bacteria, and recombinant L. lactis was affected by different concentrations of Nisin; SDS-PAGE and Western blot were adopted, respectively, to detect the HspA expressed by recombinant L. lactis and its immunoreactivity. Results. There was no effect observed from the growth curve after exogenous gene hspA was cloned into L. lactis NZ3900; different concentrations of Nisin did not affect the growth of NZ3900 and NZ3900/pNZ8110, while different concentrations of Nisin inhibited the growth of NZ3900/pNZ8110-hspA except 10 ng/mL Nisin. No HspA strip was observed from SDS-PAGE. Western blot analysis showed that HspA expressed by recombinant bacteria had favorable immunoreactivity. Conclusion. The growth of recombinant L. lactis was suppressed even though a small amount of HspA had been induced to express. Therefore recombinant L. lactis only express HspA which was not suitable to be oral vaccine against Helicobacter pylori.

  19. Lactococcus lactis subsp. lactis infection in Bester sturgeon, a cultured hybrid of Huso huso × Acipenser ruthenus, in Taiwan.

    Science.gov (United States)

    Chen, Ming-Hui; Hung, Shao-Wen; Shyu, Ching-Lin; Lin, Cheng-Chung; Liu, Pan-Chen; Chang, Chen-Hsuan; Shia, Wei-Yau; Cheng, Ching-Fu; Lin, Shiun-Long; Tu, Ching-Yu; Lin, Yu-Hsing; Wang, Way-Shyan

    2012-10-01

    Approximately 5300 hybrid sturgeons with an average body weight of 600-800 g were farmed in 3 round tankers measuring 3m in diameter each containing 28,000 L of aerated groundwater. According to the owner's description, the diseased fish had anorexia, pale body color, and reddish spots on the abdomen. The morbidity and lethality rates in this outbreak were about 70% (3706/5300) and 100% (3706/3706), respectively. The clinical examination revealed enteritis, enlarged abdomen, and rapid respiration rate. The gross findings revealed a volume of about 4 mL of ascites. The histopathological examination showed multiple massive, hemorrhagic or coagulative necrotic foci in the liver and spleen. Furthermore, there was diffuse infiltration of glycogen in hepatic cells, and a few polymorphonuclear and mononuclear leucocytes were observed surrounding the spleen. Some bacterial clumps were noted around the necrotic foci. We also observed that there was moderate to severe, acute, multifocal, coagulative necrosis in the renal parenchyma, with some necrotic foci present beneath the margin of the kidney. Additionally, multifocal, coagulative necrosis was found in the pancreas. Results of microbiologic examinations, including biochemical characteristics, PCR amplification of 16S rRNA gene, sequencing and comparison, and phylogenetic analysis, revealed the pathogen of this infection was Lactococcus lactis subsp. lactis, and based on the results of an antimicrobial agent sensitivity test the bacterium was only sensitive to ampicillin and florfenicol. Additionally, results of in vivo experimental infections in hybrid tilapia showed that 1×10(8) and 1×10(9) CFU/mL of our isolate caused death in all fish and LD(50) values ranged from 10(2) to 10(5) CFU/mL. To the best of the authors' knowledge, this is the first reported case of Lactococcus lactis subsp. lactis infection in hybrid sturgeon. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Transcriptome analysis of Lactococcus lactis subsp. lactis during milk acidification as affected by dissolved oxygen and the redox potential.

    Science.gov (United States)

    Larsen, Nadja; Moslehi-Jenabian, Saloomeh; Werner, Birgit Brøsted; Jensen, Maiken Lund; Garrigues, Christel; Vogensen, Finn Kvist; Jespersen, Lene

    2016-06-02

    Performance of Lactococcus lactis as a starter culture in dairy fermentations depends on the levels of dissolved oxygen and the redox state of milk. In this study the microarray analysis was used to investigate the global gene expression of L. lactis subsp. lactis DSM20481(T) during milk acidification as affected by oxygen depletion and the decrease of redox potential. Fermentations were carried out at different initial levels of dissolved oxygen (dO2) obtained by milk sparging with oxygen (high dO2, 63%) or nitrogen (low dO2, 6%). Bacterial exposure to high initial oxygen resulted in overexpression of genes involved in detoxification of reactive oxygen species (ROS), oxidation-reduction processes, biosynthesis of trehalose and down-regulation of genes involved in purine nucleotide biosynthesis, indicating that several factors, among them trehalose and GTP, were implicated in bacterial adaptation to oxidative stress. Generally, transcriptional changes were more pronounced during fermentation of oxygen sparged milk. Genes up-regulated in response to oxygen depletion were implicated in biosynthesis and transport of pyrimidine nucleotides, branched chain amino acids and in arginine catabolic pathways; whereas genes involved in salvage of nucleotides and cysteine pathways were repressed. Expression pattern of genes involved in pyruvate metabolism indicated shifts towards mixed acid fermentation after oxygen depletion with production of specific end-products, depending on milk treatment. Differential expression of genes, involved in amino acid and pyruvate pathways, suggested that initial oxygen might influence the release of flavor compounds and, thereby, flavor development in dairy fermentations. The knowledge of molecular responses involved in adaptation of L. lactis to the shifts of redox state and pH during milk fermentations is important for the dairy industry to ensure better control of cheese production. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Cloning in Streptococcus lactis of plasmid-mediated UV resistance and effect on prophage stability

    International Nuclear Information System (INIS)

    Chopin, M.C.; Chopin, A.; Rouault, A.; Simon, D.

    1986-01-01

    Plasmid pIL7 (33 kilobases) from Streptococcus lactis enhances UV resistance and prophage stability. A 5.4-kilobase pIL7 fragment carrying genes coding for both characters was cloned into S. lactis, using plasmid pHV1301 as the cloning vector. The recombinant plasmid was subsequently transferred to three other S. lactis strains by transformation or protoplast fusion. Cloned genes were expressed in all tested strains

  2. A convenient and reproducible method to genetically transform bacteria of the genus Bifidobacterium

    NARCIS (Netherlands)

    Argnani, A.; Leer, R.J.; Luijk, N. van; Pouwels, P.H.

    1996-01-01

    A protocol was developed for the introduction of foreign plasmid DNA into various Bifidobacterium strains. The method, which is applicable to all Bifidobacterium species tested so far, is based on electroporation of bacteria made competent by preincubation in electroporation buffer for several hours

  3. Immune effects of the probiotic Bifidobacterium breve

    NARCIS (Netherlands)

    Ezendam J; van Loveren H; TOX

    2007-01-01

    Bifidobacterium breve, een probiotische bacterie, heeft gunstige effecten op zowel allergieen als autoimmuniteit - een afweerreactie op lichaamseigen bestanddelen - bij proefdieren. Probiotica worden in reclameboodschappen ook wel 'goede bacterien' genoemd. Fabrikanten claimen een positief effect

  4. Rewiring Lactococcus lactis for Ethanol Production

    DEFF Research Database (Denmark)

    Solem, Christian; Dehli, Tore Ibsen; Jensen, Peter Ruhdal

    2013-01-01

    to redirect the metabolism of LAB model organism Lactococcus lactis toward ethanol production. Codon-optimized Zymomonas mobilis pyruvate decarboxylase (PDC) was introduced and expressed from synthetic promoters in different strain backgrounds. In the wild-type L. lactis strain MG1363 growing on glucose, only...... small amounts of ethanol were obtained after introducing PDC, probably due to a low native alcohol dehydrogenase activity. When the same strains were grown on maltose, ethanol was the major product and lesser amounts of lactate, formate, and acetate were formed. Inactivating the lactate dehydrogenase...... genes ldhX, ldhB, and ldh and introducing codon-optimized Z. mobilis alcohol dehydrogenase (ADHB) in addition to PDC resulted in high-yield ethanol formation when strains were grown on glucose, with only minor amounts of by-products formed. Finally, a strain with ethanol as the sole observed...

  5. Bifidobacterium animalis AHC7 protects against pathogen-induced NF-kappaB activation in vivo

    LENUS (Irish Health Repository)

    O'Mahony, David

    2010-12-22

    Abstract Background Bifidobacteria and lactobacilli are among the early and important colonizers of the gastrointestinal tract and are generally considered to be part of a normal, healthy microbiota. It is believed that specific strains within the microbiota can influence host immune-reactivity and may play a role in protection from infection and aberrant inflammatory activity. One such strain, Bifidobacterium animalis AHC7, has been previously shown to protect against Salmonella typhimurium infection in mice and helps resolve acute idiopathic diarrhea in dogs. The aim of this study was to investigate the potential molecular and cellular mechanisms underpinning the Bifidobacterium animalis AHC7 protective effect. Results Following 4 hours of infection with Salmonella typhimurium, NF-κB activation was significantly elevated in vivo in placebo and Enterococcus faecium-fed animals while Bifidobacterium animalis AHC7 consumption significantly attenuated the NF-κB response. In vitro anti-CD3\\/CD28 stimulated Peyer\\'s patch cells secreted significantly less TNF-α and IFN-γ following Bifidobacterium animalis AHC7 consumption. Stimulated cells released more IL-12p70 but this difference did not reach statistical significance. No alteration in mucosal IL-6, IL-10 or MCP-1 levels were observed. No statistically significant change in the cytokine profile of mesenteric lymph node cells was noted. In vitro, Bifidobacterium animalis AHC7 was bound by dendritic cells and induced secretion of both IL-10 and IL-12p70. In addition, co-culture of CD4+ T cells with Bifidobacterium animalis AHC7-stimulated dendritic cells resulted in a significant increase in CD25+Foxp3+ T cell numbers. Conclusion Bifidobacterium animalis AHC7 exerts an anti-inflammatory effect via the attenuation of pro-inflammatory transcription factor activation in response to an infectious insult associated with modulation of pro-inflammatory cytokine production within the mucosa. The cellular mechanism

  6. Generation of a membrane potential by Lactococcus lactis through aerobic electron transport

    NARCIS (Netherlands)

    Brooijmans, R. J. W.; Poolman, B.; Schuurman-Wolters, G. K.; de Vos, W. M.; Hugenholtz, J.

    Lactococcus lactis, a facultative anaerobic lactic acid bacterium, is known to have an increased growth yield when grown aerobically in the presence of heme. We have now established the presence of a functional, proton motive force-generating electron transfer chain (ETC) in L. lactis under these

  7. Elucidating Flux Regulation of the Fermentation Modes of Lactococcus lactis:A Mutlilevel Study

    OpenAIRE

    Chan, Siu Hung Joshua; Solem, Christian; Jensen, Peter Ruhdal

    2014-01-01

    De mange års anvendelse af mælkesyrebakterien Lactococcus lactis (L. lactis) indenfor mejeriindustrien, har været medvirkende til at L. lactis er blevet en af de mest velkarakteriserede bakterier. Denne Gram positive bakterie, som har et lavt GC indhold, har en relativt simpel metabolisme og er let at modificere genetisk. Dette har gjort den til et attraktivt mål for ”metabolic engineering”, bl.a. med henblik på produktion af non-food relaterede kemikalier. Derudover har den status som den fø...

  8. Lactococcus lactis KR-050L inhibit IL-6/STAT3 activation.

    Science.gov (United States)

    Hwang, J T; Jang, H-J; Kim, J H; Park, C S; Kim, Y; Lim, C-H; Lee, S W; Rho, M-C

    2017-05-01

    The purpose of this study was to investigate IL-6/STAT3 inhibitory activity using lactic acid bacteria (LABs) isolated from Gajuknamu kimchi. Six LABs were isolated from Gajuknamu kimchi and identified through 16S rRNA sequencing. Among them, the culture broth of Lactococcus lactis KR-050L inhibited IL-6-induced STAT3 luciferase activity. Fifteen compounds were isolated from the EtOAc extract of culture broth though column chromatography and preparative high-performance liquid chromatography, and they were identified as 2,5-diketopipperazine structures by spectroscopic analyses (MS, 1 H- and 13 C-NMR). They also showed inhibitory activities on IL-6-induced STAT3 activation, and showed the different in activity according to the presence of a phenylalanine residue, hydroxyl groups and isometric structure. The six new LABs isolated from Gajuknamu kimchi, and Lc. lactis KR-050L was selected as candidate IL-6/STAT3 inhibitors. The activity levels of 15 2,5-DKPs isolated from Lc. lactis KR-050L were verified. This study constitutes the first attempt to isolate various LABs from Gajuknamu kimchi and to discover IL-6/STAT3 inhibitors in the EtOAc extract of Lc. lactis KR-050L culture broth. Moreover, our data provide useful biochemical information regarding the commercialization of Lc. lactis isolated from Gajuknamu kimchi as an approach to use functional foods for the treatment of various diseases via IL-6/STAT3 activation. © 2017 The Society for Applied Microbiology.

  9. The curious case of SN 2011dn: A very peculiar type Ia supernova?

    Science.gov (United States)

    Rachubo, Alisa

    Type Ia supernovae (SNe Ia) are excellent cosmological distance indicators due to the uniformity in their light curves, which led to the major discovery of the accelerated expansion of the universe. However, SNe Ia are not so uniform as one may expect, as there are many peculiar SNe Ia that exhibit differences in their photometric and spectroscopic behavior from normal SNe Ia. One of the goals of supernova cosmology today is to produce a cleaner sample of SNe Ia without these peculiar SNe Ia. Here we consider SN 2011dn, a peculiar SN Ia candidate. In 2011, Salvo, et al. carried out a preliminary analysis of a subset of the data prescribed here, and identified spectral and photometric peculiarities in this object's evolution that warranted further analysis. Here, we present a complete re-reduction and reanalysis of B, V,R, and I photometry of SN 2011dn obtained at Mount Laguna Observatory, spanning from 7 days before maximum light in B to 88 days past maximum light. In addition, we also consider total flux spectra from 9 days before maximum light to 4 days after maximum light, along with ultraviolet (UV) photometry obtained with the Swift telescope. From SN 2011dn's optical spectra, we find that SN 2011dn most closely resembles a SN 1991T-like type Ia supernova ('91T-like SN Ia). Such SNe Ia are typically more luminous than normal SNe Ia, and possess broader (i.e., they decline less rapidly than normal from maximum light) light curves. Their Deltam15(B) (drop in B magnitude 15 days after maximum light) are typically significantly less than the canonical value of 1.1, and can be as low as 0.8. In the earlier preliminary analysis, Salvo et al. measured a surprisingly high Deltam15(B) value for SN 2011dn, of ˜ 1.1. Since SN 2011dn was embedded in UGC 11501 (its host galaxy), however, it is possible that some of the light from the host galaxy was included in the photometric aperture, resulting in inaccurate photometric measurements. Here, in order to better isolate the

  10. Biotransformation of Tributyltin chloride by Pseudomonas stutzeri strain DN2

    Directory of Open Access Journals (Sweden)

    Dnyanada S. Khanolkar

    2014-12-01

    Full Text Available A bacterial isolate capable of utilizing tributyltin chloride (TBTCl as sole carbon source was isolated from estuarine sediments of west coast of India and identified as Pseudomonas stutzeri based on biochemical tests and Fatty acid methyl ester (FAME analysis. This isolate was designated as strain DN2. Although this bacterial isolate could resist up to 3 mM TBTCl level, it showed maximum growth at 2 mM TBTCl in mineral salt medium (MSM. Pseudomonas stutzeri DN2 exposed to 2 mM TBTCl revealed significant alteration in cell morphology as elongation and shrinkage in cell size along with roughness of cell surface. FTIR and NMR analysis of TBTCl degradation product extracted using chloroform and purified using column chromatography clearly revealed biotransformation of TBTCl into Dibutyltin dichloride (DBTCl2 through debutylation process. Therefore, Pseudomonas stutzeri strain DN2 may be used as a potential bacterial strain for bioremediation of TBTCl contaminated aquatic environmental sites.

  11. Biotransformation of Tributyltin chloride by Pseudomonas stutzeri strain DN2

    Science.gov (United States)

    Khanolkar, Dnyanada S.; Naik, Milind Mohan; Dubey, Santosh Kumar

    2014-01-01

    A bacterial isolate capable of utilizing tributyltin chloride (TBTCl) as sole carbon source was isolated from estuarine sediments of west coast of India and identified as Pseudomonas stutzeri based on biochemical tests and Fatty acid methyl ester (FAME) analysis. This isolate was designated as strain DN2. Although this bacterial isolate could resist up to 3 mM TBTCl level, it showed maximum growth at 2 mM TBTCl in mineral salt medium (MSM). Pseudomonas stutzeri DN2 exposed to 2 mM TBTCl revealed significant alteration in cell morphology as elongation and shrinkage in cell size along with roughness of cell surface. FTIR and NMR analysis of TBTCl degradation product extracted using chloroform and purified using column chromatography clearly revealed biotransformation of TBTCl into Dibutyltin dichloride (DBTCl2) through debutylation process. Therefore, Pseudomonas stutzeri strain DN2 may be used as a potential bacterial strain for bioremediation of TBTCl contaminated aquatic environmental sites. PMID:25763027

  12. Fecal microbiota changes with the consumption of follow-up formulas containing Bifidobacterium spp. and/or galactooligosaccharides by rats and a follow-up infant formula containing Bifidobacterium spp. by human infants

    NARCIS (Netherlands)

    Perez-Conesa, D.; Lopez, G.; Ros, G.H.; Abellan, P.; Hartemink, R.

    2006-01-01

    Seven groups of rats were fed during 1 mo using 1 infant formula containing Bifidobacterium bifidum and Bifidobacterium longum, 3 infant formulas containing 4-galactosyllactose at 1.2%, 5.0%, and 10.0%, and 3 infant formulas containing both ingredients. During 3 periods, corresponding to day 8 to

  13. Generation of Dipeptidyl Peptidase-IV-Inhibiting Peptides from β-Lactoglobulin Secreted by Lactococcus lactis

    Directory of Open Access Journals (Sweden)

    Suguru Shigemori

    2014-01-01

    Full Text Available Previous studies showed that hydrolysates of β-lactoglobulin (BLG prepared using gastrointestinal proteases strongly inhibit dipeptidyl peptidase-IV (DPP-IV activity in vitro. In this study, we developed a BLG-secreting Lactococcus lactis strain as a delivery vehicle and in situ expression system. Interestingly, trypsin-digested recombinant BLG from L. lactis inhibited DPP-IV activity, suggesting that BLG-secreting L. lactis may be useful in the treatment of type 2 diabetes mellitus.

  14. Expression of Six Peptidases from Lactobacillus helveticus in Lactococcus lactis

    OpenAIRE

    Luoma, Susanna; Peltoniemi, Kirsi; Joutsjoki, Vesa; Rantanen, Terhi; Tamminen, Marja; Heikkinen, Inka; Palva, Airi

    2001-01-01

    For development of novel starter strains with improved proteolytic properties, the ability of Lactococcus lactis to produce Lactobacillus helveticus aminopeptidase N (PepN), aminopeptidase C (PepC), X-prolyl dipeptidyl aminopeptidase (PepX), proline iminopeptidase (PepI), prolinase (PepR), and dipeptidase (PepD) was studied by introducing the genes encoding these enzymes into L. lactis MG1363 and its derivatives. According to Northern analyses and enzyme activity measurements, the L. helvetic...

  15. [The humoral immune response in mice induced by recombinant Lactococcus lactis expressing HIV-1 gag].

    Science.gov (United States)

    Zhao, Xiaofei; Zhang, Cairong; Liu, Xiaojuan; Ma, Zhenghai

    2014-11-01

    To analyze the humoral immune response induced by recombinant Lactococcus lactis expressing HIV-1 gag in mice immunized orally, intranasally, subcutaneously or in the combined way of above three. Fifty BALB/c mice were randomly divided into 5 groups, 10 mice per group. The mice were immunized consecutively three times at two week intervals with 10(9) CFU of recombinant Lactococcus lactis expressing gag through oral, intranasal, subcutaneous administration or the mix of them. The mice that were immunized orally with Lactococcus lactis containing PMG36e served as a control group. The sera of mice were collected before primary immunization and 2 weeks after each immunization to detect the gag specific IgG by ELISA. Compared with the control group, the higher titer of serum gag specific IgG was detected in the four groups immunized with recombinant Lactococcus lactis expressing gag, and it was the highest in the mixed immunization group (PLactococcus lactis expressing gag can induce humoral immune response in mice by oral, intranasal, subcutaneous injection or the mix of them, and the mixed immunization can enhance the immune effects of Lactococcus lactis vector vaccine.

  16. Simultaneous growth and metabolite production by yoghurt starters and probiotics: a metabolomics approach

    NARCIS (Netherlands)

    Settachaimongkon, S.

    2014-01-01

    The main objective of this research was to investigate the simultaneous growth and metabolite production by yoghurt starters and different probiotic strains, i.e. Lactobacillus rhamnosus GG, Bifidobacterium animalis subsp. lactis BB12 and Lactobacillus

  17. Study of physiological properties of some probiotics in multiple cultures with mesophilic lactic acid bacteria by Flora Danica Ch. Hansen commercial starter

    Directory of Open Access Journals (Sweden)

    DANIELA PARASCHIV

    2011-12-01

    Full Text Available The aim of this study was to establish the growth ability and stability of probiotic strains Lactobacillus acidophilus (commercial code La-5®, Lactobacillus casei ssp. paracasei (commercial code L. casei 431® and Bifidobacterium bifidus (commercial code BB-12® in multiple cultures with mesophilic lactic bacteria, Lactococcus lactis ssp. cremoris, Lactococcus lactis ssp. lactis, Lactococcus lactis ssp. diacetylactis and Leuconostoc mesenteroides spp. cremoris, as Flora Danica Chr. Hansen commercial starters. Under the controlled fermentative conditions described below, a good starter combination, for the high rate of cells multiplication and for the good viability during storage, was identified in the mixture of L. casei 431®, BB-12® and Flora Danica, in ratio of 1:1:1 (9 log CFU/mL for each starter culture.

  18. Analyses of the probiotic property and stress resistance-related genes of Lactococcus lactis subsp. lactis NCDO 2118 through comparative genomics and in vitro assays.

    Science.gov (United States)

    Oliveira, Letícia C; Saraiva, Tessália D L; Silva, Wanderson M; Pereira, Ulisses P; Campos, Bruno C; Benevides, Leandro J; Rocha, Flávia S; Figueiredo, Henrique C P; Azevedo, Vasco; Soares, Siomar C

    2017-01-01

    Lactococcus lactis subsp. lactis NCDO 2118 was recently reported to alleviate colitis symptoms via its anti-inflammatory and immunomodulatory activities, which are exerted by exported proteins that are not produced by L. lactis subsp. lactis IL1403. Here, we used in vitro and in silico approaches to characterize the genomic structure, the safety aspects, and the immunomodulatory activity of this strain. Through comparative genomics, we identified genomic islands, phage regions, bile salt and acid stress resistance genes, bacteriocins, adhesion-related and antibiotic resistance genes, and genes encoding proteins that are putatively secreted, expressed in vitro and absent from IL1403. The high degree of similarity between all Lactococcus suggests that the Symbiotic Islands commonly shared by both NCDO 2118 and KF147 may be responsible for their close relationship and their adaptation to plants. The predicted bacteriocins may play an important role against the invasion of competing strains. The genes related to the acid and bile salt stresses may play important roles in gastrointestinal tract survival, whereas the adhesion proteins are important for persistence in the gut, culminating in the competitive exclusion of other bacteria. Finally, the five secreted and expressed proteins may be important targets for studies of new anti-inflammatory and immunomodulatory proteins. Altogether, the analyses performed here highlight the potential use of this strain as a target for the future development of probiotic foods.

  19. Oral Administration of Recombinant Lactococcus lactis Expressing the Cellulase Gene Increases Digestibility of Fiber in Geese.

    Science.gov (United States)

    Zhou, Haizhu; Gao, Yunhang; Gao, Guang; Lou, Yujie

    2015-12-01

    Enhancing cellulose digestibility in animals is important for improving the utilization of forage, which can decrease the amount of food used in animal production. The aim of the present study was to achieve recombinant expression of the cellulase gene in Lactococcus lactis and evaluate the effects of oral administration of the recombinant L. lactis on fiber digestibility in geese. Cellulase (Cell) and green fluorescent protein (GFP) genes were cloned into a L. lactis expression vector (pNZ8149) to construct the recombinant expression plasmid (pNZ8149-GFP-Cell). Then, the recombinant expression plasmid was transformed into L. lactis (NZ3900) competent cells by electroporation to obtain recombinant L. lactis (pNZ8149-GFP-Cell/NZ3900) in which protein expression was induced by Nisin. Expression of GFP and Cell by the recombinant L. lactis was confirmed using SDS-PAGE, fluorescence detection, and Congo red assays. A feeding experiment showed that oral administration of pNZ8149-GFP-Cell/NZ3900 significantly increased the digestibility of dietary fiber in geese fed either a maize stalk diet or a rice chaff diet. Therefore, oral administration of recombinant L. lactis cells expressing the cellulase gene increases fiber digestibility in geese, offering a way to increase the utilization of dietary fiber in geese.

  20. Experimental determination of control of glycolysis in Lactococcus lactis

    DEFF Research Database (Denmark)

    Købmann, Brian Jensen; Andersen, Heidi Winterberg; Solem, Christian

    2002-01-01

    ), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), pyruvate kinase (PYK) and lactate dehydrogenase (LDH) are shown to have no significant control on the glycolytic flux in exponentially growing cells of L. lactis MG1363. Introduction of an uncoupled ATPase activity results in uncoupling of glycolysis from biomass...... production. With MG1363 growing in defined medium supplemented with glucose, the ATP demanding processes do not have a significant control on the glycolytic flux; it appears that glycolysis is running at maximal rate. It is likely that the flux control is distributed over many enzymes in L. lactis...

  1. Proteome analysis of the purine stimulon from Lactococcus lactis

    DEFF Research Database (Denmark)

    Beyer, N.H.; Roepstorff, P.; Hammer, Karin

    2003-01-01

    kinase) and translation elongation factors (GTPases: EF-TU, EF-G). Two Dcu proteins could not be identified. Out of 28 proteins subjected to mass spectrometry, 19 could be readily identified despite the fact that only the genome sequence of a strain of L. lactis subsp. lactis was available. The two...... subspecies share about 85% sequence identity, comparable to the genetic distance between Escherichia coli and Salmonella typhimurium. A success rate of 68% indicates that it may be feasible to perform proteomics based upon genomic sequences of relatives outside the genus....

  2. The prophylactic effect of probiotic Enterococcus lactis IW5 against different human cancer cells

    Directory of Open Access Journals (Sweden)

    YOUSEF eNAMI

    2015-11-01

    Full Text Available Enterococcus lactis IW5 was obtained from human gut and the potential probiotic characteristics of this organism were then evaluated. Results showed that this strain was highly resistant to low pH and high bile salt and adhered strongly to Caco-2 human epithelial colorectal cell lines. The supernatant of E. lactis IW5 strongly inhibited the growth of several pathogenic bacteria and decreased the viability of different cancer cells, such as HeLa, AGS, HT-29, and MCF-7. Conversely, E. lactis IW5 did not inhibit the viability of normal FHs-74 cells. This strain did not generate toxic enzymes, including β-glucosidase, β-glucuronidase, and N-acetyl-β-glucosaminidase and was highly susceptible to ampicillin, gentamycin, penicillin, vancomycin, clindamycin, sulfamethoxazol, and chloramphenicol but resistant to erythromycin and tetracyclin. This study provided evidence for the effect of E. lactis IW5 on cancer cells. Therefore, E. lactis IW5, as a bioactive therapeutics, should be subjected to other relevant tests to verify the therapeutic suitability of this strain for clinical applications.

  3. Cell wall anchoring of the Campylobacter antigens to Lactococcus lactis

    Directory of Open Access Journals (Sweden)

    Patrycja Anna Kobierecka

    2016-02-01

    Full Text Available Campylobacter jejuni is the most frequent cause of human food-borne gastroenteritis and chicken meat is the main source of infection. Recent studies showed that broiler chicken immunization against Campylobacter should be the most efficient way to lower the number of human infections by this pathogen. Induction of the mucosal immune system after oral antigen administration should provide protective immunity to chickens. In this work we tested the usefulness of Lactococcus lactis, the most extensively studied lactic acid bacterium, as a delivery vector for Campylobacter antigens. First we constructed hybrid protein – CjaA antigen presenting CjaD peptide epitopes on its surface. We showed that specific rabbit anti-rCjaAD serum reacted strongly with both CjaA and CjaD produced by a wild type Campylobacter jejuni strain. Next, rCjaAD and CjaA were fused to the C-terminus of the L. lactis YndF containing the LPTXG motif. The genes expressing these proteins were transcribed under control of the L. lactis Usp45 promoter and their products contain the Usp45 signal sequences. This strategy ensures a cell surface location of both analysed proteins, which was confirmed by immunofluorescence assay. In order to evaluate the impact of antigen location on vaccine prototype efficacy, a L. lactis strain producing cytoplasm-located rCjaAD was also generated. Animal experiments showed a decrease of Campylobacter cecal load in vaccinated birds as compared with the control group and showed that the L. lactis harboring the surface-exposed rCjaAD antigen afforded greater protection than the L. lactis producing cytoplasm-located rCjaAD. To the best of our knowledge, this is the first attempt to employ LAB (Lactic Acid Bacteria strains as a mucosal delivery vehicle for chicken immunization. Although the observed reduction of chicken colonization by Campylobacter resulting from vaccination was rather moderate, the experiments showed that LAB strains can be considered

  4. Lactose metabolism in Streptococcus lactis: studies with a mutant lacking glucokinase and mannose-phosphotransferase activities

    International Nuclear Information System (INIS)

    Thompson, J.; Chassy, B.M.; Egan, W.

    1985-01-01

    A mutant of Streptococcus lactis 133 has been isolated that lacks both glucokinase and phosphoenolpyruvate-dependent mannose- phosphotransferase (mannose-PTS) activities. The double mutant S. lactis 133 mannose-PTSd GK- is unable to utilize either exogenously supplied or intracellularly generated glucose for growth. Fluorographic analyses of metabolites formed during the metabolism of [ 14 C]lactose labeled specifically in the glucose or galactosyl moiety established that the cells were unable to phosphorylate intracellular glucose. However, cells of S. lactis 133 mannose-PTSd GK- readily metabolized intracellular glucose 6-phosphate, and the growth rates and cell yield of the mutant and parental strains on sucrose were the same. During growth on lactose, S. lactis 133 mannose-PTSd GK- fermented only the galactose moiety of the disaccharide, and 1 mol of glucose was generated per mol of lactose consumed. For an equivalent concentration of lactose, the cell yield of the mutant was 50% that of the wild type. The specific rate of lactose utilization by growing cells of S. lactis 133 mannose-PTSd GK- was ca. 50% greater than that of the wild type, but the cell doubling times were 70 and 47 min, respectively. High-resolution 31 P nuclear magnetic resonance studies of lactose transport by starved cells of S. lactis 133 and S. lactis 133 mannose-PTSd GK- showed that the latter cells contained elevated lactose-PTS activity. Throughout exponential growth on lactose, the mutant maintained an intracellular steady-state glucose concentration of 100 mM

  5. Lactose metabolism in Streptococcus lactis: studies with a mutant lacking glucokinase and mannose-phosphotransferase activities

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, J.; Chassy, B.M.; Egan, W.

    1985-04-01

    A mutant of Streptococcus lactis 133 has been isolated that lacks both glucokinase and phosphoenolpyruvate-dependent mannose- phosphotransferase (mannose-PTS) activities. The double mutant S. lactis 133 mannose-PTSd GK- is unable to utilize either exogenously supplied or intracellularly generated glucose for growth. Fluorographic analyses of metabolites formed during the metabolism of (/sup 14/C)lactose labeled specifically in the glucose or galactosyl moiety established that the cells were unable to phosphorylate intracellular glucose. However, cells of S. lactis 133 mannose-PTSd GK- readily metabolized intracellular glucose 6-phosphate, and the growth rates and cell yield of the mutant and parental strains on sucrose were the same. During growth on lactose, S. lactis 133 mannose-PTSd GK- fermented only the galactose moiety of the disaccharide, and 1 mol of glucose was generated per mol of lactose consumed. For an equivalent concentration of lactose, the cell yield of the mutant was 50% that of the wild type. The specific rate of lactose utilization by growing cells of S. lactis 133 mannose-PTSd GK- was ca. 50% greater than that of the wild type, but the cell doubling times were 70 and 47 min, respectively. High-resolution /sup 31/P nuclear magnetic resonance studies of lactose transport by starved cells of S. lactis 133 and S. lactis 133 mannose-PTSd GK- showed that the latter cells contained elevated lactose-PTS activity. Throughout exponential growth on lactose, the mutant maintained an intracellular steady-state glucose concentration of 100 mM.

  6. A counterselection method for Lactococcus lactis genome editing based on class IIa bacteriocin sensitivity.

    Science.gov (United States)

    Wan, Xing; Usvalampi, Anne M; Saris, Per E J; Takala, Timo M

    2016-11-01

    In this paper, we present a new counterselection method for deleting fragments from Lactococcus lactis chromosome. The method uses a non-replicating plasmid vector, which integrates into the chromosome and makes the cell sensitive to bacteriocins. The integration vector carries pUC ori functional in Escherichia coli but not in L. lactis, an erythromycin resistance gene for selecting single crossover integrants, and two fragments from L. lactis chromosome for homologous recombinations. In addition, the integration vector is equipped with the Listeria monocytogenes gene mptC encoding the mannose-phosphotransferase system component IIC, the receptor for class IIa bacteriocins. Expression of mptC from the integration vector renders the naturally resistant L. lactis sensitive to class IIa bacteriocins. This sensitivity is then used to select the double crossover colonies on bacteriocin agar. Only the cells which have regained the endogenous bacteriocin resistance through the loss of the mptC plasmid will survive. The colonies carrying the desired deletion can then be distinguished from the wild-type revertants by PCR. By using the class IIa bacteriocins leucocin A, leucocin C or pediocin AcH as the counterselective agents, we deleted 22- and 33-kb chromosomal fragments from the wild-type nisin producing L. lactis strain N8. In conclusion, this counterselection method presented here is a convenient, efficient and inexpensive technique to generate successive deletions in L. lactis chromosome.

  7. Immune effects of the probiotic Bifidobacterium breve

    NARCIS (Netherlands)

    Ezendam J; Loveren H van; TOX

    2007-01-01

    Bifidobacterium breve, a probiotic, has beneficial effects on both allergy and autoimmunity - an immune reaction against the body's own constituents -in experimental animals. Probiotics are called 'friendly bacteria' in advertisements, in which manufacturers claim their beneficial effects on gut

  8. Hemin reconstitutes proton extrusion in an H+-ATPase-negative mutant of Lactococcus lactis

    DEFF Research Database (Denmark)

    Blank, L.M.; Købmann, Brian Jensen; Michelsen, Ole

    2001-01-01

    H+-ATPase is considered essential for growth of Lactococcus lactis. However, media containing hemin restored the aerobic growth of an H+-ATPase-negative mutant, suggesting that hemin complements proton extrusion. We show that inverted membrane vesicles prepared from hemin-grown L. lactis cells...

  9. Elucidating Flux Regulation of the Fermentation Modes of Lactococcus lactis

    DEFF Research Database (Denmark)

    Chan, Siu Hung Joshua

    an important subject for basic research in cellular metabolism because L. lactis exhibits an interesting metabolic shift. Under anaerobic conditions, on fast fermentable sugars, L. lactis produces lactate as the primary product, known as homolactic fermentation but on slowly fermentable sugars, significant...... amounts of formate, acetate and ethanol are formed, known as mixed-acid fermentation. This shift is termed the mixedacid shift. This type of shift between a low-yield and a high-yield metabolism has drawn a lot of research focus and has similarly been observed in other bacteria, yeast and even tumor cells....... Efforts have been put to find out the mechanism regulating the mixed-acid shift as well as to answer questions such as why L. lactis prefers such a switch. Until now, some pieces of evidence have been reported and several factors and models have been proposed as the keys to regulating the shift, including...

  10. Promotion of intestinal peristalsis by Bifidobacterium spp. capable of hydrolysing sennosides in mice.

    Directory of Open Access Journals (Sweden)

    Mitsuharu Matsumoto

    Full Text Available BACKGROUND: While there are a variety of identifiable causes of constipation, even idiopathic constipation has different possible mechanisms. Sennosides, the main laxative constituents of Daio, an ancient Kampo medicine, are prodrugs that are converted to an active principle, rheinanthrone, by intestinal microbiota. In this study, we aimed to determine the sennoside hydrolysis ability of lactic acid bacterial strains and bifidobacteria in the intestine and to investigate their effect on intestinal peristalsis in mice. METHODOLOGY/PRINCIPAL FINDINGS: A total of 88 lactic acid bacterial strains and 47 bifidobacterial strains were evaluated for their ability to hydrolyze sennosides. Our results revealed that 4 strains, all belonging to the genus Bifidobacterium, had strong sennoside hydrolysis ability, exhibiting a decrease of >70% of sennoside content. By thin-layer chromatography analysis, rheinanthrone was detected in the medium cultured with B. pseudocatenulatum LKM10070 and B. animalis subsp. lactis LKM512. The fecal sennoside contents significantly (P<0.001 decreased upon oral administration of these strains as compared with the control. Intestinal peristalsis activity was measured by the moved distance of the charcoal powder administered orally. The distance travelled by the charcoal powder in LKM512-treated mice was significantly longer than that of control (P<0.05. Intestinal microbiota were analysed by real-time PCR and terminal-restriction fragment length polymorphism. The diversity of the intestinal microbiota was reduced by kanamycin treatment and the diversity was not recovered by LKM512 treatment. CONCLUSION/SIGNIFICANCE: We demonstrated that intestinal peristalsis was promoted by rheinanthrone produced by hydrolysis of sennoside by strain LKM512 and LKM10070.

  11. Production of Recombinant Peanut Allergen Ara h 2 using Lactococcus lactis

    Directory of Open Access Journals (Sweden)

    Frøkiær Hanne

    2007-08-01

    Full Text Available Abstract Background Natural allergen sources can supply large quantities of authentic allergen mixtures for use as immunotherapeutics. However, such extracts are complex, difficult to define, vary from batch to batch, which may lead to unpredictable efficacy and/or unacceptable levels of side effects. The use of recombinant expression systems for allergen production can alleviate some of these issues. Several allergens have been tested in high-level expression systems and in most cases show immunereactivity comparable to their natural counterparts. The gram positive lactic acid bacterium Lactococcus lactis is an attractive microorganism for use in the production of protein therapeutics. L. lactis is considered food grade, free of endotoxins, and is able to secrete the heterologous product together with few other native proteins. Hypersensitivity to peanut represents a serious allergic problem. Some of the major allergens in peanut have been described. However, for therapeutic usage more information about the individual allergenic components is needed. In this paper we report recombinant production of the Ara h 2 peanut allergen using L. lactis. Results A synthetic ara h 2 gene was cloned into an L. lactis expression plasmid containing the P170 promoter and the SP310mut2 signal sequence. Flask cultures grown overnight showed secretion of the 17 kDa Ara h 2 protein. A batch fermentation resulted in 40 mg/L recombinant Ara h 2. Purification of Ara h 2 from the culture supernatant was done by hydrophobic exclusion and size separation. Mass spectrometry and N-terminal analysis showed a recombinant Ara h 2 of full length and correctly processed by the signal peptidase. The immunological activity of recombinant Ara h 2 was analysed by ELISA using antibodies specific for native Ara h 2. The recombinant Ara h 2 showed comparable immunereactivity to that of native Ara h 2. Conclusion Recombinant production of Ara h 2 using L. lactis can offer high yields

  12. Expanding the molecular toolbox for Lactococcus lactis: construction of an inducible thioredoxin gene fusion expression system

    LENUS (Irish Health Repository)

    Douillard, Francois P

    2011-08-09

    Abstract Background The development of the Nisin Inducible Controlled Expression (NICE) system in the food-grade bacterium Lactococcus lactis subsp. cremoris represents a cornerstone in the use of Gram-positive bacterial expression systems for biotechnological purposes. However, proteins that are subjected to such over-expression in L. lactis may suffer from improper folding, inclusion body formation and\\/or protein degradation, thereby significantly reducing the yield of soluble target protein. Although such drawbacks are not specific to L. lactis, no molecular tools have been developed to prevent or circumvent these recurrent problems of protein expression in L. lactis. Results Mimicking thioredoxin gene fusion systems available for E. coli, two nisin-inducible expression vectors were constructed to over-produce various proteins in L. lactis as thioredoxin fusion proteins. In this study, we demonstrate that our novel L. lactis fusion partner expression vectors allow high-level expression of soluble heterologous proteins Tuc2009 ORF40, Bbr_0140 and Tuc2009 BppU\\/BppL that were previously insoluble or not expressed using existing L. lactis expression vectors. Over-expressed proteins were subsequently purified by Ni-TED affinity chromatography. Intact heterologous proteins were detected by immunoblotting analyses. We also show that the thioredoxin moiety of the purified fusion protein was specifically and efficiently cleaved off by enterokinase treatment. Conclusions This study is the first description of a thioredoxin gene fusion expression system, purposely developed to circumvent problems associated with protein over-expression in L. lactis. It was shown to prevent protein insolubility and degradation, allowing sufficient production of soluble proteins for further structural and functional characterization.

  13. Environmental stress responses in Lactococcus lactis

    NARCIS (Netherlands)

    Sanders, JW; Venema, G; Kok, J

    Bacteria can encounter a variety of physical conditions during their life, Bacterial cells are able to survive these (often adverse) conditions by the induction of specific or general protection mechanisms. The lactic acid bacterium Lactococcus lactis is widely used for the production of cheese.

  14. Controlles modulation of folate polyglutamyl tail length by metabolic engineering of Lactococcus lactis

    NARCIS (Netherlands)

    Sybesma, W.F.H.; Born, van den E.; Starrenburg, M.; Mierau, I.; Kleerebezem, M.; Vos, de W.M.; Hugenholtz, J.

    2003-01-01

    The dairy starter bacterium Lactococcus lactis is able to synthesize folate and accumulates >90% of the produced folate intracellularly, predominantly in the polyglutamyl form. Approximately 10% of the produced folate is released into the environment. Overexpression of folC in L. lactis led to an

  15. Effect of sublethal preculturing on the survival of probiotics and metabolite formation in set-yoghurt

    NARCIS (Netherlands)

    Settachaimongkon, S.; Valenberg, van H.J.F.; Winata, V.; Wang, X.; Nout, M.J.R.; Hooijdonk, van A.C.M.; Zwietering, M.H.; Smid, E.J.

    2015-01-01

    The objective of this study was to investigate the effect of preculturing of Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp. lactis BB12 under sublethal stress conditions on their survival and metabolite formation in set-yoghurt. Prior to co-cultivation with yoghurt starters in milk,

  16. Isolation of a human intestinal anaerobe, Bifidobacterium sp. strain SEN, capable of hydrolyzing sennosides to sennidins.

    OpenAIRE

    Akao, T; Che, Q M; Kobashi, K; Yang, L; Hattori, M; Namba, T

    1994-01-01

    A strictly anaerobic bacterium capable of metabolizing sennosides was isolated from human feces and identified as Bifidobacterium sp., named strain SEN. The bacterium hydrolyzed sennosides A and B to sennidins A and B via sennidin A and B 8-monoglucosides, respectively. Among nine species of Bifidobacterium having beta-glucosidase activity, only Bifidobacterium dentium and B. adolescentis metabolized sennoside B to sennidin B, suggesting that the sennoside-metabolizing bacteria produce a nove...

  17. Quantitative assessment of Lactococcus lactis subsp. cremoris present in artisanal raw cow’s milk cheese

    Directory of Open Access Journals (Sweden)

    Milena Alicja Stachelska

    2018-01-01

    Full Text Available Lactococcus lactis subsp. cremoris belongs to lactic acid bacteria that play a crucial role in cheese production and it is known to be beneficial to human health. The aim of the study was to establish a rapid and accurate quantitative real-time polymerase chain reaction (qPCR method to detect and enumerate L. lactis subsp. cremoris in artisanal raw cow’s milk cheese. Artisanal raw cow’s milk cheese samples were used to check for presence and number of L. lactis subsp. cremoris strains. The method applies a set of target-specific PCR (polymerase chain reaction primers and a fluorogenic probe, and amplifies a part of the LACR_RS01280 gene that encodes the aminoacetone oxidase family flavin adenine dinucleotide (FAD binding enzyme. All 5 L. lactis subsp. cremoris strains examined were found to be qPCR positive. There was no signal recorded for 8 strains which belong to closely related species. The limit of detection amounted to ten copies per reaction and the assay indicated a linear dynamic range of seven logs. This method may be applied in detection and enumeration of L. lactis subsp. cremoris in cheese during its ripening. Moreover, it may be applied to examine the distribution of L. lactis subsp. cremoris during the cheese production and ripening.

  18. Enhancement of growth performance and hematological changes in rainbow trout (Onchorhynchus mykiss alevins fed with Bifidobacterium bacteria

    Directory of Open Access Journals (Sweden)

    Javad Sahandi

    2017-04-01

    Full Text Available The study of probiotic application as an important rearing strategy was started more than 30 years ago and most of these studies were carried out to increase growth and survival of larvae. Effect of Bifidobacterium animalis PTTC-1631 and B. lactis PTTC-1736 as probiotic supplement has been studied on growth performance and hematological changes on rainbow trout, Oncorhynchus mykiss alevins with initial body weight of 0.583 ± 0.197 g. The commercial diet was supplemented with graded levels of probiotics (1×107, 2×107 and 3×107 CFU g-1 dry feed to obtain 3 sets of experimental diets (T1, T2, andT3 respectively and fed four times a day for 60 days. T1 alevin showed the best growth performance in terms of specific growth rate, weight gain, metabolic growth rate, feed conversion ratio and survival rate. The highest red and white blood cell concentrations were noticed in fish fed T2 and T3 diets, respectively, no significant difference was observed in hemoglobin content. T1 showed the significant elevation of serum biochemical parameters and reduction of cortisol level. The results of present study might suggest likely positive effects of probiotic supplements with concentration of 1×107 CFU g-1 dry feed on growth and hematology on rainbow trout alevins.

  19. Immune response to Bifidobacterium bifidum strains support Treg/Th17 plasticity.

    Directory of Open Access Journals (Sweden)

    Patricia López

    Full Text Available In this work we analyzed the immune activation properties of different Bifidobacterium strains in order to establish their ability as inductors of specific effector (Th or regulatory (Treg responses. First, we determined the cytokine pattern induced by 21 Bifidobacterium strains in peripheral blood mononuclear cells (PBMCs. Results showed that four Bifidobacterium bifidum strains showed the highest production of IL-17 as well as a poor secretion of IFNγ and TNFα, suggesting a Th17 profile whereas other Bifidobacterium strains exhibited a Th1-suggestive profile. Given the key role of Th17 subsets in mucosal defence, strains suggestive of Th17 responses and the putative Th1 Bifidobacterium breve BM12/11 were selected to stimulate dendritic cells (DC to further determine their capability to induce the differentiation of naïve CD4(+ lymphocytes toward different Th or Treg cells. All selected strains were able to induce phenotypic DC maturation, but showed differences in cytokine stimulation, DC treated with the putative Th17 strains displaying high IL-1β/IL-12 and low IL-12/IL-10 index, whereas BM12/11-DC exhibited the highest IL-12/IL-10 ratio. Differentiation of naïve lymphocytes confirmed Th1 polarization by BM12/11. Unexpectedly, any B. bifidum strain showed significant capability for Th17 generation, and they were able to generate functional Treg, thus suggesting differences between in vivo and vitro responses. In fact, activation of memory lymphocytes present in PBMCS with these bacteria, point out the presence in vivo of specific Th17 cells, supporting the plasticity of Treg/Th17 populations and the key role of commensal bacteria in mucosal tolerance and T cell reprogramming when needed.

  20. The proteolytic system of Lactococcus lactis

    NARCIS (Netherlands)

    Kunji, Edmundus Richardus Stephanus

    1997-01-01

    The bacterium Lactococcus lactis usues an extencive proteolytic system to utilize milk proteins (caseins) in orde to meet its need for amino acids. The genetic and biochemical properties of the putative components of the proteolytic pathway are well-described. However, little is known about the role

  1. Heterologous Expression of Aldehyde Dehydrogenase in Lactococcus lactis for Acetaldehyde Detoxification at Low pH.

    Science.gov (United States)

    Lyu, Yunbin; LaPointe, Gisèle; Zhong, Lei; Lu, Jing; Zhang, Chong; Lu, Zhaoxin

    2018-02-01

    Aldehyde dehydrogenase (E.C. 1.2.1.x) can catalyze detoxification of acetaldehydes. A novel acetaldehyde dehydrogenase (istALDH) from the non-Saccharomyces yeast Issatchenkia terricola strain XJ-2 has been previously characterized. In this work, Lactococcus lactis with the NIsin Controlled Expression (NICE) System was applied to express the aldehyde dehydrogenase gene (istALDH) in order to catalyze oxidation of acetaldehyde at low pH. A recombinant L. lactis NZ3900 was obtained and applied for the detoxification of acetaldehyde as whole-cell biocatalysts. The activity of IstALDH in L. lactis NZ3900 (pNZ8148-istALDH) reached 36.4 U mL -1 when the recombinant cells were induced with 50 ng mL -1 nisin at 20 °C for 2 h. The IstALDH activity of recombinant L. lactis cells showed higher stability at 37 °C and pH 4.0 compared with the crude enzyme. L. lactis NZ3900 (pNZ8148-istALDH) could convert acetaldehyde at pH 2.0 while the crude enzyme could not. Moreover, the resting cells of L. lactis NZ3900 (pNZ8148-istALDH) showed a 2.5-fold higher activity and better stability in catalyzing oxidation of acetaldehyde at pH 2.0 compared with that of Escherichia coli expressing the IstALDH. Taken together, the L. lactis cells expressing recombinant IstALDH are potential whole-cell biocatalysts that can be applied in the detoxification of aldehydes.

  2. Antagonistic activities of some Bifidobacterium sp. strains isolated from resident infant gastrointestinal microbiota on Gram-negative enteric pathogens.

    Science.gov (United States)

    Delcaru, Cristina; Alexandru, Ionela; Podgoreanu, Paulina; Cristea, Violeta Corina; Bleotu, Coralia; Chifiriuc, Mariana Carmen; Bezirtzoglou, Eugenia; Lazar, Veronica

    2016-06-01

    The gastrointestinal microbiota contributes to the consolidation of the anti-infectious barrier against enteric pathogens. The purpose of this study was to investigate the influence of Bifidobacterium sp. strains, recently isolated from infant gastrointestinal microbiota on the in vitro growth and virulence features expression of enteropathogenic bacterial strains. The antibacterial activity of twelve Bifidobacterium sp. strains isolated from human feces was examined in vitro against a wide range of Gram negative pathogenic strains isolated from 30 infant patients (3 days to 5 years old) with diarrhea. Both potential probiotic strains (Bifidobacterium longum, Bifidobacterium pseudocatenulatum, Bifidobacterium catenulatum, Bifidobacterium breve, Bifidobacterium ruminantium) and enteropathogenic strains (EPEC, EIEC, Klebsiella pneumoniae, Salmonella sp., Yersinia enterocolitica, Pseudomonas aeruginosa) were identified by MALDI-TOF and confirmed serologically when needed. The bactericidal activity, growth curve, adherence to the cellular HEp-2 substratum and production of soluble virulence factors have been assessed in the presence of different Bifidobacterium sp. cultures and fractions (whole culture and free-cell supernatants). Among the twelve Bifidobacterium sp. strains, the largest spectrum of antimicrobial activity against 9 of the 18 enteropathogenic strains was revealed for a B. breve strain recently isolated from infant intestinal feces. The whole culture and free-cell supernatant of B. breve culture decreased the multiplication rate, shortened the log phase and the total duration of the growth curve, with an earlier entrance in the decline phase and inhibited the adherence capacity to a cellular substratum and the swimming/swarming motility too. These results indicate the significant probiotic potential of the B. breve strain. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Leaching of DOC, DN, and inorganic constituents from scrap tires.

    Science.gov (United States)

    Selbes, Meric; Yilmaz, Ozge; Khan, Abdul A; Karanfil, Tanju

    2015-11-01

    One concern for recycle and reuse of scrap tires is the leaching of tire constituents (organic and inorganic) with time, and their subsequent potential harmful impacts in environment. The main objective of this study was to examine the leaching of dissolved organic carbon (DOC), dissolved nitrogen (DN), and selected inorganic constituents from scrap tires. Different sizes of tire chips and crumb rubber were exposed to leaching solutions with pH's ranging from 3.0 to 10.0 for 28days. The leaching of DOC and DN were found to be higher for smaller size tire chips; however, the leaching of inorganic constituents was independent of the size. In general, basic pH conditions increased the leaching of DOC and DN, whereas acidic pH conditions led to elevated concentrations of metals. Leaching was minimal around the neutral pH values for all the monitored parameters. Analysis of the leaching rates showed that components associated with the rubbery portion of the tires (DOC, DN, zinc, calcium, magnesium, etc.) exhibited an initial rapid followed by a slow release. On the other hand, a constant rate of leaching was observed for iron and manganese, which are attributed to the metal wires present inside the tires. Although the total amounts that leached varied, the observed leaching rates were similar for all tire chip sizes and leaching solutions. Operation under neutral pH conditions, use of larger size tire chips, prewashing of tires, and removal of metal wires prior to application will reduce the impact of tire recycle and reuse. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. CTP limitation increases expression of CTP synthase in Lactococcus lactis

    DEFF Research Database (Denmark)

    Jørgensen, C.M.; Hammer, Karin; Martinussen, Jan

    2003-01-01

    CTP synthase is encoded by the pyrG gene and catalyzes the conversion of UTP to CTP. A Lactococcus lactis pyrG mutant with a cytidine requirement was constructed, in which beta-galactosidase activity in a pyrG-lacLM transcriptional fusion was used to monitor gene expression of pyrG. A 10-fold...... decrease in the CTP pool induced by cytidine limitation was found to immediately increase expression of the L. lactis pyrG gene. The final level of expression of pyrG is 37-fold higher than the uninduced level. CTP limitation has pronounced effects on central cellular metabolism, and both RNA and protein...... for regulation of the pyrG gene. It is possible to fold the pyrG leader in an alternative structure that would prevent the formation of the terminator. We suggest a model for pyrG regulation in L. lactis, and probably in other gram-positive bacteria as well, in which pyrG expression is directly dependent...

  5. Strains of Lactococcus lactis with a partial pyrimidine requirement show sensitivity toward aspartic acid

    DEFF Research Database (Denmark)

    Wadskov-Hansen, Steen Lyders Lerche; Martinussen, Jan

    2009-01-01

    The growth rate of the widely used laboratory strain Lactococcus lactis subsp. cremoris LM0230 was reduced if aspartic acid were present in the growth medium. The strain LM0230 is a plasmid- and phage-cured derivative of L. lactis subsp. cremoris C2, the ancestor of the original dairy isolate L...... with the wild-type strain, and this varied with the concentration of aspartic acid. The observed effect of aspartate could be explained by the accumulation of the toxic pyrimidine de novo pathway intermediate, carbamoyl aspartate. Assays of the pyrimidine biosynthetic enzymes of L. lactis LM0230 showed...... that the partial pyrimidine requirement can be explained by a low specific activity of the pyrimidine biosynthetic enzymes. In conclusion, L. lactis LM0230 during the process of plasmid- and prophage-curing has acquired a partial pyrimidine requirement resulting in sensitivity toward aspartic acid....

  6. Development of Chemically Defined Media to Express Trp-Analog-Labeled Proteins in a Lactococcus lactis Trp Auxotroph.

    Science.gov (United States)

    Shao, Jinfeng; Marcondes, Marcelo F M; Oliveira, Vitor; Broos, Jaap

    2016-01-01

    Chemically defined media for growth of Lactococcus lactis strains contain about 50 components, making them laborious and expensive growth media. However, they are crucial for metabolism studies as well as for expression of heterologous proteins labeled with unnatural amino acids. In particular, the L. lactis Trp auxotroph PA1002, overexpressing the tryptophanyl tRNA synthetase enzyme of L. lactis, is very suitable for the biosynthetic incorporation of Trp analogs in proteins because of its most relaxed substrate specificity reported towards Trp analogs. Here we present two much simpler defined media for L. lactis, which consist of only 24 or 31 components, respectively, and with which the L. lactis Trp auxotroph shows similar growth characteristics as with a 50-component chemically defined medium. Importantly, the expression levels of two recombinant proteins used for evaluation were up to 2-3 times higher in these new media than in the 50-component medium, without affecting the Trp analog incorporation efficiency. Taken together, the simplest chemically defined media reported so far for L. lactis are presented. Since L. lactis also shows auxotrophy for Arg, His, Ile, Leu Val, and Met, our simplified media may also be useful for the biosynthetic incorporation of analogs of these five amino acids. © 2016 The Author(s) Published by S. Karger AG, Basel.

  7. Is Bifidobacterium breve effective in the treatment of childhood constipation? Results from a pilot study

    NARCIS (Netherlands)

    Tabbers, M. M.; de Milliano, I.; Roseboom, M. G.; Benninga, M. A.

    2011-01-01

    Probiotics are increasingly used in the treatment of functional gastrointestinal disorders. Studies in constipated adults with a Bifidus yoghurt (containing Bifidobacterium breve, Bifidobacterium bifidum and Lactobacillus acidophilus) showed a significant increase in defecation frequency. The aim of

  8. Heterologous Protein Expression by Lactococcus lactis

    NARCIS (Netherlands)

    Villatoro-Hernández, J.; Kuipers, O.P.; Saucedo-Cárdenas, O.; Montes-de-Oca-Luna, R.

    2012-01-01

    This chapter describes the use of Lactococcus lactis as a safe and efficient cell factory to produce heterologous proteins of medical interest. The relevance of the use of this lactic acid bacterium (LAB) is that it is a noncolonizing, nonpathogenic microorganism that can be delivered in vivo at a

  9. The extracellular proteinase of Lactococcus lactis

    NARCIS (Netherlands)

    Laan, Harm Willem Frederik

    1991-01-01

    Lactococci are used in the production of fermentated dairy products of which cheese is one of the most important. In starter cultures used in dutch cheese manufacturing Lactococcus lactis the dominants pecies. The main functions of the Lactococci are a fast conversion of lactose into lactate and the

  10. Comparative genomics of the Bifidobacterium breve taxon

    NARCIS (Netherlands)

    Bottacini, Francesca; O'Connell Motherway, Mary; Kuczynski, Justin; O'Connell, Kerry Joan; Serafini, Fausta; Duranti, Sabrina; Milani, Christian; Turroni, Francesca; Lugli, Gabriele Andrea; Zomer, Aldert|info:eu-repo/dai/nl/304642754; Zhurina, Daria; Riedel, Christian; Ventura, Marco; van Sinderen, Douwe

    2014-01-01

    BACKGROUND: Bifidobacteria are commonly found as part of the microbiota of the gastrointestinal tract (GIT) of a broad range of hosts, where their presence is positively correlated with the host's health status. In this study, we assessed the genomes of thirteen representatives of Bifidobacterium

  11. Inside the adaptation process of Lactobacillus delbrueckii subsp. lactis to bile

    OpenAIRE

    Burns, Patricia; Sánchez García, Borja; Vinderola, Gabriel; Ruas-Madiedo, Patricia; Ruíz García, Lorena; Margolles Barros, Abelardo; Reinheimer, Jorge A.; González de los Reyes-Gavilán, Clara

    2010-01-01

    Progressive adaptation to bile might render some lactobacilli able to withstand physiological bile salt concentrations. In this work, the adaptation to bile was evaluated on previously isolated dairy strains of Lactobacillus delbrueckii subsp. lactis 200 and L. delbrueckii subsp. lactis 200+, a strain derived thereof with stable bile-resistant phenotype. The adaptation to bile was obtained by comparing cytosolic proteomes of both strains grown in the presence or absence of bile. Proteomics we...

  12. Expression of PprI from Deinococcus radiodurans Improves Lactic Acid Production and Stress Tolerance in Lactococcus lactis.

    Directory of Open Access Journals (Sweden)

    Xiangrong Dong

    Full Text Available PprI is a general switch protein that regulates the expression of certain proteins involved in pathways of cellular resistance in the extremophilic bacterium Deinococcus radiodurans. In this study, we transformed pprI into Lactococcus lactis strain MG1363 using the lactococcal shuttle vector pMG36e and investigated its effects on the tolerance and lactic acid production of L. lactis while under stress. PprI was stably expressed in L. lactis as confirmed by western blot assays. L. lactis expressing PprI exhibited significantly improved resistance to oxidative stress and high osmotic pressure. This enhanced cellular tolerance to stressors might be due to the regulation of resistance-related genes (e.g., recA, recO, sodA, and nah by pprI. Moreover, transformed L. lactis demonstrated increased lactic acid production, attributed to enhanced lactate dehydrogenase activity. These results suggest that pprI can improve the tolerance of L. lactis to environmental stresses, and this transformed bacterial strain is a promising candidate for industrial applications of lactic acid production.

  13. Expression of PprI from Deinococcus radiodurans Improves Lactic Acid Production and Stress Tolerance in Lactococcus lactis.

    Science.gov (United States)

    Dong, Xiangrong; Tian, Bing; Dai, Shang; Li, Tao; Guo, Linna; Tan, Zhongfang; Jiao, Zhen; Jin, Qingsheng; Wang, Yanping; Hua, Yuejin

    2015-01-01

    PprI is a general switch protein that regulates the expression of certain proteins involved in pathways of cellular resistance in the extremophilic bacterium Deinococcus radiodurans. In this study, we transformed pprI into Lactococcus lactis strain MG1363 using the lactococcal shuttle vector pMG36e and investigated its effects on the tolerance and lactic acid production of L. lactis while under stress. PprI was stably expressed in L. lactis as confirmed by western blot assays. L. lactis expressing PprI exhibited significantly improved resistance to oxidative stress and high osmotic pressure. This enhanced cellular tolerance to stressors might be due to the regulation of resistance-related genes (e.g., recA, recO, sodA, and nah) by pprI. Moreover, transformed L. lactis demonstrated increased lactic acid production, attributed to enhanced lactate dehydrogenase activity. These results suggest that pprI can improve the tolerance of L. lactis to environmental stresses, and this transformed bacterial strain is a promising candidate for industrial applications of lactic acid production.

  14. Evaluation of Lactococcus lactis Isolates from Nondairy Sources with Potential Dairy Applications Reveals Extensive Phenotype-Genotype Disparity and Implications for a Revised Species.

    Science.gov (United States)

    Cavanagh, Daniel; Casey, Aidan; Altermann, Eric; Cotter, Paul D; Fitzgerald, Gerald F; McAuliffe, Olivia

    2015-06-15

    Lactococcus lactis is predominantly associated with dairy fermentations, but evidence suggests that the domesticated organism originated from a plant niche. L. lactis possesses an unusual taxonomic structure whereby strain phenotypes and genotypes often do not correlate, which in turn has led to confusion in L. lactis classification. A bank of L. lactis strains was isolated from various nondairy niches (grass, vegetables, and bovine rumen) and was further characterized on the basis of key technological traits, including growth in milk and key enzyme activities. Phenotypic analysis revealed all strains from nondairy sources to possess an L. lactis subsp. lactis phenotype (lactis phenotype); however, seven of these strains possessed an L. lactis subsp. cremoris genotype (cremoris genotype), determined by two separate PCR assays. Multilocus sequence typing (MLST) showed that strains with lactis and cremoris genotypes clustered together regardless of habitat, but it highlighted the increased diversity that exists among "wild" strains. Calculation of average nucleotide identity (ANI) and tetranucleotide frequency correlation coefficients (TETRA), using the JSpecies software tool, revealed that L. lactis subsp. cremoris and L. lactis subsp. lactis differ in ANI values by ∼14%, below the threshold set for species circumscription. Further analysis of strain TIFN3 and strains from nonindustrial backgrounds revealed TETRA values of lactis taxonomy. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  15. Sequencing and Transcriptional Analysis of the Biosynthesis Gene Cluster of Putrescine-Producing Lactococcus lactis ▿ †

    Science.gov (United States)

    Ladero, Victor; Rattray, Fergal P.; Mayo, Baltasar; Martín, María Cruz; Fernández, María; Alvarez, Miguel A.

    2011-01-01

    Lactococcus lactis is a prokaryotic microorganism with great importance as a culture starter and has become the model species among the lactic acid bacteria. The long and safe history of use of L. lactis in dairy fermentations has resulted in the classification of this species as GRAS (General Regarded As Safe) or QPS (Qualified Presumption of Safety). However, our group has identified several strains of L. lactis subsp. lactis and L. lactis subsp. cremoris that are able to produce putrescine from agmatine via the agmatine deiminase (AGDI) pathway. Putrescine is a biogenic amine that confers undesirable flavor characteristics and may even have toxic effects. The AGDI cluster of L. lactis is composed of a putative regulatory gene, aguR, followed by the genes (aguB, aguD, aguA, and aguC) encoding the catabolic enzymes. These genes are transcribed as an operon that is induced in the presence of agmatine. In some strains, an insertion (IS) element interrupts the transcription of the cluster, which results in a non-putrescine-producing phenotype. Based on this knowledge, a PCR-based test was developed in order to differentiate nonproducing L. lactis strains from those with a functional AGDI cluster. The analysis of the AGDI cluster and their flanking regions revealed that the capacity to produce putrescine via the AGDI pathway could be a specific characteristic that was lost during the adaptation to the milk environment by a process of reductive genome evolution. PMID:21803900

  16. Light Sensitivity of Lactococcus lactis Thioredoxin Reductase

    DEFF Research Database (Denmark)

    Skjoldager, Nicklas

    The thioredoxin system has evolved in all kingdoms of life acting as a key antioxidant system in the defense against oxidative stress. The thioredoxin system utilizes reducing equivalents from NADPH to reduce protein disulfide targets. The reducing equivalents are shuttled via a flavin and redox...... active dithiol motif in thioredoxin reductase (TrxR) to reduce the small ubiquitous thioredoxin (Trx). Trx in turn regulates the protein dithiol/disulfide balance by reduction of protein disulfide targets in e.g. ribonucleotide reductase, peroxiredoxins and methionine sulfoxide reductase. The glutathione......, thus expected to rely mainly on the Trx system for thiol-disulfide control. L. lactis is an important industrial microorganism used as starter culture in the dairy production of cheese, buttermilk etc. and known to be sensitive to oxidative stress. The L. lactis TrxR (LlTrxR) is a homodimeric...

  17. Impact of enzymatic hydrolyzed lactose on fermentation and growth of probiotic bacteria in whey

    Directory of Open Access Journals (Sweden)

    Katarina Lisak

    2011-06-01

    Full Text Available Taking in consideration the long time for whey fermentation using probiotic bacteria, the aim of this research was to determine if prior enzymatic hydrolysis of lactose influences microbial activities of Lactobacillus acidophilus La-5 or Bifidobacterium animalis subsp. lactis BB-12 in reconstituted sweet whey. During fermentation (at 37 °C, pH-value and viable cell counts were monitored. The fermented samples were sensory profiled. Lactose hydrolysis shortened the fermentation time of Lactobacillus acidophilus La-5 by 2 h, and viable cell count at the end of fermentation time was greater in hydrolyzed whey sample (~9.45 log10 CFU/mL when compared with the control sample (~8.91 log10 CFU/mL. In contrast, lactose hydrolysis in whey did not enhance the activity of Bifidobacterium animalis subsp. lactis BB-12. Lactose hydrolysis had slightly influence on sensory score of fermented samples, probably due to sweetness that masked the acidic taste of the product.

  18. The GH5 1,4-β-mannanase from Bifidobacterium animalis subsp. lactis Bl-04 possesses a low-affinity mannan-binding module and highlights the diversity of mannanolytic enzymes

    DEFF Research Database (Denmark)

    Morrill, Johan; Kulcinskaja, Evelina; Sulewska, Anna Maria

    2015-01-01

    β-Mannans are abundant and diverse plant structural and storage polysaccharides. Certain human gut microbiota members including health-promoting Bifidobacterium spp. catabolize dietary mannans. Little insight is available on the enzymology of mannan deconstruction in the gut ecological niche. Here....... Surface plasmon resonance analysis confirmed the binding of the CBM10 to manno-oligosaccharides, albeit with slightly lower affinity than the catalytic module of the enzyme. This is the first example of a low-affinity mannan-specific CBM, which forms a subfamily of CBM10 together with close homologs...

  19. Construction of a new shuttle vector for DNA delivery into mammalian cells using non-invasive Lactococcus lactis.

    Science.gov (United States)

    Yagnik, Bhrugu; Padh, Harish; Desai, Priti

    2016-04-01

    Use of food grade Lactococcus lactis (L. lactis) is fast emerging as a safe alternative for delivery of DNA vaccine. To attain efficient DNA delivery, L. lactis, a non-invasive bacterium is converted to invasive strain either by expressing proteins like Internalin A (InlA) or Fibronectin binding protein A (FnBPA) or through chemical treatments. However the safety status of invasive L. lactis is questionable. In the present report, we have shown that non-invasive L. lactis efficiently delivered the newly constructed reporter plasmid pPERDBY to mammalian cells without any chemical enhancers. The salient features of the vector are; I) Ability to replicate in two different hosts; Escherichia coli (E. coli) and Lactic Acid Bacteria (LAB), II) One of the smallest reporter plasmid for DNA vaccine, III) Enhanced Green Fluorescence Protein (EGFP) linked to Multiple Cloning Site (MCS), IV) Immunostimulatory CpG motifs functioning as an adjuvant. Expression of EGFP in pPERDBY transfected CHO-K1 and Caco-2 cells demonstrates its functionality. Non-invasive r-L. lactis was found efficient in delivering pPERDBY to Caco-2 cells. The in vitro data presented in this article supports the hypothesis that in the absence of invasive proteins or relevant chemical treatment, L. lactis was found efficient in delivering DNA to mammalian cells. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  20. Isolation of a human intestinal anaerobe, Bifidobacterium sp. strain SEN, capable of hydrolyzing sennosides to sennidins.

    Science.gov (United States)

    Akao, T; Che, Q M; Kobashi, K; Yang, L; Hattori, M; Namba, T

    1994-01-01

    A strictly anaerobic bacterium capable of metabolizing sennosides was isolated from human feces and identified as Bifidobacterium sp., named strain SEN. The bacterium hydrolyzed sennosides A and B to sennidins A and B via sennidin A and B 8-monoglucosides, respectively. Among nine species of Bifidobacterium having beta-glucosidase activity, only Bifidobacterium dentium and B. adolescentis metabolized sennoside B to sennidin B, suggesting that the sennoside-metabolizing bacteria produce a novel type of beta-glucosidase capable of hydrolyzing sennosides to sennidins. PMID:8161172

  1. An ATP Binding Cassette Transporter Mediates the Uptake of α-(1,6)-Linked Dietary Oligosaccharides in Bifidobacterium and Correlates with Competitive Growth on These Substrates.

    Science.gov (United States)

    Ejby, Morten; Fredslund, Folmer; Andersen, Joakim Mark; Vujičić Žagar, Andreja; Henriksen, Jonas Rosager; Andersen, Thomas Lars; Svensson, Birte; Slotboom, Dirk Jan; Abou Hachem, Maher

    2016-09-16

    The molecular details and impact of oligosaccharide uptake by distinct human gut microbiota (HGM) are currently not well understood. Non-digestible dietary galacto- and gluco-α-(1,6)-oligosaccharides from legumes and starch, respectively, are preferentially fermented by mainly bifidobacteria and lactobacilli in the human gut. Here we show that the solute binding protein (BlG16BP) associated with an ATP binding cassette (ABC) transporter from the probiotic Bifidobacterium animalis subsp. lactis Bl-04 binds α-(1,6)-linked glucosides and galactosides of varying size, linkage, and monosaccharide composition with preference for the trisaccharides raffinose and panose. This preference is also reflected in the α-(1,6)-galactoside uptake profile of the bacterium. Structures of BlG16BP in complex with raffinose and panose revealed the basis for the remarkable ligand binding plasticity of BlG16BP, which recognizes the non-reducing α-(1,6)-diglycoside in its ligands. BlG16BP homologues occur predominantly in bifidobacteria and a few Firmicutes but lack in other HGMs. Among seven bifidobacterial taxa, only those possessing this transporter displayed growth on α-(1,6)-glycosides. Competition assays revealed that the dominant HGM commensal Bacteroides ovatus was out-competed by B. animalis subsp. lactis Bl-04 in mixed cultures growing on raffinose, the preferred ligand for the BlG16BP. By comparison, B. ovatus mono-cultures grew very efficiently on this trisaccharide. These findings suggest that the ABC-mediated uptake of raffinose provides an important competitive advantage, particularly against dominant Bacteroides that lack glycan-specific ABC-transporters. This novel insight highlights the role of glycan transport in defining the metabolic specialization of gut bacteria. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  2. Control analysis of the role of triosephosphate isomerase in glucose metabolism in Lactococcus lactis

    DEFF Research Database (Denmark)

    Solem, Christian; Købmann, Brian Jensen; Jensen, Peter Ruhdal

    2008-01-01

    Triosephosphate isomerase (TPI), which catalyses the conversion of dihydroxyacetone phosphate (DHAP) to glyceraldehyde-3-phosphate (G3P), was studied for its control on glycolysis and mixed acid production in L. lactis subspecies lactis IL1403 and L. lactis subspecies cremoris MG1363. Strains...... metabolites glucose-6-phosphate, fructose-1,6-bisphosphate and DHAP in the IL1403 derivatives were essentially unchanged for TPI activities from 26% to 225%. At a TPI activity of 3%, the level of DHAP increased four times. The finding that an increased level of DHAP coincides with an increase in formate...

  3. Transcriptome profiling of Lactococcus lactis subsp. cremoris CECT 8666 in response to agmatine

    NARCIS (Netherlands)

    Del Rio, Beatriz; Redruello, Begoña; Martin, M Cruz; Fernandez, Maria; de Jong, Anne; Kuipers, Oscar P; Ladero, Victor; Alvarez, Miguel A

    2016-01-01

    The dairy strain Lactococcus lactis subsp. cremoris CECT 8666 (formerly GE2-14) synthesizes the biogenic amine putrescine from agmatine via the agmatine deiminase (AGDI) pathway [1]. The AGDI cluster of L. lactis is composed by five genes aguR, aguB, aguD, aguA and aguC. The last four genes are

  4. Cellodextrin utilization by bifidobacterium breve UCC2003.

    NARCIS (Netherlands)

    Pokusaeva, K.; Motherway, M.O.; Zomer, A.L.; Macsharry, J.; Fitzgerald, G.F.; Sinderen, D. van

    2011-01-01

    Cellodextrins, the incomplete hydrolysis products from insoluble cellulose, are accessible as a carbon source to certain members of the human gut microbiota, such as Bifidobacterium breve UCC2003. Transcription of the cldEFGC gene cluster of B. breve UCC2003 was shown to be induced upon growth on

  5. Role of some selected Bifidobacterium strains in modulating immunosenescence of aged albino rats

    Directory of Open Access Journals (Sweden)

    Hanan A. El-Bakry

    2013-10-01

    Full Text Available Probiotic administration has been associated with enhanced immune function in elderly subjects. However, approaches for selection of an “ideal” strain of bifidobacteria are still difficult. The aim of the present study is to investigate the possible modulatory effects of three strains of Bifidobacterium species (Bifidobacterium adolescentis ATCC 15704, Bifidobacterium breve ATCC 15700 and Bifidobacterium longum ATCC 15707 on haematological and immunological parameters of aged albino rats corresponding to normal adult ones. The animals were divided into six groups; three groups of aged rats were fed yoghurt inoculated with one of the Bifidobacterium strains; one group of aged rats was fed yoghurt alone (control aged; two groups of adult and aged rats were provided with normal diet and assigned as normal groups. The total leucocyte count was significantly increased in the three bifidobacteria-treated aged groups as compared with both normal and control aged rats. Serum IgA level was considerably increased in all treated rats. On the contrary, serum IgE level was significantly decreased in rats supplemented with yoghurt inoculated with B. adolescentis or B. breve. Both B. adolescentis and B. breve groups showed significant enhanced production of TNF-α. Furthermore, the production of cytokine IL-8 was significantly increased in the B. adolescentis group. Interestingly, it was apparent that only B. adolescentis had the most pronounced effect on aged rats to regain nearly normal values as measured in normal adult rats. Conclusively, the present work indicates that dietary consumption of selected bifidobacteria strains may have a particular application in the elderly especially in terms of immunomodulation.

  6. Characterization of a Lactococcus lactis promoter for heterologous protein production

    Directory of Open Access Journals (Sweden)

    Christian E. Ogaugwu

    2018-03-01

    Full Text Available Constitutively active promoter elements for heterologous protein production in Lactococcus lactis are scarce. Here, the promoter of the PTS-IIC gene cluster from L. lactis NZ3900 is described. This promoter was cloned upstream of an enhanced green fluorescent protein, GFPmut3a, and transformed into L. lactis. Transformants produced up to 13.5 μg of GFPmut3a per milliliter of log phase cells. Addition of cellobiose further increased the production of GFPmut3a by up to two-fold when compared to glucose. Analysis of mutations at two specific positions in the PTS-IIC promoter showed that a ‘T’ to ‘G’ mutation within the −35 element resulted in constitutive expression in glucose, while a ‘C’ at nucleotide 7 in the putative cre site enhanced promoter activity in cellobiose. Finally, this PTS-IIC promoter is capable of mediating protein expression in Bacillus subtilis and Escherichia coli Nissle 1917, suggesting the potential for future biotechnological applications of this element and its derivatives.

  7. Riboflavin Production in Lactococcus lactis: Potential for In Situ Production of Vitamin-Enriched Foods

    Science.gov (United States)

    Burgess, Catherine; O'Connell-Motherway, Mary; Sybesma, Wilbert; Hugenholtz, Jeroen; van Sinderen, Douwe

    2004-01-01

    This study describes the genetic analysis of the riboflavin (vitamin B2) biosynthetic (rib) operon in the lactic acid bacterium Lactococcus lactis subsp. cremoris strain NZ9000. Functional analysis of the genes of the L. lactis rib operon was performed by using complementation studies, as well as by deletion analysis. In addition, gene-specific genetic engineering was used to examine which genes of the rib operon need to be overexpressed in order to effect riboflavin overproduction. Transcriptional regulation of the L. lactis riboflavin biosynthetic process was investigated by using Northern hybridization and primer extension, as well as the analysis of roseoflavin-induced riboflavin-overproducing L. lactis isolates. The latter analysis revealed the presence of both nucleotide replacements and deletions in the regulatory region of the rib operon. The results presented here are an important step toward the development of fermented foods containing increased levels of riboflavin, produced in situ, thus negating the need for vitamin fortification. PMID:15466513

  8. The Plasmid Complement of Lactococcus lactis UC509.9 Encodes Multiple Bacteriophage Resistance Systems

    Science.gov (United States)

    Ainsworth, Stuart; Mahony, Jennifer

    2014-01-01

    Lactococcus lactis subsp. cremoris strains are used globally for the production of fermented dairy products, particularly hard cheeses. Believed to be of plant origin, L. lactis strains that are used as starter cultures have undergone extensive adaptation to the dairy environment, partially through the acquisition of extrachromosomal DNA in the form of plasmids that specify technologically important phenotypic traits. Here, we present a detailed analysis of the eight plasmids of L. lactis UC509.9, an Irish dairy starter strain. Key industrial phenotypes were mapped, and genes that are typically associated with lactococcal plasmids were identified. Four distinct, plasmid-borne bacteriophage resistance systems were identified, including two abortive infection systems, AbiB and AbiD1, thereby supporting the observed phage resistance of L. lactis UC509.9. AbiB escape mutants were generated for phage sk1, which were found to carry mutations in orf6, which encodes the major capsid protein of this phage. PMID:24814781

  9. Production of the small heat shock protein Lo18 from Oenococcus oeni in Lactococcus lactis improves its stress tolerance.

    Science.gov (United States)

    Weidmann, Stéphanie; Maitre, Magali; Laurent, Julie; Coucheney, Françoise; Rieu, Aurélie; Guzzo, Jean

    2017-04-17

    Lactococcus lactis is a lactic acid bacterium widely used in cheese and fermented milk production. During fermentation, L. lactis is subjected to acid stress that impairs its growth. The small heat shock protein (sHsp) Lo18 from the acidophilic species Oenococcus oeni was expressed in L. lactis. This sHsp is known to play an important role in protein protection and membrane stabilization in O. oeni. The role of this sHsp could be studied in L. lactis, since no gene encoding for sHsp has been detected in this species. L. lactis subsp. cremoris strain MG1363 was transformed with the pDLhsp18 plasmid, which is derived from pDL278 and contains the hsp18 gene (encoding Lo18) and its own promoter sequence. The production of Lo18 during stress conditions was checked by immunoblotting and the cellular distribution of Lo18 in L. lactis cells after heat shock was determined. Our results clearly indicated a role for Lo18 in cytoplasmic protein protection and membrane stabilization during stress. The production of sHsp in L. lactis improved tolerance to heat and acid conditions in this species. Finally, the improvement of the L. lactis survival in milk medium thanks to Lo18 was highlighted, suggesting an interesting role of this sHsp. These findings suggest that the expression of a sHsp by a L. lactis strain results in greater resistance to stress, and, can consequently enhance the performances of industrial strains. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Interaction between the genomes of Lactococcus lactis and phages of the P335 species

    Science.gov (United States)

    Kelly, William J.; Altermann, Eric; Lambie, Suzanne C.; Leahy, Sinead C.

    2013-01-01

    Phages of the P335 species infect Lactococcus lactis and have been particularly studied because of their association with strains of L. lactis subsp. cremoris used as dairy starter cultures. Unlike other lactococcal phages, those of the P335 species may have a temperate or lytic lifestyle, and are believed to originate from the starter cultures themselves. We have sequenced the genome of L. lactis subsp. cremoris KW2 isolated from fermented corn and found that it contains an integrated P335 species prophage. This 41 kb prophage (Φ KW2) has a mosaic structure with functional modules that are highly similar to several other phages of the P335 species associated with dairy starter cultures. Comparison of the genomes of 26 phages of the P335 species, with either a lytic or temperate lifestyle, shows that they can be divided into three groups and that the morphogenesis gene region is the most conserved. Analysis of these phage genomes in conjunction with the genomes of several L. lactis strains shows that prophage insertion is site specific and occurs at seven different chromosomal locations. Exactly how induced or lytic phages of the P335 species interact with carbohydrate cell surface receptors in the host cell envelope remains to be determined. Genes for the biosynthesis of a variable cell surface polysaccharide and for lipoteichoic acids (LTAs) are found in L. lactis and are the main candidates for phage receptors, as the genes for other cell surface carbohydrates have been lost from dairy starter strains. Overall, phages of the P335 species appear to have had only a minor role in the adaptation of L. lactis subsp. cremoris strains to the dairy environment, and instead they appear to be an integral part of the L. lactis chromosome. There remains a great deal to be discovered about their role, and their contribution to the evolution of the bacterial genome. PMID:24009606

  11. Metabolism of Sialic Acid by Bifidobacterium breve UCC2003

    Science.gov (United States)

    Egan, Muireann; O'Connell Motherway, Mary; Ventura, Marco

    2014-01-01

    Bifidobacteria constitute a specific group of commensal bacteria that inhabit the gastrointestinal tracts of humans and other mammals. Bifidobacterium breve UCC2003 has previously been shown to utilize several plant-derived carbohydrates that include cellodextrins, starch, and galactan. In the present study, we investigated the ability of this strain to utilize the mucin- and human milk oligosaccharide (HMO)-derived carbohydrate sialic acid. Using a combination of transcriptomic and functional genomic approaches, we identified a gene cluster dedicated to the uptake and metabolism of sialic acid. Furthermore, we demonstrate that B. breve UCC2003 can cross feed on sialic acid derived from the metabolism of 3′-sialyllactose, an abundant HMO, by another infant gut bifidobacterial strain, Bifidobacterium bifidum PRL2010. PMID:24814790

  12. Immunization against Leishmania major infection using LACK- and IL-12-expressing Lactococcus lactis induces delay in footpad swelling.

    Directory of Open Access Journals (Sweden)

    Felix Hugentobler

    Full Text Available BACKGROUND: Leishmania is a mammalian parasite affecting over 12 million individuals worldwide. Current treatments are expensive, cause severe side effects, and emerging drug resistance has been reported. Vaccination is the most cost-effective means to control infectious disease but currently there is no vaccine available against Leishmaniasis. Lactococcus lactis is a non-pathogenic, non-colonizing Gram-positive lactic acid bacterium commonly used in the dairy industry. Recently, L. lactis was used to express biologically active molecules including vaccine antigens and cytokines. METHODOLOGY/PRINCIPAL FINDINGS: We report the generation of L. lactis strains expressing the protective Leishmania antigen, LACK, in the cytoplasm, secreted or anchored to the bacterial cell wall. L. lactis was also engineered to secrete biologically active single chain mouse IL-12. Subcutaneous immunization with live L. lactis expressing LACK anchored to the cell wall and L. lactis secreting IL-12 significantly delayed footpad swelling in Leishmania major infected BALB/c mice. The delay in footpad swelling correlated with a significant reduction of parasite burden in immunized animals compared to control groups. Immunization with these two L. lactis strains induced antigen-specific multifunctional T(H1 CD4(+ and CD8(+ T cells and a systemic LACK-specific T(H1 immune response. Further, protection in immunized animals correlated with a Leishmania-specific T(H1 immune response post-challenge. L. lactis secreting mouse IL-12 was essential for directing immune responses to LACK towards a protective T(H1 response. CONCLUSIONS/SIGNIFICANCE: This report demonstrates the use of L. lactis as a live vaccine against L. major infection in BALB/c mice. The strains generated in this study provide the basis for the development of an inexpensive and safe vaccine against the human parasite Leishmania.

  13. Immunization against Leishmania major Infection Using LACK- and IL-12-Expressing Lactococcus lactis Induces Delay in Footpad Swelling

    Science.gov (United States)

    Hugentobler, Felix; Yam, Karen K.; Gillard, Joshua; Mahbuba, Raya; Olivier, Martin; Cousineau, Benoit

    2012-01-01

    Background Leishmania is a mammalian parasite affecting over 12 million individuals worldwide. Current treatments are expensive, cause severe side effects, and emerging drug resistance has been reported. Vaccination is the most cost-effective means to control infectious disease but currently there is no vaccine available against Leishmaniasis. Lactococcus lactis is a non-pathogenic, non-colonizing Gram-positive lactic acid bacterium commonly used in the dairy industry. Recently, L. lactis was used to express biologically active molecules including vaccine antigens and cytokines. Methodology/Principal findings We report the generation of L. lactis strains expressing the protective Leishmania antigen, LACK, in the cytoplasm, secreted or anchored to the bacterial cell wall. L. lactis was also engineered to secrete biologically active single chain mouse IL-12. Subcutaneous immunization with live L. lactis expressing LACK anchored to the cell wall and L. lactis secreting IL-12 significantly delayed footpad swelling in Leishmania major infected BALB/c mice. The delay in footpad swelling correlated with a significant reduction of parasite burden in immunized animals compared to control groups. Immunization with these two L. lactis strains induced antigen-specific multifunctional TH1 CD4+ and CD8+ T cells and a systemic LACK-specific TH1 immune response. Further, protection in immunized animals correlated with a Leishmania-specific TH1 immune response post-challenge. L. lactis secreting mouse IL-12 was essential for directing immune responses to LACK towards a protective TH1 response. Conclusions/Significance This report demonstrates the use of L. lactis as a live vaccine against L. major infection in BALB/c mice. The strains generated in this study provide the basis for the development of an inexpensive and safe vaccine against the human parasite Leishmania. PMID:22348031

  14. Bacteriocinogenic Lactococcus lactis subsp. lactis DF04Mi isolated from goat milk: Application in the control of Listeria monocytogenes in fresh Minas-type goat cheese

    Directory of Open Access Journals (Sweden)

    Danielle N. Furtado

    2015-03-01

    Full Text Available Listeria monocytogenes is a pathogen frequently found in dairy products. Its control in fresh cheeses is difficult, due to the psychrotrophic properties and salt tolerance. Bacteriocinogenic lactic acid bacteria (LAB with proven in vitro antilisterial activity can be an innovative technological approach but their application needs to be evaluated by means of in situ tests. In this study, a novel bacteriocinogenic Lactococcus lactis strain (Lc. lactis DF4Mi, isolated from raw goat milk, was tested for control of growth of L. monocytogenes in artificially contaminated fresh Minas type goat cheese during storage under refrigeration. A bacteriostatic effect was achieved, and counts after 10 days were 3 log lower than in control cheeses with no added LAB. However, this effect did not differ significantly from that obtained with a non-bacteriocinogenic Lc. lactis strain. Addition of nisin (12.5 mg/kg caused a rapid decrease in the number of viable L. monocytogenes in the cheeses, suggesting that further studies with the purified bacteriocin DF4Mi may open new possibilities for this strain as biopreservative in dairy products.

  15. Transcriptomic profile of aguR deletion mutant of Lactococcus lactis subsp. cremoris CECT 8666

    NARCIS (Netherlands)

    Del Rio, Beatriz; Linares, Daniel M; Redruello, Begoña; Martin, Maria Cruz; Fernandez, Maria; de Jong, Anne; Kuipers, Oscar P; Ladero, Victor; Alvarez, Miguel A

    2015-01-01

    Lactococcus lactis subsp. cremoris CECT 8666 (formerly GE2-14) is a dairy strain that catabolizes agmatine (a decarboxylated derivative of arginine) into the biogenic amine putrescine by the agmatine deiminase (AGDI) pathway [1]. The AGDI cluster of L. lactis is composed by five genes aguR, aguB,

  16. Efficiency of PCR-based methods in discriminating Bifidobacterium longum ssp. longum and Bifidobacterium longum ssp. infantis strains of human origin

    Czech Academy of Sciences Publication Activity Database

    Šrůtková, Dagmar; Španová, A.; Špano, M.; Dráb, V.; Schwarzer, Martin; Kozáková, Hana; Rittich, B.

    2011-01-01

    Roč. 87, č. 1 (2011), s. 10-16 ISSN 0167-7012 R&D Projects: GA MŠk 2B06053 Institutional research plan: CEZ:AV0Z50200510 Keywords : Bifidobacterium longum * ARDRA * pcr Subject RIV: EC - Immunology Impact factor: 2.086, year: 2011

  17. Digastric Muscle Phenotypes of the Ts65Dn Mouse Model of Down Syndrome.

    Directory of Open Access Journals (Sweden)

    Tiffany J Glass

    Full Text Available Down syndrome is frequently associated with complex difficulties in oromotor development, feeding, and swallowing. However, the muscle phenotypes underlying these deficits are unclear. We tested the hypotheses that the Ts65Dn mouse model of DS has significantly altered myosin heavy chain (MyHC isoform profiles of the muscles involved in feeding and swallowing, as well as reductions in the speed of these movements during behavioral assays. SDS-PAGE, immunofluorescence, and qRT-PCR were used to assess MyHC isoform expression in pertinent muscles, and functional feeding and swallowing performance were quantified through videofluoroscopy and mastication assays. We found that both the anterior digastric (ADG and posterior digastric (PDG muscles in 11-day old and 5-6 week old Ts65Dn groups showed significantly lower MyHC 2b protein levels than in age-matched euploid control groups. In videofluoroscopic and videotape assays used to quantify swallowing and mastication performance, 5-6 week old Ts65Dn and euploid controls showed similar swallow rates, inter-swallow intervals, and mastication rates. In analysis of adults, 10-11 week old Ts65Dn mice revealed significantly less MyHC 2b mRNA expression in the posterior digastric, but not the anterior digastric muscle as compared with euploid controls. Analysis of MyHC 2b protein levels across an adult age range (10-53 weeks of age revealed lower levels of MyHC 2b protein in the PDG of Ts65Dn than in euploids, but similar levels of MyHC 2b in the ADG. Cumulatively, these results indicate biochemical differences in some, but not all, muscles involved in swallowing and jaw movement in Ts65Dn mice that manifest early in post-natal development, and persist into adulthood. These findings suggest potential utility of this model for future investigations of the mechanisms of oromotor difficulties associated with Down syndrome.

  18. Surface Proteins of Lactococcus lactis: Bacterial Resources for Muco-adhesion in the Gastrointestinal Tract

    Directory of Open Access Journals (Sweden)

    Muriel Mercier-Bonin

    2017-11-01

    Full Text Available Food and probiotic bacteria, in particular lactic acid bacteria, are ingested in large amounts by humans and are part of the transient microbiota which is increasingly considered to be able to impact the resident microbiota and thus possibly the host health. The lactic acid bacterium Lactococcus lactis is extensively used in starter cultures to produce dairy fermented food. Also because of a generally recognized as safe status, L. lactis has been considered as a possible vehicle to deliver in vivo therapeutic molecules with anti-inflammatory properties in the gastrointestinal tract. One of the key factors that may favor health effects of beneficial bacteria to the host is their capacity to colonize transiently the gut, notably through close interactions with mucus, which covers and protects the intestinal epithelium. Several L. lactis strains have been shown to exhibit mucus-binding properties and bacterial surface proteins have been identified as key determinants of such capacity. In this review, we describe the different types of surface proteins found in L. lactis, with a special focus on mucus-binding proteins and pili. We also review the different approaches used to investigate the adhesion of L. lactis to mucus, and particularly to mucins, one of its major components, and we present how these approaches allowed revealing the role of surface proteins in muco-adhesion.

  19. Analysis of heat shock gene expression in Lactococcus lactis MG1363

    DEFF Research Database (Denmark)

    Arnau, José; Sørensen, Kim; Appel, Karen Fuglede

    1996-01-01

    The induction of the heat shock response in Lactococcus lactis subsp. cremoris strain MG1363 was analysed at the RNA level using a novel RNA isolation procedure to prevent degradation. Cloning of the dnaJ and groEL homologous was carried out. Nothern blot analysis showed a similar induction pattern...... in the heat shock response in L. lactis MG1363 is presented. A gene located downstream of the dnaK operon in strain MG1363, named orf4, was shown not to be regulated by heat shock....

  20. Transcriptome analysis of the Lactococcus lactis ArgR and AhrC regulons

    DEFF Research Database (Denmark)

    Larsen, Rasmus; van Hijum, Sacha A. F. T.; Martinussen, Jan

    2008-01-01

    In previous studies, we have shown that direct protein-protein. interaction between the two regulators ArgR and AhrC in Lactococcus lactis is required for arginine-dependent repression of the biosynthetic argC promoter and the activation of the catabolic arcA promoter. Here, we establish the global...... ArgR and AhrC regulons by transcriptome analyses and show that both regulators are dedicated to the control of arginine metabolism in L. lactis....

  1. A role for E2-2 at the DN3 stage of early thymopoiesis

    DEFF Research Database (Denmark)

    Wikström, Ingela; Forssell, Johan; Penha-Goncalves, Mario N

    2008-01-01

    Roles for the E-proteins E2A and HEB during T lymphocyte development have been well established. Based on our previous observations of counter selection against T cells lacking E2-2, it seemed reasonable to assume that there would be a function also for E2-2 in thymocyte development. Aiming...... proteins, Id2 displayed a prominent expression exclusively in DN1, whereas Id3 showed some expression in DN1, followed by a down regulation and then a prominent induction, peaking in the DP stage. E2-2 was expressed during the DN stages, as well as in the DP stage, suggesting that E2-2 operates in concert...

  2. A mouse mastitis model to study the effects of the intramammary infusion of a food-grade Lactococcus lactis strain.

    Directory of Open Access Journals (Sweden)

    Cristina Camperio

    Full Text Available Lactococcus lactis is one of the most important microorganisms in the dairy industry and has "generally recognized as safe" (GRAS status. L. lactis belongs to the group of lactic acid bacteria (LAB and is encountered in a wide range of environments. Recently, the use of the intramammary infusion of a live culture of LAB has been investigated as a new antibiotic alternative for treating mastitis in dairy ruminants. Controversial results are described in literature regarding its efficacy and safety. In this study we conducted in-depth investigation of the mammary gland immune response induced by intramammary inoculum of a live culture of L. lactis LMG 7930 using the mouse mastitis model. Overnight cultures either of L. lactis (≈ 107 CFU or of the mastitis pathogens Staphylococcus chromogenes (≈ 105 CFU or S. aureus (≈ 102 CFU/ml were injected into the mouse inguinal glands. A double injection, consisting of S. chromogenes first and then L. lactis, was also investigated. Bacterial recovery from the gland and inflammatory cell infiltration were assessed. L. lactis-treated and control glands were analysed for proinflammatory cytokine production. Microbiological results showed that L. lactis was able to survive in the mammary gland 24 h post infection, as were the mastitis pathogens S. chromogenes and S. aureus. L. lactis reduced S. chromogenes survival in the glands and increased its own survival ability by coexisting with the pathogen. Histology showed that L. lactis-treated glands presented variable histological features, ranging from undamaged tissue with no inflammatory cell infiltrate to severe PMN infiltrate with focal areas of tissue damage. S. aureus-treated glands showed the most severe histological grade of inflammation despite the fact that the inoculum size was the smallest. In contrast, most S. chromogenes-treated glands showed normal structures with no infiltration or lesions. Significant increases in IL-1β and TNF-α levels were

  3. A mouse mastitis model to study the effects of the intramammary infusion of a food-grade Lactococcus lactis strain

    Science.gov (United States)

    Biasibetti, Elena; Frassanito, Paolo; Giovannelli, Carlo; Spuria, Liliana; D’Agostino, Claudia; Tait, Sabrina; Capucchio, Maria Teresa

    2017-01-01

    Lactococcus lactis is one of the most important microorganisms in the dairy industry and has “generally recognized as safe” (GRAS) status. L. lactis belongs to the group of lactic acid bacteria (LAB) and is encountered in a wide range of environments. Recently, the use of the intramammary infusion of a live culture of LAB has been investigated as a new antibiotic alternative for treating mastitis in dairy ruminants. Controversial results are described in literature regarding its efficacy and safety. In this study we conducted in-depth investigation of the mammary gland immune response induced by intramammary inoculum of a live culture of L. lactis LMG 7930 using the mouse mastitis model. Overnight cultures either of L. lactis (≈ 107 CFU) or of the mastitis pathogens Staphylococcus chromogenes (≈ 105 CFU) or S. aureus (≈ 102 CFU/ml) were injected into the mouse inguinal glands. A double injection, consisting of S. chromogenes first and then L. lactis, was also investigated. Bacterial recovery from the gland and inflammatory cell infiltration were assessed. L. lactis-treated and control glands were analysed for proinflammatory cytokine production. Microbiological results showed that L. lactis was able to survive in the mammary gland 24 h post infection, as were the mastitis pathogens S. chromogenes and S. aureus. L. lactis reduced S. chromogenes survival in the glands and increased its own survival ability by coexisting with the pathogen. Histology showed that L. lactis-treated glands presented variable histological features, ranging from undamaged tissue with no inflammatory cell infiltrate to severe PMN infiltrate with focal areas of tissue damage. S. aureus-treated glands showed the most severe histological grade of inflammation despite the fact that the inoculum size was the smallest. In contrast, most S. chromogenes-treated glands showed normal structures with no infiltration or lesions. Significant increases in IL-1β and TNF-α levels were also found

  4. A mouse mastitis model to study the effects of the intramammary infusion of a food-grade Lactococcus lactis strain.

    Science.gov (United States)

    Camperio, Cristina; Armas, Federica; Biasibetti, Elena; Frassanito, Paolo; Giovannelli, Carlo; Spuria, Liliana; D'Agostino, Claudia; Tait, Sabrina; Capucchio, Maria Teresa; Marianelli, Cinzia

    2017-01-01

    Lactococcus lactis is one of the most important microorganisms in the dairy industry and has "generally recognized as safe" (GRAS) status. L. lactis belongs to the group of lactic acid bacteria (LAB) and is encountered in a wide range of environments. Recently, the use of the intramammary infusion of a live culture of LAB has been investigated as a new antibiotic alternative for treating mastitis in dairy ruminants. Controversial results are described in literature regarding its efficacy and safety. In this study we conducted in-depth investigation of the mammary gland immune response induced by intramammary inoculum of a live culture of L. lactis LMG 7930 using the mouse mastitis model. Overnight cultures either of L. lactis (≈ 107 CFU) or of the mastitis pathogens Staphylococcus chromogenes (≈ 105 CFU) or S. aureus (≈ 102 CFU/ml) were injected into the mouse inguinal glands. A double injection, consisting of S. chromogenes first and then L. lactis, was also investigated. Bacterial recovery from the gland and inflammatory cell infiltration were assessed. L. lactis-treated and control glands were analysed for proinflammatory cytokine production. Microbiological results showed that L. lactis was able to survive in the mammary gland 24 h post infection, as were the mastitis pathogens S. chromogenes and S. aureus. L. lactis reduced S. chromogenes survival in the glands and increased its own survival ability by coexisting with the pathogen. Histology showed that L. lactis-treated glands presented variable histological features, ranging from undamaged tissue with no inflammatory cell infiltrate to severe PMN infiltrate with focal areas of tissue damage. S. aureus-treated glands showed the most severe histological grade of inflammation despite the fact that the inoculum size was the smallest. In contrast, most S. chromogenes-treated glands showed normal structures with no infiltration or lesions. Significant increases in IL-1β and TNF-α levels were also found in

  5. Formation and conversion of oxygen metabolites by Lactococcus lactis subsp lactis ATCC 19435 under different growth conditions

    NARCIS (Netherlands)

    Niel, van E.W.J.; Hofvendahl, K.; Hahn Hagerdal, B.

    2002-01-01

    A semidefined medium based on Casamino Acids allowed Lactococcus lactis ATCC 19435 to grow in the presence of oxygen at a slow rate (0.015 h-1). Accumulation of H2O2 in the culture prevented a higher growth rate. Addition of asparagine to the medium increased the growth rate, whereby H2O2

  6. Iogurte probiótico produzido com leite de cabra suplementado com Bifidobacterium spp

    Directory of Open Access Journals (Sweden)

    V Mazochi

    2010-12-01

    Full Text Available Avaliaram-se iogurtes de leite de cabra contendo ou não Bifidobacterium longum, B. breve, B. pseudolongum ou B. bifidum, adicionados ou não de aroma de morango. Os dados obtidos nas análises higiênico-sanitárias e físico-químicas foram dentro dos valores exigidos pela legislação brasileira; apenas o valor encontrado para lactose esteve abaixo do recomendado. Quanto às bactérias do iogurte, não houve diferença na contagem de Streptococcus salivarius subsp. thermophilus durante a estocagem, e não foi detectado Lactobacillus delbrueckii subsp. bulgaricus nas diluições utilizadas. A enumeração de Bifidobacterium spp. manteve-se entre 10(6 e 10(8UFC/mL e não diferiu entre as espécies ao longo do tempo. Considerando-se a adição ou não de aroma, a análise das variáveis tempo e aroma não mostrou diferença estatística. A contagem entre os Bifidobacterium spp. demonstrou que nenhum microrganismo apresentou um comportamento superior a outro. Na análise sensorial, as amostras de iogurtes adicionados ou não de Bifidobacterium spp. e adicionados de aroma de morango não apresentaram diferenças entre si. O estudo mostrou ser possível a elaboração de iogurte de leite de cabra adicionado de Bifidobacterium spp. e de aroma de morango com qualidade assegurada, potencial para uso probiótico e boa aceitação pelo consumidor.

  7. Effects of metal ions on growth, β-oxidation system, and thioesterase activity of Lactococcus lactis.

    Science.gov (United States)

    Li, Liang; Ma, Ying

    2014-10-01

    The effects of divalent metal ions (Ca(2+), Mg(2+), Fe(2+), and Cu(2+)) on the growth, β-oxidation system, and thioesterase activity of Lactococcus lactis were investigated. Different metal ions significantly influenced the growth of L. lactis: Ca(2+) and Fe(2+) accelerated growth, whereas Cu(2+) inhibited growth. Furthermore, Mg(2+) inhibited growth of L. lactis at a low concentration but stimulated growth of L. lactis at a high concentration. The divalent metal ions had significant effects on activity of the 4 key enzymes of the β-oxidation system (acyl-CoA dehydrogenase, enoyl-CoA hydratase, L-3-hydroxyacyl-CoA dehydrogenase, and thiolase) and thioesterase of L. lactis. The activity of acyl-CoA dehydrogenases increased markedly in the presence of Ca(2+) and Mg(2+), whereas it decreased with 1 mmol/L Fe(2+) or 12 mmol/L Mg(2+). All the metal ions could induce activity of enoyl-CoA hydratase. In addition, 12 mmol/L Mg(2+) significantly stimulated activity of L-3-hydroxyacyl-CoA dehydrogenase, and all metal ions could induce activity of thiolase, although thiolase activity decreased significantly when 0.05 mmol/L Cu(2+) was added into M17 broth. Inhibition of thioesterase activity by all 4 metal ions could be reversed by 2 mmol/L Ca(2+). These results help us understand the effect of metal ions on the β-oxidation system and thioesterase activity of Lactococcus lactis. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  8. Endosomal recognition of Lactococcus lactis G121 and its RNA by dendritic cells is key to its allergy-protective effects.

    Science.gov (United States)

    Stein, Karina; Brand, Stephanie; Jenckel, André; Sigmund, Anna; Chen, Zhijian James; Kirschning, Carsten J; Kauth, Marion; Heine, Holger

    2017-02-01

    Bacterial cowshed isolates are allergy protective in mice; however, the underlying mechanisms are largely unknown. We examined the ability of Lactococcus lactis G121 to prevent allergic inflammatory reactions. We sought to identify the ligands and pattern recognition receptors through which L lactis G121 confers allergy protection. L lactis G121-induced cytokine release and surface expression of costimulatory molecules by untreated or inhibitor-treated (bafilomycin and cytochalasin D) human monocyte-derived dendritic cells (moDCs), bone marrow-derived mouse dendritic cells (BMDCs), and moDC/naive CD4 + T-cell cocultures were analyzed by using ELISA and flow cytometry. The pathology of ovalbumin-induced acute allergic airway inflammation after adoptive transfer of BMDCs was examined by means of microscopy. L lactis G121-treated murine BMDCs and human moDCs released T H 1-polarizing cytokines and induced T H 1 T cells. Inhibiting phagocytosis and endosomal acidification in BMDCs or moDCs impaired the release of T H 1-polarizing cytokines, costimulatory molecule expression, and T-cell activation on L lactis G121 challenge. In vivo allergy protection mediated by L lactis G121 was dependent on endosomal acidification in dendritic cells (DCs). Toll-like receptor (Tlr) 13 -/- BMDCs showed a weak response to L lactis G121 and were unresponsive to its RNA. The T H 1-polarizing activity of L lactis G121-treated human DCs was blocked by TLR8-specific inhibitors, mediated by L lactis G121 RNA, and synergistically enhanced by activation of nucleotide-binding oligomerization domain-containing protein (NOD) 2. Bacterial RNA is the main driver of L lactis G121-mediated protection against experimentally induced allergy and requires both bacterial uptake by DCs and endosomal acidification. In mice L lactis G121 RNA signals through TLR13; however, the most likely intracellular receptor in human subjects is TLR8. Copyright © 2016 American Academy of Allergy, Asthma & Immunology

  9. Probiotic Lactococcus lactis: A Review

    OpenAIRE

    Priti Khemariya; Sudhir Singh; Gopal Nath; Anil K Gulati

    2017-01-01

    Lactococcus lactis plays a critical role in food, dairy and health sectors. In food and dairy industries, it is found in production processes of various fermented products such as sausages, pickled vegetables, beverages such as beer and wine, breads, soymilk kefir, sour milk, butter, cream, fresh cheese and different types of cheeses, like Cheddar, Colby, Cottage cheese, Camembert, cream cheese, Roquefort and Brie. Additionally, there is an increasing interest towards the possible health bene...

  10. Anti-inflammatory properties of fermented soy milk with Lactococcus lactis subsp. lactis S-SU2 in murine macrophage RAW264.7 cells and DSS-induced IBD model mice.

    Science.gov (United States)

    Kawahara, Miho; Nemoto, Maki; Nakata, Toru; Kondo, Saya; Takahashi, Hajime; Kimura, Bon; Kuda, Takashi

    2015-06-01

    Six lactic acid bacteria strains (four Lactobacillus plantarum strains and one each of Lactococcus lactis subsp. lactis and Pediococcus pentosaceus) have been isolated and shown to possess anti-oxidant activity. In this study, we determined their acid, bile, salt resistance, and adhesion activity on human enterocyte-like HT-29-Luc and Caco-2 cells. An isolate Lc. lactis S-SU2 showed highest bile resistance and adhesion activity compared to type strains. S-SU2 could ferment both 10% skimmed milk and soy milk while the type strain could not ferment soy milk. Soy milk fermented with S-SU2 showed an increased nitric oxide (NO) secretion in the mouse macrophage RAW264.7 cells without bacterial lipopolysaccharide (LPS). Furthermore, the inhibitory effects of the fermented soy milk on Escherichia coli O111 LPS-induced NO secretion were higher than those of fresh soy milk. Inflammatory bowel disease (IBD) was induced in mice fed either 5% (w/v) dextran sodium sulfate (DSS) in drinking water or 50% soy milk in drinking water. Shortening of colon length, breaking of epithelial cells, lowering liver and thymus weights, and enlargement of spleen are some of the characteristics observed in the IBD, which were prevented by the use of soy milk fermented with Lc. lactis S-SU2. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Lactococcus lactis expressing either Staphylococcus aureus fibronectin-binding protein A or Listeria monocytogenes internalin A can efficiently internalize and deliver DNA in human epithelial cells.

    Science.gov (United States)

    Innocentin, Silvia; Guimarães, Valeria; Miyoshi, Anderson; Azevedo, Vasco; Langella, Philippe; Chatel, Jean-Marc; Lefèvre, François

    2009-07-01

    Lactococci are noninvasive bacteria frequently used as protein delivery vectors and, more recently, as in vitro and in vivo DNA delivery vehicles. We previously showed that a functional eukaryotic enhanced green fluorescent protein (eGFP) expression plasmid vector was delivered in epithelial cells by Lactococcus lactis producing Listeria monocytogenes internalin A (L. lactis InlA(+)), but this strategy is limited in vivo to transgenic mice and guinea pigs. In this study, we compare the internalization ability of L. lactis InlA(+) and L. lactis producing either the fibronectin-binding protein A of Staphylococcus aureus (L. lactis FnBPA(+)) or its fibronectin binding domains C and D (L. lactis CD(+)). L. lactis FnBPA(+) and L. lactis InlA(+) showed comparable internalization rates in Caco-2 cells, while the internalization rate observed with L. lactis CD(+) was lower. As visualized by conventional and confocal fluorescence microscopy, large clusters of L. lactis FnBPA(+), L. lactis CD(+), and L. lactis InlA(+) were present in the cytoplasm of Caco-2 cells after internalization. Moreover, the internalization rates of Lactobacillus acidophilus NCFM and of an NCFM mutant strain with the gene coding for the fibronectin-binding protein (fbpA) inactivated were also evaluated in Caco-2 cells. Similar low internalization rates were observed for both wild-type L. acidophilus NCFM and the fbpA mutant, suggesting that commensal fibronectin binding proteins have a role in adhesion but not in invasion. L. lactis FnBPA(+), L. lactis CD(+), and L. lactis InlA(+) were then used to deliver a eukaryotic eGFP expression plasmid in Caco-2 cells: flow cytometry analysis showed that the highest percentage of green fluorescent Caco-2 cells was observed after coculture with either L. lactis FnBPA(+) or L. lactis InlA(+). Analysis of the in vivo efficiency of these invasive recombinant strains is currently in progress to validate their potential as DNA vaccine delivery vehicles.

  12. Metabolism of sialic acid by Bifidobacterium breve UCC2003.

    Science.gov (United States)

    Egan, Muireann; O'Connell Motherway, Mary; Ventura, Marco; van Sinderen, Douwe

    2014-07-01

    Bifidobacteria constitute a specific group of commensal bacteria that inhabit the gastrointestinal tracts of humans and other mammals. Bifidobacterium breve UCC2003 has previously been shown to utilize several plant-derived carbohydrates that include cellodextrins, starch, and galactan. In the present study, we investigated the ability of this strain to utilize the mucin- and human milk oligosaccharide (HMO)-derived carbohydrate sialic acid. Using a combination of transcriptomic and functional genomic approaches, we identified a gene cluster dedicated to the uptake and metabolism of sialic acid. Furthermore, we demonstrate that B. breve UCC2003 can cross feed on sialic acid derived from the metabolism of 3'-sialyllactose, an abundant HMO, by another infant gut bifidobacterial strain, Bifidobacterium bifidum PRL2010. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  13. RETRACTED: Relationship between the ACE I/D gene polymorphism and T1DN susceptibility/risk of T1DM developing into T1DN in the Caucasian population.

    Science.gov (United States)

    Zhou, Tian-Biao; Guo, Xue-Feng; Jiang, Zongpei; Li, Hong-Yan

    2015-12-01

    The following article has been included in a multiple retraction: Tian-Biao Zhou, Xue-Feng Guo, Zongpei Jiang, and Hong-Yan Li Relationship between the ACE I/D gene polymorphism and T1DN susceptibility/risk of T1DM developing into T1DN in the Caucasian population Journal of Renin-Angiotensin-Aldosterone System 1470320314563425, first published on February 1, 2015 doi: 10.1177/1470320314563425 This article has been retracted at the request of the Editors and the Publisher. After conducting a thorough investigation, SAGE found that the submitting authors of a number of papers published in the Journal of the Renin-Angiotensin Aldosterone System ( JRAAS) (listed below) had supplied fabricated contact details for their nominated reviewers. The Editors accepted these papers based on the reports supplied by the individuals using these fake reviewer email accounts. After concluding that the peer review process was therefore seriously compromised, SAGE and the journal Editors have decided to retract all affected articles. Online First articles (these articles will not be published in an issue) Wenzhuang Tang, Tian-Biao Zhou, and Zongpei Jiang Association of the angiotensinogen M235T gene polymorphism with risk of diabetes mellitus developing into diabetic nephropathy Journal of Renin-Angiotensin-Aldosterone System 1470320314563426, first published on December 18, 2014 doi: 10.1177/1470320314563426 Tian-Biao Zhou, Hong-Yan Li, Zong-Pei Jiang, Jia-Fan Zhou, Miao-Fang Huang, and Zhi-Yang Zhou Role of renin-angiotensin-aldosterone system inhibitors in radiation nephropathy Journal of Renin-Angiotensin-Aldosterone System 1470320314563424, first published on December 18, 2014 doi: 10.1177/1470320314563424 Weiqiang Zhong, Zongpei Jiang, and Tian-Biao Zhou Association between the ACE I/D gene polymorphism and T2DN susceptibility: The risk of T2DM developing into T2DN in the Asian population Journal of Renin-Angiotensin-Aldosterone System 1470320314566019, first published on January

  14. Detection of bacteriophage-infected cells of Lactococcus lactis using flow cytometry

    DEFF Research Database (Denmark)

    Michelsen, Ole; Cuesta-Dominguez, Álvaro; Albrektsen, Bjarne

    2007-01-01

    Bacteriophage infection in dairy fermentation constitutes a serious problem worldwide. We have studied bacteriophage infection in Lactococcus lactis by using the flow cytometer. The first effect of the infection of the bacterium is a change from cells in chains toward single cells. We interpret...... describe a new method for detection of phage infection in Lactococcus lactis dairy cultures. The method is based on flow cytometric detection of cells with low-density cell walls. The method allows fast and early detection of phage-infected bacteria, independently of which phage has infected the culture...

  15. Different effects of two newly-isolated probiotic Lactobacillus plantarum 15HN and Lactococcus lactis subsp. Lactis 44Lac strains from traditional dairy products on cancer cell lines.

    Science.gov (United States)

    Haghshenas, Babak; Abdullah, Norhafizah; Nami, Yousef; Radiah, Dayang; Rosli, Rozita; Khosroushahi, Ahmad Yari

    2014-12-01

    Lactobacillus and Lactococcus strains isolated from food products can be introduced as probiotics because of their health-promoting characteristics and non-pathogenic nature. This study aims to perform the isolation, molecular identification, and probiotic characterization of Lactobacillus and Lactococcus strains from traditional Iranian dairy products. Primary probiotic assessments indicated high tolerance to low pH and high bile salt conditions, high anti-pathogenic activities, and susceptibility to high consumption antibiotics, thus proving that both strains possess probiotic potential. Cytotoxicity assessments were used to analyze the effects of the secreted metabolite on different cancer cell lines, including HT29, AGS, MCF-7, and HeLa, as well as a normal human cell line (HUVEC). Results showed acceptable cytotoxic properties for secreted metabolites (40 μg/ml dry weight) of Lactococcus lactis subsp. Lactis 44Lac. Such performance was similar to that of Taxol against all of the treated cancer cell lines; however, the strain exhibited no toxicity on the normal cell line. Cytotoxic assessments through flow cytometry and fluorescent microscopy demonstrated that apoptosis is the main cytotoxic mechanism for secreted metabolites of L. lactis subsp. Lactis 44Lac. By contrast, the effects of protease-treated metabolites on the AGS cell line verified the protein nature of anti-cancer metabolites. However, precise characterizations and in vitro/in vivo investigations on purified proteins should be conducted before these metabolites are introduced as potential anti-cancer therapeutics. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Versatile Cas9-Driven Subpopulation Selection Toolbox for Lactococcus lactis.

    Science.gov (United States)

    van der Els, Simon; James, Jennelle K; Kleerebezem, Michiel; Bron, Peter A

    2018-04-15

    CRISPR-Cas9 technology has been exploited for the removal or replacement of genetic elements in a wide range of prokaryotes and eukaryotes. Here, we describe the extension of the Cas9 application toolbox to the industrially important dairy species Lactococcus lactis The Cas9 expression vector pLABTarget, encoding the Streptocccus pyogenes Cas9 under the control of a constitutive promoter, was constructed, allowing plug and play introduction of short guide RNA (sgRNA) sequences to target specific genetic loci. Introduction of a pepN -targeting derivative of pLABTarget into L. lactis strain MG1363 led to a strong reduction in the number of transformants obtained, which did not occur in a pepN deletion derivative of the same strain, demonstrating the specificity and lethality of the Cas9-mediated double-strand breaks in the lactococcal chromosome. Moreover, the same pLABTarget derivative allowed the selection of a pepN deletion subpopulation from its corresponding single-crossover plasmid integrant precursor, accelerating the construction and selection of gene-specific deletion derivatives in L. lactis Finally, pLABTarget, which contained sgRNAs designed to target mobile genetic elements, allowed the effective curing of plasmids, prophages, and integrative conjugative elements (ICEs). These results establish that pLABTarget enables the effective exploitation of Cas9 targeting in L. lactis , while the broad-host-range vector used suggests that this toolbox could readily be expanded to other Gram-positive bacteria. IMPORTANCE Mobile genetic elements in Lactococcus lactis and other lactic acid bacteria (LAB) play an important role in dairy fermentation, having both positive and detrimental effects during the production of fermented dairy products. The pLABTarget vector offers an efficient cloning platform for Cas9 application in lactic acid bacteria. Targeting Cas9 toward mobile genetic elements enabled their effective curing, which is of particular interest in the

  17. Functional characterization of DnSIZ1, a SIZ/PIAS-type SUMO E3 ligase from Dendrobium.

    Science.gov (United States)

    Liu, Feng; Wang, Xiao; Su, Mengying; Yu, Mengyuan; Zhang, Shengchun; Lai, Jianbin; Yang, Chengwei; Wang, Yaqin

    2015-09-17

    SUMOylation is an important post-translational modification of eukaryotic proteins that involves the reversible conjugation of a small ubiquitin-related modifier (SUMO) polypeptide to its specific protein substrates, thereby regulating numerous complex cellular processes. The PIAS (protein inhibitor of activated signal transducers and activators of transcription [STAT]) and SIZ (scaffold attachment factor A/B/acinus/PIAS [SAP] and MIZ) proteins are SUMO E3 ligases that modulate SUMO conjugation. The characteristic features and SUMOylation mechanisms of SIZ1 protein in monocotyledon are poorly understood. Here, we examined the functions of a homolog of Arabidopsis SIZ1, a functional SIZ/PIAS-type SUMO E3 ligase from Dendrobium. In Dendrobium, the predicted DnSIZ1 protein has domains that are highly conserved among SIZ/PIAS-type proteins. DnSIZ1 is widely expressed in Dendrobium organs and has a up-regulated trend by treatment with cold, high temperature and wounding. The DnSIZ1 protein localizes to the nucleus and shows SUMO E3 ligase activity when expressed in an Escherichia coli reconstitution system. Moreover, ectopic expression of DnSIZ1 in the Arabidopsis siz1-2 mutant partially complements several phenotypes and results in enhanced levels of SUMO conjugates in plants exposed to heat shock conditions. We observed that DnSIZ1 acts as a negative regulator of flowering transition which may be via a vernalization-induced pathway. In addition, ABA-hypersensitivity of siz1-2 seed germination can be partially suppressed by DnSIZ1. Our results suggest that DnSIZ1 is a functional homolog of the Arabidopsis SIZ1 with SUMO E3 ligase activity and may play an important role in the regulation of Dendrobium stress responses, flowering and development.

  18. Genes but not genomes reveal bacterial domestication of Lactococcus lactis.

    Directory of Open Access Journals (Sweden)

    Delphine Passerini

    Full Text Available BACKGROUND: The population structure and diversity of Lactococcus lactis subsp. lactis, a major industrial bacterium involved in milk fermentation, was determined at both gene and genome level. Seventy-six lactococcal isolates of various origins were studied by different genotyping methods and thirty-six strains displaying unique macrorestriction fingerprints were analyzed by a new multilocus sequence typing (MLST scheme. This gene-based analysis was compared to genomic characteristics determined by pulsed-field gel electrophoresis (PFGE. METHODOLOGY/PRINCIPAL FINDINGS: The MLST analysis revealed that L. lactis subsp. lactis is essentially clonal with infrequent intra- and intergenic recombination; also, despite its taxonomical classification as a subspecies, it displays a genetic diversity as substantial as that within several other bacterial species. Genome-based analysis revealed a genome size variability of 20%, a value typical of bacteria inhabiting different ecological niches, and that suggests a large pan-genome for this subspecies. However, the genomic characteristics (macrorestriction pattern, genome or chromosome size, plasmid content did not correlate to the MLST-based phylogeny, with strains from the same sequence type (ST differing by up to 230 kb in genome size. CONCLUSION/SIGNIFICANCE: The gene-based phylogeny was not fully consistent with the traditional classification into dairy and non-dairy strains but supported a new classification based on ecological separation between "environmental" strains, the main contributors to the genetic diversity within the subspecies, and "domesticated" strains, subject to recent genetic bottlenecks. Comparison between gene- and genome-based analyses revealed little relationship between core and dispensable genome phylogenies, indicating that clonal diversification and phenotypic variability of the "domesticated" strains essentially arose through substantial genomic flux within the dispensable

  19. Physiochemical parameters optimization for enhanced nisin production by Lactococcus lactis (MTCC 440

    Directory of Open Access Journals (Sweden)

    Puspadhwaja Mall

    2010-02-01

    Full Text Available The influence of various physiochemical parameters on the growth of Lactococcus lactis sub sp. lactis MTCC 440 was studied at shake flask level for 20 h. Media optimization (MRS broth was studied to achieve enhanced growth of the organism and also nisin production. Bioassay of nisin was done with agar diffusion method using Streptococcus agalactae NCIM 2401 as indicator strain. MRS broth (6%, w/v with 0.15μg/ml of nisin supplemented with 0.5% (v/v skimmed milk was found to be the best for nisin production as well as for growth of L lactis. The production of nisin was strongly influenced by the presence of skimmed milk and nisin in MRS broth. The production of nisin was affected by the physical parameters and maximum nisin production was at 30(0C while the optimal temperature for biomass production was 37(0C.

  20. Proton Motive Force-Driven and ATP-Dependent Drug Extrusion Systems in Multidrug-Resistant Lactococcus lactis

    NARCIS (Netherlands)

    BOLHUIS, H; MOLENAAR, D; POELARENDS, G; VANVEEN, HW; POOLMAN, B; DRIESSEN, AJM; KONINGS, WN

    1994-01-01

    Three mutants of Lactococcus lactis subsp. lactis MG1363, termed Eth(R), Dau(R), and Rho(R), were selected for resistance to high concentrations of ethidium bromide, daunomycin, and rhodamine 6G, respectively. These mutants were found to be cross resistant to a number of structurally and

  1. Ventriculoperitoneal shunt infection caused by Bifidobacterium breve.

    Science.gov (United States)

    Suwantarat, Nuntra; Romagnoli, Mark; Wakefield, Teresa; Carroll, Karen C

    2014-08-01

    Bifidobacterium breve is a rare cause of human infections. Previously, bacteremia and meningitis caused by this organism linked to probiotic use have been reported in a neonate. We report the first case of a ventriculoperitoneal shunt infection caused by B. breve in an adult without a history of probiotic use. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. The transcriptional and gene regulatory network of Lactococcus lactis MG1363 during growth in milk.

    Directory of Open Access Journals (Sweden)

    Anne de Jong

    Full Text Available In the present study we examine the changes in the expression of genes of Lactococcus lactis subspecies cremoris MG1363 during growth in milk. To reveal which specific classes of genes (pathways, operons, regulons, COGs are important, we performed a transcriptome time series experiment. Global analysis of gene expression over time showed that L. lactis adapted quickly to the environmental changes. Using upstream sequences of genes with correlated gene expression profiles, we uncovered a substantial number of putative DNA binding motifs that may be relevant for L. lactis fermentative growth in milk. All available novel and literature-derived data were integrated into network reconstruction building blocks, which were used to reconstruct and visualize the L. lactis gene regulatory network. This network enables easy mining in the chrono-transcriptomics data. A freely available website at http://milkts.molgenrug.nl gives full access to all transcriptome data, to the reconstructed network and to the individual network building blocks.

  3. The effect of fermented milk with Bifidobacterium infantis on ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-11-19

    Nov 19, 2008 ... In recent years, Bifidobacteria have attracted considerable attention due to their overall ... EPEC, the colonies were violet in colour with a metallic lustre on. EMB medium). ...... A new selective medium for. Bifidobacterium spp.

  4. Cholic acid resistance and the adherence ability of Bifidobacterium ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-05

    Oct 5, 2009 ... 1Faculty of Food Science and Technology, University Putra Malaysia, 43400, .... The adherence of Bifidobacterium strains on HT-29 cell culture was .... Thomas LA, Veysey MJ, French G, Hylemon, PB, Murphy GM, Dowling.

  5. Taxonomy, physiology and growth of Lactococcus lactis: a review

    Directory of Open Access Journals (Sweden)

    Dubravka Samaržija

    2001-01-01

    Full Text Available Lactococcus lactis species is one of the most important groups of lactic acid bacteria that are used in the dairy industry. The major functions of this species in dairy fermentation are the production of lactic acid from lactose, hydrolysis of casein and citric acid fermentation. Thus their metabolic end products and enzymes directly or indirectly have significant influence in determining the texture and flavour of the final products. In recent years, genetics and physiological properties of lactococci have considerable changed. Therefore, both for basic research and for application purposes in this paper the general view of the new taxonomic classification of Lactococcus lactis, the role of their plasmids and the physiology and nutritional requirements during growth are discussed.

  6. Use of murine models to detect the allergenicity of genetically modified Lactococcus lactis NZ9000/pNZPNK.

    Science.gov (United States)

    Chiang, Shen-Shih; Liu, Chin-Feng; Ku, Ting-Wei; Mau, Jeng-Leun; Lin, Hsin-Tang; Pan, Tzu-Ming

    2011-04-27

    By introducing aprN into Lactococcus lactis NZ9000, the genetically modified L. lactis NZ9000/pNZPNK successfully expressed the nattokinase. The safety assessment of this novel strain was based on allergenicity of pepsin digestion stability and murine model serologic identity. Subjecting to the GM strain and host to pepsin digestion, the soluble fractions and cell debris were fast degraded completely. Feeding with ovalbumin resulted in significantly higher production of IgG1 and IgE as compared to that of L. lactis NZ9000/pNZPNK or L. lactis NZ9000. Further, the serum IgG2a level increased dose-dependently at week 2 and induced immune reaction toward Th1 pathway. Secretion of cytokines IL-4 and IL-10 fed with lactococci was significantly lower than that of the OVA group. L. lactis NZ9000/pNZPNK did not increase the proliferation of type 2 helper T cells in spleen or induce allergenicity in BALB/c mice. On the basis of the results, the new GM lactic acid bacterium is regarded as safe to use.

  7. Autolysis of Lactococcus lactis is increased upon D-alanine depletion of peptidoglycan and lipoteichoic acids

    NARCIS (Netherlands)

    Steen, Anton; Palumbo, Emmanuelle; Deghorain, Marie; Cocconcelli, Pier Sandro; Delcour, Jean; Kuipers, Oscar P.; Kok, Jan; Buist, Girbe; Hols, Pascal

    Mutations in the genes encoding enzymes responsible for the incorporation of D-Ala into the cell wall of Lactococcus lactis affect autolysis. An L. lactis alanine racemase (alr) mutant is strictly dependent on an external Supply Of D-Ala to be able to synthesize peptidoglycan and to incorporate

  8. Impact of lactic acid bacteria on conjugated linoleic acid content and atherogenic index of butter

    Directory of Open Access Journals (Sweden)

    L Roufegari-Nejad

    2012-11-01

    Full Text Available This is a study aimed to investigate the effect of lactic acid bacteria including Lactobacillus acidophilus and Sterptococcus thermophilus (as thermophilic culture, Lactococcus lactis subsp. lactis, cremoris and diacetylactis, Leuconostoc citrovorum (as mesophilic culture, Lactobacillus acidophilus, Lactobacillus casei, Bifidobacterium lactis and a mixed culture of L.acidophilus, L. casei and B. lactis on fatty acid profile, conjugated linoleic acid (CLA and atherogenic index (AI of butter. Fatty acid analysis with gas chromatography indicated that application of thermophilic and mixed culture decreased the ratio of saturated to unsaturated fatty acid; whereas, the butters made with L. acidophilus had the highest content of CLA. Moreover, AI in the samples prepared with thermophilic cultures was the least. Sensory evaluation of the treatments revealed no significant differences (p> 0/05 in appearance and color. However, the butters prepared with thermophilic and mesophilic cultures had more desirable taste in comparison with the samples made with L. acidophilus, L. casei and B. lactis. From the nutritional point of view, the adverse effect of butter could be diminished via the application of selected lactic acid bacteria.

  9. Genome‐scale diversity and niche adaptation analysis of Lactococcus lactis by comparative genome hybridization using multi‐strain arrays

    Science.gov (United States)

    Siezen, Roland J.; Bayjanov, Jumamurat R.; Felis, Giovanna E.; van der Sijde, Marijke R.; Starrenburg, Marjo; Molenaar, Douwe; Wels, Michiel; van Hijum, Sacha A. F. T.; van Hylckama Vlieg, Johan E. T.

    2011-01-01

    Summary Lactococcus lactis produces lactic acid and is widely used in the manufacturing of various fermented dairy products. However, the species is also frequently isolated from non‐dairy niches, such as fermented plant material. Recently, these non‐dairy strains have gained increasing interest, as they have been described to possess flavour‐forming activities that are rarely found in dairy isolates and have diverse metabolic properties. We performed an extensive whole‐genome diversity analysis on 39 L. lactis strains, isolated from dairy and plant sources. Comparative genome hybridization analysis with multi‐strain microarrays was used to assess presence or absence of genes and gene clusters in these strains, relative to all L. lactis sequences in public databases, whereby chromosomal and plasmid‐encoded genes were computationally analysed separately. Nearly 3900 chromosomal orthologous groups (chrOGs) were defined on basis of four sequenced chromosomes of L. lactis strains (IL1403, KF147, SK11, MG1363). Of these, 1268 chrOGs are present in at least 35 strains and represent the presently known core genome of L. lactis, and 72 chrOGs appear to be unique for L. lactis. Nearly 600 and 400 chrOGs were found to be specific for either the subspecies lactis or subspecies cremoris respectively. Strain variability was found in presence or absence of gene clusters related to growth on plant substrates, such as genes involved in the consumption of arabinose, xylan, α‐galactosides and galacturonate. Further niche‐specific differences were found in gene clusters for exopolysaccharides biosynthesis, stress response (iron transport, osmotolerance) and bacterial defence mechanisms (nisin biosynthesis). Strain variability of functions encoded on known plasmids included proteolysis, lactose fermentation, citrate uptake, metal ion resistance and exopolysaccharides biosynthesis. The present study supports the view of L. lactis as a species with a very flexible

  10. Characterization of the role of para-aminobenzoic acid biosynthesis in folate production by Lactococcus lactis

    NARCIS (Netherlands)

    Wegkamp, H.B.A.; Oorschot, van A.; Vos, de W.M.; Smid, E.J.

    2007-01-01

    The pab genes for para-aminobenzoic acid (pABA) biosynthesis in Lactococcus lactis were identified and characterized. In L. lactis NZ9000, only two of the three genes needed for pABA production were initially found. No gene coding for 4-amino-4-deoxychorismate lyase (pabC) was initially annotated,

  11. Identification of Bifidobacterium strains from faeces of lambs

    Czech Academy of Sciences Publication Activity Database

    Bunešová, V.; Vlková, E.; Killer, Jiří; Rada, V.; Ročková, Š.

    2012-01-01

    Roč. 105, 1-3 (2012), 355-360 ISSN 0921-4488 R&D Projects: GA ČR GA523/08/1091; GA ČR GD525/08/H060 Institutional support: RVO:67985904 Keywords : bifidobacterium * identification * lambs Subject RIV: GH - Livestock Nutrition Impact factor: 1.124, year: 2012

  12. 33 CFR 173.17 - Reciprocity.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Reciprocity. 173.17 Section 173.17 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY VESSEL NUMBERING AND CASUALTY AND ACCIDENT REPORTING Numbering § 173.17 Reciprocity. (a) Section...

  13. RETRACTED: Association between the ACE I/D gene polymorphism and T2DN susceptibility: The risk of T2DM developing into T2DN in the Asian population.

    Science.gov (United States)

    Zhong, Weiqiang; Jiang, Zongpei; Zhou, Tian-Biao

    2015-12-01

    This article has been included in a multiple retraction: Weiqiang Zhong, Zongpei Jiang, and Tian-Biao Zhou Association between the ACE I/D gene polymorphism and T2DN susceptibility: The risk of T2DM developing into T2DN in the Asian population Journal of Renin-Angiotensin-Aldosterone System 1470320314566019, first published on January 26, 2015 doi: 10.1177/1470320314566019 This article has been retracted at the request of the Editors and the Publisher. After conducting a thorough investigation, SAGE found that the submitting authors of a number of papers published in the Journal of the Renin-Angiotensin Aldosterone System ( JRAAS) (listed below) had supplied fabricated contact details for their nominated reviewers. The Editors accepted these papers based on the reports supplied by the individuals using these fake reviewer email accounts. After concluding that the peer review process was therefore seriously compromised, SAGE and the journal Editors have decided to retract all affected articles. Online First articles (these articles will not be published in an issue) Wenzhuang Tang, Tian-Biao Zhou, and Zongpei Jiang Association of the angiotensinogen M235T gene polymorphism with risk of diabetes mellitus developing into diabetic nephropathy Journal of Renin-Angiotensin-Aldosterone System 1470320314563426, first published on December 18, 2014 doi: 10.1177/1470320314563426 Tian-Biao Zhou, Hong-Yan Li, Zong-Pei Jiang, Jia-Fan Zhou, Miao-Fang Huang, and Zhi-Yang Zhou Role of renin-angiotensin-aldosterone system inhibitors in radiation nephropathy Journal of Renin-Angiotensin-Aldosterone System 1470320314563424, first published on December 18, 2014 doi: 10.1177/1470320314563424 Weiqiang Zhong, Zongpei Jiang, and Tian-Biao Zhou Association between the ACE I/D gene polymorphism and T2DN susceptibility: The risk of T2DM developing into T2DN in the Asian population Journal of Renin-Angiotensin-Aldosterone System 1470320314566019, first published on January 26, 2015 doi: 10

  14. Hypocellularity in the Murine Model for Down Syndrome Ts65Dn Is Not Affected by Adult Neurogenesis

    Science.gov (United States)

    López-Hidalgo, Rosa; Ballestín, Raul; Vega, Jessica; Blasco-Ibáñez, José M.; Crespo, Carlos; Gilabert-Juan, Javier; Nácher, Juan; Varea, Emilio

    2016-01-01

    Down syndrome (DS) is caused by the presence of an extra copy of the chromosome 21 and it is the most common aneuploidy producing intellectual disability. Neural mechanisms underlying this alteration may include defects in the formation of neuronal networks, information processing and brain plasticity. The murine model for DS, Ts65Dn, presents reduced adult neurogenesis. This reduction has been suggested to underlie the hypocellularity of the hippocampus as well as the deficit in olfactory learning in the Ts65Dn mice. Similar alterations have also been observed in individuals with DS. To determine whether the impairment in adult neurogenesis is, in fact, responsible for the hypocellularity in the hippocampus and physiology of the olfactory bulb, we have analyzed cell proliferation and neuronal maturation in the two major adult neurogenic niches in the Ts656Dn mice: the subgranular zone (SGZ) of the hippocampus and the subventricular zone (SVZ). Additionally, we carried out a study to determine the survival rate and phenotypic fate of newly generated cells in both regions, injecting 5′BrdU and sacrificing the mice 21 days later, and analyzing the number and phenotype of the remaining 5′BrdU-positive cells. We observed a reduction in the number of proliferating (Ki67 positive) cells and immature (doublecortin positive) neurons in the subgranular and SVZ of Ts65Dn mice, but we did not observe changes in the number of surviving cells or in their phenotype. These data correlated with a lower number of apoptotic cells (cleaved caspase 3 positive) in Ts65Dn. We conclude that although adult Ts65Dn mice have a lower number of proliferating cells, it is compensated by a lower level of cell death. This higher survival rate in Ts65Dn produces a final number of mature cells similar to controls. Therefore, the reduction of adult neurogenesis cannot be held responsible for the neuronal hypocellularity in the hippocampus or for the olfactory learning deficit of Ts65Dn mice

  15. Deciphering a unique biotin scavenging pathway with redundant genes in the probiotic bacterium Lactococcus lactis.

    Science.gov (United States)

    Zhang, Huimin; Wang, Qingjing; Fisher, Derek J; Cai, Mingzhu; Chakravartty, Vandana; Ye, Huiyan; Li, Ping; Solbiati, Jose O; Feng, Youjun

    2016-05-10

    Biotin protein ligase (BPL) is widespread in the three domains of the life. The paradigm BPL is the Escherichia coli BirA protein, which also functions as a repressor for the biotin biosynthesis pathway. Here we report that Lactococcus lactis possesses two different orthologues of birA (birA1_LL and birA2_LL). Unlike the scenario in E. coli, L. lactis appears to be auxotrophic for biotin in that it lacks a full biotin biosynthesis pathway. In contrast, it retains two biotin transporter-encoding genes (bioY1_LL and bioY2_LL), suggesting the use of a scavenging strategy to obtain biotin from the environment. The in vivo function of the two L. lactis birA genes was judged by their abilities to complement the conditional lethal E. coli birA mutant. Thin-layer chromatography and mass spectroscopy assays demonstrated that these two recombinant BirA proteins catalyze the biotinylation reaction of the acceptor biotin carboxyl carrier protein (BCCP), through the expected biotinoyl-AMP intermediate. Gel shift assays were used to characterize bioY1_LL and BirA1_LL. We also determined the ability to uptake (3)H-biotin by L. lactis. Taken together, our results deciphered a unique biotin scavenging pathway with redundant genes present in the probiotic bacterium L. lactis.

  16. Immune effects of the probiotic Bifidobacterium breve

    OpenAIRE

    Ezendam J; Loveren H van; TOX

    2007-01-01

    Bifidobacterium breve, een probiotische bacterie, heeft gunstige effecten op zowel allergieen als autoimmuniteit - een afweerreactie op lichaamseigen bestanddelen - bij proefdieren. Probiotica worden in reclameboodschappen ook wel 'goede bacterien' genoemd. Fabrikanten claimen een positief effect van probiotica op darmflora, weerstand en preventie van allergieen. De meeste van deze effecten zijn echter niet wetenschappelijk onderbouwd. Het is bekend dat de effecten van probiotica afhangen van...

  17. Early-Onset Diabetic E1-DN Mice Develop Albuminuria and Glomerular Injury Typical of Diabetic Nephropathy

    Directory of Open Access Journals (Sweden)

    Mervi E. Hyvönen

    2015-01-01

    Full Text Available The transgenic E1-DN mice express a kinase-negative epidermal growth factor receptor in their pancreatic islets and are diabetic from two weeks of age due to impaired postnatal growth of β-cell mass. Here, we characterize the development of hyperglycaemia-induced renal injury in the E1-DN mice. Homozygous mice showed increased albumin excretion rate (AER at the age of 10 weeks; the albuminuria increased over time and correlated with blood glucose. Morphometric analysis of PAS-stained histological sections and electron microscopy images revealed mesangial expansion in homozygous E1-DN mice, and glomerular sclerosis was observed in the most hyperglycaemic mice. The albuminuric homozygous mice developed also other structural changes in the glomeruli, including thickening of the glomerular basement membrane and widening of podocyte foot processes that are typical for diabetic nephropathy. Increased apoptosis of podocytes was identified as one mechanism contributing to glomerular injury. In addition, nephrin expression was reduced in the podocytes of albuminuric homozygous E1-DN mice. Tubular changes included altered epithelial cell morphology and increased proliferation. In conclusion, hyperglycaemic E1-DN mice develop albuminuria and glomerular and tubular injury typical of human diabetic nephropathy and can serve as a new model to study the mechanisms leading to the development of diabetic nephropathy.

  18. An engineered Lactococcus lactis strain exerts significant immune responses through efficient expression and delivery of Helicobacter pylori Lpp20 antigen.

    Science.gov (United States)

    Zhang, Rongguang; Peng, Xiaoyan; Duan, Guangcai; Shi, Qingfeng; Chen, Shuaiyin; Wang, Chen; Fan, Qingtang; Xi, Yuanlin

    2016-12-01

    To produce and deliver Helicobacter pylori lipoprotein Lpp20 via using Lactococcus lactis with aim of developing an efficient way to use this protective antigen in vaccine formulation. An engineered L. lactis strain carrying the lpp20 gene from H. pylori was constructed. The inducible expression of Lpp20 in L. lactis was detected as a 20 kDa intracellular protein by SDS-PAGE. Lpp20 constituted 10 % of the L. lactis cellular proteins. The expression product was highly immunoreactive, as demonstrated by western blot assays using mouse anti-H. pylori sera. Animal experimentation showed that oral vaccination with the engineered strain excited significantly elevated levels of serum Lpp20-specific IgG antibodies in BALB/c mice (P lactis, demonstrating an efficient utilization mode of Lpp20 in anti-H. pylori vaccination.

  19. 21 CFR 173.290 - Trichloroethylene.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Trichloroethylene. 173.290 Section 173.290 Food and..., Lubricants, Release Agents and Related Substances § 173.290 Trichloroethylene. Tolerances are established for residues of trichloroethylene resulting from its use as a solvent in the manufacture of foods as follows...

  20. 19 CFR 173.0 - Scope.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Scope. 173.0 Section 173.0 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) ADMINISTRATIVE REVIEW IN GENERAL § 173.0 Scope. This part deals with the general authority of review, the...

  1. Safety Evaluations of Bifidobacterium bifidum BGN4 and Bifidobacterium longum BORI

    Directory of Open Access Journals (Sweden)

    Min Jeong Kim

    2018-05-01

    Full Text Available Over the past decade, a variety of lactic acid bacteria have been commercially available to and steadily used by consumers. However, recent studies have shown that some lactic acid bacteria produce toxic substances and display properties of virulence. To establish safety guidelines for lactic acid bacteria, the Food and Agriculture Organization of the United Nations (FAO/World Health Organization (WHO has suggested that lactic acid bacteria be characterized and proven safe for consumers’ health via multiple experiments (e.g., antibiotic resistance, metabolic activity, toxin production, hemolytic activity, infectivity in immune-compromised animal species, human side effects, and adverse-outcome analyses. Among the lactic acid bacteria, Bifidobacterium and Lactobacillus species are probiotic strains that are most commonly commercially produced and actively studied. Bifidobacterium bifidum BGN4 and Bifidobacterium longum BORI have been used in global functional food markets (e.g., China, Germany, Jordan, Korea, Lithuania, New Zealand, Poland, Singapore, Thailand, Turkey, and Vietnam as nutraceutical ingredients for decades, without any adverse events. However, given that the safety of some newly screened probiotic species has recently been debated, it is crucial that the consumer safety of each commercially utilized strain be confirmed. Accordingly, this paper details a safety assessment of B. bifidum BGN4 and B. longum BORI via the assessment of ammonia production, hemolysis of blood cells, biogenic amine production, antimicrobial susceptibility pattern, antibiotic resistance gene transferability, PCR data on antibiotic resistance genes, mucin degradation, genome stability, and possession of virulence factors. These probiotic strains showed neither hemolytic activity nor mucin degradation activity, and they did not produce ammonia or biogenic amines (i.e., cadaverine, histamine or tyramine. B. bifidum BGN4 and B. longum BORI produced a small

  2. Quasirecognition by prime graph of finite simple groups ${}^2D_n(3$

    Directory of Open Access Journals (Sweden)

    Behrooz Khosravi

    2014-12-01

    Full Text Available Let $G$ be a finite group. In [Ghasemabadi et al., characterizations of the simple group ${}^2D_n(3$ by prime graph and spectrum, Monatsh Math., 2011] it is proved that if $n$ is odd, then ${}^2D _n(3$ is recognizable by prime graph and also by element orders. In this paper we prove that if $n$ is even, then $D={}^2D_{n}(3$ is quasirecognizable by prime graph, i.e. every finite group $G$ with $Gamma(G=Gamma(D$ has a unique nonabelian composition factor and this factor is isomorphic to $D$.

  3. Secretion and properties of a hybrid Kluyveromyces lactis-Aspergillus niger β-galactosidase

    Directory of Open Access Journals (Sweden)

    Becerra Manuel

    2006-12-01

    Full Text Available Abstract Background The β-galactosidase from Kluyveromyces lactis is a protein of outstanding biotechnological interest in the food industry and milk whey reutilization. However, due to its intracellular nature, its industrial production is limited by the high cost associated to extraction and downstream processing. The yeast-system is an attractive method for producing many heterologous proteins. The addition of a secretory signal in the recombinant protein is the method of choice to sort it out of the cell, although biotechnological success is not guaranteed. The cell wall acting as a molecular sieve to large molecules, culture conditions and structural determinants present in the protein, all have a decisive role in the overall process. Protein engineering, combining domains of related proteins, is an alternative to take into account when the task is difficult. In this work, we have constructed and analyzed two hybrid proteins from the β-galactosidase of K. lactis, intracellular, and its Aspergillus niger homologue that is extracellular. In both, a heterologous signal peptide for secretion was also included at the N-terminus of the recombinant proteins. One of the hybrid proteins obtained has interesting properties for its biotechnological utilization. Results The highest levels of intracellular and extracellular β-galactosidase were obtained when the segment corresponding to the five domain of K. lactis β-galactosidase was replaced by the corresponding five domain of the A. niger β-galactosidase. Taking into account that this replacement may affect other parameters related to the activity or the stability of the hybrid protein, a thoroughly study was performed. Both pH (6.5 and temperature (40°C for optimum activity differ from values obtained with the native proteins. The stability was higher than the corresponding to the β-galactosidase of K. lactis and, unlike this, the activity of the hybrid protein was increased by the presence

  4. 22 CFR 17.3 - Fault.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Fault. 17.3 Section 17.3 Foreign Relations...) § 17.3 Fault. A recipient of an overpayment is without fault if he or she performed no act of... agency may have been at fault in initiating an overpayment will not necessarily relieve the individual...

  5. Mupirocin-mucin agar for selective enumeration of Bifidobacterium bifidum

    Czech Academy of Sciences Publication Activity Database

    Pechar, R.; Rada, V.; Parafati, L.; Musilová, S.; Bunešová, V.; Vlková, E.; Killer, Jiří; Mrázek, Jakub; Kmeť, V.; Svejštil, R.

    2014-01-01

    Roč. 191, č. 1 (2014), s. 32-35 ISSN 0168-1605 R&D Projects: GA ČR GA13-08803S Institutional support: RVO:67985904 Keywords : probiotics * Bifidobacterium bifidum * selective enumeration Subject RIV: EE - Microbiology, Virology Impact factor: 3.082, year: 2014

  6. A comparative study between inhibitory effect of L. lactis and nisin on important pathogenic bacteria in Iranian UF Feta cheese

    Directory of Open Access Journals (Sweden)

    Saeed Mirdamadi

    2015-02-01

    Full Text Available   Introduction : In the present study, the inhibitory effect of nisin-producing Lactococcus lactis during co-culture and pure standard nisin were assessed against selected foodborne pathogenes in growth medium and Iranian UF Feta cheese. In comparison L lactis, not only proves flavor but also plays a better role in microbial quality of Iranian UF Feta cheese as a model of fermented dairy products.   Materials and method s: L. lactis subsp. lactis as nisin producer strain, Listeria monocytogenes, Escherichia coli and Staphylococcus aureus as pathogenic strains were inoculated in Ultra-Filtered Feta cheese. Growth curve of bacterial strains were studied by colony count method in growth medium and UF Feta cheese separately and during co-culture with L. lactis. Nisin production was determined by agar diffusion assay method against susceptible test strain and confirmed by RP-HPLC analysis method.   Results : Counts of L. monocytogenes decreased in cheese sample containing L. lactis and standard nisin, to 103 CFU/g after 7 days and it reached to undetectable level within 2 weeks. S. aureus counts remained at its initial number, 105 CFU/g, after 7 days then decreased to 104 CFU/g on day 14 and it was not detectable on day 28. E. coli numbers increased in both treatments after 7 days and then decreased to 104 CFU/g after 28 days. Despite the increasing number of E. coli in growth medium containing nisin, due to the synergistic effect of nisin and other metabolites produced by Lactococcus lactis and starter cultures, the number of E. coli decreased with slow rate . Discussion and conclusion : The results showed, L. monocytogenes was inhibited by L. lactis before entering the logarithmic phase during co-culture. S. aureus was also inhibited during co-culture, but it showed less sensitivity in comparison with L. monocytogenes. However, the number of E. coli remained steady in co-culture with L. lactis. Also, we found that, in all cheese samples, E

  7. 21 CFR 173.210 - Acetone.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acetone. 173.210 Section 173.210 Food and Drugs..., Lubricants, Release Agents and Related Substances § 173.210 Acetone. A tolerance of 30 parts per million is established for acetone in spice oleoresins when present therein as a residue from the extraction of spice. ...

  8. Is Bifidobacterium breve effective in the treatment of childhood constipation? Results from a pilot study.

    Science.gov (United States)

    Tabbers, M M; de Milliano, I; Roseboom, M G; Benninga, M A

    2011-02-23

    Probiotics are increasingly used in the treatment of functional gastrointestinal disorders. Studies in constipated adults with a Bifidus yoghurt (containing Bifidobacterium breve, Bifidobacterium bifidum and Lactobacillus acidophilus) showed a significant increase in defecation frequency. The aim of this pilot study was to determine if Bifidobacterium breve is effective in the treatment of childhood constipation. Children, 3 to 16 years of age, with functional constipation according to the Rome III criteria were eligible for this study. During 4 weeks, children received one sachet of powder daily, containing 108- 1010 CFU Bifidobacterium breve. Furthermore, children were instructed to try to defecate on the toilet for 5-10 minutes after each meal and to complete a standardized bowel diary daily. The primary outcome measure was change in defecation frequency. Secondary outcome measures were stool consistency using the Bristol stool scale frequency of episodes of faecal incontinence, pain during defecation, frequency of abdominal pain, frequency of adverse effects (nausea, diarrhoea and bad taste), and frequency of intake of bisacodyl. Twenty children (75% male, mean age 7.4) were included in this pilot study. The defecation frequency per week significantly increased from 0.9 (0-2) at baseline to 4.9 (0-21) in week 4 (p Bifidobacterium breve is effective in increasing stool frequency in children with functional constipation. Furthermore it has a positive effect with respect to stool consistency, decreasing the number of faecal incontinence episodes and in diminishing abdominal pain. A randomized placebo controlled trial is required to confirm these data.

  9. Is Bifidobacterium breve effective in the treatment of childhood constipation? Results from a pilot study

    Directory of Open Access Journals (Sweden)

    Roseboom MG

    2011-02-01

    Full Text Available Abstract Background Probiotics are increasingly used in the treatment of functional gastrointestinal disorders. Studies in constipated adults with a Bifidus yoghurt (containing Bifidobacterium breve, Bifidobacterium bifidum and Lactobacillus acidophilus showed a significant increase in defecation frequency. The aim of this pilot study was to determine if Bifidobacterium breve is effective in the treatment of childhood constipation. Methods Children, 3 to 16 years of age, with functional constipation according to the Rome III criteria were eligible for this study. During 4 weeks, children received one sachet of powder daily, containing 108- 1010 CFU Bifidobacterium breve. Furthermore, children were instructed to try to defecate on the toilet for 5-10 minutes after each meal and to complete a standardized bowel diary daily. The primary outcome measure was change in defecation frequency. Secondary outcome measures were stool consistency using the Bristol stool scale frequency of episodes of faecal incontinence, pain during defecation, frequency of abdominal pain, frequency of adverse effects (nausea, diarrhoea and bad taste, and frequency of intake of bisacodyl. Results Twenty children (75% male, mean age 7.4 were included in this pilot study. The defecation frequency per week significantly increased from 0.9 (0-2 at baseline to 4.9 (0-21 in week 4 (p Conclusion Bifidobacterium breve is effective in increasing stool frequency in children with functional constipation. Furthermore it has a positive effect with respect to stool consistency, decreasing the number of faecal incontinence episodes and in diminishing abdominal pain. A randomized placebo controlled trial is required to confirm these data.

  10. Lactobacillus delbrueckii ssp. lactis and ssp. bulgaricus: a chronicle of evolution in action.

    Science.gov (United States)

    El Kafsi, Hela; Binesse, Johan; Loux, Valentin; Buratti, Julien; Boudebbouze, Samira; Dervyn, Rozenn; Kennedy, Sean; Galleron, Nathalie; Quinquis, Benoît; Batto, Jean-Michel; Moumen, Bouziane; Maguin, Emmanuelle; van de Guchte, Maarten

    2014-05-28

    Lactobacillus delbrueckii ssp. lactis and ssp. bulgaricus are lactic acid producing bacteria that are largely used in dairy industries, notably in cheese-making and yogurt production. An earlier in-depth study of the first completely sequenced ssp. bulgaricus genome revealed the characteristics of a genome in an active phase of rapid evolution, in what appears to be an adaptation to the milk environment. Here we examine for the first time if the same conclusions apply to the ssp. lactis, and discuss intra- and inter-subspecies genomic diversity in the context of evolutionary adaptation. Both L. delbrueckii ssp. show the signs of reductive evolution through the elimination of superfluous genes, thereby limiting their carbohydrate metabolic capacities and amino acid biosynthesis potential. In the ssp. lactis this reductive evolution has gone less far than in the ssp. bulgaricus. Consequently, the ssp. lactis retained more extended carbohydrate metabolizing capabilities than the ssp. bulgaricus but, due to high intra-subspecies diversity, very few carbohydrate substrates, if any, allow a reliable distinction of the two ssp. We further show that one of the most important traits, lactose fermentation, of one of the economically most important dairy bacteria, L. delbruecki ssp. bulgaricus, relies on horizontally acquired rather than deep ancestral genes. In this sense this bacterium may thus be regarded as a natural GMO avant la lettre. The dairy lactic acid producing bacteria L. delbrueckii ssp. lactis and ssp. bulgaricus appear to represent different points on the same evolutionary track of adaptation to the milk environment through the loss of superfluous functions and the acquisition of functions that allow an optimized utilization of milk resources, where the ssp. bulgaricus has progressed further away from the common ancestor.

  11. Recombinant invasive Lactococcus lactis can transfer DNA vaccines either directly to dendritic cells or across an epithelial cell monolayer.

    Science.gov (United States)

    de Azevedo, Marcela; Meijerink, Marjolein; Taverne, Nico; Pereira, Vanessa Bastos; LeBlanc, Jean Guy; Azevedo, Vasco; Miyoshi, Anderson; Langella, Philippe; Wells, Jerry M; Chatel, Jean-Marc

    2015-09-11

    Lactococcus lactis (L. lactis), a generally regarded as safe (GRAS) bacterium has recently been investigated as a mucosal delivery vehicle for DNA vaccines. Because of its GRAS status, L. lactis represents an attractive alternative to attenuated pathogens. Previous studies showed that eukaryotic expression plasmids could be delivered into intestinal epithelial cells (IECs) by L. lactis, or recombinant invasive strains of L. lactis, leading to heterologous protein expression. Although expression of antigens in IECs might lead to vaccine responses, it would be of interest to know whether uptake of L. lactis DNA vaccines by dendritic cells (DCs) could lead to antigen expression as they are unique in their ability to induce antigen-specific T cell responses. To test this, we incubated mouse bone marrow-derived DCs (BMDCs) with invasive L. lactis strains expressing either Staphylococcus aureus Fibronectin Binding Protein A (LL-FnBPA+), or Listeria monocytogenes mutated Internalin A (LL-mInlA+), both strains carrying a plasmid DNA vaccine (pValac) encoding for the cow milk allergen β-lactoglobulin (BLG). We demonstrated that they can transfect BMDCs, inducing the secretion of the pro-inflammatory cytokine IL-12. We also measured the capacity of strains to invade a polarized monolayer of IECs, mimicking the situation encountered in the gastrointestinal tract. Gentamycin survival assay in these cells showed that LL-mInlA+ is 100 times more invasive than L. lactis. The cross-talk between differentiated IECs, BMDCs and bacteria was also evaluated using an in vitro transwell co-culture model. Co-incubation of strains in this model showed that DCs incubated with LL-mInlA+ containing pValac:BLG could express significant levels of BLG. These results suggest that DCs could sample bacteria containing the DNA vaccine across the epithelial barrier and express the antigen. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. Genetically engineered Lactococcus lactis protect against house dust mite allergy in a BALB/c mouse model.

    Directory of Open Access Journals (Sweden)

    Chunqing Ai

    Full Text Available Mucosal vaccine based on lactic acid bacteria is an attractive concept for the prevention and treatment of allergic diseases, but their mechanisms of action in vivo are poorly understood. Therefore, we sought to investigate how recombinant major dust mite allergen Der p2-expressing Lactococcus lactis as a mucosal vaccine induced the immune tolerance against house dust mite allergy in a mouse model.Three strains of recombinant L. lactis producing Der p2 in different cell components (extracellular, intracellular and cell wall were firstly constructed. Their prophylactic potential was evaluated in a Der p2-sensitised mouse model, and immunomodulation properties at the cellular level were determined by measuring cytokine production in vitro.Der p2 expressed in the different recombinant L. lactis strains was recognized by a polyclonal anti-Der p2 antibody. Oral treatment with the recombinant L. lactis prior sensitization significantly prevented the development of airway inflammation in the Der p2-sensitized mice, as determined by the attenuation of inflammatory cells infiltration in the lung tissues and decrease of Th2 cytokines IL-4 and IL-5 levels in bronchoalveolar lavage. In addition, the serum allergen-specific IgE levels were significantly reduced, and the levels of IL-4 in the spleen and mesenteric lymph nodes cell cultures were also markedly decreased upon allergen stimulation in the mice fed with the recombinant L. lactis strains. These protective effects correlated with a significant up-regulation of regulatory T cells in the mesenteric lymph nodes.Oral pretreatment with live recombinant L. lactis prevented the development of allergen-induced airway inflammation primarily by the induction of specific mucosal immune tolerance.

  13. Heterologous expression of Streptococcus mutans Cnm in Lactococcus lactis promotes intracellular invasion, adhesion to human cardiac tissues and virulence.

    Science.gov (United States)

    Freires, Irlan A; Avilés-Reyes, Alejandro; Kitten, Todd; Simpson-Haidaris, P J; Swartz, Michael; Knight, Peter A; Rosalen, Pedro L; Lemos, José A; Abranches, Jacqueline

    2017-01-02

    In S. mutans, the expression of the surface glycoprotein Cnm mediates binding to extracellular matrix proteins, endothelial cell invasion and virulence in the Galleria mellonella invertebrate model. To further characterize Cnm as a virulence factor, the cnm gene from S. mutans strain OMZ175 was expressed in the non-pathogenic Lactococcus lactis NZ9800 using a nisin-inducible system. Despite the absence of the machinery necessary for Cnm glycosylation, Western blot and immunofluorescence microscopy analyses demonstrated that Cnm was effectively expressed and translocated to the cell wall of L. lactis. Similar to S. mutans, expression of Cnm in L. lactis enabled robust binding to collagen and laminin, invasion of human coronary artery endothelial cells and increased virulence in G. mellonella. Using an ex vivo human heart tissue colonization model, we showed that Cnm-positive strains of either S. mutans or L. lactis outcompete their Cnm-negative counterparts for tissue colonization. Finally, Cnm expression facilitated L. lactis adhesion and colonization in a rabbit model of infective endocarditis. Collectively, our results provide unequivocal evidence that binding to extracellular matrices mediated by Cnm is an important virulence attribute of S. mutans and confirm the usefulness of the L. lactis heterologous system for further characterization of bacterial virulence factors.

  14. Proposal for creation of a new genus Neomicrococcus gen. nov. to accommodate Zhihengliuella aestuarii Baik et al. 2011 and Micrococcus lactis Chittpurna et al. 2011 as Neomicrococcus aestuarii comb. nov. and Neomicrococcus lactis comb. nov.

    Science.gov (United States)

    Prakash, Om; Sharma, Avinash; Nimonkar, Yogesh; Shouche, Yogesh S

    2015-11-01

    Micrococcus lactis and Zhihengliuella aestuarii were described independently in 2011. Their type strains showed high levels of 16S rRNA gene sequence similarity (99.3%). Phylogenetic analysis revealed that M. lactis MCC 2278T and Z. aestuarii JCM 16166T formed a monophyletic group and showed distant relationships to other members of closely related genera such as Micrococcus, Zhihengliuella, Arthrobacter and Citricoccus. The presence of large proportions of iso-C14:0 and iso-C16:0 with small amounts of iso-C15:0 distinguished M. lactis MCC 2278T and Z. aestuarii JCM 16166T from other members of the genera Micrococcus and Zhihengliuella. Unlike other members of the genera Zhihengliuella and Micrococcus, M. lactis MCC 2278T and Z. aestuarii JCM 16166T showed growth at low concentrations of NaCl. Thus, based on distinctive phylogenetic, chemotaxonomic and physiological features of these two organisms in comparison with other members of the genera Micrococcus and Zhihengliuella, it is clear that they do not fit within the existing classification and deserve separate status. DNA-DNA hybridization between the two type strains was 63%, indicating that they represent separate species. In this study, we propose the creation of a novel genus, Neomicrococcus gen. nov., to accommodate the two species with Neomicrococcus aestuarii gen. nov., comb. nov. (type strain JCM 16166T = KCTC 19557T) as the type species. Neomicrococcus lactis comb. nov. (type strain MCC 2278T = DSM 23694T) is also proposed.

  15. Probiotic Bifidobacterium species stimulate human SLC26A3 gene function and expression in intestinal epithelial cells

    Science.gov (United States)

    Kumar, Anoop; Hecht, Cameron; Priyamvada, Shubha; Anbazhagan, Arivarasu N.; Alakkam, Anas; Borthakur, Alip; Alrefai, Waddah A.; Gill, Ravinder K.

    2014-01-01

    SLC26A3, or downregulated in adenoma (DRA), plays a major role in mediating Cl− absorption in the mammalian intestine. Disturbances in DRA function and expression have been implicated in intestinal disorders such as congenital Cl− diarrhea and gut inflammation. We previously showed that an increase in DRA function and expression by Lactobacillus acidophilus and its culture supernatant (CS) might underlie antidiarrheal effects of this probiotic strain. However, the effects of Bifidobacterium species, important inhabitants of the human colon, on intestinal Cl−/HCO3− exchange activity are not known. Our current results demonstrate that CS derived from Bifidobacterium breve, Bifidobacterium infantis, and Bifidobacterium bifidum increased anion exchange activity in Caco-2 cells (∼1.8- to 2.4-fold). Consistent with the increase in DRA function, CS also increased the protein, as well as the mRNA, level of DRA (but not putative anion transporter 1). CS of all three Bifidobacterium sp. increased DRA promoter activity (−1,183/+114 bp) in Caco-2 cells (1.5- to 1.8-fold). Furthermore, the increase in DRA mRNA expression by CS of B. breve and B. infantis was blocked in the presence of the transcription inhibitor actinomycin D (5 μM) and the ERK1/2 MAPK pathway inhibitor U0126 (10 μM). Administration of live B. breve, B. infantis, and B. bifidum by oral gavage to mice for 24 h increased DRA mRNA and protein levels in the colon. These data demonstrate an upregulation of DRA via activation of the ERK1/2 pathway that may underlie potential antidiarrheal effects of Bifidobacterium sp. PMID:25143346

  16. Contribution of the CesR-regulated genes llmg0169 and llmg2164-2163 to Lactococcus lactis fitness

    NARCIS (Netherlands)

    Roces, Clara; Campelo, Ana B.; Veiga, Patrick; Pinto, Joao P. C.; Rodriguez, Ana; Martinez, Beatriz

    2009-01-01

    Lactococcus lactis is one of the main components of the starter cultures used in cheese manufacture. As starter, L lactis must tolerate harsh conditions encountered either during their production in bulk quantities or during dairy products processing. To face these hostile conditions, bacteria

  17. Subcutaneous or oral immunization of mice with Lactococcus lactis expressing F4 fimbrial adhesin FaeG.

    Science.gov (United States)

    Liu, Shujie; Li, Yongming; Xu, Ziwei; Wang, Yicheng

    2013-01-01

    Enterotoxigenic Escherichia coli (ETEC) is one of the most common causes of diarrhea in neonatal and postweaning piglets. Fimbrial adhesion of ETEC has been considered an important colonization factor with antigenicity. To safely and effectively deliver the F4 (K88) fimbrial adhesin FaeG to the immune system, we have previously constructed the secretory expression vector pNZ8112-faeG, and FaeG was produced in cytoplasmic form in Lactococcus lactis. In this work, BALB/c mice were immunized with recombinant L. lactis to further determine the immunogenicity of recombinant FaeG (rFaeG) via the subcutaneous or oral route. Subcutaneous immunization in mice with recombinant L. lactis induced a significant increase in the F4-specific serum IgG titer and the number of antibody-secreting cells (ASCs) in the spleen. Oral immunization of mice with recombinant L. lactis induced mucosal and systemic F4-specific immune responses and increased the number of ASCs in the spleen, mesenteric lymph nodes and Peyer's patches. High-dose (2.8 × 10(11) CFU) recombinant strains and adjuvant cholera toxin B subunit enhanced specific mucosal immune responses. The results suggest the feasibility of delivering rFaeG expressed in L. lactis to the immune system in order to induce an F4-specific immune response.

  18. A synbiotic mixture of scGOS/lcFOS and Bifidobacterium breve M-16V increases faecal Bifidobacterium in healthy young children.

    Science.gov (United States)

    Kosuwon, P; Lao-Araya, M; Uthaisangsook, S; Lay, C; Bindels, J; Knol, J; Chatchatee, P

    2018-04-10

    Little is known about the impact of nutrition on toddler gut microbiota. The plasticity of the toddler gut microbiota indicates that nutritional modulation beyond infancy could potentially impact its maturation. The objective of this study was to determine the effect of consuming Young Child Formula (YCF) supplemented with short chain galactooligosaccharides and long chain fructooligosaccharides (scGOS/lcFOS, ratio 9:1) and Bifidobacterium breve M-16V on the development of the faecal microbiota in healthy toddlers. A cohort of 129 Thai children aged 1-3 years were included in a randomised controlled clinical study. The children were assigned to receive either YCF with 0.95 g/100 ml of scGOS/lcFOS and 1.8×10 7 cfu/g of B. breve M-16V (Active-YCF) or Control-YCF for 12 weeks. The composition and metabolic activity of the faecal microbiota, and the level of secretory immunoglobulin A were determined in the stool samples. The consumption of Active-YCF increased the proportion of Bifidobacterium (mean 27.3% at baseline to 33.3%, at week 12, P=0.012) with a difference in change from baseline at week 12 between the Active and Control of 7.48% (P=0.030). The consumption of Active-YCF was accompanied with a more acidic intestinal milieu compared to the Control-YCF. The pH value decreased statistically significantly in the Active-YCF group from a median of 7.05 at baseline to 6.79 at week 12 (Pbreve M-16V positively influences the development of the faecal microbiota in healthy toddlers by supporting higher levels of Bifidobacterium. The synbiotic supplementation is also accompanied with a more acidic intestinal milieu and softer stools.

  19. 49 CFR 173.173 - Paint, paint-related material, adhesives, ink and resins.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Paint, paint-related material, adhesives, ink and... Than Class 1 and Class 7 § 173.173 Paint, paint-related material, adhesives, ink and resins. (a) When..., paint-related material, adhesives, ink and resins must be packaged as follows: (1) As prescribed in...

  20. The major facilitator superfamily transporter Knq1p modulates boron homeostasis in Kluyveromyces lactis.

    Science.gov (United States)

    Svrbicka, Alexandra; Toth Hervay, Nora; Gbelska, Yvetta

    2016-03-01

    Boron is an essential micronutrient for living cells, yet its excess causes toxicity. To date, the mechanisms of boron toxicity are poorly understood. Recently, the ScATR1 gene has been identified encoding the main boron efflux pump in Saccharomyces cerevisiae. In this study, we analyzed the ScATR1 ortholog in Kluyveromyces lactis--the KNQ1 gene, to understand whether it participates in boron stress tolerance. We found that the KNQ1 gene, encoding a permease belonging to the major facilitator superfamily, is required for K. lactis boron tolerance. Deletion of the KNQ1 gene led to boron sensitivity and its overexpression increased K. lactis boron tolerance. The KNQ1 expression was induced by boron and the intracellular boron concentration was controlled by Knq1p. The KNQ1 promoter contains two putative binding motifs for the AP-1-like transcription factor KlYap1p playing a central role in oxidative stress defense. Our results indicate that the induction of the KNQ1 expression requires the presence of KlYap1p and that Knq1p like its ortholog ScAtr1p in S. cerevisiae functions as a boron efflux pump providing boron resistance in K. lactis.

  1. Growth and lactic acid production by Bifidobacterium longum and ...

    African Journals Online (AJOL)

    The fitness of a particular strains of Bifidobacteria, Lactobacilli and Streptococci for commercial utilization depends on its rapid growth and acidification of milk as well as its acid and oxygen tolerence. From 20 samples of French commercial yoghurt, one species of bifidobacteria was identified as Bifidobacterium longum.

  2. The novel sRNA s015 improves nisin yield by increasing acid tolerance of Lactococcus lactis F44.

    Science.gov (United States)

    Qi, Jiakun; Caiyin, Qinggele; Wu, Hao; Tian, Kairen; Wang, Binbin; Li, Yanni; Qiao, Jianjun

    2017-08-01

    Nisin, a polycyclic antibacterial peptide produced by Lactococcus lactis, is stable at low pH. Improving the acid tolerance of L. lactis could thus enhance nisin yield. Small non-coding RNAs (sRNAs) play essential roles in acid tolerance by regulating their target mRNAs at the post-transcriptional level. In this study, a novel sRNA, s015, was identified in L. lactis F44 via the use of RNA sequencing, qRT-PCR analysis, and Northern blotting. s015 improved the acid tolerance of L. lactis and boosted nisin yield at low pH. In silico predictions enabled us to construct a library of possible s015 target mRNAs. Statistical analysis and validation suggested that s015 contains a highly conserved region (5'-GAAAAAAAC-3') that likely encompasses the regulatory core of the sRNA. atpG, busAB, cysD, ilvB, tcsR, ung, yudD, and ywdA were verified as direct targets of s015, and the interactions between s015 and its target genes were elucidated. This work provided new insight into the adaptation mechanism of L. lactis under acid stress.

  3. Protective Effects of Bifidobacterium on Intestinal Barrier Function in LPS-Induced Enterocyte Barrier Injury of Caco-2 Monolayers and in a Rat NEC Model.

    Directory of Open Access Journals (Sweden)

    Xiang Ling

    Full Text Available Zonulin protein is a newly discovered modulator which modulates the permeability of the intestinal epithelial barrier by disassembling intercellular tight junctions (TJ. Disruption of TJ is associated with neonatal necrotizing enterocolitis (NEC. It has been shown bifidobacterium could protect the intestinal barrier function and prophylactical administration of bifidobacterium has beneficial effects in NEC patients and animals. However, it is still unknown whether the zonulin is involved in the gut barrier dysfunction of NEC, and the protective mechanisms of bifidobacterium on intestinal barrier function are also not well understood. The present study aims to investigate the effects of bifidobacterium on intestinal barrier function, zonulin regulation, and TJ integrity both in LPS-induced enterocyte barrier injury of Caco-2 monolayers and in a rat NEC model. Our results showed bifidobacterium markedly attenuated the decrease in transepithelial electrical resistance and the increase in paracellular permeability in the Caco-2 monolayers treated with LPS (P < 0.01. Compared with the LPS group, bifidobacterium significantly decreased the production of IL-6 and TNF-α (P < 0.01 and suppressed zonulin release (P < 0.05. In addition, bifidobacterium pretreatment up-regulated occludin, claudin-3 and ZO-1 expression (P < 0.01 and also preserved these proteins localization at TJ compared with the LPS group. In the in vivo study, bifidobacterium decreased the incidence of NEC from 88 to 47% (P < 0.05 and reduced the severity in the NEC model. Increased levels of IL-6 and TNF-α in the ileum of NEC rats were normalized in bifidobacterium treated rats (P < 0.05. Moreover, administration of bifidobacterium attenuated the increase in intestinal permeability (P < 0.01, decreased the levels of serum zonulin (P < 0.05, normalized the expression and localization of TJ proteins in the ileum compared with animals with NEC. We concluded that bifidobacterium may

  4. DN2 Thymocytes Activate a Specific Robust DNA Damage Response to Ionizing Radiation-Induced DNA Double-Strand Breaks

    Directory of Open Access Journals (Sweden)

    Irene Calvo-Asensio

    2018-06-01

    Full Text Available For successful bone marrow transplantation (BMT, a preconditioning regime involving chemo and radiotherapy is used that results in DNA damage to both hematopoietic and stromal elements. Following radiation exposure, it is well recognized that a single wave of host-derived thymocytes reconstitutes the irradiated thymus, with donor-derived thymocytes appearing about 7 days post BMT. Our previous studies have demonstrated that, in the presence of donor hematopoietic cells lacking T lineage potential, these host-derived thymocytes are able to generate a polyclonal cohort of functionally mature peripheral T cells numerically comprising ~25% of the peripheral T cell pool of euthymic mice. Importantly, we demonstrated that radioresistant CD44+ CD25+ CD117+ DN2 progenitors were responsible for this thymic auto-reconstitution. Until recently, the mechanisms underlying the radioresistance of DN2 progenitors were unknown. Herein, we have used the in vitro “Plastic Thymus” culture system to perform a detailed investigation of the mechanisms responsible for the high radioresistance of DN2 cells compared with radiosensitive hematopoietic stem cells. Our results indicate that several aspects of DN2 biology, such as (i rapid DNA damage response (DDR activation in response to ionizing radiation-induced DNA damage, (ii efficient repair of DNA double-strand breaks, and (iii induction of a protective G1/S checkpoint contribute to promoting DN2 cell survival post-irradiation. We have previously shown that hypoxia increases the radioresistance of bone marrow stromal cells in vitro, at least in part by enhancing their DNA double-strand break (DNA DSB repair capacity. Since the thymus is also a hypoxic environment, we investigated the potential effects of hypoxia on the DDR of DN2 thymocytes. Finally, we demonstrate for the first time that de novo DN2 thymocytes are able to rapidly repair DNA DSBs following thymic irradiation in vivo.

  5. Attentional function and basal forebrain cholinergic neuron morphology during aging in the Ts65Dn mouse model of Down syndrome.

    Science.gov (United States)

    Powers, Brian E; Velazquez, Ramon; Kelley, Christy M; Ash, Jessica A; Strawderman, Myla S; Alldred, Melissa J; Ginsberg, Stephen D; Mufson, Elliott J; Strupp, Barbara J

    2016-12-01

    Individuals with Down syndrome (DS) exhibit intellectual disability and develop Alzheimer's disease-like neuropathology during the third decade of life. The Ts65Dn mouse model of DS exhibits key features of both disorders, including impairments in learning, attention and memory, as well as atrophy of basal forebrain cholinergic neurons (BFCNs). The present study evaluated attentional function in relation to BFCN morphology in young (3 months) and middle-aged (12 months) Ts65Dn mice and disomic (2N) controls. Ts65Dn mice exhibited attentional dysfunction at both ages, with greater impairment in older trisomics. Density of BFCNs was significantly lower for Ts65Dn mice independent of age, which may contribute to attentional dysfunction since BFCN density was positively associated with performance on an attention task. BFCN volume decreased with age in 2N but not Ts65Dn mice. Paradoxically, BFCN volume was greater in older trisomic mice, suggestive of a compensatory response. In sum, attentional dysfunction occurred in both young and middle-aged Ts65Dn mice, which may in part reflect reduced density and/or phenotypic alterations in BFCNs.

  6. Production and secretion of heterologous proteins by Lactococcus lactis

    NARCIS (Netherlands)

    Asseldonk, van M.

    1994-01-01

    Lactococcus lactis strains have been used for centuries in food fermentation, now appreciated as traditional biotechnology. They have been applied in the cheesemaking process and for the manufacturing of other dairy products. Years of experience with these lactic acid

  7. Factors affecting proteolytic action of Lactococcus lactis in cheese

    NARCIS (Netherlands)

    Youssef, Y.B.

    1992-01-01

    Model cheeses were developed to study the behaviour of proteolytic agents involved in cheese maturation under conditions that closely resemble those in normal cheese. The models were applied to study protein breakdown by Lactococcus lactis ssp. cremoris HP , as a

  8. 49 CFR 173.322 - Ethyl chloride.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Ethyl chloride. 173.322 Section 173.322 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... SHIPMENTS AND PACKAGINGS Gases; Preparation and Packaging § 173.322 Ethyl chloride. Ethyl chloride must be...

  9. Intestinal Microbiota in Pediatric Surgical Cases Administered Bifidobacterium Breve: A Randomized Controlled Trial.

    Science.gov (United States)

    Okazaki, Tadaharu; Asahara, Takashi; Yamataka, Atsuyuki; Ogasawara, Yuki; Lane, Geoffrey J; Nomoto, Koji; Nagata, Satoru; Yamashiro, Yuichiro

    2016-07-01

    The efficacy of perioperative probiotic administration has been reported in adults. We examined the effects of orally administered Bifidobacterium breve strain Yakult (BBG-01) on outcomes in pediatric surgical cases by assessing intestinal and blood microbiota. BBG-01 was well tolerated without adverse effects, and postoperative infectious complications were significantly decreased. Fecal analysis showed increased Bifidobacterium and decreased Enterobacteriaceae, Clostridium difficile, and Pseudomonas. Concentrations of fecal acetic acid were significantly increased, maintaining fecal pH at <7.0. The incidence of detecting bacteria in blood was significantly reduced. BBG-01 improved the intestinal environment, and may be implicated in suppressing bacterial translocation.

  10. 49 CFR 173.443 - Contamination control.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Contamination control. 173.443 Section 173.443... SHIPMENTS AND PACKAGINGS Class 7 (Radioactive) Materials § 173.443 Contamination control. (a) The level of non-fixed (removable) radioactive contamination on the external surfaces of each package offered for...

  11. Investigation of glycerol assimilation and cofactor metabolism in Lactococcus lactis

    DEFF Research Database (Denmark)

    Holm, Anders Koefoed

    of glycerol kinase from L. lactis, introduction of a heterologous glycerol assimilation pathway and construction of a library of NADH oxidase activity. Based on a preliminary analysis of transcription level data, an attempt was made to stimulate glycerol assimilation by overexpressing the glycerol kinase...... already present in L. lactis. The construction and verification of a strain with increased glycerol kinase activity was not fully completed and is still ongoing. Similarly the construction of mutants expressing a heterologous pathway for glycerol dissimilation is also an ongoing task. An artificial...... effects and improve the growth rate, though not completely to the level of the reference strain. The fact that this effect was predominantly observed while utilizing xylose implicates the involvement of the pentose phosphate pathway. A possible mechanism underlying the observed growth characteristics...

  12. 21 CFR 173.160 - Candida guilliermondii.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Candida guilliermondii. 173.160 Section 173.160... CONSUMPTION Enzyme Preparations and Microorganisms § 173.160 Candida guilliermondii. The food additive Candida... the following conditions: (a) The food additive is the enzyme system of the viable organism Candida...

  13. Um suplemento entre dois mundos: Causas e consequências da transição papel/digital do DN Jovem

    OpenAIRE

    Freitas, Helena de Sousa

    2012-01-01

    The DN Jovem, a supplement that the Portuguese newspaper Diário de Notícias (DN) began publishing in May 1983, quickly became a showcase for new prose writers, poets, photographers and illustrators. In June 1996, when access to the Internet didn’t even reach one percent of Portuguese homes, its contents migrated from print to online. The transition, determined by the Administration of DN within a newspaper’s restructuring, announced the death of a supplement that was, according to Portuguese ...

  14. The effects of RecO deficiency in Lactococcus lactis NZ9000 on resistance to multiple environmental stresses.

    Science.gov (United States)

    Zhang, Mengru; Chen, Jian; Zhang, Juan; Du, Guocheng

    2014-12-01

    Multiple stresses could cause damage to DNA and other macromolecules. RecO, belonging to the family of DNA repair proteins, plays an important part in homologous recombination and replication repair. In order to explore the role of RecO in overcoming multiple stresses, a mutant of recO deletion is constructed in Lactococcus lactis ssp. cremoris NZ9000. Compared with the mutant strain, the original strain L. lactis NZ9000 shows better performance in growth under multiple stresses. The survival rates of the original strain under acid, osmotic and chill stresses are 13.49-, 2.78- and 60.89-fold higher. In our deeper research on fermentation capability under osmotic stress, lactate dehydrogenase activity after 8 h fermentation, maximum lactate acid production, lactate yield and maximum lactate productivity of L. lactis NZ9000 are 1.63-, 1.28-, 1.28- and 1.5-fold higher, respectively. Results indicate that RecO has positively improved the survival of L. lactis NZ9000, protected its key enzymes and enhanced its fermentation efficiencies. Our research confirms the role of RecO in enhancing tolerances to multiple stresses of L. lactis NZ9000, and puts forward the suggestion that RecO could be used in other industrial microorganisms as a new anti-stress component to improve their resistance to various stresses. © 2014 Society of Chemical Industry.

  15. Microencapsulation and Fermentation of Lactobacillus acidophilus LA-5 and Bifidobacterium BB-12

    Directory of Open Access Journals (Sweden)

    Maryam Yari

    2015-09-01

    Full Text Available Because of poor survival of probiotic bacteria, microencapsulation evolved from the immobilized cell culture technology used in the biotechnological industry. Two probiotic strains, Bifidobacterium (BB-12 and Lactobacillus acidophilus (LA-5 were immobilized in calcium alginate by extrusion method. Encapsulation parameters and efficacy of this method were evaluated. Growth factors of these two bacteria were also measured by culturing in 10-L fermenter. Growth curves were obtained with respect to optical density and dry biomass weight. Encapsulation yield was over than 60% in each experiment. Scanning electron microscopy (SEM of Entrapment of cells in alginate matrix and cross-sections of dried bead were obtained and illustrated. Bifidobacterium have been shown better biotechnological properties.

  16. 21 CFR 173.230 - Ethylene dichloride.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene dichloride. 173.230 Section 173.230 Food... Solvents, Lubricants, Release Agents and Related Substances § 173.230 Ethylene dichloride. A tolerance of 30 parts per million is established for ethylene dichloride in spice oleoresins when present therein...

  17. 21 CFR 173.255 - Methylene chloride.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Methylene chloride. 173.255 Section 173.255 Food... Solvents, Lubricants, Release Agents and Related Substances § 173.255 Methylene chloride. Methylene chloride may be present in food under the following conditions: (a) In spice oleoresins as a residue from...

  18. 21 CFR 173.375 - Cetylpyridinium chloride.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Cetylpyridinium chloride. 173.375 Section 173.375... CONSUMPTION Specific Usage Additives § 173.375 Cetylpyridinium chloride. Cetylpyridinium chloride (CAS Reg. No....1666 of this chapter, at a concentration of 1.5 times that of cetylpyridinium chloride. (c) The...

  19. PpiA, a surface PPIase of the cyclophilin family in Lactococcus lactis.

    Directory of Open Access Journals (Sweden)

    Nicolas Trémillon

    Full Text Available BACKGROUND: Protein folding in the envelope is a crucial limiting step of protein export and secretion. In order to better understand this process in Lactococcus lactis, a lactic acid bacterium, genes encoding putative exported folding factors like Peptidyl Prolyl Isomerases (PPIases were searched for in lactococcal genomes. RESULTS: In L. lactis, a new putative membrane PPIase of the cyclophilin subfamily, PpiA, was identified and characterized. ppiA gene was found to be constitutively expressed under normal and stress (heat shock, H(2O(2 conditions. Under normal conditions, PpiA protein was synthesized and released from intact cells by an exogenously added protease, showing that it was exposed at the cell surface. No obvious phenotype could be associated to a ppiA mutant strain under several laboratory conditions including stress conditions, except a very low sensitivity to H(2O(2. Induction of a ppiA copy provided in trans had no effect i on the thermosensitivity of an mutant strain deficient for the lactococcal surface protease HtrA and ii on the secretion and stability on four exported proteins (a highly degraded hybrid protein and three heterologous secreted proteins in an otherwise wild-type strain background. However, a recombinant soluble form of PpiA that had been produced and secreted in L. lactis and purified from a culture supernatant displayed both PPIase and chaperone activities. CONCLUSIONS: Although L. lactis PpiA, a protein produced and exposed at the cell surface under normal conditions, displayed a very moderate role in vivo, it was found, as a recombinant soluble form, to be endowed with folding activities in vitro.

  20. Bifidobacterium longum and Bifidobacterium breve isolates from preterm and full term neonates: comparison of cell surface properties.

    Science.gov (United States)

    Andriantsoanirina, Valérie; Teolis, Anne-Claire; Xin, Liu Xin; Butel, Marie Jose; Aires, Julio

    2014-08-01

    We compared autoaggregation, surface hydrophobicity and Caco-2 cells adhesion capabilities of independent Bifidobacterium breve (n = 22) and Bifidobacterium longum (n = 25) strains isolated from preterm (n = 20) and full term neonates (n = 27). Concerning strains properties, a correlation between autoaggregation and surface hydrophobicity was found for B. longum (r = 0.40, p = 0.048), B. breve (r = 0.57, p = 0.005), and all strains independently of the species consideration (r = 0.46, p = 0.001). The absence of difference in adhesion capabilities between preterm and full term neonate strains suggests a strain-dependent property. However, B. longum strains from preterm neonates (n = 10) showed higher autoaggregation ability (p = 0.044). Additionally, independently of species consideration, preterm neonates strains showed lower surface hydrophobicity (p = 0.027). As far as species are considered, preterm neonate B. breve strains (n = 10) showed significantly lower surface hydrophobicity percentages (p = 0.043). Our results suggest the existence of variations in bifidobacteria membrane structure and/or composition that may reflect adaptation of these bacteria to the intestinal environment of either preterm or full term neonates. Such information is of interest when considering the use of bifidobacteria probiotic strains for modulation of preterm neonates gut microbiota. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Hematopoietic Stem Cells from Ts65Dn Mice Are Deficient in the Repair of DNA Double-Strand Breaks.

    Science.gov (United States)

    Wang, Yingying; Chang, Jianhui; Shao, Lijian; Feng, Wei; Luo, Yi; Chow, Marie; Du, Wei; Meng, Aimin; Zhou, Daohong

    2016-06-01

    Down syndrome (DS) is a genetic disorder caused by the presence of an extra partial or whole copy of chromosome 21. In addition to musculoskeletal and neurodevelopmental abnormalities, children with DS exhibit various hematologic disorders and have an increased risk of developing acute lymphoblastic leukemia and acute megakaryocytic leukemia. Using the Ts65Dn mouse model, we investigated bone marrow defects caused by trisomy for 132 orthologs of the genes on human chromosome 21. The results showed that, although the total bone marrow cellularity as well as the frequency of hematopoietic progenitor cells (HPCs) was comparable between Ts65Dn mice and their age-matched euploid wild-type (WT) control littermates, human chromosome 21 trisomy led to a significant reduction in hematopoietic stem cell (HSC) numbers and clonogenic function in Ts65Dn mice. We also found that spontaneous DNA double-strand breaks (DSBs) were significantly increased in HSCs from the Ts65Dn mice, which was correlated with the significant reduction in HSC clonogenic activity compared to those from WT controls. Moreover, analysis of the repair kinetics of radiation-induced DSBs revealed that HSCs from Ts65Dn mice were less proficient in DSB repair than the cells from WT controls. This deficiency was associated with a higher sensitivity of Ts65Dn HSCs to radiation-induced suppression of HSC clonogenic activity than that of euploid HSCs. These findings suggest that an additional copy of genes on human chromosome 21 may selectively impair the ability of HSCs to repair DSBs, which may contribute to DS-associated hematological abnormalities and malignancies.

  2. 12 CFR 308.173 - Prevailing party.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Prevailing party. 308.173 Section 308.173 Banks....173 Prevailing party. (a) General rule. An eligible applicant who, following an adversary adjudication has gained victory on the merits in the proceeding is a “prevailing party”. An eligible applicant may...

  3. 49 CFR 173.323 - Ethylene oxide.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Ethylene oxide. 173.323 Section 173.323... SHIPMENTS AND PACKAGINGS Gases; Preparation and Packaging § 173.323 Ethylene oxide. (a) For packaging ethylene oxide in non-bulk packagings, silver mercury or any of its alloys or copper may not be used in any...

  4. Lactococcus lactis, an alternative system for functional expression of peripheral and intrinsic Arabidopsis membrane proteins.

    Directory of Open Access Journals (Sweden)

    Annie Frelet-Barrand

    Full Text Available BACKGROUND: Despite their functional and biotechnological importance, the study of membrane proteins remains difficult due to their hydrophobicity and their low natural abundance in cells. Furthermore, into established heterologous systems, these proteins are frequently only produced at very low levels, toxic and mis- or unfolded. Lactococcus lactis, a gram-positive lactic bacterium, has been traditionally used in food fermentations. This expression system is also widely used in biotechnology for large-scale production of heterologous proteins. Various expression vectors, based either on constitutive or inducible promoters, are available for this system. While previously used to produce bacterial and eukaryotic membrane proteins, the ability of this system to produce plant membrane proteins was until now not tested. METHODOLOGY/PRINCIPAL FINDINGS: The aim of this work was to test the expression, in Lactococcus lactis, of either peripheral or intrinsic Arabidopsis membrane proteins that could not be produced, or in too low amount, using more classical heterologous expression systems. In an effort to easily transfer genes from Gateway-based Arabidopsis cDNA libraries to the L. lactis expression vector pNZ8148, we first established a cloning strategy compatible with Gateway entry vectors. Interestingly, the six tested Arabidopsis membrane proteins could be produced, in Lactococcus lactis, at levels compatible with further biochemical analyses. We then successfully developed solubilization and purification processes for three of these proteins. Finally, we questioned the functionality of a peripheral and an intrinsic membrane protein, and demonstrated that both proteins were active when produced in this system. CONCLUSIONS/SIGNIFICANCE: Altogether, these data suggest that Lactococcus lactis might be an attractive system for the efficient and functional production of difficult plant membrane proteins.

  5. Structure and properties of the metastable bacteriocin Lcn972 from Lactococcus lactis

    Science.gov (United States)

    Turner, David L.; Lamosa, Pedro; Rodríguez, Ana; Martínez, Beatriz

    2013-01-01

    Lactococcus lactis subsp. lactis IPLA 972 produces a polypeptide bacteriocin of 7.5 kDa which has a bactericidal effect on sensitive lactococci, inhibiting septum formation in dividing cells. The active form is a monomer that is metastable under normal conditions but is stabilised by glycerol. The NMR structure of Lcn972 shows a β-sandwich comprising two three-stranded antiparallel β-sheets. Detaching the final strand could allow the sandwich to open, and the irreversible unfolding leads to a loss of antibacterial activity. Covalent linkage of the final strand should increase the stability of Lcn972 and facilitate the study of its interaction with lipid II.

  6. Lactococcus lactis NCC 2287 Alleviates Food Allergic Manifestations in Sensitized Mice by Reducing IL-13 Expression Specifically in the Ileum

    Directory of Open Access Journals (Sweden)

    Adrian W. Zuercher

    2012-01-01

    Full Text Available Objective. Utilizing a food allergy murine model, we have investigated the intrinsic antiallergic potential of the Lactococcus lactis NCC 2287 strain. Methods. BALB/c mice were sensitized at weekly intervals with ovalbumin (OVA plus cholera toxin (CT by the oral route for 7 weeks. In this model, an oral challenge with a high dose of OVA at the end of the sensitization period leads to clinical symptoms. Lactococcus lactis NCC 2287 was given to mice via the drinking water during sensitization (prevention phase or after sensitization (management phase. Results. Lactococcus lactis NCC 2287 administration to sensitized mice strikingly reduced allergic manifestations in the management phase upon challenge, when compared to control mice. No preventive effect was observed with the strain. Lactococcus lactis NCC 2287 significantly decreased relative expression levels of the Th-2 cytokine, IL-13, and associated chemokines CCL11 (eotaxin-1 and CCL17 (TARC in the ileum. No effect was observed in the jejunum. Conclusion/Significance. These results taken together designate Lactococcus lactis NCC 2287 as a candidate probiotic strain appropriate in the management of allergic symptoms.

  7. Transcriptome profiling of Lactococcus lactis subsp. cremoris CECT 8666 in response to agmatine

    Directory of Open Access Journals (Sweden)

    Beatriz del Rio

    2016-03-01

    Full Text Available The dairy strain Lactococcus lactis subsp. cremoris CECT 8666 (formerly GE2-14 synthesizes the biogenic amine putrescine from agmatine via the agmatine deiminase (AGDI pathway [1]. The AGDI cluster of L. lactis is composed by five genes aguR, aguB, aguD, aguA and aguC. The last four genes are co-transcribed as a single policistronic mRNA forming the catabolic operon aguBDAC, which encodes the proteins necessary for agmatine uptake and its conversion into putrescine [1,2]. The first gene of the cluster, aguR, encodes a transmembrane protein that functions as a one-component signal transduction system that senses the agmatine concentration of the medium and accordingly regulates the transcription of aguBDAC [2]. The catabolic operon aguBDAC is transcriptionally activated by agmatine [2] and transcriptionally regulated by carbon catabolite repression (CCR via glucose, but not by other sugars such as lactose or galactose [1,3]. On the contrary, the transcription of the aguR regulatory gene is not subject to CCR regulation [1,3] nor is regulated by agmatine [2]. In this study we report the transcriptional profiling of L. lactis subsp. cremoris CECT 8666 grown in M17 medium with galactose (GalM17 as carbon source and supplemented with agmatine, compared to that of the strain grown in the same culture medium without agmatine. The transcriptional profiling data of agmatine-regulated genes were deposited in the Gene Expression Omnibus (GEO database under Accession no. GSE74808. Keywords: Lactococcus lactis, Biogenic amines, Putrescine, Agmatine deiminase, Agmatine

  8. Recombinant Lactococcus lactis Expressing Haemagglutinin from a Polish Avian H5N1 Isolate and Its Immunological Effect in Preliminary Animal Trials

    Directory of Open Access Journals (Sweden)

    Agnieszka K. Szczepankowska

    2017-01-01

    Full Text Available Lactic acid bacteria (LAB are Gram-positive, nonpathogenic microorganisms that are gaining much interest as antigen producers for development of live vaccine vectors. Heterologous proteins of different origin have been successfully expressed in various LAB species, including Lactococcus lactis. Recombinant L. lactis strains have been shown to induce specific local and systemic immune responses against various antigens. Our study aimed at constructing a L. lactis strain expressing haemagglutinin of a Polish avian H5H1 influenza isolate and examining its effect on animals. Expression of the cloned H5 gene was achieved using the nisin-controlled gene expression system. Detection of the intracellular H5 antigen produced in L. lactis was performed by Western blot analysis and confirmed using mass spectrometry. The potential of L. lactis recombinant cells to induce an immune response was examined by setting up preliminary immunization trials on chickens and mice. Obtained sera were tested for specific antibodies by ELISA assays. The results of these studies are a promising step toward developing a vaccine against the bird flu using Lactococcus lactis cells as bioreactors for efficient antigen production and delivery to the mucosal surface.

  9. Recombinant Lactococcus lactis Expressing Haemagglutinin from a Polish Avian H5N1 Isolate and Its Immunological Effect in Preliminary Animal Trials.

    Science.gov (United States)

    Szczepankowska, Agnieszka K; Szatraj, Katarzyna; Sałański, Przemysław; Rózga, Agnieszka; Górecki, Roman K; Bardowski, Jacek K

    2017-01-01

    Lactic acid bacteria (LAB) are Gram-positive, nonpathogenic microorganisms that are gaining much interest as antigen producers for development of live vaccine vectors. Heterologous proteins of different origin have been successfully expressed in various LAB species, including Lactococcus lactis . Recombinant L. lactis strains have been shown to induce specific local and systemic immune responses against various antigens. Our study aimed at constructing a L. lactis strain expressing haemagglutinin of a Polish avian H5H1 influenza isolate and examining its effect on animals. Expression of the cloned H5 gene was achieved using the nisin-controlled gene expression system. Detection of the intracellular H5 antigen produced in L. lactis was performed by Western blot analysis and confirmed using mass spectrometry. The potential of L. lactis recombinant cells to induce an immune response was examined by setting up preliminary immunization trials on chickens and mice. Obtained sera were tested for specific antibodies by ELISA assays. The results of these studies are a promising step toward developing a vaccine against the bird flu using Lactococcus lactis cells as bioreactors for efficient antigen production and delivery to the mucosal surface.

  10. Modulation of gut microbiota and increase in fecal water content in mice induced by administration of Lactobacillus kefiranofaciens DN1.

    Science.gov (United States)

    Jeong, Dana; Kim, Dong-Hyeon; Kang, Il-Byeong; Kim, Hyunsook; Song, Kwang-Young; Kim, Hong-Seok; Seo, Kun-Ho

    2017-02-22

    Lactobacillus kefiranofaciens is the key probiotic bacterium in kefir. In this study, we investigated the effects of oral consumption of L. kefiranofaciens on the fecal quality and intestinal microbiota of mice. Four-week-old Balb/c mice were divided into two groups (n = 8 each) and administered 0.2 mL of saline (control group) or saline containing 2 × 10 8 cfu L. kefiranofaciens DN1 (LKF_DN1 group) for two weeks. At the end of the experiment, their fecal samples were collected and the fecal quality and microbiota were assessed. The LKF_DN1 group exhibited higher total fecal weight and fecal weight per stool sample than the control group (p kefiranofaciens DN1 administration could alleviate constipation and improve gut microbiota.

  11. Diversity of the subspecies Bifidobacterium animalis subsp lactis

    Czech Academy of Sciences Publication Activity Database

    Bunešová, V.; Killer, Jiří; Javůrková, B.; Vlková, E.; Tejnecký, V.; Musilová, S.; Rada, V.

    2017-01-01

    Roč. 44, č. 1 (2017), s. 40-47 ISSN 1075-9964 Institutional support: RVO:67985904 Keywords : bifidobacteria * environment * origin Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 2.278, year: 2016

  12. Sec-mediated secretion of bacteriocin enterocin P by Lactococcus lactis

    NARCIS (Netherlands)

    Herranz, C; Driessen, AJM

    Most lactic acid bacterium bacteriocins utilize specific leader peptides and dedicated machineries for secretion. In contrast, the enterococcal bacteriocin enterocin P (EntP) contains a typical signal peptide that directs its secretion when heterologously expressed in Lactococcus lactis. Signal

  13. Statistical optimization of lactic acid production by Lactococcus lactis ...

    African Journals Online (AJOL)

    The individual and interactive effects of a total inoculums size (% v/v), fermentation temperature and skim milk dry matter added (% w/v) on the lactic acid production by Lactococcus lactis LCL strain were studied by quadratic response surface methodology. The central composite design (CCD) was employed to determine ...

  14. Cross-feeding by Bifidobacterium breve UCC2003 during co-cultivation with Bifidobacterium bifidum PRL2010 in a mucin-based medium.

    Science.gov (United States)

    Egan, Muireann; Motherway, Mary O'Connell; Kilcoyne, Michelle; Kane, Marian; Joshi, Lokesh; Ventura, Marco; van Sinderen, Douwe

    2014-11-25

    Bifidobacteria constitute a specific group of commensal bacteria that commonly inhabit the mammalian gastrointestinal tract. Bifidobacterium breve UCC2003 was previously shown to utilize a variety of plant/diet/host-derived carbohydrates, including cellodextrin, starch and galactan, as well as the mucin and HMO-derived monosaccharide, sialic acid. In the current study, we investigated the ability of this strain to utilize parts of a host-derived source of carbohydrate, namely the mucin glycoprotein, when grown in co-culture with the mucin-degrading Bifidobacterium bifidum PRL2010. B. breve UCC2003 was shown to exhibit growth properties in a mucin-based medium, but only when grown in the presence of B. bifidum PRL2010, which is known to metabolize mucin. A combination of HPAEC-PAD and transcriptome analyses identified some of the possible monosaccharides and oligosaccharides which support this enhanced co-cultivation growth/viability phenotype. This study describes the potential existence of a gut commensal relationship between two bifidobacterial species. We demonstrate the in vitro ability of B. breve UCC2003 to cross-feed on sugars released by the mucin-degrading activity of B. bifidum PRL2010, thus advancing our knowledge on the metabolic adaptability which allows the former strain to colonize the (infant) gut by its extensive metabolic abilities to (co-)utilize available carbohydrate sources.

  15. Developing a xylanase XYNZG from Plectosphaerella cucumerina for baking by heterologously expressed in Kluyveromyces lactis.

    Science.gov (United States)

    Zhan, Fei Xiang; Wang, Qin Hong; Jiang, Si Jing; Zhou, Yu Ling; Zhang, Gui Min; Ma, Yan He

    2014-12-16

    Xylanase can replace chemical additives to improve the volume and sensory properties of bread in the baking. Suitable baking xylanase with improved yield will promote the application of xylanase in baking industry. The xylanase XYNZG from the Plectosphaerella cucumerina has been previously characterized by heterologous expression in Pichia pastoris. However, P. pastoris is not a suitable host for xylanase to be used in the baking process since P. pastoris does not have GRAS (Generally Regarded As Safe) status and requires large methanol supplement during the fermentation in most conditions, which is not allowed to be used in the food industry. Kluyveromyces lactis, as another yeast expression host, has a GRAS status, which has been successfully used in food and feed applications. No previous work has been reported concerning the heterologous expression of xylanase gene xynZG in K. lactis with an aim for application in baking. The xylanase gene xynZG from the P. cucumerina was heterologously expressed in K. lactis. The recombinant protein XYNZG in K. lactis presented an approximately 19 kDa band on SDS-PAGE and zymograms analysis. Transformant with the highest halo on the plate containing the RBB-xylan (Remazol Brilliant Blue-xylan) was selected for the flask fermentation in different media. The results indicated that the highest activity of 115 U/ml at 72 h was obtained with the YLPU medium. The mass spectrometry analysis suggested that the hydrolytic products of xylan by XYNZG were mainly xylobiose and xylotriose. The results of baking trials indicated that the addition of XYNZG could reduce the kneading time of dough, increase the volume of bread, improve the texture, and have more positive effects on the sensory properties of bread. Xylanase XYNZG is successfully expressed in K. lactis, which exhibits the highest activity among the published reports of the xylanase expression in K. lactis. The recombinant XYNZG can be used to improve the volume and sensory

  16. Quantification of Human Fecal Bifidobacterium Species by Use of Quantitative Real-Time PCR Analysis Targeting the groEL Gene

    Science.gov (United States)

    Junick, Jana

    2012-01-01

    Quantitative real-time PCR assays targeting the groEL gene for the specific enumeration of 12 human fecal Bifidobacterium species were developed. The housekeeping gene groEL (HSP60 in eukaryotes) was used as a discriminative marker for the differentiation of Bifidobacterium adolescentis, B. angulatum, B. animalis, B. bifidum, B. breve, B. catenulatum, B. dentium, B. gallicum, B. longum, B. pseudocatenulatum, B. pseudolongum, and B. thermophilum. The bifidobacterial chromosome contains a single copy of the groEL gene, allowing the determination of the cell number by quantification of the groEL copy number. Real-time PCR assays were validated by comparing fecal samples spiked with known numbers of a given Bifidobacterium species. Independent of the Bifidobacterium species tested, the proportion of groEL copies recovered from fecal samples spiked with 5 to 9 log10 cells/g feces was approximately 50%. The quantification limit was 5 to 6 log10 groEL copies/g feces. The interassay variability was less than 10%, and variability between different DNA extractions was less than 23%. The method developed was applied to fecal samples from healthy adults and full-term breast-fed infants. Bifidobacterial diversity in both adults and infants was low, with mostly ≤3 Bifidobacterium species and B. longum frequently detected. The predominant species in infant and adult fecal samples were B. breve and B. adolescentis, respectively. It was possible to distinguish B. catenulatum and B. pseudocatenulatum. We conclude that the groEL gene is a suitable molecular marker for the specific and accurate quantification of human fecal Bifidobacterium species by real-time PCR. PMID:22307308

  17. 46 CFR 173.010 - Definitions.

    Science.gov (United States)

    2010-10-01

    ... VESSEL USE Lifting § 173.010 Definitions. As used in this part— (a) Hook load means the weight of the object lifted by the crane. (b) Crane radius means the distance illustrated in Figure 173.010. EC01MR91...

  18. Preferential localization of Lactococcus lactis cells entrapped in a caseinate/alginate phase separated system.

    Science.gov (United States)

    Léonard, Lucie; Gharsallaoui, Adem; Ouaali, Fahima; Degraeve, Pascal; Waché, Yves; Saurel, Rémi; Oulahal, Nadia

    2013-09-01

    This study aimed to entrap bioprotective lactic acid bacteria in a sodium caseinate/sodium alginate aqueous two-phase system. Phase diagram at pH=7 showed that sodium alginate and sodium caseinate were not miscible when their concentrations exceeded 1% (w/w) and 6% (w/w), respectively. The stability of the caseinate/alginate two-phase system was also checked at pH values of 6.0 and 5.5. Lactococcus lactis subsp. lactis LAB3 cells were added in a 4% (w/w) caseinate/1.5% (w/w) alginate two-phase system at pH=7. Fluorescence microscopy allowed to observe that the caseinate-rich phase formed droplets dispersed in a continuous alginate-rich phase. The distribution of bacteria in such a system was observed by epifluorescence microscopy: Lc. lactis LAB3 cells stained with Live/Dead(®) Baclight kit™ were located exclusively in the protein phase. Since zeta-potential measurements indicated that alginate, caseinate and bacterial cells all had an overall negative charge at pH 7, the preferential adhesion of LAB cells was assumed to be driven by hydrophobic effect or by depletion phenomena in such biopolymeric systems. Moreover, LAB cells viability was significantly higher in the ternary mixture obtained in the presence of both caseinate and alginate than in single alginate solution. Caseinate/alginate phase separated systems appeared thus well suited for Lc. lactis LAB3 cells entrapment. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Antimicrobial potential for the combination of bovine lactoferrin or its hydrolysate with lactoferrin-resistant probiotics against foodborne pathogens.

    Science.gov (United States)

    Chen, P-W; Jheng, T T; Shyu, C-L; Mao, F C

    2013-03-01

    Previous reports have shown that several probiotic strains can resist the antibacterial activity of bovine lactoferrin (bLf), but the results are inconsistent. Moreover, a portion of orally administered apo-bLf is digested in vivo by pepsin to yield bLf hydrolysate, which produces stronger antibacterial activity than that observed with apo-bLf. However, whether bLf hydrolysate affects the growth of probiotic strains is unclear. Therefore, various probiotic strains in Taiwan were collected and evaluated for activity against apo-bLf and bLf hydrolysate in vitro. Thirteen probiotic strains were evaluated, and the growth of Lactobacillus acidophilus ATCC 4356, Lactobacillus salivarius ATCC 11741, Lactobacillus rhamnosus ATCC 53103, Bifidobacterium longum ATCC 15707, and Bifidobacterium lactis BCRC 17394 were inhibited by both apo-bLf and bLf hydrolysate. The growth of 8 strains were not affected by apo-bLf and bLf hydrolysate, including L. rhamnosus ATCC 7469, Lactobacillus reuteri ATCC 23272, Lactobacillus fermentum ATCC 11739, Lactobacillus coryniformis ATCC 25602, L. acidophilus BCRC 14065, Bifidobacterium infantis ATCC 15697, Bifidobacterium bifidum ATCC 29521, and Pediococcus acidilactici ATCC 8081. However, apo-bLf and its hydrolysate inhibited the growth of foodborne pathogens, including Escherichia coli, Salmonella typhimurium, Staphylococcus aureus, and Enterococcus faecalis. Moreover, the supernatants produced by L. fermentum, B. lactis, and B. longum inhibited the growth of most pathogens. Importantly, a combination of apo-bLf or bLf hydrolysate with the supernatants of cultures of the organisms described above showed synergistic or partially synergistic effects against the growth of most of the selected pathogens. In conclusion, several probiotic strains are resistant to apo-bLf and bLf hydrolysate, warranting clinical studies to evaluate the antimicrobial potential for the combination of apo-bLf or its hydrolysate with specific probiotics. Copyright

  20. Oxidative Stress at High Temperatures in Lactococcus lactis Due to an Insufficient Supply of Riboflavin

    DEFF Research Database (Denmark)

    Chen, Jun; Shen, Jing; Solem, Christian

    2013-01-01

    Lactococcus lactis MG1363 was found to be unable to grow at temperatures above 37°C in a defined medium without riboflavin, and the cause was identified to be dissolved oxygen introduced during preparation of the medium. At 30°C, growth was unaffected by dissolved oxygen and oxygen was consumed...... riboflavin to the medium, it was possible to improve growth and oxygen consumption at 37°C, and this also normalized the [ATP]-to-[ADP] ratio. A codon-optimized redox-sensitive green fluorescent protein (GFP) was introduced into L. lactis and revealed a more oxidized cytoplasm at 37°C than at 30°C....... These results indicate that L. lactis suffers from heat-induced oxidative stress at increased temperatures. A decrease in intracellular flavin adenine dinucleotide (FAD), which is derived from riboflavin, was observed with increasing growth temperature, but the presence of riboflavin made the decrease smaller...

  1. Variations in the post-weaning human gut metagenome profile as result of Bifidobacterium acquisition in the Western microbiome

    Directory of Open Access Journals (Sweden)

    Matteo Soverini

    2016-07-01

    Full Text Available Studies of the gut microbiome variation among human populations revealed the existence of robust compositional and functional layouts matching the three subsistence strategies that describe a trajectory of changes across our recent evolutionary history: hunting and gathering, rural agriculture, and urban post-industrialized agriculture. In particular, beside the overall reduction of ecosystem diversity, the gut microbiome of Western industrial populations is typically characterized by the loss of Treponema and the acquisition of Bifidobacterium as an abundant inhabitant of the post-weaning gut microbial ecosystem. In order to advance the hypothesis about the possible adaptive nature of this exchange, here we explore specific functional attributes that correspond to the mutually exclusive presence of Treponema and Bifidobacterium using publically available gut metagenomic data from Hadza hunter-gatherers and urban industrial Italians. According to our findings, Bifidobacterium provides the enteric ecosystem with a diverse panel of saccharolytic functions, well suited to the array of gluco- and galacto-based saccharides that abound in the Western diet. On the other hand, the metagenomic functions assigned to Treponema are more predictive of a capacity to incorporate complex polysaccharides, such as those found in unrefined plant foods, which are consistently incorporated in the Hadza diet. Finally, unlike Treponema, the Bifidobacterium metagenome functions include genes that permit the establishment of microbe-host immunological cross-talk, suggesting recent co-evolutionary events between the human immune system and Bifidobacterium that are adaptive in the context of agricultural subsistence and sedentary societies.

  2. Lactococcus lactis Subsp. Lactis Suşlarında Yüksek Sıklıkta Konjugal Transfer Sistemlerinin Analizi

    Directory of Open Access Journals (Sweden)

    Çağla Tükel

    2015-02-01

    Full Text Available Bu çalışmada L. lactis subsp. lactis suşlarında laktoz fermentasyonu özelliğini kodlayan altı farklı plazmidin yüksek sıklıkta konjugal aktarım yeteneği araştırıldı. Bu plazmidlerin konjugal transfer sıklıkları; iki seks faktörünün interaksiyonuna bağlı olarak (Clu ve Agg, Clu-/Agg-, Agg+ x Clu-/Agg+, Agg- ya da Clu+/Agg- x Clu-/Agg- konjugasyon eşleri için 1.5x10-5–1.0x10-7 ve Clu+/Agg- x Clu-/Agg+ konjugasyon eşleri için 7.1x10-2-2.7x10-3 oranlarında değişim gösterdi. Laktoz plazmidlerinin stabiliteleri ise; doğal suşlarda %82-96, MG1390 alıcı suşu için tanımlanan konjugantlarda %77-98 ve MCL8060 alıcı suşu için tanımlanan konjugantlarda ise %44-67 arasında saptandı.

  3. Proteome analysis of a Lactococcus lactis strain overexpressing gapA suggests that the gene product is an auxiliary glyceraldehyde 3-phosphate dehydrogenase

    DEFF Research Database (Denmark)

    Willemoes, Martin; Kilstrup, Mogens; Roepstorff, P.

    2002-01-01

    revealed two neighbouring protein spots, GapBI and GapBII, with amino terminal sequences identical to the product of gapA from the L. lactis subspecies cremoris strain LM0230 and that of the two IL1403 sequences. In order to assign the two protein spots to their respective genes we constructed an L. lactis...... was specific for NAD. No NADP dependent activity was detected. Proteome analysis of the gapA overexpressing strain revealed two new protein spots, GapAI and GapAII, not previously detected in proteome analysis of MG1363. Results from mass spectrometry analysis of GapA and GapB and comparison with the deduced......The sequence of the genome from the Lactococcus lactis subspecies lactis strain IL1403 shows the presence of two reading frames, gapA and gapB, putatively encoding glyceraldehyde 3-phosphate dehydrogenase (GAPDH). Previous proteomic analysis of the L. lactis subspecies cremoris strain MG1363 has...

  4. Lactococcus lactis as host for overproduction of functional membrane proteins

    NARCIS (Netherlands)

    Kunji, ERS; Slotboom, DJ; Poolman, B

    2003-01-01

    Lactococcus lactis has many properties that are ideal for enhanced expression of membrane proteins. The organism is easy and inexpensive to culture, has a single membrane and relatively mild proteolytic activity. Methods for genetic manipulation are fully established and a tightly controlled

  5. Nucleotide metabolism in Lactococcus lactis: Salvage pathways of exogenous pyrimidines

    DEFF Research Database (Denmark)

    Martinussen, Jan; Andersen, Paal Skytt; Hammer, Karin

    1994-01-01

    By measuring enzyme activities in crude extracts and studying the effect of toxic analogs (5-fluoropyrimidines) on cell growth, the metabolism of pyrimidines in Lactococcus lactis was analyzed. Pathways by which uracil, uridine, deoxyuridine, cytidine, and deoxycytidine are metabolized in L. lact...

  6. Two nucleoside transporters in Lactococcus lactis with different substrate specificities

    DEFF Research Database (Denmark)

    Martinussen, Jan; Sørensen, Claus; Jendresen, Christian Bille

    2010-01-01

    , and the utilization of nucleotides is dependent on exogenous phosphatases. The composition of transporters with specificity for purine and pyrimidine nucleosides and nucleobases is subject to variation. The ability of Lactococcus lactis to transport different nucleosides across the cell membrane was characterized...

  7. Development and evaluation of an efficient heterologous gene knock-in reporter system in Lactococcus lactis.

    Science.gov (United States)

    Lu, Yifei; Yan, Hongxiang; Deng, Jiezhong; Huang, Zhigang; Jin, Xurui; Yu, Yanlan; Hu, Qiwen; Hu, Fuquan; Wang, Jing

    2017-09-18

    Lactococcus lactis is a food grade probiotics and widely used to express heterologous proteins. Generally, target genes are knocked into the L. lactis genome through double-crossover recombination to express heterologous proteins stably. However, creating marker-less heterologous genes knocked-in clones is laborious. In this study, an efficient heterologous gene knock-in reporter system was developed in L. lactis NZ9000. Our knock-in reporter system consists of a temperature-sensitive plasmid pJW and a recombinant L. lactis strain named NZB. The pJW contains homologous arms, and was constructed to knock-in heterologous genes at a fixed locus of NZ9000 genome. lacZ (β-galactosidase) gene was knocked into the chromosome of NZ9000 as a counter-selective marker through the plasmid pJW to generate NZB. The engineered NZB strain formed blue colonies on X-Gal plate. The desired double-crossover mutants formed white colonies distinctive from the predominantly blue colonies (parental and plasmid-integrated clones) when the embedded lacZ was replaced with the target heterologous genes carried by pJW in NZB. By using the system, the heterologous gene knocked-in clones are screened by colony phenotype change rather than by checking colonies individually. Our new knock-in reporter system provides an efficient method to create heterologous genes knocked-in clones.

  8. Non-fusion and fusion expression of beta-galactosidase from Lactobacillus bulgaricus in Lactococcus lactis.

    Science.gov (United States)

    Wang, Chuan; Zhang, Chao-Wu; Liu, Heng-Chuan; Yu, Qian; Pei, Xiao-Fang

    2008-10-01

    To construct four recombinant Lactococcus lactis strains exhibiting high beta-galactosidase activity in fusion or non-fusion ways, and to study the influence factors for their protein expression and secretion. The gene fragments encoding beta-galactosidase from two strains of Lactobacillus bulgaricus, wch9901 isolated from yogurt and 1.1480 purchased from the Chinese Academy of Sciences, were amplified and inserted into lactococcal expression vector pMG36e. For fusion expression, the open reading frame of the beta-galactosidase gene was amplified, while for non-fusion expression, the open reading frame of the beta-galactosidase gene was amplified with its native Shine-Dalgarno sequence upstream. The start codon of the beta-galactosidase gene partially overlapped with the stop codon of vector origin open reading frame. Then, the recombinant plasmids were transformed into Escherichia coli DH5 alpha and Lactococcus lactis subsp. lactis MG1363 and confirmed by determining beta-galactosidase activities. The non-fusion expression plasmids showed a significantly higher beta-galactosidase activity in transformed strains than the fusion expression plasmids. The highest enzyme activity was observed in Lactococcus lactis transformed with the non-fusion expression plasmids which were inserted into the beta-galactosidase gene from Lactobacillus bulgaricus wch9901. The beta-galactosidase activity was 2.75 times as high as that of the native counterpart. In addition, beta-galactosidase expressed by recombinant plasmids in Lactococcus lactis could be secreted into the culture medium. The highest secretion rate (27.1%) was observed when the culture medium contained 20 g/L of lactose. Different properties of the native bacteria may have some effects on the protein expression of recombinant plasmids. Non-fusion expression shows a higher enzyme activity in host bacteria. There may be a host-related weak secretion signal peptide gene within the structure gene of Lb. bulgaricus beta

  9. Effect of using different probiotic cultures on properties of Torba (strained yoghurt

    Directory of Open Access Journals (Sweden)

    Harun Kesenkaş

    2010-03-01

    Full Text Available The viability of Lactobacillus casei LAFTI® L26, Bifidobacterium animalis subsp. lactis LAFTI® B94 and Lactobacillus acidophilus LAFTI® L10, their proteolytic activities and effects on chemical, textural and sensory properties of Torba yoghurts were assessed during 14 days of storage at 4 °C. These probiotic cultures were separately added after the fermentation of milk with yoghurt culture but prior to packaging of the product. Probiotic bacteria reached the recommended level of 6 log cfu/g in Torba yoghurt except B. animalis subsp. lactis B94. The addition of probiotic bacteria resulted in an appreciable proteolytic activity but also textural defects due to the lower total solid content in the final product.

  10. , 971, 975, 983, 985, 994, 996, 998, 1006, 1014), decreasing potentially pathogenic gastro-intestinal microorganisms (ID 960, 967, 969, 971, 975, 983, 985, 994, 996, 998, 1006, 1014), and stimulation of immunological responses (ID 962, 968, 970, 972, 976, 984, 986, 995, 997, 999, 1007, 1015) (further, assessment) pursuant to Article 13(1) of Regulation (EC) No 1924/2006

    DEFF Research Database (Denmark)

    Tetens, Inge

    Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to provide a scientific opinion on health claims pursuant to Article 13 of Regulation (EC) No 1924/2006 in the framework of further assessment related to various microorganisms...... and changes in bowel function, and digestion and absorption of nutrients, decreasing potentially pathogenic gastro-intestinal microorganisms, and stimulation of immunological responses. The food constituents, Bifidobacterium animalis subsp. lactis THT 010801, Bifidobacterium longum subsp. infantis THT 010201...... 030802, Lactobacillus salivarius THT 031001 and Streptococcus thermophilus THT 070102, are sufficiently characterised. The evidence provided did not establish that the proposed claimed effect, stimulation of immunological responses, is a beneficial physiological effect. The references provided...

  11. CINÉTICA, PRUEBA DE CRECIMIENTO Y EFECTO DE INHIBICIÓN DE Lactococcus lactis SOBRE Yersinia pseudotuberculosis

    Directory of Open Access Journals (Sweden)

    HENRY JURADO GÁMEZ

    2016-12-01

    Full Text Available Lactic acid bacteria have demonstrated a high ability to inhibit pathogenic microorganisms, which improve knowledge of such microorganisms is important, for this, the kinetics was determined, growth and the inhibition effect of Lactococcus lactis on Yersinia pseudotuberculosis. The research was conducted at the University of Nariño, by susceptibility testing in all strains; in vitro inhibition of Lc. lactis and supernatant on bacterial pathogen; gastrointestinal lactic strain testing (gas production and catalase, bile, bile salts and 2 temperatures, growth kinetics and HPLC determination of peptides in the supernatant. dicloxacillin resistance was found in both strains. Lactic strain and the supernatant inhibited Y. pseudotuberculosis. growths and 3,9x1010 3x1011 CFU/150 uL to 3 to 5% bile salts, 3x1011 5x1012 and CFU/150 uL 1 and 2% bovine 3x1013 and 3x1012 bile and CFU/150 uL was found 38 and 45°C. The logarithmic phase of Lc. lactis was found at 3 hours with values 6,4x1012 CFU/150 uL. The VAL-TIR-VAL peptide was found in the supernatant. It is concluded that Lc lactis shows probiotic characteristics in in vitro conditions.

  12. Oral Vaccination with the Porcine Rotavirus VP4 Outer Capsid Protein Expressed by Lactococcus lactis Induces Specific Antibody Production

    Directory of Open Access Journals (Sweden)

    Yi-jing Li

    2010-01-01

    Full Text Available The objective of this study to design a delivery system resistant to the gastrointestinal environment for oral vaccine against porcine rotavirus. Lactococcus lactis NZ9000 was transformed with segments of vP4 of the porcine rotavirus inserted into the pNZ8112 surface-expression vector, and a recombinant L. lactis expressing VP4 protein was constructed. An approximately 27 kDa VP4 protein was confirmed by SDS-PAGE , Western blot and immunostaining analysis. BALB/c mice were immunized orally with VP4-expression recombinant L. lactis and cellular, mucosal and systemic humoral immune responses were examined. Specific anti-VP4 secretory IgA and IgG were found in feces, ophthalmic and vaginal washes and in serum. The induced antibodies demonstrated neutralizing effects on porcine rotavirus infection on MA104 cells. Our findings suggest that oral immunization with VP4-expressing L. lactis induced both specific local and systemic humoral and cellular immune responses in mice.

  13. Characterization of the Fermentation Process and the Inhibition Effect of Lactobacillus lactis in Staphylococcus aureus and Staphylococcus epidermidis

    Directory of Open Access Journals (Sweden)

    Henry Jurado-Gámez

    2015-09-01

    Full Text Available The fermentative process and in vitro inhibition of L. lactis in Staphylococcus aureus and Staphylococcus epidermidis were assessed. The growth of L. lactis at three pH (2.5, 4.5 and 7, bile salts (0.5, 1 and 2 %, bovine bile (1 and 1.2 % and two temperatures (38 and 45 °C were evaluated. Peptides and organic acids in supernatant of L. lactis by HPLC were determined. Fermentation kinetics was carried out, evaluating: pH, total sugar, protein and lactic acid. An antibiogram of dicloxacilin, cefepime, penilicin and cefalotin was made. The inhibition of L. lactis and its supernatant were defined in pathogenic strains. The best growth was at a pH of 2.5 (3 × 1012 UFC/ml; of 1 × 1010 and 4 × 109 UFC/ml for 0.5 % of bile salts and 1.2 % of bovine bile, respectively; of 3.5 × 1013 and 3.4 × 1013 UFC/ml for 38 and 45 °C, respectively. The HPLC determined the peptides VAR-TIR-VAR and lactic acid (83.11 %. The fermentation kinetics determined the exponential phase at 14:24 h with a value of 77 × 1010 UFC/ ml, pH values of 4.284, 2.33 mg/ml sugar, 1.44 mg/ml protein and acidity of 0.79 %. It was found that S. aureus and S. epidermidis were sensitive to all antibiotics. The pathogenic bacteria were resistant to the lactic strain, but S. epidermidis was sensitive to the supernatant of L. lactis. The conclusion is that Lactobacillus lactis showed adequate growth capacity, good fermentation parameters and inhibitory effect in strains of S. aureus and S. epidermidis in in vitro conditions.

  14. 34 CFR 668.173 - Refund reserve standards.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 3 2010-07-01 2010-07-01 false Refund reserve standards. 668.173 Section 668.173 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY EDUCATION, DEPARTMENT OF EDUCATION STUDENT ASSISTANCE GENERAL PROVISIONS Financial Responsibility § 668.173...

  15. H-mode transition physics close to DN on MAST and its applications to other tokamaks

    International Nuclear Information System (INIS)

    Meyer, H.

    2004-01-01

    Full text: ELMy H-mode is the base-line operating scenario for the next step fusion device ITER. To improve active and passive pedestal control a deeper understanding of H- mode physics is desirable. MAST contributes towards this understanding with good edge diagnostics, and by accessing extreme parameter regimes. The first inter-machine comparisons with respect to the influence of the magnetic topology on the power threshold with ASDEX-Upgrade and NSTX reveal a reduction of the power threshold in true double null (C-DN) configuration opening new operation regimes in both devices. The 30% reduction in threshold power close to C-DN observed on ASDEX-Upgrade, though significant, is less than the factor of two or more observed in both large spherical tokamaks, MAST and NSTX. This points towards the importance of field line curvature for this effect. The power thresholds measured in C-DN on MAST and NSTX are very similar. Despite this strong effect on the power threshold, changes in most edge parameters in L-mode due to the different magnetic configurations are small. However, significant changes are seen in the toroidal impurity flow velocity, related to the radial electric field, and in the scrape-off-layer temperature decay length at the high field side. The statistical comparison of MAST data with various H-mode theories suggests that different instabilities need to be stabilised at different spatial positions in the region where the pedestal forms to access H-mode. Pedestal temperatures observed on MAST are two to five times lower than in MAST equivalent discharges at ASDEX-Upgrade. However, the pedestal densities are similar. The differences in L-mode are less significant. The usual DN operating regime with co current NBI in MAST has been extended to include single null (SN) configurations, to provide more direct comparisons with conventional tokamaks. The plasma edge in SN on MAST is more stable to ELMs and the typical type-III ELMs, often observed in C-DN, are

  16. Nisin production of Lactococcus lactis N8 with hemin-stimulated cell respiration in fed-batch fermentation system.

    Science.gov (United States)

    Kördikanlıoğlu, Burcu; Şimşek, Ömer; Saris, Per E J

    2015-01-01

    In this study, nisin production of Lactococcus lactis N8 was optimized by independent variables of glucose, hemin and oxygen concentrations in fed-batch fermentation in which respiration of cells was stimulated with hemin. Response surface model was able to explain the changes of the nisin production of L. lactis N8 in fed-batch fermentation system with high fidelity (R(2) 98%) and insignificant lack of fit. Accordingly, the equation developed indicated the optimum parameters for glucose, hemin, and dissolved oxygen were 8 g L(-1) h(-1) , 3 μg mL(-1) and 40%, respectively. While 1711 IU mL(-1) nisin was produced by L. lactis N8 in control fed-batch fermentation, 5410 IU mL(-1) nisin production was achieved within the relevant optimum parameters where the respiration of cell was stimulated with hemin. Accordingly, nisin production was enhanced 3.1 fold in fed-batch fermentation using hemin. In conclusion the nisin production of L. lactis N8 was enhanced extensively as a result of increasing the biomass by stimulating the cell respiration with adding the hemin in the fed-batch fermentation. © 2015 American Institute of Chemical Engineers.

  17. Flavins contained in yeast extract are exploited for anodic electron transfer by Lactococcus lactis.

    Science.gov (United States)

    Masuda, Masaki; Freguia, Stefano; Wang, Yung-Fu; Tsujimura, Seiya; Kano, Kenji

    2010-06-01

    Cyclic voltammograms of yeast extract-containing medium exhibit a clear redox peak around -0.4V vs. Ag|AgCl. Fermentative bacterium Lactococcus lactis was hereby shown to exploit this redox compound for extracellular electron transfer towards a graphite anode using glucose as an electron donor. High performance liquid chromatography revealed that this may be a flavin-type compound. The ability of L. lactis to exploit exogenous flavins for anodic glucose oxidation was confirmed by tests where flavin-type compounds were supplied to the bacterium in well defined media. Based on its mid-point potential, riboflavin can be regarded as a near-optimal mediator for microbially catalyzed anodic electron transfer. Riboflavin derivative flavin mononucleotide (FMN) was also exploited by L. lactis as a redox shuttle, unlike flavin adenine dinucleotide (FAD), possibly due to the absence of a specific transporter for the latter. The use of yeast extract in microbial fuel cell media is herein discouraged based on the related unwanted artificial addition of redox mediators which may distort experimental results. Copyright 2009 Elsevier B.V. All rights reserved.

  18. Crystallization and preliminary X-ray crystallographic analysis of β-galactosidase from Kluyveromyces lactis

    International Nuclear Information System (INIS)

    Pereira-Rodríguez, Ángel; Fernández-Leiro, Rafael; González Siso, M. Isabel; Cerdán, M. Esperanza; Becerra, Manuel; Sanz-Aparicio, Julia

    2010-01-01

    β-Galactosidase from K. lactis has been expressed in S. cerevisiae, purified by affinity chromatography and crystallized in its native form. β-Galactosidase from Kluyveromyces lactis catalyses the hydrolysis of the β-galactosidic linkage in lactose. Owing to its many industrial applications, the biotechnological potential of this enzyme is substantial. This protein has been expressed in yeast and purified for crystallization trials. However, optimization of the best crystallization conditions yielded crystals with poor diffraction quality that precluded further structural studies. Finally, the crystal quality was improved using the streak-seeding technique and a complete diffraction data set was collected at 2.8 Å resolution

  19. Coculture-inducible bacteriocin biosynthesis of different probiotic strains by dairy starter culture Lactococcus lactis

    Directory of Open Access Journals (Sweden)

    Blaženka Kos

    2011-12-01

    Full Text Available Bacteriocins produced by probiotic strains effectively contribute to colonization ability of probiotic strains and facilitate their establishment in the competitive gut environment and also protect the gut from gastrointestinal pathogens. Moreover, bacteriocins have received considerable attention due to their potential application as biopreservatives, especially in dairy industry. Hence, the objective of this research was to investigate antimicrobial activity of probiotic strains Lactobacillus helveticus M92, Lactobacillus plantarum L4 and Enterococcus faecium L3, with special focus on their bacteriocinogenic activity directed towards representatives of the same or related bacterial species, and towards distant microorganisms including potential food contaminants or causative agents of gut infections. In order to induce bacteriocin production, probiotic cells were cocultivated with Lactococcus lactis subsp. lactis LMG 9450, one of the most important starter cultures in cheese production. The presence of bacteriocin coding genes was investigated by PCR amplification with sequence-specific primers for helveticin and was confirmed for probiotic strain L. helveticus M92. All examined probiotic strains have shown bacteriocinogenic activity against Staphylococcus aureus 3048, Staphylococcus aureus K-144, Escherichia coli 3014, Salmonella enterica serovar Typhimurium FP1, Bacillus subtilis ATCC 6633, Bacillus cereus TM2, which is an important functional treat of probiotic strains significant in competitive exclusion mechanism which provides selective advantage of probiotic strains against undesirable microorganisms in gastrointestinal tract of the host. According to obtained results, living cells of starter culture Lc. lactis subsp. lactis LMG 9450 induced bacteriocin production by examined probiotic strains but starter culture itself was not sensitive to bacteriocin activity.

  20. Development and Diversity of Lactococcus lactis and Leuconostoc Bacteriophages in Dairies Using Undefined Mesophilic DL-Starter Cultures

    DEFF Research Database (Denmark)

    Muhammed, Musemma Kedir

    complete loss of fermentation. Dairy phages have for long time been studied using traditional culture-dependent methods but not using metagenomic approaches. Part of this project was devoted to develop a method for dairy metavirome extraction and analysis. Several whey mixtures derived by defined......Bacteriophages (phages) attacking strains of Lactococcus (Lc.) lactis and Leuconostoc species, used as starter cultures in mesophilic dairy productions, produce huge problems through waste of ingredients, increased processing time, reduced product quality, consistency and safety, and occasionally...... in dairies using undefined starters and of mostly Lc. lactis c2 phages in dairies using defined cultures. Certain evidence indicating possible co-induction of temperate P335 phages and smaller Lc. lactis satellite phages was obtained. Also addressed was the issue of accurate and simultaneous quantification...

  1. 21 CFR 173.355 - Dichlorodifluoromethane.

    Science.gov (United States)

    2010-04-01

    ... with good manufacturing practice, as a direct-contact freezing agent for foods. (c) To assure safe use... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Dichlorodifluoromethane. 173.355 Section 173.355 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD...

  2. Nisin Z produced by Lactococcus lactis from bullfrog hatchery is active against Citrobacter freundii, a red-leg syndrome related pathogen.

    Science.gov (United States)

    Quintana, Gabriel; Niederle, Maria V; Minahk, Carlos J; Picariello, Gianluca; Nader-Macías, María E F; Pasteris, Sergio E

    2017-09-27

    Lactococcus lactis subsp. lactis CRL 1584 isolated from a bullfrog hatchery produces a bacteriocin that inhibits both indigenous Citrobacter freundii (a Red-Leg Syndrome related pathogen) and Lactobacillus plantarum, and Listeria monocytogenes as well. Considering that probiotics requires high cell densities and/or bacteriocin concentrations, the effect of the temperature on L. lactis growth and bacteriocin production was evaluated to find the optimal conditions. Thus, the growth rate was maximal at 36 °C, whereas the highest biomass and bacteriocin activity was achieved between 20 and 30 °C and 20-25 °C, respectively. The bacteriocin synthesis was closely growth associated reaching the maximal values at the end of the exponential phase. Since bacteriocins co-production has been evidenced in bacterial genera, a purification of the bacteriocin/s from L. lactis culture supernatants was carried out. The active fraction was purified by cationic-exchange chromatography and then, a RP-HPLC was carried out. The purified sample was a peptide with a 3353.05 Da, a molecular mass that matches nisin Z, which turned out to be the only bacteriocin produced by L. lactis CRL 1584. Nisin Z showed bactericidal effect on C. freundii and L. monocytogenes, which increased in the presence L-lactic acid + H 2 O 2 . This is the first report on nisin Z production by L. lactis from a bullfrog hatchery that resulted active on a Gram-negative pathogen. This peptide has potential probiotic for raniculture and as food biopreservative for bullfrog meat.

  3. Protective Effects of Bifidobacterium on Intestinal Barrier Function in LPS-Induced Enterocyte Barrier Injury of Caco-2 Monolayers and in a Rat NEC Model.

    Science.gov (United States)

    Ling, Xiang; Linglong, Peng; Weixia, Du; Hong, Wei

    2016-01-01

    Zonulin protein is a newly discovered modulator which modulates the permeability of the intestinal epithelial barrier by disassembling intercellular tight junctions (TJ). Disruption of TJ is associated with neonatal necrotizing enterocolitis (NEC). It has been shown bifidobacterium could protect the intestinal barrier function and prophylactical administration of bifidobacterium has beneficial effects in NEC patients and animals. However, it is still unknown whether the zonulin is involved in the gut barrier dysfunction of NEC, and the protective mechanisms of bifidobacterium on intestinal barrier function are also not well understood. The present study aims to investigate the effects of bifidobacterium on intestinal barrier function, zonulin regulation, and TJ integrity both in LPS-induced enterocyte barrier injury of Caco-2 monolayers and in a rat NEC model. Our results showed bifidobacterium markedly attenuated the decrease in transepithelial electrical resistance and the increase in paracellular permeability in the Caco-2 monolayers treated with LPS (P zonulin release (P zonulin (P zonulin protein release and improvement of intestinal TJ integrity.

  4. 29 CFR 1915.173 - Drums and containers.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Drums and containers. 1915.173 Section 1915.173 Labor... Vessels, Drums and Containers, Other Than Ship's Equipment § 1915.173 Drums and containers. (a) Shipping drums and containers shall not be pressurized to remove their contents. (b) A temporarily assembled...

  5. 49 CFR 173.3 - Packaging and exceptions.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Packaging and exceptions. 173.3 Section 173.3... SHIPMENTS AND PACKAGINGS General § 173.3 Packaging and exceptions. (a) The packaging of hazardous materials.... standard packaging must be open to inspection by a representative of the Department. (b) The regulations...

  6. 13 CFR 120.173 - Lead-based paint.

    Science.gov (United States)

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Lead-based paint. 120.173 Section 120.173 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION BUSINESS LOANS Policies Applying to All Business Loans Requirements Imposed Under Other Laws and Orders § 120.173 Lead-based paint. If...

  7. 21 CFR 173.275 - Hydrogenated sperm oil.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Hydrogenated sperm oil. 173.275 Section 173.275... CONSUMPTION Solvents, Lubricants, Release Agents and Related Substances § 173.275 Hydrogenated sperm oil. The food additive hydrogenated sperm oil may be safely used in accordance with the following prescribed...

  8. 25 CFR 173.2 - Project engineer's authority.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Project engineer's authority. 173.2 Section 173.2 Indians... LANDS WITHDRAWN OR ACQUIRED IN CONNECTION WITH INDIAN IRRIGATION PROJECTS § 173.2 Project engineer's authority. The project engineer is the official charged with the responsibility for the enforcement of this...

  9. 21 CFR 184.1388 - Lactase enzyme preparation from Kluyveromyces lactis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Lactase enzyme preparation from Kluyveromyces... GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS § 184.1388 Lactase enzyme preparation from Kluyveromyces lactis. (a) This enzyme preparation is derived from the nonpathogenic...

  10. Versatile Cas9-driven subpopulation selection toolbox for Lactococcus lactis

    NARCIS (Netherlands)

    Els, van der Simon; James, Jennelle K.; Kleerebezem, Michiel; Bron, Peter A.

    2018-01-01

    CRISPR-Cas9 technology has been exploited for the removal or replacement of genetic elements in a wide range of prokaryotes and eukaryotes. Here, we describe the extension of the Cas9 application toolbox to the industrially important dairy species Lactococcus lactis. The Cas9 expression vector

  11. Construction of an expression vector for Lactococcus lactis based on ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-11-02

    Nov 2, 2009 ... Tamez-Guerra RS, Oliveira SC, Saucedo-Cardenas O, de Oca-Luna. RM, Le Loir Y (2003). Intranasal immunization with recombinant. Lactococcus lactis secreting murine interleukin-12 enhances antigen- specific Th1 cytokine production. Infection Immunity, 71: 1887-1896. De Vos WM, Simons G (1994).

  12. Lipid-protein interactions. The leucine transport system of Lactococcus lactis.

    NARCIS (Netherlands)

    Veld, Geertruida Elisabeth in 't

    1992-01-01

    In summary, it is concluded, that a functionally reconstituted leucine transport system of L. lactis is affected by bilayer features in the following order of importance: lipid headgroup (H+-bonding) › acyl chain carbon number (thickness) › cholesterol (fluidity) › acyl chain unsaturation (indirect

  13. Heterologous protein secretion in Lactococcus lactis: a novel antigen delivery system

    Directory of Open Access Journals (Sweden)

    Langella P.

    1999-01-01

    Full Text Available Lactic acid bacteria (LAB are Gram-positive bacteria and are generally regarded as safe (GRAS organisms. Therefore, LAB could be used for heterologous protein secretion and they are good potential candidates as antigen delivery vehicles. To develop such live vaccines, a better control of protein secretion is required. We developed an efficient secretion system in the model LAB, Lactococcus lactis. Staphylococcal nuclease (Nuc was used as the reporter protein. We first observed that the quantity of secreted Nuc correlated with the copy number of the cloning vector. The nuc gene was cloned on a high-copy number cloning vector and no perturbation of the metabolism of the secreting strain was observed. Replacement of nuc native promoter by a strong lactococcal one led to a significant increase of nuc expression. Secretion efficiency (SE of Nuc in L. lactis was low, i.e., only 60% of the synthesized Nuc was secreted. Insertion of a synthetic propeptide between the signal peptide and the mature moiety of Nuc increased the SE of Nuc. On the basis of these results, we developed a secretion system and we applied it to the construction of an L. lactis strain which secretes a bovine coronavirus (BCV epitope-protein fusion (BCV-Nuc. BCV-Nuc was recognized by both anti-BCV and anti-Nuc antibodies. Secretion of this antigenic fusion is the first step towards the development of a novel antigen delivery system based on LAB-secreting strains.

  14. A Lactococcus lactis expression vector set with multiple affinity tags to facilitate isolation and direct labeling of heterologous secreted proteins

    NARCIS (Netherlands)

    Pastrana, Francisco Romero; Neef, Jolanda; van Dijl, Jan Maarten; Buist, Girbe

    The gram-positive bacterium Lactococcus lactis is a useful host for extracellular protein production. A main advantage of L. lactis over other bacterial expression systems is that lactococcal cells display low levels of autolysis and proteolysis. Previously, we developed a set of vectors for

  15. Bile salt tolerance of Lactococcus lactis is enhanced by expression of bile salt hydrolase thereby producing less bile acid in the cells.

    Science.gov (United States)

    Bi, Jie; Liu, Song; Du, Guocheng; Chen, Jian

    2016-04-01

    Changes of bile salt tolerance, morphology and amount of bile acid within cells were studied to evaluate the exact effects of bile salt hydrolase (BSH) on bile salt tolerance of microorganism. The effect of BSHs on the bile salt tolerance of Lactococcus lactis was examined by expressing two BSHs (BSH1 and BSH2). Growth of L. lactis expressing BSH1 or BSH2 was better under bile salt stress compared to wild-type L. lactis. As indicated by transmission electron microscopy, bile acids released by the action of BSH induced the formation of micelles around the membrane surface of cells subject to conjugated bile salt stress. A similar micelle containing bile acid was observed in the cytoplasm by liquid chromatography-mass spectrometry. BSH1 produced fewer bile acid micelles in the cytoplasm and achieved better cell growth of L. lactis compared to BSH2. Expression of BSH improved bile salt tolerance of L. lactis but excessive production by BSH of bile acid micelles in the cytoplasm inhibited cell growth.

  16. Um suplemento entre dois mundos : Causas e consequências da transição papel/digital do DN Jovem

    Directory of Open Access Journals (Sweden)

    Helena de Sousa Freitas

    2012-01-01

    Full Text Available The DN Jovem, a supplement that the Portuguese newspaper Diário de Notícias (DN began publishing in May 1983, quickly became a showcase for new prose writers, poets, photographers and illustrators. In June 1996, when access to the Internet didn’t even reach one percent of Portuguese homes, its contents migrated from print to online. The transition, determined by the Administration of DN within a newspaper’s restructuring, announced the death of a supplement that was, according to Portuguese writer José Jorge Letria, “the most important spot for the revelation and affirmation of new literary values” in democratic Portugal.

  17. Lactococcus lactis Thioredoxin Reductase Is Sensitive to Light Inactivation

    DEFF Research Database (Denmark)

    Björnberg, Olof; Viennet, Thibault; Skjoldager, Nicklas

    2015-01-01

    Thioredoxin, involved in numerous redox pathways, is maintained in the dithiol state by the nicotinamide adenine dinucleotide phosphate-dependent flavoprotein thioredoxin reductase (TrxR). Here, TrxR from Lactococcus lactis is compared with the well-characterized TrxR from Escherichia coli. The two...... enzymes belong to the same class of low-molecular weight thioredoxin reductases and display similar kcat values (∼25 s-1) with their cognate thioredoxin. Remarkably, however, the L. lactis enzyme is inactivated by visible light and furthermore reduces molecular oxygen 10 times faster than E. coli Trx......-resolution mass spectrometric analysis of heat-extracted FAD from light-damaged TrxR revealed a mass increment of 13.979 Da, relative to that of unmodified FAD, corresponding to the addition of one oxygen atom and the loss of two hydrogen atoms. Tandem mass spectrometry confined the increase in mass...

  18. 49 CFR 173.183 - Nitrocellulose base film.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Nitrocellulose base film. 173.183 Section 173.183... Nitrocellulose base film. Films, nitrocellulose base, must be packaged in packagings conforming to the... tape or paper; authorized only for not over 600 m (1969 feet) of film. [Amdt. 173-224, 55 FR 52643 Dec...

  19. 21 CFR 173.55 - Polyvinylpyrrolidone.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyvinylpyrrolidone. 173.55 Section 173.55 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... a residual level not to exceed 40 parts per million. Wine As a clarifying agent, at a residual level...

  20. Alternatives for biosurfactants and bacteriocins extraction from Lactococcus lactis cultures produced under different pH conditions.

    Science.gov (United States)

    Rodríguez, N; Salgado, J M; Cortés, S; Domínguez, J M

    2010-08-01

    Study of the potential of Lactococcus lactis CECT-4434 as a biosurfactants and nisin (the only bacteriocin allowed to be used in the food industry) producer for industrial applications, exploiting the possibility of recovering separately both metabolites, taking into account that L. lactis is an interesting micro-organism with several applications in the food industry because it is recognized as GRAS. The results showed the ability of this strain to produce cell-bound biosurfactants, under controlled pH, and cell-bound biosurfactants and bacteriocins, when pH was not controlled. Three extraction procedures were designed to separately recover these substances. The strain L. lactis CECT-4434 showed to be a cell-bound biosurfactants and bacterocins producer when fermentations were carried out under uncontrolled pH. Both products can be recovered separately. Development of a convenient tool for the extraction of cell-bound biosurfactants and bacteriocins from the fermentation broth.

  1. The effect of co-administration of lactobacillus probiotics and bifidobacterium on spatial memory and learning in diabetic rats

    Directory of Open Access Journals (Sweden)

    Davari S

    2012-12-01

    Full Text Available Background: Diabetes mellitus affects numerous intracellular metabolic processes, which are reflected by changes in the concentration of some plasma constituents. Particularly, the disease may indirectly undermine some functions of the nervous system including learning and memory through altering oxidative stress status. On the other hand, probiotics can enhance the antioxidant capacity. This study was designed to evaluate the effects of probiotics on spatial memory, maze learning and indices of oxidative stress in diabetic rats.Methods: In this experimental study, 40 male Wistar rats were randomly allocated to 4 groups (n=10 for each: Control (CO, Control probiotic (CP, Control diabetic (DC, and Diabetic probiotic (DP. The probiotic supplement, including Lactobacillus acidophilus, Lactobacillus fermentum, Bifidobacterium lactis (334 mg of each with a CFU of ~1010, was administered through drinking water every 12 hours for 8 weeks. Using morris water maze (MWM, spatial learning and memory were evaluated. Serum insulin and oxidative stress indices, including superoxide dismutase (SOD and 8-hydroxy-2'-deoxyguanosine (8-OHdG, were measured by standard laboratory kits.Results: Oral administration of probiotics improved impairment of spatial learning (P=0.008 and consolidated memory (P=0.01 in the rats. Moreover, probiotic treatment increased serum insulin (P<0.0001 and serum superoxide dismutase activity (P=0.007 while it decreased their blood glucose (P=0.006 and 8-OHdG (P<0.0001.Conclusion: Probiotic supplementation reversed the serum concentrations of insulin and glucose along with an increase in antioxidant capacity in diabetic rats. It also improved spatial learning and memory in the animals. Relevancy of the metabolic changes and behavioral functions need to be further studied.

  2. The properties of Kluyveromyces lactis for the production of D ...

    African Journals Online (AJOL)

    Production of D-arabitol from lactose by Kluyveromyces lactis NBRC 1903 was investigated to make a solution for utilization of whey. It turned out that initial concentration of yeast extract, working volume and initial cell mass concentration are important factors in D-arabitol production from lactose by this strain.

  3. Glycosulfatase-Encoding Gene Cluster in Bifidobacterium breve UCC2003.

    Science.gov (United States)

    Egan, Muireann; Jiang, Hao; O'Connell Motherway, Mary; Oscarson, Stefan; van Sinderen, Douwe

    2016-11-15

    Bifidobacteria constitute a specific group of commensal bacteria typically found in the gastrointestinal tract (GIT) of humans and other mammals. Bifidobacterium breve strains are numerically prevalent among the gut microbiota of many healthy breastfed infants. In the present study, we investigated glycosulfatase activity in a bacterial isolate from a nursling stool sample, B. breve UCC2003. Two putative sulfatases were identified on the genome of B. breve UCC2003. The sulfated monosaccharide N-acetylglucosamine-6-sulfate (GlcNAc-6-S) was shown to support the growth of B. breve UCC2003, while N-acetylglucosamine-3-sulfate, N-acetylgalactosamine-3-sulfate, and N-acetylgalactosamine-6-sulfate did not support appreciable growth. By using a combination of transcriptomic and functional genomic approaches, a gene cluster designated ats2 was shown to be specifically required for GlcNAc-6-S metabolism. Transcription of the ats2 cluster is regulated by a repressor open reading frame kinase (ROK) family transcriptional repressor. This study represents the first description of glycosulfatase activity within the Bifidobacterium genus. Bifidobacteria are saccharolytic organisms naturally found in the digestive tract of mammals and insects. Bifidobacterium breve strains utilize a variety of plant- and host-derived carbohydrates that allow them to be present as prominent members of the infant gut microbiota as well as being present in the gastrointestinal tract of adults. In this study, we introduce a previously unexplored area of carbohydrate metabolism in bifidobacteria, namely, the metabolism of sulfated carbohydrates. B. breve UCC2003 was shown to metabolize N-acetylglucosamine-6-sulfate (GlcNAc-6-S) through one of two sulfatase-encoding gene clusters identified on its genome. GlcNAc-6-S can be found in terminal or branched positions of mucin oligosaccharides, the glycoprotein component of the mucous layer that covers the digestive tract. The results of this study provide

  4. Purification and characterization of two new cell-bound bioactive compounds produced by wild Lactococcus lactis strain.

    Science.gov (United States)

    Saraiva, Margarete Alice Fontes; Brede, Dag Anders; Nes, Ingolf Figved; Baracat-Pereira, Maria Cristina; de Queiroz, Marisa Vieira; de Moraes, Célia Alencar

    2017-07-03

    Novel compounds and innovative methods are required considering that antibiotic resistance has reached a crisis point. In the study, two cell-bound antimicrobial compounds produced by Lactococcus lactis ID1.5 were isolated and partially characterized. Following purification by cationic exchange and a solid-phase C18 column, antimicrobial activity was recovered after three runs of RPC using 60% (v/v) and 100% (v/v) of 2-propanol for elution, suggesting that more than one antimicrobial compound were produced by L. lactis ID1.5, which were in this study called compounds AI and AII. The mass spectrum of AI and AII showed major intensity ions at m/z 1070.05 and 955.9 Da, respectively. The compound AI showed a spectrum of antimicrobial activity mainly against L. lactis species, while the organisms most sensitive to compound AII were Bacillus subtilis, Listeria innocua, Streptococcus pneumoniae and Pseudomonas aeruginosa. The antimicrobial activity of both compounds was suppressed by treatment with Tween 80. Nevertheless, both compounds showed high stability to heat and proteases treatments. The isolated compounds, AI and AII, showed distinct properties from other antimicrobial substances already reported as produced by L. lactis, and have a significant inhibitory effect against two clinically important respiratory pathogens. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. Immunization with r-Lactococcus lactis expressing outer membrane protein A of Shigella dysenteriae type-1: evaluation of oral and intranasal route of administration.

    Science.gov (United States)

    Yagnik, B; Sharma, D; Padh, H; Desai, P

    2017-02-01

    To evaluate the comparative immunogenic potential of food grade Lactococcus lactis expressing outer membrane protein A (OmpA) of Shigella dysenteriae type-1 (SD-1) when administered either orally or intranasally. OmpA of SD-1 was cloned and expressed first in Escherichia coli and then in L. lactis. Presence of recombinant gene was confirmed by restriction enzyme digestion and immunoblot analysis. Using immobilized metal affinity chromatography, OmpA was purified from recombinant E. coliBL21 (DE3) and subcutaneously administered in BALB/c mice. Detection of OmpA-specific IgG antibodies by enzyme-linked immunosorbent assay (ELISA) confirmed the immunogenicity of OmpA. In order to establish r-L. lactis as a mucosal delivery vehicle, it was administered orally and nasally in BALB/c mice. Serum IgG and faecal IgA were assessed through ELISA to compare the relative potential of immunization routes and immunogenic potential of r-L. lactis. Immunization via the oral route proved superior to intranasal exposure. Recombinant L. lactis expressing OmpA of SD-1 was found to be immunogenic. Oral administration of r-L. lactis elicited higher systemic and mucosal immune response when compared with the nasal route. Using food grade recombinant L. lactis has implications in the development of a prophylactic against multidrug-resistant Shigella, which can be used as a prospective vaccine candidate. Evaluating mucosal routes of immunization demonstrated that the oral route of administration elicited better immune response against OmpA of Shigella. © 2016 The Society for Applied Microbiology.

  6. Structural rearrangements of sucrose phosphorylase from Bifidobacterium adolescentis during sucrose conversion

    DEFF Research Database (Denmark)

    Mirza, Osman; Henriksen, Lars Skov; Sprogøe, Desiree

    2006-01-01

    The reaction mechanism of sucrose phosphorylase from Bifidobacterium adolescentis (BiSP) was studied by site-directed mutagenesis and x-ray crystallography. An inactive mutant of BiSP (E232Q) was co-crystallized with sucrose. The structure revealed a substrate-binding mode comparable with that se...

  7. Yeast Kluyveromyces lactis as host for expression of the bacterial lipase: cloning and adaptation of the new lipase gene from Serratia sp.

    Science.gov (United States)

    Šiekštelė, Rimantas; Veteikytė, Aušra; Tvaska, Bronius; Matijošytė, Inga

    2015-10-01

    Many microbial lipases have been successfully expressed in yeasts, but not in industrially attractive Kluyveromyces lactis, which among other benefits can be cultivated on a medium supplemented with whey--cheap and easily available industrial waste. A new bacterial lipase from Serratia sp. was isolated and for the first time expressed into the yeast Kluyveromyces lactis by heterologous protein expression system based on a strong promoter of Kluyveromyces marxianus triosephosphate isomerase gene and signal peptide of Kluyveromyces marxianus endopolygalacturonase gene. In addition, the bacterial lipase gene was synthesized de novo by taking into account a codon usage bias optimal for K. lactis and was expressed into the yeast K. lactis also. Both resulting strains were characterized by high output level of the target protein secreted extracellularly. Secreted lipases were characterized for activity and stability.

  8. Complete sequences of four plasmids of Lactococcus lactis subsp cremoris SK11 reveal extensive adaptation to the dairy environment

    NARCIS (Netherlands)

    Siezen, R.J.; Renckens, B.; Swam, van I.; Peters, S.; Kranenburg, van R.; Kleerebezem, M.; Vos, de W.M.

    2005-01-01

    Lactococcus lactis strains are known to carry plasmids encoding industrially important traits. L. lactis subsp. cremoris SK11 is widely used by the dairy industry in cheese making. Its complete plasmid complement was sequenced and found to contain the plasmids pSK11A (10,372 bp), pSK11B (13,332 bp),

  9. Engineering signal peptides for enhanced protein secretion from Lactococcus lactis.

    Science.gov (United States)

    Ng, Daphne T W; Sarkar, Casim A

    2013-01-01

    Lactococcus lactis is an attractive vehicle for biotechnological production of proteins and clinical delivery of therapeutics. In many such applications using this host, it is desirable to maximize secretion of recombinant proteins into the extracellular space, which is typically achieved by using the native signal peptide from a major secreted lactococcal protein, Usp45. In order to further increase protein secretion from L. lactis, inherent limitations of the Usp45 signal peptide (Usp45sp) must be elucidated. Here, we performed extensive mutagenesis on Usp45sp to probe the effects of both the mRNA sequence (silent mutations) and the peptide sequence (amino acid substitutions) on secretion. We screened signal peptides based on their resulting secretion levels of Staphylococcus aureus nuclease and further evaluated them for secretion of Bacillus subtilis α-amylase. Silent mutations alone gave an increase of up to 16% in the secretion of α-amylase through a mechanism consistent with relaxed mRNA folding around the ribosome binding site and enhanced translation. Targeted amino acid mutagenesis in Usp45sp, combined with additional silent mutations from the best clone in the initial screen, yielded an increase of up to 51% in maximum secretion of α-amylase while maintaining secretion at lower induction levels. The best sequence from our screen preserves the tripartite structure of the native signal peptide but increases the positive charge of the n-region. Our study presents the first example of an engineered L. lactis signal peptide with a higher secretion yield than Usp45sp and, more generally, provides strategies for further enhancing protein secretion in bacterial hosts.

  10. Host lysozyme-mediated lysis of Lactococcus lactis facilitates delivery of colitis-attenuating superoxide dismutase to inflamed colons

    Science.gov (United States)

    Ballal, Sonia A.; Veiga, Patrick; Fenn, Kathrin; Michaud, Monia; Kim, Jason H.; Gallini, Carey Ann; Glickman, Jonathan N.; Quéré, Gaëlle; Garault, Peggy; Béal, Chloé; Derrien, Muriel; Courtin, Pascal; Kulakauskas, Saulius; Chapot-Chartier, Marie-Pierre; van Hylckama Vlieg, Johan; Garrett, Wendy S.

    2015-01-01

    Beneficial microbes that target molecules and pathways, such as oxidative stress, which can negatively affect both host and microbiota, may hold promise as an inflammatory bowel disease therapy. Prior work showed that a five-strain fermented milk product (FMP) improved colitis in T-bet−/− Rag2−/− mice. By varying the number of strains used in the FMP, we found that Lactococcus lactis I-1631 was sufficient to ameliorate colitis. Using comparative genomic analyses, we identified genes unique to L. lactis I-1631 involved in oxygen respiration. Respiration of oxygen results in reactive oxygen species (ROS) generation. Also, ROS are produced at high levels during intestinal inflammation and cause tissue damage. L. lactis I-1631 possesses genes encoding enzymes that detoxify ROS, such as superoxide dismutase (SodA). Thus, we hypothesized that lactococcal SodA played a role in attenuating colitis. Inactivation of the sodA gene abolished L. lactis I-1631’s beneficial effect in the T-bet−/− Rag2−/− model. Similar effects were obtained in two additional colonic inflammation models, Il10−/− mice and dextran sulfate sodium-treated mice. Efforts to understand how a lipophobic superoxide anion (O2−) can be detoxified by cytoplasmic lactoccocal SodA led to the finding that host antimicrobial-mediated lysis is a prerequisite for SodA release and SodA’s extracytoplasmic O2− scavenging. L. lactis I-1631 may represent a promising vehicle to deliver antioxidant, colitis-attenuating SodA to the inflamed intestinal mucosa, and host antimicrobials may play a critical role in mediating SodA’s bioaccessibility. PMID:26056274

  11. Possible measurements of the spin one observables in elastic dN, dd collisions at the NICA deuteron beams

    International Nuclear Information System (INIS)

    Sharov, V I

    2016-01-01

    The report shows the possibilities of studying the spin one observables in the elastic dN and dd interactions at the NICA collider of the VBLHEP JINR. The use of the colliding deuteron beams would allow us to carry out the measurements of the differential cross sections I 0 (dN, dd) of the elastic scattering of unpolarized deuterons and the differential cross sections I pol (dN,dd) and the vector A y (Ed,θ) and tensor A yy (Ed,θ) and A xx (E d .θ) analyzing powers in elastic collisions of the vector and tensor polarized deuterons. The planned luminosity of the colliding polarized deuteron beams will provide sufficiently high elastic events counting rate. The use of the colliding beams of the polarized deuterons for the spin one >dN and dd observables research has a number of significant advantages in comparison with the experiments with the “fixed” target. The angular acceptance of the collider detector covers the full solid angle 4π radians while the wide ranges of the energies of the dN, dd interactions and the 4-momentum transfer squared are available. (paper)

  12. Identification and characterization of tetracycline resistance in Lactococcus lactis isolated from Polish raw milk and fermented artisanal products.

    Science.gov (United States)

    Zycka-Krzesinska, Joanna; Boguslawska, Joanna; Aleksandrzak-Piekarczyk, Tamara; Jopek, Jakub; Bardowski, Jacek K

    2015-10-15

    To assess the occurrence of antibiotic-resistant Lactic Acid Bacteria (LAB) in Polish raw milk and fermented artisanal products, a collection comprising 500 isolates from these products was screened. Among these isolates, six strains (IBB28, IBB160, IBB161, IBB224, IBB477 and IBB487) resistant to tetracycline were identified. The strains showing atypical tetracycline resistance were classified as Lactococcus lactis: three of them were identified as L. lactis subsp. cremoris (IBB224, IBB477 and IBB487) and the other three (IBB28, IBB160, IBB161) were identified as L. lactis subsp. lactis. The mechanism involving Ribosomal Protection Proteins (RPP) was identified as responsible for tetracycline resistance. Three of the tested strains (IBB28, IBB160 and IBB224) had genes encoding the TetS protein, whereas the remaining three (IBB161, IBB477 and IBB487) expressed TetM. The results also demonstrated that the genes encoding these proteins were located on genetic mobile elements. The tet(S) gene was found to be located on plasmids, whereas tet(M) was found within the Tn916 transposon. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Časopis "Módní svět" a "Lada" v kulturním kontextu

    OpenAIRE

    Šrolová, Kristýna

    2010-01-01

    The thesis discusses tbe fashion magazine Módní svět (Fashion World) and its enclosure Lada, which it implants into their cultural and historica1 context. The magazine Módní svět (Fashion World) was puhli,hed from 1875 to 1935 and thi, a1,o deline, lhe time circmnscription of tbe themes in tbe thesis. It contextua11y deals with tbe women society during tbe tum of 19th to 20th century, with women's emancipatory movement, with tbe beginning of publishing of rn.agazines for women and fashion mag...

  14. Analysis of infant isolates of Bifidobacterium breve by comparative genome hybridization indicates the existence of new subspecies with marked infant specificity

    NARCIS (Netherlands)

    Boesten, R.; Schuren, F.; Wind, R.D.; Knol, J.; Vos, W.M. de

    2011-01-01

    A total of 20 Bifidobacterium strains were isolated from fecal samples of 4 breast- and bottle-fed infants and all were characterized as Bifidobacterium breve based on 16S rRNA gene sequence and metabolic analysis. These isolates were further characterized and compared to the type strains of B.

  15. Construction of a recombinant Lactococcus lactis strain expressing a fusion protein of Omp22 and HpaA from Helicobacter pylori for oral vaccine development.

    Science.gov (United States)

    Zhang, Rongguang; Duan, Guangcai; Shi, Qingfeng; Chen, Shuaiyin; Fan, Qingtang; Sun, Nan; Xi, Yuanlin

    2016-11-01

    To develop orally administrated anti-Helicobacter pylori vaccination, a Lactococcus lactis strain was genetically constructed for fusion expression of H. pylori protective antigens HpaA and Omp22. The fusion gene of omp22 and hpaA with an adapter encoding three glycines was cloned from a plasmid pMAL-c2x-omp22-hpaA into Escherichia coli MC1061 and L. lactis NZ3900 successively using a shutter vector pNZ8110. Expression of the fusion gene in L. lactis was induced with nisin resulting in production of proteins with molecular weights of 50 and 28 kDa. Both of them were immunoreactive with mouse anti-H. pylori sera as determined via western blotting. Oral vaccination of BALB/c mice using the L. lactis strain carrying pNZ8110-omp22-hpaA elicited significant systematic humoral immune response (P lactis with immunogenicity. This is a considerable step towards H. pylori vaccines.

  16. The properties of Kluyveromyces lactis for the production of D ...

    African Journals Online (AJOL)

    USER

    2010-08-02

    Aug 2, 2010 ... Production of D-arabitol from lactose by Kluyveromyces lactis NBRC 1903 was investigated to make a solution for ... lactose and are characterized by high biological oxygen demand ... to calculate cell mass concentration (X). One unit of .... cultures, time required for the complete conversion of lactose in ...

  17. Protein dynamics associated with failed and rescued learning in the Ts65Dn mouse model of Down syndrome.

    Directory of Open Access Journals (Sweden)

    Md Mahiuddin Ahmed

    Full Text Available Down syndrome (DS is caused by an extra copy of human chromosome 21 (Hsa21. Although it is the most common genetic cause of intellectual disability (ID, there are, as yet, no effective pharmacotherapies. The Ts65Dn mouse model of DS is trisomic for orthologs of ∼55% of Hsa21 classical protein coding genes. These mice display many features relevant to those seen in DS, including deficits in learning and memory (L/M tasks requiring a functional hippocampus. Recently, the N-methyl-D-aspartate (NMDA receptor antagonist, memantine, was shown to rescue performance of the Ts65Dn in several L/M tasks. These studies, however, have not been accompanied by molecular analyses. In previous work, we described changes in protein expression induced in hippocampus and cortex in control mice after exposure to context fear conditioning (CFC, with and without memantine treatment. Here, we extend this analysis to Ts65Dn mice, measuring levels of 85 proteins/protein modifications, including components of MAP kinase and MTOR pathways, and subunits of NMDA receptors, in cortex and hippocampus of Ts65Dn mice after failed learning in CFC and after learning was rescued by memantine. We show that, compared with wild type littermate controls, (i of the dynamic responses seen in control mice in normal learning, >40% also occur in Ts65Dn in failed learning or are compensated by baseline abnormalities, and thus are considered necessary but not sufficient for successful learning, and (ii treatment with memantine does not in general normalize the initial protein levels but instead induces direct and indirect responses in approximately half the proteins measured and results in normalization of the endpoint protein levels. Together, these datasets provide a first view of the complexities associated with pharmacological rescue of learning in the Ts65Dn. Extending such studies to additional drugs and mouse models of DS will aid in identifying pharmacotherapies for effective

  18. Biochemical Characteristics and Viability of Probiotic and Yogurt Bacteria in Yogurt during the Fermentation and Refrigerated Storage

    OpenAIRE

    F Sarvari; A.M. Mortazavian; M.R. Fazei

    2014-01-01

    This research aimed to investigate the viability of probiotic bacteria (Lactobacillus acidophilus LA-5 and Bifidobacterium lactis BB-12) and yogurt bacteria (Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus) in yogurt during the fermentation, immediately after fermentation and during refrigerated storage (21 d, 4˚C). Also the biochemical characteristics of milk as affected by the commercial 4-strain mixed starter culture were investigated. Storage time affected the via...

  19. Relationships between MDR proteins, bacteriocin production and proteolysis in Lactococcus lactis

    NARCIS (Netherlands)

    Gajic, Olivera

    2003-01-01

    The Gram-positive lactic acid bacterium Lactococcus lactis can harbour a wide variety of circular extrachromosomal DNA molecules, so-called plasmids. Many of the traits that make them useful for manufacturing of fermented food products (e.g. bacteriophage resistance, bacteriocin and proteinase

  20. Plasmids of Raw Milk Cheese Isolate Lactococcus lactis subsp. lactis Biovar diacetylactis DPC3901 Suggest a Plant-Based Origin for the Strain ▿ †

    Science.gov (United States)

    Fallico, Vincenzo; McAuliffe, Olivia; Fitzgerald, Gerald F.; Ross, R. Paul

    2011-01-01

    The four-plasmid complement of the raw milk cheese isolate Lactococcus lactis subsp. lactis biovar diacetylactis DPC3901 was sequenced, and some genetic features were functionally analyzed. The complete sequences of pVF18 (18,977 bp), pVF21 (21,739 bp), pVF22 (22,166 bp), and pVF50 (53,876 bp) were obtained. Each plasmid contained genes not previously described for Lactococcus, in addition to genes associated with plant-derived lactococcal strains. Most of the novel genes were found on pVF18 and encoded functions typical of bacteria associated with plants, such as activities of plant cell wall modification (orf11 and orf25). In addition, a predicted high-affinity regulated system for the uptake of cobalt was identified (orf19 to orf21 [orf19-21]), which has a single database homolog on a plant-derived Leuconostoc plasmid and whose functionality was demonstrated following curing of pVF18. pVF21 and pVF22 encode additional metal transporters, which, along with orf19-21 of pVF18, could enhance host ability to uptake growth-limiting amounts of biologically essential ions within the soil. In addition, vast regions from pVF50 and pVF21 share significant homology with the plant-derived lactococcal plasmid pGdh442, which is indicative of extensive horizontal gene transfer and recombination between these plasmids and suggests a common plant niche for their hosts. Phenotypes associated with these regions include glutamate dehydrogenase activity and Na+ and K+ transport. The presence of numerous plant-associated markers in L. lactis DPC3901 suggests a plant origin for the raw milk cheese isolate and provides for the first time the genetic basis to support the concept of the plant-milk transition for Lactococcus strains. PMID:21803914

  1. Preliminary X-ray crystallographic analysis of the d-xylulose 5-phosphate phosphoketolase from Lactococcus lactis

    International Nuclear Information System (INIS)

    Petrareanu, Georgiana; Balasu, Mihaela C.; Zander, Ulrich; Scheidig, Axel J.; Szedlacsek, Stefan E.

    2010-01-01

    The expression, purification, preliminary crystallization and crystallographic analysis of phosphoketolase from L. lactis ssp. lactis (strain IL 1403) are reported. Phosphoketolases are thiamine diphosphate-dependent enzymes which play a central role in the pentose-phosphate pathway of heterofermentative lactic acid bacteria. They belong to the family of aldehyde-lyases and in the presence of phosphate ion cleave the carbon–carbon bond of the specific substrate d-xylulose 5-phosphate (or d-fructose 6-phosphate) to give acetyl phosphate and d-glyceraldehyde 3-phosphate (or d-erythrose 4-phosphate). Structural information about phosphoketolases is particularly important in order to fully understand their mechanism as well as the steric course of phosphoketolase-catalyzed reactions. Here, the purification, preliminary crystallization and crystallographic characterization of d-xylulose 5-phosphate phosphoketolase from Lactococcus lactis are reported. The presence of thiamine diphosphate during purification was essential for the enzymatic activity of the purified protein. The crystals belonged to the monoclinic space group P2 1 . Diffraction data were obtained to a resolution of 2.2 Å

  2. Milk-derived angiotensin-I-converting enzymeinhibitory peptides generated by Lactobacillus delbrueckii subsp. lactis CRL 581

    Directory of Open Access Journals (Sweden)

    Villegas Josefina M.

    2014-01-01

    Full Text Available Several strains of Lactobacillus helveticus and Lactobacillus delbrueckii subsp. lactis were evaluated for their ability to release angiotensin-I-converting enzyme (ACE inhibitory peptides from α-casein (α-CN and β-casein (β-CN. Casein peptides resulting from L. delbrueckii subsp. lactis CRL 581-mediated hydrolysis exhibited the highest ACE-inhibitory (ACEI activities, with values of 53 and 40% for α-CN and β-CN, respectively. The casein hydrolysates were fractionated by reversedphase high pressure liquid chromatography and some of the active peptides were identified by mass spectrometry. The fraction with the highest ACEI activity arose from β-CN and contained a mixture of the β-CN f194-206 (QEPVLGPVRGPFP and f198-206 (LGPVRGPFP peptides. Furthermore, the ACEI tripeptide IPP was identified in all β-CN hydrolysates; L. delbrueckii subsp. lactis CRL 581 produced the highest amount of this peptide. The bioactive peptides released by CRL 581 strain may be used in the formulation of functional foods and nutraceuticals, representing a healthier and natural alternative for regulating blood pressure.

  3. Identification and functional characterization of the Lactococcus lactis CodY-regulated branched-chain amino acid permease BcaP (CtrA)

    NARCIS (Netherlands)

    den Hengst, CD; Groeneveld, M; Kuipers, OP; Kok, J; Hengst, Chris D. den

    Transcriptome analyses have previously revealed that a gene encoding the putative amino acid transporter CtrA (YhdG) is one of the major targets of the pleiotropic regulator CodY in Lactococcus lactis and Bacillus subtilis. The role of ctrA in L. lactis was further investigated with respect to both

  4. Metabolic Profiling of Lactococcus lactis Under Different Culture Conditions

    Directory of Open Access Journals (Sweden)

    Normah Mohd Noor

    2012-07-01

    Full Text Available Gas chromatography mass spectrometry (GC-MS and headspace gas chromatography mass spectrometry (HS/GC-MS were used to study metabolites produced by Lactococcus lactis subsp. cremoris MG1363 grown at a temperature of 30 °C with and without agitation at 150 rpm, and at 37 °C without agitation. It was observed that L. lactis produced more organic acids under agitation. Primary alcohols, aldehydes, ketones and polyols were identified as the corresponding trimethylsilyl (TMS derivatives, whereas amino acids and organic acids, including fatty acids, were detected through methyl chloroformate derivatization. HS analysis indicated that branched-chain methyl aldehydes, including 2-methylbutanal, 3-methylbutanal, and 2-methylpropanal are degdradation products of isoleucine, leucine or valine. Multivariate analysis (MVA using partial least squares discriminant analysis (PLS-DA revealed the major differences between treatments were due to changes of amino acids and fermentation products.

  5. The integrable quantum group invariant A2n-1(2) and Dn+1(2) open spin chains

    Science.gov (United States)

    Nepomechie, Rafael I.; Pimenta, Rodrigo A.; Retore, Ana L.

    2017-11-01

    A family of A2n(2) integrable open spin chains with Uq (Cn) symmetry was recently identified in arxiv:arXiv:1702.01482. We identify here in a similar way a family of A2n-1(2) integrable open spin chains with Uq (Dn) symmetry, and two families of Dn+1(2) integrable open spin chains with Uq (Bn) symmetry. We discuss the consequences of these symmetries for the degeneracies and multiplicities of the spectrum. We propose Bethe ansatz solutions for two of these models, whose completeness we check numerically for small values of n and chain length N. We find formulas for the Dynkin labels in terms of the numbers of Bethe roots of each type, which are useful for determining the corresponding degeneracies. In an appendix, we briefly consider Dn+1(2) chains with other integrable boundary conditions, which do not have quantum group symmetry.

  6. The integrable quantum group invariant A2n−1(2 and Dn+1(2 open spin chains

    Directory of Open Access Journals (Sweden)

    Rafael I. Nepomechie

    2017-11-01

    Full Text Available A family of A2n(2 integrable open spin chains with Uq(Cn symmetry was recently identified in arXiv:1702.01482. We identify here in a similar way a family of A2n−1(2 integrable open spin chains with Uq(Dn symmetry, and two families of Dn+1(2 integrable open spin chains with Uq(Bn symmetry. We discuss the consequences of these symmetries for the degeneracies and multiplicities of the spectrum. We propose Bethe ansatz solutions for two of these models, whose completeness we check numerically for small values of n and chain length N. We find formulas for the Dynkin labels in terms of the numbers of Bethe roots of each type, which are useful for determining the corresponding degeneracies. In an appendix, we briefly consider Dn+1(2 chains with other integrable boundary conditions, which do not have quantum group symmetry.

  7. Oral delivery of Bifidobacterium longum expressing α-melanocyte-stimulating hormone to combat ulcerative colitis.

    Science.gov (United States)

    Wei, Pijin; Yang, Yan; Ding, Qing; Li, Xiuying; Sun, Hanxiao; Liu, Zhaobing; Huang, Junli; Gong, Yahui

    2016-02-01

    α-Melanocyte-stimulating hormone (α-MSH) is a tridecapeptide derived from pro-opiomelanocortin that exhibits potent anti-inflammatory properties by regulating the production of inflammatory mediators. This peptide has been well established in several inflammatory models, including inflammatory bowel disease (IBD). However, its extremely short duration in vivo limits its clinical application. To address this limitation, Bifidobacterium was used here as a carrier to deliver α-MSH. We utilized α-MSH-engineered Bifidobacterium against IBD, which is closely linked to immune and intestinal microbiota dysfunction. First, we constructed a Bifidobacterium longum secreting α-MSH (B. longum-α-MSH). We then tested the recombinant α-MSH expression and determined its bioactivity in HT-29 cells. To assess its effectiveness, B. longum-α-MSH was used against an ulcerative colitis (UC) model in rats induced by dextran sulfate sodium. The data showed that α-MSH expression in B. longum-α-MSH was effective, and its biological activity was similar to the synthesized one. This UC model experiment indicated that B. longum-α-MSH successfully colonized the intestinal gut, expressed bioactive α-MSH and had a significant anti-inflammatory effect. The results demonstrate the feasibility of preventing IBD by using B. longum-α-MSH.

  8. Acid or erythromycin stress significantly improves transformation efficiency through regulating expression of DNA binding proteins in Lactococcus lactis F44.

    Science.gov (United States)

    Wang, Binbin; Zhang, Huawei; Liang, Dongmei; Hao, Panlong; Li, Yanni; Qiao, Jianjun

    2017-12-01

    Lactococcus lactis is a gram-positive bacterium used extensively in the dairy industry and food fermentation, and its biological characteristics are usually improved through genetic manipulation. However, poor transformation efficiency was the main restriction factor for the construction of engineered strains. In this study, the transformation efficiency of L. lactis F44 showed a 56.1-fold increase in acid condition (pH 5.0); meanwhile, erythromycin stress (0.04 μg/mL) promoted the transformation efficiency more significantly (76.9-fold). Notably, the transformation efficiency of F44e (L. lactis F44 harboring empty pLEB124) increased up to 149.1-fold under the synergistic stresses of acid and erythromycin. In addition, the gene expression of some DNA binding proteins (DprA, RadA, RadC, RecA, RecQ, and SsbA) changed correspondingly. Especially for radA, 25.1-fold improvement was detected when F44e was exposed to pH 5.0. Overexpression of some DNA binding proteins could improve the transformation efficiency. The results suggested that acid or erythromycin stress could improve the transformation efficiency of L. lactis through regulating gene expression of DNA binding proteins. We have proposed a simple but promising strategy for improving the transformation efficiency of L. lactis and other hard-transformed microorganisms. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  9. Dextran sulphate sodium colitis in C57BL/6J mice is alleviated by Lactococcus lactis and worsened by the neutralization of Tumor necrosis Factor α.

    Science.gov (United States)

    Berlec, Aleš; Perše, Martina; Ravnikar, Matjaž; Lunder, Mojca; Erman, Andreja; Cerar, Anton; Štrukelj, Borut

    2017-02-01

    TNFα has a well-established role in inflammatory bowel disease that affects the gastrointestinal tract and is usually manifested as Crohn's disease or ulcerative colitis. We have compared Lactococcus lactis NZ9000 displaying TNFα-binding affibody with control Lactococcus lactis and with anti-TNFα antibody infliximab for the treatment of mice with dextran sulphate sodium (DSS)-induced colitis. L. lactis NZ9000 alleviated the colitis severity one week after colitis induction with DSS, more effectively when administered in preventive fashion prior to, during and after DSS administration. TNFα-binding L. lactis was less effective than control L. lactis, particularly when TNFα-binding L. lactis was administered in preventive fashion. Similarly, an apparently detrimental effect of TNFα neutralization was observed in mice that were intraperitoneally administered anti-TNFα monoclonal antibody infliximab prior to colitis induction. The highest concentrations of tissue TNFα were observed in groups without DSS colitis that were treated either with TNFα-binding L. lactis or infliximab. To conclude, we have confirmed that L. lactis exerts a protective effect on DSS-induced colitis in mice. Contrary to expectations, but in line with some reports, the neutralization of TNFα aggravated disease symptoms in the acute phase of colitis and increased TNFα concentration in colon tissue of healthy mice. Nevertheless, we have demonstrated that oral administration of bacteria with surface displayed TNFα-binding affibody can interfere significantly with TNFα signaling and mimic the infliximab response in the given animal model of colitis. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Cloning of nis gene and Nisin purification from Lactococcus lactis ...

    African Journals Online (AJOL)

    The purified nisin by chloroform extraction was analyzed on 20% SDS-PAGE and gave sharp band at ~ 3.4 kDa. The 3 dimension structure of the purified Nisin was studied by CPHModels as pdb with chimera program. Keywords: Lactococcus lactis, nis cloning, 16S rRNA, chloroform extraction and SDS-PAGE

  11. Construction of an expression vector for Lactococcus lactis based on ...

    African Journals Online (AJOL)

    To construct an expression vector for Lactococcus lactis, the EmPMT fragment which contained the erythromycin resistance gene, P32 promoter, multiple cloning site (MCS) and terminator (T) was subcloned into the small cryptic plasmid pAR141. The resulting vector, designated as pAR1411, was found to be stably ...

  12. Intramammary infusion of a live culture of Lactococcus lactis in ewes to treat staphylococcal mastitis.

    Science.gov (United States)

    Mignacca, Sebastian Alessandro; Dore, Simone; Spuria, Liliana; Zanghì, Pietro; Amato, Benedetta; Duprè, Ilaria; Armas, Federica; Biasibetti, Elena; Camperio, Cristina; Lollai, Stefano A; Capucchio, Maria Teresa; Cannas, Eugenia Agnese; Di Marco Lo Presti, Vincenzo; Marianelli, Cinzia

    2017-12-01

    Alternatives to antibiotic therapy for mastitis in ruminants are needed. We present an evaluation, in two trials, of the efficacy of an intramammary infusion of a live culture of Lactococcus lactis for the treatment of subclinical and clinical mastitis in ewes. In total, 67 animals were enrolled: 19 lactating ewes (study 1), including healthy (N=6) and coagulase-negative staphylococci (CNS)-infected ewes (N=13); and 48 lactating ewes (study 2) with either CNS mastitis (N=32), or Staphylococcus aureus mastitis (N=16), for a total of 123 mammary glands. Intramammary infusions were performed with either L. lactis or PBS for 3 (study 1) or 7 (study 2) consecutive days. Antibiotic-treated and untreated control glands were included. Milk samples for microbiology, somatic cell analysis and milk production were collected before and after treatment.Results/Key findings.L. lactis rapidly activated the mammary glands' innate immune response and initiated an inflammatory response as evidenced by the recruitment of polymorphonuclear neutrophils and increased somatic cell counts. But while leading to a transient clearance of CNS in the gland, this response caused mild to moderate clinical cases of mastitis characterized by abnormal milk secretions and udder inflammation. Moreover, S. aureus infections did not improve, and CNS infections tended to relapse. Under our experimental conditions, the L. lactis treatment led to a transient clearance of the pathogen in the gland, but also caused mild to moderate clinical cases of mastitis. We believe it is still early to implement bacterial formulations as alternatives in treating mastitis in ruminants and further experimentation is needed.

  13. Λ{sub b} → π{sup -}(D{sub s}{sup -})Λ{sub c}(2595), π{sup -}(D{sub s}{sup -})Λ{sub c}(2625) decays and DN, D*N molecular components

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Wei-Hong [Guangxi Normal University, Department of Physics, Guilin (China); Centro Mixto Universidad de Valencia-CSIC Institutos de Investigacion de Paterna, Departamento de Fisica Teorica y IFIC, Valencia (Spain); Bayar, Melahat [Kocaeli University, Department of Physics, Izmit (Turkey); Oset, Eulogio [Centro Mixto Universidad de Valencia-CSIC Institutos de Investigacion de Paterna, Departamento de Fisica Teorica y IFIC, Valencia (Spain)

    2017-01-15

    From the perspective that Λ{sub c}(2595) and Λ{sub c}(2625) are dynamically generated resonances from the DN, D*N interaction and coupled channels, we have evaluated the rates for Λ{sub b} → π{sup -}Λ{sub c}(2595) and Λ{sub b} → π{sup -}Λ{sub c}(2625) up to a global unknown factor that allows us to calculate the ratio of rates and compare with experiment, where good agreement is found. Similarly, we can also make predictions for the ratio of rates of the, yet unknown, decays of Λ{sub b} → D{sub s}{sup -}Λ{sub c}(2595) and Λ{sub b} → D{sub s}{sup -}Λ{sub c}(2625) and make estimates for their individual branching fractions. (orig.)

  14. Effects of ascorbic acid and glucose oxidase levels on the viability of probiotic bacteria and the physical and sensory characteristics in symbiotic ice-cream

    Directory of Open Access Journals (Sweden)

    M. B. Akın

    2015-05-01

    Full Text Available In this study, the effects of addition of different amounts of ascorbic acid and glucose oxidase on the properties of symbiotic ice cream were investigated. Ice-cream containing inulin (2 % (w/w was produced by mixing fortified milk fermented with probiotic strains with the ice-cream mixes containing different ascorbic acid and glucose oxidase concentrations (0.025, 0.05, 0.1 (w/w. The cultures were grown (37 °C, 12 h in UHT skimmed milk. The fermented milk was added to the ice-cream mix up to a level of 10 % w/w. Increasing the concentration of ascorbic acid stimulated the growth of Lactobacillus acidophilus LA-5 (L. acidophilus and Bifidobacterium animalis subsp. lactis BB-12 (Bifidobacterium BB-12. On contrary, increasing the concentration of glucose oxidase negatively affected the growth of L. acidophilus and Bifidobacterium BB-12. However, both, ascorbic acid and glucose oxidase concentration had no effect on physical and sensory properties of ice cream. The results suggested that the addition of ascorbic acid stimulated the growth of L. acidophilus and Bifidobacterium BB-12 and could be recommended for ice cream production.

  15. Genome-wide transcriptional responses to carbon starvation in nongrowing Lactococcus lactis

    NARCIS (Netherlands)

    Ercan, O.; Wels, M.; Smid, E.J.; Kleerebezem, M.

    2015-01-01

    This paper describes the transcriptional adaptations of nongrowing, retentostat cultures of Lactococcus lactis to starvation. Near-zero-growth cultures (µ = 0.0001 h-1) obtained by extended retentostat cultivation were exposed to starvation by termination of the medium supply for 24 h, followed by a

  16. 21 CFR 173.400 - Dimethyldialkylammonium chloride.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Dimethyldialkylammonium chloride. 173.400 Section... HUMAN CONSUMPTION Specific Usage Additives § 173.400 Dimethyldialkylammonium chloride. Dimethyldialkylammonium chloride may be safely used in food in accordance with the following prescribed conditions: (a...

  17. Benefits of Bifidobacterium breve M-16V Supplementation in Preterm Neonates - A Retrospective Cohort Study.

    Science.gov (United States)

    Patole, Sanjay K; Rao, Shripada C; Keil, Anthony D; Nathan, Elizabeth A; Doherty, Dorota A; Simmer, Karen N

    2016-01-01

    Systematic reviews of randomised controlled trials report that probiotics reduce the risk of necrotising enterocolitis (NEC) in preterm neonates. To determine whether routine probiotic supplementation (RPS) to preterm neonates would reduce the incidence of NEC. The incidence of NEC ≥ Stage II and all-cause mortality was compared for an equal period of 24 months 'before' (Epoch 1) and 'after' (Epoch 2) RPS with Bifidobacterium breve M-16V in neonates Bifidobacterium breve M-16V was associated with decreased NEC≥ Stage II and 'NEC≥ Stage II or all-cause mortality' in neonates <34 weeks. Large sample size is required to assess the potential benefits of RPS in neonates <28 weeks.

  18. Assessment of reproductive and developmental effects of DINP, DnHP and DCHP using quantitative weight of evidence.

    Science.gov (United States)

    Dekant, Wolfgang; Bridges, James

    2016-11-01

    Quantitative weight of evidence (QWoE) methodology utilizes detailed scoring sheets to assess the quality/reliability of each publication on toxicity of a chemical and gives numerical scores for quality and observed toxicity. This QWoE-methodology was applied to the reproductive toxicity data on diisononylphthalate (DINP), di-n-hexylphthalate (DnHP), and dicyclohexylphthalate (DCHP) to determine if the scientific evidence for adverse effects meets the requirements for classification as reproductive toxicants. The scores for DINP were compared to those when applying the methodology DCHP and DnHP that have harmonized classifications. Based on the quality/reliability scores, application of the QWoE shows that the three databases are of similar quality; but effect scores differ widely. Application of QWoE to DINP studies resulted in an overall score well below the benchmark required to trigger classification. For DCHP, the QWoE also results in low scores. The high scores from the application of the QWoE methodology to the toxicological data for DnHP represent clear evidence for adverse effects and justify a classification of DnHP as category 1B for both development and fertility. The conclusions on classification based on the QWoE are well supported using a narrative assessment of consistency and biological plausibility. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  19. In Vitro characterization of Lactococcus lactis strains Isolated from Iranian Traditional Dairy Products as a Potential Probiotic

    OpenAIRE

    Fatemeh Nejati; Tobias Oelschlaeger

    2015-01-01

    Few studies have been reported regarding probiotic properties of Lactococcus lactis strains although they are extensively used as starter cultures in the production of dairy products. In this study 8 wild isolates of Lactococcus lactis were evaluated in vitro with regard to resistance to simulated gastric and intestinal juices, adherence ability to Caco-2 cells and HT29-MTX-E12 cell lines, anti-microbial activity, hydrophobicity and antibiotic susceptibility. The results revealed that all iso...

  20. Ornithine transport and exchange in Streptococcus lactis

    International Nuclear Information System (INIS)

    Thompson, J.

    1987-01-01

    Resting cells of Streptococcus lactis 133 appeared to accumulate [ 14 C]ornithine to a high concentration in the absence of an exogenous energy source. However, analysis of intracellular amino acid pool constituents and results of transport experiments revealed that the accumulation of ornithine represented a homoexchange between extracellular [ 14 C]ornithine and unlabeled ornithine in the cell. The energy-independent exchange of ornithine was not inhibited by proton-conducting uncouplers or by metabolic inhibitors. Intracellular [ 14 C]ornithine was retained by resting cells after suspension in a buffered medium. However, addition of unlabeled ornithine to the suspension elicited rapid exit of labeled amino acid. The initial rate of exist of [ 14 C]ornithine was dependent on the concentration of unlabeled ornithine in the medium, but this accelerative exchange diffusion process caused no net loss of amino acid. By contrast, the presence of a fermentable energy source caused a rapid expulsion of and new decrease in the concentration of intracellular ornithine. Kinetic analyses of amino acid transport demonstrated competitive inhibition between lysine and ornithine, and data obtained by two-dimensional thin-layer chromatography established the heteroexchange of these basic amino acids. The effects of amino acids and of ornithine analogs on both entry and exit of [ 14 C]ornithine have been examined. The data suggest that common carrier mediates the entry and exchange of lysine, arginine, and ornithine in cells of S. lactis

  1. AguR is a transmembrane transcription activator of the putrescine biosynthesis operon in Lactococcus lactis, and acts in response to agmatine concentration

    NARCIS (Netherlands)

    Linares, Daniel M; Del Rio, Beatriz; Redruello, Begoña; Ladero, Victor; Martin, Ma Cruz; de Jong, Anne; Kuipers, Oscar P; Fernandez, Maria; Alvarez, Miguel A

    2015-01-01

    Dairy industry fermentative processes mostly use Lactococcus lactis as a starter. However, some dairy L. lactis strains produce putrescine - a biogenic amine that raises food safety and spoilage concerns - via the agmatine deiminase pathway (AGDI). The enzymatic activities responsible for putrescine

  2. Expanding the molecular toolbox for Lactococcus lactis: construction of an inducible thioredoxin gene fusion expression system

    OpenAIRE

    Cambillau Christian; O'Connell-Motherway Mary; Douillard François P; van Sinderen Douwe

    2011-01-01

    Abstract Background The development of the Nisin Inducible Controlled Expression (NICE) system in the food-grade bacterium Lactococcus lactis subsp. cremoris represents a cornerstone in the use of Gram-positive bacterial expression systems for biotechnological purposes. However, proteins that are subjected to such over-expression in L. lactis may suffer from improper folding, inclusion body formation and/or protein degradation, thereby significantly reducing the yield of soluble target protei...

  3. Multi-omics approach to study the growth efficiency and amino acid metabolism in Lactococcus lactis at various specific growth rates

    Directory of Open Access Journals (Sweden)

    Arike Liisa

    2011-02-01

    Full Text Available Abstract Background Lactococcus lactis is recognised as a safe (GRAS microorganism and has hence gained interest in numerous biotechnological approaches. As it is fastidious for several amino acids, optimization of processes which involve this organism requires a thorough understanding of its metabolic regulations during multisubstrate growth. Results Using glucose limited continuous cultivations, specific growth rate dependent metabolism of L. lactis including utilization of amino acids was studied based on extracellular metabolome, global transcriptome and proteome analysis. A new growth medium was designed with reduced amino acid concentrations to increase precision of measurements of consumption of amino acids. Consumption patterns were calculated for all 20 amino acids and measured carbon balance showed good fit of the data at all growth rates studied. It was observed that metabolism of L. lactis became more efficient with rising specific growth rate in the range 0.10 - 0.60 h-1, indicated by 30% increase in biomass yield based on glucose consumption, 50% increase in efficiency of nitrogen use for biomass synthesis, and 40% reduction in energy spilling. The latter was realized by decrease in the overall product formation and higher efficiency of incorporation of amino acids into biomass. L. lactis global transcriptome and proteome profiles showed good correlation supporting the general idea of transcription level control of bacterial metabolism, but the data indicated that substrate transport systems together with lower part of glycolysis in L. lactis were presumably under allosteric control. Conclusions The current study demonstrates advantages of the usage of strictly controlled continuous cultivation methods combined with multi-omics approach for quantitative understanding of amino acid and energy metabolism of L. lactis which is a valuable new knowledge for development of balanced growth media, gene manipulations for desired product

  4. 7 CFR 1150.173 - Confidential treatment.

    Science.gov (United States)

    2010-01-01

    ... reports of the number of persons subject to this subpart or statistical data collected therefrom, which... 7 Agriculture 9 2010-01-01 2009-01-01 true Confidential treatment. 1150.173 Section 1150.173 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing...

  5. 49 CFR 173.174 - Refrigerating machines.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Refrigerating machines. 173.174 Section 173.174 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... Refrigerating machines. A refrigerating machine assembled for shipment and containing 7 kg (15 pounds) or less...

  6. 49 CFR 173.465 - Type A packaging tests.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Type A packaging tests. 173.465 Section 173.465 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... SHIPMENTS AND PACKAGINGS Class 7 (Radioactive) Materials § 173.465 Type A packaging tests. (a) The packaging...

  7. Physiological Studies of Lactococcus lactis

    DEFF Research Database (Denmark)

    Hansen, Gunda

    medium and (specific) acidification activity in milk in response to the extracellular pH (pHex) during batch fermentations and in response to stress during downstream processing and storage as frozen, freeze- and spray-dried cells. In this PhD thesis, in situ flow cytometric viability assessment...... fermentation, downstream processing and storage in the absence of a protectant. However, storing freeze-dried L. lactis cells at 30 °C negatively affected the culturability and acidification activity. The reactivation of freeze-dried cells in fermentation medium prior to flow cytometric viability assessment...

  8. Effect of autochthonous bacteriocin-producing Lactococcus lactis on bacterial population dynamics and growth of halotolerant bacteria in Brazilian charqui.

    Science.gov (United States)

    Biscola, Vanessa; Abriouel, Hikmate; Todorov, Svetoslav Dimitrov; Capuano, Verena Sant'Anna Cabral; Gálvez, Antonio; Franco, Bernadette Dora Gombossy de Melo

    2014-12-01

    Charqui is a fermented, salted and sun-dried meat product, widely consumed in Brazil and exported to several countries. Growth of microorganisms in this product is unlikely due to reduced Aw, but halophilic and halotolerant bacteria may grow and cause spoilage. Charqui is a good source of lactic acid bacteria able to produce antimicrobial bacteriocins. In this study, an autochthonous bacteriocinogenic strain (Lactococcus lactis subsp. lactis 69), isolated from charqui, was added to the meat used for charqui manufacture and evaluated for its capability to prevent the growth of spoilage bacteria during storage up to 45 days. The influence of L. lactis 69 on the bacterial diversity during the manufacturing of the product was also studied, using denaturing gradient gel electrophoresis (DGGE). L. lactis 69 did not affect the counts and diversity of lactic acid bacteria during manufacturing and storage, but influenced negatively the populations of halotolerant microorganisms, reducing the spoilage potential. The majority of tested virulence genes was absent, evidencing the safety and potential technological application of this strain as an additional hurdle to inhibit undesirable microbial growth in this and similar fermented meat products. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Biochemical Characteristics and Viability of Probiotic and Yogurt Bacteria in Yogurt during the Fermentation and Refrigerated Storage

    Directory of Open Access Journals (Sweden)

    F Sarvari

    2014-09-01

    Full Text Available This research aimed to investigate the viability of probiotic bacteria (Lactobacillus acidophilus LA-5 and Bifidobacterium lactis BB-12 and yogurt bacteria (Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus in yogurt during the fermentation, immediately after fermentation and during refrigerated storage (21 d, 4˚C. Also the biochemical characteristics of milk as affected by the commercial 4-strain mixed starter culture were investigated. Storage time affected the viability of all bacterial species. The concentration of lactic acid during the fermentation increased in parallel with the titrable acidity, and the concentration of acetic acid was proportional to the viability of Bifidobacterium lactis. The acetaldehyde level was decreased in the yogurt from day 0 up to the end of the storage. Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus were multiplied considerably during the fermentation. Streptococcus thermophilus could maintain its viability to the highest level, but Lactobacillus delbrueckii ssp. bulgaricus lost its viability rapidly during the cold storage compared to Streptococcus thermophilus. The multiplication and viability of probiotic bacteria were also influenced by the associative strains and species of yogurt organisms. Bifidobacteria counts were satisfactory. The loss of viability for bifidobacteria was gradual and steady during the storage, and they showed good stability during the storage as compared to Lactobacillus acidophilus.

  10. 40 CFR 173.9 - Judicial review.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Judicial review. 173.9 Section 173.9 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PROCEDURES GOVERNING... Judicial review. The State may appeal an order rescinding, in whole or in part, its primary enforcement...

  11. 49 CFR 173.159 - Batteries, wet.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Batteries, wet. 173.159 Section 173.159... Batteries, wet. (a) Electric storage batteries, containing electrolyte acid or alkaline corrosive battery fluid (wet batteries), may not be packed with other materials except as provided in paragraphs (g) and...

  12. 46 CFR 173.051 - Public nautical school ships.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Public nautical school ships. 173.051 Section 173.051 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES PERTAINING TO VESSEL USE School Ships § 173.051 Public nautical school ships. Each public nautical school...

  13. Condensation pool experiments with steam using DN200 blowdown pipe

    International Nuclear Information System (INIS)

    Laine, J.; Puustinen, M.

    2005-08-01

    This report summarizes the results of the condensation pool experiments with steam using a DN200 blowdown pipe. Altogether five experiment series, each consisting of several steam blows, were carried out in December 2004 with a scaled-down test facility designed and constructed at Lappeenranta University of Technology. The main purpose of the experiments was to increase the understanding of different phenomena in the condensation pool during steam discharge. (au)

  14. Oligomerized backbone pilin helps piliated Lactococcus lactis to withstand shear flow.

    Science.gov (United States)

    Castelain, Mickaël; Duviau, Marie-Pierre; Oxaran, Virginie; Schmitz, Philippe; Cocaign-Bousquet, Muriel; Loubière, Pascal; Piard, Jean-Christophe; Mercier-Bonin, Muriel

    2016-09-01

    The present work focuses on the role of pili present at the cell surface of Lactococcus lactis in bacterial adhesion to abiotic (hydrophobic polystyrene) and biotic (mucin-coated polystyrene) surfaces. Native pili-displaying strains and isogenic derivatives in which pilins or sortase C structural genes had been modified were used. Surface physico-chemistry, morphology and shear-flow-induced detachment of lactococcal cells were evaluated. The involvement of pili in L. lactis adhesion was clearly demonstrated, irrespective of the surface characteristics (hydrophobic/hydrophilic, presence or not of specific binding sites). The accessory pilin, PilC, and the backbone pilin, PilB, were revealed to play a major role in adhesion, provided that the PilB was present in its polymerized form. Within the population fraction that remained attached to the surface under increasing shear flow, different association behaviors were observed, showing that pili could serve as anchoring sites thus hampering the effect of shear flow on cell orientation and detachment.

  15. Induced mutants of Streptococcus lactis by gamma irradiation and its effect on milk acidity

    International Nuclear Information System (INIS)

    Daowd, A.H.; Sabbour, M.M.; Newigy, N.A.; Wahab, G.A.M.

    1988-01-01

    Streptococus lactis was exposed to different doses of gamma-irradiation (10, 50, 100 and 150 Kr). The results of acidity production in sterilized milk inoculated by isolates from radiation treatments and control could be summarized in the following: 1. The mean acidity produced by S. lactis isolates after irradiation at 10 Kr increased to be 0.66% than that of control isolates (0.62%). The acidity produced by the isolates of the 50 Kr treatment showed more increment to reach the peak (0.7%). Thereafter, acidity production decreased by isolates of the 100 Kr (0.53%) and 150 Kr (0.51%) treatments. Heme, the 50 Kr treatment could be considered activation dose to S. lactis starter for acid production. 2. Two mutants were selected. Acidity production by mutant I (from 10 Kr treatment) was 0.95%, and that of mutant II (from 50 Kr treatment) was 1.0%, while acid production by the parent S. lactis culture was 0.62%. Concerning the stability of the isolates, it was found that acid production by mutant I and mutant II slightly decreased by time. The mutants were re-irradiated after 37 and 60 days at doses 10, 25 and 50 Kr. Acid production in milk by isolates of the radiation treatments was determined. The following results were obtained: -The re-irradiation of the mutants decreased the ability of the isolates for acid production than that of parent mutants. -The re-irradiation of the mutants after 60 days yielded isolates which showed more reduction in acid produced than of isolates obtained from re-irridation of the mutants after 37-days. -The higher the dose of the re-irradiation of the mutants, the lower the mean of acid production by isolates of the treatment

  16. Physicochemical and functional characterization of a biosurfactant produced by Lactococcus lactis 53

    NARCIS (Netherlands)

    Rodrigues, LR; Teixeira, JA; van der Mei, HC; Oliveira, R

    2006-01-01

    Isolation and identification of key components of the crude biosurfactant produced by Lactococcus lactis 53 was studied. Fractionation was achieved by hydrophobic interaction chromatography which allowed the isolation of a fraction rich in glycoproteins. Molecular (by Fourier transform infrared

  17. 46 CFR 173.062 - Drainage of weather deck.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Drainage of weather deck. 173.062 Section 173.062 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES PERTAINING TO VESSEL USE School Ships § 173.062 Drainage of weather deck. The weather deck of each sailing...

  18. Metabolism of [14C] bicarbonate by Streptococcus lactis: the synthesis, uptake and excretion of aspartate by resting cells

    International Nuclear Information System (INIS)

    Hillier, A.J.; Rice, G.H.; Jago, G.R.

    1978-01-01

    Resting cells of Streptococcus lactis C10 were able to synthesize aspartic acid de novo but could not actively transport aspartic acid into the cell. Intracellular aspartate was excreted from the cell in the presence of glucose but did not exchange with any extracellular amino acids. The results indicate that Str. lactis C10 obtains the aspartic acid it requires for growth by bicarbonate fixation instead of by the utilization of extracellular aspartic acid. (author)

  19. 21 CFR 211.173 - Laboratory animals.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Laboratory animals. 211.173 Section 211.173 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS... Laboratory animals. Animals used in testing components, in-process materials, or drug products for compliance...

  20. 21 CFR 173.240 - Isopropyl alcohol.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Isopropyl alcohol. 173.240 Section 173.240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Solvents...

  1. 49 CFR 173.163 - Hydrogen fluoride.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Hydrogen fluoride. 173.163 Section 173.163... Hydrogen fluoride. (a) Hydrogen fluoride (hydrofluoric acid, anhydrous) must be packaged as follows: (1) In... filling ratio of 0.84. (b) A cylinder removed from hydrogen fluoride service must be condemned in...

  2. Lactococcus lactis is an Efficient Expression System for Mammalian Membrane Proteins Involved in Liver Detoxification, CYP3A4, and MGST1.

    Science.gov (United States)

    Bakari, Sana; Lembrouk, Mehdi; Sourd, Laura; Ousalem, Fares; André, François; Orlowski, Stéphane; Delaforge, Marcel; Frelet-Barrand, Annie

    2016-04-01

    Despite the great importance of human membrane proteins involved in detoxification mechanisms, their wide use for biochemical approaches is still hampered by several technical difficulties considering eukaryotic protein expression in order to obtain the large amounts of protein required for functional and/or structural studies. Lactococcus lactis has emerged recently as an alternative heterologous expression system to Escherichia coli for proteins that are difficult to express. The aim of this work was to check its ability to express mammalian membrane proteins involved in liver detoxification, i.e., CYP3A4 and two isoforms of MGST1 (rat and human). Genes were cloned using two different strategies, i.e., classical or Gateway-compatible cloning, and we checked the possible influence of two affinity tags (6×-His-tag and Strep-tag II). Interestingly, all proteins could be successfully expressed in L. lactis at higher yields than those previously obtained for these proteins with classical expression systems (E. coli, Saccharomyces cerevisiae) or those of other eukaryotic membrane proteins expressed in L. lactis. In addition, rMGST1 was fairly active after expression in L. lactis. This study highlights L. lactis as an attractive system for efficient expression of mammalian detoxification membrane proteins at levels compatible with further functional and structural studies.

  3. Transcriptomic profile of aguR deletion mutant of Lactococcus lactis subsp. cremoris CECT 8666

    Science.gov (United States)

    del Rio, Beatriz; Linares, Daniel M.; Redruello, Begoña; Martin, Maria Cruz; Fernandez, Maria; de Jong, Anne; Kuipers, Oscar P.; Ladero, Victor; Alvarez, Miguel A.

    2015-01-01

    Lactococcus lactis subsp. cremoris CECT 8666 (formerly GE2-14) is a dairy strain that catabolizes agmatine (a decarboxylated derivative of arginine) into the biogenic amine putrescine by the agmatine deiminase (AGDI) pathway [1]. The AGDI cluster of L. lactis is composed by five genes aguR, aguB, aguD, aguA and aguC. The last four genes are responsible for the deamination of agmatine to putrescine and are co-transcribed as a single policistronic mRNA forming the catabolic operon aguBDAC[1]. aguR encodes a transmembrane protein that functions as a one-component signal transduction system that senses the agmatine concentration of the medium and accordingly regulates the transcription of aguBDAC[2], which is also transcriptionally regulated by carbon catabolic repression (CCR) via glucose, but not by other sugars such as lactose and galactose [1], [3]. Here we report the transcriptional profiling of the aguR gene deletion mutant (L. lactis subsp. cremoris CECT 8666 ∆aguR) [2] compared to the wild type strain, both grown in M17 medium with galactose as carbon source and supplemented with agmatine. The transcriptional profiling data of AguR-regulated genes were deposited in the Gene Expression Omnibus (GEO) database under accession no. GSE59514. PMID:26697381

  4. Transcriptomic profile of aguR deletion mutant of Lactococcus lactis subsp. cremoris CECT 8666

    Directory of Open Access Journals (Sweden)

    Beatriz del Rio

    2015-12-01

    Full Text Available Lactococcus lactis subsp. cremoris CECT 8666 (formerly GE2-14 is a dairy strain that catabolizes agmatine (a decarboxylated derivative of arginine into the biogenic amine putrescine by the agmatine deiminase (AGDI pathway [1]. The AGDI cluster of L. lactis is composed by five genes aguR, aguB, aguD, aguA and aguC. The last four genes are responsible for the deamination of agmatine to putrescine and are co-transcribed as a single policistronic mRNA forming the catabolic operon aguBDAC [1]. aguR encodes a transmembrane protein that functions as a one-component signal transduction system that senses the agmatine concentration of the medium and accordingly regulates the transcription of aguBDAC [2], which is also transcriptionally regulated by carbon catabolic repression (CCR via glucose, but not by other sugars such as lactose and galactose [1,3]. Here we report the transcriptional profiling of the aguR gene deletion mutant (L. lactis subsp. cremoris CECT 8666 ∆aguR [2] compared to the wild type strain, both grown in M17 medium with galactose as carbon source and supplemented with agmatine. The transcriptional profiling data of AguR-regulated genes were deposited in the Gene Expression Omnibus (GEO database under accession no. GSE59514.

  5. Inside the adaptation process of Lactobacillus delbrueckii subsp. lactis to bile.

    Science.gov (United States)

    Burns, Patricia; Sánchez, Borja; Vinderola, Gabriel; Ruas-Madiedo, Patricia; Ruiz, Lorena; Margolles, Abelardo; Reinheimer, Jorge; de los Reyes-Gavilán, Clara G

    2010-08-15

    Progressive adaptation to bile might render some lactobacilli able to withstand physiological bile salt concentrations. In this work, the adaptation to bile was evaluated on previously isolated dairy strains of Lactobacillus delbrueckii subsp. lactis 200 and L. delbrueckii subsp. lactis 200+, a strain derived thereof with stable bile-resistant phenotype. The adaptation to bile was obtained by comparing cytosolic proteomes of both strains grown in the presence or absence of bile. Proteomics were complemented with physiological studies on both strains focusing on glycolytic end-products, the ability to adhere to the human intestinal epithelial cell line HT29-MTX and survival to simulated gastrointestinal conditions. Protein pattern comparison of strains grown with and without bile allowed us to identify 9 different proteins whose production was regulated by bile in both strains, and 17 proteins that showed differences in their levels between the parental and the bile-resistant derivative. These included general stress response chaperones, proteins involved in transcription and translation, in peptidoglycan/exopolysaccharide biosynthesis, in the lipid and nucleotide metabolism and several glycolytic and pyruvate catabolism enzymes. Differences in the level of metabolic end-products of the sugar catabolism were found between the strains 200 and 200+. A decrease in the adhesion of both strains to the intestinal cell line was detected in the presence of bile. In simulated gastric and intestinal juices, a protective effect was exerted by milk improving the survival of both microorganisms. These results indicate that bile tolerance in L. delbrueckii subsp. lactis involves several mechanisms responding to the deleterious impact of bile salts on bacterial physiology. Copyright 2010 Elsevier B.V. All rights reserved.

  6. Lactococcus lactis subsp. cremoris strain JFR1 attenuates Salmonella adhesion to human intestinal cells in vitro.

    Science.gov (United States)

    Zhang, Justina Su; Guri, Anilda; Corredig, Milena; Morales-Rayas, Rocio; Hassan, Ashraf; Griffiths, Mansel; LaPointe, Gisèle

    2016-12-01

    Lactococcus lactis subsp. cremoris JFR1 has been studied in reduced fat cheese due to its ability to produce exopolysaccharides (EPS) in situ, contributing to improved textural and organoleptic properties. In this study, the effect of strain JFR1 on virulence gene expression and attachment of Salmonella to HT-29 human colon carcinoma cells was investigated. Overnight cultures of L. lactis subsp. cremoris JFR1 containing EPS, grown in M17 media with 0.5% glucose supplementation, decreased attachment as well as down regulated virulence gene expression in Salmonella enterica subsp. enterica when tested on HT-29 cells. However, EPS isolated from milk fermented with L. lactis subsp. cremoris JFR1 did not affect Salmonella virulence gene expression or attachment to HT-29 cells. These results suggest that EPS does not contribute to the attachment of Salmonella to human intestinal cells. However, the possibility that the isolation process may have affected the structural features of EPS cannot be ruled out. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. 49 CFR 173.31 - Use of tank cars.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Use of tank cars. 173.31 Section 173.31... SHIPMENTS AND PACKAGINGS Preparation of Hazardous Materials for Transportation § 173.31 Use of tank cars. (a) General. (1) No person may offer a hazardous material for transportation in a tank car unless the tank car...

  8. Overexpression of an orchid (Dendrobium nobile SOC1/TM3-like ortholog, DnAGL19, in Arabidopsis regulates HOS1-FT expression

    Directory of Open Access Journals (Sweden)

    Xiao-ru eLiu

    2016-02-01

    Full Text Available Flowering in the appropriate season is critical for successful reproduction in angiosperms. The orchid species, Dendrobium nobile, requires vernalization to achieve flowering in the spring, but the underlying regulatory network has not been identified to date. The MADS-box transcription factor DnAGL19 was previously identified in a study of low-temperature treated D. nobile buds and was suggested to regulate vernalization-induced flowering. In this study, phylogenetic analysis of DnAGL9 and the MADS-box containing proteins showed that DnAGL19 is phylogenetically closely related to the SOC1-like protein from orchid Dendrobium Chao Parya Smile, DOSOC1. The orchid clade closed to but is not included into the SOC1-1/TM3 clades associated with either eudicots or monocots, suggesting that DnAGL19 is an SOC1-1/TM3-like ortholog. DnAGL19 was found to be highly expressed in pseudobulbs, leaves, roots and axillary buds but rarely in flowers, and to be substantially upregulated in axillary buds by prolonged low-temperature treatments. Overexpression of DnAGL19 in Arabidopsis thaliana resulted in a small but significantly reduced time to bolting, suggesting that flowering time was slightly accelerated under normal growth conditions. Consistent with this, the A. thaliana APETELA1 (AP1 gene was expressed at an earlier stage in transgenic lines than in wild type plants, while the FLOWERING LOCUS T (FT gene was suppressed, suggesting that altered regulations on these transcription factors caused the weak promotion of flowering. HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENE 1 (HOS1 was slightly activated under the same conditions, suggesting that the HOS1-FT module may be involved in the DnAGL19-related network. Under vernalization conditions, FT expression was significantly upregulated, whereas HOS1 expression in the transgenic A. thaliana has a level similar to that in wild type. Taken together, these results suggest that DnAGL19 controls the action of the

  9. Long-term multi-species Lactobacillus and Bifidobacterium dietary supplement enhances memory and changes regional brain metabolites in middle-aged rats.

    Science.gov (United States)

    O'Hagan, Caroline; Li, Jia V; Marchesi, Julian R; Plummer, Sue; Garaiova, Iveta; Good, Mark A

    2017-10-01

    Ageing is associated with changes in the gut microbiome that may contribute to age-related changes in cognition. Previous work has shown that dietary supplements with multi-species live microorganisms can influence brain function, including induction of hippocampal synaptic plasticity and production of brain derived neurotrophic factor, in both young and aged rodents. However, the effect of such dietary supplements on memory processes has been less well documented, particularly in the context of aging. The main aim of the present study was to examine the impact of a long-term dietary supplement with a multi-species live Lactobacillus and Bifidobacteria mixture (Lactobacillus acidophilus CUL60, L. acidophilus CUL21, Bifidobacterium bifidum CUL20 and B. lactis CUL34) on tests of memory and behavioural flexibility in 15-17-month-old male rats. Following behavioural testing, the hippocampus and prefrontal cortex was extracted and analysed ex vivo using 1 H nuclear magnetic resonance ( 1 H NMR) spectroscopy to examine brain metabolites. The results showed a small beneficial effect of the dietary supplement on watermaze spatial navigation and robust improvements in long-term object recognition memory and short-term memory for object-in-place associations. Short-term object novelty and object temporal order memory was not influenced by the dietary supplement in aging rats. 1 H NMR analysis revealed diet-related regional-specific changes in brain metabolites; which indicated changes in several pathways contributing to modulation of neural signaling. These data suggest that chronic dietary supplement with multi-species live microorganisms can alter brain metabolites in aging rats and have beneficial effects on memory. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Complete Genome Sequence of Bifidobacterium bifidum S17▿

    Science.gov (United States)

    Zhurina, Daria; Zomer, Aldert; Gleinser, Marita; Brancaccio, Vincenco Francesco; Auchter, Marc; Waidmann, Mark S.; Westermann, Christina; van Sinderen, Douwe; Riedel, Christian U.

    2011-01-01

    Here, we report on the first completely annotated genome sequence of a Bifidobacterium bifidum strain. B. bifidum S17, isolated from feces of a breast-fed infant, was shown to strongly adhere to intestinal epithelial cells and has potent anti-inflammatory activity in vitro and in vivo. The genome sequence will provide new insights into the biology of this potential probiotic organism and allow for the characterization of the molecular mechanisms underlying its beneficial properties. PMID:21037011

  11. 49 CFR 173.185 - Lithium cells and batteries.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Lithium cells and batteries. 173.185 Section 173... Class 7 § 173.185 Lithium cells and batteries. (a) Cells and batteries. A lithium cell or battery, including a lithium polymer cell or battery and a lithium-ion cell or battery, must conform to all of the...

  12. Potencial do soro de leite líquido como agente encapsulante de Bifidobacterium Bb-12 por spray drying: comparação com goma arábica Potential of liquid whey as the encapsulating agent of Bifidobacterium Bb-12 by spray drying: comparison with arabic gum

    Directory of Open Access Journals (Sweden)

    Fabiane Picinin de Castro-Cislaghi

    2012-09-01

    Full Text Available O objetivo do trabalho foi avaliar o potencial do soro de leite líquido como agente encapsulante de Bifidobacterium Bb-12 por spray drying, comparando-o com a goma arábica, a qual é tradicionalmente utilizada na tecnologia de microencapsulação. Foram determinados o rendimento da microencapsulação e a viabilidade das microcápsulas durante o armazenamento. Quando o soro de leite foi utilizado como agente encapsulante, o rendimento da microencapsulação foi maior e a viabilidade das células manteve-se elevada e constante durante doze semanas. O soro de leite apresentou-se como um eficiente agente encapsulante de Bifidobacterium por spray drying.The objective of this study was to evaluate the potential of liquid whey as the encapsulating agent Bifidobacterium Bb-12 by spray drying, compared with arabic gum, which is typically used in microencapsulation technology. The microencapsulation yield and viability during storage were determined. When the whey was used as the encapsulating agent, the microencapsulation yield was higher, and cell viability remained high and steady for twelve weeks. The whey was shown to be an effective encapsulating agent of Bifidobacterium by spray drying.

  13. Benzoic Acid Production with Respect to Starter Culture and Incubation Temperature during Yogurt Fermentation using Response Surface Methodology.

    Science.gov (United States)

    Yu, Hyung-Seok; Lee, Na-Kyoung; Jeon, Hye-Lin; Eom, Su Jin; Yoo, Mi-Young; Lim, Sang-Dong; Paik, Hyun-Dong

    2016-01-01

    Benzoic acid is occasionally used as a raw material supplement in food products and is sometimes generated during the fermentation process. In this study, the production of naturally occurring yogurt preservatives was investigated for various starter cultures and incubation temperatures, and considered food regulations. Streptococcus thermophilus, Lactobacillus acidophilus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus rhamnosus, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus reuteri, Lactobacillus plantarum, Bifidobacterium longum, Bifidobacterium lactis, Bifidobacterium bifidum, Bifidobacterium infantis, and Bifidobacterium breve were used as yogurt starter cultures in commercial starters. Among these strains, L. rhamnosus and L. paracasei showed the highest production of benzoic acid. Therefore, the use of L. rhamnosus, L. paracasei, S. thermophilus, and different incubation temperatures were examined to optimize benzoic acid production. Response surface methodology (RSM) based on a central composite design was performed for various incubation temperatures (35-44℃) and starter culture inoculum ratios (0-0.04%) in a commercial range of dairy fermentation processes. The optimum conditions were 0.04% L. rhamnosus, 0.01% L. paracasei, 0.02% S. thermophilus, and 38.12℃, and the predicted and estimated concentrations of benzoic acid were 13.31 and 13.94 mg/kg, respectively. These conditions maximized naturally occurring benzoic acid production during the yogurt fermentation process, and the observed production levels satisfied regulatory guidelines for benzoic acid in dairy products.

  14. Microbial domestication signatures of Lactococcus lactis can be reproduced by experimental evolution

    NARCIS (Netherlands)

    Bachmann, H.; Starrenburg, M.J.C.; Molenaar, D.; Kleerebezem, M.; Hylckama Vlieg, van J.E.T.

    2012-01-01

    Experimental evolution is a powerful approach to unravel how selective forces shape microbial genotypes and phenotypes. To this date, the available examples focus on the adaptation to conditions specific to the laboratory. The lactic acid bacterium Lactococcus lactis naturally occurs on plants and

  15. Microbial domestication signatures of Lactococcus lactis can be reproduced by experimental evolution.

    NARCIS (Netherlands)

    Bachmann, H.; Starrenburg, M.J.; Molenaar, D.; Kleerebezem, M.; van Hylckama Vlieg, J.E.T.

    2012-01-01

    Experimental evolution is a powerful approach to unravel how selective forces shape microbial genotypes and phenotypes. To this date, the available examples focus on the adaptation to conditions specific to the laboratory. The lactic acid bacterium Lactococcus lactis naturally occurs on plants and

  16. Efficacy of Bifidobacterium breve Fermented Milk in Maintaining Remission of Ulcerative Colitis.

    Science.gov (United States)

    Matsuoka, Katsuyoshi; Uemura, Yukari; Kanai, Takanori; Kunisaki, Reiko; Suzuki, Yasuo; Yokoyama, Kaoru; Yoshimura, Naoki; Hibi, Toshifumi

    2018-02-15

    Fermented milk products containing Bifidobacterium breve strain Yakult (BFM) may improve clinical status in ulcerative colitis (UC) patients. To assess efficacy of BFM in maintaining remission in Japanese patients with quiescent UC. This double-blind study (B-FLORA) enrolled 195 patients with quiescent UC, randomized to receive one pack of BFM fermented milk per day [Bifidobacterium breve strain Yakult (10 billion bacteria) and Lactobacillus acidophilus (1 billion bacteria)] (n = 98) or matching placebo (n = 97) for 48 weeks. The primary efficacy endpoint was relapse-free survival (relapse: rectal bleeding score ≥ 2 on Sutherland disease activity index scale for 3 consecutive days and/or initiation of remission induction therapy for worsening of UC). An interim analysis was conducted after inclusion and follow-up of one-third of patients for the first phase of the study (n = 195). Relapse-free survival was not significantly different between the BFM and placebo groups (P = 0.643; hazard ratio 1.16; 95% CI 0.63-2.14, log-rank test), nor was the incidence of relapse. Therefore, the study was discontinued for lack of efficacy. An exploratory analysis of fecal samples from a subgroup of patients revealed no effects of either study beverage on intestinal microbiota, but there was a significant decrease in Bifidobacterium species before relapse, regardless of treatment group. Three mild adverse events occurred for which a causal relationship with the study beverage could not be ruled out (placebo: abdominal bloating and stress in one patient; BFM: body odor in one patient). BFM had no effect on time to relapse in UC patients compared with placebo. UMIN000007593.

  17. Isolation and characterisation of an enterocin P-producing Enterococcus lactis strain from a fresh shrimp (Penaeus vannamei).

    Science.gov (United States)

    Ben Braïek, Olfa; Ghomrassi, Hamdi; Cremonesi, Paola; Morandi, Stefano; Fleury, Yannick; Le Chevalier, Patrick; Hani, Khaled; Bel Hadj, Omrane; Ghrairi, Taoufik

    2017-06-01

    Screening for lactic acid bacteria (LAB) from fresh shrimp samples (Penaeus vannamei) collected from retail seafood markets in the Tunisian's coast, resulted in the isolation of an Enterococcus strain termed Q1. This strain was selected for its antagonistic activity against pathogenic bacteria such as Listeria monocytogenes, Pseudomonas aeruginosa, Lactococcus garvieae and against fungi (Aspergillus niger and Fusarium equiseti). The Q1 strain was characterised using standard morphological and biochemical tests, growth assays at different temperatures, pH and salinity. 16S rRNA, rpoA and pheS gene sequencing, as well as the 16S-23S rRNA intergenic spacer analyses, were combined to identify strain Q1 as a strain of Enterococcus lactis. The bacteriocin produced by E. lactis Q1 is thermostable, active in the pH range from 4.0 to 9.0 and has a bactericidal mode of action. The enterocin P structural gene was detected by specific PCR in strain E. lactis Q1, which is in good agreement with SDS-PAGE data of the purified bacteriocin. A lack of significant antibiotic resistance genes and virulence determinants was confirmed by specific PCRs. This work provides the first description of an enterocin P producer E. lactis strain isolated from a fresh shrimp. Based on its safety properties (absence of haemolytic activity, virulence factors and antibiotic resistance genes), this strain has the potential to be used as a natural additive or adjunct protective culture in food biopreservation and/or probiotic culture.

  18. Classification of a moderately oxygen-tolerant isolate from baby faeces as Bifidobacterium thermophilum

    Directory of Open Access Journals (Sweden)

    Fliss Ismaïl

    2007-08-01

    Full Text Available Abstract Background Bifidobacteria are found at varying prevalence in human microbiota and seem to play an important role in the human gastrointestinal tract (GIT. Bifidobacteria are highly adapted to the human GIT which is reflected in the genome sequence of a Bifidobacterim longum isolate. The competitiveness against other bacteria is not fully understood yet but may be related to the production of antimicrobial compounds such as bacteriocins. In a previous study, 34 Bifidobacterium isolates have been isolated from baby faeces among which six showed proteinaceous antilisterial activity against Listeria monocytogenes. In this study, one of these isolates, RBL67, was further identified and characterized. Results Bifidobacterium isolate RBL67 was classified and characterized using a polyphasic approach. RBL67 was classified as Bifidobacterium thermophilum based on phenotypic and DNA-DNA hybridization characteristics, although 16S rDNA analyses and partial groEL sequences showed higher homology with B. thermacidophilum subsp. porcinum and B. thermacidophilum subsp. thermacidophilum, respectively. RBL67 was moderately oxygen-tolerant and was able to grow at pH 4 and at a temperature of 47°C. Conclusion In order to assign RBL67 to a species, a polyphasic approach was used. This resulted in the classification of RBL67 as a Bifidobacterium thermophilum strain. To our knowledge, this is the first report about B. thermophilum isolated from baby faeces since the B. thermophilum strains were related to ruminants and swine faeces before. B. thermophilum was previously only isolated from animal sources and was therefore suggested to be used as differential species between animal and human contamination. Our findings may disapprove this suggestion and further studies are now conducted to determine whether B. thermophilum is distributed broader in human faeces. Furthermore, the postulated differentiation between human and animal strains by growth above 45

  19. Genomic and fluxomic analysis of carbohydrate metabolism in Bifidobacterium spp: human symbiotic bacteria

    Science.gov (United States)

    Bifidobacteria are gram-positive microorganisms widely applied in fermented dairy products due to their health-promoting effects. Bifidobacterium ssp. may also represent up to 91% of microbial gut population in the infant colon, but considerably less in adults. Fructose-6 phosphate phosphoketolase...

  20. Natural sweetening of food products by engineering Lactococcus lactis for glucose production

    NARCIS (Netherlands)

    Pool, Wietske A.; Neves, Ana Rute; Kok, Jan; Santos, Helena; Kuipers, Oscar P.

    We show that sweetening of food products by natural fermentation can be achieved by a combined metabolic engineering and transcriptome analysis approach. A Lactococcus lactis ssp. cremoris strain was constructed in which glucose metabolism was completely disrupted by deletion of the genes coding for