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Sample records for animalis subsp lactis

  1. 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.

  2. 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 ......, phosphate or exopolysaccharides, or to belong to the F1F0-ATP-synthetase complex and the protein translocation machinery, respectively....

  3. Selective enumeration and viability of Bifidobacterium animalis subsp. lactis in a new fermented milk product Enumeração seletiva e viabilidade de Bifidobacterium animalis subsp. lactis em um novo produto lácteo fermentado

    Directory of Open Access Journals (Sweden)

    Adriane Elisabete Costa Antunes

    2007-03-01

    Full Text Available One of the key focuses of today's dairy industry worldwide is the continued development of new products, especially probiotic-based products. Buttermilk is originally a by-product of butter making fermented by Mesophilic Aromatic Cultures (MAC. It can also be made by fermentation of pasteurized whole milk or skimmed milk. This product is not marketed in Brazil. The objectives of this work were: (1 to develop a selective medium for Bifidobacterium animalis subsp. lactis enumeration and (2 to determine the viability of this microorganism during the shelf life of the buttermilk. Skim milk added with 10% sucrose or 0.03% sucralose was pasteurized and inoculated with a composite starter culture consisting of 1% MAC (containing Lactococcus lactis subsp. cremoris, Lactococcus lactis subsp. lactis, Lactococcus lactis subsp. lactis biovar. diacetylactis and Leuconostoc mesenteroides subsp. cremoris and 2% Bifidobacterium animalis subsp. lactis. To attain selective counts of Bif. animalis subsp. lactis the MRS agar supplemented with 0.5% L-cysteine hydrochloride at 10%, 1% lithium chloride at 10%, 0.01% aniline blue and 0.5% dicloxacillin at 0.1% was modified by increasing the antibiotic concentration, addition of NaCl, adjusting pH to 4.8 or increasing the incubation temperature (from 37 to 45ºC. Raising the incubation temperature to 45ºC was found to be efficient in inhibiting the MAC cultures, even in media not added with dicloxacillin. Bif. animalis subsp. lactis exhibited high viability in the product. The buttermilk product prepared with sucrose and sweetener contained in excess of 10(8 cfu.ml-1 bifidobacteria throughout the shelf life of the product (28 days.Atualmente, um dos principais focos da indústria de laticínios em todo o mundo é o desenvolvimento de novos produtos, especialmente probióticos. Buttermilk é originalmente um sub-produto do processamento da manteiga fermentado por Culturas Aromáticas Mesofílicas (MAC. Pode também ser

  4. 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.

  5. 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

  6. 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.

  7. Dose-response study of probiotic bacteria Bifidobacterium animalis subsp lactis BB-12 and Lactobacillus paracasei subsp paracasei CRL-341 in healthy young adults

    DEFF Research Database (Denmark)

    Larsen, C.N.; Nielsen, S.; Kaestel, P.

    2006-01-01

    Objective: This study was performed to investigate the dose-response effects of supplementation with Bifidobacterium animalis subsp lactis (BB-12) and Lactobacillus paracasei subsp paracasei (CRL-431) on blood lipids, recovery from feces and bowel habits. Changes of the fecal microflora was analy...

  8. A randomised double-blind placebo-controlled trial with Lactobacillus acidophilus La-5 and Bifidobacterium animalis subsp. lactis BB-12 for maintenance of remission in ulcerative colitis

    DEFF Research Database (Denmark)

    Wildt, Signe; Nordgaard, Inge; Hansen, Ulla

    2011-01-01

    To investigate the clinical effect of treatment with Lactobacillus acidophilus La-5 and Bifidobacterium animalis subsp. lactis BB-12 (Probio-Tec AB-25) to maintain remission in patients with ulcerative colitis.......To investigate the clinical effect of treatment with Lactobacillus acidophilus La-5 and Bifidobacterium animalis subsp. lactis BB-12 (Probio-Tec AB-25) to maintain remission in patients with ulcerative colitis....

  9. 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.

  10. The Science behind the Probiotic Strain Bifidobacterium animalis subsp. lactis BB-12(®).

    Science.gov (United States)

    Jungersen, Mikkel; Wind, Anette; Johansen, Eric; Christensen, Jeffrey E; Stuer-Lauridsen, Birgitte; Eskesen, Dorte

    2014-03-28

    This review presents selected data on the probiotic strain Bifidobacterium animalis subsp. lactis BB-12(®) (BB-12(®)), which is the world's most documented probiotic Bifidobacterium. It is described in more than 300 scientific publications out of which more than 130 are publications of human clinical studies. The complete genome sequence of BB-12(®) has been determined and published. BB-12(®) originates from Chr. Hansen's collection of dairy cultures and has high stability in foods and as freeze dried powders. Strain characteristics and mechanisms of BB-12(®) have been established through extensive in vitro testing. BB-12(®) exhibits excellent gastric acid and bile tolerance; it contains bile salt hydrolase, and has strong mucus adherence properties, all valuable probiotic characteristics. Pathogen inhibition, barrier function enhancement, and immune interactions are mechanisms that all have been demonstrated for BB-12(®). BB-12(®) has proven its beneficial health effect in numerous clinical studies within gastrointestinal health and immune function. Clinical studies have demonstrated survival of BB-12(®) through the gastrointestinal tract and BB-12(®) has been shown to support a healthy gastrointestinal microbiota. Furthermore, BB-12(®) has been shown to improve bowel function, to have a protective effect against diarrhea, and to reduce side effects of antibiotic treatment, such as antibiotic-associated diarrhea. In terms of immune function, clinical studies have shown that BB-12(®) increases the body's resistance to common respiratory infections as well as reduces the incidence of acute respiratory tract infections.

  11. Bifidobacterium animalis subsp lactis CNCM-I2494 restores gut barrier permeability in chronically low-grade inflamed mice

    Directory of Open Access Journals (Sweden)

    Rebeca eMartín

    2016-05-01

    Full Text Available 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 subsp lactis CNCM-I2494, a strain used in fermented dairy products. A chronic 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 subsp 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 (MLN. 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 subsp lactis CNCM-I2494 may efficiently prevent disorders associated with increased barrier permeability.

  12. 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

  13. Impact of coculturing Bifidobacterium animalis subsp. lactis HN019 with yeasts on microbial viability and metabolite formation.

    Science.gov (United States)

    Toh, M; Liu, S-Q

    2017-10-01

    To evaluate the impact of coculturing Bifidobacterium animalis subsp. lactis HN019 with yeasts on microbial viability and metabolite production. Monocultures and bacteria-yeast cocultures of B. lactis HN019 and 10 different yeast strains belonging to different species in skim milk media were fermented at 37°C. The presence of yeasts enhanced the growth rate and metabolic activities of B. lactis HN019, which might be attributed to their antioxidative properties. The viability of yeasts, when cocultured with bifidobacteria, was either unaffected or suppressed, depending on the strain. When the B. lactis HN019 monoculture and cocultures with Saccharomyces cerevisiae EC-1118, Pichia kluyveri FrootZen and Kluyveromyces lactis KL71 were fermented to pH 4·7, there were no significant differences in their organic acid composition. On the other hand, cocultures produced significantly higher quantities of alcohols and/or esters than the monoculture. Coculturing B. lactis HN019 with yeasts did not improve the viability of the probiotic during storage at 10°C for 8 weeks, as the bifidobacteria itself demonstrated satisfactory survival in the fermented SMM. Coculturing B. lactis HN019 with yeasts accelerated the growth of the bifidobacteria and increased the production aroma-active volatile metabolites. This study demonstrates the potential of utilizing specific yeast species as starter or adjunct cultures to simultaneously improve the growth of fastidious bifidobacteria and modulate the organoleptic properties of fermented food products. © 2017 The Society for Applied Microbiology.

  14. The Science behind the Probiotic Strain Bifidobacterium animalis subsp. lactis BB-12®

    Science.gov (United States)

    Jungersen, Mikkel; Wind, Anette; Johansen, Eric; Christensen, Jeffrey E.; Stuer-Lauridsen, Birgitte; Eskesen, Dorte

    2014-01-01

    This review presents selected data on the probiotic strain Bifidobacterium animalis subsp. lactis BB-12® (BB-12®), which is the world’s most documented probiotic Bifidobacterium. It is described in more than 300 scientific publications out of which more than 130 are publications of human clinical studies. The complete genome sequence of BB-12® has been determined and published. BB-12® originates from Chr. Hansen’s collection of dairy cultures and has high stability in foods and as freeze dried powders. Strain characteristics and mechanisms of BB-12® have been established through extensive in vitro testing. BB-12® exhibits excellent gastric acid and bile tolerance; it contains bile salt hydrolase, and has strong mucus adherence properties, all valuable probiotic characteristics. Pathogen inhibition, barrier function enhancement, and immune interactions are mechanisms that all have been demonstrated for BB-12®. BB-12® has proven its beneficial health effect in numerous clinical studies within gastrointestinal health and immune function. Clinical studies have demonstrated survival of BB-12® through the gastrointestinal tract and BB-12® has been shown to support a healthy gastrointestinal microbiota. Furthermore, BB-12® has been shown to improve bowel function, to have a protective effect against diarrhea, and to reduce side effects of antibiotic treatment, such as antibiotic-associated diarrhea. In terms of immune function, clinical studies have shown that BB-12® increases the body’s resistance to common respiratory infections as well as reduces the incidence of acute respiratory tract infections. PMID:27682233

  15. Dose-response study of probiotic bacteria Bifidobacterium animalis subsp lactis BB-12 and Lactobacillus paracasei subsp paracasei CRL-341 in healthy young adults

    DEFF Research Database (Denmark)

    Larsen, C.N.; Nielsen, S.; Kaestel, P.

    2006-01-01

    Objective: This study was performed to investigate the dose-response effects of supplementation with Bifidobacterium animalis subsp lactis (BB-12) and Lactobacillus paracasei subsp paracasei (CRL-431) on blood lipids, recovery from feces and bowel habits. Changes of the fecal microflora was analy......Objective: This study was performed to investigate the dose-response effects of supplementation with Bifidobacterium animalis subsp lactis (BB-12) and Lactobacillus paracasei subsp paracasei (CRL-431) on blood lipids, recovery from feces and bowel habits. Changes of the fecal microflora...... was analyzed in the 10(10) CFU/day probiotic and placebo group. Design: The study was designed as a randomized, placebo-controlled, double-blinded, parallel dose-response study. Subjects: Healthy young adults (18 - 40 years) were recruited by advertising in local newspapers. Of the 75 persons enrolled, 71 ( 46...... women, 25 men, mean age 25.6 years ( range 18 - 40 years)) completed the study. Intervention: The volunteers were randomly assigned into five groups receiving either placebo or a mixture of the two probiotics in the concentration of 10(8), 10(9), 10(10) or 10(11) CFU/day in 2 weeks run-in period, 3...

  16. Influence of probiotic strain Bifidobacterium animalis subsp. lactis lafti® b94, inulin and transglutaminase on the properties of set- style yoghurt

    Directory of Open Access Journals (Sweden)

    Maja Benković

    2008-05-01

    Full Text Available The aim of this research was to examine the influence of probiotic strain Bifidobacterium animalis subsp. lactis LAFTI® B94, inulin and transglutaminase on quality and sensory properties of set-style yoghurt. Fresh, homogenized milk with 3,3% of milk fat was used for yoghurt production, with addition of Bifidobacterium animalis subsp. lactis LAFTI® B94, inulin and transglutaminase activated during 1h 30 min at 55 °C. Enzyme inactivation was carried out by pasteurization of milk during 15 minutes at 85 °C. Control samples were prepared without addition of probiotic culture, inulin and transglutaminase. Physico-chemical parameters and sensory properties of produced set-style yoghurt have been determined. For reliable identification of probiotic strain Bifidobacterium animalis subsp. lactis LAFTI® B94, isolated from the produced yoghurt, SDS-PAGE of whole cell proteins and PCR with species specific primers for Bifidobacterium were carried out. It has been shown that produced set-style yoghurt with probiotic strain Bifidobacterium animalis subsp. lactis LAFTI® B94, inulin and transglutaminase had higher firmness, less syneresis and better sensory properties than control yoghurt samples. After 28 days of storage the viable count of Bifidobacterium animalis subsp. lactis LAFTI® B94 was higher in samples containing inulin as prebiotic. Fermentation of yoghurt samples containing inulin and transglutaminase lasted shorter than fermentation of samples without inulin and transglutaminase. The presence of high number of probiotic culture (more than 106 cells/mL in produced set yoghurts was confirmed by SDS-PAGE of whole cell proteins and PCR with species specific primers for Bifidobacterium

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

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    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. Probiotic treatment of collagenous colitis: a randomized, double-blind, placebo-controlled trial with Lactobacillus acidophilus and Bifidobacterium animalis subsp. Lactis

    DEFF Research Database (Denmark)

    Wildt, Signe; Munck, Lars K; Vinter-Jensen, Lars

    2006-01-01

    Probiotic treatment may be effective in diseases involving gut microflora and intestinal inflammation. In collagenous colitis (CC), a potential pathogenic role of the gut microflora has been proposed. The effect of probiotic treatment in CC is unknown. Our aim was to investigate the clinical effe...... of treatment with Lactobacillus acidophilus LA-5 and Bifidobacterium animalis subsp. lactis BB-12 (AB-Cap-10) in patients with CC....

  19. 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.

  20. 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...

  1. 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.

  2. 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.

  3. 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.

  4. 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

    , we report the biochemical properties of the first family 5 subfamily 8 glycoside hydrolase (GH5_8) mannanase from the probiotic bacterium Bifidobacterium animalis subsp. lactis Bl-04 (BlMan5_8). BlMan5_8 possesses a novel low affinity carbohydrate binding module (CBM) specific for soluble mannan...... properties to support specialization towards a preferred substrate, which is likely to confer an advantage in the adaptation to competitive ecological niches....

  5. Calcium alginate-resistant starch mixed gel improved the survival of Bifidobacterium animalis subsp lactis Bb12 and Lactobacillus rhamnosus LBRE-LSAS in yogurt and simulated gastrointestinal conditions

    OpenAIRE

    ZIAR, Hasnia; Gerard, Philippe; Riazi, Ali

    2012-01-01

    The aim of this study was to investigate the protective effect of microencapsulation in calcium alginate-resistant starch mixed gel of a new human isolated strain of Lactobacillus rhamnosus LBRE-LSAS compared with the probiotic strain of Bifidobacterium animalis subsp. lactis Bb12. Influence of microencapsulation was tested under deleterious digestive environment, when challenged to salivary a-amylase, to simulated gastric fluid and to simulated intestinal fluid. Bacterial survival, post-acid...

  6. 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.

  7. 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.

  8. Impact of orally administered lozenges with Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp. lactis BB-12 on the number of salivary mutans streptococci, amount of plaque, gingival inflammation and the oral microbiome in healthy adults.

    Science.gov (United States)

    Toiviainen, Aino; Jalasvuori, Heli; Lahti, Emilia; Gursoy, Ulvi; Salminen, Seppo; Fontana, Margherita; Flannagan, Susan; Eckert, George; Kokaras, Alexis; Paster, Bruce; Söderling, Eva

    2015-01-01

    The aim was to evaluate the effects of orally administered Lactobacillus rhamnosus GG (LGG) and Bifidobacterium animalis subsp. lactis BB-12 (BB-12) on the number of salivary mutans streptococci (MS), amount of plaque, gingival inflammation and the oral microbiota in healthy young adults. The study was a randomised, controlled, double-blind trial. Healthy volunteers used lozenges containing a combination of LGG and BB-12 (test group, n = 29) or lozenges without added probiotics (control group, n = 31) for 4 weeks. At baseline and at the end of the test period, the plaque index (PI) and gingival index (GI) were determined, and stimulated saliva was collected. The microbial composition of saliva was assessed using human oral microbe identification microarray (n = 30). MS and lactobacilli (LB) were plate cultured. The probiotic lozenge decreased both PI and GI (p < 0.05) while no changes were observed in the control group. However, no probiotic-induced changes were found in the microbial compositions of saliva in either group. The probiotic lozenge improved the periodontal status without affecting the oral microbiota. Short-term consumption of LGG and BB-12 decreased the amount of plaque which was associated with a clinical impact: a decrease in gingival inflammation.

  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. Effect of the probiotic strain Bifidobacterium animalis subsp. lactis, BB-12®, on defecation frequency in healthy subjects with low defecation frequency and abdominal discomfort: a randomised, double-blind, placebo-controlled, parallel-group trial.

    Science.gov (United States)

    Eskesen, Dorte; Jespersen, Lillian; Michelsen, Birgit; Whorwell, Peter J; Müller-Lissner, Stefan; Morberg, Cathrine M

    2015-11-28

    The aim of the present study was to investigate the effect of Bifidobacterium animalis subsp. lactis, BB-12®, on two primary end points - defecation frequency and gastrointestinal (GI) well-being - in healthy adults with low defecation frequency and abdominal discomfort. A total of 1248 subjects were included in a randomised, double-blind, placebo-controlled trial. After a 2-week run-in period, subjects were randomised to 1 or 10 billion colony-forming units/d of the probiotic strain BB-12® or a matching placebo capsule once daily for 4 weeks. Subjects completed a diary on bowel habits, relief of abdominal discomfort and symptoms. GI well-being, defined as global relief of abdominal discomfort, did not show significant differences. The OR for having a defecation frequency above baseline for ≥50% of the time was 1·31 (95% CI 0·98, 1·75), P=0·071, for probiotic treatment overall. Tightening the criteria for being a responder to an increase of ≥1 d/week for ≥50 % of the time resulted in an OR of 1·55 (95% CI 1·22, 1·96), P=0·0003, for treatment overall. A treatment effect on average defecation frequency was found (P=0·0065), with the frequency being significantly higher compared with placebo at all weeks for probiotic treatment overall (all Pprobiotic strain BB-12® resulted in a clinically relevant benefit on defecation frequency. The results suggest that consumption of BB-12® improves the GI health of individuals whose symptoms are not sufficiently severe to consult a doctor (ISRCTN18128385).

  11. Xylo-oligosaccharides alone or in synbiotic combination with Bifidobacterium animalis subsp. lactis induce bifidogenesis and modulate markers of immune function in healthy adults: a double-blind, placebo-controlled, randomised, factorial cross-over study.

    Science.gov (United States)

    Childs, Caroline E; Röytiö, Henna; Alhoniemi, Esa; Fekete, Agnes A; Forssten, Sofia D; Hudjec, Natasa; Lim, Ying Ni; Steger, Cara J; Yaqoob, Parveen; Tuohy, Kieran M; Rastall, Robert A; Ouwehand, Arthur C; Gibson, Glenn R

    2014-06-14

    Prebiotics, probiotics and synbiotics are dietary ingredients with the potential to influence health and mucosal and systemic immune function by altering the composition of the gut microbiota. In the present study, a candidate prebiotic (xylo-oligosaccharide, XOS, 8 g/d), probiotic (Bifidobacterium animalis subsp. lactis Bi-07, 109 colony-forming units (CFU)/d) or synbiotic (8 g XOS+109 CFU Bi-07/d) was given to healthy adults (25-65 years) for 21 d. The aim was to identify the effect of the supplements on bowel habits, self-reported mood, composition of the gut microbiota, blood lipid concentrations and immune function. XOS supplementation increased mean bowel movements per d (P= 0·009), but did not alter the symptoms of bloating, abdominal pain or flatulence or the incidence of any reported adverse events compared with maltodextrin supplementation. XOS supplementation significantly increased participant-reported vitality (P= 0·003) and happiness (P= 0·034). Lowest reported use of analgesics was observed during the XOS+Bi-07 supplementation period (P= 0·004). XOS supplementation significantly increased faecal bifidobacterial counts (P= 0·008) and fasting plasma HDL concentrations (P= 0·005). Bi-07 supplementation significantly increased faecal B. lactis content (P= 0·007), lowered lipopolysaccharide-stimulated IL-4 secretion in whole-blood cultures (P= 0·035) and salivary IgA content (P= 0·040) and increased IL-6 secretion (P= 0·009). XOS supplementation resulted in lower expression of CD16/56 on natural killer T cells (P= 0·027) and lower IL-10 secretion (P= 0·049), while XOS and Bi-07 supplementation reduced the expression of CD19 on B cells (XOS × Bi-07, P= 0·009). The present study demonstrates that XOS induce bifidogenesis, improve aspects of the plasma lipid profile and modulate the markers of immune function in healthy adults. The provision of XOS+Bi-07 as a synbiotic may confer further benefits due to the discrete effects of Bi-07 on the gut

  12. Effects of Bifidobacterium animalis subsp. lactis BB-12®on the lipid/lipoprotein profile and short chain fatty acids in healthy young adults: a randomized controlled trial.

    Science.gov (United States)

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

    2017-06-29

    Some probiotics have hypocholesterolemic effects in animal studies, which are mediated, in part, by increases in fecal short chain fatty acids (SCFAs). Clinical trials of probiotics on lipids/lipoproteins are inconsistent. We examined the effects of Bifidobacterium animalis subsp. lactis BB-12 ® (BB-12 ® ) (3.16 × 10 9  CFUs/day) on lipids and lipoproteins and fecal excretion of SCFAs in healthy adults. In a randomized, partially blinded, 4-period, crossover study, 30 adults (11 men, 19 women) aged 18-40 years were randomly assigned to: 1) yogurt smoothie with no BB-12 ® (YS), 2) yogurt smoothie with BB-12 ® added pre-fermentation (PRE), 3) yogurt smoothie with BB-12 ® added post-fermentation (POST), 4) BB-12 ® containing capsule (CAP). We measured serum lipids/lipoproteins, glucose, insulin, C-reactive protein (CRP), and fecal SCFAs at baseline and after each treatment period. Total cholesterol (TC), LDL cholesterol (LDL-C), HDL cholesterol (HDL-C), and triglycerides (TGs) did not differ after the PRE, POST, and CAP periods versus the YS or between treatments. Compared to baseline, fecal acetate was significantly increased after the YS (Δ = 211.89 ± 75.87 μg/g, P = 0.007) and PRE (Δ = 204.98 ± 75.70 μg/g, P = 0.009) periods. The percent increase in fecal acetate was significantly greater after the YS versus the POST period (52.2 ± 13.2% vs. 24.5 ± 13.2%, P = 0.023). Fecal total SCFAs, propionate and butyrate did not differ between treatment periods. Fecal total SCFAs were negatively associated with TC (r = -0.22, P = 0.01), LDL-C (r = -0.24, P = 0.004), age (r = -0.33, P BB-12 ® supplementation did not improve lipids, lipoproteins and total and individual fecal SCFAs. Fecal SCFAs were negatively associated with TC, LDL-C, age, and waist circumference. This trial was registered at clinicaltrials.gov as NCT01399996 .

  13. 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.

  14. 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....

  15. 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.

  16. Microbiota of Minas cheese as influenced by the nisin producer Lactococcus lactis subsp. lactis GLc05.

    Science.gov (United States)

    Perin, Luana Martins; Dal Bello, Barbara; Belviso, Simona; Zeppa, Giuseppe; Carvalho, Antônio Fernandes de; Cocolin, Luca; Nero, Luís Augusto

    2015-12-02

    Minas cheese is a popular dairy product in Brazil that is traditionally produced using raw or pasteurized cow milk. This study proposed an alternative production of Minas cheese using raw goat milk added of a nisin producer Lactococcus lactis subsp. lactis GLc05. An in situ investigation was carried on to evaluate the interactions between the L. lactis subsp. lactis GLc05 and the autochthonous microbiota of a Minas cheese during the ripening; production of biogenic amines (BAs) was assessed as a safety aspect. Minas cheese was produced in two treatments (A, by adding L. lactis subsp. lactis GLc05, and B, without adding this strain), in three independent repetitions (R1, R2, and R3). Culture dependent (direct plating) and independent (rep-PCR and PCR-DGGE) methods were employed to characterize the microbiota and to assess the possible interferences caused by L. lactis subsp. lactis GLc05. BA amounts were measured using HPLC. A significant decrease in coagulase-positive cocci was observed in the cheeses produced by adding L. lactis subsp. lactis GLc05 (cheese A). The rep-PCR and PCR-DGGE highlighted the differences in the microbiota of both cheeses, separating them into two different clusters. Lactococcus sp. was found as the main microorganism in both cheeses, and the microbiota of cheese A presented a higher number of species. High concentrations of tyramine were found in both cheeses and, at specific ripening times, the BA amounts in cheese B were significantly higher than in cheese A (pcheese and by controlling the growth of coagulase-positive cocci. L. lactis subsp. lactis GLc05 influenced also the production of BA determining that their amounts in the cheeses were maintained at acceptable levels for human consumption. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. 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...

  18. 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

  19. 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.

    1999-01-01

    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

  20. 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 ...

  1. 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

  2. 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

  3. 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.

  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. Molecular Analyses of the Lactococcin A Gene Cluster from Lactococcus lactis subsp. lactis Biovar Diacetylactis WM4

    NARCIS (Netherlands)

    Stoddard, Gary W.; Petzel, James P.; Belkum, Marco J. van; Kok, Jan; McKay, Larry L.

    1992-01-01

    The genes responsible for bacteriocin production and immunity in Lactococcus lactis subsp. lactis biovar diacetylactis WM4 were localized and characterized by DNA restriction fragment deletion, subcloning, and nucleotide sequence analysis. The nucleotide sequence of a 5.6-kb AvaII restriction

  6. MOLECULAR ANALYSES OF THE LACTOCOCCIN-A GENE-CLUSTER FROM LACTOCOCCUS-LACTIS SUBSP LACTIS BIOVAR DIACETYLACTIS WM4

    NARCIS (Netherlands)

    STODDARD, GW; PETZEL, JP; VANBELKUM, MJ; KOK, J; MCKAY, LL

    The genes responsible for bacteriocin production and immunity in Lactococcus lactis subsp. lactis biovar diacetylactis WM4 were localized and characterized by DNA restriction fragment deletion, subcloning, and nucleotide sequence analysis. The nucleotide sequence of a 5.6-kb AvaII restriction

  7. Heterologous Gene Expression in Lactococcus lactis subsp. lactis : Synthesis, Secretion, and Processing of the Bacillus subtilis Neutral Protease

    NARCIS (Netherlands)

    Guchte, Maarten van de; Kodde, Jan; Vossen, Jos M.B.M. van der; Kok, Jan; Venema, Gerard

    1990-01-01

    The Bacillus subtilis nprE gene lacking its own promoter sequence was inserted in the lactococcal expression vector pMG36e. Upon introduction of the recombinant plasmid into Lactococcus lactis subsp. lactis strain MG1363, neutral protease activity could be visualized by the appearance of large

  8. Potential probiotic Bifidobacterium animalis ssp. lactis 420 prevents weight gain and glucose intolerance in diet-induced obese mice.

    Science.gov (United States)

    Stenman, L K; Waget, A; Garret, C; Klopp, P; Burcelin, R; Lahtinen, S

    2014-12-01

    Alterations of the gut microbiota and mucosal barrier are linked with metabolic diseases. Our aim was to investigate the potential benefit of the potential probiotic Bifidobacterium animalis ssp. lactis 420 in reducing high-fat diet-induced body weight gain and diabetes in mice. In the obesity model, C57Bl/6J mice were fed a high-fat diet (60 energy %) for 12 weeks, and gavaged daily with B. lactis 420 (109 cfu) or vehicle. In the diabetes model, mice were fed a high-fat, ketogenic diet (72 energy % fat) for 4 weeks, with a 6-week subsequent treatment with B. lactis 420 (108-1010 cfu/day) or vehicle, after which they were analysed for body composition. We also analysed glucose tolerance, plasma lipopolysaccharide and target tissue inflammation using only one of the B. lactis 420 groups (109 cfu/day). Intestinal bacterial translocation and adhesion were analysed in a separate experiment using an Escherichia coli gavage. Body fat mass was increased in both obese (10.7 ± 0.8 g (mean ± standard error of mean) vs. 1.86 ± 0.21 g, Pdiabetic mice (3.01 ± 0.4 g vs. 1.14 ± 0.15 g, Pdiabetic mice (1.89 ± 0.16 g, P=0.02 for highest dose). This was reflected as reduced weight gain and improved glucose tolerance. Furthermore, B. lactis 420 decreased plasma lipopolysaccharide levels (Pdiabetic mice. Reduced intestinal mucosal adherence and plasma lipopolysaccharide suggest a mechanism related to reduced translocation of gut microbes.

  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 cheese manufacturing.

  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. 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. Complete genome sequence of the prototype lactic acid bacterium Lactococcus lactis subsp cremoris MG1363

    NARCIS (Netherlands)

    Wegmann, Udo; O'Connell-Motherwy, Mary; Zomer, Aldert; Buist, Girbe; Shearman, Claire; Canchaya, Carlos; Ventura, Marco; Goesmann, Alexander; Gasson, Michael J.; Kuipers, Oscar P.; van Sinderen, Douwe; Kok, Jan

    Lactococcus lactis is of great importance for the nutrition of hundreds of millions of people worldwide. This paper describes the genome sequence of Lactococcus lactis subsp. cremoris MG1363, the lactococcal strain most intensively studied throughout the world. The 2,529,478-bp genome contains 81

  13. 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

  14. Use of PCR-Based Methods for Rapid Differentiation of Lactobacillus delbrueckii subsp. bulgaricus and L. delbrueckii subsp. lactis

    Science.gov (United States)

    Torriani, Sandra; Zapparoli, Giacomo; Dellaglio, Franco

    1999-01-01

    Two PCR-based methods, specific PCR and randomly amplified polymorphic DNA PCR (RAPD-PCR), were used for rapid and reliable differentiation of Lactobacillus delbrueckii subsp. bulgaricus and L. delbrueckii subsp. lactis. PCR with a single combination of primers which targeted the proline iminopeptidase (pepIP) gene of L. delbrueckii subsp. bulgaricus allowed amplification of genomic fragments specific for the two subspecies when either DNA from a single colony or cells extracted from dairy products were used. A numerical analysis of the RAPD-PCR patterns obtained with primer M13 gave results that were consistent with the results of specific PCR for all strains except L. delbrueckii subsp. delbrueckii LMG 6412T, which clustered with L. delbrueckii subsp. lactis strains. In addition, RAPD-PCR performed with primer 1254 provided highly polymorphic profiles and thus was superior for distinguishing individual L. delbrueckii strains. PMID:10508059

  15. 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.

  16. 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.

  17. 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.

  18. 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....... At 5-degrees C in M17 broth, the organism grew well ans produced nisin. In an infusion of cold-smoked salmon the organism did not grow at 5-degrees C, althoigh it did at 10-degrees C. NACl up to 4% allowed for efficient growth and nisin production, while 5% NaCl resultes in very slow growth...

  19. Development of a growth medium suitable for exopolysaccharide production and structural characterisation by Bifidobacterium animalis ssp. lactis AD011.

    Science.gov (United States)

    Alhudhud, M; Humphreys, P; Laws, A

    2014-05-01

    Exopolysaccharides (EPSs) produced by Bifidobacteria have received considerable attention due to their ability to modify the rheological and physicochemical properties of dairy products. However, the quantification and characterisation of Bifidobacterial EPS are hampered by the presence of EPS-equivalent (EPS-E) substances in complex media such as Reinforced Clostridial Medium (RCM). This study has developed a medium based on RCM which both supports the growth of Bifidobacterium animalis ssp. lactis AD011 and does not interfere with the quantification and characterisation of the EPS generated. Medium development involved the identification of EPE-E containing components via NMR analysis followed by their removal, substitution or pre-treatment. Both beef extract and casein acid hydrolysate required chemical pre-treatment to remove polysaccharide components before the medium was free of EPS-E materials. Once EPS-E free components had been identified, lactose, glucose and galactose were evaluated as potential carbon sources. Glucose was found to be the optimum carbon source. The final medium composition supported growth to the same extent as RCM providing significant EPS yields and no interferences during analysis. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. 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

  1. 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...

  2. PURIFICATION AND CHARACTERIZATION OF AN ENDOPEPTIDASE FROM LACTOCOCCUS-LACTIS SUBSP CREMORIS WG2

    NARCIS (Netherlands)

    TAN, PST; POS, KM; KONINGS, WN

    1991-01-01

    An endopeptidase has been purified to homogeneity from a crude cell extract of Lactococcus lactis subsp. cremoris Wg2 by a procedure that includes diethyl-aminoethane-Sephacel chromatography, phenyl-Sepharose chromatography, hydroxylapatite chromatography, and fast protein liquid chromatography over

  3. 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

  4. 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...

  5. 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.

  6. 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

  7. 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.  

  8. 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.

  9. 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.

  10. 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...... orientations, which facilitates the optimization of interactions with the various ligands. Broad substrate specificity was further enhanced by a spacious binding pocket accommodating decorations at different mainchain positions and conformational flexibility of a lid‐like loop. Phylogenetic and genetic...

  11. Bifidobacterium animalis subsp lactis decreases urinary oxalate excretion in a mouse model of primary hyperoxaluria

    Czech Academy of Sciences Publication Activity Database

    Klimešová, Klára; Whittamore, J.M.; Hatch, M.

    2015-01-01

    Roč. 43, č. 2 (2015), s. 107-117 ISSN 2194-7228 Institutional support: RVO:61388971 Keywords : Probiotics * Oxalobacter formigenes * Hyperoxaluria Subject RIV: EE - Microbiology, Virology Impact factor: 1.454, year: 2015

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Transcription profiling of interactions between Lactococcus lactis subsp. cremoris SK11 and Lactobacillus paracasei ATCC 334 during Cheddar cheese simulation.

    Science.gov (United States)

    Desfossés-Foucault, Émilie; LaPointe, Gisèle; Roy, Denis

    2014-05-16

    The starter cultures (Lactococcus sp.) and non-starter lactic acid bacteria (mostly Lactobacillus spp.) are essential to flavor development of Cheddar cheese. The aim of this study was to elucidate the transcriptional interaction between Lactococcus lactis subsp. cremoris SK11 and Lactobacillus paracasei ATCC 334 in mixed cultures during simulated Cheddar cheese manufacture (Pearce activity test) and ripening (slurry). Reverse transcription quantitative PCR (RT-qPCR) was used to quantify the expression of 34 genes common to both bacteria and for eight genes specific to either L. lactis subsp. cremoris SK11 or L. paracasei ATCC 334. The multifactorial analysis (MFA) performed on fold change results for each gene revealed that the genes linked to stress, protein and peptide degradation as well as carbohydrate metabolism of L. paracasei ATCC 334 were especially overexpressed in mixed culture with L. lactis subsp. cremoris SK11 during the ripening simulation. For L. lactis subsp. cremoris SK11, genes coding for amino acid metabolism were more expressed during the cheese manufacture simulation, especially in single culture. These results show how complementary functions of starter and NSLAB contribute to activities useful for flavor development. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. 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.

  18. 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.

  19. Breastfeeding-associated microbiota in human milk following supplementation with Lactobacillus rhamnosus GG, Lactobacillus acidophilus La-5, and Bifidobacterium animalis ssp. lactis Bb-12.

    Science.gov (United States)

    Simpson, Melanie Rae; Avershina, Ekaterina; Storrø, Ola; Johnsen, Roar; Rudi, Knut; Øien, Torbjørn

    2018-02-01

    Breastfeeding is one of the major factors affecting the early development of the infant gut microbiota, and weaning is associated with a shift in the gut microbiota toward a more adult composition. Through breastfeeding, infants receive bioactive components that shape their microbiota while also being exposed to the breast milk and breast surface microbial communities. Recent studies have suggested the possibility of an entero-mammary route of microbial transfer, opening the possibility of infant gut microbiota modulation through maternal probiotic supplementation. In this study, we have analyzed breast milk samples collected at 10 d and 3 mo postpartum from women participating in the Probiotics in the Prevention of Allergy among Children in Trondheim placebo controlled trial. Women who were randomized to the probiotic arm of the Probiotics in the Prevention of Allergy among Children in Trondheim trial received a fermented milk supplemented with Lactobacillus rhamnosus GG, Lactobacillus acidophilus La-5, and Bifidobacterium animalis ssp. lactis Bb-12, consuming this daily from 4 wk before their expected due date until 3 mo after birth. In total, 472 breast milk samples were assessed for the administered bacteria using quantitative real-time PCR and the microbiota transferred during breastfeeding was analyzed using 16S ribosomal RNA gene sequencing of 142 samples. We found that breastfeeding is unlikely to be a significant source of L. rhamnosus GG, L. acidophilus La-5, and B. animalis ssp. lactis Bb-12 for infants in the probiotic arm of the trial. Furthermore, maternal supplementation did not significantly affect the overall composition of the breast milk microbiota transferred during breastfeeding. We also present a descriptive analysis of this microbiota, which was largely dominated by Streptococcus and Staphylococcus genera at both 10 d and 3 mo postpartum. Samples collected at 3 mo postpartum had a statistically significant lower presence and relative

  20. 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.

  1. 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.

  2. Transcriptional responses in Lactococcus lactis subsp. cremoris to the changes in oxygen and redox potential during milk acidification

    DEFF Research Database (Denmark)

    Larsen, Nadja; Werner, Birgit Brøsted; Jespersen, Lene

    2016-01-01

    is important for the better control and reproducibility of dairy fermentations. We applied mRNA sequencing by Illumina HiSeq 2000 to investigate gene expression profile in a dairy strain of Lactococcus lactis subsp. cremoris during milk acidification. Novelty of this study lies in linking transcriptional...... responses to oxygen depletion and the changes of redox potential with the fermentation kinetics and clarification of molecular factors specifically expressed in milk which might be essential for bacterial performance and the final quality of cheeses.......Milk acidification and metabolic activity of the starter cultures are affected by oxygen; however, molecular factors related to the redox changes are poorly defined. The objective of the study was to investigate transcriptional responses in Lactococcus lactis subsp. cremoris CHCCO2 grown in milk...

  3. Effect of Lactobacillus rhamnosus LGG® and Bifidobacterium animalis ssp. lactis BB-12® on health-related quality of life in college students affected by upper respiratory infections.

    Science.gov (United States)

    Smith, Tracey J; Rigassio-Radler, Diane; Denmark, Robert; Haley, Timothy; Touger-Decker, Riva

    2013-06-01

    College students are susceptible to upper respiratory infections (URI) due to inadequate sleep, stress and close living quarters. Certain probiotic strains modulate immune function and may improve health-related quality of life (HRQL) during URI. The present study recruited apparently healthy college students and assessed the effect of probiotics on HRQL outcomes (i.e. self-reported duration, symptom severity and functional impairment of URI) in those who developed URI. Missed school and work days due to URI were also considered. Subjects (n 231) were apparently healthy college students living on campus in residence halls at the Framingham State University (Framingham, MA, USA), and were randomised to receive placebo (n 117) or probiotic-containing powder (daily dose of minimum 1 billion colony-forming units of each Lactobacillus rhamnosus LGG® (LGG®) and Bifidobacterium animalis ssp. lactis BB-12® (BB-12®); n 114) for 12 weeks. Subjects completed The Wisconsin Upper Respiratory Symptom Survey-21 to assess HRQL during URI. The final analyses included 198 subjects (placebo, n 97 and probiotics, n 101). The median duration of URI was significantly shorter by 2 d and median severity score was significantly lower by 34% with probiotics v. placebo (P,0·001), indicating a higher HRQL during URI. Number of missed work days was not different between groups (P=0·429); however, the probiotics group missed significantly fewer school days (mean difference = 0·2 d) compared to the placebo group (P=0·002). LGG® and BB-12® may be beneficial among college students with URI for mitigating decrements in HRQL. More research is warranted regarding mechanisms of action associated with these findings and the cost-benefit of prophylactic supplementation.

  4. Short-term, daily intake of yogurt containing Bifidobacterium animalis ssp. lactis Bf-6 (LMG 24384) does not affect colonic transit time in women.

    Science.gov (United States)

    Merenstein, Daniel J; D'Amico, Frank; Palese, Caren; Hahn, Alexander; Sparenborg, Jessy; Tan, Tina; Scott, Hillary; Polzin, Kayla; Kolberg, Lore; Roberts, Robert

    2014-01-28

    The present study investigated the effect of Bifidobacterium animalis ssp. lactis Bf-6 (LMG 24 384) (Bf-6)-supplemented yogurt on colonic transit time (CTT). A triple-blinded, randomised, placebo-controlled, two-period cross-over trial was conducted with sixty-eight women with a self-reported history of straining during bowel movements or hard or lumpy stools in the past 2 years. As per regulatory requirements for probiotic studies, eligible women were generally healthy and not actively constipated at the time of enrolment. Participants consumed both Bf-6 and placebo yogurts for 14 d each in a randomised order, with a 6-week washout period between the treatments. The primary outcome, CTT, was assessed via Sitz marker X-rays. The average CTT was 42·1 h for the active period and 43·3 h for the control period (mean difference 1·2 h, 95 % CI - 4·9, 7·4). Since the statistical tests for the cross-over study implied that the mean CTT for the active and control periods in period 2 were biased, the standard protocol suggests examining the results of only period 1 as a traditional randomised controlled trial. This showed that the mean CTT was 35·2 h for the active period v. 52·9 h for the control period (P= 0·015). Bootstrapping demonstrated that both the mean and median differences remained significant (P= 0·016 and P= 0·045, respectively). Few adverse events were noted, with no differences among the active and control periods. The paired analysis showed no differences between the active and control periods during the cross-over trial. Further trials should be conducted in populations with underlying problems associated with disordered transit to determine the potential value of probiotic supplementation more accurately.

  5. AbiV, a Novel Antiphage Abortive Infection Mechanism on the Chromosome of Lactococcus lactis subsp. cremoris MG1363

    DEFF Research Database (Denmark)

    Haaber, Jakob Brandt Borup; Moineau, Sylvain; Fortier, Louis-Charles

    2008-01-01

    Insertional mutagenesis with pGhost9::ISS1 resulted in independent insertions in a 350-bp region of the chromosome of Lactococcus lactis subsp. cremoris MG1363 that conferred phage resistance to the integrants. The orientation and location of the insertions suggested that the phage resistance...... phenotype was caused by a chromosomal gene turned on by a promoter from the inserted construct. Reverse transcription-PCR analysis confirmed that there were higher levels of transcription of a downstream open reading frame (ORF) in the phage-resistant integrants than in the phage-sensitive strain L. lactis...... resistance against virulent lactococcal phages belonging to the 936 and c2 species with an efficiency of plaquing of 10(-4), but it did not protect against members of the P335 species. A high level of expression of the ORF did not affect the cellular growth rate. Assays for phage adsorption, DNA ejection...

  6. 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

  7. 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...... 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......, or immunomodulation of the host immune system. The identification of proteins predicted to be involved in such interactions can pave the way towards well targeted studies of the protein‐mediated contacts between bacteria and the host, with the goal to enhance the understanding of the mode of action of probiotic...

  8. 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.

  9. The distinct effects of orally administered Lactobacillus rhamnosus GG and Lactococcus lactis subsp. lactis C59 on gene expression in the murine small intestine.

    Directory of Open Access Journals (Sweden)

    Chise Suzuki

    Full Text Available The molecular mechanisms of strain-specific probiotic effects and the impact of the oral administration of probiotic strains on the host's gene expression are not yet well understood. The aim of this study was to investigate the strain-specific effects of probiotic strain intake on gene expression in the murine small intestine. Two distinct strains of lactic acid bacteria, Lactobacillus rhamnosus GG (GG and Lactococcus lactis subsp. lactis C59 (C59, were orally administered to BALB/c mice, daily for 2 weeks. The total RNA was isolated from the upper (including the duodenum and lower (the terminal ileum small intestine, and gene expression was assessed by microarray analysis. The data revealed (1 oral administration of C59 and GG markedly down-regulated the expression of genes encoding fibrinogen subunits and plasminogen in the upper small intestine; (2 administration of more than 1 × 107 CFU/day of GG changed the gene expression of the host ileum. (3 strain- and dose-related effects on various GO biological processes; and (4 enrichment for B cell-related Gene Ontology terms among up-regulated genes in the terminal ileum of mice administered the 1 × 109 CFU/day of GG. The distinct effects of GG and C59 on gene expression in the intact small intestine provide clues to understand how the health beneficial effects of specific strains of probiotic bacteria are mediated by interactions with intestinal cells.

  10. The distinct effects of orally administered Lactobacillus rhamnosus GG and Lactococcus lactis subsp. lactis C59 on gene expression in the murine small intestine

    Science.gov (United States)

    Aoki-Yoshida, Ayako; Aoki, Reiji; Sasaki, Keisuke; Takayama, Yoshiharu; Mizumachi, Koko

    2017-01-01

    The molecular mechanisms of strain-specific probiotic effects and the impact of the oral administration of probiotic strains on the host’s gene expression are not yet well understood. The aim of this study was to investigate the strain-specific effects of probiotic strain intake on gene expression in the murine small intestine. Two distinct strains of lactic acid bacteria, Lactobacillus rhamnosus GG (GG) and Lactococcus lactis subsp. lactis C59 (C59), were orally administered to BALB/c mice, daily for 2 weeks. The total RNA was isolated from the upper (including the duodenum) and lower (the terminal ileum) small intestine, and gene expression was assessed by microarray analysis. The data revealed (1) oral administration of C59 and GG markedly down-regulated the expression of genes encoding fibrinogen subunits and plasminogen in the upper small intestine; (2) administration of more than 1 × 107 CFU/day of GG changed the gene expression of the host ileum. (3) strain- and dose-related effects on various GO biological processes; and (4) enrichment for B cell-related Gene Ontology terms among up-regulated genes in the terminal ileum of mice administered the 1 × 109 CFU/day of GG. The distinct effects of GG and C59 on gene expression in the intact small intestine provide clues to understand how the health beneficial effects of specific strains of probiotic bacteria are mediated by interactions with intestinal cells. PMID:29220366

  11. The distinct effects of orally administered Lactobacillus rhamnosus GG and Lactococcus lactis subsp. lactis C59 on gene expression in the murine small intestine.

    Science.gov (United States)

    Suzuki, Chise; Aoki-Yoshida, Ayako; Aoki, Reiji; Sasaki, Keisuke; Takayama, Yoshiharu; Mizumachi, Koko

    2017-01-01

    The molecular mechanisms of strain-specific probiotic effects and the impact of the oral administration of probiotic strains on the host's gene expression are not yet well understood. The aim of this study was to investigate the strain-specific effects of probiotic strain intake on gene expression in the murine small intestine. Two distinct strains of lactic acid bacteria, Lactobacillus rhamnosus GG (GG) and Lactococcus lactis subsp. lactis C59 (C59), were orally administered to BALB/c mice, daily for 2 weeks. The total RNA was isolated from the upper (including the duodenum) and lower (the terminal ileum) small intestine, and gene expression was assessed by microarray analysis. The data revealed (1) oral administration of C59 and GG markedly down-regulated the expression of genes encoding fibrinogen subunits and plasminogen in the upper small intestine; (2) administration of more than 1 × 107 CFU/day of GG changed the gene expression of the host ileum. (3) strain- and dose-related effects on various GO biological processes; and (4) enrichment for B cell-related Gene Ontology terms among up-regulated genes in the terminal ileum of mice administered the 1 × 109 CFU/day of GG. The distinct effects of GG and C59 on gene expression in the intact small intestine provide clues to understand how the health beneficial effects of specific strains of probiotic bacteria are mediated by interactions with intestinal cells.

  12. Proteolysis in Hispánico cheese manufactured using a mesophilic starter, a thermophilic starter, and bacteriocin-producing Lactococcus lactis subsp. lactis INIA 415 adjunct culture.

    Science.gov (United States)

    Garde, Sonia; Tomillo, Javier; Gaya, Pilar; Medina, Margarita; Nuñez, Manuel

    2002-06-05

    Lactococcus lactis subsp. lactis INIA 415, a strain harboring the structural genes of bacteriocins nisin Z and lacticin 481, was used as adjunct culture in the manufacture of Hispánico cheese with a mesophilic starter and a thermophilic starter of high aminopeptidase activity. Addition of the bacteriocin producer promoted early lysis of mesophilic and thermophilic starter bacteria. Extracellular aminopeptidase activity in 7-day-old cheese made using mesophilic and thermophilic starters plus bacteriocin producer was 3.0-fold the level reached in cheese made without the bacteriocin producer. Proteolysis in cheese made with mesophilic and thermophilic starters plus bacteriocin-producing adjunct culture after 25 days of ripening was 1.5-fold the level reached in cheese made without the bacteriocin producer, and the level of total free amino acids was 2.9-fold the level found in cheese made without the bacteriocin producer. Cheese made with mesophilic and thermophilic starters plus bacteriocin producer received the highest scores for flavor quality and flavor intensity and reached in 25 days the flavor intensity score of a 75-day-old cheese made without the bacteriocin producer.

  13. 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

  14. DEGRADATION AND DEBITTERING OF A TRYPTIC DIGEST FROM BETA-CASEIN BY AMINOPEPTIDASE-N FROM LACTOCOCCUS-LACTIS SUBSP CREMORIS WG2

    NARCIS (Netherlands)

    TAN, PST; VANKESSEL, TAJM; VANDEVEERDONK, FLM; ZUURENDONK, PF; BRUINS, AP; KONINGS, WN

    The mode of action of purified aminopeptidase N from Lactococcus lactis subsp. cremoris Wg2 on a complex peptide mixture of a tryptic digest from bovine beta-casein was analyzed. The oligopeptides produced in the tryptic digest before and after aminopeptidase N treatment were identified by analysis

  15. Cloning and characterization of brnQ, a gene encoding a low-affinity, branched chain amino acid carrier in Lactobacillus delbruckii subsp lactis DSM7290

    NARCIS (Netherlands)

    Stucky, K; Hagting, A; Klein, J.R.; Matern, H; Henrich, B; Konings, WN; Plapp, R

    1995-01-01

    A gene (brnQ), encoding a carrier for branched-chain amino acids in Lactobacillus delbruckii subsp. lactis DSM7290 was cloned in the low-copy-number vector pLG339 by complementation of a transport-deficient Escherichia coli strain. The plasmid carrying the cloned gene restored growth of an E. coli

  16. Isolation, taxonomic identification and hydrogen peroxide production by Lactobacillus delbrueckii subsp. lactis T31, isolated from Mongolian yoghurt: inhibitory activity on food-borne pathogens.

    Science.gov (United States)

    Batdorj, B; Trinetta, V; Dalgalarrondo, M; Prévost, H; Dousset, X; Ivanova, I; Haertlé, T; Chobert, J-M

    2007-09-01

    The aim of this work was to isolate lactic acid bacteria (LAB) strains from Mongolian tarag (a traditionally homemade yoghurt) displaying antimicrobial activities against food-borne pathogens, identify inhibitory substances and study the kinetics of their production. Inhibitory substance-producing bacterial strains were isolated from tarag. From 300 bacterial clones, 31 were able to inhibit the growth of the indicator strain Lactobacillus bulgaricus 340. One of the most active strains was identified as Lactobacillus delbrueckii subsp. lactis strain T31 by using cluster analysis of amplified fragment length polymorphism (AFLP) DNA fingerprints. The antimicrobial substance was inactivated by catalase, demonstrating the production of hydrogen peroxide (H(2)O(2)). Production of H(2)O(2) was studied under aerated and nonaerated culture conditions. The amount of H(2)O(2) in the culture supernatant increased during bacterial growth and reached a maximum (5.12 mmol l(-1)) at the early stationary phase under aerated conditions (agitated cultures). H(2)O(2) was not detected in the culture performed without agitation. In mixed cultures performed in milk with either Lact. delbrueckii subsp. lactis T31 in the presence of Escherichia coli, or Lact. delbrueckii subsp. lactis T31 in the presence of Listeria innocua under aerated and nonaerated conditions, a significant decrease in pathogen count was observed in aerated cultures. The significant decrease in Listeria viability observed in aerated mixed cultures of Lact. delbrueckii subsp. lactis T31 is mainly because of H(2)O(2) production. Lactobacillus delbrueckii subsp. lactis T31 could be used as a protective culture in food industries or as a probiotic to prevent intestinal and urogenital infections.

  17. Effects of Roundup(®) and glyphosate on three food microorganisms: Geotrichum candidum, Lactococcus lactis subsp. cremoris and Lactobacillus delbrueckii subsp. bulgaricus.

    Science.gov (United States)

    Clair, Emilie; Linn, Laura; Travert, Carine; Amiel, Caroline; Séralini, Gilles-Eric; Panoff, Jean-Michel

    2012-05-01

    Use of many pesticide products poses the problem of their effects on environment and health. Amongst them, the effects of glyphosate with its adjuvants and its by-products are regularly discussed. The aim of the present study was to shed light on the real impact on biodiversity and ecosystems of Roundup(®), a major herbicide used worldwide, and the glyphosate it contains, by the study of their effects on growth and viability of microbial models, namely, on three food microorganisms (Geotrichum candidum, Lactococcus lactis subsp. cremoris and Lactobacillus delbrueckii subsp. bulgaricus) widely used as starters in traditional and industrial dairy technologies. The presented results evidence that Roundup(®) has an inhibitory effect on microbial growth and a microbicide effect at lower concentrations than those recommended in agriculture. Interestingly, glyphosate at these levels has no significant effect on the three studied microorganisms. Our work is consistent with previous studies which demonstrated that the toxic effect of glyphosate was amplified by its formulation adjuvants on different human cells and other eukaryotic models. Moreover, these results should be considered in the understanding of the loss of microbiodiversity and microbial concentration observed in raw milk for many years.

  18. Licheniocin 50.2 and Bacteriocins from Lactococcus lactis subsp. lactis biovar. diacetylactis BGBU1-4 Inhibit Biofilms of Coagulase Negative Staphylococci and Listeria monocytogenes Clinical Isolates.

    Science.gov (United States)

    Cirkovic, Ivana; Bozic, Dragana D; Draganic, Veselin; Lozo, Jelena; Beric, Tanja; Kojic, Milan; Arsic, Biljana; Garalejic, Eliana; Djukic, Slobodanka; Stankovic, Slavisa

    2016-01-01

    Coagulase negative staphylococci (CoNS) and Listeria monocytogenes have important roles in pathogenesis of various genital tract infections and fatal foetomaternal infections, respectively. The aim of our study was to investigate the inhibitory effects of two novel bacteriocins on biofilms of CoNS and L. monocytogenes genital isolates. The effects of licheniocin 50.2 from Bacillus licheniformis VPS50.2 and crude extract of bacteriocins produced by Lactococcus lactis subsp. lactis biovar. diacetylactis BGBU1-4 (BGBU1-4 crude extract) were evaluated on biofilm formation and formed biofilms of eight CoNS (four S. epidermidis, two S. hominis, one S. lugdunensis and one S. haemolyticus) and 12 L. monocytogenes genital isolates. Licheniocin 50.2 and BGBU1-4 crude extract inhibited the growth of both CoNS and L. monocytogenes isolates, with MIC values in the range between 200-400 AU/ml for licheniocin 50.2 and 400-3200 AU/ml for BGBU1-4 crude extract. Subinhibitory concentrations (1/2 × and 1/4 × MIC) of licheniocin 50.2 inhibited biofilm formation by all CoNS isolates (p < 0.05, respectively), while BGBU1-4 crude extract inhibited biofilm formation by all L. monocytogenes isolates (p < 0.01 and p < 0.05, respectively). Both bacteriocins in concentrations of 100 AU/mL and 200 AU/mL reduced the amount of 24 h old CoNS and L. monocytogenes biofilms (p < 0.05, p < 0.01, p < 0.001). This study suggests that novel bacteriocins have potential to be used for genital application, to prevent biofilm formation and/or to eradicate formed biofilms, and consequently reduce genital and neonatal infections by CoNS and L. monocytogenes.

  19. 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)

    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 ...

  20. Beneficial effects of fermented camel milk by lactococcus lactis subsp cremoris on cardiotoxicity induced by carbon tetrachloride in mice.

    Science.gov (United States)

    Hamed, Houda; Chaari, Fatma; Ghannoudi, Zied; ElFeki, Abdelfattah; Ellouz, Semia Chaabouni; Gargouri, Ahmed

    2018-01-01

    Carbon tetrachloride (CCl 4 ) is a xenobiotic present in the environment, can cause harmful effects on human health. In the present study, we attempted to elucidate the cardiopreventive potential of the fermented camel milk by lactococcus lactis subsp cremoris (FCM-LLC) against the toxic effects of acute exposure to CCl 4 on heart tissue of mice. Twenty-eight mice's were divided into four groups of seven each: group (C) served as control; group (FCM-LLC) received only 100mgL of FCM-LLC/kg body weight daily for 15days; group (CCl 4 ) was administered by a single dose of CCl 4 (10mL/kg in 0.3% olive oil, i.p) at day 14 and group (FCM-LLC+CCl 4 ) pretreated with FCM-LLC and received a single dose of CCl 4 on day 14. The exposure to a single dose of CCl 4 caused cardiotoxicity expressed by an increase in lipid peroxidation (TBARS), protein carbonyls (PC) levels and in antioxidant markers (superoxide dismutase (SOD), catalase (CAT), gluthathione peroxidase (GPx), glutathione (GSH) and Vitamin C levels) in the CCl 4 -treated group when compared with the untreated group. Furthermore, treatment with CCl 4 significantly elevated the cardiac toxicity markers while increasing of alanine aminotransferase (ALT), lactate dehydrogenase (LDH), creatine kinase (CK), creatine kinase MB (CKMB) and Troponin I activities. The pre-treatment of experimental mice's with FCM-LLC has allowed an improvement through lowering oxidative stress and attenuating cardiac toxicity. These modifications were further evident through histopathological aspects of the heart. Overall, the present data provide evidence of the beneficial effects of fermented camel milk by lactococcus lactis subsp creemoris clearly revealed through the reduction of the CCl 4 induced heart oxidative damages. Copyright © 2017. Published by Elsevier Masson SAS.

  1. 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.

  2. Cyclopropanation of membrane unsaturated fatty acids is not essential to the acid stress response of Lactococcus lactis subsp. cremoris.

    Science.gov (United States)

    To, Thi Mai Huong; Grandvalet, Cosette; Tourdot-Maréchal, Raphaëlle

    2011-05-01

    Cyclopropane fatty acids (CFAs) are synthetized in situ by the transfer of a methylene group from S-adenosyl-L-methionine to a double bond of unsaturated fatty acid chains of membrane phospholipids. This conversion, catalyzed by the Cfa synthase enzyme, occurs in many bacteria and is recognized to play a key role in the adaptation of bacteria in response to a drastic perturbation of the environment. The role of CFAs in the acid tolerance response was investigated in the lactic acid bacterium Lactococcus lactis MG1363. A mutant of the cfa gene was constructed by allelic exchange. The cfa gene encoding the Cfa synthase was cloned and introduced into the mutant to obtain the complemented strain for homologous system studies. Data obtained by gas chromatography (GC) and GC-mass spectrometry (GC-MS) validated that the mutant could not produce CFA. The CFA levels in both the wild-type and complemented strains increased upon their entry to stationary phase, especially with acid-adapted cells or, more surprisingly, with ethanol-adapted cells. The results obtained by performing quantitative reverse transcription-PCR (qRT-PCR) experiments showed that transcription of the cfa gene was highly induced by acidity (by 10-fold with cells grown at pH 5.0) and by ethanol (by 9-fold with cells grown with 6% ethanol) in comparison with that in stationary phase. Cell viability experiments were performed after an acidic shock on the mutant strain, the wild-type strain, and the complemented strain, as a control. The higher viability level of the acid-adapted cells of the three strains after 3 h of shock proved that the cyclopropanation of unsaturated fatty acids is not essential for L. lactis subsp. cremoris survival under acidic conditions. Moreover, fluorescence anisotropy data showed that CFA itself could not maintain the membrane fluidity level, particularly with ethanol-grown cells.

  3. Cyclopropanation of Membrane Unsaturated Fatty Acids Is Not Essential to the Acid Stress Response of Lactococcus lactis subsp. cremoris ▿

    Science.gov (United States)

    To, Thi Mai Huong; Grandvalet, Cosette; Tourdot-Maréchal, Raphaëlle

    2011-01-01

    Cyclopropane fatty acids (CFAs) are synthetized in situ by the transfer of a methylene group from S-adenosyl-l-methionine to a double bond of unsaturated fatty acid chains of membrane phospholipids. This conversion, catalyzed by the Cfa synthase enzyme, occurs in many bacteria and is recognized to play a key role in the adaptation of bacteria in response to a drastic perturbation of the environment. The role of CFAs in the acid tolerance response was investigated in the lactic acid bacterium Lactococcus lactis MG1363. A mutant of the cfa gene was constructed by allelic exchange. The cfa gene encoding the Cfa synthase was cloned and introduced into the mutant to obtain the complemented strain for homologous system studies. Data obtained by gas chromatography (GC) and GC-mass spectrometry (GC-MS) validated that the mutant could not produce CFA. The CFA levels in both the wild-type and complemented strains increased upon their entry to stationary phase, especially with acid-adapted cells or, more surprisingly, with ethanol-adapted cells. The results obtained by performing quantitative reverse transcription-PCR (qRT-PCR) experiments showed that transcription of the cfa gene was highly induced by acidity (by 10-fold with cells grown at pH 5.0) and by ethanol (by 9-fold with cells grown with 6% ethanol) in comparison with that in stationary phase. Cell viability experiments were performed after an acidic shock on the mutant strain, the wild-type strain, and the complemented strain, as a control. The higher viability level of the acid-adapted cells of the three strains after 3 h of shock proved that the cyclopropanation of unsaturated fatty acids is not essential for L. lactis subsp. cremoris survival under acidic conditions. Moreover, fluorescence anisotropy data showed that CFA itself could not maintain the membrane fluidity level, particularly with ethanol-grown cells. PMID:21421775

  4. Development of a pentaplex PCR assay for the simultaneous detection of Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, L. delbrueckii subsp. lactis, L. helveticus, L. fermentum in whey starter for Grana Padano cheese.

    Science.gov (United States)

    Cremonesi, Paola; Vanoni, Laura; Morandi, Stefano; Silvetti, Tiziana; Castiglioni, Bianca; Brasca, Milena

    2011-03-30

    A pentaplex PCR assay for the rapid, selective and simultaneous detection of Lactobacillus helveticus, L. delbrueckii subsp. lactis, L. delbrueckii subsp. bulgaricus, Streptococcus thermophilus, and L. fermentum, was developed. The target sequences were a group of genes coding for beta-galactosidase production (S. thermophilus and L. delbrueckii subsp. bulgaricus), for cell-enveloped associated proteinase synthesis (L. helveticus), for dipeptide transport system production (L. delbrueckii subsp. lactis) and for arginine-ornithine antiporter protein production (L. fermentum). The analytical specificity of the assay was evaluated with 5 reference strains and 140 lactic acid bacterial strains derived from raw milk cheeses and belonging to the Lactobacillus, Streptococcus, Lactococcus and Enterococcus genera. The identification limit for each target strain was 10(3)CFU/ml. This new molecular assay was used to investigate the LAB population by direct extraction of DNA from the 12 whey cultures for Grana Padano. The pentaplex PCR assay revealed a good correspondence with microbiological analyses and allowed to identify even minor LAB community members which, can be out-competed in vitro by numerically more abundant microbial species. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. 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.

  6. 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......, fundamental differences were observed between the pathogenic and probiotic treatments in the Toll-like receptor pathway, especially for adapter molecules with a lowered level of transcriptional activation of MyD88, TRIF, IRAK1 and TRAF6 by probiotics compared to EHEC. The results in this study provide...

  7. Isolation, cloning and characterisation of the abiI gene from Lactococcus lactis subsp. lactis M138 encoding abortive phage infection

    Science.gov (United States)

    Su, Ping; Harvey, Melissa; Im, Hee J.

    2010-01-01

    Plasmid pND852 (56 kb) encodes nisin resistance and was isolated from Lactococcus lactis ssp lactis (L. lactis) M138 by conjugation to L. lactis LM0230. It conferred strong resistance to the isometric-headed phage φ712 and partial resistance to the prolate-headed phage φc2. A 2.6 kb HpaII fragment encoding phage resistance was cloned into the streptococcal/Bacillus hybrid vector pGB301 to generate pND817. The mechanism of phage resistance encoded by pND817 involved abortive infection and this was illustrated by a reduction in burst size from 166 to 6 at 30°C and from 160 to 90 at 37°C. Partial resistance was therefore retained at 37°C. DNA sequencing revealed that the abortive infection was encoded by a single open reading frame (ORF), designated abiI, encoding a 332 amino acid protein. Neither abiI nor the predicted product showed significant homology to any existing sequence in the GenBank database. Frame shift mutation at the unique EcoRI site within the ORF resulted in loss of the Abi+ phenotype, confirming that the ORF is responsible for the encoded phage resistance. PMID:9195753

  8. Cyclopropanation of unsaturated fatty acids and membrane rigidification improve the freeze-drying resistance of Lactococcus lactis subsp. lactis TOMSC161.

    Science.gov (United States)

    Velly, H; Bouix, M; Passot, S; Penicaud, C; Beinsteiner, H; Ghorbal, S; Lieben, P; Fonseca, F

    2015-01-01

    This work aimed at characterizing the biochemical and biophysical properties of the membrane of Lactococcus lactis TOMSC161 cells during fermentation at different temperatures, in relation to their freeze-drying and storage resistance. Cells were cultivated at two different temperatures (22 and 30 °C) and were harvested at different growth phases (from the middle exponential phase to the late stationary phase). Bacterial membranes were characterized by determining the fatty acid composition, the lipid phase transition, and the membrane fluidity. Cultivability and acidification activity losses of L. lactis were quantified after freezing, drying, and 3 months of storage. The direct measurement of membrane fluidity by fluorescence anisotropy was linked to lipid composition, and it was established that the cyclopropanation of unsaturated fatty acids with concomitant membrane rigidification during growth led to an increase in the freeze-drying and storage resistance of L. lactis. As expected, cultivating cells at a lower fermentation temperature than the optimum growth temperature induced a homeoviscous adaptation that was demonstrated by a lowered lipid phase transition temperature but that was not related to any improvement in freeze-drying resistance. L. lactis TOMSC161 was therefore able to develop a combined biochemical and biophysical response at the membrane level during fermentation. The ratio of cyclic fatty acids to unsaturated fatty acids (CFA/UFA) appeared to be the most relevant parameter associated with membrane rigidification and cell resistance to freeze-drying and storage. This study increased our knowledge about the physiological mechanisms that explain the resistance of lactic acid bacteria (LAB) to freeze-drying and storage stresses and demonstrated the relevance of complementary methods of membrane characterization.

  9. 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.

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

    Science.gov (United States)

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

    2015-03-01

    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.

  11. 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

    are defined as probiotics. The positive clinical effects of probiotics, mainly belonging to the Bifidobacterium and Lactobacillus genera in treatments of irritable bowel syndrome, gut infections and lifestyle diseases are well documented. Compounds that selectively stimulate the beneficial effect......Bacterial communities (microbiota) of great diversity populate the large intestine of animals including humans and influence the physiology, biochemistry and immunology of the host. Microorganisms mainly bacteria that when administered in sufficient amounts promote a beneficial effect to the host...

  12. 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

    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...... XOS or glucose. The analyses show that 9 of the 10 genes that encode proteins predicted to play a role in XOS catabolism (i.e., XOS-degrading and -metabolizing enzymes, transport proteins, and a regulatory protein) were induced by XOS at the transcriptional level, and the proteins encoded by three...

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

    Directory of Open Access Journals (Sweden)

    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.

  14. 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

  15. 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

  16. Microencapsulation of probiotics in hydrogel particles: enhancing Lactococcus lactis subsp. cremoris LM0230 viability using calcium alginate beads.

    Science.gov (United States)

    Yeung, Timothy W; Arroyo-Maya, Izlia J; McClements, David J; Sela, David A

    2016-04-01

    Probiotics are beneficial microbes often added to food products to enhance the health and wellness of consumers. A major limitation to producing efficacious functional foods containing probiotic cells is their tendency to lose viability during storage and gastrointestinal transit. In this study, the impact of encapsulating probiotics within food-grade hydrogel particles to mitigate sensitivity to environmental stresses was examined. Confocal fluorescence microscopy confirmed that Lactococcus lactis were trapped within calcium alginate beads formed by dripping a probiotic-alginate mixture into a calcium solution. Encapsulation improved the viability of the probiotics during aerobic storage: after seven days, less than a two-log reduction was observed in encapsulated cells stored at room temperature, demonstrating that a high concentration of cells survived relative to non-encapsulated bacteria. These hydrogel beads may have applications for improving the stability and efficacy of probiotics in functional foods.

  17. Cloning and nucleotide sequence analysis of pepV, a carnosinase gene from Lactobacillus delbrueckii subsp. lactis DSM 7290, and partial characterization of the enzyme.

    Science.gov (United States)

    Vongerichten, K F; Klein, J R; Matern, H; Plapp, R

    1994-10-01

    Cell extracts of Lactobacillus delbrueckii subsp. lactis DSM 7290 were found to exhibit unique peptolytic ability against unusual beta-alanyl-dipeptides. In order to clone the gene encoding this activity, designated pepV, a gene library of strain DSM 7290 genomic DNA, prepared in the low-copy-number plasmid pLG339, was screened for heterologous expression in Escherichia coli. Recombinant clones harbouring pepV were identified by their ability to allow the utilization of carnosine (beta-alanyl-histidine) as a source of histidine by the E. coli mutant strain UK197 (pepD, hisG). Complementation was observed in a colony harbouring a recombinant plasmid (pKV101), carrying pepV. A 2.4 kb fragment containing pepV was subcloned and its nucleotide sequence revealed an open reading frame (ORF) of 1413 nucleotides, corresponding to a protein with predicted molecular mass of 51998 Da. A single transcription initiation site 71 bp upstream of the ATG translational start codon was identified by primer extension. No significant homology was detected between pepV or its deduced amino acid sequence with any entry in the databases. The only similarity was found in a region conserved in the ArgE/DapE/CPG2/YscS family of proteins. This observation, and protease inhibitor studies, indicated that pepV is of the metalloprotease type. A second ORF present in the sequenced fragment showed extensive homology to a variety of amino acid permeases from E. coli and Saccharomyces cerevisiae.

  18. Putrescine production by Lactococcus lactis subsp. cremoris CECT 8666 is reduced by NaCl via a decrease in bacterial growth and the repression of the genes involved in putrescine production.

    Science.gov (United States)

    Del Rio, Beatriz; Redruello, Begoña; Ladero, Victor; Fernandez, Maria; Martin, Maria Cruz; Alvarez, Miguel A

    2016-09-02

    The reduction of NaCl in food is a public health priority; high NaCl intakes have been associated with serious health problems. However, it is reported that reducing the NaCl content of cheeses may lead to an increase in the content of biogenic amines (BAs). The present work examines the effect of NaCl on the accumulation of putrescine (one of the BAs often detected at high concentration in cheese) in experimental Cabrales-like cheeses containing Lactococcus lactis subsp. cremoris CECT 8666, a dairy strain that catabolises agmatine to putrescine via the agmatine deiminase (AGDI) pathway. The genes responsible for this pathway are grouped in the AGDI cluster. This comprises a regulatory gene (aguR) (transcribed independently), followed by the catabolic genes that together form an operon (aguBDAC). Reducing the NaCl concentration of the cheese led to increased putrescine accumulation. In contrast, increasing the NaCl concentration of both pH-uncontrolled and pH-controlled (pH 6) cultures of L. lactis subsp. cremoris CECT 8666 significantly inhibited its growth and the production of putrescine. Such production appeared to be inhibited via a reduction in the transcription of the aguBDAC operon; no effect on the transcription of aguR was recorded. The present results suggest that low-sodium cheeses are at risk of accumulating higher concentrations of putrescine. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. 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

  20. 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

  1. 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.

  2. Reduced lysis upon growth of Lactococcus lactis on galactose is a consequence of decreased binding of the autolysin AcmA

    NARCIS (Netherlands)

    Steen, Anton; Buist, Girbe; Kramer, Naomi E.; Jalving, Ruud; Benus, Germaine F. J. D.; Venema, Gerard; Kuipers, Oscar P.; Kok, Jan

    When Lactococcus lactis subsp. lactis IL1403 or L. lactis subsp. cremoris MG1363 is grown in a medium with galactose as the carbon source, the culture lyses to a lesser extent in stationary phase than when the bacteria are grown in a medium containing glucose. Expression of AcmA, the major autolysin

  3. Growth interactions and antilisterial effects of the bacteriocinogenic Lactococcus lactis subsp. cremoris M104 and Enterococcus faecium KE82 strains in thermized milk in the presence or absence of a commercial starter culture.

    Science.gov (United States)

    Lianou, Alexandra; Kakouri, Athanasia; Pappa, Eleni C; Samelis, John

    2017-06-01

    Traditional Greek cheeses are often produced from thermized milk (TM) with the use of commercial starter cultures (CSCs), which may not inhibit growth of Listeria monocytogenes completely. Therefore, this study evaluated the behavior of an artificial L. monocytogenes contamination in commercially TM (63 °C; 30 s) inoculated with a CSC plus Lactococcus lactis subsp. lactis M104 and/or Enterococcus faecium KE82, two indigenous strains producing nisin A and enterocin A and B, respectively. Inoculation treatments included TM with the CSC only, and TM without the CSC but with strain M104 alone, or combined with strain KE82. All treatments were incubated at 37 °C for 6 h followed by 66 h at 18 °C. L. monocytogenes grew by 0.66-1.24 log cfu/ml at 37 °C, whereas its further growth at 18 °C was retarded, suppressed, or accompanied by different inactivation rates, depending on each TM treatment. Strain M104 caused the greatest inactivation, whereas the CSC per se was the least effective treatment. Strain KE82 assisted the CSC in controlling pathogen growth at 37 °C, whereas both reduced the nisin A-mediated antilisterial activity of strain M104. Overall, the most 'balanced' treatment against L. monocytogenes was CSC+M104+KE82. Hence, this starter/co-starter combination may be utilized in traditional Greek cheese technologies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. 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.

  5. Minimal requirements for exponential growth of Lactococcus lactis

    DEFF Research Database (Denmark)

    Jensen, Peter Ruhdal; Hammer, Karin

    1993-01-01

    A minimal growth medium containing glucose, acetate, vitamins, and eight amino acids allowed for growth of Lactococcus lactis subsp. lactis, with a specific growth rate in batch culture of mu = 0.3 h-1. With 19 amino acids added, the growth rate increased to mu = 0.7 h-1 and the exponential growth...

  6. Increase of nisin production by Lactococcus lactis in different media ...

    African Journals Online (AJOL)

    Nisin production related to the growth conditions of Lactococcus lactis subsp. lactis ATCC 11454, the effects of various media components and concomitant release of nisin into the media, were studied through transfers (five times). Nisin production was assayed by agar diffusion using Lactobacillus sake ATCC 15521 as the ...

  7. 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

  8. Complete genome sequence of Lactococcus lactis IO-1, a lactic acid bacterium that utilizes xylose and produces high levels of L-lactic acid.

    Science.gov (United States)

    Kato, Hiroaki; Shiwa, Yuh; Oshima, Kenshiro; Machii, Miki; Araya-Kojima, Tomoko; Zendo, Takeshi; Shimizu-Kadota, Mariko; Hattori, Masahira; Sonomoto, Kenji; Yoshikawa, Hirofumi

    2012-04-01

    We report the complete genome sequence of Lactococcus lactis IO-1 (= JCM7638). It is a nondairy lactic acid bacterium, produces nisin Z, ferments xylose, and produces predominantly L-lactic acid at high xylose concentrations. From ortholog analysis with other five L. lactis strains, IO-1 was identified as L. lactis subsp. lactis.

  9. 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

  10. 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.

  11. 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

  12. 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.

  13. Nisin Z Production by Lactococcus lactis subsp. cremoris WA2-67 of Aquatic Origin as a Defense Mechanism to Protect Rainbow Trout (Oncorhynchus mykiss, Walbaum) Against Lactococcus garvieae.

    Science.gov (United States)

    Araújo, Carlos; Muñoz-Atienza, Estefanía; Pérez-Sánchez, Tania; Poeta, Patrícia; Igrejas, Gilberto; Hernández, Pablo E; Herranz, Carmen; Ruiz-Zarzuela, Imanol; Cintas, Luis M

    2015-12-01

    Probiotics represent an alternative to chemotherapy and vaccination to control fish diseases, including lactococcosis caused by Lactococcus garvieae. The aims of this study were (i) to determine the in vitro probiotic properties of three bacteriocinogenic Lactococcus lactis subsp. cremoris of aquatic origin, (ii) to evaluate in vivo the ability of L. cremoris WA2-67 to protect rainbow trout (Oncorhynchus mykiss, Walbaum) against infection by L. garvieae, and (iii) to demonstrate the role of nisin Z (NisZ) production as an anti-infective mechanism. The three L. cremoris strains survived in freshwater at 18 °C for 7 days, withstood exposure to pH 3.0 and 10 % (v/v) rainbow trout bile, and showed different cell surface hydrophobicity (37.93-58.52 %). The wild-type NisZ-producer L. cremoris WA2-67 and its non-bacteriocinogenic mutant L. cremoris WA2-67 ∆nisZ were administered orally (10(6) CFU/g) to rainbow trout for 21 days and, subsequently, fish were challenged with L. garvieae CLG4 by the cohabitation method. The fish fed with the bacteriocinogenic strain L. cremoris WA2-67 reduced significantly (p trout against infection with the invasive pathogen L. garvieae and the relevance of NisZ production as an anti-infective mechanism. This is the first report demonstrating the effective in vivo role of LAB bacteriocin (NisZ) production as a mechanism to protect fish against bacterial infection. Our results suggest that the wild-type NisZ-producer strain L. cremoris WA2-67 could be used in fish farming to prevent lactococcosis in rainbow trout.

  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. 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...

  16. Cloning and analysis of the pepV dipeptidase gene of Lactococcus lactis MG1363

    NARCIS (Netherlands)

    Hellendoorn, Michiel A.; Franke-Fayard, Blandine M.D.; Mierau, Igor; Venema, Gerard; Kok, Jan

    The gene pepV, encoding a dipeptidase from Lactococcus lactis subsp. cremoris MG1363, was identified in a genomic library in pUC19 in a peptidase-deficient Escherichia coli strain and subsequently sequenced. PepV of L. lactis is enzymatically active in E. coli and hydrolyzes a broad range of

  17. Function and safety assessment of Lactococus lactis subsp. lactis ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-11-19

    Nov 19, 2008 ... Blood was obtained from the arteria cervicalis, the viscera were excised, weighed and tested for bacterial translocation aseptically. Blood placed in sterile tubes containing. EDTA as anticoagulant. Serum samples were isolated from the blood by centrifugation (4000 rpm for 30 min) and analyzed for total.

  18. Function and safety assessment of Lactococus lactis subsp. lactis ...

    African Journals Online (AJOL)

    the characterizations of the strain, such as acid-tolerance, bile-tolerance, antimicrobial activity, antibiotic sensitivity and safety were also examined. The serum total cholesterol, triglyceride and bile acid levels significantly decreased of mice given a high-cholesterol diet supplemented with yogurt fermented by Lactococus ...

  19. 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. 

  20. 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...... 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....

  1. Effects of gene disruptions in the nisin gene cluster of Lactococcus lactis on nisin production and producer immunity

    NARCIS (Netherlands)

    Ra, Runar; Beerthuyzen, Marke M.; Vos, Willem M. de; Saris, Per E.J.; Kuipers, Oscar P.

    1999-01-01

    The lantibiotic nisin is produced by several strains of Lactococcus lactis subsp. lactis. The chromosomally located gene cluster nisABTCIPRKFEG is required for biosynthesis, development of immunity, and regulation of gene expression. In-frame deletions in the nisB and nisT genes, and disruption of

  2. 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

  3. Glucose metabolism in Lactococcus lactis MG1363 under different aeration conditions: Requirement of acetate to sustain growth under microaerobic conditions

    DEFF Research Database (Denmark)

    Nordkvist, Mikkel; Jensen, N.B.S.; Villadsen, John

    2003-01-01

    Lactococcus lactis subsp. lactis MG1363 was grown in batch cultures on a defined medium with glucose as the energy source under different aeration conditions, namely, anaerobic conditions, aerobic conditions, and microaerobic conditions with a dissolved oxygen tension of 5% (when saturation with ...

  4. Infezione sperimentale di capre con un ceppo atipico di Mycoplasma mycoides subsp. capri isolato in Giordania: confronto tra differenti metodi diagnostici

    OpenAIRE

    Massimo Scacchia; Robin A.J. Nicholas; Chiara De Caro; Flavio Sacchini; Gabriella Di Francesco; Andrea Di Provvido; Anna Rita D’Angelo

    2010-01-01

    Sono state infettate sperimentalmente 10 capre con un micoplasma identificato con metodi biomolecolari come Mycoplasma mycoides subsp. capri, ceppo Irbid, isolato da capre in un focolaio di agalassia contagiosa nel nord della Giordania e definito atipico per la sua peculiarità sierologica. Due gruppi di animali infettati rispettivamente per via endotracheale e aerosol sono stati posti in contatto con un terzo gruppo di capre. A sei settimane dall’infezione alcuni animali, sia infettati sia po...

  5. The pyrH gene of Lactococcus lactis subsp. cremoris encoding UMP kinase is transcribed as part of an operon including the frr1 gene encoding ribosomal recycling factor

    DEFF Research Database (Denmark)

    Wadskov-Hansen, Steen Lüders; Martinussen, Jan; Hammer, Karin

    2000-01-01

    establishing the ability of the encoded protein to synthesize UDP. The pyrH gene in L. lactis is flanked downstream by frr1 encoding ribosomal recycling factor 1 and upstream by an open reading frame, orfA, of unknown function. The three genes were shown to constitute an operon transcribed in the direction orf......A-pyrH-frr1 from a promoter immediately in front of orfA. This operon belongs to an evolutionary highly conserved gene cluster, since the organization of pyrH on the chromosomal level in L. lactis shows a high resemblance to that found in Bacillus subtilis as well as in Escherichia coli and several other...

  6. 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.

  7. Thymus vulgaris subsp. mansanetianus subsp. nov. (Lamiaceae)

    OpenAIRE

    Ferrer-Gallego, Pedro Pablo; Navarro Peris, Albert Josep; Laguna Lumbreras, Emilio; Mateo Sanz, Gonzalo

    2013-01-01

    RESUMEN: Se describe una nueva subespecie de Thymus vulgaris L. (Lamiaceae); Th. vulgaris subsp. mansanetianus subsp. nov., caracterizada por presentar un hábito postrado, tallos estoloníferos, decumbentes y radicantes, hojas muy estrechas y una floración otoñal. ABSTRACT: Thymus vulgaris subsp. mansanetianus subsp. nov. (Lamiaceae). A new subspecies of Thymus vulgaris L. (Lamiaceae); Th. vulgaris subsp. mansanetianus subsp. nov. is described. This new subspecies is characterized by its prost...

  8. 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...

  9. 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.

  10. 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

  11. Effects of structural modifications on some physical characteristics of exopolysaccharides from Lactococcus lactis

    NARCIS (Netherlands)

    Tuinier, R.; Casteren, van W.H.M.; Looijesteijn, P.J.; Schols, H.A.; Voragen, A.G.J.; Zoon, P.

    2001-01-01

    The relationship between the primary structure and the chain stiffness of exopolysaccharides (EPSs) and modified EPSs produced by two strains of Lactococcus lactis subsp. cremoris was investigated. The molar mass and radius of gyration of these exopolysaccharides were analyzed by multiangle static

  12. Behavior and viability of spontaneous oxidative stress-resistant Lactococcus lactis mutants in experimental fermented milk processing

    OpenAIRE

    OLIVEIRA, M. N.; ALMEIDA, K. E.; DAMIN, M. R.; ROCHAT, T.; GRATADOUX, J. -J.; MIYOSHI, A.; LANGELLA, P.; AZEVEDO, V.

    2009-01-01

    Previously, we isolated two strains of spontaneous oxidative (SpOx2 and SpOx3) stress mutants of Lactococcus lactis subsp cremoris. Herein, we compared these mutants to a parental wild- type strain (J60011) and a commercial starter in experimental fermented milk production. Total solid contents of milk and fermentation temperature both affected the acidification profile of the spontaneous oxidative stress- resistant L. lactis mutants during fermented milk production. Fermentation times to pH ...

  13. A β1-6/β1-3 galactosidase from B ifidobacterium animalis subsp. lactis Bl-04 gives insight into sub-specificities of β-galactoside catabolism within B ifidobacterium

    DEFF Research Database (Denmark)

    Viborg, Alexander Holm; Fredslund, Folmer; Katayama, Takane

    2014-01-01

    The Bifidobacterium genus harbours several health promoting members of the gut microbiota. Bifidobacteria display metabolic specialization by preferentially utilizing dietary or host-derived β-galactosides. This study investigates the biochemistry and structure of a glycoside hydrolase family 42 ...

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. Activation and Transfer of the Chromosomal Phage Resistance Mechanism AbiV in Lactococcus lactis

    DEFF Research Database (Denmark)

    Haaber, J.; Moineau, S.; Hammer, Karin

    2009-01-01

    AbiV is a chromosomally encoded phage resistance mechanism that is silent in the wild-type phage-sensitive strain Lactococcus lactis subsp. cremoris MG1363. Spontaneous phage-resistant mutants of L. lactis MG1363 were analyzed by reverse transcriptase PCR and shown to express AbiV. This expression...... was related to a reorganization in the upstream region of abiV. Transfer of abiV between two lactococcal strains, most likely by conjugation, was also demonstrated. To our knowledge, this is the first report of natural transfer of a chromosomally encoded phage resistance mechanism....

  1. 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....

  2. 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.

  3. Characterization, expression, and mutation of the Lactococcus lactis galPMKTE genes, involved in galactose utilization via the Leloir pathway

    NARCIS (Netherlands)

    Groossiord, B.P.; Luesink, E.J.; Vaughan, E.E.; Arnaud, A.; Vos, de W.M.

    2003-01-01

    A cluster containing five similarly oriented genes involved in the metabolism of galactose via the Leloir pathway in Lactococcus lactis subsp. cremoris MG1363 was cloned and characterized. The order of the genes is galPMKTE, and these genes encode a galactose permease (GalP), an aldose I-epimerase

  4. The riboflavin transporter RibU in Lactococcus lactis : Molecular characterization of gene expression and the transport mechanism

    NARCIS (Netherlands)

    Burgess, CM; Slotboom, DJ; Geertsma, ER; Duurkens, Hinderika; Poolman, B; van Sinderen, D

    This study describes the characterization of the riboflavin transport protein RibU in the lactic acid bacterium Lactococcus lactis subsp. cremoris NZ9000. RibU is predicted to contain five membrane-spanning segments and is a member of a novel transport protein family, not described in the Transport

  5. Lytic Infection of Lactococcus lactis by Bacteriophages Tuc2009 and c2 Triggers Alternative Transcriptional Host Responses

    NARCIS (Netherlands)

    Ainsworth, S.; Zomer, A.L.; Mahony, J.; Sinderen, D. van

    2013-01-01

    Here we present an entire temporal transcriptional profile of Lactococcus lactis subsp. cremoris UC509.9 undergoing lytic infection with two distinct bacteriophages, Tuc2009 and c2. Furthermore, corresponding high-resolution whole-phage genome tiling arrays of both bacteriophages were performed

  6. Infezione sperimentale di capre con un ceppo atipico di Mycoplasma mycoides subsp. capri isolato in Giordania: confronto tra differenti metodi diagnostici

    Directory of Open Access Journals (Sweden)

    Massimo Scacchia

    2010-06-01

    Full Text Available Sono state infettate sperimentalmente 10 capre con un micoplasma identificato con metodi biomolecolari come Mycoplasma mycoides subsp. capri, ceppo Irbid, isolato da capre in un focolaio di agalassia contagiosa nel nord della Giordania e definito atipico per la sua peculiarità sierologica. Due gruppi di animali infettati rispettivamente per via endotracheale e aerosol sono stati posti in contatto con un terzo gruppo di capre. A sei settimane dall’infezione alcuni animali, sia infettati sia posti in contatto, hanno manifestato febbre, scolo nasale, seguiti da grave sintomatologia respiratoria e poliartrite. Dagli animali deceduti o sacrificati, perché giunti al termine della sperimentazione, sono stati effettuati prelievi di organi. Dopo una descrizione dei quadri clinici ed anatomo-istopatologici, sono stati messi a confronto gli esiti degli isolamenti microbiologici e delle prove immunoisto-chimiche effettuate sugli organi prelevati.

  7. Butanol is cytotoxic to Lactococcus lactis while ethanol and hexanol are cytostatic

    DEFF Research Database (Denmark)

    Hviid, Anne-Mette Meisner; Jensen, Peter Ruhdal; Kilstrup, Mogens

    2017-01-01

    attention. In the present study the physiological alcohol stress response of Lactococcus lactis subsp. cremoris MG1363 towards the primary, even-chain alcohols; ethanol, butanol, and hexanol was characterized. The alcohol tolerance of L. lactis was found comparable to those reported for highly alcohol......Lactic acid bacteria currently used extensively by the dairy industry have a superior tolerance towards small chain alcohols, which makes them interesting targets for use in future bio-refineries. The mechanism underlying the alcohol tolerance of lactic acid bacteria has so far received little...... resistant lactic acid bacteria. Combined results from alcohol survival rate, live/dead staining, and a novel usage of the beta-galactosidase assay, revealed that while high concentrations of ethanol and hexanol were cytostatic to L. lactis, high concentrations of butanol were cytotoxic, causing irreparable...

  8. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    Cvrtila, Jelena; Topić, Ivana; Delaš, Frane; Markov, Ksenija

    2014-01-01

    Summary 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. PMID:27904322

  11. Molecular Cloning and Nucleotide Sequence of the Gene Encoding the Major Peptidoglycan Hydrolase of Lactococcus lactis, a Muramidase Needed for Cell Separation

    NARCIS (Netherlands)

    Buist, Girbe; Kok, Jan; Leenhouts, Kees J.; Dabrowska, Magdalena; Venema, Gerhardus; Haandrikman, Alfred J.

    A gene of Lactococcus lactis subsp, cremoris MG1363 encoding a peptidoglycan hydrolase was identified in a genomic library of the strain in pUC19 by screening Escherichia coli transformants for cell wall lysis activity on a medium containing autoclaved, lyophilized Micrococcus lysodeikticus cells,

  12. 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.

  13. 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....

  14. Improved viability of bifidobacteria in fermented milk by cocultivation with Lactococcus lactis subspecies lactis.

    Science.gov (United States)

    Odamaki, T; Xiao, J Z; Yonezawa, S; Yaeshima, T; Iwatsuki, K

    2011-03-01

    The poor survival of probiotic bacteria in commercial yogurts may limit their potential to exert health benefits in humans. The objective was to improve the survival of bifidobacteria in fermented milk. Cocultivation with some strains of Lactococcus lactis ssp. lactis improved the survival of bifidobacteria in fermented milk during refrigerated storage. Studies on one strain, Lc. lactis ssp. lactis MCC866, showed that the concentrations of dissolved oxygen were kept lower in the cocultivated fermented milk during storage compared with monocultured Bifidobacterium longum BB536 or samples cocultured with another noneffective Lc. lactis ssp. lactis strain. Degradation of genomic DNA was suppressed in the cocultivating system with Lc. lactis ssp. lactis MCC866. Several genes that participated in protection from active oxygen species (e.g., genes coding for alkyl hydroperoxide reductase and Fe(2+) transport system) were expressed at higher levels during refrigerated storage in Lc. lactis ssp. lactis MCC 866 compared with another noneffective Lc. lactis ssp. lactis strain. Concentration of free iron ion was also lower in supernatants of fermented milk cocultivated with B. longum BB536 and Lc. lactis ssp. lactis MCC866. These results suggest that Lc. lactis ssp. lactis MCC 866 is potentially superior in reducing oxygen damage and consequently improves the survival of bifidobacteria in the cocultivating system. This cocultivation system is of industrial interest for producing fermented milk containing viable bifidobacteria with long shelf life. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  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. 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

  17. Effect of Bifidobacterium animalis B/12 administration in healthy dogs.

    Science.gov (United States)

    Strompfová, Viola; Pogány Simonová, Monika; Gancarčíková, Soňa; Mudroňová, Dagmar; Farbáková, Jana; Mad'ari, Aladár; Lauková, Andrea

    2014-08-01

    Bifidobacterium species constitute the most frequently used health-enhancing bacteria in functional foods or probiotic products, and most of their health benefits have been demonstrated in human or mice studies. However, knowledge of the effects of these bacteria in the canine organism is very limited. In this study, the canine-derived strain Bifidobacterium animalis B/12 (10(9) CFU) was tested for its effects on faecal microbiota, faecal characteristics, faecal organic acid concentrations, blood biochemistry, haematological and immunological parameters in healthy dogs (C-control, BA-B. animalis B/12 group, 10 dogs in each). The experiment lasted for 49 days with a 14-day treatment period (sample collection at days 0, 7, 14, 21, 28, and 49). A significantly higher population of lactic acid bacteria was detected (day 7) while the counts of coliform bacteria were lower in faeces of the BA group (days 14, 21, 28, 49) compared to control group C. Faecal concentrations of acetic (day 7, 21, 28, 49), acetoacetic (7-49) and valeric acid (14) were higher in contrast to formic acid (day 7-21), which was decreased after the treatment. In blood serum, significantly lower concentrations of triglyceride (day 14) and albumin (day 14, 28, 49) and significantly higher levels of alanine aminotransferase (day 14) and alkaline phosphatase (day 14, 28) were observed in the BA dogs. The phagocytic activity of leukocytes (especially of neutrophils) was higher in dogs after 14-day consumption of B/12 strain (day 14). The results show that many of these effects could also still be recorded several weeks after the treatment period. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. 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.

  19. Genotypic and Phenotypic Analysis of Dairy Lactococcus lactis Biodiversity in Milk: Volatile Organic Compounds as Discriminating Markers

    Science.gov (United States)

    Dhaisne, Amandine; Guellerin, Maeva; Laroute, Valérie; Laguerre, Sandrine; Le Bourgeois, Pascal; Loubiere, Pascal

    2013-01-01

    The diversity of nine dairy strains of Lactococcus lactis subsp. lactis in fermented milk was investigated by both genotypic and phenotypic analyses. Pulsed-field gel electrophoresis and multilocus sequence typing were used to establish an integrated genotypic classification. This classification was coherent with discrimination of the L. lactis subsp. lactis bv. diacetylactis lineage and reflected clonal complex phylogeny and the uniqueness of the genomes of these strains. To assess phenotypic diversity, 82 variables were selected as important dairy features; they included physiological descriptors and the production of metabolites and volatile organic compounds (VOCs). Principal-component analysis (PCA) demonstrated the phenotypic uniqueness of each of these genetically closely related strains, allowing strain discrimination. A method of variable selection was developed to reduce the time-consuming experimentation. We therefore identified 20 variables, all associated with VOCs, as phenotypic markers allowing discrimination between strain groups. These markers are representative of the three metabolic pathways involved in flavor: lipolysis, proteolysis, and glycolysis. Despite great phenotypic diversity, the strains could be divided into four robust phenotypic clusters based on their metabolic orientations. Inclusion of genotypic diversity in addition to phenotypic characters in the classification led to five clusters rather than four being defined. However, genotypic characters make a smaller contribution than phenotypic variables (no genetic distances selected among the most contributory variables). This work proposes an original method for the phenotypic differentiation of closely related strains in milk and may be the first step toward a predictive classification for the manufacture of starters. PMID:23709512

  20. Production of Pediocin PA-1 by Lactococcus lactis Using the Lactococcin A Secretory Apparatus

    Science.gov (United States)

    Horn, Nikki; Martínez, María I.; Martínez, José M.; Hernández, Pablo E.; Gasson, Michael J.; Rodríguez, Juan M.; Dodd, Helen M.

    1998-01-01

    The class II bacteriocins pediocin PA-1, from Pediococcus acidilactici, and lactococcin A, from Lactococcus lactis subsp. lactis bv. diacetylactis WM4 have a number of features in common. They are produced as precursor peptides containing similar amino-terminal leader sequences with a conserved processing site (Gly-Gly at positions −1 and −2). Translocation of both bacteriocins occurs via a dedicated secretory system. Because of the strong antilisterial activity of pediocin PA-1, its production by lactic acid bacteria strains adapted to dairy environments would considerably extend its application in the dairy industry. In this study, the lactococcin A secretory system was adapted for the expression and secretion of pediocin PA-1. A vector containing an in-frame fusion of sequences encoding the lcnA promoter, the lactococcin A leader, and the mature pediocin PA-1, was introduced into L. lactis IL1403. This strain is resistant to pediocin PA-1 and encodes a lactococcin translocation apparatus. The resulting L. lactis strains secreted a bacteriocin with an antimicrobial activity of approximately 25% of that displayed by the parental pediocin-producing P. acidilactici 347. A noncompetitive indirect enzyme-linked immunosorbent assay with pediocin PA-1-specific antibodies and amino-terminal amino acid sequencing confirmed that pediocin PA-1 was being produced by the heterologous host. PMID:9501421

  1. 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

  2. Putrescine production via the agmatine deiminase pathway increases the growth of Lactococcus lactis and causes the alkalinization of the culture medium.

    Science.gov (United States)

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

    2015-01-01

    Lactococcus lactis is the most important starter culture organism used in the dairy industry. Although L. lactis species have been awarded Qualified Presumption of Safety status by the European Food Safety Authority, and Generally Regarded as Safe status by the US Food and Drug Administration, some strains can produce the biogenic amine putrescine. One such strain is L. lactis subsp. cremoris CECT 8666 (formerly L. lactis subsp. cremoris GE2-14), which was isolated from Genestoso cheese. This strain catabolizes agmatine to putrescine via the agmatine deiminase (AGDI) pathway, which involves the production of ATP and two ammonium ions. The present work shows that the availability of agmatine and its metabolization to putrescine allows for greater bacterial growth (in a biphasic pattern) and causes the alkalinization of the culture medium in a dose-dependent manner. The construction of a mutant lacking the AGDI cluster (L. lactis CECT 8666 Δagdi) confirmed the latter's direct role in putrescine production, growth, and medium alkalinization. Alkalinization did not affect the putrescine production pattern and was not essential for increased bacterial growth.

  3. 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......, although maximum induction was observed earlier for orf1 and grpE. Novel transcript sizes were detected in heat-shocked cells. The induction kinetics observed for ftsH suggested a different regulation for this gene. Experimental evidence for a prenounced transcriptional regulation being involved...... 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....

  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. 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.

  6. Combination of Metabolomic and Proteomic Analysis Revealed Different Features among Lactobacillus delbrueckii Subspecies bulgaricus and lactis Strains While In Vivo Testing in the Model Organism Caenorhabditis elegans Highlighted Probiotic Properties

    Directory of Open Access Journals (Sweden)

    Elena Zanni

    2017-06-01

    Full Text Available Lactobacillus delbrueckii represents a technologically relevant member of lactic acid bacteria, since the two subspecies bulgaricus and lactis are widely associated with fermented dairy products. In the present work, we report the characterization of two commercial strains belonging to L. delbrueckii subspecies bulgaricus, lactis and a novel strain previously isolated from a traditional fermented fresh cheese. A phenomic approach was performed by combining metabolomic and proteomic analysis of the three strains, which were subsequently supplemented as food source to the model organism Caenorhabditis elegans, with the final aim to evaluate their possible probiotic effects. Restriction analysis of 16S ribosomal DNA revealed that the novel foodborne strain belonged to L. delbrueckii subspecies lactis. Proteomic and metabolomic approaches showed differences in folate, aminoacid and sugar metabolic pathways among the three strains. Moreover, evaluation of C. elegans lifespan, larval development, brood size, and bacterial colonization capacity demonstrated that L. delbrueckii subsp. bulgaricus diet exerted beneficial effects on nematodes. On the other hand, both L. delbrueckii subsp. lactis strains affected lifespan and larval development. We have characterized three strains belonging to L. delbrueckii subspecies bulgaricus and lactis highlighting their divergent origin. In particular, the two closely related isolates L. delbrueckii subspecies lactis display different galactose metabolic capabilities. Moreover, the L. delbrueckii subspecies bulgaricus strain demonstrated potential probiotic features. Combination of omic platforms coupled with in vivo screening in the simple model organism C. elegans is a powerful tool to characterize industrially relevant bacterial isolates.

  7. Combination of Metabolomic and Proteomic Analysis Revealed Different Features among Lactobacillus delbrueckii Subspecies bulgaricus and lactis Strains While In Vivo Testing in the Model Organism Caenorhabditis elegans Highlighted Probiotic Properties.

    Science.gov (United States)

    Zanni, Elena; Schifano, Emily; Motta, Sara; Sciubba, Fabio; Palleschi, Claudio; Mauri, Pierluigi; Perozzi, Giuditta; Uccelletti, Daniela; Devirgiliis, Chiara; Miccheli, Alfredo

    2017-01-01

    Lactobacillus delbrueckii represents a technologically relevant member of lactic acid bacteria, since the two subspecies bulgaricus and lactis are widely associated with fermented dairy products. In the present work, we report the characterization of two commercial strains belonging to L. delbrueckii subspecies bulgaricus , lactis and a novel strain previously isolated from a traditional fermented fresh cheese. A phenomic approach was performed by combining metabolomic and proteomic analysis of the three strains, which were subsequently supplemented as food source to the model organism Caenorhabditis elegans , with the final aim to evaluate their possible probiotic effects. Restriction analysis of 16S ribosomal DNA revealed that the novel foodborne strain belonged to L. delbrueckii subspecies lactis . Proteomic and metabolomic approaches showed differences in folate, aminoacid and sugar metabolic pathways among the three strains. Moreover, evaluation of C. elegans lifespan, larval development, brood size, and bacterial colonization capacity demonstrated that L. delbrueckii subsp. bulgaricus diet exerted beneficial effects on nematodes. On the other hand, both L. delbrueckii subsp. lactis strains affected lifespan and larval development. We have characterized three strains belonging to L. delbrueckii subspecies bulgaricus and lactis highlighting their divergent origin. In particular, the two closely related isolates L. delbrueckii subspecies lactis display different galactose metabolic capabilities. Moreover, the L. delbrueckii subspecies bulgaricus strain demonstrated potential probiotic features. Combination of omic platforms coupled with in vivo screening in the simple model organism C. elegans is a powerful tool to characterize industrially relevant bacterial isolates.

  8. Ernesto e gli animali: note sul romanzo di Umberto Saba

    Directory of Open Access Journals (Sweden)

    Maurizio Esposito La Rossa

    2016-05-01

    Full Text Available «Una rivoluzione […] su ali di colomba»: così Saba definisce il suo primo e ultimo romanzo, Ernesto. In questo studio mi sono proposto di interrogare il senso di questa definizione di derivazione nietzschiana e quindi il carattere rivoluzionario che l’autore conferisce – o vuole conferire – all’opera. A tal fine, l’analisi si centra sul protagonista, portatore di questa rivoluzione, e in particolare sui modelli che hanno ispirato Saba per la creazione del suo carattere “primitivo”: gli animali. Questi dispositivi simbolici, presenti in maniera implicita nel testo e in modo sparso in tutta l’opera di Saba, sono qui rivalorizzati e messi in luce in quanto chiave di interpretazione del romanzo e quindi della poetica di Saba più in generale.«A revolution [...] on the wings of a dove»: thus Saba defines his first and last novel, Ernesto. This study aims at questioning the meaning of this Nietzschean definition and at inquiring the revolutionary character the author gives - or wants to give - to his work. The analysis focuses on the protagonist, who is the bearer of this revolution, and particular attention is given to the elements that inspired Saba for the creation of his “primitive” feature: animals. Animals as symbolic devices, implicitly present in the novel and scattered throughout Saba's work, are here highlighted as key factors to the interpretation of Ernesto and, possibly, of Saba's poetics in general.

  9. Modification de la composition lipidique membranaire chez les bactéries lactiques en conditions de stress : étude du rôle physiologique des Acides Gras Cycliques chez deux modèles : oenococcus oeni ATCC-BAA1163 et Lactococcus lactis MG1363

    OpenAIRE

    To, Thi Mai Huong

    2010-01-01

    The results obtained in this work have shown that in both lactic acid bacteria models, L. lactis subsp. cremoris and O. oeni, transcription of the cfa gene, encoding the Cfa synthase is stimulated when cells enter stationary phase of growth or when the cells are grown under stress conditions (acidic or presence of ethanol in the medium). The role of the CFAs has been apprehended by the comparative physiological analysis of the parental strain L. lactis subsp. cremoris and a Δcfa mutant genera...

  10. 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.

  11. The Lactococcus lactis Thioredoxin System

    DEFF Research Database (Denmark)

    Efler, Petr

    -dependent thioredoxin reductase (NTR) in order to complete its catalytic cycle. Glutathione-dependent glutaredoxin complements Trx in many organisms. This thesis focuses on disulfide reduction pathways in Lactococcus lactis, an important industrial microorganism used traditionally for cheese and buttermilk production....... L. lactis lacks glutathione and glutaredoxin, but it a contains Trx system consisting of an NTR (LlTrxB), a classical Trx (LlTrxA) containing the conserved WCGPC active site motif, a Trx-like protein (LlTrxD) containing a WCGDC active site motif and a redoxin (LlNrdH) providing electrons to class Ib...... ribonucleotide reductase (NrdEF). Physiological functions of LlTrxA and LlTrxD were studied using ΔtrxA, ΔtrxD and ΔtrxAΔtrxD mutant strains of L. lactis ssp. cremoris MG1363 exposed to various stress conditions and comparing them to the wild type (wt) strain. These experiments revealed that the ΔtrxA genotype...

  12. Book review. Procedure cliniche e terapeutiche negli animali esotici. Marta Avanzi

    OpenAIRE

    Manuel Graziani

    2014-01-01

    Negli ultimi anni è in costante aumento il numero degli animali da compagnia, con la diretta conseguenza che negli ambulatori veterinari arrivano sempre più pet diversi dal cane e dal gatto. Per dare loro cure di qualità non è sufficiente conoscere soltanto la fisiologia e la patologia ma c'è bisogno di saper maneggiare correttamente questi animali non convenzionali, oltre che conoscere le procedure per arrivare a una diagnosi e quindi ad una terapia appropriata. Procedure cliniche e terapeut...

  13. 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

  14. 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...

  15. Lactococcus lactis Diversity in Undefined Mixed Dairy Starter Cultures as Revealed by Comparative Genome Analyses and Targeted Amplicon Sequencing of epsD.

    Science.gov (United States)

    Frantzen, Cyril A; Kleppen, Hans Petter; Holo, Helge

    2018-02-01

    Undefined mesophilic mixed (DL) starter cultures are used in the production of continental cheeses and contain unknown strain mixtures of Lactococcus lactis and leuconostocs. The choice of starter culture affects the taste, aroma, and quality of the final product. To gain insight into the diversity of Lactococcus lactis strains in starter cultures, we whole-genome sequenced 95 isolates from three different starter cultures. Pan-genomic analyses, which included 30 publically available complete genomes, grouped the strains into 21 L. lactis subsp . lactis and 28 L. lactis subsp. cremoris lineages. Only one of the 95 isolates grouped with previously sequenced strains, and the three starter cultures showed no overlap in lineage distributions. The culture diversity was assessed by targeted amplicon sequencing using purR , a core gene, and epsD , present in 93 of the 95 starter culture isolates but absent in most of the reference strains. This enabled an unprecedented discrimination of starter culture Lactococcus lactis and revealed substantial differences between the three starter cultures and compositional shifts during the cultivation of cultures in milk. IMPORTANCE In contemporary cheese production, standardized frozen seed stock starter cultures are used to ensure production stability, reproducibility, and quality control of the product. The dairy industry experiences significant disruptions of cheese production due to phage attacks, and one commonly used countermeasure to phage attack is to employ a starter rotation strategy, in which two or more starters with minimal overlap in phage sensitivity are used alternately. A culture-independent analysis of the lactococcal diversity in complex undefined starter cultures revealed large differences between the three starter cultures and temporal shifts in lactococcal composition during the production of bulk starters. A better understanding of the lactococcal diversity in starter cultures will enable the development of

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

    Directory of Open Access Journals (Sweden)

    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.

  17. 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 plantarum WCFS1, during set-yoghurt

  18. 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

  19. 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,

  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. [Streptococcus equi subsp. Zooepidemicus endocarditis].

    Science.gov (United States)

    Villamil, Iago; Serrano, Marta; Prieto, Elisabeth

    2015-04-01

    Zoonotic infections with S. equi subsp. zooepidemicus have been reported occasionally in individuáis with exposure to farm animals, especially horses. They exceptionally present as a human pathogen. We present a S. equi subsp. zooepidemicus well documented endocarditis after a horse's female genital tract contact, and excellent surveillance with exclusive antibiotic management.

  2. Early adaptation to oxygen is key to the industrially important traits of Lactococcus lactis ssp. cremoris during milk fermentation.

    Science.gov (United States)

    Cretenet, Marina; Le Gall, Gwenaëlle; Wegmann, Udo; Even, Sergine; Shearman, Claire; Stentz, Régis; Jeanson, Sophie

    2014-12-03

    Lactococcus lactis is the most used species in the dairy industry. Its ability to adapt to technological stresses, such as oxidative stress encountered during stirring in the first stages of the cheese-making process, is a key factor to measure its technological performance. This study aimed to understand the response to oxidative stress of Lactococcus lactis subsp. cremoris MG1363 at the transcriptional and metabolic levels in relation to acidification kinetics and growth conditions, especially at an early stage of growth. For those purposes, conditions of hyper-oxygenation were initially fixed for the fermentation. Kinetics of growth and acidification were not affected by the presence of oxygen, indicating a high resistance to oxygen of the L. lactis MG1363 strain. Its resistance was explained by an efficient consumption of oxygen within the first 4 hours of culture, leading to a drop of the redox potential. The efficient consumption of oxygen by the L. lactis MG1363 strain was supported by a coherent and early adaptation to oxygen after 1 hour of culture at both gene expression and metabolic levels. In oxygen metabolism, the over-expression of all the genes of the nrd (ribonucleotide reductases) operon or fhu (ferrichrome ABC transports) genes was particularly significant. In carbon metabolism, the presence of oxygen led to an early shift at the gene level in the pyruvate pathway towards the acetate/2,3-butanediol pathway confirmed by the kinetics of metabolite production. Finally, the MG1363 strain was no longer able to consume oxygen in the stationary growth phase, leading to a drastic loss of culturability as a consequence of cumulative stresses and the absence of gene adaptation at this stage. Combining metabolic and transcriptomic profiling, together with oxygen consumption kinetics, yielded new insights into the whole genome adaptation of L. lactis to initial oxidative stress. An early and transitional adaptation to oxidative stress was revealed for L

  3. Physical and physicochemical stability evaluation of cosmetic formulations containing soybean extract fermented by Bifidobacterium animalis

    OpenAIRE

    Rafael Pinto Vieira; Alessandra Ribeiro Fernandes; Telma Mary Kaneko; Vladi Olga Consiglieri; Claudinéia Aparecida Sales de Oliveira Pinto; Claudia Silva Cortez Pereira; André Rolim Baby; Maria Valéria Robles Velasco

    2009-01-01

    Peel off facial masks, based on polyvinyl alcohol (PVA), are formulations that, after application and drying, form an occlusive film over the face. After removing, they provide cleanness, tensor and moisturizing effects, removing dead cells, residues and other materials deposited on the stratum corneous. The soybean extract fermented by Bifidobacterium animalis has sugars, amino acids, peptides, proteins and free isoflavonoids in high concentrations, when compared to the unfermented extract, ...

  4. Book review. Procedure cliniche e terapeutiche negli animali esotici. Marta Avanzi

    Directory of Open Access Journals (Sweden)

    Manuel Graziani

    2014-12-01

    Full Text Available Negli ultimi anni è in costante aumento il numero degli animali da compagnia, con la diretta conseguenza che negli ambulatori veterinari arrivano sempre più pet diversi dal cane e dal gatto. Per dare loro cure di qualità non è sufficiente conoscere soltanto la fisiologia e la patologia ma c'è bisogno di saper maneggiare correttamente questi animali non convenzionali, oltre che conoscere le procedure per arrivare a una diagnosi e quindi ad una terapia appropriata. Procedure cliniche e terapeutiche negli animali esotici di Marta Avanzi risponde al bisogno di conoscenza in un settore in cui la formazione accademica è ancora scarsa, a fronte di un aumento della richiesta di cure da parte dei proprietari. Come scrive l'autrice nella prefazione: "Non sempre il professionista ha la possibilità di seguire un periodo di tirocinio pratico presso colleghi più esperti e spesso è la mancanza di esperienza che scoraggia il neofita ad ampliare il range di specie a cui dedicarsi. Il libro nasce proprio dall'esigenza di colmare questa lacuna, rispondendo al bisogno crescente di formazione nel campo della cura e del trattamento degli animali esotici da compagnia". Il manuale della dott.ssa Avanzi illustra con chiarezza le procedure diagnostiche, anestesiologiche, terapeutiche indispensabili per la pratica clinica. Per questo è rivolto principalmente ai medici veterinari che si occupano degli animali esotici da compagnia quali furetti, conigli, roditori, uccelli e rettili, di cui vengono illustrate le tecniche fondamentali per maneggiarli e contenerli con competenza e sicurezza. Il volume, pubblicato nel grande formato 19,5x26,5 cm, contiene più di mille fotografie a colori, comprese quelle delle attrezzature specifiche per i vari casi. Un'iconografia ricchissima che ha la funzione di descrivere passo dopo passo le manovre e le procedure per trattare questi particolari pazienti. I capitoli sono 14 e descrivono circa 150 procedure, dalla dermatologia all

  5. 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.

  6. 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

  7. Taxonomic relatedness between Pectobacterium carotovorum subsp. carotovorum, Pectobacterium carotovorum subsp. odoriferum and Pectobacterium carotovorum subsp. brasiliense subsp. nov.

    Science.gov (United States)

    Nabhan, S; De Boer, S H; Maiss, E; Wydra, K

    2012-10-01

    Pectobacterium carotovorum is a heterogeneous species consisting of two named subspecies, P. carotovorum subsp. carotovorum and P. carotovorum subsp. odoriferum. A third subspecies, P. carotovorum subsp. brasiliense, was previously proposed. The study aimed to confirm the subspecies status and validate the proposed name of P. carotovorum subsp. brasiliense using a novel and standard microbial taxonomy. DNA-DNA hybridization confirmed that P. carotovorum subsp. brasiliense is a different species from P. wasabiae, P. betavasculorum and P. atrosepticum, with 28, 35 and 55% similarity values, respectively, but is a member of the P. carotovorum species with 73-77% similarity values. Sequencing the entire 16S rRNA gene of two polymorphic copies from strains of each of the P. carotovorum subspecies demonstrated that the average 16S rRNA gene sequence diversity between P. carotovorum subsp. brasiliense and P. carotovorum subsp. carotovorum was lower than the maximum genetic distances between two sequence types obtained from the same strain. Multilocus sequence analysis based on eight housekeeping genes (mtlD, acnA, icdA, mdh, pgi, gabA, proA and rpoS) differentiated the subspecies and delineated two P. carotovorum subsp. brasiliense clades. Pectobacterium carotovorum subsp. brasiliense clade I was comprised of strains isolated from Brazil and Peru, while clade II included strains from Asia, North America and Europe. Strains in clade I but not clade II were phenotypically consistent with the original description of P. carotovorum subsp. brasiliense in that they produced reducing substances from sucrose and acid from α-methyl glucoside. The type strain for P. carotovorum subsp. brasiliense 212(T) (= LMG2137(T) = IBSBF1692(T) = CFBP6617(T) ) was previously designated. The GC mol content of the type strain is 51·7%. the study introduces a full description for the strains belonging to the two different clades assigned to P. carotovorum subsp. brasiliense.

  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. 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

  10. Metabolic behavior of Lactococcus lactis MG1363 in microaerobic continuous cultivation at a low dilution rate

    DEFF Research Database (Denmark)

    Jensen, Niels B.S.; Melchiorsen, Claus Rix; Jochumsen, Kirsten Væver

    2001-01-01

    Minute amounts of oxygen were supplied to a continuous cultivation of Lactococcus lactis subsp. cremoris MG1363 grown on a defined glucose-limited medium at a dilution rate of 0.1 h(-1). More than 80% of the carbon supplied with glucose ended up in fermentation products other than lactate. Addition...... of even minute amounts of oxygen increased the yield of biomass on glucose by more than 10% compared to that obtained under anaerobic conditions and had a dramatic impact on catabolic enzyme activities and hence on the distribution of carbon at the pyruvate branch point. Increasing aeration caused carbon...... dioxide and acetate to replace formate and ethanol as catabolic end products while hardly affecting the production of either acetoin or lactate. The negative impact of oxygen on the synthesis of pyruvate formate lyase was confirmed. Moreover, oxygen was shown to down regulate the protein level of alcohol...

  11. 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.

  12. 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.

  13. Book review. Conoscere gli animali familiari. Francesca Bellini, Alessia Liverini, Vincenzo Rosa

    Directory of Open Access Journals (Sweden)

    Manuel Graziani

    2014-03-01

    Full Text Available Conoscere gli animali familiari è la settima uscita della collana diretta da Paolo Polidori "produzioni animali e sicurezza alimentare" sulla ricerca nell'ambito della nutrizione e alimentazione animale, zootecnia, ispezione degli alimenti di origine animale, clinica medica e parassitologia veterinaria con risvolti di natura tecnica, scientifica e pratica. Il volume, redatto da medici veterinari in servizio presso differenti Aziende Sanitarie italiane, è un sintetico manuale su domesticazione, cura sanitaria, etnografia e addestramento del proprio cane (o gatto. Gli autori partono dall'assunto che i proprietari scelgono il cane per lo più sulla base del gusto visivo o sulla consuetudine tramandata in famiglia, senza un'esaustiva conoscenza degli aspetti riguardanti l'origine dell'animale, la sua attitudine prevalente, le sue patologie ricorrenti e le eventuali predisposizioni genetiche nei confronti di una determinata patologia. Puntano l'accento sin dalle prime battute sul cambiamento culturale che ha modificato anche il rapporto uomo-animale sotto l'aspetto sociale, effettuale e giuridico. L'animale da semplice "res" si è da tempo affermato come un essere diverso ma senziente, quindi destinatario di tutele, con diritti contemplati dalle carte costituzionali di diversi Paesi. Per questo motivo chi detiene un animale domestico deve prepararsi ad un impegno non riducibile al possesso di un oggetto, al punto di risponderne penalmente per eventuali sofferenze fisiche o psicologiche, per l'abbandono (anche solo temporaneo o per l'incuria. Conoscere gli animali familiari fornisce nozioni scientifiche e sanitarie alla portata di tutti, utili soprattutto nelle occasioni in cui i proprietari dovranno recarsi dal veterinario o affrontare visite legate alla profilassi e alle vaccinazioni di routine.

  14. Effect of a probiotic mixed culture on texture profile and sensory performance of Minas fresh cheese in comparison with the traditional products.

    Science.gov (United States)

    Buriti, Flávia C A; Okazaki, Tania Y; Alegro, João H A; Saad, Susana M I

    2007-06-01

    The effect of a mixed probiotic culture on instrumental texture, and on sensorial and related properties of Minas fresh cheese during refrigerated storage was investigated. Three cheese-making trials were prepared: T1, with the traditional type O starter culture (Lactococcus lactis subsp. lactis + L. lactis subsp. cremoris), T2 with only lactic acid and T3, with lactic acid and the probiotic ABT culture (Lactobacillus acidophilus La-5 + Bifidobacterium animalis Bb-12 + Streptococcus thermophilus). Instrumental texture profile analysis and related properties were monitored during storage for up to 21 days. Lb. acidophilus and B. animalis were present in high levels throughout storage of cheeses T3, above 6 log cfu.g(-1), threshold required for probiotic activity, and stimulation of the La-5 growth was observed. Cheeses with added probiotic ABT culture, as well as those made adding lactic acid only, showed to be less brittle and with more favorable sensorial features, due to higher pH values. Results indicated that the use of probiotic ABT culture complementary to lactic acid for the purpose of substituting the type O (Lc. lactis subsp. lactis + Lc. lactis subsp. cremoris) culture, traditionally employed for Minas cheese production, is advantageous.

  15. Book review, Animali da compagnia: tutele – diritti – responsabilità, Elena Bassoli (a cura di

    Directory of Open Access Journals (Sweden)

    Manuel Graziani

    2012-12-01

    Full Text Available L'avvocato, docente universitario e presidente dell'Associazione Nazionale Giuristi Informatici e Forensi, Elena Bassoli, ha curato un manuale che affronta le problematiche relative ai diritti degli animali, approfondendo prima la legislazione internazionale e poi le singole pieghe di quella italiana. Il dato da cui si parte sembra secondario ma, invero, è assai rilevante, ovvero che nel nostro Paese si è passati molto lentamente da una concezione esclusivamente utilitaristica degli animali (tutelati in quanto proprietà di qualcuno all'affermazione dei diritti propri dell'animale in quanto tale.Animali da compagnia: tutele – diritti – responsabilità è utile soprattutto alla luce dei Trattati internazionali (D.U.D.A., Trattato di Amsterdam, Trattato di Lisbona che nel corso degli anni hanno introdotto la tutela dell'animale nelle legislazioni di tutto il mondo. La curatrice e i collaboratori hanno analizzato la recente giurisprudenza sugli animali da compagnia e le varie fonti del diritto nazionale, europeo e internazionale, passando in rassegna le norme di riferimento e indicandone l'applicabilità e le procedure con il fine dichiarato di: "Offrire al lettore uno strumento utile, rigoroso e scritto in modo chiaro e comprensibile anche per chi, per la prima volta, si trovi ad affrontare questa parte del diritto". Il manuale si presenta precipuamente come uno strumento di lavoro per i professionisti che trattano le problematiche relative al mondo degli animali domestici. Va segnalata, in proposito, la chiarezza non solo nell'esposizione dei concetti ma anche nell'architettura editoriale. I 10 capitoli che lo compongono forniscono un inquadramento sistematico delle implicazioni amministrative e penali, con rimandi a diverse note per una maggiore chiarezza del testo: dalle origini del diritto animale (dall'antica Grecia all'animalismo contemporaneo, con in mezzo Medioevo, Rinascimento e Darwinismo passando alla tutela degli animali nell

  16. Animali, uomini, mostri : tenerezze e orrori per un’anima sulla soglia

    OpenAIRE

    Maranini, Anna

    2010-01-01

    A partire dal simbolo dell’anima come raffi gurato in un’edizione cinquecentesca de l’Acerba di Cecco d’Ascoli, si offrono qui alcune testimonianze di ‘esseri volanti’ che si sono prestati a rappresentare l’anima che oltrepassa un limes, una soglia, a volte nella loro bona pars, a volte nella loro mala pars. Oltre ad associare l’anima ad animali che possiedono ali per natura o ad esseri alati immaginari, la letteratura medievale e rinascimentale ha dotato l’anima di ali anche quando l’ha raff...

  17. Towards Enhanced Galactose Utilization by Lactococcus lactis

    NARCIS (Netherlands)

    Neves, A.R.; Pool, W.; Solopova, A.; Kok, J.; Santos, H; Kuipers, O.P.

    2010-01-01

    Accumulation of galactose in dairy products due to partial lactose fermentation by lactic acid bacteria yields poor-quality products and precludes their consumption by individuals suffering from galactosemia. This study aimed at extending our knowledge of galactose metabolism in Lactococcus lactis,

  18. 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.

  19. Protein export elements from Lactococcus lactis

    NARCIS (Netherlands)

    Perez-Martinez, Gaspar; Kok, Jan; Venema, Gerhardus; Dijl, Jan Maarten van; Smith, Hilda; Bron, Sierd

    Broad-host-range plasmids carrying α-amylase or β-lactamase reporter genes lacking a signal sequence were used to select export elements from Lactococcus lactis chromosomal DNA that could function as signal sequences. Fragments containing such elements were identified by their ability to direct the

  20. 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

  1. 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

  2. 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

  3. Effect of kynurenic acid on the viability of probiotics in vitro.

    Science.gov (United States)

    Dolecka, Jadwiga; Urbanik-Sypniewska, Teresa; Skrzydło-Radomańska, Barbara; Parada-Turska, Jolanta

    2011-01-01

    Probiotics are bacteria that are commercially available as dietary supplements. One of the important properties of probiotics is their ability to survive in the intestine. Recent evidence has identified kynurenic acid (KYNA) as a bactericidal constituent of intestinal fluid. These data led us to study the influence of KYNA on the viability of selected probiotics. We found that KYNA supported the growth of bacteria in the probiotics Acidolac (Lactobacillus acidophilus, Bifidobacterium) and Lakcid Forte (Lactobacillus rhamnosus) or retarded the growth of bacteria from the Acidolac, BioGaia (Lactobacillus reuteri Protectis), Dicoflor (Lactobacillus rhamnosus GG), Lacium (Lactobacillus plantarum) and Trilac (Lactobacillus acidophilus, Lactobacillus delbrueckii subsp. bulgaricus, Bifidobacterium animalis subsp. lactis) probiotics depending on its concentration. KYNA did not affect the viability of bacteria from the probiotic Linex (Lactobacillus acidophilus LA-5, Bifidobacterium animalis subsp. lactis BB-12). Our results suggest a potential role of KYNA in the regulation of bacterial growth in the digestive system.

  4. 13C based proteinogenic amino acid (PAA) and metabolic flux ratio analysis of Lactococcus lactis reveals changes in pentose phosphate (PP) pathway in response to agitation and temperature related stresses

    Science.gov (United States)

    2017-01-01

    Lactococcus lactis subsp. cremoris MG1363 is an important starter culture for dairy fermentation. During industrial fermentations, L. lactis is constantly exposed to stresses that affect the growth and performance of the bacterium. Although the response of L. lactis to several stresses has been described, the adaptation mechanisms at the level of in vivo fluxes have seldom been described. To gain insights into cellular metabolism, 13C metabolic flux analysis and gas chromatography mass spectrometry (GC-MS) were used to measure the flux ratios of active pathways in the central metabolism of L. lactis when subjected to three conditions varying in temperature (30°C, 37°C) and agitation (with and without agitation at 150 rpm). Collectively, the concentrations of proteinogenic amino acids (PAAs) and free fatty acids (FAAs) were compared, and Pearson correlation analysis (r) was calculated to measure the pairwise relationship between PAAs. Branched chain and aromatic amino acids, threonine, serine, lysine and histidine were correlated strongly, suggesting changes in flux regulation in glycolysis, the pentose phosphate (PP) pathway, malic enzyme and anaplerotic reaction catalysed by pyruvate carboxylase (pycA). Flux ratio analysis revealed that glucose was mainly converted by glycolysis, highlighting the stability of L. lactis’ central carbon metabolism despite different conditions. Higher flux ratios through oxaloacetate (OAA) from pyruvate (PYR) reaction in all conditions suggested the activation of pyruvate carboxylate (pycA) in L. lactis, in response to acid stress during exponential phase. Subsequently, more significant flux ratio differences were seen through the oxidative and non-oxidative pentose phosphate (PP) pathways, malic enzyme, and serine and C1 metabolism, suggesting NADPH requirements in response to environmental stimuli. These reactions could play an important role in optimization strategies for metabolic engineering in L. lactis. Overall, the

  5. 13C based proteinogenic amino acid (PAA and metabolic flux ratio analysis of Lactococcus lactis reveals changes in pentose phosphate (PP pathway in response to agitation and temperature related stresses

    Directory of Open Access Journals (Sweden)

    Kamalrul Azlan Azizan

    2017-07-01

    Full Text Available Lactococcus lactis subsp. cremoris MG1363 is an important starter culture for dairy fermentation. During industrial fermentations, L. lactis is constantly exposed to stresses that affect the growth and performance of the bacterium. Although the response of L. lactis to several stresses has been described, the adaptation mechanisms at the level of in vivo fluxes have seldom been described. To gain insights into cellular metabolism, 13C metabolic flux analysis and gas chromatography mass spectrometry (GC-MS were used to measure the flux ratios of active pathways in the central metabolism of L. lactis when subjected to three conditions varying in temperature (30°C, 37°C and agitation (with and without agitation at 150 rpm. Collectively, the concentrations of proteinogenic amino acids (PAAs and free fatty acids (FAAs were compared, and Pearson correlation analysis (r was calculated to measure the pairwise relationship between PAAs. Branched chain and aromatic amino acids, threonine, serine, lysine and histidine were correlated strongly, suggesting changes in flux regulation in glycolysis, the pentose phosphate (PP pathway, malic enzyme and anaplerotic reaction catalysed by pyruvate carboxylase (pycA. Flux ratio analysis revealed that glucose was mainly converted by glycolysis, highlighting the stability of L. lactis’ central carbon metabolism despite different conditions. Higher flux ratios through oxaloacetate (OAA from pyruvate (PYR reaction in all conditions suggested the activation of pyruvate carboxylate (pycA in L. lactis, in response to acid stress during exponential phase. Subsequently, more significant flux ratio differences were seen through the oxidative and non-oxidative pentose phosphate (PP pathways, malic enzyme, and serine and C1 metabolism, suggesting NADPH requirements in response to environmental stimuli. These reactions could play an important role in optimization strategies for metabolic engineering in L. lactis. Overall

  6. 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

  7. Bioprocessing and immobilization of cell envelope proteinases from Lactobacillus delbrueckii subsp. lactis 313, for protein degradation

    OpenAIRE

    Agyei, Dominic

    2017-01-01

    Proteolytic enzymes are a useful class of biomolecules due to their ubiquity and the plethora of physiological roles they play in living systems. These enzymes are esponsible for the breakdown of proteins to peptides and have several applications in food, pharmaceuticals, diagnostics, photographic, waste treatments, bioremediation, and in the textile industry. Cell-envelope proteinases (CEPs) are a special class of industrially relevant extracellular proteolytic enzymes obtained from la...

  8. Light Sensitivity of Lactococcus lactis Thioredoxin Reductase

    DEFF Research Database (Denmark)

    Skjoldager, Nicklas

    such as Staphylococcus aureus (SaTrxR), Streptococcus pyogenes and Bacillus anthracis. A comparative photo-inactivation of TrxR from L. lactis, S. aureus and B. subtilis reveals that SaTrxR and BsTrxR are much less sensitive to light-inactivation than LlTrxR, though SaTrxR exhibited a similar rate of O2 reduction...

  9. 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

    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......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...... on these results and on chromatographic analysis of XOS consumption in BB-12 cultures, a model for XOS utilisation in BB-12 was established. The subsequent phase of the PhD project included extracellular proteome analysis, giving rise to the identification of 86 unique proteins. Of these proteins, 33...

  10. Evaluation of the passage of Lactobacillus gasseri K7 and bifidobacteria from the stomach to intestines using a single reactor model

    Directory of Open Access Journals (Sweden)

    von Ah Ueli

    2009-05-01

    Full Text Available Abstract Background Probiotic bacteria are thought to play an important role in the digestive system and therefore have to survive the passage from stomach to intestines. Recently, a novel approach to simulate the passage from stomach to intestines in a single bioreactor was developed. The advantage of this automated one reactor system was the ability to test the influence of acid, bile salts and pancreatin. Lactobacillus gasseri K7 is a strain isolated from infant faeces with properties making the strain interesting for cheese production. In this study, a single reactor system was used to evaluate the survival of L. gasseri K7 and selected bifidobacteria from our collection through the stomach-intestine passage. Results Initial screening for acid resistance in acidified culture media showed a low tolerance of Bifidobacterium dentium for this condition indicating low survival in the passage. Similar results were achieved with B. longum subsp. infantis whereas B. animalis subsp. lactis had a high survival. These initial results were confirmed in the bioreactor model of the stomach-intestine passage. B. animalis subsp. lactis had the highest survival rate (10% attaining approximately 5 × 106 cfu ml-1 compared to the other tested bifidobacteria strains which were reduced by a factor of up to 106. Lactobacillus gasseri K7 was less resistant than B. animalis subsp. lactis but survived at cell concentrations approximately 1000 times higher than other bifidobacteria. Conclusion In this study, we were able to show that L. gasseri K7 had a high survival rate in the stomach-intestine passage. By comparing the results with a previous study in piglets we could confirm the reliability of our simulation. Of the tested bifidobacteria strains, only B. animalis subsp. lactis showed acceptable survival for a successful passage in the simulation system.

  11. 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

  12. 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. lactis...

  13. 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

  14. 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.

  15. 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

  16. THE EFFECT OF PROBIOTIC FERMENTED MILK THAT INCLUDES BIFIDOBACTERIUM LACTIS CNCM I-2494 ON THE REDUCTION OF GASTROINTESTINAL DISCOMFORT AND SYMPTOMS IN ADULTS: A NARRATIVE REVIEW.

    Science.gov (United States)

    Waitzberg, Dan L; Quilici, Flávio A; Michzputen, Sender; Friche Passos, Maria do Carmo

    2015-08-01

    determine the effectiveness of fermented milk that included Bifidobacterium lactis CNCM I-2429 for reducing gastrointestinal (GI) discomfort in healthy adults. we conducted a systematic literature search to identify studies reporting the use of B. animalis spp. lactis for GI discomfort/comfort in healthy adults. A total of 5329 records were identified, of these 99 full-text articles were assessed. Searches for additional trials were conducted using the names of authors of each identified study and several relevant databases. The study selection was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies were included if they were randomized controlled trials; the included subjects were healthy adults; and the intervention group received B. lactis CNCM I-2494. Studies were excluded if they were non-randomized trials, if they included adults who were not healthy, if they included the use of any other intervention, or if they compared different products without a placebo group. The methodological quality of the studies was evaluated using the Oxford Quality Scale and the Cochrane Concealment Assessment. A meta-analysis was not possible. the search strategy identified two studies that included a total of 538 healthy women, aged 18-60 years, normal weight or overweight (BMI 18-30 kg/m2). GI well-being was significantly improved in the Probiotic group vs. the Control group in one study, with no differences in the other. The percentage of responders for GI well-being was higher in the Probiotic group vs. the Control group in the first study but not in the second. GI symptoms were significantly decreased in the Probiotic group vs. the Control group in both studies. Bowel function was assessed by one study; the stool frequency did not differ between the groups, but a decrease in stool consistency was observed in the Probiotic group but not in the Control group. Possible mechanisms of action (gut motility

  17. Clinical benefits of probiotic canine-derived Bifidobacterium animalis strain AHC7 in dogs with acute idiopathic diarrhea.

    Science.gov (United States)

    Kelley, R L; Minikhiem, Debbie; Kiely, Barry; O'Mahony, Liam; O'Sullivan, David; Boileau, Tom; Park, Jean Soon

    2009-01-01

    This study evaluated the effect of supplementation with canine-derived probiotic Bifidobacterium animalis strain AHC7 (lams Prostora, Procter & Gamble Pet Care) on the resolution rate of acute idiopathic diarrhea in dogs randomly assigned to receive a placebo (n=18) or the probiotic (n=13). Nutritional management with the probiotic fed at 2 x 10(10) CFU/day significantly reduced the time to resolution (3.9 +/- 2.3 versus 6.6 +/- 2.7 days; P dogs that were administered metronidazole (38.5% versus 50.0%) compared with placebo. Probiotic B. animalis AHC7 may provide veterinarians another tool for management of acute diarrhea in dogs.

  18. Behavior and viability of spontaneous oxidative stress-resistant Lactococcus lactis mutants in experimental fermented milk processing.

    Science.gov (United States)

    Oliveira, M N; Almeida, K E; Damin, M R; Rochat, T; Gratadoux, J-J; Miyoshi, A; Langella, P; Azevedo, V

    2009-07-21

    Previously, we isolated two strains of spontaneous oxidative (SpOx2 and SpOx3) stress mutants of Lactococcus lactis subsp cremoris. Herein, we compared these mutants to a parental wild-type strain (J60011) and a commercial starter in experimental fermented milk production. Total solid contents of milk and fermentation temperature both affected the acidification profile of the spontaneous oxidative stress-resistant L. lactis mutants during fermented milk production. Fermentation times to pH 4.7 ranged from 6.40 h (J60011) to 9.36 h (SpOx2); V(max) values were inversely proportional to fermentation time. Bacterial counts increased to above 8.50 log(10) cfu/mL. The counts of viable SpOx3 mutants were higher than those of the parental wild strain in all treatments. All fermented milk products showed post-fermentation acidification after 24 h of storage at 4 degrees C; they remained stable after one week of storage.

  19. Administration of Lactococcus lactis strain Plasma induces maturation of plasmacytoid dendritic cells and protection from rotavirus infection in suckling mice.

    Science.gov (United States)

    Jounai, Kenta; Sugimura, Tetsu; Morita, Yuji; Ohshio, Konomi; Fujiwara, Daisuke

    2018-03-01

    Lactococcus lactis subsp. lactis JCM 5805 (LC-Plasma) is a strain of lactic acid bacteria (LAB) that activates murine and human plasmacytoid dendritic cells (pDCs) to express interferons (IFNs). Oral administration of LC-Plasma drastically decreased fatality levels caused by parainfluenza virus infection in a murine model. In this study, we investigated the anti-viral effects of oral administration of LC-Plasma using a suckling mouse model of rhesus rotavirus (RV) infection. LC-Plasma-fed mice showed improvement in retardation of body weight gain, fecal scores, and a reduction in RV titer in the feces when compared to control mice. The mechanism of anti-viral effects elicited by LC-Plasma administration was investigated using naive mice: in the LC-Plasma -fed mice, lamina propria (LP) pDCs resident in the small intestine were significantly matured and the proportion of pDCs was increased. The expression levels of anti-viral factors induced by IFNs, such as Isg15, Mx1, Oasl2 and Viperin, and an anti-bacterial factor Reg3γ, were up-regulated in the small intestinal epithelial cells (IECs) of LC-Plasma-fed mice. The specific LAB strain may affect the anti-viral immunological profile of IECs via maturation of LP pDCs, leading to protection from RV virus infection in vivo. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Production of spent mushroom substrate hydrolysates useful for cultivation of Lactococcus lactis by dilute sulfuric acid, cellulase and xylanase treatment.

    Science.gov (United States)

    Qiao, Jian-Jun; Zhang, Yan-Fei; Sun, Li-Fan; Liu, Wei-Wei; Zhu, Hong-Ji; Zhang, Zhijun

    2011-09-01

    Spent mushroom substrate (SMS) was treated with dilute sulfuric acid followed by cellulase and xylanase treatment to produce hydrolysates that could be used as the basis for media for the production of value added products. A L9 (3(4)) orthogonal experiment was performed to optimize the acid treatment process. Pretreatment with 6% (w/w) dilute sulfuric acid at 120°C for 120 min provided the highest reducing sugar yield of 267.57 g/kg SMS. No furfural was detected in the hydrolysates. Exposure to 20PFU of cellulase and 200 XU of xylanase per gram of pretreated SMS at 40°C resulted in the release of 79.85 g/kg or reducing sugars per kg acid pretreated SMS. The dilute sulfuric acid could be recycled to process fresh SMS four times. SMS hydrolysates neutralized with ammonium hydroxide, sodium hydroxide, or calcium hydroxide could be used as the carbon source for cultivation of Lactococcus lactis subsp. lactis W28 and a cell density of 2.9×10(11)CFU/mL could be obtained. The results provide a foundation for the development of value-added products based on SMS. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. I mostri dell’Occidente medievale: fonti e diffusione di razze umane mostruose, ibridi ed animali fantastici

    OpenAIRE

    Sebenico, Sara

    2005-01-01

    Nell'Occidente medievale i mostri sono ovunque: nei bestiari, nella letteratura di viaggio, nelle enciclopedie, nei romanzi, ma anche nei sermoni recitati in Chiesa. I mostri sono diffusissimi nell'arte, in particolare nel periodo romanico e gotico nella scultura religiosa e nella miniatura. I mostri nel Medioevo comprendono le razze umane mostruose, come cinocefali e acefali, gli animali fantastici come grifone, basilisco, unicorno e gli ibridi, ma c'erano anche ibridi vegetali, come l'anatr...

  2. 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.

  3. 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

  4. Identification of Mycobacterium avium subsp. hominissuis Isolated From Drinking Water

    Science.gov (United States)

    Mycobacterium avium (MA) is divided into four subspecies based primarily on host-range and consists of MA subsp. avium (birds), MA subsp. silvaticum (wood pigeons), MA subsp. paratuberculosis (broad, poorly-defined host range), and the recently described MA subsp. hominissuis (hu...

  5. Antimicrobial potential of commercial silver nanoparticles and the characterization of their physical properties toward probiotic bacteria isolated from fermented milk products.

    Science.gov (United States)

    Mikiciuk, Jakub; Mikiciuk, Ewa; Wrońska, Anna; Szterk, Arkadiusz

    2016-01-01

    The application of nanotechnology in the agriculture and food sector is relatively recent compared to its usage in drug delivery or pharmaceuticals. Therefore, this paper presents a study of the effect of silver nanoparticles on probiotic bacteria based on the example of Lactobacillus acidophilus LA-5, Bifidobacterium animalis subsp. lactis BB-12 and Streptococcus thermophilus ST-Y31 isolated from fermented milk products. Probiotic bacteria are one of the most crucial groups of bacteria for the food industry, because of their claimed health-promoting properties. Studies have shown that the type and concentration of silver nanoparticle solutions have a significant impact on the tested probiotic bacteria which are profitable for the digestive system. In the presence of all tested silver nanoparticles, St. thermophilus ST-Y31 growth was inhibited significantly by the dilution method as opposed to the disk-diffusion method. Both the disk-diffusion and the dilution methods showed no significant differences between L. acidophilus LA-5 and B. animalis subsp. lactis BB-12. The concentrations 2 μg mL(-1) and 0.25 μg mL(-1) had the highest antibacterial activity and statistically significant impacts on the tested probiotic strains. To our knowledge, this is the first report on potential antimicrobial effect of nanosilver against the health-promoting probiotic bacteria L. acidophilus LA-5, B. animalis subsp. lactis BB-12 and St. thermophilus ST-Y31 isolated from fermented milk products.

  6. A novel non-dairy beverage from durian pulp fermented with selected probiotics and yeast.

    Science.gov (United States)

    Lu, Yuyun; Putra, Satya Dwi; Liu, Shao-Quan

    2018-01-16

    This study investigated the effects of sequential inoculation (Seq-I) of Bifidobacterium animalis subsp. lactis or Lactobacillus casei with yeast Williopsis saturnus on durian pulp fermentation. Seq-I of W. saturnus following B. animalis subsp. lactis did not bring about any significant differences compared to the B. animalis subsp. lactis monoculture due to the sharp early death of W. saturnus soon after inoculation. However, Seq-I of W. saturnus significantly enhanced the survival of L. casei and improved the utilization of fructose and glucose compared to L. casei monoculture. In addition, there were significant differences in the metabolism of organic acids especially for lactic acid and succinic acid. Furthermore, Seq-I produced significantly higher levels of volatile compounds including alcohols (ethanol and 2-phenylethyl alcohol) and acetate esters (2-phenylethyl acetate, isoamyl acetate and ethyl acetate), which would positively contribute to the flavour notes. Although the initial volatile sulphur compounds were reduced to trace levels after fermentation, but the durian odour still remained. This study suggests that the use of probiotics and W. saturnus to ferment durian pulp could act as a potential avenue to develop a novel non-dairy durian-based functional beverage to deliver probiotics. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Solid-state fermentation of whole oats to yield a synbiotic food rich in lactic acid bacteria and prebiotics.

    Science.gov (United States)

    Zhang, Nan; Li, Dan; Zhang, XiQing; Shi, Yan; Wang, HaiKuan

    2015-08-01

    This study developed a synbiotic food through the fermentation of whole oat flour with Lactobacillus plantarum TK9 and Bifidobacterium animalis subsp. lactis V9. The physicochemical properties, changes in ingredients and peptide molecular weight distributions were determined during the whole oat fermentation. The highest viable counts of the fermented oats were 2.85 × 10(9) CFU g(-1) (L. plantarum TK9) and 3.17 × 10(8) CFU g(-1) (Bif. animalis subsp. lactis V9), with the titratable acidity increased to 10.01 and 8.40 mL at the end of the fermentation. By comparing the nutrition compositions between the fermented and non-fermented oat flour, we found that there was almost no change in the soluble dietary fiber and β-glucan content. However, the amounts of free amino nitrogen increased from 110.84 to 154.62 mg per 100 g (L. plantarum TK9) and 82.16 to 104.83 mg per 100 g (Bif. animalis subsp. lactis V9). The levels of oat peptides with molecular weights less than 6000 Da increased by 4.4 and 5.96%, respectively. The results suggest that the fermented whole oat flour has good potential for application in the production of a novel synbiotic food rich in lactic acid bacteria and β-glucan prebiotics.

  8. INFLUENCE OF DRINKING A PROBIOTIC FERMENTED MILK BEVERAGE CONTAINING BIFIDOBACTERIUM ANIMALIS ON THE SYMPTOMS OF CONSTIPATION.

    Science.gov (United States)

    Moreira, Thaís Rodrigues; Leonhardt, Daiane; Conde, Simara Rufatto

    2017-01-01

    Constipation is a chronic problem in many patients all over the world. - To evaluate the effect of consumption of a probiotic fermented milk beverage containing Bifidobacterium animalis on the symptoms of constipation. - This randomized, double-blind controlled trial included 49 female patients aged 20 to 50 years and diagnosed with constipation according to the ROME III criteria (Diagnostic Criteria for Functional Gastrointestinal Disorders) and the Bristol Stool Form Scale. The patients were randomized into two groups: the intervention group received the probiotic fermented milk beverage and the control group received non-probiotic milk. Participants were instructed to ingest 150 mL of the beverages during 60 days. At the end of this period, patients were assessed again by the ROME III criteria and Bristol scale. The Wilcoxon test was used to evaluate pre and post-intervention results of the ROME III criteria and Bristol scale. The statistical significance level was considered as 5% ( P ≤0.05). - The intervention group showed improvement in the following criteria: straining during a bowel movement ( P Bristol scale results ( P Bristol scale results ( P Bristol scale. - The results show that the consumption of milk resulted in the improvement of constipation symptoms, regardless of the probiotic culture.

  9. 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.

  10. 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.

  11. 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.

  12. Glutathione attenuates uranyl toxicity in Lactococcus lactis

    International Nuclear Information System (INIS)

    Fahmy, Karim; Oertel, Jana; Solioz, M.

    2017-01-01

    We investigated the role of intracellular glutathione (GSH), which in a large number of taxa plays a role in the protection against the toxicity of heavy metals. Anaerobically grown Lactococcus lactis containing an inducible GSH synthesis pathway was used as a model organism allowing the study of GSH-dependent uranyl detoxification without interference from additional reactive oxygen species. Microcalorimetric measurements of the metabolic heat showed that intracellular GSH attenuates the toxicity of uranium at a concentration in the range of 10-150 μM. Isothermal titration calorimetry revealed the endothermic binding of U(VI) to the carboxyl group(s) of GSH. The data indicate that the primary detoxifying mechanism is the intracellular sequestration of carboxyl-coordinated U(VI) into an insoluble complex with GSH.

  13. Glutathione attenuates uranyl toxicity in Lactococcus lactis

    Energy Technology Data Exchange (ETDEWEB)

    Fahmy, Karim; Oertel, Jana [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Biophysics; Obeid, M. [Technische Univ. Dresden (Germany); Solioz, M. [Bern Univ. (Switzerland)

    2017-06-01

    We investigated the role of intracellular glutathione (GSH), which in a large number of taxa plays a role in the protection against the toxicity of heavy metals. Anaerobically grown Lactococcus lactis containing an inducible GSH synthesis pathway was used as a model organism allowing the study of GSH-dependent uranyl detoxification without interference from additional reactive oxygen species. Microcalorimetric measurements of the metabolic heat showed that intracellular GSH attenuates the toxicity of uranium at a concentration in the range of 10-150 μM. Isothermal titration calorimetry revealed the endothermic binding of U(VI) to the carboxyl group(s) of GSH. The data indicate that the primary detoxifying mechanism is the intracellular sequestration of carboxyl-coordinated U(VI) into an insoluble complex with GSH.

  14. Lactococcus lactis spp lactis infection in infants with chronic diarrhea: two cases report and literature review in children.

    Science.gov (United States)

    Karaaslan, Ayse; Soysal, Ahmet; Kepenekli Kadayifci, Eda; Yakut, Nurhayat; Ocal Demir, Sevliya; Akkoc, Gulsen; Atici, Serkan; Sarmis, Abdurrahman; Ulger Toprak, Nurver; Bakir, Mustafa

    2016-03-31

    Lactococcus lactis is a gram-positive, facultative anaerobic coccus that is occasionally isolated from human mucocutaneous surfaces such as the intestines. It is used in the dairy industry for milk acidification and is mostly nonpathogenic in immunocompetent humans, however a number of cases of infection with L. lactis have been reported in recent years. In this article, we describe two cases of infection due to L. lactis in patients with chronic diarrhea. The first case is a five-month-old boy who was operated on for volvulus on his first day of life and had ileostomy with subsequent diagnosis of chronic diarrhea and bacteremia due to L. Lactis. The second case is a six-month-old girl with the diagnosis of chronic diarrhea that developed after a catheter-related bloodstream infection. Both of the infections due to L. Lactis spp lactis were successfully treated with intravenous vancomycin therapy. Although Lactococcus species is mostly known as nonpathogenic, it should be kept in mind as a potential pathogen, especially in patients with gastrointestinal disorders.

  15. Methane production in the biosphere; La produzione di metano nella biosfera: il ruolo degli animali da allevamento

    Energy Technology Data Exchange (ETDEWEB)

    Sauvant, D. [Stazione di Nutrizione e Alimentazione (Italy)

    1999-04-01

    Methane is a greenhouse gas. A part of methane production is of agricultural origin. The emissions related to animal organisms are evaluated and discussed. [Italian] Il metano e' una molecola che contribuisce all'effetto serra e alle conseguenze climatiche che ne derivano. Una parte di metano e' di orgine agricola, legata in particolare alla produzione animale. Questo breve documento vuole focalizzare le conoscenze su quest'ultimo aspetto, limitandosi alle emissioni attribuibili agli organismi animali, escludendo pero' i loro rifiuti.

  16. Physical and physicochemical stability evaluation of cosmetic formulations containing soybean extract fermented by Bifidobacterium animalis

    Directory of Open Access Journals (Sweden)

    Rafael Pinto Vieira

    2009-09-01

    Full Text Available Peel off facial masks, based on polyvinyl alcohol (PVA, are formulations that, after application and drying, form an occlusive film over the face. After removing, they provide cleanness, tensor and moisturizing effects, removing dead cells, residues and other materials deposited on the stratum corneous. The soybean extract fermented by Bifidobacterium animalis has sugars, amino acids, peptides, proteins and free isoflavonoids in high concentrations, when compared to the unfermented extract, providing benefits to the cosmetic formulations like anti-aging effect, moisture, tensor action and emollience. The cosmetic bases of peel off facial masks, added with 5.0% w/w of fermented soybean extract, were submitted to Preliminary and Accelerated Stability Studies. Eight (8 preparations were evaluated in several conditions of temperature (-10.0, 5.0, 22.0 and 45.0 ºC and time (maximum of 15 days, comparing the results with the initial condition (48 h after preparation. The variables observed were: organoleptic characteristics, pH and appearing viscosity value and film drying time. The preparation containing 17.0% w/w of PVA and 0.5% w/w of guar gum was selected between the eight preparations initially prepared, because it presented the best performance in the stability test, being recommended storage at low temperatures (5.0 ºC.As máscaras faciais peel off a base de álcool polivinílico (PVA são formulações que, após a aplicação e secagem, formam um filme oclusivo sobre a face e, após sua remoção, conferem limpeza, ação tensora e hidratação à pele, retirando células mortas do estrato córneo, resíduos e outros materiais depositados. O extrato de soja fermentado por Bifidobacterium animalis possui açúcares, aminoácidos, peptídeos, e alto teor de isoflavonas na forma livre, quando comparado ao leite não fermentado, propiciando benefícios às formulações cosméticas, como ação antienvelhecimento, hidratação, efeito tensor e

  17. INFLUENCE OF DRINKING A PROBIOTIC FERMENTED MILK BEVERAGE CONTAINING BIFIDOBACTERIUM ANIMALIS ON THE SYMPTOMS OF CONSTIPATION

    Directory of Open Access Journals (Sweden)

    Thaís Rodrigues MOREIRA

    2017-05-01

    Full Text Available ABSTRACT BACKGROUND Constipation is a chronic problem in many patients all over the world. OBJECTIVE - To evaluate the effect of consumption of a probiotic fermented milk beverage containing Bifidobacterium animalis on the symptoms of constipation. METHODS - This randomized, double-blind controlled trial included 49 female patients aged 20 to 50 years and diagnosed with constipation according to the ROME III criteria (Diagnostic Criteria for Functional Gastrointestinal Disorders and the Bristol Stool Form Scale. The patients were randomized into two groups: the intervention group received the probiotic fermented milk beverage and the control group received non-probiotic milk. Participants were instructed to ingest 150 mL of the beverages during 60 days. At the end of this period, patients were assessed again by the ROME III criteria and Bristol scale. The Wilcoxon test was used to evaluate pre and post-intervention results of the ROME III criteria and Bristol scale. The statistical significance level was considered as 5% ( P ≤0.05. RESULTS - The intervention group showed improvement in the following criteria: straining during a bowel movement ( P <0.001, feeling of incomplete evacuation ( P <0.001 and difficulty in passing stool ( P <0.014, in addition to Bristol scale results ( P <0.001. In the control group, improvements were observed in the following criteria: straining during a bowel movement ( P <0.001, feeling of incomplete evacuation ( P <0.001 and difficulty in passing stool ( P <0.025, in addition to Bristol scale results ( P <0.001. No statistically significant post-intervention differences were observed between the two groups for the Rome III criteria and Bristol scale. CONCLUSION - The results show that the consumption of milk resulted in the improvement of constipation symptoms, regardless of the probiotic culture.

  18. Transfer of several phytopathogenic Pseudomonas species to Acidovorax as Acidovorax avenae subsp. avenae subsp. nov., comb. nov., Acidovorax avenae subsp. citrulli, Acidovorax avenae subsp. cattleyae, and Acidovorax konjaci.

    Science.gov (United States)

    Willems, A; Goor, M; Thielemans, S; Gillis, M; Kersters, K; De Ley, J

    1992-01-01

    DNA-rRNA hybridizations, DNA-DNA hybridizations, polyacrylamide gel electrophoresis of whole-cell proteins, and a numerical analysis of carbon assimilation tests were carried out to determine the relationships among the phylogenetically misnamed phytopathogenic taxa Pseudomonas avenae, Pseudomonas rubrilineans, "Pseudomonas setariae," Pseudomonas cattleyae, Pseudomonas pseudoalcaligenes subsp. citrulli, and Pseudomonas pseudoalcaligenes subsp. konjaci. These organisms are all members of the family Comamonadaceae, within which they constitute a separate rRNA branch. Only P. pseudoalcaligenes subsp. konjaci is situated on the lower part of this rRNA branch; all of the other taxa cluster very closely around the type strain of P. avenae. When they are compared phenotypically, all of the members of this rRNA branch can be differentiated from each other, and they are, as a group, most closely related to the genus Acidovorax. DNA-DNA hybridization experiments showed that these organisms constitute two genotypic groups. We propose that the generically misnamed phytopathogenic Pseudomonas species should be transferred to the genus Acidovorax as Acidovorax avenae and Acidovorax konjaci. Within Acidovorax avenae we distinguished the following three subspecies: Acidovorax avenae subsp. avenae, Acidovorax avenae subsp. cattleyae, and Acidovorax avenae subsp. citrulli. Emended descriptions of the new taxa are presented.

  19. 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

  20. 21 CFR 184.1985 - Aminopeptidase enzyme preparation derived from lactococcus lactis.

    Science.gov (United States)

    2010-04-01

    ... lactococcus lactis. 184.1985 Section 184.1985 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Aminopeptidase enzyme preparation derived from lactococcus lactis. (a) Aminopeptidase enzyme preparation is derived from the nonpathogenic and nontoxicogenic bacterium Lactococcus lactis (previously named...

  1. Impact of osmotic stress on protein diffusion in Lactococcus lactis.

    Science.gov (United States)

    Mika, Jacek T; Schavemaker, Paul E; Krasnikov, Victor; Poolman, Bert

    2014-11-01

    We measured translational diffusion of proteins in the cytoplasm and plasma membrane of the Gram-positive bacterium Lactococcus lactis and probed the effect of osmotic upshift. For cells in standard growth medium the diffusion coefficients for cytosolic proteins (27 and 582 kDa) and 12-transmembrane helix membrane proteins are similar to those in Escherichia coli. The translational diffusion of GFP in L. lactis drops by two orders of magnitude when the medium osmolality is increased by ∼ 1.9 Osm, and the decrease in mobility is partly reversed in the presence of osmoprotectants. We find a large spread in diffusion coefficients over the full population of cells but a smaller spread if only sister cells are compared. While in general the diffusion coefficients we measure under normal osmotic conditions in L. lactis are similar to those reported in E. coli, the decrease in translational diffusion upon osmotic challenge in L. lactis is smaller than in E. coli. An even more striking difference is that in L. lactis the GFP diffusion coefficient drops much more rapidly with volume than in E. coli. We discuss these findings in the light of differences in turgor, cell volume, crowding and cytoplasmic structure of Gram-positive and Gram-negative bacteria. © 2014 John Wiley & Sons Ltd.

  2. Effects of the Food Manufacturing Chain on the Viability and Functionality of Bifidobacterium animalis through Simulated Gastrointestinal Conditions.

    Directory of Open Access Journals (Sweden)

    Pattra Charnchai

    Full Text Available The viability and functionality of probiotics may be influenced by industrial production processes resulting in a decrease in probiotic efficiency that benefit the health of humans. This study aimed to investigate the probiotic characteristics of Bifidobacterium strains isolated from fecal samples of healthy Thai infants. In the present work, three local strains (BF014, BF052, and BH053 belonging to Bifidobacterium animalis showed a great resistance against conditions simulating the gastrointestinal tract. Among these, B. animalis BF052 possessed considerable probiotic properties, including high acid and bile tolerance, strong adhesion capability to Caco-2 cells, and inhibitory activity against pathogens including Salmonella typhimurium and Vibrio cholerae. This strain also exhibited a high survival rate compared to commercial strains during storage in a wide variety of products, including pasteurized milk, soy milk, drinking yogurt, and orange juice. The impact of food processing processes as well as the freeze-drying process, storage of freeze-dried powders, and incorporation of freeze-dried cells in food matrix on probiotic properties was also determined. The stability of the probiotic properties of the BF052 strain was not affected by food processing chain, especially its resistance in the simulated gastrointestinal conditions and its adherence ability to Caco-2 cells. It indicates that it satisfies the criteria as a potential probiotic and may be used as an effective probiotic starter in food applications.

  3. Effects of the Food Manufacturing Chain on the Viability and Functionality of Bifidobacterium animalis through Simulated Gastrointestinal Conditions

    Science.gov (United States)

    Jantama, Sirima Suvarnakuta; Prasitpuriprecha, Chutinun; Kanchanatawee, Sunthorn

    2016-01-01

    The viability and functionality of probiotics may be influenced by industrial production processes resulting in a decrease in probiotic efficiency that benefit the health of humans. This study aimed to investigate the probiotic characteristics of Bifidobacterium strains isolated from fecal samples of healthy Thai infants. In the present work, three local strains (BF014, BF052, and BH053) belonging to Bifidobacterium animalis showed a great resistance against conditions simulating the gastrointestinal tract. Among these, B. animalis BF052 possessed considerable probiotic properties, including high acid and bile tolerance, strong adhesion capability to Caco-2 cells, and inhibitory activity against pathogens including Salmonella typhimurium and Vibrio cholerae. This strain also exhibited a high survival rate compared to commercial strains during storage in a wide variety of products, including pasteurized milk, soy milk, drinking yogurt, and orange juice. The impact of food processing processes as well as the freeze-drying process, storage of freeze-dried powders, and incorporation of freeze-dried cells in food matrix on probiotic properties was also determined. The stability of the probiotic properties of the BF052 strain was not affected by food processing chain, especially its resistance in the simulated gastrointestinal conditions and its adherence ability to Caco-2 cells. It indicates that it satisfies the criteria as a potential probiotic and may be used as an effective probiotic starter in food applications. PMID:27333286

  4. Effects of the Food Manufacturing Chain on the Viability and Functionality of Bifidobacterium animalis through Simulated Gastrointestinal Conditions.

    Science.gov (United States)

    Charnchai, Pattra; Jantama, Sirima Suvarnakuta; Prasitpuriprecha, Chutinun; Kanchanatawee, Sunthorn; Jantama, Kaemwich

    2016-01-01

    The viability and functionality of probiotics may be influenced by industrial production processes resulting in a decrease in probiotic efficiency that benefit the health of humans. This study aimed to investigate the probiotic characteristics of Bifidobacterium strains isolated from fecal samples of healthy Thai infants. In the present work, three local strains (BF014, BF052, and BH053) belonging to Bifidobacterium animalis showed a great resistance against conditions simulating the gastrointestinal tract. Among these, B. animalis BF052 possessed considerable probiotic properties, including high acid and bile tolerance, strong adhesion capability to Caco-2 cells, and inhibitory activity against pathogens including Salmonella typhimurium and Vibrio cholerae. This strain also exhibited a high survival rate compared to commercial strains during storage in a wide variety of products, including pasteurized milk, soy milk, drinking yogurt, and orange juice. The impact of food processing processes as well as the freeze-drying process, storage of freeze-dried powders, and incorporation of freeze-dried cells in food matrix on probiotic properties was also determined. The stability of the probiotic properties of the BF052 strain was not affected by food processing chain, especially its resistance in the simulated gastrointestinal conditions and its adherence ability to Caco-2 cells. It indicates that it satisfies the criteria as a potential probiotic and may be used as an effective probiotic starter in food applications.

  5. 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

  6. 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

  7. Experimental determination of control of glycolysis in Lactococcus lactis

    DEFF Research Database (Denmark)

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

    2002-01-01

    and below the wild-type level. We review a genetic approach that is well suited for both Metabolic Optimization and Metabolic Control Analysis and studies on the importance of a number of glycolytic enzymes for metabolic fluxes in Lactococcus lactis. The glycolytic enzymes phosphofructokinase (PFK......), 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...

  8. 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...... the expression level of certain genes in glycolysis and fermentation pathways, the levels of the cofactors NADH, NAD+, ATP and ADP, the balance between catabolism and anabolism, etc. In this project, we studied the mixed-acid fermentation of L. lactis by (i) examining the roles of the enzymes in the mixed...

  9. Discovery of novel small molecule modulators of Clavibacter michiganensis subsp. michiganensis

    Directory of Open Access Journals (Sweden)

    Xiulan eXu

    2015-10-01

    Full Text Available Clavibacter michiganensis subsp. michiganensis (Cmm is a Gram-positive seed-transmitted bacterial phytopathogen responsible for substantial economic losses by adversely affecting tomato production worldwide. A high-throughput, cell-based screen was adapted to identify novel small molecule growth inhibitors to serve as leads for future bactericide development. A library of 4,182 compounds known to be bioactive against Saccharomyces cerevisiae was selected for primary screening against Cmm wild-type strain C290 for whole-cell growth inhibition. Four hundred sixty-eight molecules (11.2% hit rate were identified as bacteriocidal or bacteriostatic against Cmm at 200 M. Seventy-seven candidates were selected based on Golden Triangle analyses for secondary screening. Secondary screens showed that several of these candidates were strain-selective. Several compounds were inhibitory to multiple Cmm strains as well as Bacillus subtilis, but not Pseudomonas fluorescens, Mitsuaria sp., Lysobacter enzymogenes, Lactobacillus rhamnosus, Bifidobacter animalis, or Escherichia coli. Most of the compounds were not phytotoxic and did not show overt host toxicity. Using a novel 96-well bioluminescent Cmm seedling infection assay, we assessed effects of selected compounds on pathogen infection. The 12 most potent novel molecules were identified by compiling the scores from all secondary screens combined with the reduction of pathogen infection in planta. When tested for ability to develop resistance to the top-12 compounds, no resistant Cmm were recovered, suggesting that the discovered compounds are unlikely to induce resistance. In conclusion, here we report top-12 compounds that provide chemical scaffolds for future Cmm-specific bactericide development.

  10. Discovery of novel small molecule modulators of Clavibacter michiganensis subsp. michiganensis.

    Science.gov (United States)

    Xu, Xiulan; Kumar, Anand; Deblais, Loïc; Pina-Mimbela, Ruby; Nislow, Corey; Fuchs, James R; Miller, Sally A; Rajashekara, Gireesh

    2015-01-01

    Clavibacter michiganensis subsp. michiganensis (Cmm) is a Gram-positive seed-transmitted bacterial phytopathogen responsible for substantial economic losses by adversely affecting tomato production worldwide. A high-throughput, cell-based screen was adapted to identify novel small molecule growth inhibitors to serve as leads for future bactericide development. A library of 4,182 compounds known to be bioactive against Saccharomyces cerevisiae was selected for primary screening against Cmm wild-type strain C290 for whole-cell growth inhibition. Four hundred sixty-eight molecules (11.2% hit rate) were identified as bacteriocidal or bacteriostatic against Cmm at 200 μM. Seventy-seven candidates were selected based on Golden Triangle analyses for secondary screening. Secondary screens showed that several of these candidates were strain-selective. Several compounds were inhibitory to multiple Cmm strains as well as Bacillus subtilis, but not to Pseudomonas fluorescens, Mitsuaria sp., Lysobacter enzymogenes, Lactobacillus rhamnosus, Bifidobacterium animalis, or Escherichia coli. Most of the compounds were not phytotoxic and did not show overt host toxicity. Using a novel 96-well bioluminescent Cmm seedling infection assay, we assessed effects of selected compounds on pathogen infection. The 12 most potent novel molecules were identified by compiling the scores from all secondary screens combined with the reduction of pathogen infection in planta. When tested for ability to develop resistance to the top-12 compounds, no resistant Cmm were recovered, suggesting that the discovered compounds are unlikely to induce resistance. In conclusion, here we report top-12 compounds that provide chemical scaffolds for future Cmm-specific bactericide development.

  11. 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...

  12. Disruption of a Transcriptional Repressor by an Insertion Sequence Element Integration Leads to Activation of a Novel Silent Cellobiose Transporter in Lactococcus lactis MG1363.

    Science.gov (United States)

    Solopova, Ana; Kok, Jan; Kuipers, Oscar P

    2017-12-01

    Lactococcus lactis subsp. cremoris strains typically carry many dairy niche-specific adaptations. During adaptation to the milk environment these former plant strains have acquired various pseudogenes and insertion sequence elements indicative of ongoing genome decay and frequent transposition events in their genomes. Here we describe the reactivation of a silenced plant sugar utilization cluster in an L. lactis MG1363 derivative lacking the two main cellobiose transporters, PtcBA-CelB and PtcBAC, upon applying selection pressure to utilize cellobiose. A disruption of the transcriptional repressor gene llmg_1239 by an insertion sequence (IS) element allows expression of the otherwise silent novel cellobiose transporter Llmg_1244 and leads to growth of mutant strains on cellobiose. Llmg_1239 was labeled CclR, for c ellobiose cl uster r epressor. IMPORTANCE Insertion sequences (ISs) play an important role in the evolution of lactococci and other bacteria. They facilitate DNA rearrangements and are responsible for creation of new genetic variants with selective advantages under certain environmental conditions. L. lactis MG1363 possesses 71 copies in a total of 11 different types of IS elements. This study describes yet another example of an IS-mediated adaptive evolution. An integration of IS 981 or IS 905 into a gene coding for a transcriptional repressor led to activation of the repressed gene cluster coding for a plant sugar utilization pathway. The expression of the gene cluster allowed assembly of a novel cellobiose-specific transporter and led to cell growth on cellobiose. Copyright © 2017 American Society for Microbiology.

  13. Proteolysis in goat "coalho" cheese supplemented with probiotic lactic acid bacteria.

    Science.gov (United States)

    Bezerra, Taliana Kênia Alves; de Araujo, Ana Rita Ribeiro; do Nascimento, Edilza Santos; de Matos Paz, José Eduardo; Gadelha, Carlos Alberto; Gadelha, Tatiane Santi; Pacheco, Maria Teresa Bertoldo; do Egypto Queiroga, Rita de Cássia Ramos; de Oliveira, Maria Elieidy Gomes; Madruga, Marta Suely

    2016-04-01

    This study aimed to analyse the proteolytic effects of adding isolated and combined probiotic strains to goat "coalho" cheese. The cheeses were: QS - with culture Start, composed by Lactococcus lactis subsp. lactis and L. lactis subsp. cremoris (R704); QLA - with Lactobacillus acidophilus (LA-5); QLP - with Lactobacillus paracasei subsp. paracasei (L. casei 01); QB - with Bifidobacterium animalis subsp. lactis (BB 12); and QC, co-culture with the three probiotic microorganisms. The cheeses were analysed during 28 days of storage at 10°C. The probiotic cell count was higher than 6.5 and 7 log colony-forming units (CFU) g(-1) of cheese at the 1st and 28th days of storage, respectively. The addition of co-culture influenced (pcheese and resulted in a higher content of soluble protein and release of amino acids at the 1st day after processing. However, over all 28 days, the cheese supplemented with Bifidobacterium lactis in its isolated form showed the highest proteolytic activity, particularly in the hydrolysis of the alpha-s2 and kappa-casein fractions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. 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

  15. 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

  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 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.

  17. 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.

  18. 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

  19. 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...

  20. Recombinant Lactococcus lactis fails to secrete bovine chymosine

    Science.gov (United States)

    Luerce, Tessália Diniz; Azevedo, Marcela Santiago Pacheco; LeBlanc, Jean Guy; Azevedo, Vasco; Miyoshi, Anderson; Pontes, Daniela Santos

    2014-01-01

    Bovine chymosin is an important milk-clotting agent used in the manufacturing of cheeses. Currently, the production of recombinant proteins by genetically modified organisms is widespread, leading to greatly reduced costs. Lactococcus (L.) lactis, the model lactic acid bacterium, was considered a good candidate for heterologous chymosin production for the following reasons: (1) it is considered to be a GRAS (generally regarded as safe) microorganism, (2) only one protease is present on its surface, (3) it can secrete proteins of different sizes, and (4) it allows for the direct production of protein in fermented food products. Thus, three genetically modified L. lactis strains were constructed to produce and target the three different forms of bovine chymosin, prochymosin B, chymosin A and chymosin B to the extracellular medium. Although all three proteins were stably produced in L. lactis, none of the forms were detected in the extracellular medium or showed clotting activity in milk. Our hypothesis is that this secretion deficiency and lack of clotting activity can be explained by the recombinant protein being attached to the cell envelope. Thus, the development of other strategies is necessary to achieve both production and targeting of chymosin in L. lactis, which could facilitate the downstream processing and recovery of this industrially important protein. PMID:25482140

  1. 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 ...

  2. Expression of plant flavour genes in Lactococcus lactis

    NARCIS (Netherlands)

    Hernández, I.; Molenaar, D.; Beekwilder, M.J.; Bouwmeester, H.J.; Hylckama Vlieg, van J.E.T.

    2007-01-01

    Lactic acid bacteria, such as Lactococcus lactis, are attractive hosts for the production of plant-bioactive compounds because of their food grade status, efficient expression, and metabolic engineering tools. Two genes from strawberry (Fragaria x ananassa), encoding an alcohol acyltransferase

  3. 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...

  4. 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.

  5. 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 ...

  6. 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

  7. Inhibition ability of probiotic, Lactococcus lactis , against A ...

    African Journals Online (AJOL)

    The present study was designed to investigate the inhibition ability of probiotic, Lactococcus lactis RQ516, against A. hydrophila in vitro and its immunostimulatory effect in tilapia, Oreochromis niloticus as growth promoter. Six tanks were used (T-1 and control treated with and without RQ516, respectively) and three ...

  8. Impact of osmotic stress on protein diffusion in Lactococcus lactis

    NARCIS (Netherlands)

    Mika, Jacek; Schavemaker, Paul; Krasnikov, Viktor; Poolman, Bert

    2014-01-01

    We measured translational diffusion of proteins in the cytoplasm and plasma membrane of the Gram-positive bacterium Lactococcus lactis and probed the effect of osmotic upshift. For cells in standard growth medium the diffusion coefficients for cytosolic proteins (27 and 582 kDa) and 12-transmembrane

  9. Antibacterial Activity of Lactic Acid Bacteria Isolated from Healthy ...

    African Journals Online (AJOL)

    Lactic acid bacteria (LAB), namely, Lactobacillus acidophilus 1, Lactobacillus acidophilus 2, Lactobacillus brevis 1, Lactobacillus rhamnosus 1, Lactococcus lactis subsp. lactis 1, Lactococcus lactis subsp. lactis 2, Lactococcus raffinolactis 1, Pediococcus acidilactici 1, Pediococcus pentosaceus 1, and Pediococcus ...

  10. ORF Alignment: NC_002662 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available eptidase [Lactococcus lactis subsp. lactis Il1403] ... gb|AAK04710.1| mathionine aminopeptidase [Lact...ococcus ... lactis subsp. lactis Il1403] pir||D86701 mathionine ... aminopeptidase [imported

  11. Respon Fagositosis Leukosit Polimorf Babi (in vitro Terhadap Streptoccocus equi Subsp. Zooepidemicus (PHAGOCYTIC RESPONSE OF SWINE POLYMORPH LEUCOCYTES (IN VITRO TO STREPTOCCOCUS EQUI SUBSP. ZOOEPIDEMICUS

    Directory of Open Access Journals (Sweden)

    Iwan Harjono Utama

    2016-08-01

    Full Text Available Respon Fagositosis Leukosit Polimorf Babi (in vitro Terhadap Streptoccocus equi Subsp. Zooepidemicus (PHAGOCYTIC RESPONSE OF SWINE POLYMORPH LEUCOCYTES (IN VITRO TO STREPTOCCOCUS EQUI SUBSP. ZOOEPIDEMICUS

  12. Growth potential of Eucalyptus globulus subsp. bicostata ...

    African Journals Online (AJOL)

    With forestry expanding into mid-altitude drier and warmer, or drier and colder, sites the search to identify reasonably well-performing species/provenances for such ... susceptible than other provenances and controls, also outperformed other E. globulus subsp. bicostata provenances for dbh, height, basal area and volume.

  13. Rapid detection of Mycobacterium avium subsp. paratuberculosis ...

    African Journals Online (AJOL)

    Therefore, alternative diagnostic tests such as PCR, are needed for quick detection of infected animals. In this study, the conventional enrichment and isolation procedure and two IS900-based PCR methods for detection of Mycobactrium avium subsp. paratuberculosis in clinical samples from zoo animals and cattle were ...

  14. Taxonomy of the Anginosus group of the genus Streptococcus and description of Streptococcus anginosus subsp. whileyi subsp. nov. and Streptococcus constellatus subsp. viborgensis subsp. nov.

    Science.gov (United States)

    Jensen, Anders; Hoshino, Tomonori; Kilian, Mogens

    2013-07-01

    The Anginosus group of the genus Streptococcus has been the subject of much taxonomic confusion, which has hampered the full appreciation of its clinical significance. The purpose of this study was to critically re-examine the taxonomy of the Anginosus group, with special attention to β-haemolytic, Lancefield group C strains, using multilocus sequence analysis (MLSA) combined with 16S rRNA gene sequence and phenotypic analyses. Phylogenetic analysis of concatenated sequences of seven housekeeping genes previously used for examination of viridans streptococci distinguished seven distinct and coherent clusters in the Anginosus group. Analyses of 16S rRNA gene sequences and phenotypic characters supported the MLSA clustering and currently recognized taxa of the Anginosus group. Single gene analyses showed considerable allele sharing between species, thereby invalidating identification based on single-locus sequencing. Two novel clusters of β-haemolytic, Lancefield group C strains within the Streptococcus constellatus and Streptococcus anginosus species and isolated from patients with sore throat showed sufficient phylogenetic distances from other clusters to warrant status as novel subspecies. The novel cluster within S. anginosus was identified as the previously recognized DNA homology cluster, DNA group 2. The names S. anginosus subsp. whileyi subsp. nov. (type strain CCUG 39159(T) = DSM 25818(T) = SK1267(T)) and S. constellatus subsp. viborgensis subsp. nov. (type strain SK1359(T) = CCUG 62387(T) = DSM 25819(T)) are proposed.

  15. ORF Alignment: NC_002662 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available lactis subsp. lactis Il1403] ... Length = 134 ... Query: 6 ... LDNLYRAVILDHSSNPRHAGELQTGCMVDLNNPTCGDVIRLT...VEFENDVISNIAFSGHGC 65 ... LDNLYRAVILDHSSNPRHAGELQTGCMVDLNNPTCGDVIRLTVEFENDVISNIAFSGHGC Sbjct: 1 ... LDNLYRAVILDHSSNP

  16. Putrescine biosynthesis in Lactococcus lactis is transcriptionally activated at acidic pH and counteracts acidification of the cytosol.

    Science.gov (United States)

    Del Rio, Beatriz; Linares, Daniel; Ladero, Victor; Redruello, Begoña; Fernandez, Maria; Martin, Maria Cruz; Alvarez, Miguel A

    2016-11-07

    Lactococcus lactis subsp. cremoris CECT 8666 is a lactic acid bacterium that synthesizes the biogenic amine putrescine from agmatine via the agmatine deiminase (AGDI) pathway. The AGDI genes cluster includes aguR. This encodes a transmembrane protein that functions as a one-component signal transduction system, the job of which is to sense the agmatine concentration of the medium and accordingly regulate the transcription of the catabolic operon aguBDAC. The latter encodes the proteins necessary for agmatine uptake and its conversion into putrescine. This work reports the effect of extracellular pH on putrescine biosynthesis and on the genetic regulation of the AGDI pathway. Increased putrescine biosynthesis was detected at acidic pH (pH5) compared to neutral pH. Acidic pH induced the transcription of the catabolic operon via the activation of the aguBDAC promoter PaguB. However, the external pH had no significant effect on the activity of the aguR promoter PaguR, or on the transcription of the aguR gene. The transcriptional activation of the AGDI pathway was also found to require a lower agmatine concentration at pH5 than at neutral pH. Finally, the following of the AGDI pathway counteracted the acidification of the cytoplasm under acidic external conditions, suggesting it to provide protection against acid stress. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. 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.

  18. 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

  19. 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

  20. Identification of Lactobacillus curvatus TMW 1.624 dextransucrase and comparative characterization with Lactobacillus reuteri TMW 1.106 and Lactobacillus animalis TMW 1.971 dextransucrases.

    Science.gov (United States)

    Rühmkorf, Christine; Bork, Christian; Mischnick, Petra; Rübsam, Heinrich; Becker, Thomas; Vogel, Rudi F

    2013-05-01

    Recently, it was affirmed that the exopolysaccharides (EPSs) of Lactobacillus curvatus TMW 1.624, Lactobacillus reuteri TMW 1.106 and Lactobacillus animalis TMW 1.971 improve the quality of gluten-free breads and that they can be produced in situ to levels enabling baking applications. In this study we provide insight into the molecular and biochemical background of EPS production of these three strains. EPS formation strongly correlated with growth and took place during the exponential phase. Gtf genes were heterologously expressed, purified and their enzymatic properties as well as the structures of the EPSs formed were compared. Structural comparison of EPS formed by heterologously expressed glucosyltransferases (Gtfs) and of those formed by the wildtype lactobacilli confirmed that the respective genes/enzymes were identified and examined. The glucan formed by L. animalis Gtf was identified as a linear low molecular weight dextran. Optimal enzymatic conditions were pH 4.4 and 45 °C for the L. reuteri Gtf and pH 4.4 and 31 °C for L. curvatus Gtf. The Gtf from L. animalis had an optimal pH of 5.8 and displayed more than 50% of activity over a broad temperature profile (22-59 °C). The three Gtfs were stimulated by various mono- and divalent metal ions, dextran, as well as levan to different extents. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. The first closed genome sequence of Campylobacter fetus subsp. venerealis biovar intermedius

    Science.gov (United States)

    Campylobacter fetus venerealis biovar intermedius is a variant of Campylobacter fetus subsp. venerealis, the causative agent of Bovine Genital Campylobacteriosis. In contrast to Campylobacter fetus subsp. venerealis which is restricted to the genital tract of cattle, Campylobacter fetus subsp. vener...

  2. Biocontrol of Pectobacterium carotovorum subsp. carotovorum using bacteriophage PP1.

    Science.gov (United States)

    Lim, Jeong-A; Jee, Samnyu; Lee, Dong Hwan; Roh, Eunjung; Jung, Kyusuk; Oh, Changsik; Heu, Sunggi

    2013-08-01

    Pectobacterium carotovorum subsp. carotovorum (formerly Erwinia carotovora subsp. carotovora) is a plant pathogen that causes soft rot and stem rot diseases in several crops, including Chinese cabbage, potato, and tomato. To control this bacterium, we isolated a bacteriophage, PP1, with lytic activity against P. carotovorum subsp. carotovorum. Transmission electron microscopy revealed that the PP1 phage belongs to the Podoviridae family of the order Caudovirales, which exhibit icosahedral heads and short non-contractile tails. PP1 phage showed high specificity for P. carotovorum subsp. carotovorum, and several bacteria belonging to different species and phyla were resistant to PP1. This phage showed rapid and strong lytic activity against its host bacteria in liquid medium and was stable over a broad range of pH values. Disease caused by P. carotovorum subsp. carotovorum was significantly reduced by PP1 treatment. Overall, PP1 bacteriophage effectively controls P. carotovorum subsp. carotovorum.

  3. Staphylococcus petrasii subsp. pragensis subsp. nov., occurring in human clinical material.

    Science.gov (United States)

    Švec, Pavel; De Bel, Annelies; Sedláček, Ivo; Petráš, Petr; Gelbíčová, Tereza; Černohlávková, Jitka; Mašlanˇová, Ivana; Cnockaert, Margo; Varbanovová, Ivana; Echahidi, Fedoua; Vandamme, Peter; Pantuček, Roman

    2015-07-01

    Seven coagulase-negative, oxidase-negative and novobiocin-susceptible staphylococci assigned tentatively as Staphylococcus petrasii were investigated in this study in order to elucidate their taxonomic position. All strains were initially shown to form a genetically homogeneous group separated from remaining species of the genus Staphylococcus by using a repetitive sequence-based PCR fingerprinting with the (GTG)5 primer. Phylogenetic analysis based on 16S rRNA gene, hsp60, rpoB, dnaJ, gap and tuf sequences showed that the group is closely related to Staphylococcus petrasii but separated from the three hitherto known subspecies, S. petrasii subsp. petrasii, S. petrasii subsp. croceilyticus and S. petrasii subsp. jettensis. Further investigation using automated ribotyping, MALDI-TOF mass spectrometry, fatty acid methyl ester analysis, DNA-DNA hybridization and extensive biotyping confirmed that the analysed group represents a novel subspecies within S. petrasii, for which the name Staphylococcus petrasii subsp. pragensis subsp. nov. is proposed. The type strain is NRL/St 12/356(T) ( = CCM 8529(T) = LMG 28327(T)).

  4. 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...... industrial production by employing flow cytometry for viability assessment, cell size comparison, intracellular pH (pHi) determination and cell sorting. The physiological studies of L. lactis were complemented by examining the growth behavior, glucose consumption, lactate production, culturability on solid...

  5. Transforming Lactococcus lactis into a microbial cell factory

    DEFF Research Database (Denmark)

    Petersen, Kia Vest

    Biological conversion of lignocellulosic biomass to biofuels and -chemicals is a promising technology to reduce dependency on fossil fuels. This is important considering the environmental problems associated with consumption of the fossil fuels together with the fact that the reserves are limited...... and will be depleted if the increasing demand continues. However, one of the main challenges in the biological conversion is the identification of suitable platform organisms that can convert all the sugars present in the lignocellulosic biomass, including xylose. The aim of this PhD project was to investigate...... 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...

  6. 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.

  7. 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.

  8. 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.)

  9. Mobile CRISPR/Cas-mediated bacteriophage resistance in Lactococcus lactis.

    Directory of Open Access Journals (Sweden)

    Anne M Millen

    Full Text Available Lactococcus lactis is a biotechnological workhorse for food fermentations and potentially therapeutic products and is therefore widely consumed by humans. It is predominantly used as a starter microbe for fermented dairy products, and specialized strains have adapted from a plant environment through reductive evolution and horizontal gene transfer as evidenced by the association of adventitious traits with mobile elements. Specifically, L. lactis has armed itself with a myriad of plasmid-encoded bacteriophage defensive systems to protect against viral predation. This known arsenal had not included CRISPR/Cas (clustered regularly interspaced short palindromic repeats/CRISPR-associated proteins, which forms a remarkable microbial immunity system against invading DNA. Although CRISPR/Cas systems are common in the genomes of closely related lactic acid bacteria (LAB, none was identified within the eight published lactococcal genomes. Furthermore, a PCR-based search of the common LAB CRISPR/Cas systems (Types I and II in 383 industrial L. lactis strains proved unsuccessful. Here we describe a novel, Type III, self-transmissible, plasmid-encoded, phage-interfering CRISPR/Cas discovered in L. lactis. The native CRISPR spacers confer resistance based on sequence identity to corresponding lactococcal phage. The interference is directed at phages problematic to the dairy industry, indicative of a responsive system. Moreover, targeting could be modified by engineering the spacer content. The 62.8-kb plasmid was shown to be conjugally transferrable to various strains. Its mobility should facilitate dissemination within microbial communities and provide a readily applicable system to naturally introduce CRISPR/Cas to industrially relevant strains for enhanced phage resistance and prevention against acquisition of undesirable genes.

  10. Transcriptional regulation of the Kluyveromyces lactis beta-galactosidase gene.

    OpenAIRE

    Lacy, L R; Dickson, R C

    1981-01-01

    We examined the molecular basis for beta-D-galactosidase (EC 3.2.1.23) induction in the yeast Kluyveromyces lactis. The protein synthesis inhibitor anisomycin effectively blocked both protein synthesis and enzyme induction by lactose. Further, hybridization analysis with the cloned beta-galactosidase gene indicated coordinate increases in the concentration of beta-galactosidase messenger ribonucleic acid and enzyme activity. The half-life of beta-galactosidase messenger ribonucleic acid was t...

  11. Iridoid Glucosides from Lamium garganicum subsp. laevigatum

    DEFF Research Database (Denmark)

    Tayfun, Ersöz; Kaya, Duygu; Yalcin, Funda Nuray

    2007-01-01

    Phytochemical investigations on the above ground parts of Lamium garganicum subsp. laevigatum resulted in the isolation of seven iridoid glucosides, shanzhiside methyl ester (1), barlerin (8-O-acetylshanzhiside methyl ester; 2), 6-O-syringyl-8-O-acetylshanzhiside methyl ester (3), 6β-hydroxyipola......Phytochemical investigations on the above ground parts of Lamium garganicum subsp. laevigatum resulted in the isolation of seven iridoid glucosides, shanzhiside methyl ester (1), barlerin (8-O-acetylshanzhiside methyl ester; 2), 6-O-syringyl-8-O-acetylshanzhiside methyl ester (3), 6β......-hydroxyipolamiide (4), lamalbide (5), dehydropenstemoside (6), and sesamoside (7). The structure of the iridoids was elucidated by spectroscopic (UV, IR, 1D- and 2D-NMR, and ESI-MS) evidence....

  12. 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...

  13. 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.

  14. Campylobacter pinnipediorum sp. nov., isolated from pinnipeds, comprising Campylobacter pinnipediorum subsp. pinnipediorum subsp. nov. and Campylobacter pinnipediorum subsp. caledonicus subsp. nov.

    Science.gov (United States)

    Gilbert, Maarten J; Miller, William G; Leger, Judy St; Chapman, Mary H; Timmerman, Arjen J; Duim, Birgitta; Foster, Geoffrey; Wagenaar, Jaap A

    2017-06-01

    During independent diagnostic screenings of otariid seals in California (USA) and phocid seals in Scotland (UK), Campylobacter-like isolates, which differed from the established taxa of the genus Campylobacter, were cultured from abscesses and internal organs of different seal species. A polyphasic study was undertaken to determine the taxonomic position of these six isolates. The isolates were characterized by 16S rRNA gene and AtpA sequence analysis and by conventional phenotypic testing. The whole-genome sequences were determined for all isolates, and the average nucleotide identity (ANI) was determined. The isolates formed a separate phylogenetic clade, divergent from all other taxa of the genus Campylobacter and most closely related to Campylobactermucosalis. Although all isolates showed 100 % 16S rRNA gene sequence homology, AtpA and ANI analyses indicated divergence between the otariid isolates from California and the phocid isolates from Scotland, which warrants subspecies status for each clade. The two subspecies could also be distinguished phenotypically on the basis of catalase activity. This study shows clearly that the isolates obtained from pinnipeds represent a novel species within the genus Campylobacter, for which the name Campylobacter pinnipediorum sp. nov. is proposed. Within this novel species, the Californian isolates represent a separate subspecies, for which the name C. pinnipediorum subsp. pinnipediorum subsp. nov. is proposed. The type strain for both this novel species and subspecies is RM17260T (=LMG 29472T=CCUG 69570T). The Scottish isolates represent another subspecies, for which the name C. pinnipediorum subsp. caledonicus subsp. nov. is proposed. The type strain of this subspecies is M302/10/6T (=LMG 29473T=CCUG 68650T).

  15. Fragrance components of Platanthera bifolia subsp. osca.

    Science.gov (United States)

    D'Auria, Maurizio; Lorenz, Richard; Racioppi, Rocco; Romano, Vito Antonio

    2017-07-01

    SPME-GC-MS analysis of the scent of Platanthera bifolia subsp. osca collected during the night showed as main components lilac alcohols B, C and D and lilac aldehydes A, B and C. Other significant chemical components were linalool and caryophyllene. Some differences were found in comparison with previously reported analyses of the scent of P. bifolia and Platanthera chlorantha. The most important difference found was in the composition of the ester fraction.

  16. Bacteriological and Molecular Detection of Streptococcus equi subsp. equi and Streptococcus equi subsp. zooepidemicus in Equines of Northern India.

    Science.gov (United States)

    Mir, Irfan Ahmad; Kumar, Bablu; Taku, Anil; Faridi, Farah; Bhat, Mohd Altaf; Baba, Naseer Ahmad; Maqbool, Tahir

    2013-01-01

    Present study was undertaken to study the prevalence of β-haemolytic streptococci in equine of northern temperate region of Jammu and Kashmir, India. One hundred and forty one samples were collected in duplicate from nasopharyngeal tract of diseased (53) and apparently healthy equine (88) for isolation and direct PCR. A total of 77 isolates of streptococci were recovered from 141 samples with an overall prevalence rate of 54.60%. Out of these 77 isolates, 52 were from diseased and 25 from apparently healthy animals. Of the 77 isolates, 4 were identified as Streptococcus equi subsp. equi, 56 as S. equi subsp. zooepidemicus and 17 as S. dysgalactiae subsp. equisimilis. Thus the overall prevalence of S. equi subsp. equi, S. equi subsp. zooepidemicus and S. dysgalactiae subsp. equisimilis was 2.83, 39.71 and 12.05% respectively. The sensitivity of the PCR for the detection of S. equi species was found higher when attempted from direct swab samples.

  17. Isolation and Characterisation of Bacteriocin and Aggregation-Promoting Factor Production in Lactococcus lactis ssp. lactis BGBM50 Strain

    Directory of Open Access Journals (Sweden)

    Nemanja Mirkovic

    2015-01-01

    Full Text Available Lactococcus lactis ssp. lactis BGBM50, a producer of lactococcin G and aggregation-promoting factor, was isolated from selected lactic acid bacteria taken from semi-hard cheese traditionally produced in the village Žanjic, Montenegro. Strain BGBM50 harbours a number of plasmids of diff erent sizes. Plasmid curing experiments showed that genes for bacteriocin production are located on pBM140, a plasmid 140 kb in length. PCR analysis with primers specifi c for lactococcin Q and G genes gave fragment of the expected size. In addition, after plasmid curing of strain BGBM50, different derivatives with altered phenotypes were obtained, among them BGBM50-34 strain, which retained bacteriocin synthesis but had enhanced aggregation ability.

  18. 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.

  19. Shortening of the Lactobacillus paracasei subsp. paracasei BGNJ1-64 AggLb protein switches its activity from auto-aggregation to biofilm formation

    Directory of Open Access Journals (Sweden)

    Marija Miljković

    2016-09-01

    Full Text Available AggLb is the largest (318.6 kDa aggregation-promoting protein of Lactobacillus paracasei subsp. paracasei BGNJ1-64 responsible for forming large cell aggregates, which causes auto-aggregation, collagen binding and pathogen exclusion in vitro. It contains an N-terminus leader peptide, followed by six successive collagen binding domains, 20 successive repeats (CnaB-like domains and an LPXTG sorting signal at the C-terminus for cell wall anchoring. Experimental information about the roles of the domains of AggLb is currently unknown. To define the domain that confers cell aggregation and the key domains for interactions of specific affinity between AggLb and components of the extracellular matrix (ECM, we constructed a series of variants of the aggLb gene and expressed them in Lactococcus lactis subsp. lactis BGKP1-20 using a lactococcal promoter. All of the variants contained a leader peptide, an inter collagen binding-CnaB domain region (used to raise an anti-AggLb antibody, an anchor domain and a different number of collagen binding and CnaB-like domains. The role of the collagen binding repeats of the N-terminus in auto-aggregation and binding to collagen and fibronectin was confirmed. Deletion of the collagen binding repeats II, III and IV resulted in a loss of the strong auto-aggregation, collagen and fibronectin binding abilities whereas the biofilm formation capability was increased. The strong auto-aggregation, collagen and fibronectin binding abilities of AggLb were negatively correlated to biofilm formation.

  20. Genotype-phenotype matching analysis of 38 Lactococcus lactis strains using random forest methods

    NARCIS (Netherlands)

    Bayjanov, J.; Starrenburg, M.J.; Sijde, M.R. van der; Siezen, R.J.; Hijum, S.A.F.T. van

    2013-01-01

    BACKGROUND: Lactococcus lactis is used in dairy food fermentation and for the efficient production of industrially relevant enzymes. The genome content and different phenotypes have been determined for multiple L. lactis strains in order to understand intra-species genotype and phenotype diversity

  1. Heterologous expression and characterization of recombinant Lactococcus lactis neutral endopeptidase (Neprilysin)

    NARCIS (Netherlands)

    Lian, W; Wu, D; Konings, W.N; Mierau, I; Hersh, L.B

    1996-01-01

    A neutral endopeptidase (NEP) from Lactococcus lactis has recently been cloned and shown to contain high sequence homology with the human neutral endopeptidase, endopeptidase 24.11 (I. Mierau et al., J. Bacteriol. 175, 2087-2096, 1993). The gene for the neutral endopeptidase from L. lactis was

  2. Regulation of the Glutamate-Glutamine Transport System by Intracellular pH in Streptococcus lactis

    NARCIS (Netherlands)

    POOLMAN, B; HELLINGWERF, KJ; KONINGS, WN

    Various methods of manipulation of the intracellular pH in Streptococcus lactis result in a unique relationship between the rate of glutamate and glutamine transport and the cytoplasmic pH. The initial rate of glutamate uptake by S. lactis cells increases more than 30-fold when the intracellular pH

  3. 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,

  4. Regulation of Arginine-Ornithine Exchange and the Arginine Deiminase Pathway in Streptococcus lactis

    NARCIS (Netherlands)

    POOLMAN, B; DRIESSEN, AJM; KONINGS, WN

    1987-01-01

    Streptococcus lactis metabolizes arginine by the argiqine deiminase (ADI) pathway. Resting cells of S. lactis grown in the presence of galactose and arginine maintain a high intracellular ornithine pool in the absence of arginine and other exogenous energy sources. Addition of arginine results in a

  5. 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

  6. 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...

  7. Time-resolved genetic responses of Lactococcus lactis to a dairy environment

    NARCIS (Netherlands)

    Bachmann, H.; Wilt, de L.; Kleerebezem, M.; Hylckama Vlieg, van J.E.T.

    2010-01-01

    Lactococcus lactis is one of main bacterial species found in mixed dairy starter cultures for the production of semi-hard cheese. Despite the appreciation that mixed cultures are essential for the eventual properties of the manufactured cheese the vast majority of studies on L. lactis were carried

  8. 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.

  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. Epipactis helleborine (L. Crantz subsp. moratoria A. Riechelmann

    Directory of Open Access Journals (Sweden)

    Lipovšek Matej

    2017-06-01

    Full Text Available The group of Epipactis helleborine s.l. includes several subspecies. A new subspecies Epipactis helleborine subsp. moratoria was determined in Slovenia in 2015. It thrives in mixed wood in a region of Gorica at Raztez. Morphologic and phenomenological comparison confirmed clear differences between E. helleborine subsp. moratoria and E. helleborine subsp. helleborine. The characteristic differences seen in E. helleborine subsp. moratoria are the stem which is more or less bent at the level of the leaf base, the plants are smaller and more slender than E. helleborine, there are also differences in the flowers and the leaves. The ovary in E. moratoria is often in a horizontal position, especially at the time of fruiting, wheras in E. helleborine ovary usually hangs down. All of the wild orchids in Slovenia are protected species and among them it is Epipactis helleborine subsp. moratoria which, up till now is only known at one site.

  11. Influence of extracellular pH on growth, viability, cell size, acidification activity, and intracellular pH of Lactococcus lactis in batch fermentations.

    Science.gov (United States)

    Hansen, Gunda; Johansen, Claus Lindvald; Marten, Gunvor; Wilmes, Jacqueline; Jespersen, Lene; Arneborg, Nils

    2016-07-01

    In this study, we investigated the influence of three extracellular pH (pHex) values (i.e., 5.5, 6.5, and 7.5) on the growth, viability, cell size, acidification activity in milk, and intracellular pH (pHi) of Lactococcus lactis subsp. lactis DGCC1212 during pH-controlled batch fermentations. A universal parameter (e.g., linked to pHi) for the description or prediction of viability, specific acidification activity, or growth behavior at a given pHex was not identified. We found viability as determined by flow cytometry to remain high during all growth phases and irrespectively of the pH set point. Furthermore, regardless of the pHex, the acidification activity per cell decreased over time which seemed to be linked to cell shrinkage. Flow cytometric pHi determination demonstrated an increase of the averaged pHi level for higher pH set points, while the pH gradient (pHi-pHex) and the extent of pHi heterogeneity decreased. Cells maintained positive pH gradients at a low pHex of 5.5 and even during substrate limitation at the more widely used pHex 6.5. Moreover, the strain proved able to grow despite small negative or even absent pH gradients at a high pHex of 7.5. The larger pHi heterogeneity at pHex 5.5 and 6.5 was associated with more stressful conditions resulting, e.g., from higher concentrations of non-dissociated lactic acid, while the low pHi heterogeneity at pHex 7.5 most probably corresponded to lower concentrations of non-dissociated lactic acid which facilitated the cells to reach the highest maximum active cell counts of the three pH set points.

  12. Contribution of plasmid-encoded peptidase S8 (PrtP) to adhesion and transit in the gut of Lactococcus lactis IBB477 strain.

    Science.gov (United States)

    Radziwill-Bienkowska, Joanna Maria; Robert, Véronique; Drabot, Karolina; Chain, Florian; Cherbuy, Claire; Langella, Philippe; Thomas, Muriel; Bardowski, Jacek Karol; Mercier-Bonin, Muriel; Kowalczyk, Magdalena

    2017-07-01

    The ability of Lactococcus lactis to adhere to the intestinal mucosa can potentially prolong the contact with the host, and therefore favour its persistence in the gut. In the present study, the contribution of plasmid-encoded factors to the adhesive and transit properties of the L. lactis subsp. cremoris IBB477 strain was investigated. Plasmid-cured derivatives as well as deletion mutants were obtained and analysed. Adhesion tests were performed using non-coated polystyrene plates, plates coated with mucin or fibronectin and mucus-secreting HT29-MTX intestinal epithelial cells. The results indicate that two plasmids, pIBB477a and b, are involved in adhesion of the IBB477 strain. One of the genes localised on plasmid pIBB477b (AJ89_14230), which encodes cell wall-associated peptidase S8 (PrtP), mediates adhesion of the IBB477 strain to bare, mucin- and fibronectin-coated polystyrene, as well as to HT29-MTX cells. Interactions between bacteria and mucus secreted by HT29-MTX cells were further investigated by fluorescent staining and confocal microscopy. Confocal images showed that IBB477 forms dense clusters embedded in secreted mucus. Finally, the ability of IBB477 strain and its ΔprtP deletion mutant to colonise the gastrointestinal tract of conventional C57Bl/6 mice was determined. Both strains were present in the gut for up to 72 h. In summary, adhesion and persistence of IBB477 were analysed by in vitro and in vivo approaches, respectively. Our studies revealed that plasmidic genes encoding cell surface proteins are more involved in the adhesion of IBB477 strain than in the ability to confer a selective advantage in the gut.

  13. Update on Streptococcus equi subsp equi infections.

    Science.gov (United States)

    Mallicote, Martha

    2015-04-01

    There are few diseases that ignite as much fervor among horse owners as strangles. Streptococcus equi subsp equi (strangles) infections frequently require the treating veterinarian to manage not only the clinical cases but also the biosecurity and provision of information to all involved parties. Although the disease is typically characterized by low mortality and high morbidity, restrictions of horse movement that result from appropriate quarantine procedures often frustrate the involved parties. The aims of this article are to provide clinically relevant information for diagnosis, treatment, and biosecurity management of strangles infection. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Utilization of (15)N-labelled yeast hydrolysate in Lactococcus lactis IL1403 culture indicates co-consumption of peptide-bound and free amino acids with simultaneous efflux of free amino acids.

    Science.gov (United States)

    Kevvai, Kaspar; Kütt, Mary-Liis; Nisamedtinov, Ildar; Paalme, Toomas

    2014-03-01

    Lactococcus lactis subsp. lactis IL1403 was grown in medium containing unlabelled free amino acids and (15)N-labelled yeast hydrolysate to gain insight into the role of peptides as a source of amino acids under conditions where free amino acids are abundant. A mathematical model was composed to estimate the fluxes of free and peptide-derived amino acids into and out of the intracellular amino acid pool. We observed co-consumption of peptides and free amino acids and a considerable efflux of most free amino acids during growth. We did not observe significant differences between the peptide consumption patterns of essential and non-essential amino acids, which suggests that the incorporation of a particular amino acid is more dependent on its availability in a readily assimilated form than the organism's auxotrophy for it. For most amino acids the contribution of peptide-bound forms to the formation of biomass was initially between 30 and 60 % with the remainder originating from free amino acids. During the later stages of fermentation we observed a decrease in the utilization of peptide-bound amino acids, thus indicating that the more readily assimilated peptides are gradually exhausted from the medium during growth.

  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. 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.

  17. 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.

  18. The effect of yoghurt and its probiotics on blood pressure and serum lipid profile; a randomised controlled trial.

    Science.gov (United States)

    Ivey, K L; Hodgson, J M; Kerr, D A; Thompson, P L; Stojceski, B; Prince, R L

    2015-01-01

    Despite strong mechanistic data, and promising results from in vitro and animal studies, the ability of probiotic bacteria to improve blood pressure and serum lipid concentrations in humans remains uncertain. The aim of this study was to determine the effect of Lactobacillus acidophilus La5 and Bifidobacterium animalis subsp lactis Bb12, provided in either yoghurt or capsule form, on home blood pressure and serum lipid profile. Following a 3-week washout period, 156 overweight men and women over 55 y were randomized to a 6-week double-blinded, factorial, parallel study. The four intervention groups were: A) probiotic yoghurt plus probiotic capsules; B) probiotic yoghurt plus placebo capsules; C) control milk plus probiotic capsules; and D) control milk plus placebo capsules. Each probiotic test article provided a minimum L. acidophilus La5 and B. animalis subsp. lactis Bb12 dose of 3.0 × 10⁹ CFU/d. Home blood pressure monitoring, consisting of 7-day bi-daily repeat measurements, were collected at baseline and week 6. Fasting total cholesterol, low density lipoprotein cholesterol (LDLC), high density lipoprotein cholesterol (HDLC), and serum triglyceride were performed at baseline and week 6. When compared to control milk, probiotic yoghurt did not significantly alter blood pressure, heart rate or serum lipid concentrations (P > 0.05). Similarly, when compared to placebo capsules, supplementation with probiotic capsules did not alter blood pressure or concentrations of total cholesterol LDLC, HDLC, or triglycerides (P > 0.05). The probiotic strains L. acidophilus La5 and B. animalis subsp. lactis Bb12 did not improve cardiovascular risk factors. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. The influence of the different initial probiotic bacteria concentration on sweet whey fermentation

    Directory of Open Access Journals (Sweden)

    Bojan Matijević

    2008-12-01

    Full Text Available Whey is nutritiously very high-quality secondary product from cheese making which is not used enough in human diet. When the fermentation is performed with probiotic bacteria it additionally increases its nutritional and health values. This research examines the influence of different amount of inoculum addition (2.5, 5 and 7.5 % of monoculture Lactobacillus acidophilus La-5 or Bifidobacterium animalis subsp. lactis BB-12, on the course of fermentation of reconstitued sweet whey at 37 °C. During fermentation and 28 days of cool storage fermented whey pH value, titratable acidity and the viable cells count was monitored. Fermentation with 7.5 % inoculum of monoculture Lactobacillus acidophilus La-5 lasted the shortest (about 13.3 hours, while the fermentation with 2.5 % inoculum lasted the longest (about 15.5 hours. The viable cells count of Lactobacillus acidophilus La-5 cells in all whey samples has increased during fermentation for about 1.3 log CFU/mL and at the end of fermentation was about 8.5 log CFU/mL. Whey fermentation with 7.5 % added inoculum of monoculture Bifidobacterium animalis subsp. lactis BB-12 showed no difference in duration time in comparison to whey fermentation with 2.5 % inoculum addition. The viable cells count of Bifidobacterium animalis subsp. lactis BB-12 has increased during fermentation for about 0.9 log CFU/mL and at the end of fermentation was about 8.7 log CFU/mL. The amount of inoculum had no influence on survival of probiotic bacteria in fermented whey regardless of monoculture used.

  20. Assessment of probiotic viability during Cheddar cheese manufacture and ripening using propidium monoazide-PCR quantification

    Directory of Open Access Journals (Sweden)

    Emilie eDesfossés-Foucault

    2012-10-01

    Full Text Available The use of a suitable food carrier such as cheese could significantly enhance probiotic viability during storage. The main goal of this study was to assess viability of commercial probiotic strains during Cheddar cheesemaking and ripening (four to six months by comparing the efficiency of microbiological and molecular approaches. Molecular methods such as quantitative PCR (qPCR allow bacterial quantification, and DNA-blocking molecules such as propidium monoazide (PMA select only the living cells’ DNA. Cheese samples were manufactured with a lactococci starter and with one of three probiotic strains (Bifidobacterium animalis subsp. lactis BB-12, Lactobacillus rhamnosus RO011 or Lactobacillus helveticus RO052 or a mixed culture containing B. animalis subsp. lactis BB-12 and L. helveticus RO052 (MC1, both lactobacilli strains (MC2 or all three strains (MC3. DNA extractions were then carried out on PMA-treated and non-treated cell pellets in order to assess PMA treatment efficiency, followed by quantification using the 16S rRNA gene, the elongation factor Tu gene (tuf or the transaldolase gene (tal. Results with intact/dead ratios of bacteria showed that PMA-treated cheese samples had a significantly lower bacterial count than non-treated DNA samples (P<0.005, confirming that PMA did eliminate dead bacteria from PCR quantification. For both quantification methods, the addition of probiotic strains seemed to accelerate the loss of lactococci viability in comparison to control cheese samples, especially when L. helveticus RO052 was added. Viability of all three probiotic strains was also significantly reduced in mixed culture cheese samples (P<0.0001, B. animalis subsp. lactis BB-12 being the most sensitive to the presence of other strains. However, all probiotic strains did retain their viability (log nine cfu/g of cheese throughout ripening. This study was successful in monitoring living probiotic species in Cheddar cheese samples through PMA-qPCR.

  1. Genome sequencing identifies Listeria fleischmannii subsp. coloradonensis subsp. nov., isolated from a ranch.

    Science.gov (United States)

    den Bakker, Henk C; Manuel, Clyde S; Fortes, Esther D; Wiedmann, Martin; Nightingale, Kendra K

    2013-09-01

    Twenty Listeria-like isolates were obtained from environmental samples collected on a cattle ranch in northern Colorado; all of these isolates were found to share an identical partial sigB sequence, suggesting close relatedness. The isolates were similar to members of the genus Listeria in that they were Gram-stain-positive, short rods, oxidase-negative and catalase-positive; the isolates were similar to Listeria fleischmannii because they were non-motile at 25 °C. 16S rRNA gene sequencing for representative isolates and whole genome sequencing for one isolate was performed. The genome of the type strain of Listeria fleischmannii (strain LU2006-1(T)) was also sequenced. The draft genomes were very similar in size and the average MUMmer nucleotide identity across 91% of the genomes was 95.16%. Genome sequence data were used to design primers for a six-gene multi-locus sequence analysis (MLSA) scheme. Phylogenies based on (i) the near-complete 16S rRNA gene, (ii) 31 core genes and (iii) six housekeeping genes illustrated the close relationship of these Listeria-like isolates to Listeria fleischmannii LU2006-1(T). Sufficient genetic divergence of the Listeria-like isolates from the type strain of Listeria fleischmannii and differing phenotypic characteristics warrant these isolates to be classified as members of a distinct infraspecific taxon, for which the name Listeria fleischmannii subsp. coloradonensis subsp. nov. is proposed. The type strain is TTU M1-001(T) ( =BAA-2414(T) =DSM 25391(T)). The isolates of Listeria fleischmannii subsp. coloradonensis subsp. nov. differ from the nominate subspecies by the inability to utilize melezitose, turanose and sucrose, and the ability to utilize inositol. The results also demonstrate the utility of whole genome sequencing to facilitate identification of novel taxa within a well-described genus. The genomes of both subspecies of Listeria fleischmannii contained putative enhancin genes; the Listeria fleischmannii subsp

  2. Supplementation with fruit and okara soybean by-products and amaranth flour increases the folate production by starter and probiotic cultures.

    Science.gov (United States)

    Albuquerque, Marcela Albuquerque Cavalcanti de; Bedani, Raquel; Vieira, Antônio Diogo Silva; LeBlanc, Jean Guy; Saad, Susana Marta Isay

    2016-11-07

    The ability of two starter cultures (Streptococcus (S.) thermophilus ST-M6 and St. thermophilus TA-40) and eleven probiotic cultures (St. thermophilus TH-4, Lactobacillus (Lb.) acidophilus LA-5, Lb. fermentum PCC, Lb. reuteri RC-14, Lb. paracasei subsp. paracasei, Lb. casei 431, Lb. paracasei subsp. paracasei F19, Lb. rhamnosus GR-1, and Lb. rhamnosus LGG, Bifidobacterium (B.) animalis subsp. lactis BB-12, B. longum subsp. longum BB-46, and B. longum subsp. infantis BB-02) to produce folate in a modified MRS broth (mMRS) supplemented with different fruit (passion fruit, acerola, orange, and mango) and okara soybean by-products and amaranth flour was investigated. Initially, the folate content of each vegetable substrate was determined: passion fruit by-product showed the lowest folate content (8±2ng/mL) and okara the highest (457±22ng/mL). When the orange by-product and amaranth flour were added to mMRS, all strains were able to increase folate production after 24h of fermentation. B. longum subsp infantis BB-02 produced the highest concentrations (1223±116ng/mL) in amaranth flour. Okara was the substrate that had the lowest impact on the folate production by all strains evaluated. Lb. acidophilus LA-5 (297±36ng/mL) and B. animalis subsp. lactis BB-12 (237±23ng/mL) were also able to produce folate after growth in mMRS containing acerola and orange by-products, respectively. The results of this study demonstrate that folate production is not only strain-dependent but also influenced by the addition of different substrates in the growth media. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Genetic Diversity of Pectobacterium carotovorum subsp. brasiliensis Isolated in Korea

    Directory of Open Access Journals (Sweden)

    Dong Hwan Lee

    2014-06-01

    Full Text Available The plant pathogenic bacterial genus Pectobacteirum consists of heterogeneous strains. The P. carotovorum species is a complex strain showing divergent characteristics, and a new subspecies named P. carotovorum subsp. brasiliensis has been identified recently. In this paper, we re-identified the P. carotovorum subsp. brasiliensis isolates from those classified under the subspecies carotovorum and newly isolated P. carotovorum subsp. brasiliensis strains. All isolates were able to produce plant cell-wall degrading enzymes such as pectate lyase, polygalacturonase, cellulase and protease. We used genetic and biochemical methods to examine the diversity of P. carotovorum subsp. brasiliensis isolates, and found genetic diversity within the brasiliensis subsp. isolates in Korea. The restriction fragment length polymorphism analysis based on the recA gene revealed a unique pattern for the brasiliensis subspecies. The Korean brasiliensis subsp. isolates were divided into four clades based on pulsed-field gel electrophoresis. However, correlations between clades and isolated hosts or year could not be found, suggesting that diverse brasiliensis subsp. isolates existed.

  4. Genetic Diversity of Pectobacterium carotovorum subsp. brasiliensis Isolated in Korea.

    Science.gov (United States)

    Lee, Dong Hwan; Kim, Jin-Beom; Lim, Jeong-A; Han, Sang-Wook; Heu, Sunggi

    2014-06-01

    The plant pathogenic bacterial genus Pectobacteirum consists of heterogeneous strains. The P. carotovorum species is a complex strain showing divergent characteristics, and a new subspecies named P. carotovorum subsp. brasiliensis has been identified recently. In this paper, we re-identified the P. carotovorum subsp. brasiliensis isolates from those classified under the subspecies carotovorum and newly isolated P. carotovorum subsp. brasiliensis strains. All isolates were able to produce plant cell-wall degrading enzymes such as pectate lyase, polygalacturonase, cellulase and protease. We used genetic and biochemical methods to examine the diversity of P. carotovorum subsp. brasiliensis isolates, and found genetic diversity within the brasiliensis subsp. isolates in Korea. The restriction fragment length polymorphism analysis based on the recA gene revealed a unique pattern for the brasiliensis subspecies. The Korean brasiliensis subsp. isolates were divided into four clades based on pulsed-field gel electrophoresis. However, correlations between clades and isolated hosts or year could not be found, suggesting that diverse brasiliensis subsp. isolates existed.

  5. Functional Expression of an Orchid Fragrance Gene in Lactococcus lactis

    Science.gov (United States)

    Song, Adelene Ai Lian; Abdullah, Janna O.; Abdullah, Mohd Puad; Shafee, Norazizah; Rahim, Raha A.

    2012-01-01

    Vanda Mimi Palmer (VMP), an orchid hybrid of Vanda tesselata and Vanda Tan Chay Yan is a highly scented tropical orchid which blooms all year round. Previous studies revealed that VMP produces a variety of isoprenoid volatiles during daylight. Isoprenoids are well known to contribute significantly to the scent of most fragrant plants. They are a large group of secondary metabolites which may possess valuable characteristics such as flavor, fragrance and toxicity and are produced via two pathways, the mevalonate (MVA) pathway or/and the 2-C-methyl-D-erythritol-4-phosphate (MEP) pathway. In this study, a sesquiterpene synthase gene denoted VMPSTS, previously isolated from a floral cDNA library of VMP was cloned and expressed in Lactococcus lactis to characterize the functionality of the protein. L. lactis, a food grade bacterium which utilizes the mevalonate pathway for isoprenoid production was found to be a suitable host for the characterization of plant terpene synthases. Through recombinant expression of VMPSTS, it was revealed that VMPSTS produced multiple sesquiterpenes and germacrene D dominates its profile. PMID:22408409

  6. 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...

  7. 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.

  8. [Resistance of Lactobacillus casei subsp. casei SY13 and Lactobacillus delbrueckii subsp. bulgaricus LJJ to reactive oxygen species].

    Science.gov (United States)

    Zhang, Shuwen; Lv, Jiaping; Menghe, Bilige; Zhang, Heping; Zhang, Liyu; Song, Jinhui; Wang, Zhifei

    2009-02-01

    We evaluated antioxidative effect of two antioxidative strains, isolated from the traditional fermented dairy products. Both intact cells and cell-free extract of Lactobacillus casei subsp. casei SY13 and Lactobacillus delbrueckii subsp. bulgaricus LJJ were used to study the inhibited effect of linoleic acid peroxidation, the ability of scavenging 1,1-diphenyl-2-picrylhydrazyl radical, hydroxyl radical, superoxide anion radical,the ability of tolerancing hydrogen peroxide and the chelating capacity of ferrous ion and reducting activity. Lactobacillus casei subsp. casei SY13 and Lactobacillus delbrueckii subsp. bulgaricus LJJ demonstrated highest inhibition on linoleic acid peroxidation by 62.95% and 66.16%, respectively. The cell-free extract showed excellent scavenging superoxide anion and hydroxyl radicals activity. However, the intact cells of Lactobacillus delbrueckii subsp. bulgaricus LJJ scavenging superoxide and hydroxyl radicals capacity were not detected. The intact cells of Lactobacillus casei subsp. casei SY13 and Lactobacillus delbrueckii subsp. bulgaricus LJJ on 1,1-diphenyl-2-picrylhydrazyl radical scavenging ability and chelating ferrous ion capacity were superior to cell-free extract. The highest reduced activety was equivalent to 305 micromol/L and 294 micromol/L L-cysteine. Two latobacilli strains had good antioxidant capacity. As potential probiotics, it can be used in future.

  9. Molecular characterization of virulence genes of Streptococcus equi subsp. equi and Streptococcus equi subsp. zooepidemicus in equines.

    Science.gov (United States)

    Javed, R; Taku, A K; Gangil, Rakhi; Sharma, R K

    2016-08-01

    The aim was to determine the occurrence of streptococci in equines in Jammu (R. S. Pura, Katra), characterization of Streptococci equi subsp. equi and Streptococcus equi subsp. zooepidemicus with respect to their virulence traits and to determine antibiotic sensitivity pattern of virulent Streptococcus isolates. A total of 96 samples were collected from both clinically affected animals (exhibiting signs of respiratory tract disease) and apparently healthy animals and were sent to laboratory. The organisms were isolated on Columbia nalidixic acid agar containing 5% sheep blood as well as on sheep blood agar and confirmed by cultural characteristics and biochemical tests. Molecular detection of Streptococcus was done directly from cultures using sodA and seM gene-based polymerase chain reaction (PCR). Antibiogram was performed against five antibiotics such as amoxicillin, penicillin G, streptomycin, rifampicin, and methicillin. During this study, a total 40 streptococcal isolates were obtained out of which 2 isolates were of S. equi subsp. equi, 12 isolates were from S. equi subsp. zooepidemicus. In the PCR-based detection, we revealed amplicons of 235 bp and 679 bp for confirmation of sodA and seM gene, respectively. In antibiogram, two isolates of S. equi subsp. equi were found resistant to penicillin G, and all other isolates were found sensitive to amoxicillin and streptomycin. The majority of streptococcal infections was due to S. equi subsp. Zooepidemicus, and thus was recognized as a potential pathogen of diseases of equines besides S. equi subsp. equi.

  10. Raffinose family oligosaccharide utilisation by probiotic bacteria: insight into substrate recognition, molecular architecture and diversity of GH36 alpha-galactosidases

    DEFF Research Database (Denmark)

    Abou Hachem, Maher; Fredslund, Folmer; Andersen, Joakim Mark

    2012-01-01

    The organisation of genes conferring utilisation of raffinose family oligosaccharides (RFOs) has been analysed in several probiotic bacteria from the Bifidobacterium and Lactobacillus genera. Glycoside hydrolase family 36 (GH36) alpha-galatosidase encoding genes occur together with sugar transport....... animalis subsp. lactis Bl-04 was upregulated upon growth on RFO, suggesting that the other two gene products may have different specificities. The structure of the GH36 homotetrameric alpha-galactosidase from L. acidophilus NCFM (LaMel36A) was determined in complex with galactose bound in the active site...

  11. 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.

  12. 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

  13. Surveillance of Mycobacterium avium subsp. paratuberculosis in dairy herds

    NARCIS (Netherlands)

    Weber, M.F.

    2009-01-01

    In this thesis, the potential for improvements in surveillance of Mycobacterium avium subsp. paratuberculosis (Map) infection and paratuberculosis in dairy herds was investigated, leading to a reduction in surveillance costs whilst continuing to meet specific quality targets. In particular,

  14. Knowledge on Sclerocarya birrea subsp. caffra with emphasis on its ...

    African Journals Online (AJOL)

    Knowledge on Sclerocarya birrea subsp. caffra with emphasis on its importance as a non-timber forest product in South and southern Africa: a summary: Part 1: Taxonomy, ecology and role in rural livelihoods: review paper.

  15. Description of Klebsiella quasipneumoniae sp. nov., isolated from human infections, with two subspecies, Klebsiella quasipneumoniae subsp. quasipneumoniae subsp. nov. and Klebsiella quasipneumoniae subsp. similipneumoniae subsp. nov., and demonstration that Klebsiella singaporensis is a junior heterotypic synonym of Klebsiella variicola.

    Science.gov (United States)

    Brisse, Sylvain; Passet, Virginie; Grimont, Patrick A D

    2014-09-01

    Strains previously classified as members of Klebsiella pneumoniae phylogroups KpI, KpII-A, KpII-B and KpIII were characterized by 16S rRNA (rrs) gene sequencing, multilocus sequence analysis based on rpoB, fusA, gapA, gyrA and leuS genes, average nucleotide identity and biochemical characteristics. Phylogenetic analysis demonstrated that KpI and KpIII corresponded to K. pneumoniae and Klebsiella variicola, respectively, whereas KpII-A and KpII-B formed two well-demarcated sequence clusters distinct from other members of the genus Klebsiella. Average nucleotide identity between KpII-A and KpII-B was 96.4 %, whereas values lower than 94 % were obtained for both groups when compared with K. pneumoniae and K. variicola. Biochemical properties differentiated KpII-A, KpII-B, K. pneumoniae and K. variicola, with acid production from adonitol and l-sorbose and ability to use 3-phenylproprionate, 5-keto-d-gluconate and tricarballylic acid as sole carbon sources being particularly useful. Based on their genetic and phenotypic characteristics, we propose the names Klebsiella quasipneumoniae subsp. quasipneumoniae subsp. nov. and K. quasipneumoniae subsp. similipneumoniae subsp. nov. for strains of KpII-A and KpII-B, respectively. The type strain of K. quasipneumoniae sp. nov. and of K. quasipneumoniae subsp. quasipneumoniae subsp. nov. is 01A030(T) ( = SB11(T) = CIP 110771(T) = DSM 28211(T)). The type strain of K. quasipneumoniae subsp. similipneumoniae subsp. nov. is 07A044(T) ( = SB30(T) = CIP 110770(T) = DSM 28212(T)). Both strains were isolated from human blood cultures. This work also showed that Klebsiella singaporensis is a junior heterotypic synonym of K. variicola. © 2014 IUMS.

  16. 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

  17. 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....

  18. Lactococcus lactis metabolism and gene expression during growth on plant tissues.

    Science.gov (United States)

    Golomb, Benjamin L; Marco, Maria L

    2015-01-01

    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. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  19. 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.

  20. [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.

  1. 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.

  2. 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.

  3. Secretion of Kluyveromyces lactis Cu/Zn SOD: strategies for enhanced production.

    Science.gov (United States)

    Raimondi, Stefano; Uccelletti, Daniela; Amaretti, Alberto; Leonardi, Alan; Palleschi, Claudio; Rossi, Maddalena

    2010-04-01

    The Kluyveromyces lactis Cu/Zn SOD gene (SOD1) was fused with the toxin K1 signal sequence to obtain extracellular production of superoxide dismutase. Kluyveromyces marxianus L3 and K. lactis MW98-8C strains were transformed and compared as hosts for the secretion. The effects of the media composition were evaluated: In K. lactis, the highest volumetric activity was obtained in YKK synthetic medium in the presence of Cu(2+)/Zn(2+) cofactors (9.6 kU l(-1)). In K. marxianus, active SOD was produced only in YPD medium supplemented with Cu(2+) and Zn(2+) (8.8 kU l(-1)). In order to improve the production of secreted active SOD in K. lactis, the SOD1 copper carrier (CCS1) was overexpressed and targeted to the secretory apparatus. A positive effect was observed only when K. lactis was grown in a medium without Cu(2+)/Zn(2+) supplement. The best performing culture conditions for K. lactis and K. marxianus recombinant strains were successfully applied to two laboratory-scale fed-batch processes, and volumetric SOD activities increased up to 19.4 and 24.1 kU l(-1), respectively.

  4. Susceptibilidade antimicrobiana de Campylobacter fetus subsp. venerealis isolado de bovinos Antimicrobial susceptibility of Campylobacter fetus subsp. venerealis isolated from cattle

    Directory of Open Access Journals (Sweden)

    Agueda C. Vargas

    2005-03-01

    Full Text Available A campilobacteriose venérea bovina, ocasionada principalmente pelo Campylobacter fetus subsp. fetus e Campylobacter subsp. venerealis, é transmitida através do coito ou por inseminação com sêmen contaminado. O propósito deste estudo foi determinar a susceptibilidade in vitro de isolados de C. fetus subesp. venerealis a agentes antimicrobianos comumente utilizados para o tratamento clínico e de sêmen. Foram testadas duas cepas padrão, sendo uma de C. fetus subsp. fetus e outra de C. fetus subsp. venerealis, bem como 21 amostras de isolados clínicos de C. fetus subsp. venerealis. Os testes foram realizados conforme o método de Kirby-Bauer. A amostra padrão de C. fetus subsp. fetus demonstrou-se resistente à lincomicina, penicilina e ácido nalidíxico, enquanto a de C. fetus subsp. venerealis apresentou susceptibilidade a todos antimicrobianos testados, com exceção do ácido nalidíxico. Todas as amostras de C. fetus subsp. venerealis foram susceptíveis à amicacina, ampicilina, cefalotina, estreptomicina, gentamicina, penicilina e tetraciclina. Foi observada resistência de 42,86% à lincomicina e 4,76 % a enrofloxacina, e de 100% ao ácido nalidíxico. Ainda, 4,76% apresentaram susceptibilidade intermediária à enrofloxacina, neomicina e polimixina B e 9,52% à lincomicina. Os resultados evidenciaram a sensibilidade das amostras analisadas aos antimicrobianos comumente utilizados para o tratamento clínico e do sêmen.Venereal campylobacteriosis is associated with infection of Campylobacter fetus subsp. fetus and Campylobacter fetus subsp. venerealis. The etiological agent is transmitted by natural bull breeding or artificial insemination using contaminated semen. The present study aimed to determine the in vitro susceptibility of C. fetus subsp. venerealis isolates to antimicrobial drugs generally used in clinical and semen treatment. Reference strains of C. fetus subsp. fetus and C. fetus subsp. venerealis and 21 C. fetus

  5. Lactococcus lactis Thioredoxin Reductase Is Sensitive to Light Inactivation

    DEFF Research Database (Denmark)

    Björnberg, Olof; Viennet, Thibault; Skjoldager, Nicklas

    2015-01-01

    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......R. The rate of light inactivation under standardized conditions (λmax = 460 nm and 4 °C) was reduced at lowered oxygen concentrations and in the presence of iodide. Inactivation was accompanied by a distinct spectral shift of the flavin adenine dinucleotide (FAD) that remained firmly bound. High......-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...

  6. Investigation of glycerol assimilation and cofactor metabolism in Lactococcus lactis

    DEFF Research Database (Denmark)

    Holm, Anders Koefoed

    : anaerobic, aerobic and respiration permissive growth in combination with either glycerol as a sole substrate or with co-metabolization of glycerol with common sugar substrates. Although no growth on glycerol was seen, both positive and detrimental effects were observed from cultures with glycerol...... itself under both anaerobic and respiration permissive conditions, but was not found to have the same profound effect on other sugar substrates such as galactose or ribose. Supplementation of nucleosides to the growth medium or increased substrate concentration were found to counteract the inhibitory...... 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...

  7. Proteome analysis of the purine stimulon from Lactococcus lactis

    DEFF Research Database (Denmark)

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

    2003-01-01

    E, PurS, PurM, PurL), and enzymes involved in the generation of C1 units (GlyA, Fhs). Cl units are primarily required for purine biosynthesis. Upon analysis of the nucleotide sequence preceding the structural genes for these proteins in the L. lactis IL1403 genome sequence showed that all contained PurBox......-Pribnov box structures resembling the PurR activated promoters for the purDEK and purCSQLF operons. Most, and possibly all members of the Psu stimulon are thus members of the PurR regulon. Five Psu proteins could not be identified. The second stimulon, the Psd stimulon (purine starvation decreased), whose...... escaped identification. The last, Dcu (decoynine up-regulated), stimulon contained proteins whose synthesis escaped the severe general depression during inhibition of the GMP synthetase by decoynine. This regulon was comprised of mostly glycolytic enzymes (fructose bisphosphate aldolase, enolase, pyruvate...

  8. Prevalence of Streptococcus dysgalactiae subsp. equisimilis and S. equi subsp. zooepidemicus in a sample of healthy dogs, cats and horses.

    Science.gov (United States)

    Acke, E; Midwinter, A C; Lawrence, K; Gordon, S J G; Moore, S; Rasiah, I; Steward, K; French, N; Waller, A

    2015-09-01

    To estimate the prevalence of β-haemolytic Lancefield group C streptococci in healthy dogs, cats and horses; to determine if frequent contact with horses was associated with isolation of these species from dogs and cats; and to characterise recovered S. equi subsp. zooepidemicus isolates by multilocus sequence typing. Oropharyngeal swabs were collected from 197 dogs and 72 cats, and nasopharyngeal swabs from 93 horses. Sampling was carried out at the Massey University Veterinary Teaching Hospital, on sheep and beef farms or on premises where horses were present. All animals were healthy and were categorised as Urban dogs and cats (minimal contact with horses or farm livestock), Farm dogs (minimal contact with horses) and Stable dogs and cats (frequent contact with horses). Swabs were cultured for β-haemolytic Streptococcus spp. and Lancefield group C streptococcal subspecies were confirmed by phenotypic and molecular techniques. Of the 197 dogs sampled, 21 (10.7 (95% CI= 4.0-25.4)%) tested positive for S. dysgalactiae subsp. equisimilis and 4 (2.0 (95% CI=0.7-5.5)%) tested positive for S. equi subsp. zooepidemicus. All these isolates, except for one S. dysgalactiae subsp. equisimilis isolate in an Urban dog, were from Stable dogs. S. dysgalactiae subsp. equisimilis was isolated from one Stable cat. Of the 93 horses, 22 (23.7 (95% CI=12.3-40.6)%) and 6 (6.5 (95% CI=2.8-14.1)%) had confirmed S. dysgalactiae subsp. equisimilis and S. equi subsp. zooepidemicus isolation respectively. Isolation of S. dysgalactiae subsp. equisimilis from dogs was associated with frequent contact with horses (OR=9.8 (95% CI=2.6-72.8)). Three different multilocus sequence type profiles of S. equi subsp. zooepidemicus that have not been previously reported in dogs were recovered. Subclinical infection or colonisation by S. equi subsp. zooepidemicus and S. dysgalactiae subsp. equisimilis occurs in dogs and further research on inter-species transmission and the pathogenic potential of these

  9. Glycosylation in secreted proteins from yeast Kluyveromyces lactis

    Energy Technology Data Exchange (ETDEWEB)

    Santos, A.V.; Passos, F.M.L. [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Microbiologia. Lab. de Fisiologia de Microrganismos; Azevedo, B.R.; Pimenta, A.M.C.; Santoro, M.M. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Bioquimica e Imunologia. Lab. de Enzimologia e Fisico-Quimica de Proteina

    2008-07-01

    Full text: The nutritional status of a cell culture affects either the expression or the traffic of a number of proteins. The identification of the physiological conditions which favor protein secretion has important biotechnological consequences in designing systems for recombinant extracellular protein industrial production. Yeast Kluyvromyces lactis has been cultured in a continuous stirring tank bioreactor (CSTR) under nitrogen limitation at growth rates (0.03 h{sup -1} and 0.09 h{sup -1}) close to either exponential or stationary batch growth phases, respectively the objective was to investigate the extracellular glycoproteins at these two level of nitrogen limitation. Proteins from free cell extracts were separated by gradient SDS-PAGE (5-15%) and two-dimensional chromatography, and were analyzed by mass spectrometry (MALDI-TOF-TOF-MS). In SDS-PAGE analysis, differences in extracellular proteome were visualized: different proteins profiles at these two growth rates. The 0.09 h-1 growth rate showed larger number of bands using colloidal Coma ssie Blue staining. Different bands were detected at these two growth rates when the PAS assay for glycoprotein detection in polyacrylamide gel was used. The two-dimensional chromatogram profiles were comparatively distinguished between the 0.03 h{sup -1} and 0.09 h{sup -1} growth rate samples. Protein peaks from the second dimension, were subjected to mass spectrometry. The mass spectrums visualized showed glycosylated proteins with N-acetylglucosamine molecules and 8, 9 or 15 hexoses molecules. Comparisons between the proteins averaged mass values with the deduced proteins masses from K. lactis secreted proteins database indicated possible post-translational modifications, such as post-translational proteolysis, acetylation, deamidation and myristoylation.

  10. Molecular characterization of virulence genes of Streptococcus equi subsp. equi and Streptococcus equi subsp. zooepidemicus in equines

    OpenAIRE

    R. Javed; A. K. Taku; Rakhi Gangil; R. K. Sharma

    2016-01-01

    Aim: The aim was to determine the occurrence of streptococci in equines in Jammu (R. S. Pura, Katra), characterization of Streptococci equi subsp. equi and Streptococcus equi subsp. zooepidemicus with respect to their virulence traits and to determine antibiotic sensitivity pattern of virulent Streptococcus isolates. Materials and Methods: A total of 96 samples were collected from both clinically affected animals (exhibiting signs of respiratory tract disease) and apparently healthy animals a...

  11. 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

    Directory of Open Access Journals (Sweden)

    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

  12. Fermentation performance of lactic acid bacteria in different lupin substrates-influence and degradation ability of antinutritives and secondary plant metabolites.

    Science.gov (United States)

    Fritsch, C; Vogel, R F; Toelstede, S

    2015-10-01

    The main objectives were to determine the influence of secondary plant metabolites and antinutritives in lupin seeds on the fermentation performance of lactic acid bacteria and to study their ability to degrade these substances. The suitability of lupin raw materials as fermentation substrates was examined. To evaluate the fermentation performance, microbial growth, metabolite formation and substrate uptake in three different lupin substrates was monitored. On the one hand, a lupin protein isolate, which contained only trace amounts of phytochemicals was used in the study. On the other hand, the flour of Lupinus angustifolius cv. Boregine and the flour of the alkaloid rich lupin Lupinus angustifolius cv. Azuro were inoculated with Bifidobacterium animalis subsp. lactis, Pediococcus pentosaceus, Lactobacillus plantarum and Lactococcus lactis subsp. lactis. The micro-organisms showed no significant differences in the fermentation performance on the different lupin flours. Similarly, the growth of most strains on lupin protein isolate was comparable to that on the lupin flours. The fermentation with Bifidobacterium animalis subsp. lactis led to a significant decrease in flatulence causing oligosaccharides. During fermentation with Lactobacillus plantarum the phytic acid content was partially degraded. Neither the secondary plant metabolites nor the antinutritives of lupin flour inhibited the growth or metabolic activity of the tested micro-organisms. Therefore, lupin flour is suitable for lactic fermentation. Some strains showed the ability to degrade oligosaccharides or phytic acid. This work contributes to the fundamental knowledge of the metabolism of lactic acid bacteria during fermentation of lupin substrates. Fermentation of lupin raw materials could be used to improve the nutritional value of the substrates due to the reduction of antinutritives. © 2015 The Society for Applied Microbiology.

  13. 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

  14. The impact of a consortium of fermented milk strains on the gut microbiome of gnotobiotic mice and monozygotic twins.

    Science.gov (United States)

    McNulty, Nathan P; Yatsunenko, Tanya; Hsiao, Ansel; Faith, Jeremiah J; Muegge, Brian D; Goodman, Andrew L; Henrissat, Bernard; Oozeer, Raish; Cools-Portier, Stéphanie; Gobert, Guillaume; Chervaux, Christian; Knights, Dan; Lozupone, Catherine A; Knight, Rob; Duncan, Alexis E; Bain, James R; Muehlbauer, Michael J; Newgard, Christopher B; Heath, Andrew C; Gordon, Jeffrey I

    2011-10-26

    Understanding how the human gut microbiota and host are affected by probiotic bacterial strains requires carefully controlled studies in humans and in mouse models of the gut ecosystem where potentially confounding variables that are difficult to control in humans can be constrained. Therefore, we characterized the fecal microbiomes and metatranscriptomes of adult female monozygotic twin pairs through repeated sampling 4 weeks before, 7 weeks during, and 4 weeks after consumption of a commercially available fermented milk product (FMP) containing a consortium of Bifidobacterium animalis subsp. lactis, two strains of Lactobacillus delbrueckii subsp. bulgaricus, Lactococcus lactis subsp. cremoris, and Streptococcus thermophilus. In addition, gnotobiotic mice harboring a 15-species model human gut microbiota whose genomes contain 58,399 known or predicted protein-coding genes were studied before and after gavage with all five sequenced FMP strains. No significant changes in bacterial species composition or in the proportional representation of genes encoding known enzymes were observed in the feces of humans consuming the FMP. Only minimal changes in microbiota configuration were noted in mice after single or repeated gavage with the FMP consortium. However, RNA-Seq analysis of fecal samples and follow-up mass spectrometry of urinary metabolites disclosed that introducing the FMP strains into mice results in significant changes in expression of microbiome-encoded enzymes involved in numerous metabolic pathways, most prominently those related to carbohydrate metabolism. B. animalis subsp. lactis, the dominant persistent member of the FMP consortium in gnotobiotic mice, up-regulates a locus in vivo that is involved in the catabolism of xylooligosaccharides, a class of glycans widely distributed in fruits, vegetables, and other foods, underscoring the importance of these sugars to this bacterial species. The human fecal metatranscriptome exhibited significant changes

  15. 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

  16. 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.

  17. 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.

  18. Biofilm formation of Francisella noatunensis subsp. orientalis

    Science.gov (United States)

    Soto, Esteban; Halliday-Wimmonds, Iona; Francis , Stewart; Kearney, Michael T.; Hansen, John D.

    2015-01-01

    Francisella noatunensis subsp. orientalis (Fno) is an emergent fish pathogen in both marine and fresh water environments. The bacterium is suspected to persist in the environment even without the presence of a suitable fish host. In the present study, the influence of different abiotic factors such as salinity and temperature were used to study the biofilm formation of different isolates of Fno including intracellular growth loci C (iglC)and pathogenicity determinant protein A (pdpA) knockout strains. Finally, we compared the susceptibility of planktonic and biofilm to three disinfectants used in the aquaculture and ornamental fish industry, namely Virkon®, bleach and hydrogen peroxide. The data indicates that Fno is capable of producing biofilms within 24 h where both salinity as well as temperature plays a role in the growth and biofilm formation of Fno. Mutations in theiglC or pdpA, both known virulence factors, do not appear to affect the capacity of Fno to produce biofilms, and the minimum inhibitory concentration, and minimum biocidal concentration for the three disinfectants were lower than the minimum biofilm eradication concentration values. This information needs to be taken into account if trying to eradicate the pathogen from aquaculture facilities or aquariums.

  19. New phenylethanoids from Buddleja cordata subsp. cordata.

    Science.gov (United States)

    Acevedo, L; Martínez, E; Castañeda, P; Franzblau, S; Timmermann, B N; Linares, E; Bye, R; Mata, R

    2000-04-01

    Bioassay-guided fractionation of a crude extract of the stem bark of Buddleja cordata subsp. cordata with significant antimycobacterial activity led to the isolation of a mixture composed by ten new long-chain esters of 2[4'-hydroxyphenyl]-ethanol (1-10), along with the lichen metabolites methyl beta-orcinolcarboxylate (11) and beta-orcinolcarboxylate (12). Extensive HPLC allowed the separation of the major components of the mixture, which were characterized by spectral means as 2[4'-hydroxyphenyl]-ethyl stearate (3), 2[4'-hydroxyphenyl]-ethyl behenate (6), and 2[4'-hydroxyphenyl]-ethyl lignocerate (8). The minor esters were identified as 2[4'-hydroxyphenyl]-ethyl palmitate (1), 2[4'-hydroxyphenyl]-ethyl heptadecanoate (2), 2[4'-hydroxyphenyl]-ethyl nonadecanoate (4), 2[4'-hydroxyphenyl]-ethyl arachidate (5), 2[4'-hydroxyphenyl]-ethyl tricosanoate (7), 2[4'-hydroxyphenyl]-ethyl pentacosanoate (9), and 2[4'-hydroxyphenyl]-ethyl hexacosanoate (10) by GC-MS analysis of the methyl esters derivatives of the fatty acids obtained by alkaline hydrolysis of the mixture. Compound 8 exhibited moderate antibacterial activity against Mycobacterium tuberculosis (MIC = 64 micrograms/ml).

  20. Molecular characterization of virulence genes of Streptococcus equi subsp. equi and Streptococcus equi subsp. zooepidemicus in equines

    Science.gov (United States)

    Javed, R.; Taku, A. K.; Gangil, Rakhi; Sharma, R. K.

    2016-01-01

    Aim: The aim was to determine the occurrence of streptococci in equines in Jammu (R. S. Pura, Katra), characterization of Streptococci equi subsp. equi and Streptococcus equi subsp. zooepidemicus with respect to their virulence traits and to determine antibiotic sensitivity pattern of virulent Streptococcus isolates. Materials and Methods: A total of 96 samples were collected from both clinically affected animals (exhibiting signs of respiratory tract disease) and apparently healthy animals and were sent to laboratory. The organisms were isolated on Columbia nalidixic acid agar containing 5% sheep blood as well as on sheep blood agar and confirmed by cultural characteristics and biochemical tests. Molecular detection of Streptococcus was done directly from cultures using sodA and seM gene-based polymerase chain reaction (PCR). Antibiogram was performed against five antibiotics such as amoxicillin, penicillin G, streptomycin, rifampicin, and methicillin. Results: During this study, a total 40 streptococcal isolates were obtained out of which 2 isolates were of S. equi subsp. equi, 12 isolates were from S. equi subsp. zooepidemicus. In the PCR-based detection, we revealed amplicons of 235 bp and 679 bp for confirmation of sodA and seM gene, respectively. In antibiogram, two isolates of S. equi subsp. equi were found resistant to penicillin G, and all other isolates were found sensitive to amoxicillin and streptomycin. Conclusion: The majority of streptococcal infections was due to S. equi subsp. Zooepidemicus, and thus was recognized as a potential pathogen of diseases of equines besides S. equi subsp. equi. PMID:27651677

  1. Molecular characterization of virulence genes of Streptococcus equi subsp. equi and Streptococcus equi subsp. zooepidemicus in equines

    Directory of Open Access Journals (Sweden)

    R. Javed

    2016-08-01

    Full Text Available Aim: The aim was to determine the occurrence of streptococci in equines in Jammu (R. S. Pura, Katra, characterization of Streptococci equi subsp. equi and Streptococcus equi subsp. zooepidemicus with respect to their virulence traits and to determine antibiotic sensitivity pattern of virulent Streptococcus isolates. Materials and Methods: A total of 96 samples were collected from both clinically affected animals (exhibiting signs of respiratory tract disease and apparently healthy animals and were sent to laboratory. The organisms were isolated on Columbia nalidixic acid agar containing 5% sheep blood as well as on sheep blood agar and confirmed by cultural characteristics and biochemical tests. Molecular detection of Streptococcus was done directly from cultures using sodA and seM gene-based polymerase chain reaction (PCR. Antibiogram was performed against five antibiotics such as amoxicillin, penicillin G, streptomycin, rifampicin, and methicillin. Results: During this study, a total 40 streptococcal isolates were obtained out of which 2 isolates were of S. equi subsp. equi, 12 isolates were from S. equi subsp. zooepidemicus. In the PCR-based detection, we revealed amplicons of 235 bp and 679 bp for confirmation of sodA and seM gene, respectively. In antibiogram, two isolates of S. equi subsp. equi were found resistant to penicillin G, and all other isolates were found sensitive to amoxicillin and streptomycin. Conclusion: The majority of streptococcal infections was due to S. equi subsp. Zooepidemicus, and thus was recognized as a potential pathogen of diseases of equines besides S. equi subsp. equi.

  2. Anoxybacillus kamchatkensis subsp. asaccharedens subsp. nov., a thermophilic bacterium isolated from a hot spring in Batman.

    Science.gov (United States)

    Gul-Guven, Reyhan; Guven, Kemal; Poli, Annarita; Nicolaus, Barbara

    2008-12-01

    A new thermophilic spore-forming strain KG8(T) was isolated from the mud of Taslidere hot spring in Batman. Strain KG8(T) was aerobe, Gram-positive, rod-shaped, motile, occurring in pairs or filamentous. Growth was observed from 35-65 degrees C (optimum 55 degrees C) and at pH 5.5-9.5 (optimum pH 7.5). It was capable of utilizing starch, growth was observed until 3% NaCl (w/v) and it was positive for nitrate reduction. On the basis of 16S rRNA gene sequence similarity, strain KG8(T) was shown to be related most closely to Anoxybacillus species. Chemotaxonomic data (major isoprenoid quinone-menaquinone-7; major fatty acid-iso-C15:0 and iso-C17:0) supported the affiliation of strain KG8(T) to the genus Anoxybacillus. The results of DNA-DNA hybridization, physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain KG8(T). Based on these results we propose assigning a novel subspecies of Anoxybacillus kamchatkensis, to be named Anoxybacillus kamchatkensis subsp. asaccharedens subsp. nov. with the type strain KG8(T) (DSM 18475(T)=CIP 109280(T)).

  3. Common genomic features of Campylobacter jejuni subsp. doylei strains distinguish them from C. jejuni subsp. jejuni

    Directory of Open Access Journals (Sweden)

    Horn Sharon T

    2007-05-01

    Full Text Available Abstract Background Campylobacter jejuni has been divided into two subspecies: C. jejuni subsp. jejuni (Cjj and C. jejuni subsp. doylei (Cjd. Nearly all of the C. jejuni strains isolated are Cjj; nevertheless, although Cjd strains are isolated infrequently, they differ from Cjj in two key aspects: they are obtained primarily from human clinical samples and are associated often with bacteremia, in addition to gastroenteritis. In this study, we utilized multilocus sequence typing (MLST and a DNA microarray-based comparative genomic indexing (CGI approach to examine the genomic diversity and gene content of Cjd strains. Results A geographically diverse collection of eight Cjd strains was examined by MLST and determined to be phylogenetically distinct from Cjj strains. Microarray-based CGI approach also supported this. We were able to demonstrate that Cjd strains exhibited divergence from Cjj strains NCTC 11168 and RM1221 in many of the intraspecies hypervariable regions. Moreover, multiple metabolic, transport and virulence functions (e.g. cytolethal distending toxin were shown to be absent in the Cjd strains examined. Conclusion Our data demonstrate that Cjd are phylogenetically distinct from Cjj strains. Using the CGI approach, we identified subsets of absent genes from amongst the C. jejuni genes that provide clues as to the potential evolutionary origin and unusual pathogenicity of Cjd.

  4. Potential Transmission Pathways of Streptococcus gallolyticus subsp. gallolyticus.

    Directory of Open Access Journals (Sweden)

    Jessika Dumke

    Full Text Available Streptococcus gallolyticus subsp. gallolyticus (S. gallolyticus subsp. gallolyticus, a member of group D streptococci, is an inhabitant of the animal and human gastrointestinal tract. Furthermore, it is a facultative pathogen which causes e.g. endocarditis, septicemia and mastitis. S. gallolyticus subsp. gallolyticus may be transmitted either directly or indirectly between animals and humans. However, the transmission routes are an unsolved issue. In this study, we present systematic analyses of an S. gallolyticus subsp. gallolyticus isolate of an infective endocarditis patient in relation to isolates of his laying hen flock. Isolates from pooled droppings of laying hens, pooled dust samples and human blood culture were characterized by using multilocus sequence typing (MLST and DNA fingerprinting. MLST revealed the same allelic profile of isolates from the human blood culture and from the droppings of laying hens. In addition, these isolates showed clonal identity regarding a similar DNA fingerprinting pattern. For the first time, we received a hint that transmission of S. gallolyticus subsp. gallolyticus between poultry and humans may occur. This raises the question about the zoonotic potential of isolates from poultry and should be considered in future studies.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Fermentation-induced variation in heat and oxidative stress phenotypes of Lactococcus lactis MG1363 reveals transcriptome signatures for robustness

    NARCIS (Netherlands)

    Dijkstra, A.R.; Alkema, W.; Starrenburg, M.J.C.; Hugenholtz, J.; van Hijum, S.A.F.T.; Bron, P.A.

    2014-01-01

    Background: Lactococcus lactis is industrially employed to manufacture various fermented dairy products. The most cost-effective method for the preservation of L. lactis starter cultures is spray drying, but during this process cultures encounter heat and oxidative stress, typically resulting in low

  11. 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

  12. A single or multistage mycobacterium avium subsp. paratuberculosis subunit vaccine

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention provides one or more immunogenic polypeptides for use in a preventive or therapeutic vaccine against latent or active infection in a human or animal caused by a Mycobacterium species, e.g. Mycobacterium avium subsp. paratuberculosis. Furthermore a single or multi-phase vaccine...... comprising the one or more immunogenic polypeptides is provided for administration for the prevention or treatment of infection with a Mycobacterium species, e.g. Mycobacterium avium subsp. paratuberculosis. Additionally, nucleic acid vaccines, capable of in vivo expression of the multi-phase vaccine...... comprising the one or more immunogenic polypeptides, is provided for prevention or treatment of infection with a Mycobacterium species, e.g. Mycobacterium avium subsp. paratuberculosis....

  13. Campylobacter hyointestinalis subsp hyointestinalis, a common Campylobacter species in reindeer

    DEFF Research Database (Denmark)

    Hanninen, M.L.; Sarelli, L.; Sukura, A.

    2002-01-01

    Aims: To study the prevalence of Campylobacter spp. in the faecal material of reindeer, and to identify the isolates by means of a polyphasic approach. In addition, to study the genetic diversity of Camp. hyointestinalis subsp. hyointestinalis reindeer isolates by pulsed-field gel electrophoresis...... slaughterhouses. Samples were cultured by methods suitable for isolation of fastidious Campylobacter species. Of all samples, 6% (24/399) were Campylobacter-positive. Phenotypic characteristics, SDS-PAGE protein patterns, dot blot DNA-DNA hybridization, 23S rDNA restriction fragment polymorphism analysis and PFGE...... identified the isolates as Camp. hyointestinalis subsp. kyointestinalis. Conclusions: Campylobacter hyointestinalis subsp. hyointestinalis was the only Campylobacter species isolated from reindeer in this study. The isolates showed high genomic diversity in PFGE with the restriction enzymes SmaI and Kpn...

  14. 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.

  15. Some chemical properties of nisin produced by lactococcus lactis

    International Nuclear Information System (INIS)

    Hussein, H.; Abdel Karem, H.; El-Hadedy, D.; Badr, S.

    2010-01-01

    The present study was carried out to study the properties of nisin produced by lactococcus lactis FG 2 isolated from local un fated cheese. The maximum anti-microbial effect of pure nisin was occurred at ph 6 and 7. Nisin was heat stable from 40 to 90 degree C for 30 min. Molecular weight of nisin was determined by SDS-PAGE, it was 3.0 kDa and after irradiated the microbial cells to 1.5 kGy dose level the molecular weight increased to 3.5 t kDa then decreased at 2 kGy . Storage for two weeks it appeared in dimmer means and had a molecular weight 7 kDa . Using amino acid analyzer reveled that nisin contained a majority of nonpolar amino acids and exhibited cystine in composition . Nisin produced in whey have higher activity than nisin produced in MRS medium but both had the same structure. The results proved that nisin gene is in coded in chromosome and not with plasmid.

  16. A single or multistage mycobacterium avium subsp. paratuberculosis subunit vaccine

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention provides one or more immunogenic polypeptides for use in a preventive or therapeutic vaccine against latent or active infection in a human or animal caused by a Mycobacterium species, e.g. Mycobacterium avium subsp. paratuberculosis. Furthermore a single or multi-phase vaccine...... comprising the one or more immunogenic polypeptides is provided for administration for the prevention or treatment of infection with a Mycobacterium species, e.g. Mycobacterium avium subsp. paratuberculosis. Additionally, nucleic acid vaccines, capable of in vivo expression of the multi-phase vaccine...

  17. 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.

  18. 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...

  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. Enhancement of nisin production in milk by conjugal transfer of the protease-lactose plasmid pLP712 to the wild strain Lactococcus lactis UQ2

    OpenAIRE

    García-Parra, María D.; Campelo, Ana B.; García-Almendárez, Blanca E.; Regalado, Carlos; Rodríguez González, Ana; Martínez Fernández, Beatriz

    2010-01-01

    Lactococcus lactis UQ2 is a wild nisin A producer isolated from a Mexican cheese that grows poorly in milk. Conjugal matings with L. lactis NCDO712 to transfer the Lac+ Prt+ plasmid pLP712 and selection with nisin and lactose yielded L. lactis NCDO712 NisA+. Naturally rifampicin resistant L. lactis UQ2Rif was isolated to provide an additional selective marker. The identity of a transconjugant L. lactis UQ2Rif Lac+ was confirmed by RAPD-PCR fingerprinting, nisA PCR amplification, nisin product...

  1. 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.

  2. 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.

  3. 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.

  4. The influence of whey protein concentrate on growth and survival of probiotic bacteria in whey

    Directory of Open Access Journals (Sweden)

    Ljubica Tratnik

    2008-08-01

    Full Text Available This research examines the influence of whey protein concentrate addition (WPC on growth and activity of probiotic species Lactobacilus acidophilus La-5 and Bifidobacterium animalis subsp. lactis BB-12 in sweet reconstituted whey and their survival during 28 days of fermented whey cold storage (4 °C. The fermentation of whey at 37º C with and without 1.5 and 3% of WPC addition has been observed. Fermentation of whey with Lactobacillus acidophilus La-5 to which 3% WPC was added, was about an hour shorter (∼ 14 hours compared to the fermentation of whey without WPC addition (∼ 15 hours. The viable cells count of Lactobacilus acidophilus La-5 was better in whey with 3% of WPC addition (Δlog CFU/mL = 2.1 compared to whey without WPC addition (Δlog CFU/mL = 1.7 . Addition of whey protein concentrate did not influence significantly on growth of Bifidobacterium animalis subsp. lactis BB-12 in whey, and also it did not influence the survival of both probiotic species during 28 days of cool storage (at 4 °C. Whey enriched with WPC had slightly higher titratable acidity during fermentation and storage compared to whey without WPC addition.

  5. Vitaliana primuliflora subsp. assoana. Nueva cita para la Comunidad Valenciana (Vitaliana primuliflora subsp. assoana, new record for valencian flora

    Directory of Open Access Journals (Sweden)

    Amparo OLIVARES

    2012-04-01

    Full Text Available Se comunica el hallazgo de una localidad situada entre el límite noroeste de la provincia de Valencia y el sureste de la de Teruel donde se ha encontrado Vitaliana primuliflora subsp. assoana, nueva población de esta especie para la Comunidad Valenciana.SUMMARY: This paper reports the discovery of a new location from the northwest boundary of the province of Valencia and south of Teruel (E Spain where found Vitaliana primuliflora subsp. assoana, new population of this species to Valencia.

  6. Fusobacterium nucleatum subsp. fusiforme Gharbia and Shah 1992 is a later synonym of Fusobacterium nucleatum subsp. vincentii Dzink et al. 1990.

    Science.gov (United States)

    Kook, Joong-Ki; Park, Soon-Nang; Lim, Yun Kyong; Choi, Mi-Hwa; Cho, Eugene; Kong, Si-Won; Shin, Yeseul; Paek, Jayoung; Chang, Young-Hyo

    2013-04-01

    On the basis of the DNA-DNA hybridization patterns and phenotypic characteristics, Fusobacterium nucleatum was classified into five subspecies. Previous studies have suggested that F. nucleatum subsp. vincentii is genetically similar to F. nucleatum subsp. fusiforme. The aim of this study was to investigate the possibility of classifying these two subspecies into a single subspecies by phylogenetic analysis using a single sequence (24,715 bp) concatenated 22 housekeeping genes of eight F. nucleatum strains including type strains of five F. nucleatum subspecies. The phylogenetic analysis indicated that F. nucleatum subsp. vincentii and F. nucleatum subsp. fusiforme were clustered in the same group and each strain of other F. nucleatum subspecies were also separated into the same cluster. These results suggested that F. nucleatum subsp. fusiforme and F. nucleatum subsp. vincentii can be classified into a single subspecies. F. nucleatum subsp. vincentii was early published name; therefore, F. nucleatum subsp. fusiforme Gharbia and Shah 1992 can be regarded as a later synonym of F. nucleatum subsp. vincentii Dzink et al. 1990.

  7. Secretion of biologically active interferon-gamma inducible protein-10 (IP-10) by Lactococcus lactis.

    Science.gov (United States)

    Villatoro-Hernandez, Julio; Loera-Arias, Maria J; Gamez-Escobedo, Anali; Franco-Molina, Moises; Gomez-Gutierrez, Jorge G; Rodriguez-Rocha, Humberto; Gutierrez-Puente, Yolanda; Saucedo-Cardenas, Odila; Valdes-Flores, Jesus; Montes-de-Oca-Luna, Roberto

    2008-07-28

    Chemokines are a large group of chemotactic cytokines that regulate and direct migration of leukocytes, activate inflammatory responses, and are involved in many other functions including regulation of tumor development. Interferon-gamma inducible-protein-10 (IP-10) is a member of the C-X-C subfamily of the chemokine family of cytokines. IP-10 specifically chemoattracts activated T lymphocytes, monocytes, and NK cells. IP-10 has been described also as a modulator of other antitumor cytokines. These properties make IP-10 a novel therapeutic molecule for the treatment of chronic and infectious diseases. Currently there are no suitable live biological systems to produce and secrete IP-10. Lactococcus lactis has been well-characterized over the years as a safe microorganism to produce heterologous proteins and to be used as a safe, live vaccine to deliver antigens and cytokines of interest. Here we report a recombinant strain of L. lactis genetically modified to produce and secrete biologically active IP-10. The IP-10 coding region was isolated from human cDNA and cloned into an L. lactis expression plasmid under the regulation of the pNis promoter. By fusion to the usp45 secretion signal, IP-10 was addressed out of the cell. Western blot analysis demonstrated that recombinant strains of L. lactis secrete IP-10 into the culture medium. Neither degradation nor incomplete forms of IP-10 were detected in the cell or supernatant fractions of L. lactis. In addition, we demonstrated that the NICE (nisin-controlled gene expression) system was able to express IP-10 "de novo" even two hours after nisin removal. This human IP-10 protein secreted by L. lactis was biological active as demonstrated by Chemotaxis assay over human CD3+T lymphocytes. Expression and secretion of mature IP-10 was efficiently achieved by L. lactis forming an effective system to produce IP-10. This recombinant IP-10 is biologically active as demonstrated by its ability to chemoattract human CD3+ T

  8. Secretion of biologically active interferon-gamma inducible protein-10 (IP-10 by Lactococcus lactis

    Directory of Open Access Journals (Sweden)

    Saucedo-Cardenas Odila

    2008-07-01

    Full Text Available Abstract Background Chemokines are a large group of chemotactic cytokines that regulate and direct migration of leukocytes, activate inflammatory responses, and are involved in many other functions including regulation of tumor development. Interferon-gamma inducible-protein-10 (IP-10 is a member of the C-X-C subfamily of the chemokine family of cytokines. IP-10 specifically chemoattracts activated T lymphocytes, monocytes, and NK cells. IP-10 has been described also as a modulator of other antitumor cytokines. These properties make IP-10 a novel therapeutic molecule for the treatment of chronic and infectious diseases. Currently there are no suitable live biological systems to produce and secrete IP-10. Lactococcus lactis has been well-characterized over the years as a safe microorganism to produce heterologous proteins and to be used as a safe, live vaccine to deliver antigens and cytokines of interest. Here we report a recombinant strain of L. lactis genetically modified to produce and secrete biologically active IP-10. Results The IP-10 coding region was isolated from human cDNA and cloned into an L. lactis expression plasmid under the regulation of the pNis promoter. By fusion to the usp45 secretion signal, IP-10 was addressed out of the cell. Western blot analysis demonstrated that recombinant strains of L. lactis secrete IP-10 into the culture medium. Neither degradation nor incomplete forms of IP-10 were detected in the cell or supernatant fractions of L. lactis. In addition, we demonstrated that the NICE (nisin-controlled gene expression system was able to express IP-10 "de novo" even two hours after nisin removal. This human IP-10 protein secreted by L. lactis was biological active as demonstrated by Chemotaxis assay over human CD3+T lymphocytes. Conclusion Expression and secretion of mature IP-10 was efficiently achieved by L. lactis forming an effective system to produce IP-10. This recombinant IP-10 is biologically active as

  9. 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...

  10. Multi-stress resistance in Lactococcus lactis is actually escape from purine-induced stress sensitivity

    DEFF Research Database (Denmark)

    Ryssel, Mia; Hviid, Anne-Mette Meisner; Dawish, Mohamed S.

    2014-01-01

    in the rich and complex M17 medium. When salvage of purines and subsequent conversion to GTP was permitted in various genetic backgrounds of L. lactis MG1363, the cells became sensitive to acid stress, indicating that an excess of guanine nucleotides induces stress sensitivity. The addition of phosphate...... nucleotides is formed as a result of an improved conversion of guanosine in the salvage pathway. Based upon our findings, we suggest that L. lactis MG1363 is naturally multi-stress resistant in habitats devoid of any purine source. However, any exogenous purine that results in increased guanine nucleotide...

  11. Mycotoxin production by isolates of Fusarium lactis from greenhouse sweet pepper (Capsicum annuum).

    Science.gov (United States)

    Yang, Y; Bouras, N; Yang, J; Howard, R J; Strelkov, S E

    2011-12-02

    Internal fruit rot, caused by Fusarium lactis, is an important disease of sweet pepper (Capsicum annuum) in Canadian greenhouses. Production of the mycotoxins fumonisin B₁ (FB₁), moniliformin (MON) and beauvericin (BEA) by F. lactis (17 isolates) and the related species F. proliferatum (three isolates) and F. verticillioides (one isolate), which are also associated with internal fruit rot, was evaluated on rice medium. All 21 isolates examined were found to produce BEA, at concentrations ranging from 13.28 to 1674.60 ppm, while 13 of 17 F. lactis isolates and two of three F. proliferatum isolates produced MON (0.23 to 181.85 ppm). Only one isolate of F. lactis produced detectable levels of FB₁ in culture, whereas all three F. proliferatum isolates and the F. verticilloides isolate produced this mycotoxin (0.28 to 314 ppm). Production of FB₁, MON and BEA was also evaluated in inoculated pepper fruits showing mild or severe symptoms of infection. FB₁ could be detected in both lightly and heavily diseased fruit tissue after inoculation with F. lactis, F. proliferatum or F. verticilloides, at concentrations ranging from 0.61 to 8.04 ppm. BEA was also detected in lightly and heavily diseased fruit tissue inoculated with F. lactis, as well as in heavily diseased tissue inoculated with F. proliferatum (3.00 to 19.43 ppm), but not in tissue inoculated with F. verticilloides. MON was detected in all tissues inoculated with F. proliferatum or F. verticilloides, and in heavily diseased tissue inoculated with F. lactis (0.03 to 0.27 ppm). The three mycotoxins were also found in naturally infected sweet pepper fruits exhibiting symptoms of internal fruit rot and collected from a commercial greenhouse. The production of MON, BEA and FB₁ alone or in combination by isolates of F. lactis suggests that development of internal fruit rot of sweet pepper is an important food safety concern, and that every effort should be made to cull infected fruit before it makes it to

  12. Laminaria japonica Extract, an Inhibitor of Clavibater michiganense Subsp. Sepedonicum.

    Directory of Open Access Journals (Sweden)

    Jin Cai

    Full Text Available Bacterial ring rot of potato is one of the most serious potato plant and tuber diseases. Laminaria japonica extract was investigated for its antimicrobial activity against Clavibater michiganense subsp. sepedonicum (Spieckermann & Kotthoff Davis et al., the causative agent of bacterial ring rot of potato. The results showed that the optimum extraction conditions of antimicrobial substances from L. japonica were an extraction temperature of 80°C, an extraction time of 12 h, and a solid to liquid ratio of 1∶25. Active compounds of L. japonica were isolated by solvent partition, thin layer chromatography (TLC and column chromatography. All nineteen fractionations had antimicrobial activities against C. michiganense subsp. sepedonicum, while Fractionation three (Fr.3 had the highest (P<0.05 antimicrobial activity. Chemical composition analysis identified a total of 26 components in Fr.3. The main constituents of Fr.3 were alkanes (80.97%, esters (5.24%, acids (4.87% and alcohols (2.21%. Antimicrobial activity of Fr.3 against C. michiganense subsp. sepedonicum could be attributed to its ability to damage the cell wall and cell membrane, induce the production of reactive oxygen species (ROS, increase cytosolic Ca2+ concentration, inhibit the glycolytic pathway (EMP and tricarboxylic acid (TCA cycle, inhibit protein and nucleic acid synthesis, and disrupt the normal cycle of DNA replication. These findings indicate that L. japonica extracts have potential for inhibiting C. michiganense subsp. sepedonicum.

  13. Laminaria japonica Extract, an Inhibitor of Clavibater michiganense Subsp. Sepedonicum.

    Science.gov (United States)

    Cai, Jin; Feng, Jia; Xie, Shulian; Wang, Feipeng; Xu, Qiufeng

    2014-01-01

    Bacterial ring rot of potato is one of the most serious potato plant and tuber diseases. Laminaria japonica extract was investigated for its antimicrobial activity against Clavibater michiganense subsp. sepedonicum (Spieckermann & Kotthoff) Davis et al., the causative agent of bacterial ring rot of potato. The results showed that the optimum extraction conditions of antimicrobial substances from L. japonica were an extraction temperature of 80°C, an extraction time of 12 h, and a solid to liquid ratio of 1∶25. Active compounds of L. japonica were isolated by solvent partition, thin layer chromatography (TLC) and column chromatography. All nineteen fractionations had antimicrobial activities against C. michiganense subsp. sepedonicum, while Fractionation three (Fr.3) had the highest (P<0.05) antimicrobial activity. Chemical composition analysis identified a total of 26 components in Fr.3. The main constituents of Fr.3 were alkanes (80.97%), esters (5.24%), acids (4.87%) and alcohols (2.21%). Antimicrobial activity of Fr.3 against C. michiganense subsp. sepedonicum could be attributed to its ability to damage the cell wall and cell membrane, induce the production of reactive oxygen species (ROS), increase cytosolic Ca2+ concentration, inhibit the glycolytic pathway (EMP) and tricarboxylic acid (TCA) cycle, inhibit protein and nucleic acid synthesis, and disrupt the normal cycle of DNA replication. These findings indicate that L. japonica extracts have potential for inhibiting C. michiganense subsp. sepedonicum.

  14. Mycobacterium avium subsp. paratuberculosis infection, immunology and pathology of livestock

    Science.gov (United States)

    Mycobacterium avium subsp. paratuberculosis (MAP) infection in ruminants leads to a chronic and progressive enteric disease (Johne’s disease) that results in loss of intestinal function, poor body condition, and eventual death. Transmission is primarily through a fecal-oral route in neonates but con...

  15. Comparative genomics of extrachromosomal elements in Bacillus thuringiensis subsp. israelensis.

    Science.gov (United States)

    Bolotin, Alexandre; Gillis, Annika; Sanchis, Vincent; Nielsen-LeRoux, Christina; Mahillon, Jacques; Lereclus, Didier; Sorokin, Alexei

    2017-05-01

    Bacillus thuringiensis subsp. israelensis is one of the most important microorganisms used against mosquitoes. It was intensively studied following its discovery and became a model bacterium of the B. thuringiensis species. Those studies focused on toxin genes, aggregation-associated conjugation, linear genome phages, etc. Recent announcements of genomic sequences of different strains have not been explicitly related to the biological properties studied. We report data on plasmid content analysis of four strains using ultra-high-throughput sequencing. The strains were commercial product isolates, with their putative ancestor and type B. thuringiensis subsp. israelensis strain sequenced earlier. The assembled contigs corresponding to published and novel data were assigned to plasmids described earlier in B. thuringiensis subsp. israelensis and other B. thuringiensis strains. A new 360 kb plasmid was identified, encoding multiple transporters, also found in most of the earlier sequenced strains. Our genomic data show the presence of two toxin-coding plasmids of 128 and 100 kb instead of the reported 225 kb plasmid, a co-integrate of the former two. In two of the sequenced strains, only a 100 kb plasmid was present. Some heterogeneity exists in the small plasmid content and structure between strains. These data support the perception of active plasmid exchange among B. thuringiensis subsp. israelensis strains in nature. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  16. Molecular Characterization of Bartonella vinsonii subsp. berkhoffii Genotype III▿

    Science.gov (United States)

    Cadenas, Maria B.; Bradley, Julie; Maggi, Ricardo G.; Takara, Matt; Hegarty, Barbara C.; Breitschwerdt, Edward B.

    2008-01-01

    The molecular characterization of a Bartonella vinsonii subsp. berkhoffii genotype III strain (NCSU strain 06-CO1) isolated from the blood of a military working dog diagnosed with endocarditis is reported in this study. Several genes were amplified and sequenced for comparative sequence similarity with other strains. PMID:18367567

  17. New Iridoid Glycosides from Lamium eriocephalum subsp. eriocephalum

    DEFF Research Database (Denmark)

    Yalcin, Funda Nuray; Ersöz, Tayfun; Avci, Kürsat

    2007-01-01

    Two new iridoid glycosides, eriobioside (1) and lamerioside (2) were isolated from the aerial parts of Lamium eriocephalum subsp. eriocephalum, along with two known componds, lamiide (3) and ipolamiide (4). Their structures were elucidated by spectroscopic methods (UV, 1D- and 2D-NMR) and by mass...

  18. Fitness and its variation among populations of Acacia tortilis subsp ...

    African Journals Online (AJOL)

    Administrator

    2008-07-23

    Jul 23, 2008 ... Acacia tortilis subsp. raddiana (Fabaceae) plays an important role in the life of desert animals and is a major source of livestock feed ... raddiana grows in desert wadis and sandy plains, usually in water catchments areas in ...... Randomization and Monte Carlo Methods in Biology. Chapman & Hall, London.

  19. Streptococcus equi subsp. zooepidemicus Infections Associated with Guinea Pigs

    Science.gov (United States)

    Young, Andrea; Levine, Seth J.; Garvin, Joseph P.; Brown, Susan; Turner, Lauren; Fritzinger, Angela; Gertz, Robert E.; Murphy, Julia M.; Vogt, Marshall; Beall, Bernard

    2015-01-01

    Streptococcus equi subsp. zooepidemicus is a known zoonotic pathogen. In this public health investigation conducted in Virginia, USA, in 2013, we identified a probable family cluster of S. zooepidemicus cases linked epidemiologically and genetically to infected guinea pigs. S. zooepidemicus infections should be considered in patients who have severe clinical illness and report guinea pig exposure. PMID:25531424

  20. Recurrent Streptococcus equi subsp. zooepidemicus Bacteremia in an Infant.

    Science.gov (United States)

    Watson, Joshua R; Leber, Amy; Velineni, Sridhar; Timoney, John F; Ardura, Monica I

    2015-09-01

    We describe a case of an infant with recurrent bacteremia caused by Streptococcus equi subsp. zooepidemicus, likely transmitted from mother to infant. Our case highlights the importance of an epidemiological history and molecular diagnostics in ascertaining insights into transmission, pathogenesis, and optimal management. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  1. Complete Genome Sequence of Beijerinckia indica subsp. indica▿

    Science.gov (United States)

    Tamas, Ivica; Dedysh, Svetlana N.; Liesack, Werner; Stott, Matthew B.; Alam, Maqsudul; Murrell, J. Colin; Dunfield, Peter F.

    2010-01-01

    Beijerinckia indica subsp. indica is an aerobic, acidophilic, exopolysaccharide-producing, N2-fixing soil bacterium. It is a generalist chemoorganotroph that is phylogenetically closely related to facultative and obligate methanotrophs of the genera Methylocella and Methylocapsa. Here we report the full genome sequence of this bacterium. PMID:20601475

  2. Complete genome sequence of Beijerinckia indica subsp. indica.

    Science.gov (United States)

    Tamas, Ivica; Dedysh, Svetlana N; Liesack, Werner; Stott, Matthew B; Alam, Maqsudul; Murrell, J Colin; Dunfield, Peter F

    2010-09-01

    Beijerinckia indica subsp. indica is an aerobic, acidophilic, exopolysaccharide-producing, N(2)-fixing soil bacterium. It is a generalist chemoorganotroph that is phylogenetically closely related to facultative and obligate methanotrophs of the genera Methylocella and Methylocapsa. Here we report the full genome sequence of this bacterium.

  3. Factors affecting survival of Clavibacter michiganesis subsp. sepedonicus in water

    NARCIS (Netherlands)

    Wolf, van der J.M.; Beckhoven, van J.R.C.M.

    2004-01-01

    The survival of Clavibacter michiganensis subsp. sepedonicus (Cms), the causal organism of bacterial ring rot in potato, was studied in water, to assess the risks for dissemination of Cms via surface water and infection of potato crops by irrigation. Cms was able to survive for a maximum period of 7

  4. The effects of aqueous root extract of Senna italica subsp ...

    African Journals Online (AJOL)

    The effects of aqueous root extracts of Senna italica subsp. arachoides on the feeding performance of adults of Hyalomma marginatum rufipes in three consecutive infestations of rabbits were studied under laboratory conditions. Rabbits were divided into treatment group (n = 3), fed aqueous root extracts and rabbit pellets ...

  5. Knowledge on Sclerocarya birrea subsp. caffra with emphasis on its ...

    African Journals Online (AJOL)

    Knowledge on Sclerocarya birrea subsp. caffra with emphasis on its importance as a non-timber forest product in South and southern Africa: a summary: part 2: commercial use, tenure and policy, domestication, intellectual property rights and benefit-sharing: review paper.

  6. Plant regeneration of Brassica oleracea subsp. italica (Broccoli) CV ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-06-03

    Jun 3, 2009 ... Department of Agriculture Technology, Faculty of Agriculture, Universiti Putra Malaysia, 43400 Serdang, Selangor Darul. Ehsan, Malaysia. Accepted 20 March, 2009. Hypocotyls and shoot tips were used as explants in in vitro plant regeneration of broccoli (Brassica oleracea subsp.italica) cv. Green Marvel.

  7. Fitness and its variation among populations of Acacia tortilis subsp ...

    African Journals Online (AJOL)

    Therefore, this study aims to determine if A. tortilis subsp. raddiana populations suffer reduced fitness and its correlation or association with genetic diversity and mating parameters. Correlations and association between fitness, population size, genetic variation, and mating system parameters were tested using Spearman ...

  8. Sensitive and rapid detection of Mycoplasma capricolum subsp ...

    African Journals Online (AJOL)

    SAM

    2014-05-21

    May 21, 2014 ... The LAMP assay was able to detect MCCP in tissue. Key words: Mycoplasma capricolum subsp. Capripneumoniae, loop-mediated isothermal amplification, rapid detection. INTRODUCTION. Contagious caprine pleuropneumonia (CCPP) is a severe infectious disease of goats caused by Mycoplasma.

  9. Novel Temperate Phages of Salmonella enterica subsp. salamae and subsp. diarizonae and Their Activity against Pathogenic S. enterica subsp. enterica Isolates.

    Science.gov (United States)

    Mikalová, Lenka; Bosák, Juraj; Hříbková, Hana; Dědičová, Daniela; Benada, Oldřich; Šmarda, Jan; Šmajs, David

    2017-01-01

    Forty strains of Salmonella enterica (S. enterica) subspecies salamae (II), arizonae (IIIa), diarizonae (IIIb), and houtenae (IV) were isolated from human or environmental samples and tested for bacteriophage production. Production of bacteriophages was observed in 15 S. enterica strains (37.5%) belonging to either the subspecies salamae (8 strains) or diarizonae (7 strains). Activity of phages was tested against 52 pathogenic S. enterica subsp. enterica isolates and showed that phages produced by subsp. salamae had broader activity against pathogenic salmonellae compared to phages from the subsp. diarizonae. All 15 phages were analyzed using PCR amplification of phage-specific regions and 9 different amplification profiles were identified. Five phages (SEN1, SEN4, SEN5, SEN22, and SEN34) were completely sequenced and classified as temperate phages. Phages SEN4 and SEN5 were genetically identical, thus representing a single phage type (i.e. SEN4/5). SEN1 and SEN4/5 fit into the group of P2-like phages, while the SEN22 phage showed sequence relatedness to P22-like phages. Interestingly, while phage SEN34 was genetically distantly related to Lambda-like phages (Siphoviridae), it had the morphology of the Myoviridae family. Based on sequence analysis and electron microscopy, phages SEN1 and SEN4/5 were members of the Myoviridae family and phage SEN22 belonged to the Podoviridae family.

  10. 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.

  11. 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.

  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. 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

  15. 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

  16. 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

  17. CONTINUOUS MEASUREMENT OF THE CYTOPLASMIC PH IN LACTOCOCCUS-LACTIS WITH A FLUORESCENT PH INDICATOR

    NARCIS (Netherlands)

    MOLENAAR, D; ABEE, T; KONINGS, WN

    1991-01-01

    The cytoplasmic pH of Lactococcus lactis was studied with the fluorescent pH indicator 2',7'-bis-(2-carboxyethyl)-5 (and-6)-carboxyfluorescein (BCECF). A novel method was applied for loading bacterial cells with BCECF, which consists of briefly treating a dense cell suspension with acid in the

  18. Quantitative physiology of Lactococcus lactis at extreme low-growth rates

    NARCIS (Netherlands)

    Ercan, O.; Smid, E.J.; Kleerebezem, M.

    2013-01-01

    This paper describes the metabolic adaptation of Lactococcus lactis during the transition from a growing to a non-growing state using retentostat cultivation. Under retentostat cultivation, the specific growth rate decreased from 0.025 h-1 to 0.0001 h-1 in 42 days, while doubling time increased to

  19. The Mode of Replication Is a Major Factor in Segregational Plasmid Instability in Lactococcus lactis

    NARCIS (Netherlands)

    Kiewiet, Rense; Kok, Jan; Seegers, Jos F.M.L.; Venema, Gerard; Bron, Sierd

    1993-01-01

    The effects of the rolling-circle and theta modes of replication on the maintenance of recombinant plasmids in Lactococcus lactis were studied. Heterologous Escherichia coli or bacteriophage λ DNA fragments of various sizes were inserted into vectors based on either the rolling-circle-type plasmid

  20. Carbon catabolite repression and global control of the carbohydrate metabolism in Lactococcus lactis

    NARCIS (Netherlands)

    Luesink, E.J.

    1998-01-01

    In view of the economic importance of fermented dairy products considerable scientific attention has been given to various steps of fermentation processes, including the L-lactate formation of lactic acid bacteria (de Vos, 1996). In particular, the carbohydrate metabolism of L. lactis has

  1. Bacteriophage resistance of a Delta thyA mutant of Lactococcus lactis blocked in DNA replication

    DEFF Research Database (Denmark)

    Pedersen, M.B.; Jensen, Peter Ruhdal; Janzen, T.

    2002-01-01

    The thyA gene, which encodes thymidylate synthase (TS), of Lactococcus lactis CHCC373 was sequenced, including the upstream and downstream regions. We then deleted part of thyA by gene replacement. The resulting strain, MBP71 DeltathyA, was devoid of TS activity, and in media without thymidine...

  2. 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.

  3. Genetics of Lactic Acid Bacteria : Genetics of proteolysis in Lactococcus lactis

    NARCIS (Netherlands)

    Kok, Jan; Buist, Girbe

    2003-01-01

    Genetic and biochemical research over the past 15 years on milk protein degradation by Lactococcus lactis has resulted in a detailed picture of how casein is broken down into its sub-fragments and used for cellular growth. Starting with the action of an extracellular but cell-wall-located

  4. Insertion-Sequence-Mediated Mutations Isolated During Adaptation to Growth and Starvation in Lactococcus lactis.

    NARCIS (Netherlands)

    Visser, de J.A.G.M.; Akkermans, A.D.L.; Hoekstra, R.F.; Vos, de W.M.

    2004-01-01

    We studied the activity of three multicopy insertion sequence (IS) elements in 12 populations of Lactococcus lactis IL1403 that evolved in the laboratory for 1000 generations under various environmental conditions (growth or starvation and shaken or stationary). Using RFLP analysis of single-clone

  5. Transport of Basic Amino Acids by Membrane Vesicles of Lactococcus lactis

    NARCIS (Netherlands)

    Driessen, Arnold J.M.; Leeuwen, Cornelis van; Konings, Wilhelmus

    The uptake of the basic amino acids arginine, ornithine, and lysine was studied in membrane vesicles derived from cells of Lactococcus lactis which were fused with liposomes in which beef heart mitochondrial cytochrome c oxidase was incorporated as a proton motive force (PMF)-generating system. In

  6. 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

  7. Development, molecular characterisation and exploitation of the nisin controlled expression system in Lactococcus lactis

    NARCIS (Netherlands)

    Ruyter, de P.G.G.A.

    1998-01-01

    Lactic acid bacteria are gram-positive bacteria that are widely used in a variety of dairy fermentation processes. Notably, strains of the lactic acid starter bacterium Lactococcus lactis are of great economic importance because of their world-wide use in cheese making.

  8. Immunogenicity of a malaria parasite antigen displayed by Lactococcus lactis in oral immunisations

    NARCIS (Netherlands)

    Ramasamy, R; Yasawardena, S; Zomer, A; Venema, G; Kok, J; Leenhouts, K

    2006-01-01

    A putative protective protein from Plasmodium falciparum merozoites, MSA2, was expressed in two different ways on the cell surface of the Gram-positive food-grade bacterium, Lactococcus lactis. The first display format exploits an LPXTG-type anchoring motif of the lactococcal proteinase PrtP to

  9. Spray drying of starter cultures: Diverse solutions within Lactococcus lactis to improve robustness

    NARCIS (Netherlands)

    Dijkstra, A.R.

    2015-01-01

    This thesis describes the assessment and the possible exploitation of the natural diversity within Lactococcus lactis strains with respect to robustness. Special focus was on survival during heat and oxidative stress, which are both important parameters for optimal performance and survival during

  10. A chloride-inducible gene expression cassette and its use in induced lysis of Lactococcus lactis

    NARCIS (Netherlands)

    Sanders, Jan Willem; Venema, Gerard; Kok, Jan

    1997-01-01

    A chloride-inducible promoter previously isolated from the chromosome of Lactococcus lactis (J. W. Sanders, G. Venema, J. Kok, and K. Leenhouts, Mol. Gen. Genet., in press) was exploited for the inducible expression of homologous and heterologous gens. An expression cassette consisting of the

  11. The Transcriptional and Gene Regulatory Network of Lactococcus lactis MG1363 during Growth in Milk

    DEFF Research Database (Denmark)

    de Jong, Anne; Hansen, Morten Ejby; Kuipers, Oscar P.

    2013-01-01

    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 a...

  12. Characterization of the Lactococcus lactis lactose genes and regulation of their expression

    NARCIS (Netherlands)

    Rooijen, van R.J.

    1993-01-01

    An important trait of the lactic acid bacterium Lactococcus lactis , that is used in industrial dairy fermentations, is the conversion of lactose into lactic acid. The enzymatic steps involved in the breakdown of lactose, that is transported into the cell via a

  13. 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...

  14. 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

    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...

  15. Dependence of Streptococcus lactis Phosphate Transport on Internal Phosphate Concentration and Internal pH

    NARCIS (Netherlands)

    POOLMAN, B; NIJSSEN, RMJ; KONINGS, WN

    1987-01-01

    Uptake of phosphate by Streptococcus lactis ML3 proceeds in the absence of a proton motive force, but requires the synthesis of ATP by either arginine or lactose metabolism. The appearance of free Pi internally in arginine-metabolizing cells corresponded quantitatively with the disappearance of

  16. Cloning, Characterization, Controlled Overexpression, and Inactivation of the Major Tributyrin Esterase Gene of Lactococcus lactis

    NARCIS (Netherlands)

    Fernández, Leonides; Beerthuyzen, Marke M.; Brown, Julie; Siezen, Roland J.; Coolbear, Tim; Holland, Ross; Kuipers, Oscar P.

    2000-01-01

    The gene encoding the major intracellular tributyrin esterase of Lactococcus lactis was cloned using degenerate DNA probes based on 19 known N-terminal amino acid residues of the purified enzyme. The gene, named estA, was sequenced and found to encode a protein of 258 amino acid residues. The

  17. Autolysis of Lactococcus lactis caused by induced overproduction of its major autolysin, AcmA

    NARCIS (Netherlands)

    Buist, Girbe; Karsens, H; Nauta, A; van Sinderen, D; Venema, G; Kok, J

    The optical density of a culture of Lactococcus lactis MG1363 was reduced more than 60% during prolonged stationary phase, Reduction in optical density (autolysis) was almost absent in a culture of an isogenic mutant containing a deletion in the major autolysin gene, acmA. An acmA mutant carrying

  18. ClpE from Lactococcus lactis promotes repression of CtsR-dependent gene expression

    DEFF Research Database (Denmark)

    Varmanen, P.; Vogensen, F.K.; Hammer, Karin

    2003-01-01

    ATPase (ClpE) in Lactococcus lactis is required for such a decrease in expression of a gene negatively regulated by the heat shock regulator (CtsR). Northern blot analysis showed that while a shift to a high temperature in wild-type cells resulted in a temporal increase followed by a decrease...

  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. Molecular characterization and exploitation of the temperate Lactococcus lactis bacteriophage r1t

    NARCIS (Netherlands)

    Nauta, Arjen

    1997-01-01

    When comprehending the scale at wich the Gram-positive lactic acid bacterium Lactococcus lactis is used in the dairy-industry, one can imagine the consequences of fermentation failures. To date, the most serious threat to these large scale fermentation processes. ... Zie Summary

  1. 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

  2. Secreted expression of Leuconostoc mesenteroides glucansucrase in Lactococcus lactis for the production of insoluble glucans

    Science.gov (United States)

    We expressed a glucansucrase, DsrI, from Leuconostoc mesenteroides that catalyzes formation of water-insoluble glucans from sucrose in Lactococcus lactis using a nisin-controlled gene expression system. Production of DsrI was optimized using several different background vectors, signal peptides, str...

  3. Topology of a type I secretion system for bacteriocins of Lactococcus lactis

    NARCIS (Netherlands)

    Franke, Christian Marc

    1998-01-01

    This thesis describes the analysis of a number of aspects of the secretion and muturation machinery of the bacteriocin lactococcin A (LcnA) from Lactococcus lactis, whick is initially synthesized as a precursor protein (preLcnA), containing an N-terminal extension of 20 amino acids (the leader)....

  4. Unity in organisation and regulation of catabolic operons in Lactobacillus plantarum, Lactococcus lactis and Listeria monocytogenes

    NARCIS (Netherlands)

    Andersson, U.; Molenaar, D.; Radstrom, P.; Vos, de W.M.

    2005-01-01

    Global regulatory circuits together with more specific local regulators play a notable role when cells are adapting to environmental changes. Lactococcus lactis is a lactic acid bacterium abundant in nature fermenting most mono- and disaccharides. Comparative genomics analysis of the operons

  5. 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

  6. Overview on sugar metabolism and its control in Lactococcus lactis - The input from in vivo NMR

    NARCIS (Netherlands)

    Neves, AR; Pool, WA; Kok, J; Kuipers, OP; Santos, H; Neves, Ana Rute; Pool, Wietske A.

    The wide application of lactic acid bacteria in the production of fermented foods depends to a great extent on the unique features of sugar metabolism in these organisms. The relative metabolic simplicity and the availability of genetic tools made Lactococcus lactis the organism of choice to gain

  7. Physiological responses of Lactococcus lactis ML3 to alternating conditions of growth and starvation

    NARCIS (Netherlands)

    Kunji, E.R.S.; Ubbink, T.; Matin, A.; Poolman, B.; Konings, W.N.

    Lactococcus lactis species can survive periods of carbohydrate starvation for relatively long periods of time. In the first hours of starvation, however, the maximal glycolytic and arginine deiminase (ADI) pathway activities decline rapidly. The rate of decrease of the pathway activities diminishes

  8. OLIGOPEPTIDES ARE THE MAIN SOURCE OF NITROGEN FOR LACTOCOCCUS-LACTIS DURING GROWTH IN MILK

    NARCIS (Netherlands)

    JUILLARD, [No Value; LEBARS, D; KUNJI, ERS; KONINGS, WN; GRIPON, JC; RICHARD, J

    The consumption of amino acids and peptides was monitored during growth in milk of proteinase-positive (Prt(+)) and -negative (Prt(-)) strains of Lactococcus lactis, The Prt(-) strains showed monophasic exponential growth, while the Prt(+) strains grew in two phases. The first growth phases of the

  9. Arginine metabolism in sugar deprived Lactococcus lactis enhances survival and cellular activity, while supporting flavour production

    NARCIS (Netherlands)

    Brandsma, J.B.; Kraats, van de I.; Abee, T.; Zwietering, M.H.; Meijer, W.C.

    2012-01-01

    Flavour development in cheese is affected by the integrity of Lactococcus lactis cells. Disintegrated cells enhance for instance the enzymatic degradation of casein to free amino acids, while integer cells are needed to produce specific flavour compounds from amino acids. The impact of the cellular

  10. Sugar metabolism, redox balance and oxidative stress response in the respiratory yeast Kluyveromyces lactis.

    Science.gov (United States)

    González-Siso, M Isabel; García-Leiro, Ana; Tarrío, Nuria; Cerdán, M Esperanza

    2009-08-30

    A lot of studies have been carried out on Saccharomyces cerevisiae, an yeast with a predominant fermentative metabolism under aerobic conditions, which allows exploring the complex response induced by oxidative stress. S. cerevisiae is considered a eukaryote model for these studies. We propose Kluyveromyces lactis as a good alternative model to analyse variants in the oxidative stress response, since the respiratory metabolism in this yeast is predominant under aerobic conditions and it shows other important differences with S. cerevisiae in catabolic repression and carbohydrate utilization. The knowledge of oxidative stress response in K. lactis is still a developing field. In this article, we summarize the state of the art derived from experimental approaches and we provide a global vision on the characteristics of the putative K. lactis components of the oxidative stress response pathway, inferred from their sequence homology with the S. cerevisiae counterparts. Since K. lactis is also a well-established alternative host for industrial production of native enzymes and heterologous proteins, relevant differences in the oxidative stress response pathway and their potential in biotechnological uses of this yeast are also reviewed.

  11. Sugar metabolism, redox balance and oxidative stress response in the respiratory yeast Kluyveromyces lactis

    Directory of Open Access Journals (Sweden)

    Cerdán M Esperanza

    2009-08-01

    Full Text Available Abstract A lot of studies have been carried out on Saccharomyces cerevisiae, an yeast with a predominant fermentative metabolism under aerobic conditions, which allows exploring the complex response induced by oxidative stress. S. cerevisiae is considered a eukaryote model for these studies. We propose Kluyveromyces lactis as a good alternative model to analyse variants in the oxidative stress response, since the respiratory metabolism in this yeast is predominant under aerobic conditions and it shows other important differences with S. cerevisiae in catabolic repression and carbohydrate utilization. The knowledge of oxidative stress response in K. lactis is still a developing field. In this article, we summarize the state of the art derived from experimental approaches and we provide a global vision on the characteristics of the putative K. lactis components of the oxidative stress response pathway, inferred from their sequence homology with the S. cerevisiae counterparts. Since K. lactis is also a well-established alternative host for industrial production of native enzymes and heterologous proteins, relevant differences in the oxidative stress response pathway and their potential in biotechnological uses of this yeast are also reviewed.

  12. Stimulation of acetoin production in metabolically engineered Lactococcus lactis by increasing ATP demand

    DEFF Research Database (Denmark)

    Liu, Jianming; Kandasamy, Vijayalakshmi; Würtz, Anders

    2016-01-01

    into a Lactococcus lactis strain engineered into producing acetoin, we show that production titer and yield both can be increased. At high F1-ATPase expression level, the acetoin production yield could be increased by 10 %; however, because of the negative effect that the F1-ATPase had on biomass yield and growth...

  13. CLONING AND MOLECULAR ANALYSIS OF THE DIHYDROFOLATE-REDUCTASE GENE FROM LACTOCOCCUS-LACTIS

    NARCIS (Netherlands)

    LESZCZYNSKA, K; BOLHUIS, A; LEENHOUTS, K; VENEMA, G; CEGLOWSKI, P

    The Lactococcus lactis gene encoding trimethoprim resistance has been cloned and expressed in Escherichia coli and Bacillus subtilis. Several lines of evidence indicate that the cloned gene encodes dihydrofolate reductase (DHFR). (i) It fully complements the fol ''null'' mutation in E. coli. (ii)

  14. Stress Response in Lactococcus lactis : Cloning, Expression Analysis, and Mutation of the Lactococcal Superoxide Dismutase Gene

    NARCIS (Netherlands)

    Sanders, Jan Willem; Leenhouts, Kees J.; Haandrikman, Alfred J.; Venema, Gerard; Kok, Jan

    In an analysis of the stress response of Lactococcus lactis, three proteins that were induced under low pH culture conditions were detected. One of these was identified as the lactococcal superoxide dismutase (SodA) by N-terminal amino acid sequence analysis. The gene encoding this protein,

  15. Phosphoglycerate Mutase Is a Highly Efficient Enzyme without Flux Control in Lactococcus lactis

    DEFF Research Database (Denmark)

    Solem, Christian; Petranovic, D.; Købmann, Brian

    2010-01-01

    The glycolytic enzyme phosphoglycerate mutase (PGM), which catalyzes the conversion of 3-phosphoglycerate to 2-phosphoglycerate, was examined in Lactococcus lactis with respect to its function, kinetics and glycolytic flux control. A library of strains with PGM activities ranging between 15-465% ...

  16. 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 (? = 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

  17. Genome-Wide Transcriptional Responses to Carbon Starvation in Nongrowing Lactococcus lactis

    NARCIS (Netherlands)

    Ercan, O.; Wels, M.W.; 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 (mu = 0.0001 h(-1)) obtained by extended retentostat cultivation were exposed to starvation by termination of the medium supply for 24 h, followed

  18. A System To Generate Chromosomal Mutations in Lactococcus lactis Which Allows Fast Analysis of Targeted Genes

    NARCIS (Netherlands)

    Law, Jean; Buist, Girbe; Haandrikman, Alfred; Kok, Jan; Venema, Gerhardus; Leenhouts, Kees

    1995-01-01

    A system for generating chromosomal insertions in lactococci is described. It is based on the conditional replication of lactococcal pWV01-derived Ori+ RepA- vector pORI19, containing lacZα and the multiple cloning site of pUC19. Chromosomal AluI fragments of Lactococcus lactis were cloned in pORI19

  19. An exoproteome approach to monitor safety of a cheese-isolated Lactococcus lactis

    DEFF Research Database (Denmark)

    Genovese, Federica; Coïsson, Jean Daniel; Majumder, Avishek

    2013-01-01

    The safety of the cheese-isolated and potential starter Lactococcus lactis 11D was explored by means of an extracellular proteomic study. A preliminary analysis showed good caseification/proteolytic behavior of the strain, absence of production of biogenic amines and good survival at acidic p...

  20. Relation of Growth of Streptococcus lactis and Streptococcus cremoris to Amino Acid Transport

    NARCIS (Netherlands)

    Poolman, Bert; Konings, Wil N.

    The maximum specific growth rate of Streptococcus lactis and Streptococcus cremoris on synthetic medium containing glutamate but no glutamine decreases rapidly above pH 7. Growth of these organisms is extended to pH values in excess of 8 in the presence of glutamine. These results can be explained

  1. Isomer-specific consumption of galactooligosaccharides by bifidobacterial species

    Science.gov (United States)

    Tsui, Man Ki; Mills, David A.; Lebrilla, Carlito B.

    2014-01-01

    Prebiotics are non-digestible substrates that stimulate the growth of beneficial microbes in the human intestine. Galactooligosaccharides (GOS) are food ingredients that possess prebiotic properties, in particular, promoting the growth of bifidobacteria in situ. However precise mechanistic details of GOS consumption by bifidobacteria remains poorly understood. Because GOS are mixtures of polymers of different lengths and linkages, there is interest to determine which specific structures provide prebiotic effects in order to potentially create better supplements. We here present a method comprising porous graphitic carbon separation, isotopic labeling and mass spectrometry analysis for the structure specific analysis of GOS isomers and their bacterial consumption rate. Using this strategy, the differential bacterial consumption of GOS by the bifidobacteria species B. longum subsp. infantis, B. animalis subsp. lactis and B. adolescentis was determined, indicating that the use of specific GOS isomers in infant formula may provide enrichment of distinct species. PMID:24313277

  2. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on the substantiation of health claims related to the substantiation of health claims related to various microorganisms and changes in bowel function, and digestion and absorption of nutrients (ID 960, 961, 967, 969, 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

    to the claimed effects. No human studies which investigated the effects of the food constituents on appropriate measures of the claimed effects were provided. On the basis of the data presented, the Panel concludes that a cause and effect relationship has not been established between the consumption of the food...... 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...... for the health claims related to changes in bowel function and decreasing potentially pathogenic gastro-intestinal microorganisms included studies which assessed the effects of food constituents other than the food constituents which are the subject of the claims and/or investigated health outcomes unrelated...

  3. Molecular identification of Streptococcus equi subsp. equi and Streptococcus equi subsp. zooepidemicus in nasal swabs samples from horses suffering respiratory infections in Iran.

    Science.gov (United States)

    Jannatabadi, A A; Mohammadi, G R; Rad, M; Maleki, M

    2008-02-01

    The objective of this study was to evaluate the existence of Streptococcus equi subsp. equi and Streptococcus equi subsp. zooepidemicus as probable agents associated with naturally occurring infection of the equine upper respiratory disease in Mashhad area. Nasal swabs samples from thirty horses with upper respiratory tract infections were collected. The bacteria isolated and identified were Streptococcus equi subsp. equi (1 isolate), Streptococcus equi subsp. zooepidemicus (25 isolates), Pasteurella sp. (11 isolates), Staphylococcus sp. (17 isolates), Bacillus sp. (4 isolates), Pseudomonas sp. (4 isolates), Proteus sp. (1 isolate), Neisseria sp. (1 isolate) and E. coli (1 isolate). All 25 isolates of Streptococcus equi subsp. zooepidemicus and the isolate of Streptococcus equi subsp. equi were characterized by biochemical tests and molecular techniques. For molecular identification of the subspecies S. equi and S. zooepidemicus two genomic region SeM and sodA were amplified. This study is the first report of molecular identification of Streptococcus equi subsp. equi and Streptococcus equi subsp. zooepidemicus in Iran.

  4. Chromosomal Diversity in Lactococcus lactis and the Origin of Dairy Starter Cultures

    Science.gov (United States)

    Kelly, William J.; Ward, Lawrence J. H.; Leahy, Sinead C.

    2010-01-01

    A large collection of Lactococcus lactis strains, including wild-type isolates and dairy starter cultures, were screened on the basis of their phenotype and the macrorestriction patterns produced from pulsed-field gel electrophoresis (PFGE) analysis of SmaI digests of genomic DNA. Three groups of dairy starter cultures, used for different purposes in the dairy industry, and a fourth group made up of strains isolated from the environment were selected for analysis of their chromosomal diversity using the endonuclease I-CeuI. Chromosome architecture was largely conserved with each strain having six copies of the rRNA genes, and the chromosome size of individual strains ranged between 2,240 and 2,688 kb. The origin of L. lactis strains showed the greatest correlation with chromosome size, and dairy strains, particularly those with the cremoris phenotype, had smaller chromosomes than wild-type strains. Overall, this study, coupled with analysis of the sequenced L. lactis genomes, provides evidence that defined strain dairy starter cultures have arisen from plant L. lactis strains. Adaptation of these strains to the dairy environment has involved loss of functions resulting in smaller chromosomes and acquisition of genes (usually plasmid associated) that facilitate growth in milk. We conclude that dairy starter cultures generally and the industrially used cremoris and diacetylactis phenotype strains in particular comprise a specialized group of L. lactis strains that have been selected to become an essential component of industrial processes and have evolved accordingly, so that they are no longer fit to survive outside the dairy environment. PMID:20847124

  5. 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.

  6. Development of a high efficient biocatalyst by oriented covalent immobilization of a novel recombinant 2'-N-deoxyribosyltransferase from Lactobacillus animalis.

    Science.gov (United States)

    Méndez, Mariana B; Rivero, Cintia W; López-Gallego, Fernando; Guisán, José M; Trelles, Jorge A

    2018-03-20

    The 2'-N-deoxyribosyltransferases [NDT; EC 2.4.2.6] are a group of enzymes widely used as biocatalysts for nucleoside biosynthesis. In this work, the molecular cloning, expression and purification of a novel NDT from Lactobacillus animalis (LaNDT) have been reported. On the other hand, biocatalyst stability has been significantly enhanced by multipoint covalent immobilization using a hetero-functional support activated with nickel-chelates and glyoxyl groups. The immobilized enzyme could be reused for more than 300 h and stored during almost 3 months without activity loss. Besides, the obtained derivative (Ni 2+ -Gx-LaNDT) was able to biosynthesize 88 mg floxuridine/g biocatalyst after 1 h of reaction. In this work, a green bioprocess by employing an environmentally friendly methodology was developed, which allowed the obtaining of a compound with proven anti-tumor activity. Therefore, the obtained enzymatic biocatalyst meets the requirements of high activity, stability, and short reaction times needed for low-cost production in a future preparative application. Copyright © 2018. Published by Elsevier B.V.

  7. Persistence of probiotic strains in the gastrointestinal tract when administered as capsules, yoghurt, or cheese.

    Science.gov (United States)

    Saxelin, Maija; Lassig, Anna; Karjalainen, Heli; Tynkkynen, Soile; Surakka, Anu; Vapaatalo, Heikki; Järvenpää, Salme; Korpela, Riitta; Mutanen, Marja; Hatakka, Katja

    2010-12-15

    Most clinical studies of probiotics use freeze-dried, powdered bacteria or bacteria packed in capsules. However, probiotics are commercially available in various food matrices, which may affect their persistence in the gastrointestinal tract. The objective of the study was to compare oral and faecal recovery during and after administration of a combination of Lactobacillus rhamnosus GG and LC705, Propionibacterium freudenreichii subsp. shermanii JS, and Bifidobacterium animalis subsp. lactis Bb12 as capsules, yoghurt, or cheese. This randomized, parallel-group, open-label trial (n=36) included a 4-week run-in, 2-week intervention, and 3-week follow-up period. Participants consumed 10(10)cfu/day of probiotic combination and provided saliva and faecal samples before, during, and after the intervention. Strain-specific real-time PCR was used to quantify the strains. L. rhamnosus GG was the only probiotic strain regularly recovered in saliva samples. During the intervention period it was recovered in the saliva of 88% of the volunteers at least once. No difference was found between the yoghurt and cheese groups. At the end of the intervention, L. rhamnosus GG and LC705 counts were high in faecal samples of all product groups (8.08 and 8.67log(10) genome copies/g, respectively). There was no matrix effect on strain quantity in faeces or the recovery time after ceasing the intervention. For P. freudenreichii subsp. shermanii JS and B. animalis subsp. lactis Bb12, a matrix effect was found at the end of the intervention (Pprobiotics in yoghurt matrix is highly suitable for studying potential health benefits and capsules provide a comparable means of administration when the viability of the strain in the capsule product is confirmed. Copyright © 2010 Elsevier B.V. All rights reserved.

  8. Powerful methods to establish chromosomal markers in Lactococcus lactis: an analysis of pyrimidine salvage pathway mutants obtained by positive selections

    DEFF Research Database (Denmark)

    Martinussen, Jan; Hammer, Karin

    1995-01-01

    Using different 5-fluoropyrimidine analogues, positive selection procedures for obtaining mutants blocked in pyrimidine and purine salvage genes of Lactococcus lactis were established. Strains lacking the following enzyme activities due to mutations in the corresponding genes were isolated: uracil...

  9. Reconstitution of the Leucine Transport System of Lactococcus lactis into Liposomes Composed of Membrane-Spanning Lipids from Sulfolobus acidocaldarius

    NARCIS (Netherlands)

    in t Veld, Geertruida; Elferink, Maria; Driessen, Arnold J.M.; Konings, Wilhelmus

    1992-01-01

    The effect of bipolar tetraether lipids, extracted from the thermophilic archaebacterium Sulfolobus acidocaldarius, on the branched-chain amino acid transport system of the mesophilic bacterium Lactococcus lactis was investigated. Liposomes were prepared from mixtures of monolayer lipids and the

  10. Development and Diversity of Lactococcus lactis and Leuconostoc Bacteriophages in Dairies Using Undefined Mesophilic DL-Starter Cultures

    DEFF Research Database (Denmark)

    Muhammed, Musemma Kedir

    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...

  11. 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...

  12. Reduced binding of the endolysin LysTP712 to Lactococcus lactis ΔftsH contributes to phage resistance

    Directory of Open Access Journals (Sweden)

    CLARA eROCES

    2016-02-01

    Full Text Available Absence of the membrane protease FtsH in Lactococcus lactis hinders release of the bacteriophage TP712. In this work we have analysed the mechanism responsible for the non-lytic phenotype of L. lactis ΔftsH after phage infection. The lytic cassette of TP712 contains a putative antiholin-pinholin system and a modular endolysin (LysTP712. Inducible expression of the holin gene demonstrated the presence of a dual start motif which is functional in both wildtype and L. lactis ΔftsH cells. Moreover, simulating holin activity with ionophores accelerated lysis of wildtype cells but not L. lactis ΔftsH cells, suggesting inhibition of the endolysin rather than a role of FtsH in holin activation. However, zymograms revealed the synthesis of an active endolysin in both wildtype and L. lactis ΔftsH TP712 lysogens. A reporter protein was generated by fusing the cell wall binding domain of LysTP712 to the fluorescent mCherry protein. Binding of this reporter protein took place at the septa of both wildtype and L. lactis ΔftsH cells as shown by fluorescence microscopy. Nonetheless, fluorescence spectroscopy demonstrated that mutant cells bound 40 % less protein. In conclusion, the non-lytic phenotype of L. lactis ΔftsH is not due to direct action of the FtsH protease on the phage lytic proteins but rather to a putative function of FtsH in modulating the architecture of the L. lactis cell envelope that contributes to a lower affinity of the phage endolysin to its substrate and, likely to its catalytic activity.

  13. Reduced Binding of the Endolysin LysTP712 to Lactococcus lactis ΔftsH Contributes to Phage Resistance.

    Science.gov (United States)

    Roces, Clara; Campelo, Ana B; Escobedo, Susana; Wegmann, Udo; García, Pilar; Rodríguez, Ana; Martínez, Beatriz

    2016-01-01

    Absence of the membrane protease FtsH in Lactococcus lactis hinders release of the bacteriophage TP712. In this work we have analyzed the mechanism responsible for the non-lytic phenotype of L. lactis ΔftsH after phage infection. The lytic cassette of TP712 contains a putative antiholin-pinholin system and a modular endolysin (LysTP712). Inducible expression of the holin gene demonstrated the presence of a dual start motif which is functional in both wildtype and L. lactis ΔftsH cells. Moreover, simulating holin activity with ionophores accelerated lysis of wildtype cells but not L. lactis ΔftsH cells, suggesting inhibition of the endolysin rather than a role of FtsH in holin activation. However, zymograms revealed the synthesis of an active endolysin in both wildtype and L. lactis ΔftsH TP712 lysogens. A reporter protein was generated by fusing the cell wall binding domain of LysTP712 to the fluorescent mCherry protein. Binding of this reporter protein took place at the septa of both wildtype and L. lactis ΔftsH cells as shown by fluorescence microscopy. Nonetheless, fluorescence spectroscopy demonstrated that mutant cells bound 40% less protein. In conclusion, the non-lytic phenotype of L. lactis ΔftsH is not due to direct action of the FtsH protease on the phage lytic proteins but rather to a putative function of FtsH in modulating the architecture of the L. lactis cell envelope that results in a lower affinity of the phage endolysin to its substrate.

  14. 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.

  15. 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

  16. 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)

  17. Actinobacillus equuli subsp. equuli associated with equine valvular endocarditis

    DEFF Research Database (Denmark)

    Aalbæk, Bent; Østergaard, Stine; Buhl, Rikke

    2007-01-01

    Microbiological and pathological data from a case of equine valvular endocarditis are reported. Limited information is available on the pathogenic potential of equine Actinobacillus species as several strains originate from apparently healthy horses. After the establishment of two subspecies within...... this species, this seems to be the first report of an etiological association between A. equuli subsp. equuli and equine endocarditis. Furthermore, new information on some phenotypical characteristics of this subspecies are reported, compared to previous findings...

  18. Russian isolates enlarge the known geographic diversity of Francisella tularensis subsp. mediasiatica.

    Directory of Open Access Journals (Sweden)

    Vitalii Timofeev

    Full Text Available Francisella tularensis, a small Gram-negative bacterium, is capable of infecting a wide range of animals, including humans, and causes a plague-like disease called tularemia-a highly contagious disease with a high mortality rate. Because of these characteristics, F. tularensis is considered a potential agent of biological terrorism. Currently, F. tularensis is divided into four subspecies, which differ in their virulence and geographic distribution. Two of them, subsp. tularensis (primarily found in North America and subsp. holarctica (widespread across the Northern Hemisphere, are responsible for tularemia in humans. Subsp. novicida is almost avirulent in humans. The fourth subspecies, subsp. mediasiatica, is the least studied because of its limited distribution and impact in human health. It is found only in sparsely populated regions of Central Asia. In this report, we describe the first focus of naturally circulating F. tularensis subsp. mediasiatica in Russia. We isolated and characterized 18 strains of this subspecies in the Altai region. All strains were highly virulent in mice. The virulence of subsp. mediasiatica in a vaccinated mouse model is intermediate between that of subsp. tularensis and subsp. holarctica. Based on a multiple-locus variable number tandem repeat analysis (MLVA, we show that the Altaic population of F. tularensis subsp. mediasiatica is genetically distinct from the classical Central Asian population, and probably is endemic to Southern Siberia. We propose to subdivide the mediasiatica subspecies into three phylogeographic groups, M.I, M.II and M.III.

  19. Colonization patterns of an mCherry-tagged Pectobacterium carotovorum subsp. brasiliense strain in potato plants.

    Science.gov (United States)

    Kubheka, Gugulethu C; Coutinho, Teresa A; Moleleki, Ntsane; Moleleki, Lucy N

    2013-12-01

    Pectobacterium carotovorum subsp. brasiliense is a newly identified member of the potato soft rot enterobacteriaceae. The pathogenesis of this pathogen is still poorly understood. In this study, an mCherry-P. carotovorum subsp. brasiliense-tagged strain was generated to study P. carotovorum subsp. brasiliense-potato plant interactions. Prior to use, the tagged strain was evaluated for in vitro growth, plasmid stability, and virulence on potato tubers and shown to be similar to the wild type. Four potato cultivars were evaluated for stem-based resistance against P. carotovorum subsp. brasiliense. Confocal laser-scanning microscopy and in vitro viable cell counts showed that P. carotovorum subsp. brasiliense is able to penetrate roots of a susceptible potato cultivar as early as 12 h postinoculation and migrate upward into aerial stem parts. Due to the phenotypic differences observed between tolerant and susceptible cultivars, a comparison of P. carotovorum subsp. brasiliense colonization patterns in these cultivars was undertaken. In the susceptible cultivar, P. carotovorum subsp. brasiliense cells colonized the xylem tissue, forming "biofilm-like" aggregates that led to occlusion of some of the vessels. In contrast, in the tolerant cultivar, P. carotovorum subsp. brasiliense appeared as free-swimming planktonic cells with no specific tissue localization. This suggests that there are resistance mechanisms in the tolerant cultivar that limit aggregation of P. carotovorum subsp. brasiliense in planta and, hence, the lack of symptom development in this cultivar.

  20. Bacillus amyloliquefaciens SUBSP. plantarum PROBIOTIC STRAINS AS PROTEASE PRODUCERS

    Directory of Open Access Journals (Sweden)

    E. V. Маtseliukh

    2015-04-01

    Full Text Available Proteases from probiotic strains of the genus Bacillus, just like the antibiotics, bacteriocins and other hydrolytic enzymes, are one of the main factors that determine their biological activity. The aim of this work was to study the synthesis and biochemical properties of proteases from two strains Bacillus amyloliquefaciens subsp. plantarum UCM B-5139 and UCM B-5140 that included in the probiotic Endosporin. The cultivation of strains was carried out in flasks under rotating for two days. The influence of physico-chemical parameters of the reaction medium on proteolytic activity was studied on partially purified protease preparations. Lytic activity was determined by turbidimetric method. On the second day of cultivation B. amyloliquefaciens subsp. plantarum UCM В-5139 and UCM В-5140 synthesized the metal-dependent peptidase and serine protease, respectively. The optimum conditions of their action were the following: temperature 37–40 °C and pH 6.5–7.0. Isolated proteases are able to lyse the living cells of Staphylococcus aureus and Candida albicans. Thus we demonstrated that B. amyloliquefaciens subsp. plantarum UCM B-5140 and UCM B-5139, included in the probiotic veterinary preparation Endosporin, produced proteolytic enzymes that hydrolyze the native insoluble proteins (elastin, fibrin and collagen. These enzymes belong to the group of neutral metal-dependent and serine proteases. They are active under physiological conditions against gram-positive bacteria and yeasts. The application of these proteases in biotechnology is considered.