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Sample records for bacteriocins

  1. Using Bacteriocins in Milk and Dairy Products

    Directory of Open Access Journals (Sweden)

    Evrim Güneş Altuntaş

    2010-01-01

    Full Text Available Bacteriocins produced by bacteria are ribosomally synthesed and antimicrobial peptides. Lots of strains of bacteria can produce bacteriocin. There are lots of researchs on using bacteriocins produced by lactic acid bacteria (LAB which are known as safe (GRAS in foods. With this respect bacteriocin experiments have been generally in meat and dairy products where can become spoilage easily. It is allowed to use nisin in cheese a dairy product, and with cheese the experiments about using nisin, pediocin, lacticin, variacin etc. are going on the other dairy products. In this review some experiments on using bacteriocins and their results on milk and dairy products are reported.

  2. Identification of Multiple Bacteriocins in Enterococcus spp. Using an Enterococcus-Specific Bacteriocin PCR Array

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    Chris Henning

    2015-02-01

    Full Text Available Twenty-two bacteriocin-producing Enterococcus isolates obtained from food and animal sources, and demonstrating activity against Listeria monocytogenes, were screened for bacteriocin-related genes using a bacteriocin PCR array based on known enterococcal bacteriocin gene sequences in the NCBI GenBank database. The 22 bacteriocin-positive (Bac+ enterococci included En. durans (1, En. faecalis (4, En. faecium (12, En. hirae (3, and En. thailandicus (2. Enterocin A (entA, enterocins mr10A and mr10B (mr10AB, and bacteriocin T8 (bacA were the most commonly found structural genes in order of decreasing prevalence. Forty-five bacteriocin genes were identified within the 22 Bac+ isolates, each containing at least one of the screened structural genes. Of the 22 Bac+ isolates, 15 possessed two bacteriocin genes, seven isolates contained three different bacteriocins, and three isolates contained as many as four different bacteriocin genes. These results may explain the high degree of bactericidal activity observed with various Bac+ Enterococcus spp. Antimicrobial activity against wild-type L. monocytogenes and a bacteriocin-resistant variant demonstrated bacteriocins having different modes-of-action. Mixtures of bacteriocins, especially those with different modes-of-action and having activity against foodborne pathogens, such as L. monocytogenes, may play a promising role in the preservation of food.

  3. Natural and Heterologous Production of Bacteriocins

    Science.gov (United States)

    Cintas, Luis M.; Herranz, Carmen; Hernández, Pablo E.

    Bacteriocins are ribosomally synthesized antimicrobial peptides produced by bacteria, and their use as natural and nontoxic food preservatives has been the source of considerable interest for the research community. In addition, bacteriocins have been investigated for their potential use in human and veterinary applications and in the animal production field. In the native bacterial strain, most bacteriocins are synthesized as biologically inactive precursors, with N-terminal extensions, that are cleaved concomitantly during export of the bacteriocin by dedicated ABC transporters, or the general secretory pathway (GSP) or Sec-dependent pathway. However, a few bacteriocins are synthesized without an N-terminal extension, and others are circularized through a head-to-tail peptide bond, complicating the elucidation of their processing and transport across the cytoplasmic membrane. The high cost of synthetic bacteriocin synthesis and their low yields from many natural producers recommends the exploration of recombinant microbial systems for the heterologous production of bacteriocins. Other advantages of such systems include production of bacteriocins in safer hosts, increased bacteriocin production, control of bacteriocin gene expression, production of food ingredients with antimicrobial activity, construction of multibacteriocinogenic strains with a wider antagonistic spectrum, a better adaptation of the selected hosts to food environments, and providing antagonistic properties to lactic acid bacteria (LAB) used as starter, protective, or probiotic cultures. The recombinant production of bacteriocins mostly relies on the use of expression vectors that replicate in Gram-negative bacteria, Gram-positive bacteria, and yeasts, whereas the production of bacteriocins in heterologous LAB hosts may be essentially based on the expression of native biosynthetic genes, by exchanging or replacing leader peptides and/or dedicated processing and secretion systems (ABC transporters

  4. LAB bacteriocin applications in the last decade

    OpenAIRE

    Ma. del Rocío López-Cuellar; Adriana-Inés Rodríguez-Hernández; Norberto Chavarría-Hernández

    2016-01-01

    In the early 2000s, the expectations about bacteriocins produced by lactic acid bacteria (LABs) were aimed at food applications. However, the effectiveness of bacteriocins against undesirable micro-organisms opened endless possibilities for innovative research. In the present review, we collected a database including 429 published papers and 245 granted patents (from 2004 to 2015). Based on bibliometric analysis, the progress of bacteriocin research in the last 11 years was discussed in detai...

  5. Bacteriocin producers from traditional food products

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    Thonart P.

    2007-01-01

    Full Text Available A total of 220 strains of LAB isolated from 32 samples of traditional fermented food from Senegal were screened for bacteriocin production. Two bacteriocin producers, Lactococcus lactis subsp. lactis and Enterococcus faecium, were identified from 12 bacteriocin-producing isolates on the basis of phenotypic analyses and 16S rDNA sequence. Both bacteriocins produced by new isolates show antimicrobial activity against Listeria monocytogenes and Bacillus coagulans whereas only that produced by Lactococcus lactis has an activity against Bacillus cereus. Bacteriocin-producing Lactococcus lactis strains were found in a variety of traditional foods indicating a high potential of growth of this strain in variable ecological complex environment. Partial 16S rDNA of the two bacteriocin producers obtained in this study has been registered to Genbank databases under the accession number AY971748 for Lactococcus lactis subsp. lactis (named CWBI-B1410 and AY971749 for Enterococcus faecium (named CWBI-B1411. The new bacteriocin-producing Lactococcus lactis subsp. lactis strain has been selected for identification and application of the bacteriocin to food preservation.

  6. Lactobacillus acidophilus bacteriocin, from production to their ...

    African Journals Online (AJOL)

    USER

    2010-05-17

    May 17, 2010 ... Antimicrobial proteinaceous compounds such as bacteriocins or bacteriocin-like compounds produced by Lactobacillus acidophilus are largely known and have been found to have potent antimicrobial activities toward closely related bacteria and undesirable harmful microorganisms. They are useful in.

  7. Bacteriocins: New generation of antimicrobial peptides

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    P. Motahari

    2017-06-01

    Full Text Available Antibiotics are used as a first-choice to inhibit microbial growth since the discovery in the first half of the 19th century. Nevertheless, the widespread use of antibiotics has resulted in the emergence of antibiotic-resistant strains that is one of our century problems. Concerns about antibiotic resistant is so serious which huge budget is allocated for discovery of alternative drugs in many countries. Bacteriocin is one of these compounds which was first discovered in 1925, released into the medium by E. coli. Bacteriocins are antimicrobial peptides or proteins ribosomally synthesized by many bacterial species. The use of this antimicrobial molecules in food industry obviate consumers need to safe food with least interference of chemical substances. Nisin, the most well-known bacteriocin, is the first bacteriocin found its way to food industry. Despite the widespread application of bacteriocins, resistance is seen in some species. Although it’s exact mechanism is not clear. So according to the today’s world need to find effective methods to control pathogens, studies of bacteriocins as a substitute for antibiotics are so important. The present review has studied the structure and activity of five classes of bacteriocins from gene to function in gram positive bacteria.

  8. Bacteriocins From Lactic Acid Bacteria: Interest For Food Products Biopreservation

    OpenAIRE

    Dortu, C.; Thonart, Philippe

    2009-01-01

    Bacteriocins from lactic acid bacteria: interest for food products biopreservation. Bacteriocins from lactic acid bacteria are low molecular weight antimicrobial peptides. They have inhibitory activity against the bacteria that are closed related to the producer strains and a narrow inhibitory spectrum. Nevertheless, most of them have activity against some food-born pathogenic bacteria as Listeria monocytogenes. The application of bacteriocins or bacteriocin producing lactic acid bacteria in ...

  9. Bacteriocins: Novel Solutions to Age Old Spore-Related Problems?

    OpenAIRE

    Kevin eEgan; Des eField; Mary Clare Rea; Mary Clare Rea; R Paul Ross; R Paul Ross; Colin eHill; Colin eHill; Paul David Cotter; Paul David Cotter

    2016-01-01

    Bacteriocins are ribosomally synthesized antimicrobial peptides produced by bacteria, which have the ability to kill or inhibit other bacteria. Many bacteriocins are produced by food grade lactic acid bacteria (LAB). Indeed, the prototypic bacteriocin, nisin, is produced by Lactococcus lactis, and is licensed in over 50 countries. With consumers becoming more concerned about the levels of chemical preservatives present in food, bacteriocins offer an alternative, more natural, approach, while ...

  10. Bacteriocins: Novel Solutions to Age Old Spore-Related Problems?

    OpenAIRE

    Egan, Kevin; Field, Des; Rea, Mary C.; Ross, R. Paul; Hill, Colin; Cotter, Paul D.

    2016-01-01

    Bacteriocins are ribosomally synthesized antimicrobial peptides produced by bacteria, which have the ability to kill or inhibit other bacteria. Many bacteriocins are produced by food grade lactic acid bacteria (LAB). Indeed, the prototypic bacteriocin, nisin, is produced by Lactococcus lactis, and is licensed in over 50 countries. With consumers becoming more concerned about the levels of chemical preservatives present in food, bacteriocins offer an alternative, more natural approach, while e...

  11. Selection and fitness in bacteriocin-producing bacteria.

    OpenAIRE

    Dykes, G A; Hastings, J W

    1997-01-01

    Bacteriocins are proteinaceous anticompetitor molecules produced by bacteria against closely related species. A number of theoretical models have been used to explain experimental data that indicate high polymorphisms among bacteriocins and a frequency-dependent nature of selection for bacteriocin-producing strains. The majority of these experimental data were, however, obtained from investigations into the colicin group of bacteriocins produced by Gram-negative bacteria. The conclusions draw...

  12. Class IIa Bacteriocins: Diversity and New Developments

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    Yanhua Cui

    2012-12-01

    Full Text Available Class IIa bacteriocins are heat-stable, unmodified peptides with a conserved amino acids sequence YGNGV on their N-terminal domains, and have received much attention due to their generally recognized as safe (GRAS status, their high biological activity, and their excellent heat stability. They are promising and attractive agents that could function as biopreservatives in the food industry. This review summarizes the new developments in the area of class IIa bacteriocins and aims to provide uptodate information that can be used in designing future research.

  13. Improvement of Bacillus thuringiensis bacteriocin production through culture conditions optimization.

    Science.gov (United States)

    Kamoun, Fakher; Zouari, Nabil; Saadaoui, Imen; Jaoua, Samir

    2009-01-01

    BUPM4 is a Bacillus thuringiensis subsp. kurstaki strain, isolated from Tunisian soil, producing an original bacteriocin named Bacthuricin F4. The optimization of the latter production conditions was carried out under several physicochemical conditions. It was found that the highest bacteriocin activity was reached at low aeration while bacteriocin synthesis yields were strongly reduced at higher ones. A balance between growth and bacteriocin synthesis, both highly dependent on aeration, was taken into account for the overproduction of bacteriocin. Both glucose and glycerol were shown to be necessary for Bacthuricin F4 maximal synthesis. In addition, the optimal carbon/nitrogen ratio for bacteriocin production is 9. In such optimal conditions, more than 4-fold greater bacteriocin production was obtained than when using TSB medium.

  14. bacteriocin activity of lactobacilli: characterization and optimization ...

    African Journals Online (AJOL)

    Jude Adeleke

    Lactobacillus plantarum F1 and L. brevis OG1 isolated from Nigerian fermented food products, produced bacteriocins that had broad spectrum of inhibition against both pathogenic, food spoilage organisms and various lactic acid bacteria. The test organisms exhibited activities of 6400 and 3200. AU/ml respectively against ...

  15. Characterization of bacteriocin produced by Lactobacillus plantarum ...

    African Journals Online (AJOL)

    Lactobacillus plantarum F1 and L. brevis OG1 isolated from Nigerian fermented food products, produced bacteriocins that had broad spectrum of inhibition against both pathogenic, food spoilage organisms and various lactic acid bacteria. The test organisms exhibited activities of 6400 and 3200 AU/ml respectively against ...

  16. LAB bacteriocin applications in the last decade

    Directory of Open Access Journals (Sweden)

    Ma. del Rocío López-Cuellar

    2016-11-01

    Full Text Available In the early 2000s, the expectations about bacteriocins produced by lactic acid bacteria (LABs were aimed at food applications. However, the effectiveness of bacteriocins against undesirable micro-organisms opened endless possibilities for innovative research. In the present review, we collected a database including 429 published papers and 245 granted patents (from 2004 to 2015. Based on bibliometric analysis, the progress of bacteriocin research in the last 11 years was discussed in detail. It was found that 164 patents were granted in 2010–2015, which is equivalent to 60% in comparison with previous years (i.e. only 81 patents were granted in 2004–2009. Currently, the research on bacteriocins is still gaining importance. In the realm of therapeutic strategies, about a 37% of the published research was focused on biomedical applications in the last decade. This vein of research is currently seeking for alternative solutions to problems such as cancer, systemic infections, oral-care, vaginal infections, contraception and skincare. On the other hand, food preservation, bio-nanomaterial and veterinary applications represent 29%, 25% and 9%, respectively. All this technology is being applied and will surely grow in the future, since about 31% of the patents granted since 2004 are focused on the biomedical area, 29% on food preservation, 5% on veterinary use; whereas 13% and 16% correspond to patents granted on production–purification systems and recombinant proteins or molecular modifications in the producer strains. This review contributes to the analysis of recent LAB bacteriocin applications and their role in safety, quality and improvement of human health.

  17. Cloning, Sequencing, and Expression in Escherichia coli of lcnB, a Third Bacteriocin Determinant from the Lactococcal Bacteriocin Plasmid p9B4-6

    NARCIS (Netherlands)

    Belkum, Marco J. van; Kok, Jan; Venema, Gerhardus

    On the bacteriocin plasmid p9B4-6 of Lactococcus lactis subsp. cremoris 9B4, a third bacteriocin determinant was identified. The genes encoding bacteriocin production and immunity resided on a 1.2-kb CelII-ScaI fragment and were located adjacent to one of two previously identified bacteriocin

  18. Application of Bacteriocins and Protective Cultures in Dairy Food Preservation

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    Célia C. G. Silva

    2018-04-01

    Full Text Available In the last years, consumers are becoming increasingly aware of the human health risk posed by the use of chemical preservatives in foods. In contrast, the increasing demand by the dairy industry to extend shelf-life and prevent spoilage of dairy products has appeal for new preservatives and new methods of conservation. Bacteriocins are antimicrobial peptides, which can be considered as safe since they can be easily degraded by proteolytic enzymes of the mammalian gastrointestinal tract. Also, most bacteriocin producers belong to lactic acid bacteria (LAB, a group that occurs naturally in foods and have a long history of safe use in dairy industry. Since they pose no health risk concerns, bacteriocins, either purified or excreted by bacteriocin producing strains, are a great alternative to the use of chemical preservatives in dairy products. Bacteriocins can be applied to dairy foods on a purified/crude form or as a bacteriocin-producing LAB as a part of fermentation process or as adjuvant culture. A number of applications of bacteriocins and bacteriocin-producing LAB have been reported to successful control pathogens in milk, yogurt, and cheeses. One of the more recent trends consists in the incorporation of bacteriocins, directly as purified or semi-purified form or in incorporation of bacteriocin-producing LAB into bioactive films and coatings, applied directly onto the food surfaces and packaging. This review is focused on recent developments and applications of bacteriocins and bacteriocin-producing LAB for reducing the microbiological spoilage and improve safety of dairy products.

  19. Bacteriocins from lactic acid bacteria as an alternative to antibiotics.

    Science.gov (United States)

    Ołdak, Aleksandra; Zielińska, Dorota

    2017-05-05

    Bacteriocins are ribosomally synthesized, proteinaceous substances that inhibit the growth of closely related species through numerous mechanisms. The classification system used in this review divided bacteriocins into four sub-groups based on their size. Currently, there is extensive research focused on bacteriocins and their usage as a food preservative. The increasing incidence of multidrug resistant bacterial pathogens is one of the most pressing medical problems in recent years. Recently, the potential clinical application of LAB (Lactic Acid Bacteria) bacteriocin has been the subject of investigations by many scientists. Bacteriocins can be considered in a sense as antibiotic, although they differ from conventional antibiotics in numerous aspects. The gene-encoded nature of bacteriocins makes them easily amenable through bioengineering to either increase their activity or specify target microorganism. Owing to this feature of bacteriocins, antibiotic therapy would become less damaging to the natural gut microflora, which is a common drawback of conventional antibiotic use. Bacteriocins from lactic acid bacteria represent one of the most studied microbial defense systems and the idea of subjecting them to bioengineering to either increase antimicrobial activity or further specify their target microorganism is now a rapidly expanding field. This review aimed to present bacteriocins as a possible alternative to conventional antibiotics basic on latest scientific data.

  20. Bacteriocins from lactic acid bacteria as an alternative to antibiotics

    Directory of Open Access Journals (Sweden)

    Aleksandra Ołdak

    2017-05-01

    Full Text Available Bacteriocins are ribosomally synthesized, proteinaceous substances that inhibit the growth of closely related species through numerous mechanisms. The classification system used in this review divided bacteriocins into four sub-groups based on their size. Currently, there is extensive research focused on bacteriocins and their usage as a food preservative.The increasing incidence of multidrug resistant bacterial pathogens is one of the most pressing medical problems in recent years. Recently, the potential clinical application of LAB (Lactic Acid Bacteria bacteriocin has been the subject of investigations by many scientists.Bacteriocins can be considered in a sense as antibiotic, although they differ from conventional antibiotics in numerous aspects. The gene-encoded nature of bacteriocins makes them easily amenable through bioengineering to either increase their activity or specify target microorganism. Owing to this feature of bacteriocins, antibiotic therapy would become less damaging to the natural gut microflora, which is a common drawback of conventional antibiotic use. Bacteriocins from lactic acid bacteria represent one of the most studied microbial defense systems and the idea of subjecting them to bioengineering to either increase antimicrobial activity or further specify their target microorganism is now a rapidly expanding field. This review aimed to present bacteriocins as a possible alternative to conventional antibiotics basic on latest scientific data.

  1. Requirement of autolytic activity for bacteriocin-induced lysis

    NARCIS (Netherlands)

    Martínez-Cuesta, M. Carmen; Kok, Jan; Herranz, Elisabet; Peláez, Carmen; Requena, Teresa; Buist, Girbe

    The bacteriocin produced by Lactococcus lactis IFPL105 is bactericidal against several Lactococcus and Lactobacillus strains. Addition of the bacteriocin to exponential-growth-phase cells resulted in all cases in bacteriolysis. The bacteriolytic response of the strains was not related to differences

  2. Bacteriocins : mechanism of membrane insertion and pore formation

    NARCIS (Netherlands)

    Moll, G.N.; Konings, W.N; Driessen, A.J.M.

    1999-01-01

    Lactic acid bacteria produce several types of pore forming peptides. Class I bacteriocins are lantibiotics that contain (methyl)lanthionine residues that may form intramolecular thioether rings. These peptides generally have a broad spectrum of activity and form unstable pores. Class II bacteriocins

  3. Influence of cultural conditions on the production of bacteriocin by ...

    African Journals Online (AJOL)

    Bacteriocin produced by Lactobacillus brevis OG1 has large spectrum of inhibition against pathogenic, food spoilage microorganisms and various Lactic acid bacteria employed as test strains. The bacteriocin inhibited E coli NCTC 10418 and Enterococcus faecalis, but did not inhibit Candida albicans ATCC 10231 and ...

  4. Bacteriocins: Novel Solutions to Age Old Spore-Related Problems?

    Directory of Open Access Journals (Sweden)

    Kevin eEgan

    2016-04-01

    Full Text Available Bacteriocins are ribosomally synthesized antimicrobial peptides produced by bacteria, which have the ability to kill or inhibit other bacteria. Many bacteriocins are produced by food grade lactic acid bacteria (LAB. Indeed, the prototypic bacteriocin, nisin, is produced by Lactococcus lactis, and is licensed in over 50 countries. With consumers becoming more concerned about the levels of chemical preservatives present in food, bacteriocins offer an alternative, more natural, approach, while ensuring both food safety and product shelf life. Bacteriocins also show additive/synergistic effects when used in combination with other treatments, such as heating, high pressure, organic compounds, and as part of food packaging. These features are particularly attractive from the perspective of controlling sporeforming bacteria. Bacterial spores are common contaminants of food products, and their outgrowth may cause food spoilage or food-borne illness. They are of particular concern to the food industry due to their thermal and chemical resistance in their dormant state. However, when spores germinate they lose the majority of their resistance traits, making them susceptible to a variety of food processing treatments. Bacteriocins represent one potential treatment as they may inhibit spores in the post-germination/outgrowth phase of the spore cycle. Spore eradication and control in food is critical, as they are able to spoil and in certain cases compromise the safety of food by producing dangerous toxins. Thus, understanding the mechanisms by which bacteriocins exert their sporostatic/sporicidal activity against bacterial spores will ultimately facilitate their optimal use in food. This review will focus on the use of bacteriocins alone, or in combination with other innovative processing methods to control spores in food, the current knowledge and gaps therein with regard to bacteriocin-spore interactions and discuss future research approaches to enable

  5. Therapeutic enhancement of newly derived bacteriocins against Giardia lamblia.

    Science.gov (United States)

    Amer, Eglal I; Mossallam, Shereen F; Mahrous, Hoda

    2014-11-01

    Trials for identifying efficient anti-giardial agents are still ongoing. Nowadays, bacteriocins have attracted the attention as potential antimicrobial compounds. For the first time, the current study evaluated the therapeutic efficacy of bacteriocins derived from newly isolated Egyptian strains of probiotics Lactobacilli; L. acidophilus (P106) and L. plantarum (P164) against Giardia lamblia. Bacteriocins' efficacy was evaluated both in vitro; by growth inhibition and adherence assays, and in vivo; through estimation of parasite density, intestinal histopathological examination and ultrastructural analysis of Giardia trophozoites. In vivo bacteriocins' clinical safety was assessed. In vitro results proved that 50 µg of L. acidophilus bacteriocin induced reduction of the mean Giardia lamblia trophozoites by 58.3 ± 4.04%, while at lower concentrations of 10 and 20 µg of both L. acidophilus and L. plantarum, non significant reduction of the mean parasite density was achieved. In vitro trophozoites adherence was susceptible to the tested bacteriocins at all studied concentrations with variable degrees, while the highest adherence reduction was demonstrated using 50 µg of L acidophilus bacteriocin. In vivo, oral inoculation of 50 µg/mouse L. acidophilus bacteriocin for 5 successive days resulted in a noteworthy decline of the intestinal parasite density, along with amelioration of intestinal pathology of infected mice. Ultrastructural examination proved thatfive doses of L. acidophilus bacteriocin showed marked changes in cellular architecture of the trophozoites with evident disorganization of the cell membrane, adhesive disc and cytoplasmic components. This is the first reported study of the safe anti-giardial efficacy of L. acidophilus (P106) derived bacteriocin, hence highlighting its great promise as a potential therapeutic safe alternative to existing commercial drugs. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Bacteriocins: Novel Solutions to Age Old Spore-Related Problems?

    Science.gov (United States)

    Egan, Kevin; Field, Des; Rea, Mary C; Ross, R Paul; Hill, Colin; Cotter, Paul D

    2016-01-01

    Bacteriocins are ribosomally synthesized antimicrobial peptides produced by bacteria, which have the ability to kill or inhibit other bacteria. Many bacteriocins are produced by food grade lactic acid bacteria (LAB). Indeed, the prototypic bacteriocin, nisin, is produced by Lactococcus lactis, and is licensed in over 50 countries. With consumers becoming more concerned about the levels of chemical preservatives present in food, bacteriocins offer an alternative, more natural approach, while ensuring both food safety and product shelf life. Bacteriocins also show additive/synergistic effects when used in combination with other treatments, such as heating, high pressure, organic compounds, and as part of food packaging. These features are particularly attractive from the perspective of controlling sporeforming bacteria. Bacterial spores are common contaminants of food products, and their outgrowth may cause food spoilage or food-borne illness. They are of particular concern to the food industry due to their thermal and chemical resistance in their dormant state. However, when spores germinate they lose the majority of their resistance traits, making them susceptible to a variety of food processing treatments. Bacteriocins represent one potential treatment as they may inhibit spores in the post-germination/outgrowth phase of the spore cycle. Spore eradication and control in food is critical, as they are able to spoil and in certain cases compromise the safety of food by producing dangerous toxins. Thus, understanding the mechanisms by which bacteriocins exert their sporostatic/sporicidal activity against bacterial spores will ultimately facilitate their optimal use in food. This review will focus on the use of bacteriocins alone, or in combination with other innovative processing methods to control spores in food, the current knowledge and gaps therein with regard to bacteriocin-spore interactions and discuss future research approaches to enable spores to be more

  7. Bacteriocins: Novel Solutions to Age Old Spore-Related Problems?

    Science.gov (United States)

    Egan, Kevin; Field, Des; Rea, Mary C.; Ross, R. Paul; Hill, Colin; Cotter, Paul D.

    2016-01-01

    Bacteriocins are ribosomally synthesized antimicrobial peptides produced by bacteria, which have the ability to kill or inhibit other bacteria. Many bacteriocins are produced by food grade lactic acid bacteria (LAB). Indeed, the prototypic bacteriocin, nisin, is produced by Lactococcus lactis, and is licensed in over 50 countries. With consumers becoming more concerned about the levels of chemical preservatives present in food, bacteriocins offer an alternative, more natural approach, while ensuring both food safety and product shelf life. Bacteriocins also show additive/synergistic effects when used in combination with other treatments, such as heating, high pressure, organic compounds, and as part of food packaging. These features are particularly attractive from the perspective of controlling sporeforming bacteria. Bacterial spores are common contaminants of food products, and their outgrowth may cause food spoilage or food-borne illness. They are of particular concern to the food industry due to their thermal and chemical resistance in their dormant state. However, when spores germinate they lose the majority of their resistance traits, making them susceptible to a variety of food processing treatments. Bacteriocins represent one potential treatment as they may inhibit spores in the post-germination/outgrowth phase of the spore cycle. Spore eradication and control in food is critical, as they are able to spoil and in certain cases compromise the safety of food by producing dangerous toxins. Thus, understanding the mechanisms by which bacteriocins exert their sporostatic/sporicidal activity against bacterial spores will ultimately facilitate their optimal use in food. This review will focus on the use of bacteriocins alone, or in combination with other innovative processing methods to control spores in food, the current knowledge and gaps therein with regard to bacteriocin-spore interactions and discuss future research approaches to enable spores to be more

  8. Potency Of Bacteriocin For Animal Health And Food Safety

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    Siti Chotiah

    2013-06-01

    Full Text Available The emergence of antibiotic resistance in many bacteria related to animal and public health stresses the importance of decreasing the use of antibiotics in animal production. The reduction of antibiotic application in livestock can only be achieved if alternative antimicrobial strategies are available. A number of strategies have been explored to control microbial pathogens and to improve growth and feed efficiency in livestock without the use of antibiotics. Bacteriocins have been more extensively studied and proposed as potential alternatives to conventional antibiotics in animal husbandry. Bacteriocins are antimicrobial peptides ribosomally synthesized by many species of Bacteria and some strains of Archaea. In general, bacteriocins just exhibited bactericidal or bacteriostatic activity against other bacteria that are closely related to the producing strain. The main mechanisms of bacteriocin activity vary from pore formation in cytoplasmic membranes to the inhibition of cell wall biosynthesis and enzyme activities (RNAse or DNAse in target cells. The use of bacteriocins in probiotic applications, as preservatives, and most excitingly as alternatives to conventional antibiotics is being broadly explored and studied. This review will describe the bacteriocins potency for animal health and food safety, as well as the results of bacteriocin study that had been conducted in Indonesia.

  9. Bacteriocins as food preservatives: Challenges and emerging horizons.

    Science.gov (United States)

    Johnson, Eldin Maliyakkal; Jung, Dr Yong-Gyun; Jin, Dr Ying-Yu; Jayabalan, Dr Rasu; Yang, Dr Seung Hwan; Suh, Joo Won

    2017-09-07

    The increasing demand for fresh-like food products and the potential health hazards of chemically preserved and processed food products have led to the advent of alternative technologies for the preservation and maintenance of the freshness of the food products. One such preservation strategy is the usage of bacteriocins or bacteriocins producing starter cultures for the preservation of the intended food matrixes. Bacteriocins are ribosomally synthesized smaller polypeptide molecules that exert antagonistic activity against closely related and unrelated group of bacteria. This review is aimed at bringing to lime light the various class of bacteriocins mainly from gram positive bacteria. The desirable characteristics of the bacteriocins which earn them a place in food preservation technology, the success story of the same in various food systems, the various challenges and the strategies employed to put them to work efficiently in various food systems has been discussed in this review. From the industrial point of view various aspects like the improvement of the producer strains, downstream processing and purification of the bacteriocins and recent trends in engineered bacteriocins has also been briefly discussed in this review.

  10. Antimicrobial potential of bacteriocins: in therapy, agriculture and food preservation.

    Science.gov (United States)

    Ahmad, Varish; Khan, Mohd Sajid; Jamal, Qazi Mohammad Sajid; Alzohairy, Mohammad A; Al Karaawi, Mohammad A; Siddiqui, Mughees Uddin

    2017-01-01

    Due to the appearance of antibiotic resistance and the toxicity associated with currently used antibiotics, peptide antibiotics are the need of the hour. Thus, demand for new antimicrobial agents has brought great interest in new technologies to enhance safety. One such antimicrobial molecule is bacteriocin, synthesised by various micro-organisms. Bacteriocins are widely used in agriculture, veterinary medicine as a therapeutic, and as a food preservative agent to control various infectious and food-borne pathogens. In this review, we highlight the potential therapeutic and food preservative applications of bacteriocin. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  11. Bacteriocins of lactic acid bacteria: extending the family.

    Science.gov (United States)

    Alvarez-Sieiro, Patricia; Montalbán-López, Manuel; Mu, Dongdong; Kuipers, Oscar P

    2016-04-01

    Lactic acid bacteria (LAB) constitute a heterogeneous group of microorganisms that produce lactic acid as the major product during the fermentation process. LAB are Gram-positive bacteria with great biotechnological potential in the food industry. They can produce bacteriocins, which are proteinaceous antimicrobial molecules with a diverse genetic origin, posttranslationally modified or not, that can help the producer organism to outcompete other bacterial species. In this review, we focus on the various types of bacteriocins that can be found in LAB and the organization and regulation of the gene clusters responsible for their production and biosynthesis, and consider the food applications of the prototype bacteriocins from LAB. Furthermore, we propose a revised classification of bacteriocins that can accommodate the increasing number of classes reported over the last years.

  12. Partial characterization of bacteriocins produced by Lactobacillus acidophilus and Pediococcus acidilactici

    Directory of Open Access Journals (Sweden)

    Nallusamy Sivakumar

    2010-10-01

    Full Text Available Bacteriocin producing Lactobacillus acidophilus and Pediococcus acidilactici were isolated from milk and meat samples, respectively. An attempt was made to produce bacteriocin in a Dairy Based (DB medium using these organisms. Higher bacteriocin activity was shown by L. acidophilus in the DB medium. Bacteriocins of both the organisms were effective against food pathogens. The bacteriocins were stable at pH 3 - 9 up to 24 h and active at 100ºC. The bacteriocins could be stored at -20ºC for at least 45 days, at 4ºC for 20 days and at 37ºC for 5 days.

  13. Utilization of bacteriocin-producing bacteria in dairy products

    Directory of Open Access Journals (Sweden)

    Matěj Patrovský

    2016-07-01

    Full Text Available Lactic acid bacteria have been used since ancient times for food preparation and for bio-conservation by fermentation. Selected strains are capable of producing antimicrobial peptides - bacteriocins, which can be natural preservatives, especially in products with short shelf lives. The present study is focused on inhibitory effects of the bacteriocin-producing bacteria strains Enterococcus faecium, Pediococccus acidilactici and Lactobacillus plantarum against Listeria innocua as an indicator microorganism. Freeze-dried preparations of bacterial strains producing particular bacteriocins were tested by agar well-diffusion assay and by the traditional spread plate method. Plantaricin exhibited the highest anti-listerial effect among the tested bacteriocins. Pediocin also demonstrated a distinct inhibitory effect, but enterocin appeared to be heat labile and its efficiency was also suppressed under cold storage conditions. Plantaricin reduced Listeria innocua counts by 1 log in dairy spread made from cheese and quark. The formation of bacteriocins by various Lactobacillus plantarum strains were substantially influenced by the cultivation conditions of the mother culture and by the microbial preparation process before freeze-drying. Bacteriocins introduced into foodstuffs via protective cultures in situ offer new perspectives on enhancing food quality and safety.

  14. BACTERIOCINS AND BACTERIOPHAGE LYTIC PROTEINS AS ALTERNATIVES TO ANTIBIOTICS FROM RUSSIAN FEDERATION AND USA COLLABORATIONS

    Science.gov (United States)

    Novel anti-microbial peptides (bacteriocins) were isolated and characterized in collaborative research between PMSRU, ARS-USDA scientists and representatives of the State Research Center for Applied Microbiology and Biotechnology (SRCAMB) in Obolensk, Russian Federation. The bacteriocins are effect...

  15. Bacteriocins of Non-aureus Staphylococci Isolated from Bovine Milk.

    Science.gov (United States)

    Carson, Domonique A; Barkema, Herman W; Naushad, Sohail; De Buck, Jeroen

    2017-09-01

    Non- aureus staphylococci (NAS), the bacteria most commonly isolated from the bovine udder, potentially protect the udder against infection by major mastitis pathogens due to bacteriocin production. In this study, we determined the inhibitory capability of 441 bovine NAS isolates (comprising 26 species) against bovine Staphylococcus aureus Furthermore, inhibiting isolates were tested against a human methicillin-resistant S. aureus (MRSA) isolate using a cross-streaking method. We determined the presence of bacteriocin clusters in NAS whole genomes using genome mining tools, BLAST, and comparison of genomes of closely related inhibiting and noninhibiting isolates and determined the genetic organization of any identified bacteriocin biosynthetic gene clusters. Forty isolates from 9 species ( S. capitis , S. chromogenes , S. epidermidis , S. pasteuri , S. saprophyticus , S. sciuri , S. simulans , S. warneri , and S. xylosus ) inhibited growth of S. aureus in vitro , 23 isolates of which, from S. capitis , S. chromogenes , S. epidermidis , S. pasteuri , S. simulans , and S. xylosus , also inhibited MRSA. One hundred five putative bacteriocin gene clusters encompassing 6 different classes (lanthipeptides, sactipeptides, lasso peptides, class IIa, class IIc, and class IId) in 95 whole genomes from 16 species were identified. A total of 25 novel bacteriocin precursors were described. In conclusion, NAS from bovine mammary glands are a source of potential bacteriocins, with >21% being possible producers, representing potential for future characterization and prospective clinical applications. IMPORTANCE Mastitis (particularly infections caused by Staphylococcus aureus ) costs Canadian dairy producers $400 million/year and is the leading cause of antibiotic use on dairy farms. With increasing antibiotic resistance and regulations regarding use, there is impetus to explore bacteriocins (bacterially produced antimicrobial peptides) for treatment and prevention of bacterial

  16. Bacteriocins of Non-aureus Staphylococci Isolated from Bovine Milk

    Science.gov (United States)

    Carson, Domonique A.; Barkema, Herman W.; Naushad, Sohail

    2017-01-01

    ABSTRACT Non-aureus staphylococci (NAS), the bacteria most commonly isolated from the bovine udder, potentially protect the udder against infection by major mastitis pathogens due to bacteriocin production. In this study, we determined the inhibitory capability of 441 bovine NAS isolates (comprising 26 species) against bovine Staphylococcus aureus. Furthermore, inhibiting isolates were tested against a human methicillin-resistant S. aureus (MRSA) isolate using a cross-streaking method. We determined the presence of bacteriocin clusters in NAS whole genomes using genome mining tools, BLAST, and comparison of genomes of closely related inhibiting and noninhibiting isolates and determined the genetic organization of any identified bacteriocin biosynthetic gene clusters. Forty isolates from 9 species (S. capitis, S. chromogenes, S. epidermidis, S. pasteuri, S. saprophyticus, S. sciuri, S. simulans, S. warneri, and S. xylosus) inhibited growth of S. aureus in vitro, 23 isolates of which, from S. capitis, S. chromogenes, S. epidermidis, S. pasteuri, S. simulans, and S. xylosus, also inhibited MRSA. One hundred five putative bacteriocin gene clusters encompassing 6 different classes (lanthipeptides, sactipeptides, lasso peptides, class IIa, class IIc, and class IId) in 95 whole genomes from 16 species were identified. A total of 25 novel bacteriocin precursors were described. In conclusion, NAS from bovine mammary glands are a source of potential bacteriocins, with >21% being possible producers, representing potential for future characterization and prospective clinical applications. IMPORTANCE Mastitis (particularly infections caused by Staphylococcus aureus) costs Canadian dairy producers $400 million/year and is the leading cause of antibiotic use on dairy farms. With increasing antibiotic resistance and regulations regarding use, there is impetus to explore bacteriocins (bacterially produced antimicrobial peptides) for treatment and prevention of bacterial infections

  17. Pseudomonas putida Strain FStm2 Isolated from Shark Skin: A Potential Source of Bacteriocin.

    Science.gov (United States)

    Ahmad, Asmat; Hamid, Rahimi; Dada, Ayokunle Christopher; Usup, Gires

    2013-09-01

    Bacteriocin-producing Pseudomonas putida strain FStm2 isolated from shark showed broad range of antibacterial activity against all pathogens tested except Bacillus subtilis ATCC11774, MRSA N32064, Proteus mirabilis ATCC12453, Enterococcus faecalis ATCC14506, Salmonella typhimurium ATCC51312, Salmonella mutan ATCC25175, and Aeromonas hydrophila Wbf314. Of the three growth media tested in this study, TSB was observed to support the bacteriocin activity the most. While the highest bacteriocin activity was observed for media supplemented with 1 % NaCl, there was an observed reduction in bacteriocin activity with increasing salt concentration. Although the least bacteriocin activity was observed for marine broth, addition of increasing amounts of tryptone, glucose, or yeast extract increased bacteriocin activity. This was, however, contrary to the effect observed when MgSO4 and MnSO4 were added as supplements. In the presence of α-amylase, lipase, DNase, and RNase, a positive effect on bacteriocin production was observed. Proteinase K strongly inhibited bacteriocin production. Furthermore, the bacteriocins produced were heat stable within the temperature range of 30-70 °C. Bacteriocin activity also was not affected within a wide pH range of 3-9. Exposure to detergents did not inhibit the activity of the bacteriocin at the concentrations tested. Instead, a positive effect on the relative activity of produced bacteriocin was observed as sodium dodecyl sulfate (SDS), EDTA, and Tween 20 at 1 % concentration all improved bacteriocin activity when the cell-free supernatant was tested against Serratia marcescens ATCC 13880. The bacteriocin was purified by ammonium sulfate precipitation and gel filtration on a Superdex-200 column. SDS-PAGE analysis of the partially purified bacteriocin revealed an apparent molecular weight of ~32 kDa.

  18. Bacteriocins produced by lactic acid bacteria: A review

    Directory of Open Access Journals (Sweden)

    Vesković-Moračanin Slavica M.

    2014-01-01

    Full Text Available Lactic acid bacteria (LAB have an essential role in the production of fermented products. With their metabolic activity, they influence the ripening processes - leading to desired sensory qualities while at the same time inhibiting the growth of undesired microorganisms. Because of their dominant role during fermentation and because of a long tradition of utilization, Lhave been designated as “safe microbiota”. Biological protection of LAB, as a naturally present and/or selected and intentionally added microflora, is realized through the production of non-specific (lactic acid, acetic acid and other volatile organic acids, hydrogen peroxide, diacetyl, etc and specific metabolites, bacteriocins. Bacteriocins are extracellularly released proteins or peptides which possess certain antibacterial activity towards certain types of microorganisms, usually related to the producing bacteria. Today, bacteriocins represent a very interesting potential for their application in the food industry. Their application can reduce the use of synthetic preservatives and/or the intensity of thermal treatment during food production consumer’s need for safe, fresh and minimally-processed food. With the intention of realizing this potential to the fullest, it is necessary to understand the nature of bacteriocins, their production mechanisms, regulations and actions, as well as the influence of external factors on the their antimicrobial activity. The composition of food, i.e. its characteristics (pH, temperature, ingredients and additives, types and quantities of epiphytic microbiota and the actual technological process used in production, can all influence the stability and activity of the added bacteriocins. The future research in this field should also aim to clarify this unknown aspect of the application of bacteriocins, to provide the necessary knowledge about the optimization of the external conditions and open up the possibility of discovering their new

  19. Bacteriocins from the rhizosphere microbiome – from an agriculture perspective

    Directory of Open Access Journals (Sweden)

    Sowmyalakshmi eSubramanian

    2015-10-01

    Full Text Available Bacteria produce and excrete a versatile and dynamic suit of compounds to defend against microbial competitors and mediate local population dynamics. These include a wide range of broad-spectrum non-ribosomally synthesized antibiotics, lytic enzymes, metabolic by-products, proteinaceous exotoxins and ribosomally produced antimicrobial peptides (bacteriocins. Most bacteria produce at least one bacteriocin. Bacteriocins are of interest in the food industry as natural preservatives and in the probiotics industry, leading to extensive studies on lactic acid bacteria (colicin produced by Escherichia coli is a model bacteriocin. Recent studies have projected use of bacteriocins in veterinary medicine and in agriculture, as a biostimulants of plant growth and development and as biocontrol agents. For example, bacteriocins such as Cerein 8A, Bac-GM17, putidacin, Bac 14B, amylocyclicin have been studied for their mechanisms of anti-microbial activity. Bac IH7 promotes tomato and musk melon plant growth. Thuricin 17 (Th17 is the only bacteriocin studied extensively for plant growth promotion and at the molecular level. Th17 functions as a bacterial signal compound, promoting plant growth in legumes and non-legumes. In Arabidopsis thaliana and Glycine max Th17 increased phytohormones IAA and SA at 24 h post treatment. At the proteome level Th17 treatment of 3-week-old A. thaliana rosettes led to > 2-fold changes in activation of the carbon and energy metabolism pathway proteins, 24 h post treatment. At 250 mM NaCl stress, the control plants under osmotic-shock shut down most of carbon-metabolism and activated energy-metabolism and antioxidant pathways. Th17 treated plants, at 250 mM NaCl, retained meaningful levels of the light harvesting complex, photosystem I and II proteins and energy and antioxidant pathways were activated, so that rosettes could better withstand the salt stress. In Glycine max, Th17 helped seeds germinate in the presence of Na

  20. Current state of purification, isolation and analysis of bacteriocins produced by lactic acid bacteria.

    Science.gov (United States)

    Kaškonienė, Vilma; Stankevičius, Mantas; Bimbiraitė-Survilienė, Kristina; Naujokaitytė, Gintarė; Šernienė, Loreta; Mulkytė, Kristina; Malakauskas, Mindaugas; Maruška, Audrius

    2017-02-01

    The scientific interest for the search of natural means of microbial inhibitors has not faded for several years. A search of natural antibiotics, so-called bacteriocins which are produced by lactic acid bacteria (LAB), gains a huge attention of the scientists in the last century, in order to reduce the usage of synthetic food additives. Pure bacteriocins with wide spectra of antibacterial activity are promising among the natural biopreservatives. The usage of bacteriocin(s) producing LAB as starter culture for the fermentation of some food products, in order to increase their shelf-life, when synthetic preservatives are not allowable, is also possible. There are a lot of studies focusing on the isolation of new bacteriocins from traditional fermented food, dairy products and other foods or sometimes even from unusual non-food matrices. Bacteriocins producing bacteria have been isolated from different sources with the different antibacterial activity against food-borne microorganisms. This review covers the classification of bacteriocins, diversity of sources of bacteriocin(s) producing LAB, antibacterial spectra of isolated bacteriocins and analytical methods for the bacteriocin purification and analysis within the last 15 years.

  1. The weak shall inherit: bacteriocin-mediated interactions in bacterial populations.

    Directory of Open Access Journals (Sweden)

    Hadeel Majeed

    Full Text Available Evolutionary arms race plays a major role in shaping biological diversity. In microbial systems, competition often involves chemical warfare and the production of bacteriocins, narrow-spectrum toxins aimed at killing closely related strains by forming pores in their target's membrane or by degrading the target's RNA or DNA. Although many empirical and theoretical studies describe competitive exclusion of bacteriocin-sensitive strains by producers of bacteriocins, the dynamics among producers are largely unknown.We used a reporter-gene assay to show that the bacterial response to bacteriocins' treatment mirrors the inflicted damage Potent bacteriocins are lethal to competing strains, but at sublethal doses can serve as strong inducing agents, enhancing their antagonists' bacteriocin production. In contrast, weaker bacteriocins are less toxic to their competitors and trigger mild bacteriocin expression. We used empirical and numerical models to explore the role of cross-induction in the arms race between bacteriocin-producing strains. We found that in well-mixed, unstructured environments where interactions are global, producers of weak bacteriocins are selectively advantageous and outcompete producers of potent bacteriocins. However, in spatially structured environments, where interactions are local, each producer occupies its own territory, and competition takes place only in "no man's lands" between territories, resulting in much slower dynamics.The models we present imply that producers of potent bacteriocins that trigger a strong response in neighboring bacteriocinogenic strains are doomed, while producers of weak bacteriocins that trigger a mild response in bacteriocinogenic strains flourish. This counter-intuitive outcome might explain the preponderance of weak bacteriocin producers in nature. However, the described scenario is prolonged in spatially structured environments thus promoting coexistence, allowing migration and evolution, and

  2. Using the overlay assay to qualitatively measure bacterial production of and sensitivity to pneumococcal bacteriocins.

    Science.gov (United States)

    Maricic, Natalie; Dawid, Suzanne

    2014-09-30

    Streptococcus pneumoniae colonizes the highly diverse polymicrobial community of the nasopharynx where it must compete with resident organisms. We have shown that bacterially produced antimicrobial peptides (bacteriocins) dictate the outcome of these competitive interactions. All fully-sequenced pneumococcal strains harbor a bacteriocin-like peptide (blp) locus. The blp locus encodes for a range of diverse bacteriocins and all of the highly conserved components needed for their regulation, processing, and secretion. The diversity of the bacteriocins found in the bacteriocin immunity region (BIR) of the locus is a major contributor of pneumococcal competition. Along with the bacteriocins, immunity genes are found in the BIR and are needed to protect the producer cell from the effects of its own bacteriocin. The overlay assay is a quick method for examining a large number of strains for competitive interactions mediated by bacteriocins. The overlay assay also allows for the characterization of bacteriocin-specific immunity, and detection of secreted quorum sensing peptides. The assay is performed by pre-inoculating an agar plate with a strain to be tested for bacteriocin production followed by application of a soft agar overlay containing a strain to be tested for bacteriocin sensitivity. A zone of clearance surrounding the stab indicates that the overlay strain is sensitive to the bacteriocins produced by the pre-inoculated strain. If no zone of clearance is observed, either the overlay strain is immune to the bacteriocins being produced or the pre-inoculated strain does not produce bacteriocins. To determine if the blp locus is functional in a given strain, the overlay assay can be adapted to evaluate for peptide pheromone secretion by the pre-inoculated strain. In this case, a series of four lacZ-reporter strains with different pheromone specificity are used in the overlay.

  3. Growth of Enterococcus durans E204 producing bacteriocin-like ...

    African Journals Online (AJOL)

    Bacteriocin-like substance E204 is an antimicrobial compound produced by Enterococcus durans E204 isolated from camel milk of Morocco that shows a broad spectrum of inhibitory activity against taxonomically related microorganisms. It is sensitive to digestive proteases. In the first study, de Man, Regosa and Sharpe ...

  4. Bacteriocin and cellulose production by lactic acid bacteria isolated ...

    African Journals Online (AJOL)

    Sixteen colonies of lactic acid bacteria (LAB) were selected and screened for their ability to produce bacteriocin by agar well diffusion method using the supernatant of centrifuged test cultures. Four isolates inhibited the growth of Listeria monocytogenes and Escherichia coli. Lactobacillus plantarum (6) and Lactobacillus ...

  5. Bacteriocin-mediated competition in cystic fibrosis lung infections

    DEFF Research Database (Denmark)

    Ghoul, Melanie; West, Stuart A.; Johansen, Helle Krogh

    2015-01-01

    , especially human pathogens, remains to be tested. We examined the role of bacteriocins in competition using Pseudomonas aeruginosa strains infecting lungs of humans with cystic fibrosis (CF). We assessed the ability of different strains to kill each other using phenotypic assays, and sequenced their genomes...

  6. Bacteriocin and cellulose production by lactic acid bacteria isolated ...

    African Journals Online (AJOL)

    SERVER

    2007-11-19

    after 20 and 25 min) and E. coli 0157:H7 (after 15, 20 and 25 ... in a coculture with various Lactobacillus mali strains showed that cell-cell .... were found to be capable of producing viable bacteriocin can be purified and charac-.

  7. Thermophilin 110: a bacteriocin of Streptococcus thermophilus ST110.

    Science.gov (United States)

    Gilbreth, Stefanie E; Somkuti, George A

    2005-09-01

    A screen of thermophilic lactic acid bacteria identified Streptococcus thermophilus strain ST110 as the putative producer of a bacteriocin with high level of activity against pediococci. Thermophilin 110 was isolated from culture supernatant after 16 h of growth and partially purified by a chloroform extraction procedure. The bacteriocin inhibited the growth of several lactic acid bacteria and in the case of Pediococcus acidilactici, it induced cell lysis with the concomitant release of OD260-absorbing material and intracellular enzymes. SDS-PAGE analysis revealed two components with estimated sizes between 4.0 kDa and 4.5 kDa, respectively, with possible involvement in bacteriocin activity as indicated by agar overlay assays with P. acidilactici as the target organism. Thermophilin 110 was inactivated by several proteolytic enzymes and also by alpha-amylase, which indicated the putative requirement of a glycosidic component for activity. The bacteriocin produced by S. thermophilus may be especially useful in the food processing industries to control spoilage caused by pediococci.

  8. Bacteriocins of lactic acid bacteria : extending the family

    NARCIS (Netherlands)

    Alvarez-Sieiro, Patricia; Montalbán-López, Manuel; Mu, Dongdong; Kuipers, Oscar P

    2016-01-01

    Lactic acid bacteria (LAB) constitute a heterogeneous group of microorganisms that produce lactic acid as the major product during the fermentation process. LAB are Gram-positive bacteria with great biotechnological potential in the food industry. They can produce bacteriocins, which are

  9. Fungicidal effect of bacteriocins harvested from Bacillus spp.

    Directory of Open Access Journals (Sweden)

    Adetunji, V. O.

    2013-01-01

    Full Text Available Aims: This study investigated the ability of bacteriocins isolated from Bacillus spp. (Bacillus species to inhibit fourdifferent yeast isolates obtained from common food products (nono, yoghurt, ogi and cheese commonly consumed byNigerians with minimal heat treatment.Methodology and results: Forty-five Bacillus spp. was isolated and identified from common food products usingcultural, morphological, physiological and biochemical characteristics. These isolates were tested for antimicrobialactivity against Salmonella enteritidis (3, Micrococcus luteus (1 and Staphylococcus aureus (2. Eight bacteriocinproducing strains were identified from an over- night broth culture centrifugated at 3500 revolutions for five minutes.Fungicidal effects of these bacteriocins were tested against four yeast strains using the Agar Well Diffusion method. Thebacteriocins produced wide zones of inhibition ranging from 5.9±0.000 to 24.00±0.000 mm against the 4 yeast strainstested. There was a significant difference (at p<0.05 between the yeast organisms and the bacteriocins from theBacillus spp.Conclusion, significance and impact of study: The study reveals the antifungal property of bacteriocins from Bacillusspp. and serves therefore as a base for further studies in its use in the control of diseases and extension of shelf-life ofproducts prone to fungi contamination.

  10. Cultivation, isolation and characterization of bacteriocin from fresh ...

    African Journals Online (AJOL)

    This study focus on cultivation, isolation and characterization of Bacteriocin from fresh cow milk (FCM) and fresh cow meat (FMS) samples obtained from Lapai Market in Niger State, Nigeria. Potential bacteriocinogenic bacteria were screened with agar diffusion method on culture plates seeded with Staphylococcus and ...

  11. The Circular Bacteriocins Gassericin A and Circularin A

    NARCIS (Netherlands)

    Kawai, Yasushi; Kemperman, Rober; Kok, Jan; Saito, Tadao

    2004-01-01

    Gassericin A, a bacteriocin produced by Lactobacillus gasseri LA39, shows antibacterial activity against a number of Gram-positive food-borne pathogenic bacteria. Circularin A produced by Clostridium beijerinckii ATCC25752 is active against C. tyrobutyricum, a known cheese-spoilage bacterium. Both

  12. Organization and Nucleotide Sequences of Two Lactococcal Bacteriocin Operons

    NARCIS (Netherlands)

    Belkum, Marco J. van; Hayema, Bert Jan; Jeeninga, Rienk E.; Kok, Jan; Venema, Gerard

    Two distinct regions of the Lactococcus lactis subsp. cremoris 9B4 plasmid p9B4-6, each of which specified bacteriocin production as well as immunity, have been sequenced and analyzed by deletion and frameshift mutation analyses. On a 1.8-kb ScaI-ClaI fragment specifying low antagonistic activity,

  13. Purification of bacteriocins using size-exclusion chromatography

    Directory of Open Access Journals (Sweden)

    Vivek K. Bajpai

    2016-06-01

    Full Text Available The bacteriocin purification involves following main steps. a. Extraction of cell-free-supernatant of bacteria. b. Ammonium sulfate precipitation. c. Dialysis. d. Diafiltration using PVP and e. Size-exclusion chromatography. However, depending on the nature of work, the compound could be further analyzed by reverse-phase HPLC, NMR, mass spectrometry and sequencing.

  14. Cultivation, Isolation and Characterization of Bacteriocin from Fresh ...

    African Journals Online (AJOL)

    ADOWIE PERE

    sensitive, as only one among three species of. Lactobacillus plot was correlatively strong. Delgado et al. (2005) also demonstrated that quotients of linear parallel models of zone of inhibition and indicator organisms' sensitivity are capable of quantifying bacteriocin activity. Both references above utilized relativity principles ...

  15. Different bacteriocin activities of Streptococcus mutans reflect distinct phylogenetic lineages

    DEFF Research Database (Denmark)

    Balakrishnan, M; Simmonds, RS; Kilian, Mogens

    2002-01-01

    Bacteriocins produced by mutans streptococci are known as mutacins. In this study 16 broadly active mutacin-producing Streptococcus mutans strains from New Zealand, North America and Europe were classified into four groups (A-D) on the basis of differences in their activity in deferred antagonism...

  16. Effect of Bacteriocin-like Inhibitory Substances Produced by Vaginal ...

    African Journals Online (AJOL)

    Reduction of vaginal Lactobacillus population leads to overgrowth of opportunistic organisms such as Streptococcus agalactiae (Group B Streptococcus, GBS), which causes life threatening neonatal infections. The activities of bacteriocin-like inhibitory substances (BLIS) produced by Lactobacillus species isolated from the ...

  17. Characterization of Class IIa Bacteriocin Resistance in Enterococcus faecium.

    Science.gov (United States)

    Geldart, Kathryn; Kaznessis, Yiannis N

    2017-04-01

    Vancomycin-resistant enterococci, particularly resistant Enterococcus faecium , pose an escalating threat in nosocomial environments because of their innate resistance to many antibiotics, including vancomycin, a treatment of last resort. Many class IIa bacteriocins strongly target these enterococci and may offer a potential alternative for the management of this pathogen. However, E. faecium 's resistance to these peptides remains relatively uncharacterized. Here, we explored the development of resistance of E. faecium to a cocktail of three class IIa bacteriocins: enterocin A, enterocin P, and hiracin JM79. We started by quantifying the frequency of resistance to these peptides in four clinical isolates of E. faecium We then investigated the levels of resistance of E. faecium 6E6 mutants as well as their fitness in different carbon sources. In order to elucidate the mechanism of resistance of E. faecium to class IIa bacteriocins, we completed whole-genome sequencing of resistant mutants and performed reverse transcription-quantitative PCR (qRT-PCR) of a suspected target mannose phosphotransferase (ManPTS). We then verified this ManPTS's role in bacteriocin susceptibility by showing that expression of the ManPTS in Lactococcus lactis results in susceptibility to the peptide cocktail. Based on the evidence found from these studies, we conclude that, in accord with other studies in E. faecalis and Listeria monocytogenes , resistance to class IIa bacteriocins in E. faecium 6E6 is likely caused by the disruption of a particular ManPTS, which we believe we have identified. Copyright © 2017 American Society for Microbiology.

  18. POTENTIAL IN VITRO ANTI-HELICOBACTER ACTIVITY OF BACTERIOCIN AND BACTERIOCIN-LIKE COMPOUNDS PRODUCED BY LACTOBACILLI

    Directory of Open Access Journals (Sweden)

    Mohammed A. Ramadan

    2014-10-01

    Full Text Available The study was designed for screening of the potential activity of lactic acid bacteria against Helicobacter pylori and other enteropathogenic organisms. A total of 40 samples including natural cow milk and fresh infant stools were tested for the presence of lactic acid bacteria. Of these samples, 73 lactic acid bacterial isolates were recovered on MRS agar medium using the streak-plate method. Isolates inducing probiotic effect were tested under microaerophilic conditions against standard cultures of H. pylori, Esherichia coli and Salmonella enteritidis. The data obtained showed that five isolates of lactic acid bacteria were able to produce bacteriocin or bacteriocin-like compounds. Sequencing of 16S rRNA gene revealed that five isolates belonged to Lactobacillus rhamnosus and Lactobacillus plantarum in addition to other lactic acid bacteria. The most effective isolate (LAB1 showed a marked large inhibition zone against H. pylori. The bacteriocin or bacteriocin like compound(s produced by lactobacilli were further analyzed and characterized. We can conclude that probiotics might be useful in the prophylaxis or as co-therapy for treatment of H. pylori infections.

  19. Demonstration of bacteriocin activity in bovine and bison strains of Pasteurella multocida. [UV radiation

    Energy Technology Data Exchange (ETDEWEB)

    Chengappa, M.M.; Carter, G.R.

    1977-08-01

    Of 33 strains of Pasteurella multocida examined, 14 showed bacteriocin activity and 17 were susceptible to bacteriocin. The activity was increased by about twofold if the cultures were induced with ultraviolet radiation; however, no increase in bacteriocin activity was observed if the potential producer strains were induced with mitomycin C. The bacteriocin activity of potential producer strains was increased if CaCl/sub 2/ was incorporated in the medium. The patterns of bacteriocin susceptibility indicate that these substances may ultimately contribute to a typing scheme for the species. An extra-chromosomal genetic element was not detected when a potential producer strain was not detected when a potential producer strain was tested by the dye-buoyant density gradient method. This fact suggests that the genetic material responsible for bacteriocin activity in P multocida is located on the host chromosome proper.

  20. Lack of Heterogeneity in Bacteriocin Production Across a Selection of Commercial Probiotic Products.

    Science.gov (United States)

    Hegarty, J W; Guinane, C M; Ross, R P; Hill, C; Cotter, P D

    2017-12-01

    Probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit to the host. Bacteriocin production has often been mooted as a desirable probiotic trait and, in specific cases, has been shown to promote probiotic survival within the gastrointestinal tract, contribute to the control of pathogens and even influence host gene expression in the gut. However, it is not clear what proportion of probiotic strains routinely found in commercial products produces bacteriocins, and additionally, it is not known which bacteriocins are produced most frequently. To address this, we conducted a culture-based assessment of the bacteriocinogenic ability of bacterial strains found in a variety of commercially available probiotic products. We detected eight bacteriocin-producing isolates from 16 tested products. Interestingly, in all cases, the isolates were Lactobacillus acidophilus, and the bacteriocin produced was identified as the narrow spectrum class II bacteriocin, lactacin B. The apparent absence of other bacteriocin-producing strains from across these products suggests a lack of heterogeneity in bacteriocin production within probiotic products and suggests that bacteriocin production is not being optimally harnessed as a probiotic trait.

  1. History, Current Knowledge, and Future Directions on Bacteriocin Research in Lactic Acid Bacteria

    Science.gov (United States)

    Nes, Ingolf F.

    All organisms, both eukaryotic organisms and bacteria, are able to produce ribosomally antimicrobial peptides. In bacteria, such compounds are referred to as bacteriocins. The history of bacteriocins goes back to the early 1920s. One has experienced many disappointments in the efforts how to put these compounds into practical use despite being one of the most promising groups of antimicrobial agents to fight bacterial pathogens. However, today, we see new possibilities how to take advantage of such peptides for the benefit of man and animals. Bacteriocin production has become an important property of probiotic bacteria, and targeted use of bacteriocins to fight certain pathogens may have a future.

  2. Cloning of Lab Gene Encoding Bacteriocin From Pediococcus acidilactici Fil Into Escherichia coli DH5a

    OpenAIRE

    Margono, Sebastian; Wijaya, Agus; Rahayu, Endang S.

    2017-01-01

    Pediococcus acidilactici F11 is able to inhibit the growth of related species of enterobacteriaceae by secreting bacteriocin. Effort to increase bacteriocin production by transforming lab gene encoding bacteriocin from P. acidilactici Fl 1 into E. colt DH5a was carried out. Plasmid pPAF11 (encoding bacteriocin from P. acidilactici F11) and p13C19 as vector which were double-digested with Madill and BamHI, ligated, and transformed into E. colt DH5a. White colonies, as indicator of transformant...

  3. Development and characterization of an active polyethylene film containing Lactobacillus curvatus CRL705 bacteriocins.

    Science.gov (United States)

    Blanco Massani, M; Fernandez, M R; Ariosti, A; Eisenberg, P; Vignolo, G

    2008-11-01

    The development and characterization of a bacteriocin-containing polyethylene-based film is described, incorporating lactocin 705 and lactocin AL705, produced by Lactobacillus curvatus CRL705, and nisin. Three different procedures to obtain lactocin 705 and AL705 solution were evaluated, with the partially purified aqueous bacteriocin solution showing the highest inhibitory activity against indicator strains (Lactobacillus plantarum CRL691 and Listeria innocua 7). Pouch contact, soaking and a contact method were compared for incorporating bacteriocins onto PE-based films. Contact between the PE film and bacteriocin solution was the most effective, resulting in a more uniform distribution of bacteriocins on the film surface and using less active solution. The minimal inhibitory concentration of bacteriocin solution was 267 AU cm(-3) (lactocin 705) and 2133 AU cm(-3) (lactocin AL705), while the minimal contact time was 1 h. When relative inhibition area for antilisterial activity of the active films was compared, those treated with L. curvatus CRL705 bacteriocins displayed higher inhibitory activity than nisin-treated films. Functional properties of active PE-films containing lactocin 705 and AL705 showed no differences compared with non-active control films. Bacteriocin-active PE-based films are shown to be highly effective in inhibiting growth of Listeria. The potential use of commercially available packaging films as bacteriocins carriers may benefit active-packaging systems.

  4. Bacteriocin production by indigenous marine catfish associated Vibrio spp.

    Science.gov (United States)

    Zai, Arsalan Saeed; Ahmad, Samia; Rasool, Sheikh Ajaz

    2009-04-01

    Fifty strains of genus Vibrio were isolated (identified) from healthy and diseased marine catfish(es). The isolates were screened for bacteriocin (vibriocin) production. About 32% isolates were found bacteriocin producers. The best producer was identified as Vibrio anguillarum AVP10. The maximum production of vibriocin AVP10 was manifested at 29 degrees C at pH 7, after 18-20 h of incubation. Vibriocin activity was enhanced in the presence of citrate-phosphate buffer. The vibriocin AVP10 withstands autoclaving temperature and showed activity even after prolonged chloroform treatment. Proteolytic enzymes inhibited its activity, while lipolytic enzyme had no effect. It was found bioactive only against intrageneric bacterial strains. Mode of action of vibriocin AVP10 varies with the indicator (sensitive) culture used i.e. bactericidal effects was exerted against V. anguillarum AVS9 while bacteriostatic effect was shown against entero-toxigenic E. coli.

  5. Optimization of Fermentation Conditions for the Production of Bacteriocin Fermentate

    Science.gov (United States)

    2015-03-30

    biopreservation and has been a common practice for centuries (Ross et al., 2002). BAC produced by lactic acid bacteria (LAB) offer several desirable properties...Rua Luisa, M., Pastrana, L. 2001. Nutritional factors affecting the production of two bacteriocins from lactic acid bacteria on whey. Int’ J. Food...items. BAC are an abundant and diverse group of ribosomally synthesized antimicrobial peptides produced by bacteria . They are generally recognized as

  6. Examination of Lactic Acid Bacteria to Secretion of Bacteriocins

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    Maira Urazova

    2014-01-01

    Full Text Available Introduction: Bacteriocins produced by lactic acid bacteria (LAB have the potential to cover a very broad field of applications, including the food industry and the medical sector. In the food industry, bacteriocinogenic LAB strains can be used as starter cultures, co-cultures, and bioprotective cultures, which would be used to improve food quality and safety. In the medical sector, bacteriocins of probiotic LAB might play a role in interactions, which take place in human gastrointestinal tract, and contribute to gut health. The aim of this study was the examine the effect of LAB antimicrobial activity. Methods: LAB were isolated from different commercial and home made products, such as kazy and sour cream. To screen for bacteriocin producing LAB, we used an agar diffusion bioassay, described in a previous study by Dr. Yang, with three modifications in cell-free supernatant (CFS. First we had a clear supernatant, second we adjusted the CFS to pH 6.0 to eliminate acids antimicrobial effects, and third the CFS pH 6.0 was treated with catalase to exclude the action of H2O2 and confirm action of bacteriocin-like substances. Pathogenic S.marcescens, E. coli, S.aureus cultures were used as indicators. Results: Screening of 95 strains of LAB through deferred antagonism to six indicator cultures showed that all of the selected strains had a high value of antibacterial activity. However, CFS of only 50 strains retained their antimicrobial activity, and 10 of them lost this activity in the second modification of CFS with pH 6.0 to test culture S.marcescens, which confirmed the acidic nature of antimicrobial activity of CFS. Lb.rhamnosus (P-1, Lb.fermentum (N-6, and Lc.lactis (7M lost antibacterial activity in the presence of the catalase. All modifications of CFS of three strains: Lb.pentosus (16al, Lb.pentosus (P-2, and Pediococcusacidilactici (8 retained inhibitory activity to E.coli and S. aureus. Supernatants of only Lactococcusgarvieae (10a and

  7. Bacteriocin small of fast-growing rhizobia is chloroform soluble and is not required for effective nodulation

    NARCIS (Netherlands)

    van Brussel, A. A.; Zaat, S. A.; Wijffelman, C. A.; Pees, E.; Lugtenberg, B. J.

    1985-01-01

    Small bacteriocin is a low-molecular-weight bacteriocin which is common in fast-growing rhizobia. As its activity could not be detected in chloroform-sterilized culture supernatants (P.R. Hirsch, J. Gen. Microbiol. 113:219-228, 1979), the bacteriocin could not be purified in order to study its

  8. Antagonistic activity expressed by Shigella sonnei: identification of a putative new bacteriocin

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    Mireille Angela Bernardes Sousa

    2013-09-01

    Full Text Available Bacteriocins are antibacterial, proteinaceous substances that mediate microbial dynamics. Bacteriocin production is a highly disseminated property among all major lineages of bacteria, including Shigella. In this paper, we addressed the purification and characterisation of a bacteriocin produced by a Shigella sonnei strain (SS9 isolated from a child with acute diarrhoea. The substance was purified through ammonium-sulphate precipitation and sequential steps of chromatography. The intracellular fraction obtained at 75% ammonium sulphate maintained activity following exposure to pH values from 1-11 and storage at -80ºC for more than two years and was inactivated by high temperatures and proteases. The molecular mass of the purified bacteriocin was determined by mass spectrometry to be 18.56 kDa. The N-terminal sequence of the bacteriocin did not match any other antibacterial proteins described. A putative new bacteriocin produced by S. sonnei has been detected. This bacteriocin may represent a newly described protein or a previously described protein with a newly detected function. Considering that SS9 expresses antagonism against other diarrhoeagenic bacteria, the bacteriocin may contribute to S. sonnei virulence and is potentially applicable to either preventing or controlling diarrhoeal disease.

  9. Effects of Streptococcus sanguinis Bacteriocin on Cell Surface Hydrophobicity, Membrane Permeability, and Ultrastructure of Candida Thallus

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    Shengli Ma

    2015-01-01

    Full Text Available Candida albicans (C.a and Candida tropicalis (C.t were treated with Streptococcus sanguinis bacteriocin (S.s bacteriocin, respectively; the bacteriostatic dynamics of S.s bacteriocin, their effects on cell surface hydrophobicity, leakage of inorganic phosphorus and macromolecular substance, cytosolic calcium concentration, and ultrastructure changes of Candida thallus were detected and analyzed. The results showed that inhibitory effect of S.s bacteriocin on C.a and C.t reached peak level at 24 h, the cell-surface hydrophobicity decreased significantly (P < 0.05 after S.s bacteriocin treatment, and there was leakage of cytoplasmic inorganic phosphorus and macromolecular substance from C.a and C.t; cytosolic calcium concentration decreased greatly. After 24 h treatment by S.s bacteriocin, depressive deformity and defect could be found in the cell surface of C.a and C.t; the thallus displayed irregular forms: C.a was shrunken, there was unclear margins abutting upon cell wall and cell membrane, nucleus disappeared, and cytoplasm was inhomogeneous; likewise, C.t was first plasmolysis, and then the cytoplasm was shrunk, the ultrastructure of cell wall and cell membrane was continuously damaged, and the nucleus was karyolysis. It was illustrated that S.s bacteriocin had similar antifungal effect on C.a and C.t; their cell surface hydrophobicity, membrane permeability, and ultrastructure were changed significantly on exposure to S.s bacteriocin.

  10. Incidence of Bacteriocins Produced by Food-Related Lactic Acid Bacteria Active towards Oral Pathogens

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    Konstantinos Papadimitriou

    2013-02-01

    Full Text Available In the present study we investigated the incidence of bacteriocins produced by 236 lactic acid bacteria (LAB food isolates against pathogenic or opportunistic pathogenic oral bacteria. This set of LAB contained several strains (≥17% producing bacteriocins active against food-related bacteria. Interestingly only Streptococcus macedonicus ACA-DC 198 was able to inhibit the growth of Streptococcus oralis, Streptococcus sanguinis and Streptococcus gordonii, while Lactobacillus fermentum ACA-DC 179 and Lactobacillus plantarun ACA-DC 269 produced bacteriocins solely against Streptococcus oralis. Thus, the percentage of strains that were found to produce bacteriocins against oral bacteria was ~1.3%. The rarity of bacteriocins active against oral LAB pathogens produced by food-related LAB was unexpected given their close phylogenetic relationship. Nevertheless, when tested in inhibition assays, the potency of the bacteriocin(s of S. macedonicus ACA-DC 198 against the three oral streptococci was high. Fourier-transform infrared spectroscopy combined with principal component analysis revealed that exposure of the target cells to the antimicrobial compounds caused major alterations of key cellular constituents. Our findings indicate that bacteriocins produced by food-related LAB against oral LAB may be rare, but deserve further investigation since, when discovered, they can be effective antimicrobials.

  11. Screening and characterisation of bacteriocin-producing bacteria capable of inhibiting the growth of bovine mastitis

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    Piyanuch Niamsup

    2009-01-01

    Full Text Available A total of 302 bacterial strains were isolated from 43 raw milk samples collected from dairy farms in Chiang Mai province. Out of these strains isolated, three strains were found to produce bacteriocins against Streptococcus dysgalactiae DMST10953, a bovine mastitis pathogen. These were Lactobacillus fermentum RMM701, Streptococcus bovis RMM703 and Streptococcus bovis RMM902, which exhibited bacteriocin activity at 40, 40 and 20 AU/ml respectively. Bacteriocins produced by these three strains were heat-stable up to 80 oC. Bacteriocins produced by L. fermentum RMM701 and S. bovis RMM902 were stable at pH 2.0 - 7.0 while that from S. bovis RMM703 was stable at pH 2.0 - 6.0. These bacteriocins were also found to be inactivated by proteolytic enzymes such as proteinase K and subtilisin A.

  12. THE IMPORTANCE OF BACTERIOCINS IN MEAT AND MEAT PRODUCTS

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    Meltem SERDAROĞLU

    2000-03-01

    Full Text Available There is an increasing consumer demand for food products which are free of chemical additives, reduced in salt and processed as little as possible. These minimally processed foods require special application to assure their microbiological safety. The use of microorganisms and enzymes for food preservatives is called biopreservation. The most important group of microorganisms with antimicrobial effect used in the production of foods is the lactic acid bacteria. In meats although lactic acid bacteria constitue apart of the initial microflora, they become dominant during the processing of meats. In this research bacteriocins of lactic acid bacteria and their usage in meat and meat products for biopreservation are discussed.

  13. Bacteriocins: exploring alternatives to antibiotics in mastitis treatment

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    Reneé Pieterse

    2010-10-01

    Full Text Available Mastitis is considered to be the most costly disease affecting the dairy industry. Management strategies involve the extensive use of antibiotics to treat and prevent this disease. Prophylactic dosages of antibiotics used in mastitis control programmes could select for strains with resistance to antibiotics. In addition, a strong drive towards reducing antibiotic residues in animal food products has lead to research in finding alternative antimicrobial agents. In this review we have focus on the pathogenesis of the mastitis in dairy cows, existing antibiotic treatments and possible alternative for application of bacteriocins from lactic acid bacteria in the treatment and prevention of this disease.

  14. Bacteriocin activity against various pathogens produced by Pediococcus pentosaceus VJ13 isolated from Idly batter.

    Science.gov (United States)

    Vidhyasagar, Venkatasubramanian; Jeevaratnam, Kadirvelu

    2013-11-01

    Bacteriocins, an antimicrobial peptide, is known to have wide spectrum antimicrobial activity against various pathogens. Because they are easily digested in the intestine, they are considered as safe and are widely used as food preservatives. Hence their purification and characterization have attracted considerable attraction, especially for those having activity against human pathogens. In this study, the bacteriocin produced by Pediococcus pentosaceus VJ13 was precipitated with cold acetone and purified by gel permeation chromatography and hydrophobic interaction chromatography. The bacteriocin exhibited antimicrobial activity against various pathogens, like Mycobacterium smegmatis, Klebsiella pneumonia, Clostridium perfringens and Staphylococcus epidermidis. The activity of bacteriocin was lost completely after treatment with protease, which revealed its proteinaceous nature. The bacteriocin was stable up to 100°C and exhibited antilisterial property which is a characteristic feature of class IIa bacteriocins. It was active within the pH range of 2-8 and stable against various chemicals and denaturants. Tricine SDS-PAGE revealed its molecular weight to be 4.0 kDa, where the corresponding activity against Listeria monocytogenes was also noted. Treatment of L. monocytogenes with bacteriocin decreased the viable cell count, and scanning electron microscope analysis revealed membrane pore formation that resulted in the release of intracellular content, suggesting its bactericidal effect. Copyright © 2013 John Wiley & Sons, Ltd.

  15. Pediocins: The bacteriocins of Pediococci. Sources, production, properties and applications

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    Anastasiadou Sofia

    2009-01-01

    Full Text Available Abstract Class IIa bacteriocins from lactic acid bacteria are small, cationic proteins with antilisterial activity. Within this class, the pediocins are those bacteriocins that share a highly conserved hydrophilic and charged N-terminal part harboring the consensus sequence -YGNGV- and a more variable hydrophobic and/or amphiphilic C-terminal part. Several pediocins have been isolated and characterized. Despite the structural similarities, their molecular weight varies, as well as their spectrum of antimicrobial activity. They exhibit important technological properties, e.g. thermostability and retaining of activity at a wide pH range, which along with the bactericidal action against Gram-positive food spoilage and pathogenic bacteria, make them an important class of biopreservatives. Much new information regarding the pediocins has emerged during the last years. In this review, we summarize and discuss all the available information regarding the sources of pediocins, the characteristics of their biosynthesis and production in fermentation systems, the characteristics of the known pediocin molecules, and their antibacterial action. The advances made by genetic engineering in improving the features of pediocins are also discussed, as well as their perspectives for future applications.

  16. Bacteriocin-Producing Lactic Acid Bacteria Isolated from Traditional Fermented Food

    Science.gov (United States)

    Kormin, Salasiah; Rusul, Gulam; Radu, Son; Ling, Foo Hooi

    2001-01-01

    Lactic Acid Bacteria (LAB) isolated from several traditional fermented foods such as “tempeh”, “tempoyak” and “tapai” were screened for the production of bacteriocin. One strain isolated from “tempeh” gives an inhibitory activity against several LAB. The strain was later identified as Lactobacillus plantarum BS2. Study shows that the inhibitory activity was not caused by hydrogen peroxide, organic acids or bacteriophage. The bacteriocin production was maximum after 10 hours of incubation with an activity of 200 AU/ml. The bacteriocin was found to be sensitive towards trypsin, α-chymotrypsin, β-chymotrypsin, α-amylase and lysozyme. PMID:22973159

  17. Purification Techniques of Bacteriocins from Lactic Acid Bacteria and Other Gram-Positive Bacteria

    Science.gov (United States)

    Saavedra, Lucila; Sesma, Fernando

    The search for new antimicrobial peptides produced by lactic acid ­bacteria and other Gram-positive microorganisms has become an interesting field of research in the past decades. The fact that bacteriocins are active against numerous foodborne and human pathogens, are produced by generally regarded as safe (GRAS) microorganisms, and are readily degraded by proteolytic host systems makes them attractive candidates for biotechnological applications. However, before suggesting or choosing a new bacteriocin for future technology developments, it is necessary to elucidate its biochemical structure and its mode of action, which may be carried out once the bacteriocin is purified to homogeneity. This chapter focuses on describing the main strategies used for the purification of numerous bacteriocins.

  18. Production, Purification, Stability and Efficacy of Bacteriocin from Isolates of Natural Lactic Acid Fermentation of Vegetables

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    Vinod Kumar Joshi

    2006-01-01

    Full Text Available The antimicrobial activity of partially purified bacteriocin produced during natural lactic acid fermentation of carrot, radish and cucumber was assessed and characterized. Out of ten strains, the isolated strain CA 44 of Lactobacillus genus from carrot fermentation produced bacteriocin with maximum antimicrobial activity against Escherichia coli, Staphylococcus aureus and Bacillus cereus, though it was more effective against E. coli than others. Bacteriocin was stable at up to 100 °C but its activity declined compared to that at 68 °C and was completely lost at 121 °C. The maximum antimicrobial activity was retained within the pH range of 4–5, but it was adversely affected by the addition of papain. Bacteriocin was also effective against B. cereus in different fruit products (pulp, juice and wine indicating its potential application as a biopreservative in fruit products.

  19. 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

  20. Importance in dairy technology of bacteriocins produced by dairy starter cultures

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    Bedia Şimşek

    2002-03-01

    Full Text Available Bacteriocins produced by Lactic acid bacteria (LAB and propionic acid bacteria (PAB are heterogeneous group of peptide inhibitors which include lantibiotics (class I, e. g. nisin, small heat-stable peptides (class II, e. g. pediocin PA-1 and large heat-labile proteins (class III, e. g. helveticin J. Many bacteriocins belonging to the first two groups can be successfully used to inhibit undesirable microorganisms in foods, but only nisin is produced industrially and is used as a food preservative. LAB and PAB develops easily in milk and milk products. LAB and PAB growth in dairy products can cause microbial interference to spoilage and pathogenic bacteria through several metabolits, specially bacteriocins. The review deals with the description of milk-borne bacteriocins and their application in milk and milk products either to extend the shelf life or to inhibit milk pathogens.

  1. Genetic analysis of acidocin B : a novel bacteriocin produced by Lactobacillus acidophilus

    NARCIS (Netherlands)

    Leer, R.J.; Vossen, J.M.B.M. van der; Giezen, M. van; Noort, J.M. van; Pouwels, P.H.

    1995-01-01

    The genes encoding the production of acidocin B, a bacteriocin produced by Lactobacillus acidophilus strain M46 which is active against Listeria monocytogenes, Clostridium sporogenes, Brochothrix thermosphacta, Lactobacillus fermentum and Lactobacillus delbrueckii subsp. bulgaricus, but inactive

  2. Bacteriocins from lactic acid bacteria and their potential in the preservation of fruit products.

    Science.gov (United States)

    Barbosa, Ana Andréa Teixeira; Mantovani, Hilário Cuquetto; Jain, Sona

    2017-11-01

    Bacteriocins produced by lactic acid bacteria (LAB) are well-recognized for their potential as natural food preservatives. These antimicrobial peptides usually do not change the sensorial properties of food products and can be used in combination with traditional preservation methods to ensure microbial stability. In recent years, fruit products are increasingly being associated with food-borne pathogens and spoilage microorganisms, and bacteriocins are important candidates to preserve these products. Bacteriocins have been extensively studied to preserve foods of animal origin. However, little information is available for their use in vegetable products, especially in minimally processed ready-to-eat fruits. Although, many bacteriocins possess useful characteristics that can be used to preserve fruit products, to date, only nisin, enterocin AS-48, bovicin HC5, enterocin 416K1, pediocin and bificin C6165 have been tested for their activity against spoilage and pathogenic microorganisms in these products. Among these, only nisin and pediocin are approved to be commercially used as food additives, and their use in fruit products is still limited to certain countries. Considering the increasing demand for fresh-tasting fruit products and concern for public safety, the study of other bacteriocins with biochemical characteristics that make them candidates for the preservation of these products are of great interest. Efforts for their approval as food additives are also important. In this review, we discuss why the study of bacteriocins as an alternative method to preserve fruit products is important; we detail the biotechnological approaches for the use of bacteriocins in fruit products; and describe some bacteriocins that have been tested and have potential to be tested for the preservation of fruit products.

  3. Microcins from Enterobacteria: On the Edge Between Gram-Positive Bacteriocins and Colicins

    Science.gov (United States)

    Rebuffat, Sylvie

    Most bacteria and archaea produce gene-encoded antimicrobial peptides/proteins called bacteriocins, which are secreted by the producing bacteria to compete against other microorganisms in a given niche. They are considered important mediators of intra- and interspecies interactions and therefore a factor in ­maintaining the microbial diversity and stability. They are ribosomally synthesized, and most of them are produced as inactive precursor proteins, which in some cases are further enzymatically modified. Bacteriocins generally exert potent antibacterial activities directed against bacterial species closely related to the producing bacteria. Bacteriocins are abundant and diverse in Gram-negative and Gram-positive bacteria. This chapter focuses on colicins and microcins from enterobacteria (mainly Escherichia coli) and on bacteriocins from lactic acid bacteria (LAB). Microcins are the lower-molecular-mass bacteriocins produced by Gram-negative bacteria with a repertoire of only 14 representatives. They form a very restricted family of bacteriocins, compared to the huge family of LAB bacteriocins that is constituted of several hundreds of peptides, with which microcins share common characteristics. Nevertheless, microcins also show similarities, particularly in their uptake mechanisms, with the higher-molecular-mass colicins, also produced by E. coli strains. On the edge between LAB bacteriocins and colicins, microcins appear to combine highly efficient strategies developed by both Gram-positive and Gram-negative bacteria at different levels, including uptake, translocation, killing of target cells, and immunity of the producing bacteria, making them important actors of bacterial competitions and fascinating models for novel concepts toward antimicrobial strategies and against resistance mechanisms.

  4. Production of bacteriocin by Leuconostoc mesenteroides 406 isolated from Mongolian fermented mare's milk, airag.

    Science.gov (United States)

    Wulijideligen; Asahina, Takayuki; Hara, Kazushi; Arakawa, Kensuke; Nakano, Hiroyuki; Miyamoto, Taku

    2012-10-01

    The purification and characterization of a bacteriocin produced by Leuconostoc mesenteroides strain 406 that was isolated from traditional Mongolian fermented mare's milk, airag, were carried out. Leuconostoc mesenteroides strain 406 was identified on the basis of its morphological and biochemical characteristics and carbohydrate fermentation profile and by API 50 CH kit and 16S ribosomal DNA analyses. The neutral-pH cell-free supernatant of this bacterium inhibited the growth of several lactic acid bacteria and food spoilage and pathogenic organisms, including Listeria monocytogenes and Clostridium botulinum. The bacteriocin was heat-stable and not sensitive to acid and alkaline conditions, but was sensitive to several proteolytic enzymes such as pepsin, pronase E, proteinase K, trypsin, and α-chymotrypsin, but not catalase. Optimum bacteriocin production (4000 activity units/mL) was achieved when the strain was cultured at 25°C for 24-36 h in Man Rogosa Sharpe medium. The bacteriocin was partially purified by ammonium sulfate precipitation (80% saturation), dialysis (cut-off MW: 1000), and gel filtration chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that the bacteriocin had a molecular weight of approximately 3.3 kDa. To our knowledge, this is the first report of the isolation of a bacteriocin-producing Leuconostoc strain from airag. An application to fermented milks would be desired. © 2012 The Authors. Animal Science Journal © 2012 Japanese Society of Animal Science.

  5. Bacteriocins produced by L. fermentum and L .acidophilus can inhibit cephalosporin resistant E .coli.

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    Saba Riaz

    2010-10-01

    Full Text Available Reemerging infections occur due to resistant bacteria. Such infections create restrictions for clinicians and microbiologists in drug selection. Such problems demand new strategies for solution. Use of bacteriocins for this purpose may be fruitful. In the present research work, the inhibitory effects of bactericins on cephalosporin resistant Escherichia coli are used as model system for the control of antibiotic resistant pathogenic bacteria. Cephalosporin resistant Escherichia coli strain was isolated from pus by using conventional methodology. For bacteriocin production, Lactobacilli strains were selected by using selective media. Out of seventy two strains isolated from yogurt, fecal materials of human, chick, parrot and cat, only two strains (strain 45 and strain 52 were found to produce bacteriocins having antimicrobial potential against cephalosporin resistant Escherichia coli. Biochemical characterization showed that strain 45 belonged to group of Lactobacillus fermentum and strain 52 to Lactobacillus acidophilus. Both strains showed maximum growth at 25°C and 35°C respectively. Suitable pH was 5.5 and 6.0 for Lactobacillus fermentum and Lactobacillus acidophilus respectively. Bacteriocins produced by both strains were found stable at 50, 75 and 100°C for 60min. Function of bacteriocin was also not disturbed due to change in pH. These findings suggest that bacteriocin produced by Lactobacillus fermentum and Lactobacillus acidophilus can be used for the infection control of cephalosporin resistant Escherichia coli.

  6. Optimization and partial characterization of bacteriocin produced by Lactobacillus bulgaricus -TLBFT06 isolated from Dahi.

    Science.gov (United States)

    Mahmood, Talat; Masud, Tariq; Ali, Sartaj; Abbasi, Kashif Sarfraz; Liaquat, Muhammad

    2015-03-01

    Lactobacillus bulgaricus is one of the predominant lactic acid bacteria of dahi, conferring technological and functional attributes. In the present study thirty dahi samples were investigated for bacteriocin producing L. bulgaricus. Fourteen different isolates were obtained and five were scrutinized for antibacterial activities against food born pathogens. Amongst, a strain TLB06FT was found to have a wide array of antibacterial activities against Gram positive and negative bacteria was selected for further characterization. Growth media optimization for this strain revealed maximum bacteriocin production on MRS media supplemented with glucose (2%), sodium chloride (1%), Tween-80 (0.5%) and yeast extract (1 %). In addition, optimization of growth conditions revealed maximum bacteriocin production at pH 5.5 and temperature of 30-37°C. Bacteriocin showed thermo stability at 90°C and remained highly active in the pH range of 3.5-7.5, inactive by protein catalyzing enzymes and showed no change in activity (800AumL(-1)) when treated with organic solvents and surfactants. The obtained bacteriocin was purified to 1600AU mL(-1) by ammonium sulfate precipitation (80%) by using dialyzing tubing. In the same way, a single peak was obtained by RP-HPLC having antibacterial activity of 6400AU mL(-1). Thus, wild strains of L. bulgaricus have great potential for the production new and novel type of bacteriocins.

  7. Thermostable Bacteriocin BL8 from Bacillus licheniformis isolated from marine sediment.

    Science.gov (United States)

    Smitha, S; Bhat, S G

    2013-03-01

    To isolate and characterize bacteriocin, BL8, from the bacteria identified as Bacillus licheniformis from marine environment. One-hundred and twelve bacterial isolates from sediment and water samples collected off the coast of Cochin, India, were screened for antibacterial activity. Strain BTHT8, identified as Bacillus licheniformis, inhibited the growth of Gram-positive test organisms. The active component labelled as bacteriocin BL8 was partially purified by ammonium sulphate fractionation and was subjected to glycine SDS-PAGE. The band exhibiting antimicrobial activity was electroeluted and analysed using MALDI-TOF mass spectrometry, and the molecular mass was determined as 1.4 kDa. N-terminal amino acid sequencing of BL8 gave a 13 amino acid sequence stretch. Bacteriocin BL8 was stable even after boiling at 100 °C for 30 min and over a wide pH range of 1-12. A novel, pH-tolerant and thermostable bacteriocin BL8, active against the tested Gram-positive bacteria, was isolated from Bacillus licheniformis. This study reports a stable, low molecular weight bacteriocin from Bacillus licheniformis. This bacteriocin can be used to address two important applications: as a therapeutic agent and as a biopreservative in food processing industry. © 2012 The Society for Applied Microbiology.

  8. Typing of Enterobacter spp. by bacteriocin susceptibility and its use in epidemiological analysis.

    Science.gov (United States)

    Bauernfeind, A; Petermüller, C

    1984-01-01

    Most clinical isolates of Enterobacter cloacae are bacteriocinogenic and susceptible to bacteriocins. Both rapidly diffusing, nonsedimentable, protease-susceptible and slowly diffusing, sedimentable, protease-resistant bacteriocins are produced. A practicable system was devised for epidemiological typing of E. cloacae isolates by their patterns of susceptibility to bacteriocins. A set of eight bacteriocin-producing strains was grown on tryptic soy agar plates for 16 h. After removal of the producer lawn, the isolates to be typed were inoculated on the agar media by a multipoint inoculator. After a second 16-h period of incubation, the strains were classified into bacteriocin types according to the patterns of growth inhibition. Typability of 134 clinical isolates was 96.3%. Only 11 (8.2%) of the isolates fell into the largest group. Repeat testing of isolates from the same patients within 2 months gave identical bacteriocin types. Other species of Enterobacter (E. agglomerans and E. aerogenes) are also typable by this method. Images PMID:6746888

  9. Elimination of Listeria monocytogenes in sausage meat by combination treatment: Radiation and radiation-resistant bacteriocins

    Science.gov (United States)

    Turgis, Mélanie; Stotz, Viviane; Dupont, Claude; Salmieri, Stéphane; Khan, Ruhul A.; Lacroix, Monique

    2012-08-01

    Two new bacteria were isolated from human feces and were designated MT 104 and MT 162. They were able to produce bacteriocins that are active against five strains of Listeria monocytogenes. Bacteriocins produced by these isolated strains had 100% and 82.35% residual activity when they were treated by gamma radiation at doses of 4 and 40 kGy, respectively. A reduction of 1.0, 1.5 and 3 log CFU/g of L. monocytogenes was observed in sausage meat when treated with bacteriocins from MT 104, MT 162, and nisin, respectively. For synergic effect, the D10 value in presence of the bacteriocins produced by MT 104 showed a 1.08 fold increased relative sensitivity of L. monocytogenes as compared to control after 5 days. The highest synergic effect was observed in presence of nisin which led to 1.61 fold increased relative sensitivity. Combined treatments with nisin and γ-irradiation showed a synergic antimicrobial effect in meat after 24 h and 5 days of storage. A synergic effect was observed only after 5 days at 4 °C for the bacteriocin from MT 104, as compared to the bacteriocin produced by MT 162 that had only an additive antimicrobial effect in all conditions.

  10. 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.

  11. Production and Characterization of Bacteriocin Produced by Lactobacillus Viridescence(NICM 2167

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    Sure KP

    Full Text Available The present study focused on the production optimization of bacteriocin by Lactobacillus viridescence NICM 2167 followed by its purification and characterization. The bacteriocins are antimicrobial peptides produced by many Gram positive and Gram negative bacteria.The bacteriocin produced by LAB (lactic acid bacteria received attention in recent years due to their potential application as natural preservatives in food. Bacteriocinproduced by Lactobacillus viridescence showed broad range of antimicrobial activity against food borne pathogens. Production parameters were optimized showing highest production of bacteriocinin MRS broth with pH= 7.0 incubated at 37°C for 48 h. Bacteriocin was purified in two steps involving ammonium sulphate precipitation followed by gel filtration using Sephadex G-100. Purified bacteriocin with single band on SDS-PAGE showed molecular weight of 8.3 kDa. This purified bacteriocin was stable over wide range of pH (4-10 as well as temperatures (4°C-121°C suggesting it as a potent candidate for preservation of various foods.

  12. The structure of pyogenecin immunity protein, a novel bacteriocin-like immunity protein from Streptococcus pyogenes

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    Volkart Lour

    2009-12-01

    Full Text Available Abstract Background Many Gram-positive lactic acid bacteria (LAB produce anti-bacterial peptides and small proteins called bacteriocins, which enable them to compete against other bacteria in the environment. These peptides fall structurally into three different classes, I, II, III, with class IIa being pediocin-like single entities and class IIb being two-peptide bacteriocins. Self-protective cognate immunity proteins are usually co-transcribed with these toxins. Several examples of cognates for IIa have already been solved structurally. Streptococcus pyogenes, closely related to LAB, is one of the most common human pathogens, so knowledge of how it competes against other LAB species is likely to prove invaluable. Results We have solved the crystal structure of the gene-product of locus Spy_2152 from S. pyogenes, (PDB:2fu2, and found it to comprise an anti-parallel four-helix bundle that is structurally similar to other bacteriocin immunity proteins. Sequence analyses indicate this protein to be a possible immunity protein protective against class IIa or IIb bacteriocins. However, given that S. pyogenes appears to lack any IIa pediocin-like proteins but does possess class IIb bacteriocins, we suggest this protein confers immunity to IIb-like peptides. Conclusions Combined structural, genomic and proteomic analyses have allowed the identification and in silico characterization of a new putative immunity protein from S. pyogenes, possibly the first structure of an immunity protein protective against potential class IIb two-peptide bacteriocins. We have named the two pairs of putative bacteriocins found in S. pyogenes pyogenecin 1, 2, 3 and 4.

  13. The structure of pyogenecin immunity protein, a novel bacteriocin-like immunity protein from streptococcus pyogenes.

    Energy Technology Data Exchange (ETDEWEB)

    Chang, C.; Coggill, P.; Bateman, A.; Finn, R.; Cymborowski, M.; Otwinowski, Z.; Minor, W.; Volkart, L.; Joachimiak, A.; Wellcome Trust Sanger Inst.; Univ. of Virginia; UT Southwestern Medical Center

    2009-12-17

    Many Gram-positive lactic acid bacteria (LAB) produce anti-bacterial peptides and small proteins called bacteriocins, which enable them to compete against other bacteria in the environment. These peptides fall structurally into three different classes, I, II, III, with class IIa being pediocin-like single entities and class IIb being two-peptide bacteriocins. Self-protective cognate immunity proteins are usually co-transcribed with these toxins. Several examples of cognates for IIa have already been solved structurally. Streptococcus pyogenes, closely related to LAB, is one of the most common human pathogens, so knowledge of how it competes against other LAB species is likely to prove invaluable. We have solved the crystal structure of the gene-product of locus Spy-2152 from S. pyogenes, (PDB: 2fu2), and found it to comprise an anti-parallel four-helix bundle that is structurally similar to other bacteriocin immunity proteins. Sequence analyses indicate this protein to be a possible immunity protein protective against class IIa or IIb bacteriocins. However, given that S. pyogenes appears to lack any IIa pediocin-like proteins but does possess class IIb bacteriocins, we suggest this protein confers immunity to IIb-like peptides. Combined structural, genomic and proteomic analyses have allowed the identification and in silico characterization of a new putative immunity protein from S. pyogenes, possibly the first structure of an immunity protein protective against potential class IIb two-peptide bacteriocins. We have named the two pairs of putative bacteriocins found in S. pyogenes pyogenecin 1, 2, 3 and 4.

  14. Characterization of a new bacteriocin, Carocin D, from Pectobacterium carotovorum subsp. carotovorum Pcc21.

    Science.gov (United States)

    Roh, Eunjung; Park, Tae-Ho; Kim, Myung-Il; Lee, Seungdon; Ryu, Sangryeol; Oh, Chang-Sik; Rhee, Sangkee; Kim, Doo-Ho; Park, Beom-Seok; Heu, Sunggi

    2010-11-01

    Two different bacteriocins, carotovoricin and carocin S1, had been found in Pectobacterium carotovorum subsp. carotovorum, which causes soft-rot disease in diverse plants. Previously, we reported that the particular strain Pcc21, producing only one high-molecular-weight bacteriocin, carried a new antibacterial activity against the indicator strain Pcc3. Here, we report that this new antibacterial activity is due to a new bacteriocin produced by strain Pcc21 and named carocin D. Carocin D is encoded by the caroDK gene located in the genomic DNA together with the caroDI gene, which seems to encode an immunity protein. N-terminal amino acid sequences of purified carocin D were determined by Edman degradation. In comparison with the primary translation product of caroDK, it was found that 8 amino acids are missing at the N terminus. This finding proved that carocin D is synthesized as a precursor peptide and that 8 amino acids are removed from its N terminus during maturation. Carocin D has two putative translocation domains; the N-terminal and C-terminal domains are homologous to those of Escherichia coli colicin E3 and Pseudomonas aeruginosa S-type pyocin, respectively. When caroDK and caroDI genes were transformed into carocin D-sensitive bacteria such as Pcc3, the bacteria became resistant to this bacteriocin. Carocin D has one putative DNase domain at the extreme C terminus and showed DNase activity in vitro. This bacteriocin had slight tolerance to heat but not to proteases. The caroDK gene was present in only 5 of 54 strains of P. carotovorum subsp. carotovorum. These results indicate that carocin D is a third bacteriocin found in P. carotovorum subsp. carotovorum, and this bacteriocin can be readily expressed in carocin D-sensitive nonpathogenic bacteria, which may have high potential as a biological control agent in the field.

  15. Characterization of a New Bacteriocin, Carocin D, from Pectobacterium carotovorum subsp. carotovorum Pcc21▿ †

    Science.gov (United States)

    Roh, Eunjung; Park, Tae-Ho; Kim, Myung-il; Lee, Seungdon; Ryu, Sangryeol; Oh, Chang-Sik; Rhee, Sangkee; Kim, Doo-Ho; Park, Beom-Seok; Heu, Sunggi

    2010-01-01

    Two different bacteriocins, carotovoricin and carocin S1, had been found in Pectobacterium carotovorum subsp. carotovorum, which causes soft-rot disease in diverse plants. Previously, we reported that the particular strain Pcc21, producing only one high-molecular-weight bacteriocin, carried a new antibacterial activity against the indicator strain Pcc3. Here, we report that this new antibacterial activity is due to a new bacteriocin produced by strain Pcc21 and named carocin D. Carocin D is encoded by the caroDK gene located in the genomic DNA together with the caroDI gene, which seems to encode an immunity protein. N-terminal amino acid sequences of purified carocin D were determined by Edman degradation. In comparison with the primary translation product of caroDK, it was found that 8 amino acids are missing at the N terminus. This finding proved that carocin D is synthesized as a precursor peptide and that 8 amino acids are removed from its N terminus during maturation. Carocin D has two putative translocation domains; the N-terminal and C-terminal domains are homologous to those of Escherichia coli colicin E3 and Pseudomonas aeruginosa S-type pyocin, respectively. When caroDK and caroDI genes were transformed into carocin D-sensitive bacteria such as Pcc3, the bacteria became resistant to this bacteriocin. Carocin D has one putative DNase domain at the extreme C terminus and showed DNase activity in vitro. This bacteriocin had slight tolerance to heat but not to proteases. The caroDK gene was present in only 5 of 54 strains of P. carotovorum subsp. carotovorum. These results indicate that carocin D is a third bacteriocin found in P. carotovorum subsp. carotovorum, and this bacteriocin can be readily expressed in carocin D-sensitive nonpathogenic bacteria, which may have high potential as a biological control agent in the field. PMID:20870796

  16. Characterization of Partially Purified Bacteriocin Like Substance (BLIS Produced by Probiotic Lactobacillus Strains

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    Saeed Ismail Khanian

    2014-05-01

    Full Text Available Background: There is an increasing interest in search for antimicrobial peptides (bacteriocins and bacteriocin-like compounds produced by lactic acid bacteria (LAB because of their potential to be used as antimicrobial agents for improving the safety of food products. Objectives: The main objective of study was to evaluate the antibacterial potential of locally isolated Lactic Acid bacteria (LAB and determine their bacteriocin producing ability in in-vitro conditions. Materials and Methods: The antibacterial activity of 77 isolated LAB strains was tested against a number of pathogens by well-diffusion method. The isolates demonstrating antimicrobial potential were selected and tested for the production of bacteriocin or bacteriocin like substance. The bacteriocin produced by two of the isolates were partially purified and characterized. Results: The results indicated the neutralized supernatant fluid of two of the isolates identified as L. brevis LB32 and L. pentosus LP05, were active against the growth of Listeria monocytogenes, Salmonella enteritidis, Shigella dysenteriae, Staphylococcus aureus and Streptococcus pneumoniae. Additionally, L. brevis LB32 was able to inhibit the growth of Salmonella typhi and Klebsiella pneumoniae, while, S. pnuemoniae and L. monocytogenes appeared to be the most sensitive strain as apparent by highest zone of inhibition against these pathogens, respectively. The antimicrobial activity in the supernatant fluids of the mentioned strains remained unaffected after treating with enzymes catalase, lipase and lysozyme, while were strongly sensitive to the action of proteolytic enzymes, suggesting the presence of bacteriocin like inhibitory substance (BLIS in the two isolates. The inhibitory substance produced by the two isolates appeared heat resistant and tolerated 100˚C and 121˚C for 55 minutes and 20 minutes, respectively. Partial purification of the concentrated culture supernatant fluids of L. brevis LB32 and L

  17. Influence of Growth Medium on Hydrogen Peroxide and Bacteriocin Production of Lactobacillus Strains

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    Edina Németh

    2005-01-01

    Full Text Available This study was conducted to investigate the inhibitory effect of bacteriocin and the production of hydrogen peroxide by four non-starter lactic acid bacteria, Lactobacillus plantarum 2142, Lactobacillus curvatus 2770, Lactobacillus curvatus 2775, Lactobacillus casei subsp. pseudoplantarum 2750 and the probiotic strain Lactobacillus casei Shirota, propagated in de Man Rogosa Sharpe (MRS and tomato juice (TJ broth. The methods were a commonly used agar diffusion technique and a microtiter assay method. The best peroxide-producing Lactobacillus strain was selected for screening the inhibitory activity against Listeria monocytogenes, Bacillus cereus, Escherichia coli and the activity of bacteriocins against Lactobacillus sakei and Candida glabrata. All of the investigated lactic acid bacteria (LAB strains grown in MRS broth produced the highest concentration of hydrogen peroxide ranging from 2–6 g/mL after 72 h of storage. L. plantarum 2142 produced enough hydrogen peroxide already after 24 h at 5 °C in phosphate buffer to inhibit the growth of L. monocytogenes and B. cereus. Crude bacteriocin suspension from the investigated LAB inhibited only slightly the growth of L. sakei, however, the same suspension from MRS completely inhibited the 6-fold diluted yeast suspension. The concentrated bacteriocin suspensions from the both broths inhibited the growth of L. sakei completely. Among the strains, L. plantarum 2142 seemed to be the best peroxide and bacteriocin producer, and the antimicrobial metabolite production was better in MRS than in TJ broth.

  18. A putative amino acid transporter determines sensitivity to the two-peptide bacteriocin plantaricin JK

    NARCIS (Netherlands)

    Oppegård, Camilla; Kjos, Morten; Veening, Jan-Willem; Nissen-Meyer, Jon; Kristensen, Tom

    2016-01-01

    Lactobacillus plantarum produces a number of antimicrobial peptides (bacteriocins) that mostly target closely related bacteria. Although bacteriocins are important for the ecology of these bacteria, very little is known about how the peptides target sensitive cells. In this work, a putative membrane

  19. Chemical and genetic characterization of bacteriocins: antimicrobial peptides for food safety.

    Science.gov (United States)

    Snyder, Abigail B; Worobo, Randy W

    2014-01-15

    Antimicrobial peptides are produced across all domains of life. Among these diverse compounds, those produced by bacteria have been most successfully applied as agents of biocontrol in food and agriculture. Bacteriocins are ribosomally synthesized, proteinaceous compounds that inhibit the growth of closely related bacteria. Even within the subcategory of bacteriocins, the peptides vary significantly in terms of the gene cluster responsible for expression, and chemical and structural composition. The polycistronic gene cluster generally includes a structural gene and various combinations of immunity, secretion, and regulatory genes and modifying enzymes. Chemical variation can exist in amino acid identity, chain length, secondary and tertiary structural features, as well as specificity of active sites. This diversity posits bacteriocins as potential antimicrobial agents with a range of functions and applications. Those produced by food-grade bacteria and applied in normally occurring concentrations can be used as GRAS-status food additives. However, successful application requires thorough characterization. © 2013 Society of Chemical Industry.

  20. Detection of bacteriocins produced by plant pathogenic bacteria from the general Erwinia, Pseudomonas and Xanthomonas

    International Nuclear Information System (INIS)

    Biagi, C.M.R. de

    1992-01-01

    Detection of bacteriocin production was studied under distinct conditions using strains of plant pathogenic bacteria from the genera Erwinia, Pseudomonas and Xanthomonas. 58.06%, 79.31% and 40.00% of producing strains were found respectively in the three groups of bacteria using the 523 medium which was the best for the detection of bacteriocin production. Increasing agar concentrations added to the medium up to 1,5% improved the detection. The amount of medium added to the Petri dishes did not affect bacteriocin production. The longest incubation time (72 h.) improved the detection of haloes production. Ultra-violet irradiation in low dosages seems to improve the visualization of haloes production but this is dependent on the tested strains. (author)

  1. Potential value of bacteriocins in the etiological treatment of infectious diseases of the respiratory tract

    Directory of Open Access Journals (Sweden)

    А.Е. Abaturov

    2017-10-01

    Full Text Available Bacteriocins are ribosomal-synthesized hydrophobic antimicrobial peptides with a broad antimicrobial spectrum of action. Gram-positive bacteria are the main source of bacteriocins. Bacteriocins of different classes acting on Gram-positive and Gram-negative bacteria use different molecular mechanisms, the functioning of which leads to disruption of the integrity of the cell wall or inhibition of the synthesis of nucleic acids and proteins of targeted bacteria. Currently, more than 100 lantibiotic peptides are described in the literature. Many of them are used to develop future medicines. Several lantibiotics are currently undergoing clinical and preclinical trials, including bioengineering lantibiotics, which can play a key role in overcoming the antibiotic resistance of bacterial pathogens.

  2. Partial purification and characterization of a bacteriocin produced by Enterococcus faecium 130 isolated from mozzarella cheese

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    Fabrício Luiz Tulini

    2011-03-01

    Full Text Available Lactic acid bacteria are important in foods as potential probiotics and also due to the ability to produce antimicrobial compounds that can contribute for biopreservation. In this work, the bacteriocin produced by the food isolate Enterococcus faecium 130 was partially purified and characterized. The compound was active against Gram-positive bacteria, including Listeria monocytogenes. It was produced after 4 days of storage at a broad temperature range (4 to 37 °C; it was stable at pH ranging from 2 to 10 with no loss of activity after heating at 100 °C for 15 minutes. Bacteriocin was partially purified by the adsorption-desorption technique, and the analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE showed a molecular mass of 3.5 to 6.5 kDa. These data encourage studies on application of this bacteriocin in food systems as an additional hurdle to microbial growth.

  3. Partial characterization of bacteriocin induced by irradiated and non-irradiated strain of yersinia enterocolitical

    International Nuclear Information System (INIS)

    Awny, N.M.

    1991-01-01

    Twenty isolates of yersinia enterocolitica were tested for the inhibition of the growth of different strains of yersinia. The screening tests revealed three possible bacteriocinogenic strains. One of them was selected for additional studies after it was shown that its inhibitory substances differed in their activity spectra. The gamma irradiated strain lost the ability to produce bacteriocin at 0.6 kGy level. Crude preparation of bacteriocin obtained from the wild strain were not affected by chloroform or other organic solvents but inactivated by trypsin and heating at 80 C for 45 min. Bacteriocin induced by irradiated strain was easily inactivated by thermal treatment. Exposure of agar fragments containing the inhibitory active component to a pH value ranging between 2 to 11 did not affect bactericidal activity.4 tab

  4. Effect of Lactobacillus salivarius bacteriocin Abp118 on the mouse and pig intestinal microbiota.

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    Eliette Riboulet-Bisson

    Full Text Available Lactobacilli are gram-positive bacteria that are a subdominant element in the human gastrointestinal microbiota, and which are commonly used in the food industry. Some lactobacilli are considered probiotic, and have been associated with health benefits. However, there is very little culture-independent information on how consumed probiotic microorganisms might affect the entire intestinal microbiota. We therefore studied the impact of the administration of Lactobacillus salivarius UCC118, a microorganism well characterized for its probiotic properties, on the composition of the intestinal microbiota in two model animals. UCC118 has anti-infective activity due to production of the bacteriocin Abp118, a broad-spectrum class IIb bacteriocin, which we hypothesized could impact the microbiota. Mice and pigs were administered wild-type (WT L. salivarius UCC118 cells, or a mutant lacking bacteriocin production. The microbiota composition was determined by pyrosequencing of 16S rRNA gene amplicons from faeces. The data show that L. salivarius UCC118 administration had no significant effect on proportions of major phyla comprising the mouse microbiota, whether the strain was producing bacteriocin or not. However, L. salivarius UCC118 WT administration led to a significant decrease in Spirochaetes levels, the third major phylum in the untreated pig microbiota. In both pigs and mice, L. salivarius UCC118 administration had an effect on Firmicutes genus members. This effect was not observed when the mutant strain was administered, and was thus associated with bacteriocin production. Surprisingly, in both models, L. salivarius UCC118 administration and production of Abp118 had an effect on gram-negative microorganisms, even though Abp118 is normally not active in vitro against this group of microorganisms. Thus L. salivarius UCC118 administration has a significant but subtle impact on mouse and pig microbiota, by a mechanism that seems at least partially

  5. Isolation and characterization of plantaricin ASM1: a new bacteriocin produced by Lactobacillus plantarum A-1.

    Science.gov (United States)

    Hata, Tomomi; Tanaka, Rie; Ohmomo, Sadahiro

    2010-01-31

    Bacteriocins produced by lactic acid bacteria showing stability even in neutral and weak alkaline pH were screened, and a new bacteriocin produced by Lactobacillus plantarum A-1, plantaricin ASM1 (PASM1) was purified and characterized. This bacteriocin which is heat-stable but digested by trypsin inhibits the growth of lactic acid bacterial species, such as Lactobacillus, Leuconostoc, and Enterococcus. PASM1 showed stability in a wide pH range compared to nisin A. The bacteriocin was purified using cation exchange, hydrophobic interaction, and reverse-phase high-performance liquid chromatography. The activity of the purified bacteriocin was obtained as one fraction. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis of the fraction showed a mass of 5045.7Da. Combining the data obtained from amino acid and DNA sequencing, the primary sequence of PASM1 was determined. The sequence of the corresponding gene revealed that the peptide is ribosomally synthesized as a 64 amino acid precursor containing a 21 amino acid N-terminal extension of the double-glycine type. The mature peptide consists of 43 amino acids, which could contain two intramolecular disulfide bonds in the structure. Three putative open reading frames were located upstream of the PLNA1 gene. These genes may encode the thioredoxin family proteins and a response regulator both of which have been suggested to regulate expression of the PASM1 gene and the processing of its leader peptide. PASM1 has no reported homologue bacteriocins. Stability in a wide pH range and heat indicates its potential for application in food preservation. Copyright 2009 Elsevier B.V. All rights reserved.

  6. Coculture-inducible bacteriocin biosynthesis of different probiotic strains by dairy starter culture Lactococcus lactis

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    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.

  7. Optimization of growth and bacteriocin production by Lactobacillus sakei subsp. sakei2a

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    Patrícia S. Malheiros

    2015-09-01

    Full Text Available Lactobacillus sakei subsp. sakei 2a is a bacteriocinogenic lactic acid bacterium isolated from Brazilian pork sausage, capable of inhibiting the growth of microbial pathogens, mainly Listeria monocytogenes. In order to optimize bacteriocin production for industrial applications, this study evaluated the effect of supplementation of MRS broth with glucose, Tween 20, Tween 80, sodium citrate, potassium chloride and cysteine, and effect of the initial pH and temperature of incubation of the medium on production of bacteriocins by L. sakei 2a. Adding glucose and Tween 20 to the medium, an initial pH of 5.0 or 5.5, and incubation temperatures of 25 °C or 30 °C resulted to the highest bacteriocin yields. Thus, a 24 factorial design with the four variables was performed, and statistical analysis showed that it was an adequate model (R2 = 0.8296. In the studied range, the four parameters significantly influenced bacteriocin production, with the maximum yield produced at an initial pH between 5.5 and 7.0, a temperature between 25 and 30 °C and supplementation of the MRS broth with glucose from 3.25 to 6.0 g L−1 and Tween 20 from 0.575 to 1.15% (v/v. Response Surface Methodology analysis indicated that the highest bacteriocin production (12800 AU mL−1 occurred in the MRS broth supplemented with 5.5 g L−1 glucose and 1.05% Tween 20 at an initial pH of 6.28 and an incubation temperature of 25 °C. The amount of bacteriocin produced in commercial MRS broths under the same conditions was only 5600AU mL−1.

  8. F-Type Bacteriocins of Listeria monocytogenes: a New Class of Phage Tail-Like Structures Reveals Broad Parallel Coevolution between Tailed Bacteriophages and High-Molecular-Weight Bacteriocins.

    Science.gov (United States)

    Lee, Grace; Chakraborty, Urmi; Gebhart, Dana; Govoni, Gregory R; Zhou, Z Hong; Scholl, Dean

    2016-10-15

    Listeria monocytogenes is a significant foodborne human pathogen that can cause severe disease in certain high-risk individuals. L. monocytogenes is known to produce high-molecular-weight, phage tail-like bacteriocins, or "monocins," upon induction of the SOS system. In this work, we purified and characterized monocins and found them to be a new class of F-type bacteriocins. The L. monocytogenes monocin genetic locus was cloned and expressed in Bacillus subtilis, producing specifically targeted bactericidal particles. The receptor binding protein, which determines target cell specificity, was identified and engineered to change the bactericidal spectrum. Unlike the F-type pyocins of Pseudomonas aeruginosa, which are related to lambda-like phage tails, monocins are more closely related to TP901-1-like phage tails, structures not previously known to function as bacteriocins. Monocins therefore represent a new class of phage tail-like bacteriocins. It appears that multiple classes of phage tails and their related bacteriocins have coevolved separately in parallel. Phage tail-like bacteriocins (PTLBs) are structures widespread among the members of the bacterial kingdom that are evolutionarily related to the DNA delivery organelles of phages (tails). We identified and characterized "monocins" of Listeria monocytogenes and showed that they are related to the tail structures of TP901-1-like phages, structures not previously known to function as bacteriocins. Our results show that multiple types of envelope-penetrating machines have coevolved in parallel to function either for DNA delivery (phages) or as membrane-disrupting bacteriocins. While it has commonly been assumed that these structures were coopted from phages, we cannot rule out the opposite possibility, that ancient phages coopted complex bacteriocins from the cell, which then underwent adaptations to become efficient at translocating DNA. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  9. The complete genome sequence of Lactobacillus plantarum LPL-1, a novel antibacterial probiotic producing class IIa bacteriocin.

    Science.gov (United States)

    Wang, Yao; Shang, Nan; Qin, Yuxuan; Zhang, Ying; Zhang, Jinlan; Li, Pinglan

    2018-01-20

    Bacteriocins are antibacterial proteins or peptides synthesized by ribosomes to inhibit or kill both closely related and non-related bacterium. Class IIa bacteriocins possess high activity against foodborne pathogen Listeria monocytogenes. A novel strain Lactobacillus plantarum LPL-1 was isolated from fermented fish and considered as a bacteriocin producing probiotic with great antibacterial activity against Listeria monocytogenes 54002. The complete genome of L. plantarum LPL-1 contains one circular chromosome and plasmid. According to the genome, biosynthetic genes of bacteriocin including precursor, immunity protein,accessory protein and transporter protein were identified; and biosynthetic mechanism of class IIa bacteriocin was also further analyzed. The antibacterial activity of purified bacteriocin against L.monocytogenes54002 was determined and the diameter of inhibition zone was about 16.6 mm by vernier caliper. This work provided the complete genome information of L. plantarum LPL-1 that could benefit for understanding the biosynthetic mechanism of class IIa bacteriocin as well as the potential application of L. plantarum LPL-1 in nutraceutical and pharmaceutical. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Characterization of a new bacteriocin from Lactobacillus plantarum LE5 and LE27 isolated from ensiled corn.

    Science.gov (United States)

    Amortegui, Jairo; Rodríguez-López, Alexander; Rodríguez, Deicy; Carrascal, Ana K; Alméciga-Díaz, Carlos J; Melendez, Adelina del P; Sánchez, Oscar F

    2014-04-01

    Bacteriocins are low molecular peptides with antimicrobial activity, which are of great interest as food bio-preservatives and for treating diseases caused by pathogenic bacteria. In this study, we present the characterization of bacteriocins produced by Lactobacillus plantarum LE5 and LE27 isolated from ensiled corn. Bacteriocins were purified through ammonium sulfate precipitation and double dialysis by using 12- and 1-kDa membranes. Bacteriocins showed activity against Listeria innocua, Listeria monocytogenes, and Enteroccocus faecalis. Molecular weight was estimated through Tricine-SDS-PAGE and overloading the gel onto Mueller-Hinton agar seeded with L. monocytogenes, showing an inhibition zone between 5 and 10 kDa. NanoLC-MS/MS analysis allowed the identification of UPF0291 protein (UniProtKB/Swiss-Prot Q88VI7), which is also presented in other lactic acid bacteria without assigned function. Ab initio modeling showed it has an α-helix-rich structure and a large positive-charged region. Bacteriocins were stable between 4 and 121 °C and pH 2 and 12, and the activity was inhibited by SDS and proteases. Mode of action assay suggests that the bacteriocin causes of target microorganism. Taken together, these results describe a possible new class IIa bacteriocin produced by L. plantarum, which has a wide stability to physicochemical conditions, and that could be used as an alternative for the control of foodborne diseases.

  11. ANTIMICROBIAL ACTIVITY OF BACTERIOCIN FROM INDIGENOUS Lactobacillus plantarum 2C12 AND ITS APPLICATION ON BEEF MEATBALL AS BIOPRESERVATIVE

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    T. Suryati

    2012-06-01

    Full Text Available One purpose of food preservation is to extend the shelf life of foods. Biological preservations can be conducted by adding antimicrobial substances, such as bacteriocin produced by lactic acid bacteria and has been characterized as biopreservatives. The aims of this research were to evaluate antimicrobial activity of bacteriocin produced by indigenous lactic acid bacteria Lactobacillus plantarum 2C12 isolated from local beef and to study the quality of beef meatball with 0.3% bacteriocin as biopreservative at different storage times (0, 3, and 6 days in cold temperature (4oC, compared to 0.3% nitrite and control (without preservative. The results showed that bacteriocin from L. plantarum 2C12 could inhibit pathogenic bacteria such as Escherichia coli, Staphylococcus aureus and Salmonella Typhimurium. Bacteriocin was effective as well as nitrite as biopreservatives of meatballs by inhibiting the growth of total microbes and E. coli. The addition of bacteriocin did not lead the physical and nutritional changes in the meatballs. The quality of meatball with bacteriocin treatment conformed with Indonesia National Standard of meatball.

  12. ANTIMICROBIAL ACTIVITY OF BACTERIOCIN FROM INDIGENOUS Lactobacillus plantarum 2C12 AND ITS APPLICATION ON BEEF MEATBALL AS BIOPRESERVATIVE

    Directory of Open Access Journals (Sweden)

    I.I. Arief

    2014-10-01

    Full Text Available One purpose of food preservation is to extend the shelf life of foods. Biological preservations canbe conducted by adding antimicrobial substances, such as bacteriocin produced by lactic acid bacteriaand has been characterized as biopreservatives. The aims of this research were to evaluate antimicrobialactivity of bacteriocin produced by indigenous lactic acid bacteria Lactobacillus plantarum 2C12isolated from local beef and to study the quality of beef meatball with 0.3% bacteriocin asbiopreservative at different storage times (0, 3, and 6 days in cold temperature (4oC, compared to 0.3%nitrite and control (without preservative. The results showed that bacteriocin from L. plantarum 2C12could inhibit pathogenic bacteria such as Escherichia coli, Staphylococcus aureus and SalmonellaTyphimurium. Bacteriocin was effective as well as nitrite as biopreservatives of meatballs by inhibitingthe growth of total microbes and E. coli. The addition of bacteriocin did not lead the physical andnutritional changes in the meatballs. The quality of meatball with bacteriocin treatment conformed withIndonesia National Standard of meatball.

  13. Bacteriocin formation by dominant aerobic sporeformers isolated from traditional maari

    DEFF Research Database (Denmark)

    Kaboré, Donatien; Thorsen, Line; Nielsen, Dennis Sandris

    2012-01-01

    that the antimicrobial substances produced were heat stable, in-sensitive to catalase, sensitive to protease and trypsin but resistant to the proteolytic action of papain and proteinase K and equally active at pH values ranging from 3 to 11. Bacteriocin secretion started in late exponential growth phase and maximum...

  14. Characterization of Enterococcus durans 152 bacteriocins and their inhibition of Listeria monocytogenes in ham.

    Science.gov (United States)

    Du, Lihui; Liu, Fang; Zhao, Ping; Zhao, Tong; Doyle, Michael P

    2017-12-01

    Listeria monocytogenes is a nonfastidious, widely occurring foodborne pathogen that is a major challenge to the food industry. Enterococcus durans 152, a confirmed L. monocytogenes-control microorganism, was isolated from floor drain samples from a food processing facility. In this study, the two bacteriocins produced by E. durans 152 were characterized and identified as Dur 152A (an enterocin L50A derivative with two amino acid substitutions of I→M) and enterocin L50B. The bacteriocins were then partially purified and evaluated for inhibitory activity to L. monocytogenes in deli ham. Results revealed that at 400 AU/ml, the bacteriocins prevented growth of listeria in deli ham for at least 10 weeks at 8 °C and at least 30 days at 15 °C. For comparison, 500 ppm Nisin controlled listeria growth for up to 6 weeks at 8 °C and up to 18 days at 15 °C. These findings reveal the potential for the bacteriocins of E. durans 152 to serve as anti-listerial agents in deli meat. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Diversity of Streptococcus thermophilus in bacteriocin production; inhibitory spectrum and occurrence of thermophilin genes.

    Science.gov (United States)

    Rossi, Franca; Marzotto, Marta; Cremonese, Silvia; Rizzotti, Lucia; Torriani, Sandra

    2013-08-01

    The bacteriocin-producing Streptococcus thermophilus strains that can dominate in natural dairy ecosystems, may also enhance safety in products obtained from natural cultures. In this study, we sought to identify bacteriocin production and bacteriocin genes in 75 strains of dairy and plant origin. The strains were tested for antimicrobial activity against pathogens or pathogen models, spoiling bacteria, and lactic acid bacteria associated with dairy products. All strains moderately inhibited Staphylococcus aureus P310, none inhibited Listeria innocua LMG 11387(T) or Clostridium tyrobutyricum LMG 1285(T). In addition, 14 were active against one or more indicators in addition to S. aureus P310. Inhibition of other starter bacteria was more common than the inhibition of unwanted microorganisms. The involvement of a proteinaceous compound was ascertained in all cases. Results suggested that the selection of bacteriocinogenic S. thermophilus strains for use in biopreservation must take into account the effects exerted on other lactic acid bacteria. PCR detection of thermophilin genes proved unreliable in predicting antimicrobial activity. For S. thermophilus PRI36 and PRI45, with relevant inhibitory features, the identity of the bacteriocin genes present in the thermophilin 9 cluster was defined, thus revealing novel variants for this genome region. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Coordinated Bacteriocin Expression and Competence in Streptococcus pneumoniae Contributes to Genetic Adaptation through Neighbor Predation.

    Directory of Open Access Journals (Sweden)

    Wei-Yun Wholey

    2016-02-01

    Full Text Available Streptococcus pneumoniae (pneumococcus has remained a persistent cause of invasive and mucosal disease in humans despite the widespread use of antibiotics and vaccines. The resilience of this organism is due to its capacity for adaptation through the uptake and incorporation of new genetic material from the surrounding microbial community. DNA uptake and recombination is controlled by a tightly regulated quorum sensing system that is triggered by the extracellular accumulation of competence stimulating peptide (CSP. In this study, we demonstrate that CSP can stimulate the production of a diverse array of blp bacteriocins. This cross stimulation occurs through increased production and secretion of the bacteriocin pheromone, BlpC, and requires a functional competence regulatory system. We show that a highly conserved motif in the promoter of the operon encoding BlpC and its transporter mediates the upregulation by CSP. The accumulation of BlpC following CSP stimulation results in augmented activation of the entire blp locus. Using biofilm-grown organisms as a model for competition and genetic exchange on the mucosal surface, we demonstrate that DNA exchange is enhanced by bacteriocin secretion suggesting that co-stimulation of bacteriocins with competence provides an adaptive advantage. The blp and com regulatory pathways are believed to have diverged and specialized in a remote ancestor of pneumococcus. Despite this, the two systems have maintained a regulatory connection that promotes competition and adaptation by targeting for lysis a wide array of potential competitors while simultaneously providing the means for incorporation of their DNA.

  17. Bacteriocins with a broader antimicrobial spectrum prevail in enterococcal symbionts isolated from the hoopoe's uropygial gland.

    Science.gov (United States)

    Ruiz-Rodríguez, Magdalena; Martínez-Bueno, Manuel; Martín-Vivaldi, Manuel; Valdivia, Eva; Soler, Juan J

    2013-09-01

    The use of compounds produced by symbiotic bacteria against pathogens in animals is one of the most exciting discoveries in ecological immunology. The study of those antibiotic metabolites will enable an understanding of the defensive strategies against pathogenic infections. Here, we explore the role of bacteriocins explaining the antimicrobial properties of symbiotic bacteria isolated from the uropygial gland of the hoopoe (Upupa epops). The antagonistic activity of 187 strains was assayed against eight indicator bacteria, and the presence of six bacteriocin genes was detected in the genomic DNA. The presence of bacteriocin genes correlated with the antimicrobial activity of isolates. The most frequently detected bacteriocin genes were those encoding for the MR10 and AS-48 enterocins, which confer the highest inhibition capacity. All the isolates belonged to the genus Enterococcus, with E. faecalis as the most abundant species, with the broadest antimicrobial spectrum and the highest antagonistic activity. The vast majority of E. faecalis strains carried the genes of MR10 and AS-48 in their genome. Therefore, we suggest that fitness-related benefits for hoopoes associated with harbouring the most bactericidal symbionts cause the highest frequency of strains carrying MR10 and AS-48 genes. The study of mechanisms associated with the acquisition and selection of bacterial symbionts by hoopoes is necessary, however, to reach further conclusions. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  18. Pentocin KCA1: a novel circular bacteriocin gene encoded in the ...

    African Journals Online (AJOL)

    We isolated and carried out comprehensive genome sequence analysis of the first Lactobacillus pentosus KCA1 of human origin encoding genes for the biosynthesis of antimicrobial bacteriocin peptide. Due to the growing number of antimicrobial resistance, the need for developing alternatives to traditional antibiotics is ...

  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. 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)....

  1. Properties of durancin GL, a new antilisterial bacteriocin produced by Enterococcus durans 41D

    Science.gov (United States)

    The properties of the antilisterial durancin GL were characterized. The bacteriocin was the product of Enterococcus durans 41D which was isolated from Hispanic-style cheese samples. The antibacterial activity of durancin GL was only evident against Gram-positive bacteria, including Listeria specie...

  2. Identification and characterization of two novel clostridial bacteriocins, circularin A and closticin 574

    NARCIS (Netherlands)

    Kemperman, R; Kuipers, A; Karsens, H; Nauta, A; Kuipers, O; Kok, J

    Two novel antibacterial peptides of clostridiall species were purified, N-terminally sequenced, and characterized. Moreover, their structural genes were identified. Closticin 574 is an 82-amino-acid bacteriocin produced by Clostridium tyrobutyricum ADRIAT 932. The supernatant of the producing strain

  3. Genetic features of circular bacteriocins produced by Gram-positive bacteria

    NARCIS (Netherlands)

    Maqueda, Mercedes; Sánchez-Hidalgo, Marina; Fernández, Matilde; Montalbán-López, Manuel; Valdivia, Eva; Martínez-Bueno, Manuel

    This review highlights the main genetic features of circular bacteriocins, which require the co-ordinated expression of several genetic determinants. In general terms, it has been demonstrated that the expression of such structural genes must be combined with the activity of proteins involved in

  4. Complementary and Overlapping Selectivity of the Two-Peptide Bacteriocins Plantaricin EF and JK

    NARCIS (Netherlands)

    Moll, Gert N.; Akker, Emile van den; Hauge, Håvard H.; Nissen-Meyer, Jon; Nes, Ingolf F.; Konings, Wil N.; Driessen, Arnold J.M.

    1999-01-01

    Plantaricin EF and JK are both two-peptide bacteriocins produced by Lactobacillus plantarum C11. The mechanism of plantaricin EF and JK action was studied on L. plantarum 965 cells. Both plantaricins form pores in the membranes of target cells and dissipate the transmembrane electrical potential

  5. Cysteine S-glycosylation, a new post-translational modification found in glycopeptide bacteriocins

    Czech Academy of Sciences Publication Activity Database

    Stepper, J.; Shastri, S.; Loo, T. S.; Preston, J. C.; Novák, Petr; Man, Petr; Moore, Ch. H.; Havlíček, Vladimír; Patchett, M. L.; Norris, G. E.

    2011-01-01

    Roč. 585, č. 4 (2011), s. 645-650 ISSN 0014-5793 Institutional research plan: CEZ:AV0Z50200510 Keywords : Post-translational modification * Glycosylation * Bacteriocin Subject RIV: CE - Biochemistry Impact factor: 3.538, year: 2011

  6. Pediocin PA-1, a wide-spectrum bacteriocin from lactic acid bacteria

    NARCIS (Netherlands)

    Rodriguez, JM; Martinez, MI; Kok, J

    2002-01-01

    Pediocin PA-1 is a broad-spectrum lactic acid bacteria bacteriocin that shows a particularly strong activity against Listeria monocytogenes, a foodborne pathogen of special concern among the food industries. This antimicrobial peptide is the most extensively studied class IIa (or pediocin family)

  7. Pentocin KCA1: a novel circular bacteriocin gene encoded in the ...

    African Journals Online (AJOL)

    ABSTRACT. Background: The use of bacteriocin and bacterial strains that produces the antimicrobial peptide has shown to possess potential applications in the conferment of health benefits on the host. We isolated and carried out comprehensive genome sequence analysis of the first. Lactobacillus pentosus KCA1 of ...

  8. A Natural Chimeric Pseudomonas Bacteriocin with Novel Pore-Forming Activity Parasitizes the Ferrichrome Transporter

    Directory of Open Access Journals (Sweden)

    Maarten G. K. Ghequire

    2017-02-01

    Full Text Available Modular bacteriocins represent a major group of secreted protein toxins with a narrow spectrum of activity, involved in interference competition between Gram-negative bacteria. These antibacterial proteins include a domain for binding to the target cell and a toxin module at the carboxy terminus. Self-inhibition of producers is provided by coexpression of linked immunity genes that transiently inhibit the toxin’s activity through formation of bacteriocin-immunity complexes or by insertion in the inner membrane, depending on the type of toxin module. We demonstrate strain-specific inhibitory activity for PmnH, a Pseudomonas bacteriocin with an unprecedented dual-toxin architecture, hosting both a colicin M domain, potentially interfering with peptidoglycan synthesis, and a novel colicin N-type domain, a pore-forming module distinct from the colicin Ia-type domain in Pseudomonas aeruginosa pyocin S5. A downstream-linked gene product confers PmnH immunity upon susceptible strains. This protein, ImnH, has a transmembrane topology similar to that of Pseudomonas colicin M-like and pore-forming immunity proteins, although homology with either of these is essentially absent. The enhanced killing activity of PmnH under iron-limited growth conditions reflects parasitism of the ferrichrome-type transporter for entry into target cells, a strategy shown here to be used as well by monodomain colicin M-like bacteriocins from pseudomonads. The integration of a second type of toxin module in a bacteriocin gene could offer a competitive advantage against bacteria displaying immunity against only one of both toxic activities.

  9. Variable characteristics of bacteriocin-producing Streptococcus salivarius strains isolated from Malaysian subjects.

    Directory of Open Access Journals (Sweden)

    Abdelahhad Barbour

    Full Text Available BACKGROUND: Salivaricins are bacteriocins produced by Streptococcus salivarius, some strains of which can have significant probiotic effects. S. salivarius strains were isolated from Malaysian subjects showing variable antimicrobial activity, metabolic profile, antibiotic susceptibility and lantibiotic production. METHODOLOGY/PRINCIPAL FINDINGS: In this study we report new S. salivarius strains isolated from Malaysian subjects with potential as probiotics. Safety assessment of these strains included their antibiotic susceptibility and metabolic profiles. Genome sequencing using Illumina's MiSeq system was performed for both strains NU10 and YU10 and demonstrating the absence of any known streptococcal virulence determinants indicating that these strains are safe for subsequent use as probiotics. Strain NU10 was found to harbour genes encoding salivaricins A and 9 while strain YU10 was shown to harbour genes encoding salivaricins A3, G32, streptin and slnA1 lantibiotic-like protein. Strain GT2 was shown to harbour genes encoding a large non-lantibiotic bacteriocin (salivaricin-MPS. A new medium for maximum biomass production buffered with 2-(N-morpholinoethanesulfonic acid (MES was developed and showed better biomass accumulation compared with other commercial media. Furthermore, we extracted and purified salivaricin 9 (by strain NU10 and salivaricin G32 (by strain YU10 from S. salivarius cells grown aerobically in this medium. In addition to bacteriocin production, S. salivarius strains produced levan-sucrase which was detected by a specific ESI-LC-MS/MS method which indicates additional health benefits from the developed strains. CONCLUSION: The current study established the bacteriocin, levan-sucrase production and basic safety features of S. salivarius strains isolated from healthy Malaysian subjects demonstrating their potential for use as probiotics. A new bacteriocin-production medium was developed with potential scale up application for

  10. Cloning, purification, and functional characterization of Carocin S2, a ribonuclease bacteriocin produced by Pectobacterium carotovorum.

    Science.gov (United States)

    Chan, Yung-Chieh; Wu, Jian-Li; Wu, Huang-Pin; Tzeng, Kuo-Ching; Chuang, Duen-Yau

    2011-05-12

    Most isolates of Pectobacterium carotovorum subsp. carotovorum (Pcc) produce bacteriocins. In this study, we have determined that Pcc strain F-rif-18 has a chromosomal gene encoding the low-molecular-weight bacteriocin, Carocin S2, and that this bacteriocin inhibits the growth of a closely related strain. Carocin S2 is inducible by ultraviolet radiation but not by mutagenic agents such as mitomycin C. A carocin S2-defective mutant, TF1-2, was obtained by Tn5 insertional mutagenesis using F-rif-18. A 5706-bp DNA fragment was detected by Southern blotting, selected from a genomic DNA library, and cloned to the vector, pMS2KI. Two adjacent complete open reading frames within pMS2KI were sequenced, characterized, and identified as caroS2K and caroS2I, which respectively encode the killing protein and immunity protein. Notably, carocin S2 could be expressed not only in the mutant TF1-2 but also in Escherichia coli DH5α after entry of the plasmid pMS2KI. Furthermore, the C-terminal domain of CaroS2K was homologous to the nuclease domains of colicin D and klebicin D. Moreover, SDS-PAGE analysis showed that the relative mass of CaroS2K was 85 kDa and that of CaroS2I was 10 kDa. This study shown that another nuclease type of bacteriocin was found in Pectobacterium carotovorum. This new type of bacteriocin, Carocin S2, has the ribonuclease activity of CaroS2K and the immunity protein activity of CaroS2I.

  11. Cloning, purification, and functional characterization of Carocin S2, a ribonuclease bacteriocin produced by Pectobacterium carotovorum

    Directory of Open Access Journals (Sweden)

    Tzeng Kuo-Ching

    2011-05-01

    Full Text Available Abstract Background Most isolates of Pectobacterium carotovorum subsp. carotovorum (Pcc produce bacteriocins. In this study, we have determined that Pcc strain F-rif-18 has a chromosomal gene encoding the low-molecular-weight bacteriocin, Carocin S2, and that this bacteriocin inhibits the growth of a closely related strain. Carocin S2 is inducible by ultraviolet radiation but not by mutagenic agents such as mitomycin C. Results A carocin S2-defective mutant, TF1-2, was obtained by Tn5 insertional mutagenesis using F-rif-18. A 5706-bp DNA fragment was detected by Southern blotting, selected from a genomic DNA library, and cloned to the vector, pMS2KI. Two adjacent complete open reading frames within pMS2KI were sequenced, characterized, and identified as caroS2K and caroS2I, which respectively encode the killing protein and immunity protein. Notably, carocin S2 could be expressed not only in the mutant TF1-2 but also in Escherichia coli DH5α after entry of the plasmid pMS2KI. Furthermore, the C-terminal domain of CaroS2K was homologous to the nuclease domains of colicin D and klebicin D. Moreover, SDS-PAGE analysis showed that the relative mass of CaroS2K was 85 kDa and that of CaroS2I was 10 kDa. Conclusion This study shown that another nuclease type of bacteriocin was found in Pectobacterium carotovorum. This new type of bacteriocin, Carocin S2, has the ribonuclease activity of CaroS2K and the immunity protein activity of CaroS2I.

  12. Role of acetate in production of an autoinducible Class IIa Bacteriocin in Carnobacterium piscicola A9b

    DEFF Research Database (Denmark)

    Nilsson, Lilian; Nielsen, Michael Krogsgaard; Ng, Yin

    2002-01-01

    Carnobacterium piscicola strain A9b isolated from cold smoked salmon inhibits growth of the food-borne pathogen Listeria monocytogenes partly due to the production of a proteinaceous compound (L. Nilsson, L. Gram, and H. H. Huss. J. Food Prot. 62:336-342, 1999). The purpose of the present study...... was to purify the compound and describe factors affecting its production, with particular emphasis on food-relevant factors. Amino acid sequencing showed that the compound is a class IIa bacteriocin with an N-terminal amino acid sequence identical to that of carnobacteriocin B2. The production....... The induction of bacteriocin production showed a dose-dependent relationship at acetate concentrations of up to 10 to 20 mM (depending on the growth medium) and at a concentration of 1.9 x 10(-8) M for the bacteriocin itself; a saturation level of bacteriocin specific activity was reached...

  13. Short communication: Bacteriocin KC24 produced by Lactococcus lactis KC24 from kimchi and its antilisterial effect in UHT milk.

    Science.gov (United States)

    Han, E J; Lee, N-K; Choi, S Y; Paik, H-D

    2013-01-01

    The severity of Listeria monocytogenes infections emphasizes the need for prevention or elimination of the pathogen from dairy products. Lactococcus lactis KC24, isolated from kimchi, exhibited an antimicrobial effect against food pathogens, including L. monocytogenes ATCC 15313. Lactococcus lactis KC24 was cultured in a 5-L jar fermenter at 35°C, and bacteriocin activity was maximal at 4 h of incubation and persisted for 20 h. Bacteriocin KC24 was inactivated by protease XIV, indicating that it has a proteinaceous nature. Bacteriocin activity was maintained at pH 3.0 to 9.0 and at temperatures of 50 to 121°C. The mode of inhibition against L. monocytogenes ATCC 15313 was shown to involve a bactericidal effect by treatment with 100 and 200 arbitrary units (AU)/mL of bacteriocin KC24. To test the activity of bacteriocin KC24 in a food product, bacteriocin KC24 and nisin (100 and 200 AU/mL) with 4 log cfu/mL of a mixed culture of L. monocytogenes (ATCC 15313, ScottA, H7962, and H7762) were applied to UHT milk. Compared with the control, treatment with bacteriocin KC24 completely inhibited the growth of L. monocytogenes and resulted in no detectable L. monocytogenes after 14 d at 4°C, whereas nisin moderately inhibited L. monocytogenes, resulting in a final concentration after 14 d at 4°C higher than the initial inoculum. Bacteriocin KC24 may prove useful in improving the safety of dairy products. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  14. EFFECT OF CULTURE MEDIUM ON BACTERIOCIN PRODUCTION BY LACTOBACILLUS RHAMNOSUS HN001 AND LACTOBACILLUS REUTERI ATCC 53608

    Directory of Open Access Journals (Sweden)

    Aguilar-Uscanga B. R.

    2013-06-01

    Full Text Available The aim of this study was to evaluate the effect of media on bacteriocin production by Lactobacillus rhamnosus HN001 and Lactobacillus reuteri ATCC 53608 using three different media: YPM, YPF and MRS supplemented with glucose and K2HPO4. The optimum temperature was 37°C and initial pH 6.5. Bacteriocin-like substances produced by tested bacteria in MRS medium supplemented with glucose and K2HPO4 exhibited a broad antimicrobial spectrum determined by well diffusion assay against indicator bacteria Listeria monocytogenes, Lactobacillus sakei, Enterococcus faecium, Lactobacillus delbrueckii, Lactobacillus acidophilus, but no antimicrobial spectrum against E. coli O157:H7, Salmonella typhimurium, Staphylococcus aureus, Bacillus cereus was detected. Bacteriocin was sensitive to protease IV, trypsin, pepsin and -amylases, but resistant to lipase. It was also resistant to detergents such as Tween 80, Triton-X and SDS. This bacteriocin was thermo-stable (resistant at 60°C, 90°C and 100°C for 30 min. Tested bacteria showed the best antimicrobial (bacteriocin-like activity after growth in MRS medium. Bacteriocin substances produced by tested bacteria showed promising thermo-stable technological properties.

  15. Effect of Exogenous Factors on Bacteriocin Production from Lactobacillus paracasei J23 by Using a Resting Cell System

    Directory of Open Access Journals (Sweden)

    Huaxi Yi

    2013-12-01

    Full Text Available A resting cell system was developed for bacteriocin Lac-B23 production from Lactobacillus paracasei J23. The resting cell medium contained (g/L: Glucose 20, Sodium acetate 5.0, MnSO4 0.25 MgSO4 0.5, Ammoniumhydrogencitrate 1.0, KH2PO4 1.0. The resting cell incubation time and temperature were 20 h and 37 °C and the effects of exogenous factors, including amino acids, glycerol, pyruvic acid, and α-ketoglutaric acid were investigated. Cys and Gly could stimulate the production of bacteriocin, while no stimulus effect was observed for Glu, Tyr and Ala. Glycerol and pyruvic acid increased bacteriocin production and the optimum concentrations were 1% and 30 g/L, respectively. Bacteriocin could act as an inducer of its own biosynthesis. These findings are of importance for the further study of bacteriocin biosynthesis regulation and for the improvement of bacteriocin production yields.

  16. Inhibitory effect of bacteriocin-producing lactic acid bacteria against histamine-forming bacteria isolated from Myeolchi-jeot

    Directory of Open Access Journals (Sweden)

    Eun-Seo Lim

    2016-12-01

    Full Text Available Abstract The objectives of this study were to identify the histamine-forming bacteria and bacteriocin- producing lactic acid bacteria (LAB isolated from Myeolchi-jeot according to sequence analysis of the 16S rRNA gene, to evaluate the inhibitory effects of the bacteriocin on the growth and histamine accumulation of histamine-forming bacteria, and to assess the physico-chemical properties of the bacteriocin. Based on 16S rRNA gene sequences, histamine-forming bacteria were identified as Bacillus licheniformis MCH01, Serratia marcescens MCH02, Staphylococcus xylosus MCH03, Aeromonas hydrophila MCH04, and Morganella morganii MCH05. The five LAB strains identified as Pediococcus acidilactici MCL11, Leuconostoc mesenteroides MCL12, Enterococcus faecium MCL13, Lactobacillus sakei MCL14, and Lactobacillus acidophilus MCL15 were found to produce an antibacterial compound with inhibitory activity against the tested histamine-producing bacteria. The inhibitory activity of these bacteriocins obtained from the five LAB remained stable after incubation at pH 4.0–8.0 and heating for 10 min at 80 °C; however, the bacteriocin activity was destroyed after treatment with papain, pepsin, proteinase K, α-chymotrypsin, or trypsin. Meanwhile, these bacteriocins produced by the tested LAB strains also exhibited histamine-degradation ability. Therefore, these antimicrobial substances may play a role in inhibiting histamine formation in the fermented fish products and preventing seafood-related food-borne disease caused by bacterially generated histamine.

  17. Characterization of a heat stable anti-listerial bacteriocin produced by vancomycin sensitive Enterococcus faecium isolated from idli batter.

    Science.gov (United States)

    Vijayendra, S V N; Rajashree, K; Halami, Prakash M

    2010-06-01

    Lactic acid bacteria (LAB) are known to produce various types of bacteriocins, ribosomally synthesized polypeptides, which have antibacterial spectrum against many food borne pathogens. Listeria monocytogenes, a pathogenic bacterium, is of particular concern to the food industry because of its ability to grow even at refrigeration temperatures and its tolerance to preservative agents. Some of the bacteriocins of LAB are known to have anti-listerial property. In the present study, the bacteriocin produced by vancomycin sensitive Enterococcus faecium El and J4 isolated from idli batter samples was characterized. The isolates were found to tolerate high temperatures of 60°C for 15 and 30 min and 70°C for 15 min. The bacteriocin was found to be heat stable and had anti-listerial activity. The bacteriocin did not lost anti-listerial activity when treated at 100°C for 30 min or at 121°C for 15 min. The bacteriocin lost its antimicrobial activity after treating with trypsin, protinase-K, protease and peptidase.

  18. Screening and characterization of bacteriocins produced by some Strains of Lactobacillus spp isolated from Iranian Dairy products

    Directory of Open Access Journals (Sweden)

    S Mirdamadi

    2011-11-01

    Full Text Available In this study, the inhibitory effects of bacteriocins of lactobacilli which were isolated from Iranian traditional dairy products was determined against known gram positive, gram negative and yeast by well diffusion technique. Among 8 isolates with higher capability of bacteriocin production, 2 isolates were selected for further investigations. The bacteriocins were purified by iso-propanol and ammonium sulfate precipitation following by dialysis and chromatography technique. The molecular weight of bacteriocins was determined as 45 to 66/2 KDa. by SDS-page electrophoresis. According to the results, the produced bacteriocins had more inhibition effect on Micrococcus luteus PTCC1169, Staphylococcus epidermidis PTCC1435 as well as Bacillus cereus PTCC1247 and with lesser degree of extent on Listeria monocytogenes PTCC 1301. Results also revealed that, Micrococcus luteus  was the most sensitive bacterium among indicator bacteria, while Candid albicans PTCC 5027 identified as the most resistance organism. This research showed that, bacteriocins produced by lactobacilli isolated from traditional dairy products have high potency to be used against microbial pathogens and could be applied as bio-preservative in food products.

  19. Inhibitory activity of bacteriocin produced from Lactobacillus SCG 1223 toward L. monocytogenes, S. thypimurium and E. coli

    Science.gov (United States)

    Marwati, T.; Cahyaningrum, N.; Widodo, S.; Januarsyah, T.; Purwoko

    2018-01-01

    Bacteriocin is a protein compound which has bactericidal ability against pathogen bacteria. This research aims to study the inhibitory activity of bacteriocin produced from Lactobacillus SCG 1223 against Listeria monocytogenes, Salmonella thypimuruim and Escherchia coli. The bacteriocin produce from Lactobacillus SCG 1223 in the MRS broth media The experimental design used was Completely Randomized Design. The variations used in this design were percentage of inoculum (5%, 10%), medium pH (4, 6), incubation temperature (27°C, 40°C), and incubation time (4, 10, 14 hours). Result showed that bacteriocin from Lactobacillus SCG 1223 had wide spectrum toward L. monocytogenes, S. thypimuruim and E. coli. The highest bacteriocin activity toward L. monocytogenes produced by Lactobacillus SCG 1223 with 10% inoculum in media with initial pH 6, incubation temperature 27°C for 14 hour, toward S. thypimurium produced by Lactobacillus SCG 1223 with in media with initial pH 6, incubation temperature 40°C for 14 hour, and toward E. coli was 1085.81 AU/ml, produced by Lactobacillus SCG 1223 in MRS broth with initial pH 4, incubation temperature 40°C for 14 hour. This study is expected to find a new food preservative that can inhibit the growth of pathogenic bacteria and extend the shelf life of food. From the economic prospective of view, bacteriocin is very promising natural alternative biopreservatives.

  20. Diversity and distribution of nuclease bacteriocins in bacterial genomes revealed using Hidden Markov Models.

    Directory of Open Access Journals (Sweden)

    Connor Sharp

    2017-07-01

    Full Text Available Bacteria exploit an arsenal of antimicrobial peptides and proteins to compete with each other. Three main competition systems have been described: type six secretion systems (T6SS; contact dependent inhibition (CDI; and bacteriocins. Unlike T6SS and CDI systems, bacteriocins do not require contact between bacteria but are diffusible toxins released into the environment. Identified almost a century ago, our understanding of bacteriocin distribution and prevalence in bacterial populations remains poor. In the case of protein bacteriocins, this is because of high levels of sequence diversity and difficulties in distinguishing their killing domains from those of other competition systems. Here, we develop a robust bioinformatics pipeline exploiting Hidden Markov Models for the identification of nuclease bacteriocins (NBs in bacteria of which, to-date, only a handful are known. NBs are large (>60 kDa toxins that target nucleic acids (DNA, tRNA or rRNA in the cytoplasm of susceptible bacteria, usually closely related to the producing organism. We identified >3000 NB genes located on plasmids or on the chromosome from 53 bacterial species distributed across different ecological niches, including human, animals, plants, and the environment. A newly identified NB predicted to be specific for Pseudomonas aeruginosa (pyocin Sn was produced and shown to kill P. aeruginosa thereby validating our pipeline. Intriguingly, while the genes encoding the machinery needed for NB translocation across the cell envelope are widespread in Gram-negative bacteria, NBs are found exclusively in γ-proteobacteria. Similarity network analysis demonstrated that NBs fall into eight groups each with a distinct arrangement of protein domains involved in import. The only structural feature conserved across all groups was a sequence motif critical for cell-killing that is generally not found in bacteriocins targeting the periplasm, implying a specific role in translocating the

  1. 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.

  2. Antibacterial activity of bacteriocin-like substance P34 on Listeria monocytogenes in chicken sausage

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    Voltaire Sant'Anna

    2013-12-01

    Full Text Available The antimicrobial activity of the bacteriocin-like substance (BLS P34 against Listeria monocytogenes was investigated in chicken sausage. The BLS was applied to chicken sausages (256 AU g-1 previously inoculated with a suspension of 10² cfu g-1 of L. monocytogenes. BLS P34 inhibited the indicator microorganism in situ in all incubation times for up to 10 days at 5 °C. The effectiveness of BLS P34 was increased when it was added in combination with nisin. The bacteriocin was also tested in natural eatable natural bovine wrapping (salty semi-dried tripe against the same indicator microorganism, also showing inhibitory capability in vitro. BLS P34 showed potential to control L. monocytogenes in refrigerated meat products.

  3. Some growth parameters and antimicrobial activity of a bacteriocin-producing strain Pediococcus acidilactici 13.

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    Altuntas, Evrim Gunes; Cosansu, Serap; Ayhan, Kamuran

    2010-06-30

    Some growth parameters and bacteriocin production by the strain Pediococcus acidilactici 13, were screened in this study. The inhibitor substance produced by this strain showed strong antimicrobial activity at 204,800 AU/mL (Activity Units/mL) against the gram positive food borne pathogen, Listeria monocytogenes, when the incubation temperature was 37 degrees C and the initial pH of the medium, TGE (Trypton Glucose Yeast Extract), was 6.0. The bacteriocin-producing strain had considerable resistance NaCl, since the strain maintained to growth up to 10% NaCl concentrations at TGE broth and was able to grow in a wide temperature range (25-50 degrees C). The strain was identified as P. acidilactici with API 50 CHL, as well as with 16S rRNA gene sequencing. 2010. Published by Elsevier B.V. All rights reserved.

  4. Growth inhibition of foodborne pathogens by kimchi prepared with bacteriocin-producing starter culture.

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    Chang, Ji Yoon; Chang, Hae Choon

    2011-01-01

    Kimchi (starter kimchi) was prepared with Leuconostoc citreum GJ7, a bacteriocin producer, with the objective of preventing growth and/or survival of foodborne pathogens such as Escherichia coli O157:H7, Salmonella Typhi, and Staphylococcus aureus. Numbers of the pathogens inoculated to 5.41 to 5.63 log CFU/mL into the filtrate of freshly made starter kimchi remained stable for the first 12 h of incubation at 10 °C. Reductions of 2.69, 2.88, and 3.42 log CFU/mL were observed 48 h after inoculation with E. coli O157:H7, S. Typhi, and S. aureus, respectively. Use of the bacteriocin-producing starter culture for kimchi fermentation significantly reduced the numbers of pathogens in the filtrate. Reductions of 3.85, 4.45, and 5.19 log CFU/mL were observed 48 h after inoculation for E. coli O157:H7, S. Typhi, and S. aureus, respectively. Presumably, the antimicrobial activity came from the ingredients of kimchi such as sulfur-containing compounds, low pH (approximately pH 4.5) produced by the conversion of sugars into organic acids and the bacteriocins potentially produced by lactic acid bacteria (LAB), such as kimchicin GJ7. Together, these data suggest that addition of a starter culture capable of producing bacteriocins could serve as a strategy to protect the fermented product from delivering pathogens upon consumption and that the kimchi filtrate itself may be used as a food preservative. Practical Application: The adaptation of the starter fermentation into kimchi induced a faster die off of the pathogens as compared to natural fermentation. The in situ bateriocin-production by Leuc. citreum GJ7 in kimchi would act with antimicrobial kimchi ingredients in a synergistic manner to protect the fermented product from delivering pathogens upon consumption.

  5. Production by Streptococcus sanguis of Bacteriocin-like Inhibitory Substances (BLIS) with Activity Against Streptococcus rattus

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    Skilton, C. J.; Tagg, J. R.

    2011-01-01

    A collection of 340 Streptoccus sanguis strains from 19 plaque specimens was isolated from cultures on tryptone, yeast extract, cystine (TYC) agar supplemented with sucrose (20 per cent) plus bacitracin (0.05 units/ml). By application of a deferred antagonism test procedure it was shown that 183 (53.8 per cent) of these relatively sucrose- and bacitracinresistant S. sanguis strains produced bacteriocin-like inhibitory substances (BLIS) having activity against strains of S. rattus, but apparcn...

  6. Antibacterial activity and optimisation of bacteriocin producing lactic acid bacteria isolated from beef (red meat) samples

    International Nuclear Information System (INIS)

    Ali, N.M.; Mazhar, B.; Khadija, I.; Kalim, B.

    2016-01-01

    Bacteriocin producing bacteria are commonly found in meat products to enhance their shelf-life. In the present study, bacterial species were isolated from meat samples (beef) from different localities of Lahore, Pakistan. MRS agar medium was used to isolate lactic acid bacteria (LAB) through spread and streak methods (incubated for 72 h at 37 degree C). Identification of bacteriocinogenic LAB strains was done by using staining techniques, morphology based characteristics and biochemical tests. These strains were BSH 1b, BSH 3a, BIP 4a, BIP 3a, BIP 1b and BRR 3a. Antibacterial activity of LAB was performed against food borne pathogens viz., Escherichia coli and Staphylococcus aureus through paper disc diffusion method. Three bacterial strains showed maximum inhibition and characterised by ribotyping viz., BIP 4a was identified as Lactobacillus curvatures, BIP 3a was Staphylococcus warneri and BIP 1b was Lactobacillus graminis . Optimum pH 5-6.5 and 30-37 degree C temperature for isolated bacterial strains was recorded. Protein concentration measured was 0.07 mg/mL for BSH 1b, 0.065 mg/mL for BSH 3a, 0.057 mg/mL for BIP 4a, 0.062 mg/mL for BIP 1b, 0.065 mg/mL for BIP 3a and for BRR 3a 0.078 mg/mL, respectively. Bacteriocin of all isolates except BIP 3a was found to be sensitive towards pepsin and resistant towards Rnase. Bacteriocin production was stable at between pH 5.0 and 6.0 and resistant temperature was 40 degree C. It was concluded that lactic acid bacteria (LAB) from meat can be helpful as antibacterial agents against food-borne bacterial pathogens because of thermostable producing bacteriocin. (author)

  7. Isolation and Characterization of a Broad Spectrum Bacteriocin from Bacillus amyloliquefaciens RX7

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    Kong Boon Lim

    2016-01-01

    Full Text Available We isolated a Bacillus strain, RX7, with inhibitory activity against Listeria monocytogenes from soil and identified it as Bacillus amyloliquefaciens based on 16S rRNA gene sequencing. The inhibitory activity was stable over a wide range of pH and was fully retained after 30 min at 80°C, after which it decreased gradually at higher temperatures. The activity was sensitive to the proteolytic action of α-chymotrypsin, proteinase-K, and trypsin, indicating its proteinaceous nature. This bacteriocin was active against a broad spectrum of bacteria and the fungus Candida albicans. Direct detection of antimicrobial activity on a sodium dodecyl sulfate-polyacrylamide gel suggested an apparent molecular mass of approximately 5 kDa. Ammonium sulfate precipitation and anion-exchange and gel permeation chromatography integrated with reverse phase-high-performance liquid chromatography were used for bacteriocin purification. Automated N-terminal Edman degradation of the purified RX7 bacteriocin recognized the first 15 amino acids as NH2-X-Ala-Trp-Tyr-Asp-Ile-Arg-Lys-Leu-Gly-Asn-Lys-Gly-Ala, where the letter X in the sequence indicates an unknown or nonstandard amino acid. Based on BLAST similarity search and multiple alignment analysis, the obtained partial sequence showed high homology with the two-peptide lantibiotic haloduracin (HalA1 from Bacillus halodurans, although at least two amino acids differed between the sequences. A time-kill study demonstrated a bactericidal mode of action of RX7 bacteriocin.

  8. Analysis of Lactobacillus Products for Phages and Bacteriocins That Inhibit Vaginal Lactobacilli

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    Lin Tao

    1997-01-01

    Full Text Available Objective: Bacterial vaginosis is associated with an unexplained loss of vaginal lactobacilli. Previously, we have identified certain vaginal lactobacilli-released phages that can inhibit in vitro other vaginal lactobacilli. However, there is no apparent route for phages to be transmitted among women. The purpose of this study was to identify whether certain Lactobacillus products commonly used by women release phages or bacteriocins that can inhibit vaginal lactobacilli.

  9. Quorum Sensing Regulation of Competence and Bacteriocins in Streptococcus pneumoniae and mutans

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    Shanker, Erin; Federle, Michael J.

    2017-01-01

    The human pathogens Streptococcus pneumoniae and Streptococcus mutans have both evolved complex quorum sensing (QS) systems that regulate the production of bacteriocins and the entry into the competent state, a requirement for natural transformation. Natural transformation provides bacteria with a mechanism to repair damaged genes or as a source of new advantageous traits. In S. pneumoniae, the competence pathway is controlled by the two-component signal transduction pathway ComCDE, which directly regulates SigX, the alternative sigma factor required for the initiation into competence. Over the past two decades, effectors of cellular killing (i.e., fratricides) have been recognized as important targets of the pneumococcal competence QS pathway. Recently, direct interactions between the ComCDE and the paralogous BlpRH pathway, regulating bacteriocin production, were identified, further strengthening the interconnections between these two QS systems. Interestingly, a similar theme is being revealed in S. mutans, the primary etiological agent of dental caries. This review compares the relationship between the bacteriocin and the competence QS pathways in both S. pneumoniae and S. mutans, and hopes to provide clues to regulatory pathways across the genus Streptococcus as a potential tool to efficiently investigate putative competence pathways in nontransformable streptococci. PMID:28067778

  10. Partial Characterisation of Bacteriocins Produced by Bacillus cereus Isolates from Milk and Milk Products

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    Bojana Bogović Matijašić

    2003-01-01

    Full Text Available Thirty one (19.2 % out of 161 Bacillus cereus isolates from raw milk and milk products were found to produce proteinaceous substances which inhibit the growth of other B. cereus isolates. The detection of antibacterial activity depended on medium and method used. Bactericidal activity was detected in 23 (14 % or 19 (12 % of the tested strains on the triptic soya agar and brain-heart infusion with glucose, respectively, while 11 (7 % of the strains produced bactericidal substances on both media. Nineteen percent of isolates from raw milk and 20 % of isolates from milk products were found to produce bacteriocins. Four B. cereus isolates inhibited the growth of individual test strains belonging to B. licheniformis, B. subtilis, Enterococcus faecalis, Escherichia coli, Staphylococcus aureus, Lactobacillus helveticus and L. casei species. The bacteriocins of four B. cereus isolates were studied in more detail. The production and activity of these substances were detected in stationary- phase of bacterial culture. Two of them were stable after heating at 60 °C, while only one was stable after heating at 75 °C for 15 minutes. All of them were active over a range of pH=3–10. The apparent molecular weights of four bacteriocins detected by SDS-PAGE electrophoresis were in the range of 1 to 8 kDa.

  11. Simultaneous Production of Biosurfactants and Bacteriocins by Probiotic Lactobacillus casei MRTL3

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    Sharma, Deepansh; Singh Saharan, Baljeet

    2014-01-01

    Lactic acid bacteria (LAB) are ubiquitous and well-known commensal bacteria in the human and animal microflora. LAB are extensively studied and used in a variety of industrial and food fermentations. They are widely used for humans and animals as adjuvants, probiotic formulation, and dietary supplements and in other food fermentation applications. In the present investigation, LAB were isolated from raw milk samples collected from local dairy farms of Haryana, India. Further, the isolates were screened for simultaneous production of biosurfactants and bacteriocins. Biosurfactant produced was found to be a mixture of lipid and sugar similar to glycolipids. The bacteriocin obtained was found to be heat stable (5 min at 100°C). Further, DNA of the strain was extracted and amplified by the 16S rRNA sequencing using universal primers. The isolate Lactobacillus casei MRTL3 was found to be a potent biosurfactant and bacteriocin producer. It seems to have huge potential for food industry as a biopreservative and/or food ingredient. PMID:24669225

  12. Purification and characterization of Plantaricin ZJ5, a new bacteriocin produced by Lactobacillus plantarum ZJ5.

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    Da-Feng Song

    Full Text Available The aim of this study is to investigate the antimicrobial potential of Lactobacillus plantarum ZJ5, a strain isolated from fermented mustard with a broad range of inhibitory activity against both Gram-positive and Gram-negative bacteria. Here we present the peptide plantaricin ZJ5 (PZJ5, which is an extreme pH and heat-stable. However, it can be digested by pepsin and proteinase K. This peptide has strong activity against Staphylococcus aureus. PZJ5 has been purified using a multi-step process, including ammonium sulfate precipitation, cation-exchange chromatography, hydrophobic interactions and reverse-phase chromatography. The molecular mass of the peptide was found to be 2572.9 Da using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS. The primary structure of this peptide was determined using amino acid sequencing and DNA sequencing, and these analyses revealed that the DNA sequence translated as a 44-residue precursor containing a 22-amino-acid N-terminal extension that was of the double-glycine type. The bacteriocin sequence exhibited no homology with known bacteriocins when compared with those available in the database, indicating that it was a new class IId bacteriocin. PZJ5 from a food-borne strain may be useful as a promising probiotic candidate.

  13. Simultaneous Production of Biosurfactants and Bacteriocins by Probiotic Lactobacillus casei MRTL3

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    Deepansh Sharma

    2014-01-01

    Full Text Available Lactic acid bacteria (LAB are ubiquitous and well-known commensal bacteria in the human and animal microflora. LAB are extensively studied and used in a variety of industrial and food fermentations. They are widely used for humans and animals as adjuvants, probiotic formulation, and dietary supplements and in other food fermentation applications. In the present investigation, LAB were isolated from raw milk samples collected from local dairy farms of Haryana, India. Further, the isolates were screened for simultaneous production of biosurfactants and bacteriocins. Biosurfactant produced was found to be a mixture of lipid and sugar similar to glycolipids. The bacteriocin obtained was found to be heat stable (5 min at 100°C. Further, DNA of the strain was extracted and amplified by the 16S rRNA sequencing using universal primers. The isolate Lactobacillus casei MRTL3 was found to be a potent biosurfactant and bacteriocin producer. It seems to have huge potential for food industry as a biopreservative and/or food ingredient.

  14. Amylocyclicin, a Novel Circular Bacteriocin Produced by Bacillus amyloliquefaciens FZB42

    Science.gov (United States)

    Scholz, Romy; Vater, Joachim; Budiharjo, Anto; Wang, Zhiyuan; He, Yueqiu; Dietel, Kristin; Schwecke, Torsten; Herfort, Stefanie; Lasch, Peter

    2014-01-01

    Bacillus amyloliquefaciens FZB42 is a Gram-positive plant growth-promoting bacterium with an impressive capacity to synthesize nonribosomal secondary metabolites with antimicrobial activity. Here we report on a novel circular bacteriocin which is ribosomally synthesized by FZB42. The compound displayed high antibacterial activity against closely related Gram-positive bacteria. Transposon mutagenesis and subsequent site-specific mutagenesis combined with matrix-assisted laser desorption ionization–time of flight mass spectroscopy revealed that a cluster of six genes covering 4,490 bp was responsible for the production, modification, and export of and immunity to an antibacterial compound, here designated amylocyclicin, with a molecular mass of 6,381 Da. Peptide sequencing of the fragments obtained after tryptic digestion of the purified peptide revealed posttranslational cleavage of an N-terminal extension and head-to-tail circularization of the novel bacteriocin. Homology to other putative circular bacteriocins in related bacteria let us assume that this type of peptide is widespread among the Bacillus/Paenibacillus taxon. PMID:24610713

  15. Partial Characterization of Bacteriocins Produced by Two New Enterococcus faecium Isolated from Human Intestine.

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    Turgis, Mélanie; Vu, Khanh Dang; Lacroix, Monique

    2013-06-01

    This study aimed at characterizing two novel bacteriocin-producing enterococcal strains isolated from human intestine. A total of 200 lactic acid bacteria were isolated from a woman stool sample. Two of them were selected for characterization due to their high antimicrobial activity against five strains of Listeria monocytogenes. The selected bacteria were identified as two different strains of Enterococcus faecium and designated MT 104 and MT 162. The bacteriocins produced by MT 104 and MT 162 were stable at different pH ranging from 2 to 11 and were active after different treatments such as heat, enzymes, detergents, and γ-irradiation. The two isolated strains exhibited some probiotic properties such as survival in simulated gastric fluid and intestinal fluid, lack of expression of bile salt hydrolase or hemolytic activity, adhesion to Caco-2 cells efficiently, and sensitivity to clinical antimicrobial agents. Thus, the two isolated strains of E. faecium could become new probiotic bacteria and their bacteriocins could be used for controlling L. monocytogenes in combination with irradiation for food preservation.

  16. A Microplate Growth Inhibition Assay for Screening Bacteriocins against Listeria monocytogenes to Differentiate Their Mode-of-Action

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    Paul Priyesh Vijayakumar

    2015-06-01

    Full Text Available Lactic acid bacteria (LAB have historically been used in food fermentations to preserve foods and are generally-recognized-as-safe (GRAS by the FDA for use as food ingredients. In addition to lactic acid; some strains also produce bacteriocins that have been proposed for use as food preservatives. In this study we examined the inhibition of Listeria monocytogenes 39-2 by neutralized and non-neutralized bacteriocin preparations (Bac+ preps produced by Lactobacillus curvatus FS47; Lb. curvatus Beef3; Pediococcus acidilactici Bac3; Lactococcus lactis FLS1; Enterococcus faecium FS56-1; and Enterococcus thailandicus FS92. Activity differences between non-neutralized and neutralized Bac+ preps in agar spot assays could not readily be attributed to acid because a bacteriocin-negative control strain was not inhibitory to Listeria in these assays. When neutralized and non-neutralized Bac+ preps were used in microplate growth inhibition assays against L. monocytogenes 39-2 we observed some differences attributed to acid inhibition. A microplate growth inhibition assay was used to compare inhibitory reactions of wild-type and bacteriocin-resistant variants of L. monocytogenes to differentiate bacteriocins with different modes-of-action (MOA whereby curvaticins FS47 and Beef3, and pediocin Bac3 were categorized to be in MOA1; enterocins FS92 and FS56-1 in MOA2; and lacticin FLS1 in MOA3. The microplate bacteriocin MOA assay establishes a platform to evaluate the best combination of bacteriocin preparations for use in food applications as biopreservatives against L. monocytogenes.

  17. Determination of bacteriocin activity with bioassays carried out on solid and liquid substrates: assessing the factor "indicator microorganism"

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    Ambrosiadis Ioannis

    2006-10-01

    Full Text Available Abstract Background Successful application of growth inhibition techniques for quantitative determination of bacteriocins relies on the sensitivity of the applied indicator microorganism to the bacteriocin to which is exposed. However, information on indicator microorganisms' performance and comparisons in bacteriocin determination with bioassays is almost non-existing in the literature. The aim of the present work was to evaluate the parameter "indicator microorganism" in bioassays carried out on solid -agar diffusion assay- and liquid -turbidometric assay- substrates, applied in the quantification of the most studied bacteriocin nisin. Results The performance of characterized microorganisms of known sources, belonging to the genera of Lactobacillus, Pediococcus, Micrococcus and Leuconostoc, has been assessed in this work in the assays of plate agar diffusion and turbidometry. Dose responses and sensitivities were examined and compared over a range of assay variables in standard bacteriocin solutions, fermentation broth filtrates and processed food samples. Measurements on inhibition zones produced on agar plates were made by means of digital image analysis. The data produced were analyzed statistically using the ANOVA technique and pairwise comparisons tests. Sensitivity limits and linearity of responses to bacteriocin varied significantly among different test-microorganisms in both applied methods, the lower sensitivity limits depending on both the test-microorganism and the applied method. In both methods, however, only two of the nine tested microorganisms (Lactobacillus curvatus ATCC 51436 and Pediococcus acidilactici ATCC 25740 were sensitive to very low concentrations of the bacteriocin and produced a linear-type of response in all kinds of samples used in this work. In all cases, very low bacteriocin concentrations, e.g. 1 IU/ml nisin, were more accurately determined in the turbidometric assay. Conclusion The present work shows that in

  18. Effect of Growth Medium on Bacteriocin Production by Lactobacillus plantarum ST194BZ, a Strain Isolated from Boza

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    Svetoslav Dimitrov Todorov

    2005-01-01

    Full Text Available The cell-free supernatant containing bacteriocin ST194BZ, produced by Lactobacillus plantarum ST194BZ, inhibits the growth of Lactobacillus casei, Lactobacillus sakei, Lactobacillus delbrueckii subsp. bulgaricus, Enterococcus faecalis, Escherichia coli, Enterobacter cloacae and Pseudomonas aeruginosa. Strain ST194BZ produces two bacteriocins, viz. ST194BZ(a of 3.3 kDa and ST194BZ(b of 14.0 kDa, based on tricine-SDS-PAGE. Reduction in bacteriocin activity was observed after treatment with proteinase K, trypsin and pronase, but not with catalase and a-amylase. A maximum total bacteriocin activity of 12 800 AU/mL was recorded after 14 h in MRS broth. In MRS broth adjusted to pH=5.5, 6.0 or 6.5, an equal level of bacteriocin production of 12 800 AU/mL was recorded. Optimal production (12 800 AU/ mL was recorded in the presence of tryptone (20 g/L, a combination of tryptone and meat extract (1:0.6, or tryptone and yeast extract (1:0.6. Growth of strain ST194BZ in the presence of 10 or 20 g/L of D-mannose yielded bacteriocin levels of 12 800 AU/mL. In the presence of 30 or 40 g/L of mannose the activity levels doubled to 25 600 AU/mL. No difference in antibacterial activity was recorded when strain ST194BZ was grown in the presence of 2 g/L of K2HPO4 and 2 g/L of KH2PO4. Concentrations of 10, 20 and 50 g/L of KH2PO4 yielded double activity (25 600 AU/mL. Supplementing MRS with 1 g/L or more glycerol inhibited the production of bacteriocin. Growth in the presence of vitamins did not stimulate bacteriocin production. No plasmids were recorded for strain ST194BZ, suggesting that the genes encoding bacteriocin production are located on the genome.

  19. Coproduction of colicin V and lactic acid bacteria bacteriocins in lactococci and enterococci strains of biotechnological interest.

    Science.gov (United States)

    Langa, S; Arqués, J L; Medina, M; Landete, J M

    2017-05-01

    The aim of this study was the coproduction in a single strain of the Gram-negative bacteriocin colicin V with other bacteriocins from lactic acid bacteria (LAB). Colicin V was expressed in Lactococcus and Enterococcus strains by replacing the colicin V leader peptide by the leader peptide and promoter of d-alanyl-d-alanine carboxypeptidase from Lactobacillus reuteri CECT925 in pNZ8048 (pNZ:LR-colV). The antimicrobial activity of colicin V against the indicator organism Escherichia coli DH5α in transformed strains was checked by agar diffusion assay and SDS-PAGE analysis. Lactococcus and Enterococcus transformed with pNZ:LR-colV were able to coproduce colicin V at high levels together with other LAB bacteriocins such as nisin A, nisin Z, lacticin 481 or enterocins A and B, obtaining broad-spectrum activity strains with large potential applications. The construction showed in this work could be used for the heterologous expression of other bacteriocins active against Gram-negative bacteria or wide-spectrum bacteriocins from LAB. © 2017 The Society for Applied Microbiology.

  20. LIKE IT ACID AND POOR: A STUDY OF ABIOTIC FACTORS INFLUENCING Streptococcus bovis HC5 GROWTH AND BACTERIOCIN PRODUCTION

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    Ana Andréa Teixeira Barbosa

    2015-04-01

    Full Text Available This study aimed to investigate the effect of pH, temperature, growth atmosphere and nutrient availability on bovicin HC5 production by Streptococcus bovis HC5. S. bovis HC5 grew well in complex and basal media under aerobic and anaerobic conditions, but greater bacteriocin yields were recovered from anaerobic cultures. Lactate production and glucose consumption increased if S. bovis HC5 cells were cultivated at pH 7.0 and at 45 ºC, but higher bovicin HC5 activity was recovered from cells grown in acidic conditions and at lower temperatures (39 ºC. Cultures maintained under continuous CO2 flow showed faster growth rates in basal media, but bacteriocin production was always higher if S. bovis was cultivated in anaerobic sealed tubes. These results suggest that acidic pH and anoxic conditions favor bovicin HC5 production by S. bovis HC5. S. bovis HC5 is a unique lactic acid bacterium in its ability to grow and produce high amounts of a potentially useful bacteriocin in simple media. Considering the constrains for bacteriocin production at commercial scale, it appears that bovicin HC5 production could be achieved at lower costs compared to other bacteriocins from lactic acid bacteria.

  1. Purification and Characterization of Bacteriocin Produced by Bacillus subtilis R75 Isolated from Fermented Chunks of Mung Bean (Phaseolus radiatus

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    Riti Kapoor

    2011-01-01

    Full Text Available Food-grade bacteria capable of producing bacteriocin with desirable preservation attributes have been isolated from traditional Indian fermented food dal vari, which has not been investigated so far. Among different isolates, Bacillus subtilis R75, isolated on MRS agar, exhibited antagonism against a wide range of foodborne pathogens that cause serious spoilage. Extracellularly produced bacteriocin was purified by single step gel exclusion column chromatography. The purity rate and molecular mass of 12 kDa of this compound were determined using SDS-PAGE. Activity units (AU of bacteriocin were increased in each step of purification, reaching up to 5·10^6 AU/mL. The increase in the activity units directly affected the antimicrobial activity of purified bacteriocin, resulting in an increase up to 200, 333 and 175 % of the inhibition zones against indicator bacteria. Continuous decrease in the number of viable cells of microorganisms within 10 h after adding purified bacteriocin proved its bactericidal action. It withstood very high temperature, up to 121 °C, for 10 min, wider pH range, from 4.0 to 11.0, complete inactivation in the presence of proteolytic enzymes and storage stability up to 2.5 months.

  2. A putative amino acid transporter determines sensitivity to the two-peptide bacteriocin plantaricin JK.

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    Oppegård, Camilla; Kjos, Morten; Veening, Jan-Willem; Nissen-Meyer, Jon; Kristensen, Tom

    2016-08-01

    Lactobacillus plantarum produces a number of antimicrobial peptides (bacteriocins) that mostly target closely related bacteria. Although bacteriocins are important for the ecology of these bacteria, very little is known about how the peptides target sensitive cells. In this work, a putative membrane protein receptor of the two-peptide bacteriocin plantaricin JK was identified by comparing Illumina sequence reads from plantaricin JK-resistant mutants to a crude assembly of the sensitive wild-type Weissella viridescens genome using the polymorphism discovery tool VAAL. Ten resistant mutants harbored altogether seven independent mutations in a gene encoding an APC superfamily protein with 12 transmembrane helices. The APC superfamily transporter thus is likely to serve as a target for plantaricin JK on sensitive cells. © 2016 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  3. A strain-variable bacteriocin in Bacillus anthracis and Bacillus cereus with repeated Cys-Xaa-Xaa motifs

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    Haft Daniel H

    2009-04-01

    Full Text Available Abstract Bacteriocins are peptide antibiotics from ribosomally translated precursors, produced by bacteria often through extensive post-translational modification. Minimal sequence conservation, short gene lengths, and low complexity sequence can hinder bacteriocin identification, even during gene calling, so they are often discovered by proximity to accessory genes encoding maturation, immunity, and export functions. This work reports a new subfamily of putative thiazole-containing heterocyclic bacteriocins. It appears universal in all strains of Bacillus anthracis and B. cereus, but has gone unrecognized because it is always encoded far from its maturation protein operon. Patterns of insertions and deletions among twenty-four variants suggest a repeating functional unit of Cys-Xaa-Xaa. Reviewers This article was reviewed by Andrei Osterman and Lakshminarayan Iyer.

  4. Alternatives for biosurfactants and bacteriocins extraction from Lactococcus lactis cultures produced under different pH conditions.

    Science.gov (United States)

    Rodríguez, N; Salgado, J M; Cortés, S; Domínguez, J M

    2010-08-01

    Study of the potential of Lactococcus lactis CECT-4434 as a biosurfactants and nisin (the only bacteriocin allowed to be used in the food industry) producer for industrial applications, exploiting the possibility of recovering separately both metabolites, taking into account that L. lactis is an interesting micro-organism with several applications in the food industry because it is recognized as GRAS. The results showed the ability of this strain to produce cell-bound biosurfactants, under controlled pH, and cell-bound biosurfactants and bacteriocins, when pH was not controlled. Three extraction procedures were designed to separately recover these substances. The strain L. lactis CECT-4434 showed to be a cell-bound biosurfactants and bacterocins producer when fermentations were carried out under uncontrolled pH. Both products can be recovered separately. Development of a convenient tool for the extraction of cell-bound biosurfactants and bacteriocins from the fermentation broth.

  5. Influence of culture media, pH and temperature on growth and bacteriocin production of bacteriocinogenic lactic acid bacteria.

    Science.gov (United States)

    Yang, En; Fan, Lihua; Yan, Jinping; Jiang, Yueming; Doucette, Craig; Fillmore, Sherry; Walker, Bradley

    2018-01-24

    There has been continued interest in bacteriocins research from an applied perspective as bacteriocins have potential to be used as natural preservative. Four bacteriocinogenic lactic acid bacteria (LAB) strains of Lactobacillus curvatus (Arla-10), Enterococcus faecium (JFR-1), Lactobacillus paracasei subsp. paracasei (JFR-5) and Streptococcus thermophilus (TSB-8) were previously isolated and identified in our lab. The objective of this study was to determine the optimal growth conditions for both LAB growth and bacteriocins production. In this study, various growth conditions including culture media (MRS and BHI), initial pH of culture media (4.5, 5.5, 6.2, 7.4 and 8.5), and incubation temperatures (20, 37 and 44 °C) were investigated for LAB growth measured as optical density (OD), bacteriocin activity determined as arbitrary unit and viability of LAB expressed as log CFU ml -1 . Growth curves of the bacteriocinogenic LAB were generated using a Bioscreen C. Our results indicated that Arla-10, JFR-1, and JFR-5 strains grew well on both MRS and BHI media at growth temperature tested whereas TSB-8 strain, unable to grow at 20 °C. LAB growth was significantly affected by the initial pH of culture media (p < 0.001) and the optimal pH was found ranging from 6.2 to 8.5. Bacteriocin activity was significantly different in MRS versus BHI (p < 0.001), and the optimal condition for LAB to produce bacteriocins was determined in MRS broth, pH 6.2 at 37 °C. This study provides useful information on potential application of bacteriocinogenic LAB in food fermentation processes.

  6. Purification and partial characterization of bacillocin 490, a novel bacteriocin produced by a thermophilic strain of Bacillus licheniformis

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    De Felice Maurilio

    2002-04-01

    Full Text Available Abstract Background Applications of bacteriocins as food preservatives have been so far limited, principally because of their low antimicrobial activity in foods. Nisin is the only bacteriocin of significant use, but applications are restricted principally because of its very low activity at neutral or alkaline pH. Thus the isolation of new bacteriocins active in foods is desirable. Results We isolated a Bacillus licheniformis thermophilic strain producing a bacteriocin with some novel features, named here bacillocin 490. This bacteriocin was inactivated by pronase E and proteinase K and was active against closely related Bacillus spp. both in aerobic and in anaerobic conditions. Bactericidal activity was kept during storage at 4°C and was remarkably stable in a wide pH range. The bacteriocin was partially purified by elution after adhesion to cells of the food-isolated strain Bacillus smithii and had a rather low mass (2 KDa. Antimicrobial activity against B. smithii was observed also when this organism was grown in water buffalo milk. Conclusions Bacillocin 490 is a novel candidate as a food anti-microbial agent since it displays its activity in milk, is stable to heat treatment and during storage, is active in a wide pH range and has bactericidal activity also at high temperature. These features may allow the use of bacillocin 490 during processes performed at high temperature and as a complementary antimicrobial agent of nisin against some Bacillus spp. in non-acidic foods. The small size suggests its use on solid foods.

  7. Induction of bacteriocin production by coculture is widespread among plantaricin-producing Lactobacillus plantarum strains with different regulatory operons.

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    Maldonado-Barragán, Antonio; Caballero-Guerrero, Belén; Lucena-Padrós, Helena; Ruiz-Barba, José Luis

    2013-02-01

    We describe the bacteriocin-production phenotype in a group of eight singular bacteriocinogenic Lactobacillus plantarum strains with three distinct genotypes regarding the plantaricin locus. Genotyping of these strains revealed the existence of two different plantaricin-production regulatory operons, plNC8-plNC8HK-plnD or plnABCD, involving three-component systems controlled each of them by a specific autoinducer peptide (AIP), i.e. PLNC8IF or PlnA. While all of the strains produced antimicrobial activity when growing on solid medium, most of them halted this production when cultured in broth, thus reflecting the functionality of regulatory mechanisms. Antimicrobial activity in broth cultures was re-established or enhanced when the specific AIP was added to the culture or by coculturing with specific bacterial strains. The latter trait appeared to be widespread in bacteriocinogenic L. plantarum strains independently of the regulatory system used to regulate bacteriocin production or the specific bacteriocins produced. The induction spectrum through coculture, i.e. the pattern of bacterial strains able to induce bacteriocin production, was characteristic of each individual L. plantarum strain. Also, the ability of some bacteria to induce bacteriocin production in L. plantarum by coculture appeared to be strain specific. The fact that induction of bacteriocin production by coculturing appeared to be a common feature in L. plantarum can be exploited accordingly to enhance the viability of this species in food and feed fermentations, as well as to contribute to probiotic functionality when colonising the gastrointestinal tract. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Lactobacillus pentosus B231 Isolated from a Portuguese PDO Cheese: Production and Partial Characterization of Its Bacteriocin.

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    Guerreiro, Joana; Monteiro, Vitor; Ramos, Carla; Franco, Bernadette Dora Gombossy de Melo; Martinez, Rafael Chacon Ruiz; Todorov, Svetoslav Dimitrov; Fernandes, Paulo

    2014-06-01

    Bacteriocin B231 produced by Lactobacillus pentosus, isolated from an artisanal raw cow's milk protected designation of origin Portuguese cheese, is a small protein with an apparent relative mass of about 5 kDa and active against a large number of Listeria monocytogenes wild-type strains, Listeria ivanovii and Listeria innocua. Bacteriocin B231 production is highly dependent on the type of the culture media used for growth of Lact. pentosus B231. Replacement of glucose with maltose yielded the highest bacteriocin production from eight different carbon sources. Similar results were recorded in the presence of combination of glucose and maltose or galactose. Production of bacteriocin B231 reached maximal levels of 800 AU/ml during the stationary phase of growth of Lact. pentosus B231 in MRS broth at 30 °C. Bacteriocin B231 (in cell-free supernatant) was sensitive to treatment with trypsin and proteinase K, but not affected by the thermal treatment in range of 55-121 °C, or freezing (-20 °C). Bacteriocin production and inhibitory spectrum were evaluated. Gene encoding plantaricin S has been detected in the genomic DNA. Virulence potential and safety of Lact. pentosus B231 were assessed by PCR targeted the genes gelE, hyl, asa1, esp, cylA, efaA, ace, vanA, vanB, hdc1, hdc2, tdc and odc. The Lact. pentosus B231 strains harbored plantaricin S gene, while the occurrence of virulence, antibiotic resistance and biogenic amine genes was limited to cytolysin, hyaluronidase, aggregation substance, adhesion of collagen protein, gelatinase, tyrosine decarboxylase and vancomycin B genes.

  9. Bacteriocin production and inhibition of Listeria monocytogenes by Lactobacillus sakei subsp. sakei 2a in a potentially synbiotic cheese spread.

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    Martinez, Rafael Chacon Ruiz; Staliano, Cristina Dini; Vieira, Antonio Diogo Silva; Villarreal, Martha Lissete Morales; Todorov, Svetoslav Dimitrov; Saad, Susana Marta Isay; Franco, Bernadette Dora Gombossy de Melo

    2015-06-01

    Survival, bacteriocin(s) production, and antilisterial effect of Lactobacillus sakei subsp. sakei 2a were evaluated in a potentially synbiotic cheese spread, throughout storage at 4 °C and 15 °C for up to 28 days, using culture-dependent (plate count) and culture-independent (qPCR) methods. Bacteriocin(s) production in the food product was monitored by phenotypic and molecular (RT-qPCR) techniques. Three cheese spread trials (T) containing the prebiotic fiber inulin were produced in duplicates and studied: T1 (control - without inoculation of lactic acid bacteria); T2 (inoculated with the non-bacteriocinogenic Lb. sakei ATCC 15521 strain), and T3 (inoculated with the bacteriocinogenic Lb. sakei 2a strain). The cheese spreads were challenged with Listeria monocytogenes serotypes 4b and 1/2a, individually added to the food product. The counts of Lb. sakei 2a in the cheese spread T3 remained high during storage and the growth of L. monocytogenes was inhibited at both temperatures, especially L. monocytogenes 4b in the food product kept at 15 °C due to the production of bacteriocins (up to 6,400 AU/mL). Expression of the genes sakP and sakQ encoding for bacteriocins production during the cheese spread storage was demonstrated. Lb. sakei 2a can be used for production of potentially synbiotic cheese spreads with increased safety. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Purification and amino acid sequence of a bacteriocins produced by Lactobacillus salivarius K7 isolated from chicken intestine

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    Kenji Sonomoto

    2006-03-01

    Full Text Available A bacteriocin-producing strain, Lactobacillus K7, was isolated from a chicken intestine. The inhibitory activity was determined by spot-on-lawn technique. Identification of the strain was performed by morphological, biochemical (API 50 CH kit and molecular genetic (16S rDNA basis. Bacteriocin purification processes were carried out by amberlite adsorption, cation exchange and reverse-phase high perform- ance liquid chromatography. N-terminal amino acid sequences were performed by Edman degradation. Molecular mass was determined by electrospray-ionization (ESI mass spectrometry (MS. Lactobacillus K7 showed inhibitory activity against Lactobacillus sakei subsp. sakei JCM 1157T, Leuconostoc mesenteroides subsp. mesenteroides JCM 6124T and Bacillus coagulans JCM 2257T. This strain was identified as Lb. salivarius. The antimicrobial substance was destroyed by proteolytic enzymes, indicating its proteinaceous structure designated as a bacteriocin type. The purification of bacteriocin by amberlite adsorption, cation exchange, and reverse-phase chromatography resulted in only one single active peak, which was designated FK22. Molecular weight of this fraction was 4331.70 Da. By amino acid sequence, this peptide was homology to Abp 118 beta produced by Lb. salivarius UCC118. In addition, Lb. salivarius UCC118 produced 2-peptide bacteriocin, which was Abp 118 alpha and beta. Based on the partial amino acid sequences of Abp 118 beta, specific primers were designed from nucleotide sequences according to data from GenBank. The result showed that the deduced peptide was high homology to 2-peptide bacteriocin, Abp 118 alpha and beta.

  11. Evaluation of leader peptides that affect the secretory ability of a multiple bacteriocin transporter, EnkT.

    Science.gov (United States)

    Sushida, Hirotoshi; Ishibashi, Naoki; Zendo, Takeshi; Wilaipun, Pongtep; Leelawatcharamas, Vichien; Nakayama, Jiro; Sonomoto, Kenji

    2018-02-13

    EnkT is a novel ATP-binding cassette (ABC) transporter responsible for secretion of four bacteriocins, enterocins NKR-5-3A, C, D, and Z (Ent53A, C, D, and Z), produced by Enterococcus faecium NKR-5-3. It is generally recognized that the secretion of a bacteriocin requires a dedicated ABC transporter, although molecular mechanisms of this secretion are yet to be revealed. In order to characterize the unique ability of EnkT to secrete multiple bacteriocins, the role of N-terminal leader peptides of bacteriocin precursors was evaluated using Ent53C precursor as a model. The 18-amino acid leader peptide of Ent53C (Lc) was modified by site-directed mutagenesis to generate various point mutations, truncations, or extensions, and substitutions with other leader peptides. The impact of these Lc mutations on Ent53C secretion was evaluated using a quantitative antimicrobial activity assay. We observed that Ent53C production increased with Ala substitution of the highly conserved C-terminal double glycine residues that are recognized as the cleavage site. In contrast, Ent53C antimicrobial activity decreased, with decrease in the length of the putative α-helix-forming region of Lc. Furthermore, EnkT recognized and transported Ent53C of the transformants possessing heterologous leader peptides of enterocin A, pediocin PA-1, brochocins A and B, and lactococcins Qα and Qβ. These results indicated that EnkT shows significant tolerance towards the sequence and length of leader peptides, to secrete multiple bacteriocins. This further demonstrates the functional diversity of bacteriocin ABC transporters and the importance of leader peptides as their recognition motif. Copyright © 2018 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  12. Complete genome sequence of Lactobacillus plantarum LZ95, a potential probiotic strain producing bacteriocins and B-group vitamin riboflavin.

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    Li, Ping; Gu, Qing

    2016-07-10

    Lactobacillus plantarum LZ95 is a potential probiotic isolated from newborn infant fecal and it is identified to produce riboflavin with great antimicrobial activity. The complete genome sequence of this strain was reported in the present study. The genome contains a 3,261,418-bp chromosome and two plasmids. Genes, related to the biosynthesis of bacteriocins and riboflavin, were identified. This work will facilitate to reveal the biosynthetic mechanism of bacteriocins and B-group vitamins in lactic acid bacteria and provide evidence for its potential application in food industry. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Ferredoxin containing bacteriocins suggest a novel mechanism of iron uptake in Pectobacterium spp.

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    Grinter, Rhys; Milner, Joel; Walker, Daniel

    2012-01-01

    In order to kill competing strains of the same or closely related bacterial species, many bacteria produce potent narrow-spectrum protein antibiotics known as bacteriocins. Two sequenced strains of the phytopathogenic bacterium Pectobacterium carotovorum carry genes encoding putative bacteriocins which have seemingly evolved through a recombination event to encode proteins containing an N-terminal domain with extensive similarity to a [2Fe-2S] plant ferredoxin and a C-terminal colicin M-like catalytic domain. In this work, we show that these genes encode active bacteriocins, pectocin M1 and M2, which target strains of Pectobacterium carotovorum and Pectobacterium atrosepticum with increased potency under iron limiting conditions. The activity of pectocin M1 and M2 can be inhibited by the addition of spinach ferredoxin, indicating that the ferredoxin domain of these proteins acts as a receptor binding domain. This effect is not observed with the mammalian ferredoxin protein adrenodoxin, indicating that Pectobacterium spp. carries a specific receptor for plant ferredoxins and that these plant pathogens may acquire iron from the host through the uptake of ferredoxin. In further support of this hypothesis we show that the growth of strains of Pectobacterium carotovorum and atrosepticum that are not sensitive to the cytotoxic effects of pectocin M1 is enhanced in the presence of pectocin M1 and M2 under iron limiting conditions. A similar growth enhancement under iron limiting conditions is observed with spinach ferrodoxin, but not with adrenodoxin. Our data indicate that pectocin M1 and M2 have evolved to parasitise an existing iron uptake pathway by using a ferredoxin-containing receptor binding domain as a Trojan horse to gain entry into susceptible cells.

  14. Ferredoxin containing bacteriocins suggest a novel mechanism of iron uptake in Pectobacterium spp.

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    Rhys Grinter

    Full Text Available In order to kill competing strains of the same or closely related bacterial species, many bacteria produce potent narrow-spectrum protein antibiotics known as bacteriocins. Two sequenced strains of the phytopathogenic bacterium Pectobacterium carotovorum carry genes encoding putative bacteriocins which have seemingly evolved through a recombination event to encode proteins containing an N-terminal domain with extensive similarity to a [2Fe-2S] plant ferredoxin and a C-terminal colicin M-like catalytic domain. In this work, we show that these genes encode active bacteriocins, pectocin M1 and M2, which target strains of Pectobacterium carotovorum and Pectobacterium atrosepticum with increased potency under iron limiting conditions. The activity of pectocin M1 and M2 can be inhibited by the addition of spinach ferredoxin, indicating that the ferredoxin domain of these proteins acts as a receptor binding domain. This effect is not observed with the mammalian ferredoxin protein adrenodoxin, indicating that Pectobacterium spp. carries a specific receptor for plant ferredoxins and that these plant pathogens may acquire iron from the host through the uptake of ferredoxin. In further support of this hypothesis we show that the growth of strains of Pectobacterium carotovorum and atrosepticum that are not sensitive to the cytotoxic effects of pectocin M1 is enhanced in the presence of pectocin M1 and M2 under iron limiting conditions. A similar growth enhancement under iron limiting conditions is observed with spinach ferrodoxin, but not with adrenodoxin. Our data indicate that pectocin M1 and M2 have evolved to parasitise an existing iron uptake pathway by using a ferredoxin-containing receptor binding domain as a Trojan horse to gain entry into susceptible cells.

  15. Control of tyramine and histamine accumulation by lactic acid bacteria using bacteriocin forming lactococci.

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    Tabanelli, Giulia; Montanari, Chiara; Bargossi, Eleonora; Lanciotti, Rosalba; Gatto, Veronica; Felis, Giovanna; Torriani, Sandra; Gardini, Fausto

    2014-11-03

    The aim of this study was to evaluate the competitive effects of three bacteriocin producing strains of Lactococcus lactis subsp. lactis against two aminobiogenic lactic acid bacteria, i.e. the tyramine producing strain Enterococcus faecalis EF37 and the histamine producing strain Streptococcus thermophilus PRI60, inoculated at different initial concentrations (from 2 to 6 log cfu/ml). The results showed that the three L. lactis subsp. lactis strains were able to produce bacteriocins: in particular, L. lactis subsp. lactis VR84 and EG46 produced, respectively, nisin Z and lacticin 481, while for the strains CG27 the bacteriocin has not been yet identified, even if its peptidic nature has been demonstrated. The co-culture of E. faecalis EF37 in combination with lactococci significantly reduced the growth potential of this aminobiogenic strain, both in terms of growth rate and maximum cell concentration, depending on the initial inoculum level of E. faecalis. Tyramine accumulation was strongly reduced when E. faecalis EF37 was inoculated at 2 log cfu/ml and, to a lesser extent, at 3 log cfu/ml, as a result of a lower cell load of the aminobiogenic strain. All the lactococci were more efficient in inhibiting streptococci in comparison with E. faecalis EF37; in particular, L. lactis subsp. lactis VR84 induced the death of S. thermophilus PRI60 and allowed the detection of histamine traces only at higher streptococci inoculum levels (5-6 log cfu/ml). The other two lactococcal strains did not show a lethal action against S. thermophilus PRI60, but were able to reduce its growth extent and histamine accumulation, even if L. lactis subsp. lactis EG46 was less effective when the initial streptococci concentration was 5 and 6 log cfu/ml. This preliminary study has clarified some aspects regarding the ratio between bacteriocinogenic strains and aminobiogenic strains with respect to the possibility to accumulate BA and has also showed that different bacteriocins can have

  16. Structure and properties of the metastable bacteriocin Lcn972 from Lactococcus lactis

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    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.

  17. Discovery of Azurin-Like Anticancer Bacteriocins from Human Gut Microbiome through Homology Modeling and Molecular Docking against the Tumor Suppressor p53

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    Chuong Nguyen

    2016-01-01

    Full Text Available Azurin from Pseudomonas aeruginosa is known anticancer bacteriocin, which can specifically penetrate human cancer cells and induce apoptosis. We hypothesized that pathogenic and commensal bacteria with long term residence in human body can produce azurin-like bacteriocins as a weapon against the invasion of cancers. In our previous work, putative bacteriocins have been screened from complete genomes of 66 dominant bacteria species in human gut microbiota and subsequently characterized by subjecting them as functional annotation algorithms with azurin as control. We have qualitatively predicted 14 putative bacteriocins that possessed functional properties very similar to those of azurin. In this work, we perform a number of quantitative and structure-based analyses including hydrophobic percentage calculation, structural modeling, and molecular docking study of bacteriocins of interest against protein p53, a cancer target. Finally, we have identified 8 putative bacteriocins that bind p53 in a same manner as p28-azurin and azurin, in which 3 peptides (p1seq16, p2seq20, and p3seq24 shared with our previous study and 5 novel ones (p1seq09, p2seq05, p2seq08, p3seq02, and p3seq17 discovered in the first time. These bacteriocins are suggested for further in vitro tests in different neoplastic line cells.

  18. The effectiveness of novel bacteriocin derived from Escherichia coli colonized in the fermented pineapple Ananas comosus (L. Merr. against pathogenic bacteria isolated from aquaculture sites

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    S. W. Lee

    2014-11-01

    Full Text Available Aim: The aim was to evaluate antimicrobial property of bacteriocin isolated from Escherichia coli against pathogenic bacteria from aquaculture sites. Materials and Methods: E. coli was isolated from fermented pineapple Ananas comosus using eosin methylene blue agar. The antimicrobial activity of the isolated E. coli was screened using hole-plate diffusion method. The bacterial strain that showed the widest inhibition zone was selected and grown in tryptic soy broth, followed by partial purification of bacteriocin by using ammonium sulphate. Bacteriocin derived from the E. coli was subjected to the antimicrobial test against 55 bacteria strains namely Aeromonas hydrophila (n=10, Citrobacter freundii (n=5, Edwardsiella tarda (n=10, Flavobacterium spp. (n=10, Pseudomonas spp. (n=10, Vibrio parahaemolyticus (n=5 and Vibrio alginolyticus (n=5 by using twofold broth microdilution method to determine minimum inhibitory concentration (MIC values of the bacteriocin against the tested bacteria. Results: The results of the present study showed that the MIC values of the partially purified bacteriocin against present pathogenic bacteria isolates ranged from 7.81 to 31.25 ppm whereas the MIC values of kanamycin (positive control ranged from 15.63 to 125 ppm. Conclusion: The results of the present study showed the bacteriocin derived from E. coli can control all the present bacterial isolates indicating the huge potential of the bacteriocin as a new antimicrobial agent for aquaculture uses.

  19. Combined effect of bacteriocin produced by Lactobacillus plantarum ST8SH and vancomycin, propolis or EDTA for controlling biofilm development by Listeria monocytogenes.

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    Todorov, Svetoslav D; de Paula, Otávio A L; Camargo, Anderson C; Lopes, Danilo A; Nero, Luís A

    2017-09-22

    The Listeria monocytogenes strains selected in the present study exhibited similar behavior in biofilm formation, independently of the tested conditions (bacteriocin from L. plantarum ST8SH, vancomycin, propolis (a natural antimicrobial product) and EDTA (chelating agent)), individual or in associations. The individual application of vancomycin had better inhibitory activity than that of propolis and EDTA; however, the association of the previously mentioned antimicrobial agents with bacteriocins resulted in better performance. However, when we compared the effects of vancomycin, propolis and EDTA, we could clearly observe that the combined application of bacteriocin and vancomycin was more effective than the combination of bacteriocin and propolis, and bacteriocin and EDTA. Considering the current need to reduce the use of antimicrobials and chemical substances in food processing, propolis can represent an alternative to improve the inhibitory effect of bacteriocins against L. monocytogenes biofilm formation, based on the obtained results. In general, high concentrations of bacteriocin produced by L. plantarum ST8SH were more effective in biofilm inhibition, and similar results were observed for vancomycin and propolis; however, all tested EDTA concentrations had similar effect on biofilm formation. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  20. Isolation of Lactic Acid Bacteria That Produce Protease and Bacteriocin-Like Substance From Mud Crab (Scylla sp. Digestive Tract (Isolasi Bakteri Asam Laktat yang Menghasilkan Protease dan Senyawa Bacteriocin-Like dari Saluran Pencernaan Kepiting

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    Heru Pramono

    2015-03-01

    Kata kunci: Bakteri Asam Laktat, Bakteriosin-like substance, Protease, Scylla  sp. Digestive tract is complex environment consist of large amount of bacteria’s species. Fish intestine bacteria consist of aerobic or facultative anaerob bacteria which can produce antibacterial and enzym. The objectives of this research were to isolated lactic acid bacteria that produce bacteriocin-like and protease from mud crab digestive tract. Isolation and characterization of isolates were conducted employing media MRS.  Neutralized cell free supernatant of isolates were tested using disc diffusion agar of against pathogenic and spoilage bacteria to indicate bacteriocin-like-producing lactic acid bacteria. Protease-producing isolate was tested using disc diffusion method in casein agar. Among a hundred isolates, 96 isolates were showed clear zone in MRS+CaCO3,, catalase negative, and Gram positive bacteria. Thirty four isolates produced protease and only four isolates (i.e. IKP29, IKP30, IKP52, and IKP94 showed strong inhibition against pathogenic and spoilage bacteria. There were three patterns of inhibition among three isolates against Bacillus subtilis, Staphylococcus aureus, Eschericia coli, and Salmonella sp. All three isolates showed potential uses for produce starter culture for fishery product fermentation purpose. This is the first report of isolation lactic acid bacteria that produced protease and bacteriocin-like from digestive tract of mud crab. Keywords: Lactic acid bacteria, Bacteriocin-like substance, Protease, Scylla  sp.

  1. EKSTRAKSI DAN KARAKTERISASI BAKTERIOSIN YANG DIHASILKAN OLEH Leuconostoc mesenteroides SM 22 [Extraction and Characterization of Bacteriocin Produced by Leuconostoc mesenteroides SM 22

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    Darnawan Ari Nugroho

    2003-12-01

    Full Text Available Bacteriocin produced by lactic acid bacteria has potential as food biopreservative due to their capability to control spoilage and pathogenic food borne bacteria. Previous studies showed that extraction of bacteriocin produced by Leuconostoc mesenteroides SM 22 using adsorption-desorption method was not optimal. The objectives of this research were (1 to increase the effectiveness of bacteriocin extraction using adsorption-desorption method by the addition of heated biomass of Leuconostoc SM 22 in various concentration during adsorbtion (2 to characterize the bacteriocin of Leuconostoc mesenteroides SM 22 on it's stability during heat treatment, during cool storage and it's spectrum activity againts pathogenic bacteria. Result of this research showed that bacteriocin activity obtained from extraction with no addition of heated biomass was 1000 AU/ml, while by addition of heated biomass of 2 to 3 times of original concentration (OD were 2000 AU/ml. Therefore it was suggested that addition of heated biomass of Leuconostoc mesenteroides SM 22 during adsorption-desorption with 2 times of original concentration (OD was able to increase the bacteriocin obtained. Bacteriocin with original activity of 2000 AU/ml, was stable (no reduction activity after heated at 100oC for 30 minutes, but slightly decrease after heated at 121oC for 5 minutes and 121oC for 15 minutes, that were 1600 AU/ml and 800 AU/ml respectively. Bacteriocin of Leuconostoc mesenteroides SM 22 was stable during 8 weeks storage at refrigerator (4oC, freezer -20oC and -40oC. This bacteriocin has a wide spectrum of activity showed by it's ability to inhibit the growth of Listeria monocytogenes, Staphylococcus aureus, Salmonella thypimurium, Vibrio parahaemolyticus, Shigella and psychrophilic bacteria isolated from milk and isolated from meat.

  2. SCREENING OF LACTIC ACID BACTERIA FROM SUDANESE FERMENTED FOODS FOR BACTERIOCIN PRODUCTION

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    Yasmeen Y. A. Elyas

    2015-04-01

    Full Text Available Forty isolates of lactic acid bacteria (LAB were isolated from different types of fermented foods consumed in Sudan. Phenotypic tests revealed that all isolates were homofermentative LAB. Twenty-four isolates produced inhibitory substances primarily active against Staphylococcus aureus ATCC 2818 and Escherichia coli ATCC 29522. The inhibitory activity of 88% of enterococci and 58% of lactobacilli was recorded from meat isolates, whereas all activity of pediococcal isolates came from fermented milk isolates. The cell-free cultures of 18 isolates exhibiting inhibitory activity was chosen for further investigation such as sensitivity to proteolytic enzyme (pepsin, effect of heat treatment (60°C for 60min, 100°C for 20min and 121°C for 15min and effect of pH ( pH 2.0, pH 6.5, and pH 9.0. The inhibitory activity was eliminated upon treatment with pepsin. The bacteriocin-like substances lost their activity after heating at all temperatures used and at alkaline pH (9.0, whereas they were active at acidic pH (2.0. The antimicrobial activity of bacteriocin-like substances produced by the isolated LAB could prevent spoilage and/or pathogenic microorganism in Sudanese fermented food. Further study should be related with species identification of the producer strains and with the purification and characterization of these becteriocin-like substances in order to explore them in food industry.

  3. Bacteriocin-Producing Enterococcus faecium LCW 44: A High Potential Probiotic Candidate from Raw Camel Milk

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    Allison Vimont

    2017-05-01

    Full Text Available Bacterial isolates from raw camel milk were screened for antibacterial activity using the agar diffusion assay. Ten isolates selected for their inhibition of Gram-positive bacteria were identified by 16S sequencing as Enterococcus faecium or durans. An isolate named E. faecium LCW 44 exhibited the broadest antibacterial spectrum with an inhibitory activity against several Gram-positive strains belonging to the genera Clostridium, Listeria, Staphylococcus, and Lactobacillus. E. faecium LCW 44 was shown to produce N-formylated enterocins L50A and L50B, as revealed by mass spectrometry and PCR analyses. This isolate did not harbor any of the virulence factors tested and was shown to be sensitive to all tested antibiotics. It showed high resistance to gastric and intestinal conditions (78 ± 4% survival. Its adhesion index was evaluated at 176 ± 86 and 24 ± 86 on Caco-2 cells and HT-29 cells, respectively, and it significantly reduced adhesion of Listeria monocytogenes by 65 and 49%, respectively. In Macfarlane broth (simulating the nutrient content of the colon, counts of L. monocytogenes were reduced by 2 log10 cycles after 24 h in co-culture with E. faecium LCW 44, compared to the increase of 4 log10 cycles when cultured alone. Comparison with a bacteriocin-non-producing mutant of E. faecium LCW 44 strongly suggests that inhibition of L. monocytogenes was due to bacteriocin production. Altogether, E. faecium LCW 44 thus has potential for use as a probiotic for humans and veterinary medicine.

  4. In vitro evaluation of the probiotic potential of bacteriocin producer Lactobacillus sakei 1.

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    Gomes, Bruna C; Rodrigues, Marina R; Winkelströter, Lizziane K; Nomizo, Auro; de Martinis, Elaine C P

    2012-06-01

    Lactobacillus sakei 1 is a food isolate that produces a heat-stable antimicrobial peptide (sakacin 1, a class IIa bacteriocin) inhibitory to the opportunistic pathogen Listeria monocytogenes. Bacterial isolates with antimicrobial activity may be useful for food biopreservation and also for developing probiotics. To evaluate the probiotic potential of L. sakei 1, it was tested for (i) in vitro gastric resistance (with synthetic gastric juice adjusted to pH 2.0, 2.5, or 3.0); (ii) survival and bacteriocin production in the presence of bile salts and commercial prebiotics (inulin and oligofructose); (iii) adhesion to Caco-2 cells; and (iv) effect on the adhesion of L. monocytogenes to Caco-2 cells and invasion of these cells by the organism. The results showed that L. sakei 1 survival in gastric environment varied according to pH, with the maximum survival achieved at pH 3.0, despite a 4-log reduction of the population after 3 h. Regarding the bile salt tolerance and influence of prebiotics, it was observed that L. sakei 1 survival rates were similar (P > 0.05) for all de Man Rogosa Sharpe (MRS) broth formulations when tests were done after 4 h of incubation. However, after incubation for 24 h, the survival of L. sakei 1 in MRS broth was reduced by 1.8 log (P pH-neutralized supernatant containing sakacin 1 led to a significant reduction of in vitro listerial invasion of human intestinal Caco-2 cells.

  5. Bacteriocin-Producing Enterococcus faecium LCW 44: A High Potential Probiotic Candidate from Raw Camel Milk.

    Science.gov (United States)

    Vimont, Allison; Fernandez, Benoît; Hammami, Riadh; Ababsa, Ahlem; Daba, Hocine; Fliss, Ismaïl

    2017-01-01

    Bacterial isolates from raw camel milk were screened for antibacterial activity using the agar diffusion assay. Ten isolates selected for their inhibition of Gram-positive bacteria were identified by 16S sequencing as Enterococcus faecium or durans . An isolate named E. faecium LCW 44 exhibited the broadest antibacterial spectrum with an inhibitory activity against several Gram-positive strains belonging to the genera Clostridium , Listeria , Staphylococcus , and Lactobacillus. E. faecium LCW 44 was shown to produce N-formylated enterocins L50A and L50B, as revealed by mass spectrometry and PCR analyses. This isolate did not harbor any of the virulence factors tested and was shown to be sensitive to all tested antibiotics. It showed high resistance to gastric and intestinal conditions (78 ± 4% survival). Its adhesion index was evaluated at 176 ± 86 and 24 ± 86 on Caco-2 cells and HT-29 cells, respectively, and it significantly reduced adhesion of Listeria monocytogenes by 65 and 49%, respectively. In Macfarlane broth (simulating the nutrient content of the colon), counts of L. monocytogenes were reduced by 2 log 10 cycles after 24 h in co-culture with E. faecium LCW 44, compared to the increase of 4 log 10 cycles when cultured alone. Comparison with a bacteriocin-non-producing mutant of E. faecium LCW 44 strongly suggests that inhibition of L. monocytogenes was due to bacteriocin production. Altogether, E. faecium LCW 44 thus has potential for use as a probiotic for humans and veterinary medicine.

  6. Fructooligosaccharides metabolism and effect on bacteriocin production in Lactobacillus strains isolated from ensiled corn and molasses.

    Science.gov (United States)

    Muñoz, M; Mosquera, A; Alméciga-Díaz, C J; Melendez, A P; Sánchez, O F

    2012-06-01

    Fructo- (FOS) and galacto-oligosaccharides have been used to promote the growth of probiotics, mainly those from Lactobacillus genus. However, only few reports have evaluated the effect of prebiotics on bacteriocins activity and production. In this work, we characterized the effect of FOS supplementation on the growth, lactic and acetic acids production, and antimicrobial activity of crude extracts obtained from Lactobacillus strains isolated from ensiled corn and molasses. Seven out of 28 isolated Lactobacillus, belonging to Lactobacillus casei, Lactobacillus plantarum, and Lactobacillus brevis, showed antimicrobial activity against Listeria innocua. Among them, the strain L. plantarum LE5 showed antimicrobial activity against Listeria monocytogenes and Enteroccocus faecalis; while the L. plantarum LE27 strain showed antimicrobial effect against L. monocytogenes, E. faecalis, Escherichia coli and Salmonella enteritidis. This antimicrobial activity in most of the cases was obtained only after FOS supplementation. In summary, these results show the feasibility to increase the antimicrobial activity of Lactobacillus bacteriocins by supplementing the growth medium with FOS. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Properties of Bac W42, a bacteriocin produced by Bacillus subtilis W42 isolated from Cheonggukjang.

    Science.gov (United States)

    Kindoli, Salum; Lee, Hwang A; Kim, Jeong Hwan

    2012-08-01

    Ten Bacillus strains with antimicrobial activities were isolated from Cheonggukjang produced at different parts in Korea. They all inhibited Listeria monocytogenes ATCC 19111 and nine inhibited Bacillus cereus ATCC 14579. Four isolates (W42, H27, SKE 12, and K21) showing strong inhibiting activities were identified as B. subtilis. B. subtilis W42 was the most inhibiting strain. The antimicrobial activity of culture supernatant from B. subtilis W42 was destroyed completely by proteinase K treatment, indicating that a bacteriocin was the responsible agent. The bacteriocin, Bac W42, was most stable at pH 7 and stable between pH 3-6 and 8-9. Bac W42 was stable up to 80°C. BHI (brain heart infusion) and TSB (tryptic soy broth) were the best media for the activity (320 AU/ml) followed by LB (160 AU/ml). Bac W42 was partially purified by column chromatographies. The specific activity was increased from 1,151.2 AU/ml to 9,043.5 AU/ml and the final yield was 26.3%. Bac W42 was 5.4 kDa in size as determined by SDS-PAGE. Bac W42 showed bactericidal activity against L. monocytogenes ATCC 19111.

  8. Genotypic and Phylogenic Analysis of Lactobacilli Producing Bacteriocin Isolated from Traditional Dairy Products and Food

    Directory of Open Access Journals (Sweden)

    Frazaneh Tafvizi

    2012-09-01

    Full Text Available Background & Objective: Lactic acid bacteria (LAB are a group of Gram-positive, non-spore forming, cocci or rod shaped, catalase negative organisms, considered as Generally Recognized as Safe (GRAS organisms. These bacteria are used for thousands of years for production of fermented foods because of their ability to produce desirable changes in taste, flavor and texture. Different antimicrobial molecules such as bacteriocins produced by these bacteria that can inhibit food pathogens, so enhancing the shelf life and improving the safety of food products. Because of important role of LAB to improving the human health, molecular identification and phylogenic analysis of these bacteria based on 16S rRNA sequencing play the critical role in investigation of local sources of LAB in Iran. Materials & Methods: 5 isolates were selected from 20 isolates for molecular identification. These strains produced the high level of bacteriocin. Total genomic DNA was extracted by lysosyme extraction protocol. PCR-mediated amplification was carried out by degenerate primers. Sequencing was performed after purification of PCR product. Results: Isolates were deposited as novel strains of Lactobacillus casei and Entrococcus facium in GenBank. Conclusion: Because of high potential of local probiotic bacteria in Iran, these strains may be useful and could be used in the food industry.

  9. Bacteriocin-Producing Enterococcus faecium LCW 44: A High Potential Probiotic Candidate from Raw Camel Milk

    Science.gov (United States)

    Vimont, Allison; Fernandez, Benoît; Hammami, Riadh; Ababsa, Ahlem; Daba, Hocine; Fliss, Ismaïl

    2017-01-01

    Bacterial isolates from raw camel milk were screened for antibacterial activity using the agar diffusion assay. Ten isolates selected for their inhibition of Gram-positive bacteria were identified by 16S sequencing as Enterococcus faecium or durans. An isolate named E. faecium LCW 44 exhibited the broadest antibacterial spectrum with an inhibitory activity against several Gram-positive strains belonging to the genera Clostridium, Listeria, Staphylococcus, and Lactobacillus. E. faecium LCW 44 was shown to produce N-formylated enterocins L50A and L50B, as revealed by mass spectrometry and PCR analyses. This isolate did not harbor any of the virulence factors tested and was shown to be sensitive to all tested antibiotics. It showed high resistance to gastric and intestinal conditions (78 ± 4% survival). Its adhesion index was evaluated at 176 ± 86 and 24 ± 86 on Caco-2 cells and HT-29 cells, respectively, and it significantly reduced adhesion of Listeria monocytogenes by 65 and 49%, respectively. In Macfarlane broth (simulating the nutrient content of the colon), counts of L. monocytogenes were reduced by 2 log10 cycles after 24 h in co-culture with E. faecium LCW 44, compared to the increase of 4 log10 cycles when cultured alone. Comparison with a bacteriocin-non-producing mutant of E. faecium LCW 44 strongly suggests that inhibition of L. monocytogenes was due to bacteriocin production. Altogether, E. faecium LCW 44 thus has potential for use as a probiotic for humans and veterinary medicine. PMID:28572793

  10. Bacteriocin- producing strain of Enterococcus faecium EK 13 with probiotic character and its application in the digestive tract of rabbits

    Czech Academy of Sciences Publication Activity Database

    Lauková, A.; Strompfová, V.; Skřivanová, V.; Volek, Z.; Jindřichová, E.; Marounek, Milan

    2006-01-01

    Roč. 61, č. 6 (2006), s. 779-782 ISSN 0006-3088. [ Probiotic Conference /2./. Košice, 15.09.2006-19.09.2006] Grant - others:VEGA 2/5139/25 Institutional research plan: CEZ:AV0Z50450515 Keywords : probiotic * bacteriocin * enterocin Subject RIV: GH - Livestock Nutrition Impact factor: 0.213, year: 2006

  11. Characterization of Bacteriocin like inhibitory substance produced by a new Strain Brevibacillus borstelensis AG1 Isolated from 'Marcha'

    Directory of Open Access Journals (Sweden)

    Nivedita Sharma

    2014-09-01

    Full Text Available In the present study, a bacterium isolated from Marcha- a herbal cake used as traditional starter culture to ferment local wine in North East India, was evaluated for bacteriocin like inhibitory substance production and was tested against six food borne/spoilage causing pathogens viz. Listeria monocytogenes MTCC 839, Bacillus subtilis MTCC 121, Clostridium perfringens MTCC 450, Staphylococcus aureus, Lactobacillus plantarum and Leuconostoc mesenteroides MTCC 107 by using bit/disc method followed by well diffusion method. The bacterial isolate was identified as Brevibacillus borstelensis on the basis of phenotypic, biochemical and molecular characteristics using 16Sr RNA gene technique. Bacteriocin like inhibitory substance produced by Brevibacillus borstelensis AG1 was purified by gel exclusion chromatography. The molecular mass of the Brevibacillus borstelensis AG1 was found to be 12 kDa. Purified bacteriocin like inhibitory substance of Brevibacillus borstelensis was further characterized by studying the effect of temperature, pH, proteolytic enzyme and stability. Bacteriocin like inhibitory substance was found to be thermostable upto 100 °C, active at neutral pH, sensitive to trypsin, and partially stable till third week of storage thus showing a bright prospective to be used as a potential food biopreservative.

  12. Antimicrobial and Anti-Swarming Effects of Bacteriocins and Biosurfactants from Probiotic Bacterial Strains against Proteus spp.

    Directory of Open Access Journals (Sweden)

    Laila Goudarzi

    2017-02-01

    Full Text Available Background:   Proteus spp. belongs to the family of Enterobacteriaceae. These bacteria are Gram-negative and motile microorganisms and known as the third most common causes of urinary tract infections. The aim of the current study was to investigate the effects of some secondary metabolites from probiotic strains of Lactobacillus spp. on swarming and growth of Proteus mirabilis and P. vulgaris. Methods:   After determination of optimal conditions for the growth and production of antimicrobials, bacteriocins and biosurfactants were partially purified from Lactobacillus culture supernatants. Then, effects of the purified compounds on growth and swarming migration of Proteus spp. were examined in the presence of various concentrations of semi-purified compounds. Results:  Results showed that the partially purified bacteriocins inhibited Proteus spp. swarming distance and had a significant reduction on the bacterial growth curves. Biosurfactants in a solvent form did not have any considerable effects on factors produced by Proteus spp. Conclusion:  According to the results, the secondary metabolites, especially bacteriocins or bacteriocin-like substances derived from Lactobacillus strains, can inhibit or reduce growth and swarming migration of Proteus spp. which are considered as the bacteria major virulence factors.

  13. Potential use of Bacillus thuringiensis bacteriocins to control antibiotic-resistant bacteria associated with mastitis in dairy goats.

    Science.gov (United States)

    Gutiérrez-Chávez, A J; Martínez-Ortega, E A; Valencia-Posadas, M; León-Galván, M F; de la Fuente-Salcido, N M; Bideshi, D K; Barboza-Corona, J E

    2016-01-01

    Mastitis caused by microbial infections in dairy goats reduces milk yield, modifies milk composition, and potentially contributes to morbidity in herds and consumers of dairy products. Microorganisms associated with mastitis in dairy goats are commonly controlled with antibiotics, but it is known that continued use of these chemical agents promotes antibiotic resistance among bacterial populations. Recently, it has been shown that bacteriocins of Bacillus thuringiensis inhibit growth of food-borne pathogens and also bacteria associated with bovine mastitis. However, there is no report on their ability to inhibit microorganisms linked to mastitis in dairy goats. In this study, using 16S rDNA and ITS regions of rDNA, we identified nine bacterial isolates and an encapsulated yeast associated with mastitis in dairy goats. Enterococcus durans, Brevibacillus sp., and Staphylococcus epidermidis 2 were resistant to, respectively, 75, ~67, ~42, and ~42 % of the antibiotics screened. In addition, 60 % of the bacterial isolates were resistant to penicillin, ampicillin, vancomycin, and dicloxacillin. Importantly, 60 % of the isolates were inhibited by the bacteriocins, but S. epidermidis 1, Enterobacter sp., Escherichia vulneris, and Cryptococcus neoformans were not susceptible to these antimicrobial peptides. Using Brevibacillus sp. and Staphylococcus chromogenes as indicator bacteria, we show that peptides of ~10 kDa that correspond to the molecular mass of bacteriocins used in this study are responsible for the inhibitory activity. Our results demonstrate that multiple antibiotic-resistant bacteria associated with subclinical mastitis in dairy goats from Guanajuato, Mexico, are susceptible to bacteriocins produced by B. thuringiensis.

  14. In vitro evaluation of bacteriocin-like inhibitory substances produced by lactic acid bacteria isolated during traditional Sicilian cheese making

    Directory of Open Access Journals (Sweden)

    Giusi Macaluso

    2016-02-01

    Full Text Available Bacteriocins are antimicrobial proteins produced by bacteria that inhibit the growth of other bacteria with a bactericidal or bacteriostatic mode of action. Many lactic acid bacteria (LAB produce a high diversity of different bacteriocins. Bacteriocinogenic LAB are generally recognised as safe (GRAS and useful to control the frequent development of pathogens and spoilage microorganisms. For this reason they are commonly used as starter cultures in food fermentations. In this study, the authors describe the results of a screening on 699 LAB isolated from wooden vat surfaces, raw milk and traditional Sicilian cheeses, for the production of bacteriocin-like inhibitory substances, by comparing two alternative methods. The antagonistic activity of LAB and its proteinaceous nature were evaluated using the spot-on-the-lawn and the well-diffusion assay (WDA and the sensitivity to proteolytic (proteinase K, protease B and trypsin, amylolytic (α-amylase and lipolytic (lipase enzymes. The indicator strains used were: Listeria monocytogenes, Staphylococcus aureus, Escherichia coli, Salmonella enteritidis. A total of 223 strains (belonging to the species Enterococcus spp., Lactobacillus spp., Pediococcus spp., Streptococcus spp., Leuconostoc spp. and Lactococcus lactis were found to inhibit the growth of Listeria monocytogenes by using the spot-on-the-lawn method; only 37 of these were confirmed by using the WDA. The direct addition of bacteriocin-producing cultures into dairy products can be a more practical and economic option for the improvement of the safety and quality of the final product.

  15. PRODUCTION OF BACTERIOCIN EC2 AND ITS INTERFERENCE IN THE GROWTH OF SALMONELLA TYPHI IN A MILK MATRIX

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    Yuri de Jesus Lopes de Abreu

    2013-08-01

    Full Text Available Bacterial interference can occur through various mechanisms, including the production of peroxides, acids, ammonia, bacteriolytic enzymes or bacteriocins. The strain Escherichia coli EC2 produces the antimicrobial substance (AMS EC2, able to inhibit different strains of Gram-negative bacteria isolated from food, as E. coli and Salmonella sp. The activity of AMS EC2 was lost after treatment with proteolytic enzymes, indicating the presence of an active proteinaceous compound, suggesting that it is a bacteriocin. The substance, renamed bacteriocin EC2, has its better production when the producer strain is grown on Casoy medium, at 37ºC and pH 6.0, without NaCl addition, but it is also able to be produced in milk. When co-cultivated in UHT milk with the producer strain E. coli EC2, the growth of the indicator strain Salmonella Typhi is totally inhibited within the first 4 hours of incubation, suggesting a potential application of bacteriocin EC2 in the control of Salmonella sp. e.g. in foods.

  16. In vitro evaluation of the antimicrobial effect of a raw bacteriocin extract in combination with chemical preservatives employed in meat industry

    Directory of Open Access Journals (Sweden)

    Luis A. Aguado Bautista

    2010-12-01

    Full Text Available Biopreservation can be defined as the foods shelf life extension employing antibacterial products like bacteriocins. The objective of this work was to determinate the efficacy of E. faecium MXVK29 bacteriocin in combination with chemical preservatives against spoilage and pathogens microorganisms. Bacteriocin raw extrac antimicrobial activity was 46.34 UA/g of protein. Growth of Pseudomonas putida was not affected by the preservatives employed at the conditions employed. Antimicrobial response was different for other microorganisms since a synergetic effect of the preservatives combination inhibited Brochothrix thermosphacta and Escherichia coli growth. Sodium lactate had additive effect only against Listeria innocua.

  17. Factors affecting production of an antilisterial bacteriocin by Carnobacterium piscicola strain A9b in laboratory media and model fish systems

    DEFF Research Database (Denmark)

    Himelbloom, B.; Nilsson, Lilian; Gram, Lone

    2001-01-01

    in APT broth when a low inoculum level (0.001%) was used. In contrast, inoculum level did not influence bacteriocin production in BHI and MRS7 without glucose. Bacteriocin production in APT was induced by the presence of an extracellular compound present in the sterile, filtered, cell- free supernatant...... fluid of a stationary-phase culture. Increasing concentrations of NaCl (2-7%) reduced bacteriocin production and maximum cell density of C. piscicola A9b when grown in cooked fish juice at VC. Conclusions: Media composition, inoculum level and sodium chloride concentration affected production...

  18. Leuconostoc carnosum 4010 has the potential for use as a protective culture for vacuum-packed meats: culture isolation, bacteriocin identification, and meat application experiments

    DEFF Research Database (Denmark)

    Budde, B.B.; Hornbæk, T.; Jacobsen, T.

    2003-01-01

    A new culture, Leuconostoc carnosum 4010, for biopreservation of vacuum-packed meats is described. The culture originated from bacteriocin-producing lactic acid bacteria (LAB) naturally present in vacuum-packed meat products. Approximately, 72,000 colonies were isolated from 48 different vacuum...... culture for cold-stored, cooked, sliced, and vacuum-packed meat products.......-packed meat products and examined for antibacterial activity. Bacteriocin-producing colonies were isolated from 46% of the packages examined. Leuc. carnosum was the predominant bacteriocin-producing strain and Leuc. carnosum 4010 was selected for further experiments because it showed strong antilisterial...

  19. Characterization, N-terminal sequencing and classification of Tolworthcin 524: A bacteriocin produced by Bacillus thuringiensis subsp. tolworthi.

    Science.gov (United States)

    Pacheco-Cano, Rubén D; de la Fuente-Salcido, Norma M; Salcedo-Hernández, Rubén; León-Galván, M Fabiola; Bideshi, Dennis K; Hernández-Guzmán, Gustavo; Barboza-Corona, J Eleazar

    2014-12-01

    Bacteriocins synthesized by entomopathogenic Bacillus thuringiensis are gaining attention owing to their inhibitory effects against a wide variety of pathogenic bacteria. In the present study, we purified and characterized Tolworthcin 524, a bacteriocin synthesized by B. thuringiensis subsp. tolworthi, and compared it with other bacteriocins synthesized by B. thuringiensis. Tolworthcin 524 was separated and purified from the secretome of B. thuringiensis by fast protein liquid chromatography with a gel filtration column to obtain yields of 17% and a specific activity of ∼3600U/mgprotein. The purified product showed two peptides of ∼9 and 6kDa with antimicrobial activity in a gel-screening assay. The purified product was analyzed by two-dimensional electrophoresis and the resolved peptides of ∼9 and 6kDa with isoelectric points of ∼8 were sequenced. Partial sequences (METPVVQPR and DWTCWSCLVCAACS) were obtained suggesting that the ∼9 and 6kDa correspond to the prebacteriocin and mature Tolworthcin 524, respectively. Sequences showed high identity with Thurincin H and Thuricin 17 and had a conserved motif with other bacteriocins of B. thuringiensis. Based on sequence data, Tolworthcin 524 was classified in subclass II.2 (Thuricin-like peptides) of the Bacillus bacteriocin classification scheme. The larger peptide did not harbor a sequence suggestive of a signal peptide neither did it contain the double-glycine (GG) motif characteristic of the secretion leader recognized by the ABC transport system. Implications of these properties in Tolworthcin 524 secretion are discussed. Copyright © 2014 Elsevier GmbH. All rights reserved.

  20. Exploration and conservation of bacterial genetic resources as bacteriocin producing inhibitory microorganisms to pathogen bacteria in livestock

    Directory of Open Access Journals (Sweden)

    Chotiah S

    2013-06-01

    Full Text Available Exploration and conservation of microorganisms producing bacteriocin was done as the primary study towards the collection of potential bacteria and its application in improving livestock health condition and inhibit food borne pathogens. Diferent kinds of samples such as beef cattle rectal swab, rumen fluids, cow’s milk, chicken gut content, goat’s milk were collected at Bogor cattle slaughter houses, poultry slaughter houses, dairy cattle and goat farms. A total of 452 bacterial isolates consisted of 73 Gram negative bacteria and 379 Gram positive bacteria were isolated from samples collected and screened for bacteriocin activity. Determination of bacteriocin activity with bioassay using agar spot tests were carried out on liquid and semisolid medium assessing 8 kins of indicators of pathogenic bacteria and food borne pathogens. A total of 51 bacteriocin producing strains were collected and some of the strains had high inhibitory zone such as Lactobacillus casei SS14C (26 mm, Enterobacter cloacae SRUT (24mm, Enterococcus faecalis SK39 (21mm and Bifidobacterium dentium SS14T (20mm respectively, to Salmonella typhimurium BCC B0046/ATCC 13311, E. coli O157 hemolytic BCC B2717, Listeria monocytogenes BCC B2767/ATCC 7764 and Escherichia coli VTEC O157 BCC B2687. Evaluation after conservation ex situ to all bacterocin producing strain at 5oC for 1 year in freeze drying ampoules in vacuum and dry condition revealed the decreasing viability starting from log 0.8 CFU/ml for Lactococcus and Leuconostoc to log 2.2. CFU/ml for Streptococcus. Result of the study showed that the bacteriocin producing strains obtained were offered a potential resource for preventing disease of livestock and food borne diseases.

  1. Short communication: culture-independent detection of lactic Acid bacteria bacteriocin genes in two traditional slovenian raw milk cheeses and their microbial consortia.

    Science.gov (United States)

    Trmcić, A; Obermajer, T; Rogelj, I; Bogovic Matijasić, B

    2008-12-01

    Two Slovenian traditional raw milk cheeses, Tolminc (from cows' milk) and Kraski (from ewes' milk), were examined for the presence of 19 lactic acid bacteria bacteriocin genes by PCR analysis of total DNA extracts from 9 cheeses and from consortia of strains isolated from these cheeses. Eleven bacteriocin genes were detected in at least one cheese or consortium, or from both. Different cheeses or consortia contained 3 to 9 bacteriocin determinants. Plantaricin A gene determinants were found in all cheese and consortia DNA extracts. Genes for enterocins A, B, P, L50A, and L50B, and the bacteriocin cytolysin were commonly detected, as were genes for nisin. These results indicate that bacteriocinogenic strains of Lactobacillus, Enterococcus, and Lactococcus genera with protective potential are common members of indigenous microbiota of raw milk cheeses, which can be a good source of new protective strains.

  2. Bacteriocins: molecules of fundamental impact on the microbial ecology and potential food biopreservatives

    Directory of Open Access Journals (Sweden)

    Evandro Leite de Souza

    2005-07-01

    Full Text Available Bacteriocins are proteic molecules synthesized for various lineages of Gram-positive and Gram-negative bacteria when exposed to stressful conditions. Bacteriocins have been characterized as molecules of high antimicrobial property even at low concentrations, provoking the microbial survival inhibition by antibiosis. These substances have their synthesis mediated for genetic mechanisms and develop their lethal action on the microbial cell by multiples mechanisms that can act of isolated or concomitant way culminating with microbial cell killing. This molecules class presents characteristic of stability to heat, low pH, refrigeration and freezing, and resistance to weak organics solvents, salts and enzymes. On the other hand, they are very sensitive to proteolytic enzymes action. Bacteriocins could appear as potential agents to be applied in food conservation systems in order to provide microbiologically stable foods.Bacteriocinas são moléculas protéicas sintetizadas por várias linhagens de bactérias Gram-positivas e Gram-negativas quando submetidas a condições de stress. São ainda caracterizadas como moléculas de alto poder antimicrobiano mesmo em baixas concentrações, provocando a inibição da sobrevivência microbiana através de uma ação de antibiose. As bacteriocinas têm seu processo de síntese mediado por mecanismos genéticos, e desenvolvem sua ação letal sobre a célula microbiana por intermédio de múltiplos mecanismos que podem agir de forma isolada ou concomitante culminando com a morte da célula microbiana. Estas moléculas apresentam características de estabilidade ao calor, baixo pH, refrigeração, congelamento, resistência a ácidos orgânicos fracos, sais e enzimas, porém são muito sensíveis à enzimas proteolíticas. Assim, as bacteriocinas podem aparecer como potenciais agentes para serem aplicados em sistemas de conservação de alimentos com objetivo de prover alimentos microbiologicamente estáveis.

  3. Biochemical and Genetic Characterization of Coagulin, a New Antilisterial Bacteriocin in the Pediocin Family of Bacteriocins, Produced by Bacillus coagulans I4

    Science.gov (United States)

    Le Marrec, Claire; Hyronimus, Bertrand; Bressollier, Philippe; Verneuil, Bernard; Urdaci, Maria C.

    2000-01-01

    A plasmid-linked antimicrobial peptide, named coagulin, produced by Bacillus coagulans I4 has recently been reported (B. Hyronimus, C. Le Marrec and M. C. Urdaci, J. Appl. Microbiol. 85:42–50, 1998). In the present study, the complete, unambiguous primary amino acid sequence of the peptide was obtained by a combination of both N-terminal sequencing of purified peptide and the complete sequence deduced from the structural gene harbored by plasmid I4. Data revealed that this peptide of 44 residues has an amino acid sequence similar to that described for pediocins AcH and PA-1, produced by different Pediococcus acidilactici strains and 100% identical. Coagulin and pediocin differed only by a single amino acid at their C terminus. Analysis of the genetic determinants revealed the presence, on the pI4 DNA, of the entire 3.5-kb operon of four genes described for pediocin AcH and PA-1 production. No extended homology was observed between pSMB74 from P. acidilactici and pI4 when analyzing the regions upstream and downstream of the operon. An oppositely oriented gene immediately dowstream of the bacteriocin operon specifies a 474-amino-acid protein which shows homology to Mob-Pre (plasmid recombination enzyme) proteins encoded by several small plasmids extracted from gram-positive bacteria. This is the first report of a pediocin-like peptide appearing naturally in a non-lactic acid bacterium genus. PMID:11097892

  4. Streptococcal Bacteriocin-Like Inhibitory Substances: Some Personal Insights into the Bacteriocin-Like Activities Produced by Streptococci Good and Bad.

    Science.gov (United States)

    Tagg, John Robert

    2009-06-01

    The background to the discovery and commercial development of the first Streptococcus salivarius probiotic is documented. A 40-year search of the genus Streptococcus for a harmless natural antagonist of Streptococcus pyogenes had as its operational basis a simple deferred antagonism "fingerprinting" procedure, the application of which results in each tested strain being accorded an inhibitor production (P)-type and inhibitor sensitivity (S)-type profile. Systematic application of this schema has opened a "Pandora's Box" of novel streptococcal bacteriocin-like inhibitory substances (BLIS). The numerically prominent commensal S. salivarius is proposed to have a pivotal population-modulating role within the oral microbiota of humans. The probiotic strain S. salivarius K12 produces several megaplasmid-encoded BLIS including the lantibiotics salivaricin A and salivaricin B. Strain K12 and other BLIS-producing S. salivarius are currently in use or under development for application to the control of a variety of common maladies and infections of the human oral cavity.

  5. Bacteriocin production, antibiotic susceptibility and prevalence of haemolytic and gelatinase activity in faecal lactic acid bacteria isolated from healthy Ethiopian infants.

    Science.gov (United States)

    Birri, Dagim Jirata; Brede, Dag Anders; Tessema, Girum Tadesse; Nes, Ingolf F

    2013-02-01

    The objective of this study was to characterise lactic acid bacteria (LAB) isolated from faecal samples of healthy Ethiopian infants, with emphasis on bacteriocin production and antibiotic susceptibility. One hundred fifty LAB were obtained from 28 healthy Ethiopian infants. The isolates belonged to Lactobacillus (81/150), Enterococcus (54/150) and Streptococcus (15/150) genera. Lactobacillus species were more abundant in the breast-fed infants while Enterococcus dominated the mixed-fed population. Bacteriocin-producing LAB species were isolated from eight of the infants. Many different bacteriocins were identified, including one new bacteriocin from Streptococcus salivarius, avicin A (class IIa) from Enterococcus avium, one class IIa bacteriocin from Enterococcus faecalis strains, one unknown bacteriocin from E. faecalis and two unknown bacteriocins from Lactobacillus fermentum strains and the two-peptide gassericin T from Lactobacillus gasseri isolate. Susceptibility tests performed for nine antibiotics suggest that some lactobacilli might have acquired resistance to erythromycin (3 %) and tetracycline (4 %) only. The streptococci were generally antibiotic sensitive except for penicillin, to which they showed intermediate resistance. All enterococci were susceptible to ampicillin while 13 % showed penicillin resistance. Only one E. faecalis isolate was vancomycin-resistant. Tetracycline (51 %) and erythromycin (26 %) resistance was prevalent among the enterococci, but multidrug resistance was confined to E. faecalis (47 %) and Enterococcus faecium (33 %). Screening of enterococcal virulence traits revealed that 2 % were β-haemolytic. The structural genes of cytolysin were detected in 28 % of the isolates in five enterococcal species, the majority being E. faecalis and Enterococcus raffinosus. This study shows that bacteriocin production and antibiotic resistance is a common trait of faecal LAB of Ethiopian infants while virulence factors occur at low levels.

  6. Spatial attributes of the four-helix bundle group of bacteriocins – The high-resolution structure of BacSp222 in solution

    KAUST Repository

    Nowakowski, Michał

    2017-11-01

    BacSp222 is a multifunctional bacteriocin produced by Staphylococcus pseudintermedius strain 222, an opportunistic pathogen of domestic animals. At micromolar concentrations, BacSp222 kills Gram-positive bacteria and is cytotoxic toward mammalian cells, while at nanomolar doses, it acts as an immunomodulatory factor, enhancing nitric oxide release in macrophage-like cell lines. The bacteriocin is a cationic, N-terminally formylated, 50-amino-acid-long linear peptide that is rich in tryptophan residues.In this study, the solution structure of BacSp222 was determined and compared to the currently known structures of similar bacteriocins. BacSp222 was isolated from a liquid culture medium in a uniformly 13C- and 15N-labeled form, and NMR data were collected. The structure was calculated based on NMR-derived constraints and consists of a rigid and tightly packed globular bundle of four alpha-helices separated by three short turns.Although the amino acid sequence of BacSp222 has no significant similarity to any known peptide or protein, a 3D structure similarity search indicates a close relation to other four-helix bundle-motif bacteriocins, such as aureocin A53, lacticin Q and enterocins 7A/7B. Assuming similar functions, biology, structure and physicochemical properties, we propose to distinguish the four-helix bundle bacteriocins as a new Type A in subclass IId of bacteriocins, containing linear, non-pediocin-like peptides.

  7. Medical and Personal Care Applications of Bacteriocins Produced by Lactic Acid Bacteria

    Science.gov (United States)

    Dicks, L. M. T.; Heunis, T. D. J.; van Staden, D. A.; Brand, A.; Noll, K. Sutyak; Chikindas, M. L.

    The frequent use of antibiotics has led to a crisis in the antibiotic ­resistance of pathogens associated with humans and animals. Antibiotic resistance and the emergence of multiresistant bacterial pathogens have led to the investigation of alternative antimicrobial agents to treat and prevent infections in both humans and animals. Research on antimicrobial peptides, with a special interest on bacteriocins of lactic acid bacteria, is entering a new era with novel applications other than food preservation. Many scientists are now focusing on the application of these peptides in medicinal and personal care products. However, it is difficult to assess the success of such ventures due to the dearth of information that has been published and the lack of clinical trials.

  8. Transcription activation of a UV-inducible Clostridium perfringens bacteriocin gene by a novel sigma factor.

    Science.gov (United States)

    Dupuy, Bruno; Mani, Nagraj; Katayama, Seiichi; Sonenshein, Abraham L

    2005-02-01

    Expression of the plasmid-encoded Clostridium perfringens gene for bacteriocin BCN5 was shown to depend in vivo and in vitro on the activity of UviA protein. UviA, also plasmid-encoded, proved to be an RNA polymerase sigma factor and was also partly autoregulatory. The uviA gene has two promoters; one provided a UviA-independent, basal level of gene expression while the stronger, UviA-dependent promoter was only utilized after the cell experienced DNA damage. As a result, BCN5 synthesis is induced by treatment with UV light or mitomycin C. UviA is related to a special class of sigma factors found to date only in Clostridium species and responsible for activating transcription of toxin genes in Clostridium difficile, Clostridium tetani, and Clostridium botulinum.

  9. Stimulating Effects of Sucrose and Inulin on Growth, Lactate, and Bacteriocin Productions by Pediococcus pentosaceus.

    Science.gov (United States)

    de Souza de Azevedo, Pamela Oliveira; Converti, Attilio; Domínguez, José Manuel; de Souza Oliveira, Ricardo Pinheiro

    2017-12-01

    Sucrose and inulin, when combined with glucose, behaved as stimulating agents of bacteriocin production by Pediococcus pentosaceus ATCC 43200. When such microbial strain was grown in glucose-based Man, Rogosa, and Sharpe (MRS) medium, without any additional supplement, it showed higher maximum cell concentration (2.68 ± 1.10 g/L) and longer generation time (2.17 ± 0.02 h), but lower specific growth rate (0.32 ± 0.01 h -1 ) than in the same medium supplemented with 1.0% of both ingredients (2.53 ± 1.10 g/L, 1.60 ± 0.05 h and 0.43 ± 0.02 h -1 , respectively). Glucose replacement by sucrose or inulin almost completely suppressed growth, hence confirming that it is the preferred carbon source for this strain. Qualitatively, similar results were observed for lactate production, which was 59.8% higher in glucose-based medium. Enterococcus and Listeria strains were sensitive to bacteriocin, whose antimicrobial effect after 8 h increased from 120.25 ± 0.35 to 144.00 ± 1.41 or 171.00 ± 1.41 AU/mL when sucrose or inulin was added to the glucose-based MRS medium. Sucrose and inulin were also able to speed up P. pentosaceus growth in the exponential phase.

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

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    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.

  11. In silico analysis of protein toxin and bacteriocins from Lactobacillus paracasei SD1 genome and available online databases.

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    Komwit Surachat

    Full Text Available Lactobacillus paracasei SD1 is a potential probiotic strain due to its ability to survive several conditions in human dental cavities. To ascertain its safety for human use, we therefore performed a comprehensive bioinformatics analysis and characterization of the bacterial protein toxins produced by this strain. We report the complete genome of Lactobacillus paracasei SD1 and its comparison to other Lactobacillus genomes. Additionally, we identify and analyze its protein toxins and antimicrobial proteins using reliable online database resources and establish its phylogenetic relationship with other bacterial genomes. Our investigation suggests that this strain is safe for human use and contains several bacteriocins that confer health benefits to the host. An in silico analysis of protein-protein interactions between the target bacteriocins and the microbial proteins gtfB and luxS of Streptococcus mutans was performed and is discussed here.

  12. Bacteriocin-like inhibitory activities of seven Lactobacillus delbrueckii subsp. bulgaricus strains against antibiotic susceptible and resistant Helicobacter pylori strains.

    Science.gov (United States)

    Boyanova, L; Gergova, G; Markovska, R; Yordanov, D; Mitov, I

    2017-12-01

    The aim of the study was to detect anti-Helicobacter pylori activity of seven Lactobacillus delbrueckii subsp. bulgaricus (GLB) strains by four cell-free supernatant (CFS) types. Activity of non-neutralized and non-heat-treated (CFSs1), non-neutralized and heat-treated (CFSs2), pH neutralized, catalase-treated and non-heat-treated (CFSs3), or neutralized, catalase- and heat-treated (CFSs4) CFSs against 18 H. pylori strains (11 of which with antibiotic resistance) was evaluated. All GLB strains produced bacteriocin-like inhibitory substances (BLISs), the neutralized CFSs of two GLB strains inhibited >81% of test strains and those of four GLB strains were active against >71% of antibiotic resistant strains. Two H. pylori strains were BLIS resistant. The heating did not reduce the CFS activity. Briefly, all GLB strains evaluated produced heat-stable BLISs, although GLB and H. pylori strain susceptibility patterns exhibited differences. Bacteriocin-like inhibitory substance activity can be an advantage for the probiotic choice for H. pylori infection control. In this study, anti-Helicobacter pylori activity of seven Lactobacillus delbrueckii subsp. bulgaricus (GLB) strains was evaluated by four cell-free supernatant (CFS) types. The GLB strains produced heat-stable bacteriocin-like inhibitory substances (BLISs) with a strong anti-H. pylori activity and some neutralized, catalase- and heat-treated CFSs inhibited >83% of the test strains. Bacteriocin-like inhibitory substance production of GLB strains can render them valuable probiotics in the control of H. pylori infection. © 2017 The Society for Applied Microbiology.

  13. Evaluation of Potential Probiotic Properties of Enterococcus mundtii, Its Survival in Boza and in situ Bacteriocin Production

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    Svetoslav D. Todorov

    2009-01-01

    Full Text Available Boza is a low-pH and low-alcohol cereal-based beverage produced in the Balkan Peninsula. Barley was cooked and prepared according to a traditional recipe and inoculated with Enterococcus mundtii ST4V (a potential probiotic and bacteriocin-producing strain, commercially produced boza, Saccharomyces cerevisiae, and a combination of strain E. mundtii ST4V and Saccharomyces cerevisiae. Fermentation was carried out at 37 °C for 3 h. The organoleptic properties of fermented products were evaluated by a qualified taste panel. No significant differences in rheological properties were observed, suggesting that E. mundtii ST4V had no effect on the quality of the final product. Microbial cell numbers remained relatively unchanged during one week of storage. The preservative properties of bacteriocin ST4V were evaluated by contaminating boza with Lactobacillus sakei DSM 20017. Changes in microbial populations were monitored by using classical microbiological methods, PCR with species-specific primers and denaturing gradient gel electrophoresis (DGGE. Adsorption of bacteriocin ST4V to target cells is pH-dependent, with the highest adsorption (88 % recorded at pH=8.0 and pH=10.0. Maximum adsorption of bacteriocin ST4V (75 % to Enterococcus faecalis and Listeria innocua was recorded at 25 to 37 °C. Growth of E. mundtii ST4V was inhibited only by a few antibiotics and anti-inflammatory medicaments, suggesting that the strain may be used as a probiotic by individuals receiving medical treatment.

  14. Potential of bacteriocin-producing lactic acid bacteria for safety improvements of traditional Thai fermented meat and human health.

    Science.gov (United States)

    Swetwiwathana, Adisorn; Visessanguan, Wonnop

    2015-11-01

    Lactic acid bacteria (LAB) are very important in converting of agricultural products into safe, delicious and shelf stable foods for human consumption. The preservative activity of LAB in foods is mainly attributed to the production of anti-microbial metabolites such as organic acids and bacteriocins which enables them to grow and control the growth of pathogens and spoilage microorganisms. Besides ensuring safety, bacteriocin-producing LAB with their probiotic potentials could also be emerging as a means to develop functional meat products with desirable health benefits. Nevertheless, to be qualified as a candidate probiotic culture, other prerequisite probiotic properties of bacteriocin-producing LAB have to be assessed according to regulatory guidelines for probiotics. Nham is an indigenous fermented sausage of Thailand that has gained popularity and acceptance among Thais. Since Nham is made from raw meat and is usually consumed without cooking, risks due to undesirable microorganisms such as Salmonella spp., Staphylococcus aureus, and Listeria monocytogenes, are frequently observed. With an ultimate goal to produce safer and healthier product, our research attempts on the development of a variety of new Nham products are discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Lactic acid bacteria isolated from artisanal dry sausages: characterization of antibacterial compounds and study of the factors affecting bacteriocin production.

    Science.gov (United States)

    Castro, M P; Palavecino, N Z; Herman, C; Garro, O A; Campos, C A

    2011-04-01

    Lactic acid bacteria (LAB) were isolated from artisanal dry sausages sampled from north-eastern region of Chaco, Argentina. Among 141 isolates, 27 showed antimicrobial activity against Listeria innocua, Staphyloccus aureus or Brochothrix spp. One isolate, identified as Lb. curvatus/sakei, produced bacteriocin like substances (BLIS). These BLIS were heat stable, effective after refrigerated storage and freeze/thaw cycles and even active against pathogens when produced under refrigeration at 3% NaCl concentration. The influence of several factors on production of BLIS was assessed in MRS broth added with: EDTA, ascorbic acid, KCl, potassium sorbate, sodium citrate, 3 and 6% NaCl, Tween 20 or Brij 35. These additives showed different effects towards the effectiveness of the bacteriocin produced by Lb. sakei/curvatus against L. innocua and S. aureus. Conditions that provided high cell density favored high bacteriocin production. BLIS production by this LAB strain was greatly influenced by NaCl concentration and the presence of surfactants. © 2010 The American Meat Science Association. Published by Elsevier Ltd. All rights reserved.

  16. Inhibition of Listeria monocytogenes on Ready-to-Eat Meats Using Bacteriocin Mixtures Based on Mode-of-Action

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    Paul Priyesh Vijayakumar

    2017-03-01

    Full Text Available Bacteriocin-producing (Bac+ lactic acid bacteria (LAB comprising selected strains of Lactobacillus curvatus, Lactococcus lactis, Pediococcus acidilactici, and Enterococcus faecium and thailandicus were examined for inhibition of Listeria monocytogenes during hotdog challenge studies. The Bac+ strains, or their cell-free supernatants (CFS, were grouped according to mode-of-action (MOA as determined from prior studies. Making a mixture of as many MOAs as possible is a practical way to obtain a potent natural antimicrobial mixture to address L. monocytogenes contamination of RTE meat products (i.e., hotdogs. The heat resistance of the bacteriocins allowed the use of pasteurization to eliminate residual producer cells for use as post-process surface application or their inclusion into hotdog meat emulsion during cooking. The use of Bac+ LAB comprising 3× MOAs directly as co-inoculants on hotdogs was not effective at inhibiting L. monocytogenes. However, the use of multiple MOA Bac+ CFS mixtures in a variety of trials demonstrated the effectiveness of this approach by showing a >2-log decrease of L. monocytogenes in treatment samples and 6–7 log difference vs. controls. These data suggest that surface application of multiple mode-of-action bacteriocin mixtures can provide for an Alternative 2, and possibly Alternative 1, process category as specified by USDA-FSIS for control of L. monocytogenes on RTE meat products.

  17. Purification and characterization of a new Bacillus thuringiensis bacteriocin active against Listeria monocytogenes, Bacillus cereus and Agrobacterium tumefaciens.

    Science.gov (United States)

    Kamoun, Fakher; Fguira, Ines Ben; Hassen, Najeh Belguith Ben; Mejdoub, Hafedh; Lereclus, Didier; Jaoua, Samir

    2011-09-01

    This study reports on the identification, characterization and purification of a new bacteriocin, named Bacthuricin F103, from a Bacillus thuringiensis strain BUPM103. Bacthuricin F103 production began in the early exponential phase and reached a maximum in the middle of the same phase. Two chromatographic methods based on high performance liquid chromatography and fast protein liquid chromatography systems were used to purify Bacthuricin F103. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis revealed that this bacteriocin had a molecular weight of approximately 11 kDa. It also showed a wide range of thermostability of up to 80 °C for 60 min and a broad spectrum of antimicrobial activity over a pH range of 3.0-10.0. This bacteriocin was noted, and for the first time, to exhibit potent antimicrobial activity against Agrobacterium subsp. strains, the major causal agents of crown gall disease in tomato and vineyard crops, and against several challenging organisms in food, such as Listeria monocytogenes and Bacillus cereus. Complete killing with immediate impact on cells was observed within a short period of time. The sequence obtained for Bacthuricin F103 by direct N-terminal sequencing shared considerable homology with hemolysin. Bacthuricin F103 was noted to act through the depletion of intracellular ions, which suggest that the cell membrane was a possible target to Bacthuricin F103.

  18. The Leaderless Bacteriocin Enterocin K1 Is Highly Potent against Enterococcus faecium: A Study on Structure, Target Spectrum and Receptor

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    Kirill V. Ovchinnikov

    2017-05-01

    Full Text Available Enterocin K1 (EntK1, enterocin EJ97 (EntEJ97, and LsbB are three sequence related leaderless bacteriocins. Yet LsbB kills only lactococci while EntK1 and EntEJ97 target wider spectra with EntK1 being particularly active against Enterococcus faecium, including nosocomial multidrug resistant isolates. NMR study of EntK1 showed that it had a structure very similar to LsbB – both having an amphiphilic N-terminal α-helix and an unstructured C-terminus. The α-helix in EntK1 is, however, about 3–4 residues longer than that of LsbB. Enterococcal mutants highly resistant to EntEJ97 and EntK1 were found to have mutations within rseP, a gene encoding a stress response membrane-bound Zn-dependent protease. Heterologous expression of the enterococcal rseP rendered resistant cells of Streptococcus pneumoniae sensitive to EntK1 and EntEJ97, suggesting that RseP likely serves as the receptor for EntK1 and EntEJ97. It was also shown that the conserved proteolytic active site in E. faecalis RseP is partly required for EntK1 and EntEJ97 activity, since alanine substitutions of its conserved residues (HExxH reduced the sensitivity of the clones to the bacteriocins. RseP is known to be involved in bacterial stress response. As expected, the growth of resistant mutants with mutations within rseP was severely affected when they were exposed to higher (stressing growth temperatures, e.g., at 45°C, at which wild type cells still grew well. These findings allow us to design a hurdle strategy with a combination of the bacteriocin(s and higher temperature that effectively kills bacteriocin sensitive bacteria and prevents the development of resistant cells.

  19. Bacteriocin production of Lactobacillus sp. from intestines of ducks (Anas domesticus L.) incubated at room temperature and antibacterial effectivity against pathogen

    Science.gov (United States)

    Arfani, Nurfitri; Nur, Fatmawati; Hafsan, Azrianingsih, Rodiyati

    2017-05-01

    Bacteriocin is a peptide that is easily degraded by proteolytic enzymes in the digestive systems of animals, including humans. It has antimicrobial activity against pathogenic bacteria. Lactobacillus sp. is one type of lactic acid bacteria (LAB) that occupies the intestines of ducks (Anas domesticus L.). The purpose of this research was to determine the optimum time of the highest protein production by Lactobacillus sp. and to determine inhibitory activity of bacteriocin against pathogenic bacteria (Escherichia coli and Staphylococcus aureus). Using the Bradford method, the results showed that the optimum time of highest bacteriocin production was after 36 hours of incubation, with a protein content of 0.93 mg/ml. The bacteriocin inhibitory activity against Escherichia coli showed that a protein concentration of 30% gave a maximum inhibition index of 1.1 mm, while for Staphylococcus aureus, a concentration of 70% gave a maximum inhibition index of 0.3 mm. Further research is required to determine the stationary state of bacteriocin production in this circumstance.

  20. Characterization of Bacteriocin-Producing Lactic Acid Bacteria Isolated from Native Fruits of Ecuadorian Amazon.

    Science.gov (United States)

    Garzón, Karina; Ortega, Clara; Tenea, Gabriela N

    2017-12-04

    Tropical, wild-type fruits are considered biodiverse "hotspots" of microorganisms with possible functional characteristics to be investigated. In this study, several native lactic acid bacteria (LAB) of Ecuadorian Amazon showing highly inhibitory potential were identified and characterized. Based on carbohydrate fermentation profile and 16S rRNA gene sequencing, seven strains were assigned as Lactobacillus plantarum and one strain as Weissella confusa. Using agar-well diffusion method the active synthetized components released in the neutralized and hydroxide peroxide eliminated cell-free supernatant were inhibited by proteolytic enzymes, while the activity was maintained stable after the treatment with catalase, lysozyme, α-amylase and lipase suggesting their proteinaceous nature. The inhibitory activity was stimulated by acidic conditions, upon exposure to high heat and maintained stable at different ranges of sodium chloride (4-10%). The DNA sequencing analysis confirmed the presence of plw structural gene encoding for plantacirin W in the selected L. plantarum strains. Moreover, we showed that the active peptides of Cys5-4 strains contrast effectively, in a bactericidal manner, the growth of food borne E. coli UTNEc1 and Salmonella UTNSm2, with about tree fold reduction of viable counts at the early stage of the target cell growth. The results indicated that the bacteriocin produced by selected native lactic acid bacteria strains has elevated capacity to suppress several pathogenic microorganisms implying their potential as antimicrobial agents or food preservatives.

  1. Bacteriocin-like substance (BLS) production in Aeromonas hydrophila water isolates.

    Science.gov (United States)

    Messi, Patrizia; Guerrieri, Elisa; Bondi, Moreno

    2003-03-14

    30 Aeromonas hydrophila water isolates were tested for bacteriocin-like substance (BLS) production using a target panel of closely related microorganisms and other Gram-positive and Gram-negative bacteria, including food-borne pathogens. A. hydrophila showed antibacterial activity against one or more indicator microorganisms, but the activity emerged only with non-phylogenetically related genera or species. In particular all A. hydrophila showed antibacterial activity against one or more of the tested Staphylococcus strains, five against Listeria spp. (Listeria seeligeri, Listeria welshimeri and Listeria ivanovii), and eight presented a weak antagonistic activity towards Streptococcus agalactiae and Lactobacillus spp. Inhibitory activity was not observed against the other Gram-positive (Listeria monocytogenes, Listeria innocua and Enterococcus spp.) and Gram-negative tested strains, including Aeromonas sobria, Aeromonas caviae and the same A. hydrophila, when used as indicator. Anti-staphylococcal activity was observed with a gradual increase of the inhibition zone during incubation and seemed to be influenced by A. hydrophila hemolytic expression. Extrachromosomal analysis showed the presence, in 70% of the strains, of one to five plasmids with molecular masses ranging from 2.1 to 41.5 MDa, but it was not possible to relate this result with BLS production.

  2. Three-dimensional structure of the two-peptide bacteriocin plantaricin JK.

    Science.gov (United States)

    Rogne, Per; Haugen, Christofer; Fimland, Gunnar; Nissen-Meyer, Jon; Kristiansen, Per Eugen

    2009-09-01

    The three-dimensional structures of the two peptides, PlnJ and PlnK, that constitutes the two-peptide bacteriocin plantaricin JK have been solved in water/TFE and water/DPC-micellar solutions using nuclear magnetic resonance (NMR) spectroscopy. PlnJ, a 25 residue peptide, has an N-terminal amphiphilic alpha-helix between Trp-3 and Tyr-15. The 32 residues long PlnK forms a central amphiphilic alpha-helix between Gly-9 and Leu-24. Measurements of the effect on anti-microbial activity of single glycine replacements in PlnJ and PlnK show that Gly-13 and Gly-17 in both peptides are very sensitive, giving more than a 100-fold reduction in activity when large residues replace glycine. In variants where other glycine residues, Gly-20 in PlnJ and Gly-7, Gly-9, Gly-24 and Gly-25 in PlnK, were replaced, the activity was reduced less than 10-fold. It is proposed that the detrimental effect on activity when exchanging Gly-13 and Gly-17 in PlnJ and PlnK is a result of reduced ability of the two peptides to interact through the GxxxG-motifs constituting Gly-13 and Gly-17.

  3. Identification of a new Bacillus licheniformis strain producing a bacteriocin-like substance.

    Science.gov (United States)

    Guo, Yaoqi; Yu, Zhanqiao; Xie, Jianhua; Zhang, Rijun

    2012-06-01

    The emergence of antibiotic resistance has spurred a great number of studies for development of new antimicrobials in the past decade. The purpose of this study was to screen environmental samples for Bacillus strains producing potent antimicrobial agents. A new strain, which showed strong antimicrobial activity against Staphylococcus aureus and Salmonella enterica ser. Pullorum, was isolated from soil and designated as B116. This new isolate was identified as Bacillus licheniformis by morphological, biochemical and genetic analyses. The production of bacteriocin-like substance (BLS) started at early exponential phase and achieved highest level at early stationary phase. The BLS was precipitated by ammonium sulfate and its molecular mass was determined as ∼4 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Culture supernatant of the new isolate exhibited antimicrobial activity against both Gram-positive and Gram-negative bacteria, including Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, Micrococcus luteus, Escherichia coli, and Salmonella spp. The BLS was resistant to heat, acid and alkaline treatment. Activity of the BLS was totally lost after digestion by pronase and partially lost after digestion by papain and lipase. The new isolate and relevant BLS are potentially useful in food and feed applications.

  4. Influence of organic buffers on bacteriocin production by Streptococcus thermophilus ST110.

    Science.gov (United States)

    Somkuti, George A; Gilbreth, Stefanie E

    2007-08-01

    The effect of the organic buffer salts MES, MOPS, and PIPES on the growth of S. thermophilus ST110, medium pH, and accumulation of the antipediococcal bacteriocin thermophilin 110 were evaluated in whey permeate media over a period of 24 h. In nonbuffered medium, thermophilin 110 production at 37 degrees C paralleled the growth of S. thermophilus ST110 and reached a maximum after 8-10 h. Addition of organic buffer salts decreased the drop in medium pH and resulted in increased biomass (dry cells; microg/mL) and higher yields of thermophilin 110 (units/microg cells). The best results were obtained by the addition of 1% (w/v) MES to the medium, which reduced the pH drop to 1.8 units after 10 h of growth (compared to 2.3 pH units in the control) and resulted in a 1.5-fold increase in cell mass (495 microg/mL) and a 7-fold increase in thermophilin 110 yield (77 units/microg dry cells) over the control. The results showed that whey permeate-based media may be suitable for producing large amounts of thermophilin 110 needed for controlling spoilage pediococci in industrial wine and beer fermentations.

  5. Heterologous Expression of the Lactococcus lactis Bacteriocin, Nisin, in a Dairy Enterococcus Strain

    Science.gov (United States)

    Li, Haiping; O'Sullivan, Daniel J.

    2002-01-01

    The bacteriocin nisin is produced only by some strains of Lactococcus lactis, and to date production in other lactic acid bacteria has not been achieved. Enterococcus sp. strain N12β is a nisin-immune transconjugant obtained from a nisin-producing donor (L. lactis ATCC 11454) and a dairy recipient (Enterococcus sp. strain S12β), but it does not produce nisin. In this study, using PCR amplification, we confirmed that the whole nisin operon is likely present in Enterococcus sp. strain N12β. Northern hybridization of total RNA from strain N12β with a nisA probe and the results of reverse transcriptase PCR showed the lack of nisA transcription in this strain. However, nisA transcription was partially restored in strain N12β upon growth in the presence of exogenous nisin, and the nisA transcription signal was intensified after an increase in the external nisin level. Furthermore, bioassays showed that active nisin was produced in a dose-dependent fashion by strain N12β following induction by exogenous nisin. These results indicated that expression of the nisin genes in Enterococcus sp. strain N12β depended on autoinduction via signal transduction. However, the amount of external inducing signal required was significantly greater than the amount needed for autoinduction in L. lactis. PMID:12089020

  6. Lactic Acid Bacteria and Their Bacteriocins: Classification, Biosynthesis and Applications against Uropathogens: A Mini-Review

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    Mduduzi Paul Mokoena

    2017-07-01

    Full Text Available Several lactic acid bacteria (LAB isolates from the Lactobacillus genera have been applied in food preservation, partly due to their antimicrobial properties. Their application in the control of human pathogens holds promise provided appropriate strains are scientifically chosen and a suitable mode of delivery is utilized. Urinary tract infection (UTI is a global problem, affecting mainly diabetic patients and women. Many uropathogens are developing resistance to commonly used antibiotics. There is a need for more research on the ability of LAB to inhibit uropathogens, with a view to apply them in clinical settings, while adhering to strict selection guidelines in the choice of candidate LAB. While several studies have indicated the ability of LAB to elicit inhibitory activities against uropathogens in vitro, more in vivo and clinical trials are essential to validate the efficacy of LAB in the treatment and prevention of UTI. The emerging applications of LAB such as in adjuvant therapy, oral vaccine development, and as purveyors of bioprotective agents, are relevant in infection prevention and amelioration. Therefore, this review explores the potential of LAB isolates and their bacteriocins to control uropathogens, with a view to limit clinical use of antibiotics.

  7. Properties of a Bacteriocin Produced by Bacillus subtilis EMD4 Isolated from Ganjang (Soy Sauce).

    Science.gov (United States)

    Liu, Xiaoming; Lee, Jae Yong; Jeong, Seon-Ju; Cho, Kye Man; Kim, Gyoung Min; Shin, Jung-Hye; Kim, Jong-Sang; Kim, Jeong Hwan

    2015-09-01

    A Bacillus species, EMD4, with strong antibacterial activity was isolated from ganjang (soy sauce) and identified as B. subtilis. B. subtilis EMD4 strongly inhibited the growth of B. cereus ATCC14579 and B. thuringiensis ATCC33679. The antibacterial activity was stable at pH 3-9 but inactive at pH 10 and above. The activity was fully retained after 15 min at 80°C but reduced by 50% after 15 min at 90°C. The activity was completely destroyed by proteinase K and protease treatment, indicating its proteinaceous nature. The bacteriocin (BacEMD4) was partially purified from culture supernatant by ammonium sulfate precipitation, and QSepharose and Sephadex G-50 column chromatographies. The specific activity was increased from 769.2 AU/mg protein to 8,347.8 AU/mg protein and the final yield was 12.6%. The size of BacEMD4 was determined to be 3.5 kDa by Tricine SDS-PAGE. The N-terminal amino acid sequence was similar with that of Subtilosin A. Nucleotide sequencing of the cloned gene confirmed that BacEMD4 was Subtilosin A. BacEMD4 showed bactericidal activity against B. cereus ATCC14579.

  8. Anti-bacterial Efficacy of Bacteriocin Produced by Marine Bacillus subtilis Against Clinically Important Extended Spectrum Beta-Lactamase Strains and Methicillin-Resistant Staphylococcus aureus

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    Suresh Mickymaray

    2018-02-01

    Full Text Available Objective: To investigate the anti-bacterial efficacy of bacteriocin produced by Bacillus subtilis SM01 (GenBank accession no: KY612347, a Gram-positive marine bacterium, against Extended Spectrum Beta-Lactamase (ESBL producing Gram-negative pathogens Acinetobacter baumannii, Pseudomonas aeruginosa, and Escherichia coli, and Gram-positive pathogen Methicillin-Resistant Staphylococcus aureus (MRSA. Methods: A marine bacterium was isolated from mangrove sediment from the Red Sea coast of Jeddah, Kingdom of Saudi Arabia, and identified based on its morphological, biochemical, and molecular characteristics. The bacteriocin production using this isolate was carried out in brain heart infusion broth (BHIB medium. The Anti-bacterial activity of bacteriocin was evaluated against selected ESBL strains and MRSA by the well agar method. The effects of incubation time, pH, and temperature on the Anti-bacterial activity were studied. Results: The bacteriocin Bac-SM01 produced by B. subtilis SM01 demonstrated broad-spectrum Anti-bacterial activity against both Gram-negative and -positive bacteria. The present study is the first report that the bacteriocin Bac-SM01 inhibits the growth of ESBL producing Gram-negative strains A. baumannii, P. aeruginosa, and E. coli, and a Gram-positive MRSA strain. The optimum incubation time, pH, and temperature for the Anti-bacterial activity of Bac-SM01 was 24 h, 7, and 37°C respectively. Conclusion: The overall investigation can conclude that the bacteriocin Bac-SM01 from the marine isolate Bacillus subtilis SM01 could be used as an alternative Anti-bacterial agent in pharmaceutical products.

  9. Release of Bacteriocins from Nanofibers Prepared with Combinations of Poly(D,L-lactide (PDLLA and Poly(Ethylene Oxide (PEO

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    Leon Dicks

    2011-03-01

    Full Text Available Plantaricin 423, produced by Lactobacillus plantarum, and bacteriocin ST4SA produced by Enterococcus mundtii, were electrospun into nanofibers prepared from different combinations of poly(D,L-lactide (PDLLA and poly(ethylene oxide (PEO dissolved in N,N-dimethylformamide (DMF. Both peptides were released from the nanofibers with a high initial burst and retained 88% of their original antimicrobial activity at 37 °C. Nanofibers have the potential to serve as carrier matrix for bacteriocins and open a new field in developing controlled antimicrobial delivery systems for various applications.

  10. Cloning strategies for heterologous expression of the bacteriocin enterocin A by Lactobacillus sakei Lb790, Lb. plantarum NC8 and Lb. casei CECT475.

    Science.gov (United States)

    Jiménez, Juan J; Diep, Dzung B; Borrero, Juan; Gútiez, Loreto; Arbulu, Sara; Nes, Ingolf F; Herranz, Carmen; Cintas, Luis M; Hernández, Pablo E

    2015-10-15

    Bacteriocins produced by lactic acid bacteria (LAB) attract considerable interest as natural and nontoxic food preservatives and as therapeutics whereas the bacteriocin-producing LAB are considered potential probiotics for food, human and veterinary applications, and in the animal production field. Within LAB the lactobacilli are increasingly used as starter cultures for food preservation and as probiotics. The lactobacilli are also natural inhabitants of the gastrointestinal (GI) tract and attractive vectors for delivery of therapeutic peptides and proteins, and for production of bioactive peptides. Research efforts for production of bacteriocins in heterologous hosts should be performed if the use of bacteriocins and the LAB bacteriocin-producers is ever to meet the high expectations deposited in these antimicrobial peptides. The recombinant production and functional expression of bacteriocins by lactobacilli would have an additive effect on their probiotic functionality. The heterologous production of the bacteriocin enterocin A (EntA) was evaluated in different Lactobacillus spp. after fusion of the versatile Sec-dependent signal peptide (SP usp45 ) to mature EntA plus the EntA immunity gene (entA + entiA) (fragment UAI), and their cloning into plasmid vectors that permitted their inducible (pSIP409 and pSIP411) or constitutive (pMG36c) production. The amount, antimicrobial activity (AA) and specific antimicrobial activity (SAA) of the EntA produced by Lactobacillus sakei Lb790, Lb. plantarum NC8 and Lb. casei CECT475 transformed with the recombinant plasmids pSIP409UAI, pSIP411UAI and pMGUAI varied depending of the expression vector and the host strain. The Lb. casei CECT475 recombinant strains produced the largest amounts of EntA, with the highest AA and SAA. Supernatants from Lb. casei CECT (pSIP411UAI) showed a 4.9-fold higher production of EntA with a 22.8-fold higher AA and 4.7-fold higher SAA than those from Enterococcus faecium T136, the natural

  11. Antimicrobial activity and partial characterization of bacteriocin-like inhibitory substances produced by Lactobacillus spp. isolated from artisanal Mexican cheese.

    Science.gov (United States)

    Heredia-Castro, Priscilia Y; Méndez-Romero, José I; Hernández-Mendoza, Adrián; Acedo-Félix, Evelia; González-Córdova, Aarón F; Vallejo-Cordoba, Belinda

    2015-12-01

    Lactobacillus spp. from Mexican Cocido cheese were shown to produce bacteriocin-like substances (BLS) active against Staphylococcus aureus,Listeria innocua,Escherichia coli, andSalmonella typhimurium by using the disk diffusion method. Crude extracts of Lactobacillus fermentum showed strong inhibitory activity against Staph. aureus, L. innocua, E. coli, and Salmonella cholerae. Complete inactivation of antimicrobial activity was observed after treatment of crude extracts with proteinase K, pronase, papain, trypsin, and lysozyme, confirming their proteinaceous nature. However, antimicrobial activity was partly lost for some of the crude extracts when treated with α-amylase, indicating that carbohydrate moieties were involved. The antimicrobial activity of the crude extracts was stable at 65°C for 30min over a wide pH range (2-8), and addition of potassium chloride, sodium citrate, ethanol, and butanol did not affect antibacterial activity. However, antimicrobial activity was lost after heating at 121°C for 15min, addition of methanol or Tween 80. Fourteen out of 18 Lactobacillus spp. showed antimicrobial activity against different test microorganisms, and 12 presented bacteriocin-like substances. Generation time and growth rate parameters indicated that the antimicrobial activity of crude extracts from 3 different strains was effective against the 4 indicator microorganisms. One of the crude extracts showed inhibition not only against gram-positive but also against gram-negative bacteria. Bacteriocin-like substances produced by this specific Lactobacillus strain showed potential for application as a food biopreservative. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  12. Isolation and characterization of large spectrum and multiple bacteriocin-producing Enterococcus faecium strain from raw bovine milk.

    Science.gov (United States)

    Gaaloul, N; ben Braiek, O; Hani, K; Volski, A; Chikindas, M L; Ghrairi, T

    2015-02-01

    To assess the antimicrobial properties of lactic acid bacteria from Tunisian raw bovine milk. A bacteriocin-producing Enterococcus faecium strain was isolated from raw cow milk with activity against Gram-positive and Gram-negative bacteria. Antimicrobial substances produced by this strain were sensitive to proteolytic enzymes and were thermostable and resistant to a broad range of pH (2-10). Mode of action of antimicrobial substances was determined as bactericidal. Maximum activity was reached at the end of the exponential growth phase when checked against Listeria ivanovii BUG 496 (2366.62 AU ml(-1)). However, maximum antimicrobial activity against Pseudomonas aeruginosa 28753 was recorded at the beginning of the exponential growth phase. Enterococcus faecium GGN7 was characterized as free from virulence factors and was susceptible to tested antibiotics. PCR analysis of the micro-organism's genome revealed the presence of genes coding for enterocins A and B. Mass spectrometry analysis of RP-HPLC active fractions showed molecular masses corresponding to enterocins A (4835.77 Da) and B (5471.56 Da), and a peptide with a molecular mass of 3215.5 Da active only against Gram-negative indicator strains. The latter was unique in the databases. Enterococcus faecium GGN7 produces three bacteriocins with different inhibitory spectra. Based on its antimicrobial properties and safety, Ent. faecium GGN7 is potentially useful for food biopreservation. The results suggest the bacteriocins from GGN7 strain could be useful for food biopreservation. © 2014 The Society for Applied Microbiology.

  13. Purification and characterization of bacteriocin like substance produced from bacillus lentus with perspective of a new biopreservative for food preservation

    International Nuclear Information System (INIS)

    Sharma, N.; Gautam, N.

    2009-01-01

    Molecular weight of bacteriocin like substance (BLIS) of a new strain of Bacillus lentus 121 was found to be approximately 11 kDa. Purification of BLIS was attained by single step gel exclusion chromatography. BLIS was characterized by studying the inhibitory spectrum. It was active at broad pH range, high temperature and high NaCl concentration and showed sensitivity to proteolytic enzymes like trypsin, alpha-chymotrypsin and papain, the characters desirable for food preservation. BLIS extended the shelf stability of milk upto 21 days as a biopreservative. (author)

  14. Inhibition of Cronobacter sakazakii by heat labile bacteriocins produced by probiotic LAB isolated from healthy infants.

    Science.gov (United States)

    Awaisheh, Saddam S; Al-Nabulsi, Anas A; Osaili, Tareq M; Ibrahim, Salam; Holley, Richard

    2013-09-01

    Cronobacter sakazakii is an opportunistic pathogen that can cause bacteremia, meningitis, and necrotizing enterocolitis, most often in neonates with case-fatality rates that may reach 80%. The antimicrobial activity of lactic acid bacteria against a wide range of foodborne pathogens is well-established in different types of food products. The objective of the current study was to investigate the antibacterial activity of Lactobacillus acidophilus and L. casei isolated from feces of healthy infants against different strains of C. sakazakii in agar and a rehydrated infant milk formula (RIMF) model. The inhibition zones of C. sakazakii around L. acidophilus or L. casei ranged from 22 to 32 mm on eMan Rogosa Sharpe (MRS) agar under aerobic conditions, while a slight reduction in antibacterial activity was noted on modified MRS (0.2% glucose) under anaerobic conditions. It was observed that pH-neutralized cell-free supernatant (CFS) of L. acidophilus or L. casei was inhibitory against tested C. sakazakii strains. The inhibition zones of neutralized CFS were lower than the antibacterial activities of live cultures. The antibacterial activity of CFS was abolished when CFS from L. acidophilus or L. casei was heated at 60 or 80 °C for either 10 min or 2 h, or treated with trypsin or pepsin. This was considered strong evidence that the inhibition was due to the production of bacteriocins by L. casei and L. acidophilus. Both the CFS and active growing cells of L. casei and L. acidophilus were able to reduce the viability of C. sakazakii in the RIMF model. The results may extend the use of natural antimicrobials instead of conventional preservation methods to improve the safety of RIMF. © 2013 Institute of Food Technologists®

  15. Regulation of toxin and bacteriocin gene expression in Clostridium by interchangeable RNA polymerase sigma factors.

    Science.gov (United States)

    Dupuy, Bruno; Raffestin, Stéphanie; Matamouros, Susana; Mani, Nagraj; Popoff, Michel R; Sonenshein, Abraham L

    2006-05-01

    The production of major extracellular toxins by pathogenic strains of Clostridium botulinum, Clostridium tetani and Clostridium difficile, and a bacteriocin by Clostridium perfringens is dependent on a related group of RNA polymerase sigma-factors. These sigma-factors (BotR, TetR, TcdR and UviA) were shown to be sufficiently similar that they could substitute for one another in in vitro DNA binding and run-off transcription experiments. In cells, however, the sigma-factors fell into two subclasses. BotR and TetR were able to direct transcription of their target genes in a fully reciprocal manner. Similarly, UviA and TcdR were fully interchangeable. Neither BotR nor TetR could substitute for UviA or TcdR, however, and neither UviA nor TcdR could direct transcription of the natural targets of BotR or TetR. The extent of functional interchangeability of the sigma-factors was attributed to the strong conservation of their subregion 4.2 sequences and the conserved -35 sequences of their target promoters, while restrictions on interchangeability were attributed to variations in their subregion 2.4 sequences and the target site -10 sequences. The four sigma-factors have been assigned to group 5 of the sigma(70) family and seem to have arisen from a common ancestral protein that may have co-evolved with the genes whose transcription they direct. A fifth Clostridiumsigma-factor, sigma(Y) of Clostridium acetobutylicum, resembles the TcdR family, but was not functionally interchangeable with members of this family.

  16. R-type bacteriocins in related strains of Xenorhabdus bovienii: Xenorhabdicin tail fiber modularity and contribution to competitiveness.

    Science.gov (United States)

    Ciezki, Kristin; Murfin, Kristen; Goodrich-Blair, Heidi; Stock, S Patricia; Forst, Steven

    2017-01-01

    R-type bacteriocins are contractile phage tail-like structures that are bactericidal towards related bacterial species. The C-terminal region of the phage tail fiber protein determines target-binding specificity. The mutualistic bacteria Xenorhabdus nematophila and X. bovienii produce R-type bacteriocins (xenorhabdicins) that are selectively active against different Xenorhabdus species. We analyzed the P2-type remnant prophage clusters in draft sequences of nine strains of X. bovienii The C-terminal tail fiber region in each of the respective strains was unique and consisted of mosaics of modular units. The region between the main tail fiber gene (xbpH1) and the sheath gene (xbpS1) contained a variable number of modules encoding tail fiber fragments. DNA inversion and module exchange between strains was involved in generating tail fiber diversity. Xenorhabdicin-enriched fractions from three different X. bovienii strains isolated from the same nematode species displayed distinct activities against each other. In one set of strains, the strain that produced highly active xenorhabdicin was able to eliminate a sensitive strain. In contrast, xenorhabdicin activity was not a determining factor in the competitive fitness of a second set of strains. These findings suggest that related strains of X. bovienii use xenorhabdicin and additional antagonistic molecules to compete against each other. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. An isolate of Haemophilus haemolyticus produces a bacteriocin-like substance that inhibits the growth of nontypeable Haemophilus influenzae.

    Science.gov (United States)

    Latham, Roger D; Gell, David A; Fairbairn, Rory L; Lyons, A Bruce; Shukla, Shakti D; Cho, Kum Yin; Jones, David A; Harkness, Nick M; Tristram, Stephen G

    2017-04-01

    Nontypeable Haemophilus influenzae (NTHi) frequently colonises the upper respiratory tract and is an important cause of respiratory infections. Resistance to antibiotics is an emerging trend in NTHi and alternative prevention or treatment strategies are required. Haemophilus haemolyticus is a common commensal occupying the same niche as NTHi and, if able to produce substances that inhibit NTHi growth, may have a role as a probiotic. In this study, ammonium sulphate extracts from broth culture of 100 H. haemolyticus isolates were tested for the presence of substances inhibitory to NTHi using a well diffusion assay. One isolate produced a substance that consistently inhibited the growth of NTHi. The substance was inactivated by protease enzymes and had a molecular size of ca. 30 kDa as determined by size exclusion chromatography. When the substance was tested against bacteria from eight Gram-negative and three Gram-positive genera, only Haemophilus spp. were inhibited. Quantitative PCR testing showed the substance to be different to 'haemocin', the previously described bacteriocin of H. influenzae type b. These molecular characteristics, together with narrow-spectrum activity, suggest the substance may be a novel bacteriocin, and there is potential for this H. haemolyticus isolate to function as a probiotic for reduction of colonisation and subsequent infection with NTHi. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  18. Thermally triggered release of the bacteriophage endolysin CHAPKand the bacteriocin lysostaphin for the control of methicillin resistant Staphylococcus aureus (MRSA).

    Science.gov (United States)

    Hathaway, Hollie; Ajuebor, Jude; Stephens, Liam; Coffey, Aidan; Potter, Ursula; Sutton, J Mark; Jenkins, A Toby A

    2017-01-10

    Staphylococcus aureus infections of the skin and soft tissue pose a major concern to public health, largely owing to the steadily increasing prevalence of drug resistant isolates. As an alternative mode of treatment both bacteriophage endolysins and bacteriocins have been shown to possess antimicrobial efficacy against multiple species of bacteria including otherwise drug resistant strains. Despite this, the administration and exposure of such antimicrobials should be restricted until required in order to discourage the continued evolution of bacterial resistance, whilst maintaining the activity and stability of such proteinaceous structures. Utilising the increase in skin temperature during infection, the truncated bacteriophage endolysin CHAP K and the staphylococcal bacteriocin lysostaphin have been co-administered in a thermally triggered manner from Poly(N-isopropylacrylamide) (PNIPAM) nanoparticles. The thermoresponsive nature of the PNIPAM polymer has been employed in order to achieve the controlled expulsion of a synergistic enzybiotic cocktail consisting of CHAP K and lysostaphin. The point at which this occurs is modifiable, in this case corresponding to the threshold temperature associated with an infected wound. Consequently, bacterial lysis was observed at 37°C, whilst growth was maintained at the uninfected skin temperature of 32°C. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  19. Identification of a two-component Class IIb bacteriocin in Streptococcus pyogenes by recombinase-based in vivo expression technology

    Science.gov (United States)

    Armstrong, Brent D.; Herfst, Christine A.; Tonial, Nicholas C.; Wakabayashi, Adrienne T.; Zeppa, Joseph J.; McCormick, John K.

    2016-01-01

    Streptococcus pyogenes is a globally prominent bacterial pathogen that exhibits strict tropism for the human host, yet bacterial factors responsible for the ability of S. pyogenes to compete within this limited biological niche are not well understood. Using an engineered recombinase-based in vivo expression technology (RIVET) system, we identified an in vivo-induced promoter region upstream of a predicted Class IIb bacteriocin system in the M18 serotype S. pyogenes strain MGAS8232. This promoter element was not active under in vitro laboratory conditions, but was highly induced within the mouse nasopharynx. Recombinant expression of the predicted mature S. pyogenes bacteriocin peptides (designated SpbM and SpbN) revealed that both peptides were required for antimicrobial activity. Using a gain of function experiment in Lactococcus lactis, we further demonstrated S. pyogenes immunity function is encoded downstream of spbN. These data highlight the importance of bacterial gene regulation within appropriate environments to help understand mechanisms of niche adaptation by bacterial pathogens. PMID:27808235

  20. Description of two Enterococcus strains isolated from traditional Peruvian artisanal-produced cheeses with a bacteriocin-like inhibitory activity

    Directory of Open Access Journals (Sweden)

    Aguilar Galvez A.

    2009-01-01

    Full Text Available The aim of this work was to isolate and to characterize strains of lactic acid bacteria (LAB with bacteriocin-like inhibitory activity from 27 traditional cheeses artisanal-produced obtained from different Peruvian regions. Twenty Gram+ and catalasenegative strains among 2,277 isolates exhibited bacteriocin-like inhibitory activity against Listeria monocytogenes CWBIB2232 as target strain. No change in inhibitory activity was observed after organic acid neutralization and treatment with catalase of the cell-free supernatant (CFS. The proteinic nature of the antimicrobial activity was confirmed for the twenty LAB strains by proteolytic digestion of the CFS. Two strains, CWBI-B1431 and CWBI-B1430, with the best antimicrobial activity were selected for further researches. These strains were taxonomically identified by phenotypic and genotypic analyses as Enterococcus mundtii (CWBI-B1431 and Enterococcus faecium (CWBI-B1430. The two strains were sensitive to vancomycin (MIC 2 μg.ml-1 and showed absence of haemolysis.

  1. Combined effect of bacteriocin-producing lactic acid bacteria and lactoperoxidase system activation on Listeria monocytogenes in refrigerated raw milk.

    Science.gov (United States)

    Rodríguez, E; Tomillo, J; Nuñez, M; Medina, M

    1997-09-01

    The bactericidal activity of three bacteriocin-producing lactic acid bacteria alone and in combination with milk lactoperoxidase (LP) system activation against Listeria monocytogenes in refrigerated raw milk was studied. After 4 d at 4 degrees C, the population of L. monocytogenes in milk inoculated with bacteriocin-producing Lactococcus lactis subsp. lactis ATCC 11454, L. lactis subsp. lactis ESI 515 or Enterococcus faecalis INIA 4 was reduced by 0.21-0.24 log units. Activation of the LP system did not enhance inhibition at this temperature. After 4 d at 8 degrees C, L. monocytogenes levels in the non-activated LP system milk inoculated with L. lactis subsp. lactis ATCC 11454, L. lactis subsp. lactis ESI 515 or Ent. faecalis INIA 4 were reduced by 1.87, 1.54 and 1.11 log units compared to control milk, whereas in the activated LP system milk, this reduction was 1.99, 2.10 and 1.06, respectively. The higher nisin production by L. lactis subsp. lactis ESI 515 in milk with activated LP system than in non-activated LP system milk was responsible for the more pronounced decrease of L. monocytogenes counts in the former.

  2. Characterization of a bacteriocin-like substance produced from a novel isolated strain of Bacillus subtilis SLYY-3

    Science.gov (United States)

    Li, Junfeng; Li, Hongfang; Zhang, Yuanyuan; Duan, Xiaohui; Liu, Jie

    2014-12-01

    In the present research, the strain SLYY-3 was isolated from sediments of Jiaozhou Bay, Qingdao, China. The strain SLYY-3, which produced a bacteriocin-like substance (BLS), was characterized to be a strain of Bacillus subtillis by biochemical profiling and 16S rDNA sequence analysis. It is the first time to report that Bacillus subtilis from Jiaozhou Bay sediments could produce a BLS. The BLS of B. subtillis SLYY-3 exhibited strong inhibitory activity against gram-positive bacteria (including Staphylococcus aureus and B. subtillis) and some fungi (including Penicillium glaucum, Aspergillus niger and Aspergillus flavus). The antimicrobial activity was detected from culture in the exponential growth phase and reached its maximum when culture entered into stationary growth phase. It was thermo-tolerant even when being kept at 100°C for 60 min without losing any activity and stable over a wide pH range from 1.0 to 12.0 while being inactivated by proteolytic enzyme and trypsin, indicating the proteinaceous nature of the BLS. The BLS was purified by precipitation with hydrochloric acid (HCl) and gel filteration (Sephadex G-100). SDS-PAGE analysis of the extracellular peptides of SLYY-3 revealed a bacteriocin-like protein with a molecular mass of 66 kDa. Altogether, these characteristics indicate the potential of the BLS for food industry as a protection against pathogenic and spoilage microorganisms.

  3. Inducer bacteria, unique signal peptides and low nutrient media stimulate in-vitro bacteriocin production by Lactobacillus spp. and Enterococcus spp. strains

    Science.gov (United States)

    Bacteriocins (BCN) provide promising potential to control bacterial infections in a variety of applications. We previously reported three Type IIa BCN produced by Lactobacillus salivarius B-30514 (OR-7), Enterococcus durans/faecium/hirae B-30745 (E 760) and Enterococcus faecium B-30746 (E 50-52). ...

  4. Molecular analysis of the bacteriocin-encoding plasmid pDGL1 from Enterococcus durans and genetic characterization of the durancin locus

    Science.gov (United States)

    Enterococci constitute a significant component of lactic acid bacteria normally present in the intestinal microflora and include strains that produce bacteriocins. The genetic determinants for durancin GL in Enterococcus durans 41D were identified on the 8,347 bp plasmid pDGL1 by plasmid curing exp...

  5. DNA analysis of the genes encoding acidocin LF221 A and acidocin LF221 B, two bacteriocins produced by Lactobacillus gasseri LF221

    NARCIS (Netherlands)

    Majhenič, A.Č.; Venema, K.; Allison, G.E.; Matijašić, B.B.; Rogelj, I.; Klaenhammer, T.R.

    2004-01-01

    Lactobacillus gasseri LF221, an isolate from the feces of a child, produces two bacteriocins. Standard procedures for molecular techniques were used to locate, clone and sequence the fragments of LF221 chromosomal DNA carrying the acidocin LF221 A and B structural genes, respectively. Sequencing

  6. Effects of curing sodium nitrite additive and natural meat fat on growth control of Listeria monocytogenes by the bacteriocin-producing Lactobacillus curvatus strain CWBI-B28.

    Science.gov (United States)

    Kouakou, P; Ghalfi, H; Destain, J; Dubois-Dauphin, R; Evrard, P; Thonart, P

    2009-09-01

    In realistic model meat systems, the separate and combined effects of fat content and sodium nitrite on the antilisterial activity of the bacteriocin of Lactobacillus curvatus CWBI-B28 were studied. In laboratory fermentations where Listeria monocytogenes was co-cultured at 4 degrees C with bacteriocin-producing CWBI-B28 in lean pork meat (fat content: 13%) without added nitrite, a strong antilisterial effect was observed after one week. The effect was maintained for an additional week, after which a slight and very gradual rebound was observed. Both added nitrite (20 ppm) and a high-fat content (43%) were found to antagonise this antilisterial effect, the Listeria cfu count reached after six weeks being 200 times as high in high-fat meat with added nitrite than in lean meat without nitrite. This antagonism could not be attributed to slower growth of the bacteriocin-producing strain, since CWBI-B28 grew optimally in fat-rich meat with 20 ppm sodium nitrite. Bacteriocin activity was also measured in the samples. The observed activity levels are discussed in relation to the degree of antilisterial protection conferred.

  7. In silico Prediction, in vitro Antibacterial Spectrum, and Physicochemical Properties of a Putative Bacteriocin Produced by Lactobacillus rhamnosus Strain L156.4

    Directory of Open Access Journals (Sweden)

    Letícia de C. Oliveira

    2017-05-01

    Full Text Available A bacteriocinogenic Lactobacillus rhamnosus L156.4 strain isolated from the feces of NIH mice was identified by 16S rRNA gene sequencing and MALDI-TOF mass spectrometry. The entire genome was sequenced using Illumina, annotated in the PGAAP, and RAST servers, and deposited. Conserved genes associated with bacteriocin synthesis were predicted using BAGEL3, leading to the identification of an open reading frame (ORF that shows homology with the L. rhamnosus GG (ATCC 53103 prebacteriocin gene. The encoded protein contains a conserved protein motif associated a structural gene of the Enterocin A superfamily. We found ORFs related to the prebacteriocin, immunity protein, ABC transporter proteins, and regulatory genes with 100% identity to those of L. rhamnosus HN001. In this study, we provide evidence of a putative bacteriocin produced by L. rhamnosus L156.4 that was further confirmed by in vitro assays. The antibacterial activity of the substances produced by this strain was evaluated using the deferred agar-spot and spot-on-the lawn assays, and a wide antimicrobial activity spectrum against human and foodborne pathogens was observed. The physicochemical characterization of the putative bacteriocin indicated that it was sensitive to proteolytic enzymes, heat stable and maintained its antibacterial activity in a pH ranging from 3 to 9. The activity against Lactobacillus fermentum, which was used as an indicator strain, was detected during bacterial logarithmic growth phase, and a positive correlation was confirmed between bacterial growth and production of the putative bacteriocin. After a partial purification from cell-free supernatant by salt precipitation, the putative bacteriocin migrated as a diffuse band of approximately 1.0–3.0 kDa by SDS-PAGE. Additional studies are being conducted to explore its use in the food industry for controlling bacterial growth and for probiotic applications.

  8. Optimization and biochemical characterization of a bacteriocin from a newly isolated Bacillus subtilis strain 14B for biocontrol of Agrobacterium spp. strains.

    Science.gov (United States)

    Hammami, I; Rhouma, A; Jaouadi, B; Rebai, A; Nesme, X

    2009-02-01

    The identification of a new compound active against Agrobacterium tumefaciens. The culture conditions of a newly isolated Bacillus subtilis strain, designed 14B, were optimized, as a first step, to produce its bacteriocin (termed Bac 14B) for the biocontrol of Agrobacterium spp., the causal agents of the crown gall disease. Bac 14B was then partially purified and biochemically characterized. Bacillus subtilis 14B was observed to produce an antibacterial compound having a protinaceous nature. As estimated by sodium dodecyl sulfate-polyacrilamide gel electrophoresis (SDS-PAGE), the semi-purified bacteriocin substance was found to be a monomeric protein with a molecular weight of 21 kDa. While the latter's antimicrobial activity was completely stable during exposure to a temperature range of up to 100 degrees C for 2 h, its initial activity was totally lost at 121 degrees C for 20 min. The maximum bacteriocin production (4096 AU ml(-1)) was recorded after 96 h-incubation in an optimized Luria Bertani medium supplemented with 10 g l(-1) glucose, 15 g l(-1) K(2)HPO(4) and 5 g l(-1) MgSO(4) 7H(2)O at 30 degrees C in a shaking flask culture. Interestingly, the B. subtilis 14B culture supernatant that contained the bacteriocin under study was proved efficient in reducing both the percentage of galled plants and the number of galls in tomato. The findings revealed that B. subtilis 14B and its bacteriocin are efficient in reducing the percentage of infections in plants caused by Ag. tumefaciens. The results could be useful for the nurserymen who are particularly interested in the biocontrol of the crown gall disease.

  9. Mathematical Model of Interaction Between Bacteriocin-Producing Lactic Acid Bacteria and Listeria. Part 2: Bifurcations and Applications.

    Science.gov (United States)

    Delboni, Roberta Regina; Yang, Hyun Mo

    2017-10-01

    The big challenge for the food industry is the attending to demands for minimally processed foods, avoiding intense heat treatments and reducing the addition of chemical preservatives, but at the same time ensuring microbiological safety of these products. Lactic acid bacteria are traditionally used in the production of fermented foods. They are responsible for the production of antimicrobial compounds, such as organic acids and bacteriocins, which are protein compounds with bactericidal effect against related species and bacteria such as Listeria monocytogenes and Staphylococcus aureus. Aiming to study quantitatively the biological control as a technique of conservation, we developed a mathematical model to describe the interaction between lactic acid bacteria and Listeria in the food. The steady state and dynamical trajectories analyses of the model permit us to study the suitability of including lactic acid bacteria in order to reduce the growth of Listeria in food.

  10. Regulation of toxin and bacteriocin synthesis in Clostridium species by a new subgroup of RNA polymerase sigma-factors.

    Science.gov (United States)

    Dupuy, Bruno; Matamouros, Susana

    2006-04-01

    Many Clostridium species are pathogenic for humans and animals, and most of the resulting diseases, such as tetanus, botulism, gas gangrene and pseudomembranous colitis, are due to the production of potent extracellular toxins. The biochemical mechanisms of action of Clostridium toxins have been extensively studied in the past ten years. However, detailed information about the regulation of toxin gene expression has only recently emerged. TcdR, BotR, TetR and UviA are now known to be related alternative RNA polymerase sigma factors that drive transcription of toxin A and toxin B genes in C. difficile, the neurotoxin genes in C. botulinum and C. tetani, and a bacteriocin gene in C. perfringens. Although the Clostridium sigma factors have some similarity to members of the ECF sigma factor group, they differ sufficiently in structure and function so that they have been assigned to a new group within the sigma(70)-family.

  11. Antibacterial activity and genotypic-phenotypic characteristics of bacteriocin-producing Bacillus subtilis KKU213: potential as a probiotic strain.

    Science.gov (United States)

    Khochamit, Nalisa; Siripornadulsil, Surasak; Sukon, Peerapol; Siripornadulsil, Wilailak

    2015-01-01

    The antimicrobial activity and probiotic properties of Bacillus subtilis strain KKU213, isolated from local soil, were investigated. The cell-free supernatant (CFS) of a KKU213 culture containing crude bacteriocins exhibited inhibitory effects on Gram-positive bacteria, including Bacillus cereus, Listeria monocytogenes, Micrococcus luteus, and Staphylococcus aureus. The antibacterial activity of the CFS precipitated with 40% ammonium sulfate (AS) remained even after treatment at 60 and 100 °C, at pH 4 and 10 and with proteolytic enzymes, detergents and heavy metals. When analyzed by SDS-PAGE and overlaid with the indicator strains B. cereus and S. aureus, the 40% AS precipitate exhibited inhibitory activity on proteins smaller than 10 kDa. However, proteins larger than 25 kDa and smaller than 10 kDa were still observed on a native protein gel. Purified subtilosin A was prepared by Amberlite XAD-16 bead extraction and HPLC and analyzed by Nano-LC-QTOF-MS. Its molecular mass was found to be 3.4 kDa, and it retained its antibacterial activity. These results are consistent with the detection of the anti-listerial subtilosin A gene of the sbo/alb cluster in the KKU213 strain, which is 100% identical to that of B. subtilis subsp. subtilis 168. In addition to stable and cyclic subtilosin A, a mixture of many extracellular antibacterial peptides was also detected in the KKU213 culture. The KKU213 strain produced extracellular amylase, cellulase, lipase and protease, is highly acid-resistant (pH 2) when cultured in inulin and promotes health and reduces infection of intestinally colonized broiler chickens. Therefore, we propose that bacteriocin-producing B. subtilis KKU213 could be used as a potential probiotic strain or protective culture. Copyright © 2014 Elsevier GmbH. All rights reserved.

  12. The effect of bacteriocin-producing Lactobacillus plantarum strains on the intracellular pH of sessile and planktonic Listeria monocytongenes single cells

    DEFF Research Database (Denmark)

    Nielsen, Dennis Sandris; Cho, Gyu-Sung; Hanak, Alexander

    2010-01-01

    and/or bacteriocin-producing LAB as “natural” food preservatives in foods such as cheese, meat and ready-to-eat products. Some strains of Lactobacillus plantarum produce bacteriocins termed plantaricins. Using a single-cell based approach, the effect on the intracellular pH as a measure...... unaffected after 5 h of co-culturing and after 8 h 50% of the cells still maintained pHi = 7. Higher concentrations of lactic acid were produced in liquid compared to a solid surface, and the different response of EGDe and N53-1 to the activities of the two L. plantarum strains probably reflect higher...... of the physiological state of sessile and planktonic L. monocytogenes (strains EGDe and N53-1) during co-culturing with plantaricin-producing L. plantarum (strains BFE 5092 and PCS 20) was investigated using fluorescence ratio imaging microscopy (FRIM). Mono-cultures of L. monocytogenes were used as control...

  13. Optimization of growth and bacteriocin activity of the food bioprotective Carnobacterium divergens V41 in an animal origin protein free medium

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    Anne BRILLET-VIEL

    2016-08-01

    Full Text Available Optimization of Carnobacterium divergens V41 growth and bacteriocin activity in a culture medium deprived of animal protein, needs for food bioprotection, was performed by using a statistical approach. In a screening experiment, twelve factors (pH, temperature, carbohydrates, NaCl, yeast extract, soy peptone, sodium acetate, ammonium citrate, magnesium sulphate, manganese sulphate, ascorbic acid and thiamine were tested for their influence on the maximal growth and bacteriocin activity using a two-level incomplete factorial design with 192 experiments performed in microtiter plate wells. Based on results, a basic medium was developed and three variables (pH, temperature and carbohydrates concentration were selected for a scale-up study in bioreactor. A 23 complete factorial design was performed, allowing the estimation of linear effects of factors and all the first order interactions. The best conditions for the cell production were obtained with a temperature of 15°C and a carbohydrates concentration of 20 g/l whatever the pH (in the range 6.5-8, and the best conditions for bacteriocin activity were obtained at 15°C and pH 6.5 whatever the carbohydrates concentration (in the range 2-20 g/l. The predicted final count of C. divergens V41 and the bacteriocin activity under the optimized conditions (15°C, pH 6.5, 20 g/l carbohydrates were 2.4 x 1010 CFU/ml and 819200 AU/ml respectively. C. divergens V41 cells cultivated in the optimized conditions were able to grow in cold-smoked salmon and totally inhibited the growth of Listeria monocytogenes (< 50 CFU g-1 during five weeks of vacuum storage at 4° and 8°C.

  14. Lytic activity of LysH5 endolysin secreted by Lactococcus lactis using the secretion signal sequence of bacteriocin Lcn972.

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    Rodríguez-Rubio, Lorena; Gutiérrez, Dolores; Martínez, Beatriz; Rodríguez, Ana; García, Pilar

    2012-05-01

    Bacteriophage endolysins have an interesting potential as antimicrobials. The endolysin LysH5, encoded by Staphylococcus aureus phage vB_SauS-phi-IPLA88, was expressed and secreted in Lactococcus lactis using the signal peptide of bacteriocin lactococcin 972 and lactococcal constitutive and inducible promoters. Up to 80 U/mg of extracellular active endolysin was detected in culture supernatants, but most of the protein (up to 323 U/mg) remained in the cell extracts.

  15. 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.

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    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.

  16. A successful use of a new shuttle cloning vector pA13 for the cloning of the bacteriocins BacSJ and acidocin 8912

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    Kojić Milan

    2010-01-01

    Full Text Available The aim of this paper was to research the molecular cloning of genes encoding the novel bacteriocin BacSJ from Lactobacillus paracasei subsp. paracasei BGSJ2-8 by using a newly constructed shuttle cloning vector pA13. A new shuttle-cloning vector, pA13, was constructed and successfully introduced into Escherichia coli, Lactobacillus and Lactococcus strains, showing a high segregational and structural stability in all three hosts. The natural plasmid pSJ2-8 from L. paracasei subsp. paracasei BGSJ2-8 was cloned in the pA13 using BamHI, obtaining the construct pB5. Sequencing and in silico analysis of the pB5 revealed 15 open reading frames (ORF. Plasmid pSJ2-8 harbors the genes encoding the production of two bacteriocins, BacSJ and acidocin 8912. The combined N-terminal amino acid sequencing of BacSJ in combination with DNA sequencing of the bacSJ2-8 gene enabled the determination of the primary structure of a bacteriocin BacSJ. The production and functional expression of BacSJ in homologous and heterologous hosts suggest that bacSJ2-8 and bacSJ2-8i together with the genes encoding the ABC transporter and accessory protein are the minimal requirement for the production of BacSJ. Biochemical and genetic analyses showed that BacSJ belongs to the class II bacteriocins. The shuttle cloning vector pA13 could be used as a tool for genetic manipulations in lactobacilli and lactococci.

  17. Pentocin MQ1: A Novel, Broad-Spectrum, Pore-Forming Bacteriocin From Lactobacillus pentosus CS2 With Quorum Sensing Regulatory Mechanism and Biopreservative Potential

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    Samson B. Wayah

    2018-03-01

    Full Text Available Micrococcus luteus, Listeria monocytogenes, and Bacillus cereus are major food-borne pathogenic and spoilage bacteria. Emergence of antibiotic resistance and consumer demand for foods containing less of chemical preservatives led to a search for natural antimicrobials. A study aimed at characterizing, investigating the mechanism of action and regulation of biosynthesis and evaluating the biopreservative potential of pentocin from Lactobacillus pentosus CS2 was conducted. Pentocin MQ1 is a novel bacteriocin isolated from L. pentosus CS2 of coconut shake origin. The purification strategy involved adsorption-desorption of bacteriocin followed by RP-HPLC. It has a molecular weight of 2110.672 Da as determined by MALDI-TOF mass spectrometry and a molar extinction value of 298.82 M−1 cm−1. Pentocin MQ1 is not plasmid-borne and its biosynthesis is regulated by a quorum sensing mechanism. It has a broad spectrum of antibacterial activity, exhibited high chemical, thermal and pH stability but proved sensitive to proteolytic enzymes. It is potent against M. luteus, B. cereus, and L. monocytogenes at micromolar concentrations. It is quick-acting and exhibited a bactericidal mode of action against its targets. Target killing was mediated by pore formation. We report for the first time membrane permeabilization as a mechanism of action of the pentocin from the study against Gram-positive bacteria. Pentocin MQ1 is a cell wall-associated bacteriocin. Application of pentocin MQ1 improved the microbiological quality and extended the shelf life of fresh banana. This is the first report on the biopreservation of banana using bacteriocin. These findings place pentocin MQ1 as a potential biopreservative for further evaluation in food and medical applications.

  18. A Sequential Statistical Approach towards an Optimized Production of a Broad Spectrum Bacteriocin Substance from a Soil Bacterium Bacillus sp. YAS 1 Strain

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    Amira M. Embaby

    2014-01-01

    Full Text Available Bacteriocins, ribosomally synthesized antimicrobial peptides, display potential applications in agriculture, medicine, and industry. The present study highlights integral statistical optimization and partial characterization of a bacteriocin substance from a soil bacterium taxonomically affiliated as Bacillus sp. YAS 1 after biochemical and molecular identifications. A sequential statistical approach (Plackett-Burman and Box-Behnken was employed to optimize bacteriocin (BAC YAS 1 production. Using optimal levels of three key determinants (yeast extract (0.48% (w/v, incubation time (62 hrs, and agitation speed (207 rpm in peptone yeast beef based production medium resulted in 1.6-fold enhancement in BAC YAS 1 level (470 AU/mL arbitrary units against Erwinia amylovora. BAC YAS 1 showed activity over a wide range of pH (1–13 and temperature (45–80°C. A wide spectrum antimicrobial activity of BAC YAS 1 against the human pathogens (Clostridium perfringens, Staphylococcus epidermidis, Campylobacter jejuni, Enterobacter aerogenes, Enterococcus sp., Proteus sp., Klebsiella sp., and Salmonella typhimurium, the plant pathogen (E. amylovora, and the food spoiler (Listeria innocua was demonstrated. On top and above, BAC YAS 1 showed no antimicrobial activity towards lactic acid bacteria (Lactobacillus bulgaricus, L. casei, L. lactis, and L. reuteri. Promising characteristics of BAC YAS 1 prompt its commercialization for efficient utilization in several industries.

  19. Effect of liposome-encapsulated nisin and bacteriocin-like substance P34 on Listeria monocytogenes growth in Minas frescal cheese.

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    Malheiros, Patrícia da Silva; Sant'Anna, Voltaire; Barbosa, Matheus de Souza; Brandelli, Adriano; Franco, Bernadette Dora Gombossy de Melo

    2012-06-01

    The efficacy of liposome-encapsulated nisin and bacteriocin-like substance (BLS) P34 to control growth of Listeria monocytogenes in Minas frescal cheese was investigated. Nisin and BLS P34 were encapsulated in partially purified soybean phosphatidylcholine (PC-1) and PC-1-cholesterol (7:3) liposomes. PC-1 nanovesicles were previously characterized. PC-1-cholesterol encapsulated nisin and BLS P34 presented, respectively, 218 nm and 158 nm diameters, zeta potential of -64 mV and -53 mV, and entrapment efficiency of 88.9% and 100%. All treatments reduced the population of L. monocytogenes compared to the control during 21 days of storage of Minas frescal cheese at 7°C. However, nisin and BLS P34 encapsulated in PC-1-cholesterol liposomes were less efficient in controlling L. monocytogenes growth in comparison with free and PC-1 liposome-encapsulated bacteriocins. The highest inhibitory effect was observed for nisin and BLS P34 encapsulated in PC-1 liposomes after 10 days of storage of the product. The encapsulation of bacteriocins in liposomes of partially purified soybean phosphatidylcholine may be a promising technology for the control of foodborne pathogens in cheeses. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Antibacterial and Synergistic Activity Against β-Lactamase-Producing Nosocomial Bacteria by Bacteriocin of LAB Isolated From Lesser Known Traditionally Fermented Products of India

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    Koel Biswas

    2017-04-01

    Full Text Available There is an ever-growing need to control antibiotic-resistance owing to alarming resistance to commonly available antimicrobial agents for which contemporary and alternative approaches are being explored. The present study assessed the antibacterial activity of bacteriocins from lactic acid bacteria (LAB from lesser known traditionally fermented products of India for their synergistic potential with common antibiotics against clinical β-lactamases producing pathogens. A total of 84 isolates of LAB were screened for their antibacterial efficacy against Streptococcus pyogenes, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae and Bacillus cereus as well as against clinical pathogens harbouring β-lactamase genes such as blaCTX-M, blaVIM, blaIMP, blaSHV and blaNDM. Synergistic activity of bacteriocins were determined in combination with antibiotics namely, cefotaxime, polymyxin B, imipenem and tigecycline. Purified bacteriocins from Lactobacillus, Pediococcus and Enterococcus inhibited the growth of β-lactamase harbouring clinical pathogens which significantly higher inhibitions when compared with antibiotics alone. Minimum inhibitory concentration of the extracts ranged from 6.66 to 26.66 mg/ml and 10 to 33.33 mg/ml for Pediococcus pentosaceus LU11 and Lactobacillus plantarum LS6. The bacteriocinogenic activity of LAB opens scope for bioprospection of antibacterial components in the current struggle against increasing pandrug resistance and slowing down the expansion of multi-drug resistance.

  1. Purification, Characterization, and Mode of Action of Pentocin JL-1, a Novel Bacteriocin Isolated from Lactobacillus pentosus, against Drug-Resistant Staphylococcus aureus

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    Han Jiang

    2017-01-01

    Full Text Available Staphylococcus aureus and its drug-resistant strains, which threaten public health and food safety, are in need of effective control by biopreservatives. A novel bacteriocin, pentocin JL-1, produced by Lactobacillus pentosus that was isolated from the intestinal tract of Chiloscyllium punctatum, was purified by a four-step chromatographic process. Mass spectrometry based on MALDI-TOF indicated that pentocin JL-1 has a molecular mass of 2987.23 Da. Only six of the twenty-five amino acids could be identified by Edman degradation. This bacteriocin is thermostable and tolerates a pH range of 5–7. Also, it is sensitive to proteinase K, trypsin, pepsin, and alkaline protease. This bacteriocin has a broad inhibitory spectrum against both Gram-positive and Gram-negative strains and in particular is effective against multidrug-resistant S. aureus. Additionally, we showed that the cell membrane is the target of pentocin JL-1 against methicillin-resistant S. aureus (MRSA, causing a loss of proton motive force. Furthermore, pentocin JL-1 has a drastic impact on the structure and integrity of MRSA cells. These results suggest that pentocin JL-1 has potential as a biopreservative in the food industry.

  2. Identification and partial characterization of a bacteriocin-like inhibitory substance (BLIS) from Lb. Bulgaricus K41 isolated from indigenous yogurts.

    Science.gov (United States)

    Zaeim, Davood; Soleimanian-Zad, Sabihe; Sheikh-Zeinoddin, Mahmoud

    2014-01-01

    Forty-two strains of Lactobacillus bulgaricus isolated from locally made yogurts were examined and compared for bacteriocin producing ability using spot on lawn assay which improved by taking photo and image processing. Lb. bulgaricus K41 exhibited the highest inhibition level against indicators. K41 Bacteriocin-like inhibitory substance is sensitive to proteolytic enzymes (proteinase K, pepsin, and trypsin) but α-amylase makes slight reduction in its activity and it is resistant to lipase. This antibacterial peptide is extremely heat-stable (121 °C for 15 min) and remains active over a wide pH range (pH = 2 to 10); also nonionic detergents (Tween-20, Tween-80, and Triton X100) showed no effect on its activity. The inhibitory spectrum is against Gram-positive bacteria (except Staphylococcus aureus) with extremely antilisterial activity and it is almost ineffective against Gram-negative bacteria. The mode of its action was identified as bactericidal against Listeria monocytogenes. The properties of K41 bacteriocin-like inhibitory substance add to its safety as a biopreservative produced by a generally recognized as safe (GRAS) bacterium suggesting it can be used in hurdle technology for ready-to-eat foods as one of the main sources of Listeria contaminations. © 2013 Institute of Food Technologists®

  3. Mutacins and bacteriocins like genes in Streptococcus mutans isolated from participants with high, moderate, and low salivary count.

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    Soto, Carolina; Padilla, Carlos; Lobos, Olga

    2017-02-01

    To detect S. mutans producers of mutacins and bacteriocins like substances (BLIS) from saliva of participants with low, moderate, and high salivary counts. 123 strains of S. mutans were obtained from participants with low, moderate, and high salivary counts (age 18 and 20 years old) and their antibacterial capacity analyzed. By using PCR amplification, the expression levels of mutacins and BLIS genes were studied (expressed in arbitrary units/ml) in all three levels. S. mutans strains from participants with low salivary counts show high production of mutacins (63%). In contrast, participants with moderate and high salivary counts depict relatively low levels of mutacins (22 and 15%, respectively). Moreover, participants with low salivary counts showed high expression levels of genes encoding mutacins, a result that correlates with the strong antimicrobial activity of the group. Participants with moderate and high salivary counts however depict low expression levels of mutacin related genes, and little antimicrobial activity. No BLIS were detected in any of the groups studied. S. mutans isolated from the saliva of participants with low bacterial counts have significant antibacterial capacity compared to that of participants with moderate and high salivary counts. The superior lethality of S. mutans in participants with low salivary counts is likely due to the augmented expression of mutacin- related genes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Preservation of large yellow croaker (Pseudosciaena crocea) by Coagulin L1208, a novel bacteriocin produced by Bacillus coagulans L1208.

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    Fu, Linglin; Wang, Chong; Ruan, Xinming; Li, Gang; Zhao, Yu; Wang, Yanbo

    2018-02-02

    Large yellow croaker (Pseudosciaena crocea) is a cultivated fish of great economic importance and abundant nutritional value. However, due to its high protein and water contents, it is susceptible to decomposition, leading to considerable economic loss and adverse effects on consumer health. Here, we assessed the function of the bacterial strain Bacillus coagulans L1208 (Bcoa) in preserving large yellow croaker during storage at 4°C and found that Bcoa elongates the shelf-life significantly. Further investigations showed that Bcoa prolongs the storage time mainly by suppressing the growth of spoilage bacteria. Moreover, a novel bacteriocin, designated as Coagulin L1208 and produced by Bcoa, was purified and identified by N-terminal sequencing. Finally, the activity of Coagulin L1208 for suppressing spoilage bacteria during the preservation of large yellow croaker was assessed. Our results reveal the mechanism by which Bcoa aids the preservation of large yellow croaker and identify Coagulin L1208 as a potential novel antiseptic. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Characterisation of two novel bacteriocin-like substances produced by Bacillus amyloliquefaciens ELI149 with broad-spectrum antimicrobial activity.

    Science.gov (United States)

    Salazar, Francisco; Ortiz, Aurelio; Sansinenea, Estibaliz

    2017-12-01

    The aim of this study was to isolate and characterise antifungal and bactericidal compounds from Bacillus amyloliquefaciens strain ELI149. An absorbent resin (Amberlite ® XAD-16) and silica gel column chromatography were used for isolation and purification purposes, respectively. Antibacterial and antifungal assays were performed by the well diffusion method to demonstrate the biological activity of each compound. Cell damage of the tested fungi was evaluated for fengycin under phase-contrast microscopy. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and mass spectroscopy techniques were performed to estimate the approximate molecular mass of each compound. Two bacteriocin-like substances (BLSs) with different physical properties and inhibitory activities were isolated along with two known antifungal compounds. The two BLSs were heat stable and were not sensitive to acid or alkaline conditions (pH 2-10), with broad-spectrum antimicrobial activity. The antifungal compounds were identified as surfactin and fengycin. Only fengycin showed marked antifungal properties against several phytopathogens. The two isolated BLSs were partially characterised and their bactericidal properties were analysed. The antifungals compounds were identified as surfactin and fengycin, this latter being mainly responsible for the antifungal activity. Copyright © 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

  6. Detection and characterization of a bacteriocin, putadicin T01, produced by Pseudomonas putida isolated from hot spring water.

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    Ghrairi, Taoufik; Braiek, Olfa Ben; Hani, Khaled

    2015-03-01

    Pseudomonas strains isolated from hot spring water were tested for bacteriocin-like substance (BLS) production using a target panel of closely related microorganisms and other Gram-positive and Gram-negative bacteria. Molecular identification was carried out through specific PCR and 16S RNA sequence analysis. Isolates were identified as Brevundimonas diminuta and Pseudomonas putida, the latter exhibited antimicrobial activity. Pseudomonas putida strains produce an inhibitory substance against other Pseudomonas strains and other species including food-borne pathogens. The BLS was sensitive to the proteolytic action of proteinase K, pronase E and trypsin but resistant to α-amylase, RNase and lipase C, reflecting its proteinaceous nature. The BLS was stable at 100 °C and also after thermal treatment at 121 °C for 15 min. Additionally, it was stable within a wide range of pH (2-10). The substance from P. putida T01 strain was bactericidal to Escherichia coli. SDS-PAGE analysis of the partial purified supernatant of strain T01 revealed a BLS with an approximate molecular mass of 8 kDa. Therefore, the results of this study show that P. putida strain T01 produces a BLS with a higher activity spectrum, which may find application in human medicine and in minimally processed food preservation. © 2014 APMIS. Published by John Wiley & Sons Ltd.

  7. Bacteriocin production by Lactobacillus pentosus ST712BZ isolated from boza Bacteriocina produzida por Lactobacillus pentosus ST712BZ isolad de boza

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    Svetoslav D. Todorov

    2007-03-01

    Full Text Available Bacteriocin ST712BZ (14.0kDa in size inhibits the growth of Lactobacillus casei,Escherichia coli, Pseudomonas aeruginosa,Enterococcus faecalis, Klebsiella pneumoniae and Lactobacillus curvatus. Growth of strain ST712BZ in BHI, M17, soy milk and molasses was similar to growth in MRS, with optimal bacteriocin production (12800AU/mL recorded in MRS after 24h. The same level of bacteriocin production (12800AU/mL was recorded in MRS broth with an initial pH of 6.5, 6.0 and 5.5. However, MRS broth (pH 6.5 supplemented with 1mM EDTA, yielded only 6400AU/mL. Low levels of bacteriocin activity were recorded in MRS broth with an initial pH of 5.0 and 4.5. Of all media compositions tested, MRS supplemented with tryptone (20.0g/L, glucose (20.0 to 40.0g/L, mannose (20.0g/L, vitamin B12, or vitamin C yielded 12800AU/mL. Glycerol concentrations of 1.0g/L and higher repressed bacteriocin production. Maximal bacteriocin activity (25600AU/mL was recorded in MRS supplemented with Vit. B1 or DL-6,8-thioctic acid.A bacteriocina ST712BZ produzida par Lactobacillus pentosus (peso molecular de 14,0kDa inibe o crescimento de Lactobacillus casei,Escherichia coli, Pseudomonas aeruginosa,Enterococcus faecalis, Klebsiella pneumoniae e Lactobacillus curvatus. O crescimento de L. pentosus ST712BZ em BHI, M17, leite de soja e melaços foi semelhante ao observado em MRS, registando-se a produção máxima de bacteriocina (12800UA/mL em MRS após 24 h. Observou-se o mesmo nível de produção de bacteriocina (12800UA/mL em caldo MRS com pH inicial de 6,5, 6,0 e 5,5. No entanto, em caldo MRS (pH 6,5 suplementado com 1 mM de EDTA a produção apenas atingiu 6400UA/mL. Os níveis de atividade bacteriocinogênica detectados em caldo MRS com um pH inicial de 5,0 e 4,5 foram baixos. De todas as fórmulas de meios de cultura testadas a que apresentou a atividade máxima 12800UA/mL foi MRS suplemento de triptona (20,0g/L, glicose (20,0 e 40,0 g/L, manose (20.0 g/L, vitamina B12 e

  8. Improvements in the quality and shelf life of kimchi by fermentation with the induced bacteriocin-producing strain, Leuconostoc citreum GJ7 as a starter.

    Science.gov (United States)

    Chang, Ji Yoon; Chang, Hae Choon

    2010-03-01

    To improve the quality and self-life of kimchi, the induced bacteriocin-producing lactic acid bacteria (LAB), Leuconostoc citreum GJ7, was introduced into kimchi fermentation as a starter. The kimchi preparations were incubated at 7 degrees C for 12 to 15 d, and then stored at -1 degrees C. Thereafter, changes in their characteristics were monitored for 125 d. When a kimchi starter was introduced into a nonsterile and open kimchi fermentation system, over-ripening of kimchi was prevented during 125 d of storage. In the starter kimchi, Leuc. citreum GJ7 was the dominant organism, comprising 70% to 90% of the total flora, and no yeasts were detected during the entire storage period. However, in the nonstarter kimchi, the predominant LAB could not be determined and yeasts were detected after 50 d of storage. The viable cell number of the starter kimchi was 2 log CFU/mL higher than in the nonstarter kimchi at 125 d of storage. The texture (firmness) of the starter kimchi at 95 to 125 d of storage was similar to that of the nonstarter kimchi at 20 d of storage. Sensory evaluations of texture, off-flavor, and carbonated mouthfeel were significantly improved by the starter-fermentation. The results indicate that the application of the bacteriocin-enhanced Leuc. citreum GJ7 as a starter culture exerts microbial control, prevents over-ripening, and extends the shelf life of kimchi. Presently, we have shown that under the optimum fermentation condition the induced bacteriocin-producing LAB, Leuc. citreum GJ7, can regulate natural kimchi fermentation and has extended dominance within the microbial ecology of kimchi. The result is improved quality and shelf life of kimchi. Moreover, to control the growth of other microorganisms in open-fermentation and nonsterile conditions, this system may be usefully adapted for other food or environmental control systems.

  9. Effect of supplementation of yeast with bacteriocin and culture on growth performance, cecal fermentation, microbiota composition, and blood characteristics in broiler chickens

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    C. Y. Chen

    2017-02-01

    Full Text Available Objective The aim of the present study was to investigate the effect of yeast with bacteriocin and Lactobacillus cultures (mixture of Lactobacillus agilis BCRC 10436 and Lactobacillus reuteri BCRC 17476 supplements, alone or in combination, on broiler chicken performance. Methods A total of 300, 1-d-old healthy broiler chickens were randomly divided into five treatment groups: i basal diet (control, ii basal diet+0.25% yeast (Saccharomyces cerevisiae (YC, iii basal diet+0.25% yeast with bacteriocin (BA, iv basal diet+Lactobacillus cultures (LAB, and v basal diet +0.25% yeast with bacteriocin+Lactobacillus cultures (BA+LAB. Growth performance, cecal microbiota, cecal fermentation products, and blood biochemistry parameters were determined when chickens were 21 and 35 d old. Results The supplementation of YC, BA, and BA+LAB resulted in a significantly better feed conversion rate (FCR than that of the control group during 1 to 21 d (p<0.05. The LAB supplementation had a significant effect on the presence of Lactobacillus in the ceca at 35 d. None of the supplements had an effect on relative numbers of L. agilis and L. reuter at 21 d, but the BA supplementation resulted in the decrease of both Lactobacillus strains at 35 d. The BA+LAB supplementation resulted in higher short chain fatty acid (SCFA in the ceca, but LAB supplementation significantly decreased the SCFA at 35 d (p<0.05. All treatments tended to decrease ammonia concentration in the ceca at 21 d, especially in the LAB treatment group. The BA supplementation alone decreased the triacylglycerol (TG concentration significantly at 21 d (p<0.05, but the synergistic effect of BA and LAB supplementation was required to reduce the TG concentration at 35 d. The YC supplementation tended to increase the plasma cholesterol at 21 d and 35 d. However, the BA supplementation significantly decreased the cholesterol and low density lipoprotein cholesterol level at 35 d. In conclusion, the BA

  10. Biopreservative Efficacy of Bacteriocin BacFL31 in Raw Ground Turkey Meat in terms of Microbiological, Physicochemical, and Sensory Qualities.

    Science.gov (United States)

    Chakchouk-Mtibaa, Ahlem; Smaoui, Slim; Ktari, Naourez; Sellem, Imen; Najah, Soumaya; Karray-Rebai, Ines; Mellouli, Lotfi

    2017-01-01

     The effect of the semi purified bacteriocin BacFL31 at 200 and 400 AU/g on the shelf life of refrigerated raw ground turkey meat was investigated. The microbiological, physicochemical, and sensory properties of the meat samples were examined during refrigerated storage. The findings indicated that BacFL31 treatments were effective (pturkey meat samples during refrigerated storage. These results suggest that BacFL31 could be considered a promising candidate for future application as an additive to preserve the raw turkey meat during storage at 4℃.

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

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    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

  12. Leuconostoc carnosum 4010 has the potential for use as a protective culture for vacuum-packed meats: culture isolation, bacteriocin identification, and meat application experiments

    DEFF Research Database (Denmark)

    Budde, B.B.; Hornbæk, T.; Jacobsen, T.

    2003-01-01

    A new culture, Leuconostoc carnosum 4010, for biopreservation of vacuum-packed meats is described. The culture originated from bacteriocin-producing lactic acid bacteria (LAB) naturally present in vacuum-packed meat products. Approximately, 72,000 colonies were isolated from 48 different vacuum......-packaged meat sausage immediately reduced the number of viable Listeria monocytogenes cells to a level below the detection limit and no increase of L. monocytogenes was observed during storage at 5 degreesC for 21 days. The results presented demonstrate that Leuc. carnosum 4010 is suitable as a new protective...... culture for cold-stored, cooked, sliced, and vacuum-packed meat products....

  13. Molecular detection and sensitivity to antibiotics and bacteriocins of pathogens isolated from bovine mastitis in family dairy herds of central Mexico.

    Science.gov (United States)

    León-Galván, Ma Fabiola; Barboza-Corona, José E; Lechuga-Arana, A Arianna; Valencia-Posadas, Mauricio; Aguayo, Daniel D; Cedillo-Pelaez, Carlos; Martínez-Ortega, Erika A; Gutierrez-Chavez, Abner J

    2015-01-01

    Thirty-two farms (n = 535 cows) located in the state of Guanajuato, Mexico, were sampled. Pathogens from bovine subclinical mastitis (SCM) and clinical mastitis (CLM) were identified by 16S rDNA and the sensitivity to both antibiotics and bacteriocins of Bacillus thuringiensis was tested. Forty-six milk samples were selected for their positive California Mastitis Test (CMT) (≥3) and any abnormality in the udder or milk. The frequency of SCM and CLM was 39.1% and 9.3%, respectively. Averages for test day milk yield (MY), lactation number (LN), herd size (HS), and number of days in milk (DM) were 20.6 kg, 2.8 lactations, 16.7 animals, and 164.1 days, respectively. MY was dependent on dairy herd (DH), LN, HS, and DM (P resistant to penicillin, clindamycin, ampicillin, and cefotaxime. Bacteriocins synthesized by Bacillus thuringiensis inhibited the growth of multiantibiotic resistance bacteria such as S. agnetis, S. equorum, Streptococcus uberis, Brevibacterium stationis, and Brachybacterium conglomeratum, but they were not active against S. sciuri, a microorganism that showed an 84% resistance to antibiotics tested in this study.

  14. Molecular Detection and Sensitivity to Antibiotics and Bacteriocins of Pathogens Isolated from Bovine Mastitis in Family Dairy Herds of Central Mexico

    Science.gov (United States)

    León-Galván, Ma. Fabiola; Barboza-Corona, José E.; Lechuga-Arana, A. Arianna; Valencia-Posadas, Mauricio; Aguayo, Daniel D.; Cedillo-Pelaez, Carlos; Martínez-Ortega, Erika A.; Gutierrez-Chavez, Abner J.

    2015-01-01

    Thirty-two farms (n = 535 cows) located in the state of Guanajuato, Mexico, were sampled. Pathogens from bovine subclinical mastitis (SCM) and clinical mastitis (CLM) were identified by 16S rDNA and the sensitivity to both antibiotics and bacteriocins of Bacillus thuringiensis was tested. Forty-six milk samples were selected for their positive California Mastitis Test (CMT) (≥3) and any abnormality in the udder or milk. The frequency of SCM and CLM was 39.1% and 9.3%, respectively. Averages for test day milk yield (MY), lactation number (LN), herd size (HS), and number of days in milk (DM) were 20.6 kg, 2.8 lactations, 16.7 animals, and 164.1 days, respectively. MY was dependent on dairy herd (DH), LN, HS, and DM (P < 0.01), and correlations between udder quarters from the CMT were around 0.49 (P < 0.01). Coagulase-negative staphylococci were mainly identified, as well as Staphylococcus aureus, Streptococcus uberis, Brevibacterium stationis, B. conglomeratum, and Staphylococcus agnetis. Bacterial isolates were resistant to penicillin, clindamycin, ampicillin, and cefotaxime. Bacteriocins synthesized by Bacillus thuringiensis inhibited the growth of multiantibiotic resistance bacteria such as S. agnetis, S. equorum, Streptococcus uberis, Brevibacterium stationis, and Brachybacterium conglomeratum, but they were not active against S. sciuri, a microorganism that showed an 84% resistance to antibiotics tested in this study. PMID:25815326

  15. Mode of action and in vitro susceptibility of mastitis pathogens to macedocin ST91KM and preparation of a teat seal containing the bacteriocin

    Directory of Open Access Journals (Sweden)

    Renee Pieterse

    2010-03-01

    Full Text Available Mastitis is considered to be the most economically costly disease affecting the dairy industry. Regular dosage of animals with antibiotics, including use of prophylactic concentrations, may select for resistant strains. The purpose of this study was to determine the mode of action of a new bacteriocin (macedocin ST91KM, to evaluate the antimicrobial resistance of mastitis pathogens to antibiotics commonly used in treatment remedies, and to introduce the possible use of an alternative antimicrobial agent. The bacteriocin macedocin ST91KM, produced by Streptococcus gallolyticus subsp. macedonicus ST91KM, is bactericidal to Streptococcus agalactiae, Streptococcus dysgalactiae, Streptococcus uberis and Staphylococcus aureus associated with mastitis infections, including strains resistant to methicillin and oxacillin. Sensitive cells were deformed and secreted nucleotides, K+ and β-galactosidase when exposed to macedocin ST91KM. Adsorption of the peptide to target cells decreased in the presence of solvents, suggesting that receptors on the cell surfaces have lipid moieties. No adsorption was recorded in the presence of MgCl2, KI and Na2CO3, suggesting that ionic strength plays an important role. A teat seal preparation containing macedocin ST91KM effectively released the peptide and inhibited the growth of S. agalactiae. Macedocin ST91KM could form the basis for alternative dry cow therapy to prevent mastitis infections in dairy cows as it is effective against pathogens that display resistance to conventional antibiotic therapy.

  16. Bacteriocin-like substances of Lactobacillus curvatus P99: characterization and application in biodegradable films for control of Listeria monocytogenes in cheese.

    Science.gov (United States)

    Marques, Juliana de Lima; Funck, Graciele Daiana; Dannenberg, Guilherme da Silva; Cruxen, Claudio Eduardo Dos Santos; Halal, Shanise Lisie Mello El; Dias, Alvaro Renato Guerra; Fiorentini, Ângela Maria; Silva, Wladimir Padilha da

    2017-05-01

    The aim of this study was to evaluate the effectiveness of a biodegradable film, with antimicrobial metabolites produced by Lactobacillus curvatus P99 incorporated, targeting the control of Listeria monocytogenes in sliced "Prato" cheese. Tests were performed to evaluate the spectrum of action of cell-free supernatant (CFS) of P99 against different microorganisms, as well as to detect the minimum inhibitory (MIC) and bactericidal (MBC) concentrations against L. monocytogenes Scott A. The detection of genes that encode for the production of bacteriocins and evaluation of their expression were performed. Antimicrobial films were prepared, followed by in vitro and in situ analysis. The MIC and MBC of CFS against L. monocytogenes Scott A was 15.6 μL/mL and 62.5 μL/mL, respectively. Lactobacillus curvatus P99 presented two genes coding for the bacteriocins, which were expressed. Films with added MBC showed activity against different indicator microorganisms and were able to control L. monocytogenes Scott A when used in sliced "Prato" cheese. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Engineered strains of Streptococcus macedonicus towards an osmotic stress resistant phenotype retain their ability to produce the bacteriocin macedocin under hyperosmotic conditions.

    Science.gov (United States)

    Anastasiou, Rania; Driessche, Gonzalez Van; Boutou, Effrossyni; Kazou, Maria; Alexandraki, Voula; Vorgias, Constantinos E; Devreese, Bart; Tsakalidou, Effie; Papadimitriou, Konstantinos

    2015-10-20

    Streptococcus macedonicus ACA-DC 198 produces the bacteriocin macedocin in milk only under low NaCl concentrations (<1.0%w/v). The thermosensitive plasmid pGh9:ISS1 was employed to generate osmotic stress resistant (osmr) mutants of S. macedonicus. Three osmr mutants showing integration of the vector in unique chromosomal sites were identified and the disrupted loci were characterized. Interestingly, the mutants were able to grow and to produce macedocin at considerably higher concentrations of NaCl compared to the wild-type (up to 4.0%w/v). The production of macedocin under hyperosmotic conditions solely by the osmr mutants was validated by the well diffusion assay and by mass spectrometry analysis. RT-PCR experiments demonstrated that the macedocin biosynthetic regulon was transcribed at high salt concentrations only in the mutants. Mutant osmr3, the most robust mutant, was converted in its markerless derivative (osmr3f). Co-culture of S. macedonicus with spores of Clostridium tyrobutyricum in milk demonstrated that only the osmr3f mutant and not the wild-type inhibited the growth of the spores under hyperosmotic conditions (i.e., 2.5%w/v NaCl) due to the production of macedocin. Our study shows how genetic manipulation of a strain towards a stress resistant phenotype could improve bacteriocin production under conditions of the same stress. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Bacteriocins from Lactobacillus plantarum production, genetic organization and mode of action: produção, organização genética e modo de ação Bacteriocinas de Lactobacillus plantarum

    Directory of Open Access Journals (Sweden)

    Svetoslav D. Todorov

    2009-06-01

    Full Text Available Bacteriocins are biologically active proteins or protein complexes that display a bactericidal mode of action towards usually closely related species. Numerous strains of bacteriocin producing Lactobacillus plantarum have been isolated in the last two decades from different ecological niches including meat, fish, fruits, vegetables, and milk and cereal products. Several of these plantaricins have been characterized and the aminoacid sequence determined. Different aspects of the mode of action, fermentation optimization and genetic organization of the bacteriocin operon have been studied. However, numerous of bacteriocins produced by different Lactobacillus plantarum strains have not been fully characterized. In this article, a brief overview of the classification, genetics, characterization, including mode of action and production optimization for bacteriocins from Lactic Acid Bacteria in general, and where appropriate, with focus on bacteriocins produced by Lactobacillus plantarum, is presented.Bacteriocinas são proteínas ou complexos protéicos biologicamente ativos que apresentam atividade bactericida contra espécies relacionadas. Nas ultimas duas décadas, várias cepas de Lactobacillus plantarum produtoras de bacteriocinas foram isoladas de diferentes nichos ecológicos como carnes, peixes, frutas, vegetais e produtos lácteos e de cereais. Várias plantaricinas foram caracterizadas e suas seqüências de aminoácidos determinadas. Diferentes aspectos do modo de ação, otimização da fermentação e organização genética já foram estudados. Entretanto, muitas bacteriocinas produzidas por diferentes cepas de Lactobacillus plantarum ainda não foram completamente caracterizadas.Nesse artigo, apresenta-se uma breve revisão sobre a classificação, genética, caracterização, modo de ação, e otimização da produção de bacteriocinas de bactérias láticas em geral, e, quando apropriado, de bacteriocinas de Lactobacillus plantarum.

  19. Partial characterization of bacteriocin-like compounds from two strains of Bacillus cereus with biological activity against Paenibacillus larvae, the causal agent of American Foulbrood disease.

    Science.gov (United States)

    Minnaard, J; Alippi, A M

    2016-12-01

    American Foulbrood (AFB), caused by the spore-forming Gram-positive bacterium Paenibacillus larvae, is the most severe bacterial disease affecting honeybees worldwide. Two bacterial isolates showing specific inhibitory activity against P. larvae were identified as Bacillus cereus by 16S rDNA sequencing. Antagonistic compounds were obtained from cell-free supernatants of strains m6c and m387 growing on Trypticase Soy Broth and concentrated by NH 4 SO 4 precipitation, ultrafiltration and butanol extraction. Both compounds were characterized as bacteriocin-like inhibitory substances (BLIS). BLISm6c and BLISm387 were stable at 70°C for 30 min and active in the pH range from 3 to 7. The antibacterial activity was completely lost at pH values higher than 8 or temperatures >80°C. Both BLIS have a narrow activity range and highly inhibit the growth of P. larvae. BLISm6c and BLISm387 differ from each other and other BLIS reportedly produced by B. cereus with regard to their molecular weights, antibacterial activity, minimal inhibitory concentration values and sensitivity to degradative enzymes. The findings of this study suggest that BLISm6c and BLISm387 can potentially be used to control AFB. An Integrated Pest Management (IPM) approach is needed to ensure the sustainability of the beekeeping industry due to the increasing demand for organic honey and the reduction of dependence on antibiotics. Biocontrol agents produced by bacteria isolated from apiarian sources seem promising and able to combine with an IPM strategy. The most significant findings of this study are the characterization of bacteriocin-like compounds (BLIS) obtained from two strains of Bacillus cereus isolated from honey. Both BLIS have a narrow activity range and highly inhibit the growth of Paenibacillus larvae, the causal agent of American Foulbrood disease of honey bees. © 2016 The Society for Applied Microbiology.

  20. Isolation of Lactococcus lactis Mutants Simultaneously Resistant to the Cell Wall-Active Bacteriocin Lcn972, Lysozyme, Nisin, and Bacteriophage c2

    Science.gov (United States)

    Roces, Clara; Courtin, Pascal; Kulakauskas, Saulius; Rodríguez, Ana; Chapot-Chartier, Marie-Pierre

    2012-01-01

    Lactococcin 972 (Lcn972) is a nonlantibiotic bacteriocin that inhibits cell wall biosynthesis by binding to lipid II. In this work, two mutants resistant to Lcn972, Lactococcus lactis D1 and D1-20, with high (>320 arbitrary units [AU]/ml) and low (80 AU/ml) susceptibilities, respectively, have been isolated. Resistance to Lcn972 did not impose a burden to growth under laboratory conditions, nor did it substantially alter the physicochemical properties of the cell surface. However, the peptidoglycan of the mutants featured a higher content of muropeptides with tripeptide side chains than the wild-type strain, linking for the first time peptidoglycan remodelling to bacteriocin resistance. Moreover, L. lactis lacking a functional d,d-carboxypeptidase DacA (i.e., with a high content of pentapeptide side chain muropeptides) was shown to be more susceptible to Lcn972. Cross-resistance to lysozyme and nisin and enhanced susceptibility to penicillin G and bacitracin was also observed. Intriguingly, the Lcn972-resistant mutants were not infected by the lytic phage c2 and less efficiently infected by phage sk1. Lack of c2 infectivity was linked to a 22.6-kbp chromosomal deletion encompassing the phage receptor protein gene pip. The deletion also included maltose metabolic genes and the two-component system (TCS) F. However, a clear correlation between these genes and resistance to Lcn972 could not be clearly established, pointing to the presence of as-yet-unidentified mutations that account for Lcn972 resistance. PMID:22504807

  1. Both IIC and IID Components of Mannose Phosphotransferase System Are Involved in the Specific Recognition between Immunity Protein PedB and Bacteriocin-Receptor Complex.

    Directory of Open Access Journals (Sweden)

    Wanli Zhou

    Full Text Available Upon exposure to exogenous pediocin-like bacteriocins, immunity proteins specifically bind to the target receptor of the mannose phosphotransferase system components (man-PTS IIC and IID, therefore preventing bacterial cell death. However, the specific recognition of immunity proteins and its associated target receptors remains poorly understood. In this study, we constructed hybrid receptors to identify the domains of IIC and/or IID recognized by the immunity protein PedB, which confers immunity to pediocin PA-1. Using Lactobacillus plantarum man-PTS EII mutant W903, the IICD components of four pediocin PA-1-sensitive strains (L. plantarum WQ0815, Leuconostoc mesenteroides 05-43, Lactobacillus salivarius REN and Lactobacillus acidophilus 05-172 were respectively co-expressed with the immunity protein PedB. Well-diffusions assays showed that only the complex formed by LpIICD from L. plantarum WQ0815 with pediocin PA-1 could be recognized by PedB. In addition, a two-step PCR approach was used to construct hybrid receptors by combining LpIIC or LpIID recognized by PedB with the other three heterologous IID or IIC compounds unrecognized by PedB, respectively. The results showed that all six hybrid receptors were recognized by pediocin PA-1. However, when IIC or IID of L. plantarum WQ0815 was replaced with any corresponding IIC or IID component from L. mesenteroides 05-43, L. salivarius REN and L. acidophilus 05-172, all the hybrid receptors could not be recognized by PedB. Taken altogether, we concluded that both IIC and IID components of the mannose phosphotransferase system play an important role in the specific recognition between the bacteriocin-receptor complex and the immunity protein PedB.

  2. Genomic and proteomic characterization of bacteriocin-producing Leuconostoc mesenteroides strains isolated from raw camel milk in two southwest Algerian arid zones.

    Science.gov (United States)

    Benmechernene, Zineb; Fernández-No, Inmaculada; Quintela-Baluja, Marcos; Böhme, Karola; Kihal, Mebrouk; Calo-Mata, Pilar; Barros-Velázquez, Jorge

    2014-01-01

    Information on the microbiology of camel milk is very limited. In this work, the genetic characterization and proteomic identification of 13 putative producing bacteriocin Leuconostoc strains exhibiting antilisterial activity and isolated from camel milk were performed. DNA sequencing of the 13 selected strains revealed high homology among the 16S rRNA genes for all strains. In addition, 99% homology with Leuconostoc mesenteroides was observed when these sequences were analysed by the BLAST tool against other sequences from reference strains deposited in the Genbank. Furthermore, the isolates were characterized by matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDITOF MS) which allowed for the identification of 2 mass peaks 6242 m/z and 5118 m/z that resulted to be specific to the species L. mesenteroides. Remarkably, the phyloproteomic tree provided more intraspecific information of L. mesenteroides than phylogenetic analysis. Accordingly, phyloproteomic analysis grouped L. mesenteroides strains into different subbranches, while all L. mesenteroides isolates were grouped in the same branch according to phylogenetic analysis. This study represents, to our knowledge, the first report on the use of MALDI-TOF MS on the identification of LAB isolated from camel milk.

  3. Genomic and Proteomic Characterization of Bacteriocin-Producing Leuconostoc mesenteroides Strains Isolated from Raw Camel Milk in Two Southwest Algerian Arid Zones

    Directory of Open Access Journals (Sweden)

    Zineb Benmechernene

    2014-01-01

    Full Text Available Information on the microbiology of camel milk is very limited. In this work, the genetic characterization and proteomic identification of 13 putative producing bacteriocin Leuconostoc strains exhibiting antilisterial activity and isolated from camel milk were performed. DNA sequencing of the 13 selected strains revealed high homology among the 16S rRNA genes for all strains. In addition, 99% homology with Leuconostoc mesenteroides was observed when these sequences were analysed by the BLAST tool against other sequences from reference strains deposited in the Genbank. Furthermore, the isolates were characterized by matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDITOF MS which allowed for the identification of 2 mass peaks 6242 m/z and 5118 m/z that resulted to be specific to the species L. mesenteroides. Remarkably, the phyloproteomic tree provided more intraspecific information of L. mesenteroides than phylogenetic analysis. Accordingly, phyloproteomic analysis grouped L. mesenteroides strains into different subbranches, while all L. mesenteroides isolates were grouped in the same branch according to phylogenetic analysis. This study represents, to our knowledge, the first report on the use of MALDI-TOF MS on the identification of LAB isolated from camel milk.

  4. Detection and partial characterization of a bacteriocin-like substance produced by Lactobacillus fermentum CS57 isolated from human vaginal secretions.

    Science.gov (United States)

    Sabia, Carla; Anacarso, Immacolata; Bergonzini, Alberto; Gargiulo, Raffaele; Sarti, Mario; Condò, Carla; Messi, Patrizia; de Niederhausern, Simona; Iseppi, Ramona; Bondi, Moreno

    2014-04-01

    Lactobacilli (150) from human vaginal secretions were tested for the production of antimicrobial substances which can provide a physiological defense against the pathogenic microorganisms in the vaginal area. Sixteen of the isolates (10.6%) showed antibacterial activity against one or several closely related microorganisms used as indicators. Lactobacillus fermentum CS57 was the best producer and secretes a bacteriocin-like substance (BLS) with antagonistic activity against Streptococcus agalactiae and Candida albicans. The compound was susceptible to the proteolytic enzymes and was heat labile. The mode of action was identified as bactericidal. The crude activity of the L. fermentum CS57 BLS was linked to a substance with a molecular weight larger than 30 kDa. Plasmid analysis of L. fermentum CS57 revealed the presence of a plasmid band with molecular weight of 54.7 kb. All L. fermentum CS57 non-producer variants (BLS-) obtained by curing experiments, showed loss of plasmid band and were susceptible to the BLS of the original strain. Therefore antimicrobial activity and immunity production seem to be linked to genes located on that same plasmid. Taking into account our results, L. fermentum CS57 could be considered a candidate for potential use as probiotic for the prophylaxis of vaginal human infections. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Whole-genome sequencing of mutants with increased resistance against the two-peptide bacteriocin plantaricin JK reveals a putative receptor and potential docking site.

    Science.gov (United States)

    Ekblad, Bie; Nissen-Meyer, Jon; Kristensen, Tom

    2017-01-01

    By whole-genome sequencing of resistant mutants, a putative receptor for plantaricin JK, a two-peptide bacteriocin produced by some Lactobacillus plantarum strains, was identified in Lactobacillus plantarum NCFB 965 and Weissella viridescens NCFB 1655. The receptors of the two species had 66% identical amino acid sequences and belong to the amino acid-polyamine-organocation (APC) transporter protein family. The resistant mutants contained point mutations in the protein-encoding gene resulting in either premature stop codons, leading to truncated versions of the protein, or single amino acid substitutions. The secondary structure of the W. viridescens protein was predicted to contain 12 transmembrane (TM) helices, a core structure shared by most members of the APC protein family. The single amino acid substitutions that resulted in resistant strains were located in a confined region of the protein that consists of TM helix 10, which is predicted to be part of an inner membrane pore, and an extracellular loop between TM helix 11 and 12. By use of template-based modeling a 3D structure model of the protein was obtained, which visualizes this mutational hotspot region and further strengthen the hypothesis that it represents a docking site for plantaricin JK.

  6. Partial Purification and Characterization of the Mode of Action of Enterocin S37: A Bacteriocin Produced by Enterococcus faecalis S37 Isolated from Poultry Feces

    Directory of Open Access Journals (Sweden)

    Y. Belguesmia

    2010-01-01

    Full Text Available The aim of this research was to purify and characterize the mode of action of enterocin S37, a bacteriocin produced by Enterococcus faecalis S37, a strain recently isolated from the chicken feces. Enterocin S37 has a molecular weight comprised between 4 and 5 kDa. It remained active after 1 h at 80oC and at pH values ranging from 4.0 to 9.0. Furthermore, cell-free supernatant of Enterococcus faecalis S37 and purified enterocin S37 were active against Gram-positive bacteria including Listeria monocytogenes EGDe, L. innocua F, Enterococcus faecalis JH2-2, and Lactobacillus brevis F145. The purification of enterocin S37 was performed by ammonium sulfate precipitation followed up by hydrophobic-interaction chromatography procedures. Treatment of enterocin S37 with proteinase K, -chymotrypsin, and papain confirmed its proteinaceous nature, while its treatment with lysozyme and lipase resulted in no alteration of activity. Enterocin S37 is hydrophobic, anti-Listeria and likely acting by depletion of intracellular K+ ions upon action on KATP channels. This study contributed to gain more insights into the mode of action of enterocins.

  7. Isolation of Pediococcus acidilactici Kp10 with ability to secrete bacteriocin-like inhibitory substance from milk products for applications in food industry

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    Abbasiliasi Sahar

    2012-11-01

    Full Text Available Abstract Background Lactic acid bacteria (LAB can be isolated from traditional milk products. LAB that secrete substances that inhibit pathogenic bacteria and are resistant to acid, bile, and pepsin but not vancomycin may have potential in food applications. Results LAB isolated from a range of traditional fermented products were screened for the production of bacteriocin-like inhibitory substances. A total of 222 LAB strains were isolated from fermented milk products in the form of fresh curds, dried curds, and ghara (a traditional flavor enhancer prepared from whey, and fermented cocoa bean. Eleven LAB isolates that produced antimicrobial substances were identified as Lactococcus lactis, Lactobacillus plantarum, and Pediococcus acidilactici strains by biochemical methods and 16S rDNA gene sequencing. Of these, the cell-free supernatant of Kp10 (P. acidilactici most strongly inhibited Listeria monocytogenes. Further analysis identified the antimicrobial substance produced by Kp10 as proteinaceous in nature and active over a wide pH range. Kp10 (P. acidilactici was found to be catalase-negative, able to produce β-galactosidase, resistant to bile salts (0.3% and acidic conditions (pH 3, and susceptible to most antibiotics. Conclusion Traditionally prepared fermented milk products are good sources of LAB with characteristics suitable for industrial applications. The isolate Kp10 (P. acidilactici shows potential for the production of probiotic and functional foods.

  8. Bacteriocin protein BacL1 of Enterococcus faecalis targets cell division loci and specifically recognizes L-Ala2-cross-bridged peptidoglycan.

    Science.gov (United States)

    Kurushima, Jun; Nakane, Daisuke; Nishizaka, Takayuki; Tomita, Haruyoshi

    2015-01-01

    Bacteriocin 41 (Bac41) is produced from clinical isolates of Enterococcus faecalis and consists of two extracellular proteins, BacL1 and BacA. We previously reported that BacL1 protein (595 amino acids, 64.5 kDa) is a bacteriolytic peptidoglycan D-isoglutamyl-L-lysine endopeptidase that induces cell lysis of E. faecalis when an accessory factor, BacA, is copresent. However, the target of BacL1 remains unknown. In this study, we investigated the targeting specificity of BacL1. Fluorescence microscopy analysis using fluorescent dye-conjugated recombinant protein demonstrated that BacL1 specifically localized at the cell division-associated site, including the equatorial ring, division septum, and nascent cell wall, on the cell surface of target E. faecalis cells. This specific targeting was dependent on the triple repeat of the SH3 domain located in the region from amino acid 329 to 590 of BacL1. Repression of cell growth due to the stationary state of the growth phase or to treatment with bacteriostatic antibiotics rescued bacteria from the bacteriolytic activity of BacL1 and BacA. The static growth state also abolished the binding and targeting of BacL1 to the cell division-associated site. Furthermore, the targeting of BacL1 was detectable among Gram-positive bacteria with an L-Ala-L-Ala-cross-bridging peptidoglycan, including E. faecalis, Streptococcus pyogenes, or Streptococcus pneumoniae, but not among bacteria with alternate peptidoglycan structures, such as Enterococcus faecium, Enterococcus hirae, Staphylococcus aureus, or Listeria monocytogenes. These data suggest that BacL1 specifically targets the L-Ala-L-Ala-cross-bridged peptidoglycan and potentially lyses the E. faecalis cells during cell division. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  9. Sil: a Streptococcus iniae bacteriocin with dual role as an antimicrobial and an immunomodulator that inhibits innate immune response and promotes S. iniae infection.

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    Mo-fei Li

    Full Text Available Streptococcus iniae is a Gram-positive bacterium and a severe pathogen to a wide range of economically important fish species. In addition, S. iniae is also a zoonotic pathogen and can cause serious infections in humans. In this study, we identified from a pathogenic S. iniae strain a putative bacteriocin, Sil, and examined its biological activity. Sil is composed of 101 amino acid residues and shares 35.6% overall sequence identity with the lactococcin 972 of Lactococcus lactis. Immunoblot analysis showed that Sil was secreted by S. iniae into the extracellular milieu. Purified recombinant Sil (rSil exhibited a dose-dependent inhibitory effect on the growth of Bacillus subtilis but had no impact on the growths of other 16 Gram-positive bacteria and 10 Gram-negative bacteria representing 23 different bacterial species. Treatment of rSil by heating at 50°C abolished the activity of rSil. rSil bound to the surface of B. subtilis but induced no killing of the target cells. Cellular study revealed that rSil interacted with turbot (Scophthalmus maximus head kidney monocytes and inhibited the innate immune response of the cells, which led to enhanced cellular infection of S. iniae. Antibody blocking of the extracellular Sil produced by S. iniae significantly attenuated the infectivity of S. iniae. Consistent with these in vitro observations, in vivo study showed that administration of turbot with rSil prior to S. iniae infection significantly increased bacterial dissemination and colonization in fish tissues. Taken together, these results indicate that Sil is a novel virulence-associated bacteriostatic and an immunoregulator that promotes S. iniae infection by impairing the immune defense of host fish.

  10. Bacteriocin-like activity of oral Fusobacterium nucleatum isolated from human and non-human primates Atividade semelhante a bacteriocina de Fusobacterium nucleatum orais isolados de primatas humanos e não-humanos

    Directory of Open Access Journals (Sweden)

    Elerson Gaetti-Jardim Júnior

    1999-12-01

    Full Text Available Fusobacterium nucleatum is indigenous of the human oral cavity and has been involved in different infectious processes. The production of bacteriocin-like substances may be important in regulation of bacterial microbiota in oral cavity. The ability to produce bacteriocin-like substances by 80 oral F. nucleatum isolates obtained from periodontal patients, healthy individuals and Cebus apella monkeys, was examinated. 17.5% of all tested isolates showed auto-antagonism and 78.8% iso- or hetero-antagonism. No isolate from monkey was capable to produce auto-inhibition. In this study, the antagonistic substances production was variable in all tested isolates. Most of the F. nucleatum showed antagonistic activity against tested reference strains. These data suggest a possible participation of these substances on the oral microbial ecology in humans and animals. However, the role of bacteriocins in regulating dental plaque microbiota in vivo is discussed.Fusobacterium nucleatum é indígena da cavidade oral humana e tem sido envolvido em diferentes processos infecciosos. A produção de substâncias semelhantes a bacteriocinas pode ser importante na regulação da microbiota bacteriana da cavidade oral. A capacidade de produzir substâncias tipo bacteriocina de 80 isolados de F. nucleatum orais, obtidos de pacientes com doença periodontal, indivíduos sadios e macaco Cebus apella, foi avaliada. 17,5% de todos os isolados mostrou auto-antagonismo e 78,8% iso- ou hetero-antagonismo. Nenhum isolado de macaco foi capaz de produzir auto-inibição. Neste estudo, a produção de substâncias antagonístas foi variável em todos os isolados testados. A maioria dos F. nucleatum mostrou atividade antagonísta para as cepas de referência testadas. Esses dados sugerem a possível participação dessas substâncias sobre a ecologia microbiana em humanos e animais. Entretanto, o papel das bacteriocinas na regulação da microbiota da placa dental in vivo

  11. The effect of pH and a bacteriocin (bovicin HC5) on Clostridium sporogenes MD1, a bacterium that has the ability to degrade amino acids in ensiled plant materials.

    Science.gov (United States)

    Flythe, Michael D; Russell, James B

    2004-02-01

    Fresh plant materials can be fermented and preserved as silage for cattle, but clostridia that deaminate amino acids increase pH. If the pH of the silage rises, spoilage microorganisms proliferate, and undesirable products accumulate. Rod-shaped, anaerobic bacteria with spores were isolated from fresh alfalfa, fresh corn, and silages. Strain MD1 had the highest specific activity of amino acid deamination, and it was most closely related to Clostridium botulinum A and B. However, because strain MD1 did not produce a toxin, it was classified as Clostridium sporogenes. Washed cell suspensions of C. sporogenes MD1 had specific activities as great as 690 nmol ammonia mg protein(-1) min(-1), and this rate did not decrease until the pH was less than 4.5. Batch cultures of C. sporogenes MD1 did not initiate growth if the initial pH was less than 5.0, but continuous cultures (0.1 h(-1) dilution rate) persisted until the pH in the culture vessel was 4.6. When C. sporogenes MD1 was co-cultured with a bacteriocin-producing Streptococcus bovis HC5, ammonia production was greatly reduced. The ability of S. bovis HC5 to inhibit strain MD1 was pH-dependent. When the pH was 5.5 or less, strain MD1 could no longer be detected. These latter results support the idea that bacteriocin-producing bacteria may be used to improve silage quality.

  12. Production of bacteriocin-like inhibitory substances (BLIS by Streptococcus salivarius strains isolated from the tongue and throat of children with and without sore throat Produção de substâncias inibidoras semelhantes à bacteriocina por cepas de Streptococcus salivarius, isoladas da língua e garganta de crianças com e sem dor de garganta

    Directory of Open Access Journals (Sweden)

    Vera Fantinato

    1999-12-01

    Full Text Available Streptococcus salivarius strains, isolated from children with and without sore throat, were tested for bacteriocin production against Streptococcus pyogenes. S. salivarius strains producing bacteriocin-like inhibitory substances (BLIS against S. pyogenes were more frequently found in children without sore throat. These results suggest that these children may be protected against sore throat by the presence of BLIS-positive S. salivarius strains.Cepas de Streptococcus salivarius, isoladas de crianças com e sem dor de garganta, foram testadas quanto à produção de bacteriocina contra Streptococcus pyogenes. Os resultados mostraram que as crianças que não tinham dor de garganta possuiam, na boca, cepas de bactérias produtoras de substâncias inibidoras semelhantes à bacteriocina contra S. pyogenes.

  13. Caracterização preliminar de bacteriocinas produzidas por seis cepas de bactérias láticas isoladas de produtos cárneos embalados a vácuo Preliminary characterization of bacteriocins produced by six lactic acid bacteria strains isolated from vacuum-packaged meat products

    Directory of Open Access Journals (Sweden)

    Elaine C. P. de Martinis

    2003-08-01

    Full Text Available No presente trabalho, foram estudadas as bacteriocinas produzidas por seis linhagens bacterianas: duas culturas Lactobacillus sake, duas de Lactobacillus curvatus, uma de Leuconostoc mesenteroides, uma de Leuconostoc sp 12. As atividades inibitórias foram quantificadas pelo método da diluição crítica, utilizando-se os indicadores Lactobacillus sake ATCC 15521 e Listeria monocytogenes. As bacteriocinas produzidas foram caracterizadas também quanto à sensibilidade a enzimas, faixa de temperatura na produção, termoestabilidade, estabilidade em diferentes pHs e modo de ação (bactericida ou bacteriostático frente a Listeria monocytogenes. Nenhuma bacteriocina foi destruída pela pepsina, mas todas foram sensíveis à proteinase K, tripsina e alfa-amilase (exceto a bacteriocina produzida por Leuconostoc sp 12, que foi insensível a alfa-amilase. Lactobacillus sake 1, Leuconostoc mesenteroides 11 e Lactobacillus sake 16 apresentaram atividade antilisterial, sendo a maior inibição observada para Lactobacillus sake 1 e Leuconostoc mesenteroides 11 (12.800UA/mL. Lactobacillus sake 1 e Lactobacillus curvatus 5 produziram as bacteriocinas mais termoestáveis. Lactobacillus sake 1 produziu a bacteriocina com maior estabilidade a variações de pH. Todas as bactérias láticas produziram bacteriocina entre 4ºC e 30ºC, sendo esta propriedade muito interessante para futuras aplicações em produtos cárneos refrigerados.In this work, the bacteriocins produced by six bacterial strains were studied (Lactobacillus sake 1, Lactobacillus curvatus 5, Leuconostoc mesenteroides 11, Leuconostoc sp 12, Lactobacillus curvatus 14 and Lactobacillus sake 16. Title of inhibitory activity was determined by critical dilution assay, using Lactobacillus sake ATCC 15521 and Listeria monocytogenes as indicator microorganisms. The inhibitory compounds were also characterized with respect to stability to the action of enzymes, thermostability, stability in several p

  14. Binding sequences for RdgB, a DNA damage-responsive transcriptional activator, and temperature-dependent expression of bacteriocin and pectin lyase genes in Pectobacterium carotovorum subsp. carotovorum.

    Science.gov (United States)

    Yamada, Kazuteru; Kaneko, Jun; Kamio, Yoshiyuki; Itoh, Yoshifumi

    2008-10-01

    Pectobacterium carotovorum subsp. carotovorum strain Er simultaneously produces the phage tail-like bacteriocin carotovoricin (Ctv) and pectin lyase (Pnl) in response to DNA-damaging agents. The regulatory protein RdgB of the Mor/C family of proteins activates transcription of pnl through binding to the promoter. However, the optimal temperature for the synthesis of Ctv (23 degrees C) differs from that for synthesis of Pnl (30 degrees C), raising the question of whether RdgB directly activates ctv transcription. Here we report that RdgB directly regulates Ctv synthesis. Gel mobility shift assays demonstrated RdgB binding to the P(0), P(1), and P(2) promoters of the ctv operons, and DNase I footprinting determined RdgB-binding sequences (RdgB boxes) on these and on the pnl promoters. The RdgB box of the pnl promoter included a perfect 7-bp inverted repeat with high binding affinity to the regulator (K(d) [dissociation constant] = 150 nM). In contrast, RdgB boxes of the ctv promoters contained an imperfect inverted repeat with two or three mismatches that consequently reduced binding affinity (K(d) = 250 to 350 nM). Transcription of the rdgB and ctv genes was about doubled at 23 degrees C compared with that at 30 degrees C. In contrast, the amount of pnl transcription tripled at 30 degrees C. Thus, the inverse synthesis of Ctv and Pnl as a function of temperature is apparently controlled at the transcriptional level, and reduced rdgB expression at 30 degrees C obviously affected transcription from the ctv promoters with low-affinity RdgB boxes. Pathogenicity toward potato tubers was reduced in an rdgB knockout mutant, suggesting that the RdgAB system contributes to the pathogenicity of this bacterium, probably by activating pnl expression.

  15. Evaluation of bacteriocin-producing Lactobacillus sakei 1 against Listeria monocytogenes 1/2a growth and haemolytic activity Avaliação de Lactobacillus sakei 1 produtor de bacteriocina frente a Listeria monocytogenes 1/2a e sua atividade hemolítica

    Directory of Open Access Journals (Sweden)

    Rafael C.R. Martinez

    2005-03-01

    Full Text Available Bacteriocin-producing Lactobacillus sakei 1 was cultivated in Brain-Heart Infusion broth (24 h at 25ºC. The culture supernatant was neutralized, filter sterilized and used to test the activity of bacteriocin against Listeria monocytogenes 1/2a, at 8ºC and 15ºC. Non-bacteriocinogenic Lactobacillus sakei ATCC 15521 was used as a negative control. L. monocytogenes 1/2a was inoculated in culture supernatant medium from L. sakei 1 and L. sakei ATCC 15521 and the listerial populations were determined after 0, 5 and 10 days. The bacteriocin production was quantified as arbitrary units per mL (AU/mL using agar antagonism test. Additionally, to investigate if L. monocytogenes virulence pattern could be changed after bactericion exposure, the ability of L. monocytogenes to cause haemolysis in sheep red blood cells was determined, before and after exposure to bacteriocin at 8ºC. In the presence of the antimicrobial peptide, at 8ºC, L. monocytogenes population decreased, but growth of resistant cells was observed. At 15ºC, there was no difference between test and control. Furthermore, the haemolytic activity of L. monocytogenes 1/2a was not altered by exposure to L. sakei 1 bacteriocin, which suggests no change in its virulence pattern.Lactobacillus sakei 1 produtor de bacteriocina foi cultivado em caldo Infusão Cérebro-Coração por 24h a 25ºC. O sobrenadante da cultura foi neutralizado, esterilizado por filtração e usado para testar a atividade da bacteriocina frente a Listeria monocytogenes 1/2a, a 8ºC e 15ºC. Lactobacillus sakei ATCC 15521 não bacteriocinogênico, foi utilizado como controle negativo. L. monocytogenes 1/2a foi inoculada no sobrenadante da cultura de L.sakei 1 e L. sakei ATCC 15521 e as populações listeriais foram determinadas após 0, 5 e 10 dias. A produção de bacteriocina foi quantificada como unidades arbitrárias por mL (UA/mL, utilizando-se o teste de antagonismo em ágar. Adicionalmente, para investigar se o padr

  16. Protocol for Initial Purification of Bacteriocin

    Science.gov (United States)

    2015-10-01

    REPORT DATE (DD-MM-YYYY) 30-10-2015 2. REPORT TYPE Final 3. DATES COVERED (From - To) February 2013 – August 2014 4. TITLE AND SUBTITLE PROTOCOL...microorganisms. 3 5. Test Organisms  Target bacteria – Bacillus anthracis Sterne, Staphylococcus aureus ATCC 27217, or Pseudomonas aeruginosa...freezer. 6. Procedures 6.1. Prepare Target Bacteria:  Inoculate a single colony of a fresh culture of Bacillus anthracis Sterne, Staphylococcus

  17. Lactobacillus acidophilus bacteriocin, from production to their ...

    African Journals Online (AJOL)

    activities toward closely related bacteria and undesirable harmful microorganisms. They are useful in the fields of food preservation or safety, health care, and pharmaceutical applications. The inhibition activity of these substances has been reported to be strain-dependent. Binding to the epithelial cell on the gastrointestinal ...

  18. Influence of bacteriocins produced by Lactobacillus plantarum BN in the shelf-life of refrigerated bovine meat Influência de bacteriocinas produzidas por Lactobacillus plantarum BN na vida útil de carne bovina refrigerada

    Directory of Open Access Journals (Sweden)

    Ângela M. Fiorentini

    2001-03-01

    Full Text Available Sugar cane molasses is a cheap by-product of the sugar cane industry. This product was used for growth and production of bacteriocins by Lactobacillus plantarum BN and evaluated for its potential application in the extension of the shelf-life of raw meat. Bovine meat cubes were dipped in the filtered and neutralized supernatant of the fermented broth (Treatment A and stored at 5ºC. Counts of psychrotrophic and mesophilic aerobic microorganisms, pH determination and total acidity were performed on meat cubes after 0, 3, 6, 9, 12 and 15 days. These determinations were also done in cubes dipped in a 6% lactic acid solution (treatment B and distilled water (treatment C. After 3 days, the counts of psychrotrophic microorganisms in cubes submitted to treatment A, B and C increased 0.38, 1.42 and 2.04 log cycles, respectively. The same happened with mesophilic microorganisms (0.31, 0.33 and 1.04 log cycles increases, respectively. On the sixth day, the psychrotrophic population in samples submitted to treatments A and B were 2.07 and 0.64 log cycles, respectively, lower than in the control samples (treatment C. Mesophilic microorganisms in these samples were 1.58 and 1.12 log cycles, respectively, lower than the controls. On the sixth day, only samples submitted to treatment A presented lower counts than those recommended by ICMSF as quality standards for raw meat (Melaço de cana de açúcar é um sub-produto barato da indústria açucareira. Esse produto foi empregado para o crescimento e produção de bacteriocina de Lactobacillus plantarum BN e avaliado quando a sua aplicação potencial no aumento da vida útil de carne crua. Cubos de carne bovina foram imersos por 5 minutos no sobrenadante filtrado e neutralizado dessa cultura (Tratamento A e mantidos a 5ºC. Contagens de microrganismos psicrotróficos e mesófilos, determinação de pH e de acidez total foram realizadas nas amostras após 0, 3, 6, 9, 12 e 15 dias. Essas determinações foram

  19. Isolation of bacteriocin-producing lactic acid bacteria from meat and meat products and its spectrum of inhibitory activity Isolamento de bactérias lácticas produtoras de bacteriocinas a partir de carnes e produtos cárneos e seu espectro de atividade inibitória

    Directory of Open Access Journals (Sweden)

    Renata Bromberg

    2004-06-01

    Full Text Available A total of 285 samples of meat and meat products were evaluated for the presence of bacteriocin-producing lactic acid bacteria by the "sandwich" test. From 174 of these samples, 813 strains of lactic acid bacteria were isolated. They were able to inhibit the growth of Staphylococcus aureus CTC 33 and/or Listeria innocua Lin 11. When evaluated by the well-diffusion assay, 128 of these strains inhibited the growth of the indicator strains. The inhibitory spectra of activity of the isolates were evaluated against a range of Gram-positive and Gram-negative test organisms. S. aureus was the most sensitive indicator tested, whereas Enterococcus faecalis and Lactobacillus plantarum were the most resistant ones. All the compounds produced by the lactic acid bacteria were fully or partially inactivated by some of the proteolytic enzymes, which indicates their proteinaceous nature. The antimicrobial activity of the bacteriocins produced by the lactic acid bacteria isolated in this work could act as a potential barrier to inhibit the growth of spoilage bacteria and foodborne pathogens.Um total de 285 amostras de carnes e produtos cárneos foi avaliado para detecção de culturas produtoras de bacteriocinas pelo método do "sanduíche". A partir de 174 destas amostras, 813 linhagens de bactérias lácticas com atividade inibitória sobre Staphylococcus aureus CTC 033 e/ou Listeria innocua Lin 11 foram isoladas. Quando examinadas pelo método de antagonismo simultâneo em poços, 128 destas linhagens inibiram o crescimento dos microrganismos indicadores. O espectro de atividade das linhagens isoladas foi avaliado com diversos microrganismos Gram-positivos e Gram-negativos. De um modo geral, S. aureus foi o microrganismo indicador mais sensível, enquanto Enterococcus faecalis e Lactobacillus plantarum foram os mais resistentes. Todos os compostos antimicrobianos produzidos pelas bactérias lácticas testadas foram completa ou parcialmente inativados por

  20. Entrapment of Bacteriocin 105B onto Fabric with Titania

    Science.gov (United States)

    2017-02-09

    information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD-MM...paper towels. The samples were “squeezed” between the paper towels to remove excess water. To bond the ReputexTM to the fabric, the samples were...Nisin: The nisin stock solution was prepared by measuring out 0.125 g of 20% (w/v) nisin and adding it to 25 mL of 25 mM Tris buffer pH 7.5 to give

  1. Development of Purification Protocol Specific for Bacteriocin 105B

    Science.gov (United States)

    2017-02-09

    antimicrobials are employed and the entire bacteria population is not killed. Bacteria that possess resistance genes or have developed resistance to...to combat the resistant pathogenic strains (Knobler et al. 2003). This strategy may provide an opportunity for the bacterial pool to be further...Bacillus anthracis. As the current application of broad-spectrum antimicrobials promotes the development of multi- drug resistant microorganisms

  2. Isolation and characterization of a bacteriocin produced by an ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-19

    Oct 19, 2009 ... The detergents Tween 20, Tween 80 and sodium dodecyl sulfate. (SDS) were used at a final concentration of 1% (v/v), sodium deoxy- cholate was used at 1 mg mL-1 and Triton X-100 was used at 0.02%. (v/v). DL-Dithiothreitol (DTT), ethylenediamine tetraacetic acid. (EDTA) and trichloroacetic acid (TCA) ...

  3. Antimicrobial activities of the bacteriocin-like substances produced ...

    African Journals Online (AJOL)

    A total of 450 different colonies, isolated from 25 samples of dromedary milk collected from Laâyoune region of Morocco, were tested for antimicrobial compounds production. Out of these, 30 were determined to be lactic acid bacteria (LAB) and able to inhibit the growth of the indicator strain Listeria innocua CECT 4030.

  4. Bacteriocins and lactic acid bacteria - a minireview | Savadogo ...

    African Journals Online (AJOL)

    Fermentation of various foods by lactic acid bacteria (LAB) is one of the oldest forms of biopreservation practised by mankind. Bacterial antagonism has been recognized for over a century but in recent years this phenomenon has received more scientific attention, particulary in the use of various strains of lactic acid bacteria.

  5. Bacteriophage and bacteriocin typing scheme for Clostridium difficile.

    OpenAIRE

    Sell, T L; Schaberg, D R; Fekety, F R

    1983-01-01

    The study of the epidemiology of infection with Clostridium difficile would be aided by a way to type individual bacterial isolates. We therefore sought bacteriophages for use in typing. With mitomycin C exposure (3 micrograms/ml), filtrates from 10 strains of C. difficile had plaque-forming lytic activity on other C. difficile strains. Individual phage were passaged and made into high-titer stock preparations for typing. Electron microscopy revealed tailed phage particles from one such prepa...

  6. Antimicrobial activities of the bacteriocin-like substances produced ...

    African Journals Online (AJOL)

    Administrator

    2011-09-07

    Sep 7, 2011 ... activity from hydrogen peroxide was blocked by the addition of a sterile solution of catalase (2619 U/mg. sigma), dissolved in phosphate buffer at pH 7 and 1 .... arginine and esculin, the production of acetoin and CO2 and for growth at 40°C in the presence of 4% NaCl. The characteristics of strain R112 are ...

  7. Partial characterization of a bacteriocin produced by Lactobacillus ...

    African Journals Online (AJOL)

    최학종

    2012-05-15

    May 15, 2012 ... Escherichia coli BL21(DE3) was transformed with a pHCD1 plasmid harboring the human β-defensin-1. (hBD1) gene fused in frame behind a disulfide bond isomerase (DsbC), a His-tag, and an enterokinase cleavage site. After induction, the DsbC-hBD1 was expressed as a ~36 kDa soluble fusion protein ...

  8. Isolation and characterization of a bacteriocin produced by an ...

    African Journals Online (AJOL)

    involved in domestic animal diseases, including Escherichia coli, Salmonella pullorum, Pseudomonas aeruginosa, Pasteurella multocida, Clostridium perfringens, Micrococcus luteus, Streptococcus bovis and Staphylococcus aureus. Two multidrug-resistant clinical isolates and a phytopathogenic yeast strain were also ...

  9. Bacteriocins and lactic acid bacteria - a minireview | Savadogo ...

    African Journals Online (AJOL)

    African Journal of Biotechnology. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 5, No 9 (2006) >. Log in or Register to get access to full text downloads.

  10. Antimicrobial activities of the bacteriocin-like substances produced ...

    African Journals Online (AJOL)

    Administrator

    2011-09-07

    Sep 7, 2011 ... A total of 450 different colonies, isolated from 25 samples of dromedary milk collected from Laâyoune region of Morocco, were tested for antimicrobial compounds production. Out of these, 30 were determined to be lactic acid bacteria (LAB) and able to inhibit the growth of the indicator strain Listeria innocua ...

  11. Competence-Dependent Bacteriocin Production by Streptococcus gordonii DL1 (Challis)▿

    OpenAIRE

    Heng, Nicholas C. K.; Tagg, John R.; Tompkins, Geoffrey R.

    2006-01-01

    The production of streptocins STH1 and STH2 by Streptococcus gordonii DL1 (Challis) is directly controlled by the competence regulon, which requires intact comR and comAB loci. The streptocin (sth) locus comprises two functional genes, sthA and sthB. Whereas STH1 activity requires sthA alone, STH2 activity depends on both genes.

  12. Core-shell PLA-PVA porous microparticles as carriers for bacteriocin nisin.

    Science.gov (United States)

    Holcapkova, Pavlina; Hrabalikova, Martina; Stoplova, Petra; Sedlarik, Vladimir

    2017-05-01

    This work is focused on preparation of novel porous type of core-shell-structured microparticles based on polylactide (shell) and poly(vinyl alcohol) cross-linked with glutaric acid (GA) (core) prepared by water-in-oil-in-water solvent evaporation technique. The microparticle systems were used as delivery systems for immobilisation of model antibacterial agent - nisin. The effect of cross-linking and the initial amount of nisin on their morphology was investigated using scanning electron microscopy, BET analysis, zeta potential measurement and Fourier transform infra-red spectroscopy. Encapsulation efficiency and release profile of nisin from the microparticles were studied by high performance liquid chromatography. Antibacterial activity of the prepared systems was tested by dilution and spread plate technique. Results showed the microparticles in the size range of 9-16 μm in diameter with spherical multi-hollow core-shell structure. The presence of cross-linking agent GA influences the release profile of the peptide and has synergistic effect on Listeria monocytogenes growth reduction.

  13. Phage tal-like (high-molecular-weight) bacteriocins of Budvicia aquatica and Pragia fontium (Enterobacteriaceae)

    Czech Academy of Sciences Publication Activity Database

    Šmarda, J.; Benada, Oldřich

    2005-01-01

    Roč. 71, č. 12 (2005), s. 8970-8973 ISSN 0099-2240 Institutional research plan: CEZ:AV0Z50200510 Keywords : PSEUDOMONAS-AERUGINOSA * GROWTH-INHIBITION * BACTERIOPHAGE Subject RIV: EE - Microbiology, Virology Impact factor: 3.818, year: 2005

  14. Bacteriocins of food grade lactic acid bacteria in hurdle technology for milk and dairy

    Science.gov (United States)

    The use of high temperature/short time (HTST) pasteurization has proven effective in eliminating microbial contaminants from raw milk; however some thermoduric bacteria and spore-formers have been reported to survive pasteurization at low numbers. Furthermore, improper pasteurization, post-pasteuri...

  15. Lyophilized Carnobacterium divergens AS7 bacteriocin preparation improves performance of broiler chickens challenged with Clostridium perfringens

    DEFF Research Database (Denmark)

    Jozefiak, D; Sip, A; Rutkowski, A

    2012-01-01

    isolates. In total, 480 one-day-old male Ross 308 chicks were randomly assigned to 4 experimental groups (12 replicate pens of 10 birds per treatment). The diets were either nonsupplemented or supplemented with a lyophilized preparation of divercin AS7. On d 18, 19, and 20, half of the birds were...

  16. Bet-hedging in bacteriocin producing Escherichia coli populations: the single cell perspective

    Science.gov (United States)

    Bayramoglu, Bihter; Toubiana, David; van Vliet, Simon; Inglis, R. Fredrik; Shnerb, Nadav; Gillor, Osnat

    2017-02-01

    Production of public goods in biological systems is often a collaborative effort that may be detrimental to the producers. It is therefore sustainable only if a small fraction of the population shoulders the cost while the majority reap the benefits. We modelled this scenario using Escherichia coli populations producing colicins, an antibiotic that kills producer cells’ close relatives. Colicin expression is a costly trait, and it has been proposed that only a small fraction of the population actively expresses the antibiotic. Colicinogenic populations were followed at the single-cell level using time-lapse microscopy, and showed two distinct, albeit dynamic, subpopulations: the majority silenced colicin expression, while a small fraction of elongated, slow-growing cells formed colicin-expressing hotspots, placing a significant burden on expressers. Moreover, monitoring lineages of individual colicinogenic cells showed stochastic switching between expressers and non-expressers. Hence, colicin expressers may be engaged in risk-reducing strategies—or bet-hedging—as they balance the cost of colicin production with the need to repel competitors. To test the bet-hedging strategy in colicin-mediated interactions, competitions between colicin-sensitive and producer cells were simulated using a numerical model, demonstrating a finely balanced expression range that is essential to sustaining the colicinogenic population.

  17. Functional analysis of circular and linear bacteriocins of Gram-positive bacteria

    NARCIS (Netherlands)

    Kemperman, Robèr Antoine

    2005-01-01

    SUMMARY & GENERAL DISCUSSION Preservation methods such as drying and fermenting to store food products for longer periods of time have been used for centuries. Nowadays, people desire fresh and minimally processed food, to be prepared with minimal cooking. This sets new targets for the food

  18. CHAPTER TWO

    African Journals Online (AJOL)

    User

    antimicrobial agents include organic acids, hydrogen peroxide, diacetyls and bacteriocin. Bacteriocins are antimicrobial peptides or small protein complex displaying bactericidal activity against food spoilage and food pathogenic organisms. Bacteriocin are ribosomally synthesized peptides produced by various bacteria ...

  19. Elongated cells of Listeria monocytogenes in biofilms in the presence of sucrose and bacteriocin-producing Leuconostoc mesenteroides A11

    Directory of Open Access Journals (Sweden)

    Regiane Priscilla Ratti

    2010-12-01

    Full Text Available Listeria monocytogenes is a foodborne pathogen which may survive in biofilms and persist in food processing plants. In this study, the ability of Leuconostoc mesenteroides (bac+ and bac- to inhibit biofilm formation by L. monocytogenes ATCC 19115 was studied with stainless steel coupons immersed in BHI broth and BHI broth plus sucrose in combination with the Lactic Acid Bacteria (LAB. Adhered cells were collected with swabs and enumerated on selective agars (Oxford for listeria and MRS for leuconostoc. Leuconostoc mesenteroides bac+ in co-culture with L. monocytogenes was effective to inhibit biofilm formation by listeria for up to 3 hours of incubation, but at 24 hours, biofilm was present in all conditions tested, as confirmed by observations of stainless steel coupons under Scanning Electron Microscopy (SEM. It was also observed that in the presence of L. mesenteroides bac+ in BHI plus sucrose, a high number of elongated cells of L. monocytogenes was present, which may indicate an adaptation response of the pathogen to stress conditions with important implications for food safety.

  20. BACTERIOCIN E1073 PRODUCED BY ENTEROCOCCUS FAECIUM LWP1073 IS EFFECTIVE FOR TREATING COMMENSAL CLOSTRIDIUM PERFRINGENS INFECTION IN BROILERS

    Science.gov (United States)

    Enterotoxin-producing Clostridium perfringens type A bacteria occupy a significant place in the etiological structure of food-borne infections in humans. One potential approach to minimize infections associated with food-borne pathogens is to control the carriage of C. perfringens in broilers. For ...

  1. Tn6350, a Novel Transposon Carrying Pyocin S8 Genes Encoding a Bacteriocin with Activity against Carbapenemase-Producing Pseudomonas aeruginosa.

    Science.gov (United States)

    Turano, Helena; Gomes, Fernando; Barros-Carvalho, Gesiele A; Lopes, Ralf; Cerdeira, Louise; Netto, Luis E S; Gales, Ana C; Lincopan, Nilton

    2017-05-01

    A novel transposon belonging to the Tn 3 -like family was identified on the chromosome of a commensal strain of Pseudomonas aeruginosa sequence type 2343 (ET02). Tn 6350 is 7,367 bp long and harbors eight open reading frames (ORFs), an ATPase (IS 481 family), a transposase (DDE catalytic type), a Tn 3 resolvase, three hypothetical proteins, and genes encoding the new pyocin S8 with its immunity protein. We show that pyocin S8 displays activity against carbapenemase-producing P. aeruginosa , including IMP-1, SPM-1, VIM-1, GES-5, and KPC-2 producers. Copyright © 2017 American Society for Microbiology.

  2. Effect of bacteriocin-producing lactobacilli on the survival of Escherichia coli and Listeria in a dynamic model of the stomach and the small intestine

    NARCIS (Netherlands)

    Gänzle, M.G.; Hertel, C.; Vossen, J.M.B.M. van der; Hammes, W.P.

    1999-01-01

    The survival of Lactobacillus curvatus LTH 1174 (bac+) and (bac-) in combination with Escherichia coli LTH 1600 or Listeria innocua DSM20649 during transit through a dynamic model of the human stomach and small intestine (GIT model) was studied. Furthermore, we determined the digestion of curvacin A

  3. Co-production of surfactin and a novel bacteriocin by Bacillus subtilis subsp. subtilis H4 isolated from bikalga, an African alkaline Hibiscus sabdariffa seed fermented condiment

    DEFF Research Database (Denmark)

    Compaore, C. S.; Nielsen, Dennis S.; Ouoba, L. I. I.

    2013-01-01

    Bikalga is a Hibiscus sabdariffa seed fermented condiment widely consumed in Burkina Faso and neighboring countries. The fermentation is dominated by Bacillus subtilis group species. Ten B. subtilis subsp. subtilis (six isolates) and Bacillus licheniformis (four isolates) isolated from traditional...... and Bacillus cereus, while CFS of 2 B. licheniformis (E3 and F9) strains only inhibited M. luteus. The antimicrobial substance(s) produced by B. subtilis subsp. subtilis H4 was further characterized. The antimicrobial substance(s) produced by H4 was detected from mid-exponential growth phase. The activity...... bikalga were examined for their antimicrobial activity against a panel of 36 indicator organisms including Gram-positive and Gram-negative bacteria and yeasts. The Bacillus spp. isolates showed variable inhibitory abilities depending on the method used. Both Gram-positive and Gram-negative bacteria were...

  4. Screening of malting sorghum samples for lactic acid bacteria with ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-06-17

    Jun 17, 2009 ... fermentum and Lactobacillus acidophilus, respectively. LAB isolated from three varieties of sorghum grains undergoing malting exhibited the ability to produce bacteriocin and hydrogen peroxide. Key words: Lactic acid bacteria, sorghum varieties, malting, bacteriocin, hydrogen peroxide. INTRODUCTION.

  5. Les bactériocines des bactéries lactiques : caractéristiques et intérêts pour la bioconservation des produits alimentaires

    OpenAIRE

    Dortu C.; Thonart P.

    2009-01-01

    Bacteriocins from lactic acid bacteria: interest for food products biopreservation. Bacteriocins from lactic acid bacteria are low molecular weight antimicrobial peptides. They have inhibitory activity against the bacteria that are closed related to the producer strains and a narrow inhibitory spectrum. Nevertheless, most of them have activity against some food-born pathogenic bacteria as Listeria monocytogenes. The application of bacteriocins or bacteriocin producing lactic acid bacteria in ...

  6. Genome Exploitation and Bioinformatics Tools

    Science.gov (United States)

    de Jong, Anne; van Heel, Auke J.; Kuipers, Oscar P.

    Bioinformatic tools can greatly improve the efficiency of bacteriocin screening efforts by limiting the amount of strains. Different classes of bacteriocins can be detected in genomes by looking at different features. Finding small bacteriocins can be especially challenging due to low homology and because small open reading frames (ORFs) are often omitted from annotations. In this chapter, several bioinformatic tools/strategies to identify bacteriocins in genomes are discussed.

  7. Co-expression of Nisin Z and Leucocin C as a Basis for Effective Protection Againstin Pasteurized Milk

    NARCIS (Netherlands)

    Fu, Yuxin; Mu, Dongdong; Qiao, Wanjin; Zhu, Duolong; Wang, Xiangxiang; Liu, Fulu; Xu, Haijin; Saris, Per; Kuipers, Oscar P; Qiao, Mingqiang

    2018-01-01

    Nisin, an important bacteriocin fromLactococcus lactissubsp., is primarily active against various Gram-positive bacteria. Leucocin C, produced byLeuconostoc carnosum4010, is a class IIa bacteriocin used to inhibit the growth ofListeria monocytogenes.Because two bacteriocins have different modes of

  8. Purification, Characterization and Antibacterial Mechanism of ...

    African Journals Online (AJOL)

    Purpose: To carry out the extraction, purification and biological characterization, and assess the antibacterial activity of bacteriocin from Lactobacillus acidophilus XH1. Methods: Chloroform extraction method was used for bacteriocin extraction while characterization of bacteriocin was carried out by flat-dug well agar ...

  9. Les bactériocines des bactéries lactiques : caractéristiques et intérêts pour la bioconservation des produits alimentaires

    Directory of Open Access Journals (Sweden)

    Dortu C.

    2009-01-01

    Full Text Available Bacteriocins from lactic acid bacteria: interest for food products biopreservation. Bacteriocins from lactic acid bacteria are low molecular weight antimicrobial peptides. They have inhibitory activity against the bacteria that are closed related to the producer strains and a narrow inhibitory spectrum. Nevertheless, most of them have activity against some food-born pathogenic bacteria as Listeria monocytogenes. The application of bacteriocins or bacteriocin producing lactic acid bacteria in food products to inhibit pathogenic or food-spoilage bacteria has then been suggested. This review focuses on the classification, structure, function, mode of action, biosynthesis and current food applications of bacteriocins from lactic acid bacteria.

  10. A Multibacteriocin Cheese Starter System, Comprising Nisin and Lacticin 3147 in Lactococcus lactis, in Combination with Plantaricin from Lactobacillus plantarum.

    Science.gov (United States)

    Mills, S; Griffin, C; O'Connor, P M; Serrano, L M; Meijer, W C; Hill, C; Ross, R P

    2017-07-15

    Functional starter cultures demonstrating superior technological and food safety properties are advantageous to the food fermentation industry. We evaluated the efficacies of single- and double-bacteriocin-producing starters of Lactococcus lactis capable of producing the class I bacteriocins nisin A and/or lacticin 3147 in terms of starter performance. Single producers were generated by mobilizing the conjugative bacteriophage resistance plasmid pMRC01, carrying lacticin genetic determinants, or the conjugative transposon Tn 5276 , carrying nisin genetic determinants, to the commercial starter L. lactis CSK2775. The effect of bacteriocin coproduction was examined by superimposing pMRC01 into the newly constructed nisin transconjugant. Transconjugants were improved with regard to antimicrobial activity and bacteriophage insensitivity compared to the recipient strain, and the double producer was immune to both bacteriocins. Bacteriocin production in the starter was stable, although the recipient strain proved to be a more efficient acidifier than transconjugant derivatives. Overall, combinations of class I bacteriocins (the double producer or a combination of single producers) proved to be as effective as individual bacteriocins for controlling Listeria innocua growth in laboratory-scale cheeses. However, using the double producer in combination with the class II bacteriocin producer Lactobacillus plantarum or using the lacticin producer with the class II producer proved to be most effective for reducing bacterial load. As emergence of bacteriocin tolerance was reduced 10-fold in the presence of nisin and lacticin, we suggest that the double producer in conjunction with the class II producer could serve as a protective culture providing a food-grade, multihurdle approach to control pathogenic growth in a variety of industrial applications. IMPORTANCE We generated a suite of single- and double-bacteriocin-producing starter cultures capable of generating the class I

  11. Caractérisation d'une bactériocine produite par une bactérie lactique Leuconostoc pseudomesenteroides isolée du boza

    OpenAIRE

    Makhloufi, Kahina Maya

    2011-01-01

    Lactic acid bacteria inhibit food spoilage bacteria by producing large amounts of lactic acid and growth-inhibiting peptides termed bacteriocins. Bacteriocins are ribosomally synthesized and are usually active against related species including pathogens, in particular Listeria and Enterococcus. We here isolated a bacteriocin produced by a strain called KM432Bz isolated from boza, a fermented drink usually consummed in Balkans, that we identified as a Leuconostoc pseudomesenteroides. Mass spec...

  12. In-situ inhibition of Staphylococcus aureus by lactic acid bacteria consortia from two traditional Slovenian raw milk cheeses

    Directory of Open Access Journals (Sweden)

    Aljoša Trmčić

    2010-09-01

    Full Text Available Bacteriocin(s producing lactic acid bacteria naturally present in traditional cheeses represent an inexhaustive pool of microbes with safeguarding potential. Some bacteriocins produced by cheese lactic acid bacteria were already described as successful anti-staphylococcal agents. The presence of genes for bacteriocins with potential anti-staphylococcal activity was also demonstrated in two Slovenian traditional raw milk cheeses, “Tolminc” and “Kraški ovčji sir”. Same bacteriocin genes were also detected in viable lactic acid bacteria consortia’s isolated from “bacteriocin positive cheeses” on Rogosa, M17 and CATC agar media. The aim of the research was to elucidate whether or not this particular cheese consortia, in which bacteriocin genes were detected, actually exhibit anti-staphylococcal activity in milk and/or cheese. For this purpose different cheese consortia were selected in relation to versatility of detected bacteriocin genes and used to perform challenge tests against Staphylococcus aureus in milk and cheese. In milk following the time/temperature regime of traditional cheese production all cheese consortia effectively inhibited growth of Staphylococcus aureus in the range of app. 2 to 3 log. In cheese the inhibition of staphylococci was less pronounced but still evident since inhibition of app. 1.5 log was detected. Sole inhibition by lactic acid production was ruled out whilelinking inhibition directly to bacteriocin production would take some additional work.

  13. Common occurrence of antibacterial agents in human intestinal microbiota

    Directory of Open Access Journals (Sweden)

    Fatima eDrissi

    2015-05-01

    Full Text Available Laboratory experiments have revealed many active mechanisms by which bacteria can inhibit the growth of other organisms. Bacteriocins are a diverse group of natural ribosomally-synthesized antimicrobial peptides produced by a wide range of bacteria and which seem to play an important role in mediating competition within bacterial communities. In this study, we have identified and established the structural classification of putative bacteriocins encoded by 317 microbial genomes in the human intestine. On the basis of homologies to available bacteriocin sequences, mainly from lactic acid bacteria, we report the widespread occurrence of bacteriocins across the gut microbiota: 175 bacteriocins were found to be encoded in Firmicutes, 79 in Proteobacteria, 34 in Bacteroidetes and 25 in Actinobacteria. Bacteriocins from gut bacteria displayed wide differences among phyla with regard to class distribution, net positive charge, hydrophobicity and secondary structure, but the α-helix was the most abundant structure. The peptide structures and physiochemical properties of bacteriocins produced by the most abundant bacteria in the gut, the Firmicutes and the Bacteroidetes, seem to ensure low antibiotic activity and participate in permanent intestinal host defence against the proliferation of harmful bacteria. Meanwhile, the potentially harmful bacteria, including the Proteobacteria, displayed highly effective bacteriocins, probably supporting the virulent character of diseases. These findings highlight the eventual role played by bacteriocins in gut microbial competition and their potential place in antibiotic therapy.

  14. Protection of honeybee Apis mellifera by its endogenous and exogenous lactic flora against bacterial infections

    Directory of Open Access Journals (Sweden)

    Irakli Janashia

    2016-09-01

    Three exogenous bacteriocin-producing LAB strains were tested against the same pathogens and against 25 endogenous bacterial isolates representing 11 different LAB species. The screening showed that all the tested exogenous bacteriocin-producing strains inhibited the tested P. larvae strains. The endogenous LAB strains exhibited varied sensitivity profiles when treated with bacteriocin-producing strains. This raises similar challenges to those observed in antibiotic applications leading to dysbacteriosis, even though the efficacy of these bacteriocins against P. larvae in an in vitro system is evident.

  15. ef1097 and ypkK encode enterococcin V583 and corynicin JK, members of a new family of antimicrobial proteins (bacteriocins) with modular structure from Gram-positive bacteria.

    Science.gov (United States)

    Swe, Pearl M; Heng, Nicholas C K; Ting, Yi-Tian; Baird, Hayley J; Carne, Alan; Tauch, Andreas; Tagg, John R; Jack, Ralph W

    2007-10-01

    Unlike the colicins, microcins and related peptide antibiotics, little is known about antibiotic proteins (M(r)>10,000) from Gram-positive bacteria, since only few examples have been described to date. In this study we used heterologous expression of recombinant proteins to access the 17 kDa antibiotic protein SA-M57 from Streptococcus pyogenes, along with two proteins of unknown function identified in publicly available databases: EF1097 from Enterococcus faecalis and YpkK from Corynebacterium jeikeium. Here we show that all three are antibiotic proteins with different spectra of antimicrobial activity that kill sensitive bacteria at nanomolar concentrations. In silico structure predictions indicate that although the three proteins share little sequence similarity, they may be composed of conserved secondary structural elements: a relatively unstructured, acidic N-terminal portion and a basic C-terminal portion characterized by two helical elements separated by a loop structure and stabilized by an essential disulphide. Expression of individual segments as well as protein chimaeras revealed that, at least in the case of YpkK, the C-terminal portion is responsible for the killing action of the protein, whereas the role of the N-terminal portion remains unclear. Both scnM57 and ef1097 appear to be widely distributed in Strep. pyogenes and Ent. faecalis (respectively), whereas ypkK is found only rarely amongst clinical isolates of C. jeikeium. Finally, we determined that the proteins kill sensitive bacteria without lysis, a feature that distinguishes them from known murolytic proteins.

  16. Manihot esculenta Crantz

    African Journals Online (AJOL)

    Owner

    brevis, L. acidophilus and Bacillus subtilis inhibited the growth of E. coli and Staphylococcus aureus. Inhibition of the pathogenic microorganisms was probably due to the production of organic acids and bacteriocins. Key words: Cassava product microflora, antagonism, bacteriocins, organic acids. INTRODUCTION.

  17. Bacteriocinogenic potential of a probiotic strain Bacillus coagulans [BDU3] from Ngari.

    Science.gov (United States)

    Abdhul, Kaja; Ganesh, Mohan; Shanmughapriya, Santhanam; Vanithamani, Shanmugam; Kanagavel, Murugesan; Anbarasu, Kumarasamy; Natarajaseenivasan, Kalimuthusamy

    2015-08-01

    Bacteriocin producing strain BDU3 was isolated from a traditional fermented fish of Manipur Ngari. The strain BDU3 was identified as Bacillus coagulans by phenotypic and genotypic characterization. The BDU3 produced novel bacteriocin, which showed an antimicrobial spectrum toward a wide spectrum of food borne, and closely related pathogens with a MIC that ranged between 0.5 and 2.5 μg/mL. The isolate was able to tolerate pH as low as 2.0 and up to 0.2% bile salt concentration. Three step purification was employed to increase the specific activity of the antimicrobial compound. The fractions were further chromatographed by Rp-HPLC C-18 column and the purified bacteriocin had a specific activity of ∼8500 AU/mg. However, the potency of bacteriocin was susceptible to digestion with Proteinase K, Pepsin, SDS, EDTA and Urea. Molecular mass of purified bacteriocin was found to be 1.4 kDa using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF). The functional group was revealed by FTIR analysis. The cytotoxicity assay (MTT) using purified bacteriocin showed 2 times lower EC50 values compared to SDS. This is the smaller bacteriocin ever reported before from B. coagulans with greater antimicrobial potency with lower cytotoxicity. This bacteriocin raises the possibilities to be used as a biopreservative in food industries. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. De novo structural modeling and computational sequence analysis ...

    African Journals Online (AJOL)

    Bacteriocins produced by different groups of bacteria are ribosomally synthesized peptides or proteins with antimicrobial and specific antagonistic bacterial interaction activity. Rhizobium leguminosarum is a Gram-negative soil bacterium which plays an important role in nitrogen fixation in leguminose plants. Bacteriocins ...

  19. Genetic analysis of a novel plasmid encoded durancin locus in Enterococcus durans 41D

    Science.gov (United States)

    Enterococcus durans is commonly found in the intestinal tract in humans and animals and several strains are known to produce bacteriocins. Durancin GL, a novel bacteriocin of Enterococcus durans 41D with antilisterial activity was isolated from artisanal cheese samples and its genetic determinants ...

  20. Inhibitory activity of Lactobacillus curvatus CWBI-B28 against ...

    African Journals Online (AJOL)

    user

    2006-11-16

    Nov 16, 2006 ... A bacteriocin-producing strain of Lactobacillus curvatus CWBI-B28 isolated from raw meat was shown to inhibit Listeria monocytogenes and pathogenic strains of Escherichia coli by the well diffusion assay. To confirm whether the bacteriocin was involved in E. coli O157 inhibition, growth of the pathogen ...

  1. Food Applications and Regulation

    Science.gov (United States)

    Gálvez, Antonio; Abriouel, Hikmate; Omar, Nabil Ben; Lucas, Rosario

    This chapter deals with food applications of bacteriocins. Regulatory issues on the different possibilities for incorporating bacteriocins as bioprotectants are discussed. Specific applications of bacteriocins or bacteriocin-producing strains are described for main food categories, including milk and dairy products, raw meats, ready-to-eat meat and poultry products, fermented meats, fish and fish products or fermented fish. The last section of the chapter deals with applications in foods and beverages derived from plant materials, such as raw vegetable foods, fruits and fruit juices, cooked food products, fermented vegetable foods and ­fermented beverages. Results obtained for application of bacteriocins in combination with other hurdles are also discussed for each specific case, with a special emphasis on novel food packaging and food-processing technologies, such as irradiation, pulsed electric field treatments or high hydrostatic pressure treatment.

  2. Antibacterial Activity of Some Lactic Acid Bacteria Isolated from an Algerian Dairy Product

    Directory of Open Access Journals (Sweden)

    Abdelkader Mezaini

    2009-01-01

    Full Text Available In the present study, the antibacterial effect of 20 lactic acid bacteria isolates from a traditional cheese was investigated. 6 isolates showed antibacterial effect against Gram positive bacteria. Streptococcus thermophilus T2 strain showed the wide inhibitory spectrum against the Gram positive bacteria. Growth and bacteriocin production profiles showed that the maximal bacteriocin production, by S. thermophilus T2 cells, was measured by the end of the late-log phase (90 AU ml−1 with a bacteriocine production rate of 9.3 (AU ml−1 h−1. In addition, our findings showed that the bacteriocin, produced by S. thermophilus T2, was stable over a wide pH range (4–8; this indicates that such bacteriocin may be useful in acidic as well as nonacidic food. This preliminarily work shows the potential application of autochthonous lactic acid bacteria to improve safety of traditional fermented food.

  3. Characterization of lactococci isolated from homemade kefir

    Directory of Open Access Journals (Sweden)

    Kojić M.

    2007-01-01

    Full Text Available Five bacteriocin-producing lactococci isolates from traditionally prepared kefir were determined as Lactococcus lactis subsp. lactis. The analyzed isolates showed different plasmid profiles and no cross inhibition between them was detected. Moreover, natural isolate BGKF26 was resistant to the antimicrobial activity of nisin producing strain NP45. Plasmid curing experiments revealed that the genes encoding bacteriocin and proteinase production are located on separate genetic elements, except in BGKF26. Production of the tested bacteriocins depends on the concentration of casitone or triptone in the medium. Higher concentrations of casitone or triptone induce bacteriocin activity. Our DNA-DNA hybridization analyses suggest that the analyzed antimicrobial compounds probably are lactococcin-like bacteriocins.

  4. Assessment of the Bacteriocinogenic Potential of Marine Bacteria Reveals Lichenicidin Production by Seaweed-Derived Bacillus spp.

    Directory of Open Access Journals (Sweden)

    Gillian E. Gardiner

    2012-10-01

    Full Text Available The objectives of this study were (1 to assess the bacteriocinogenic potential of bacteria derived mainly from seaweed, but also sand and seawater, (2 to identify at least some of the bacteriocins produced, if any and (3 to determine if they are unique to the marine environment and/or novel. Fifteen Bacillus licheniformis or pumilus isolates with antimicrobial activity against at least one of the indicator bacteria used were recovered. Some, at least, of the antimicrobials produced were bacteriocins, as they were proteinaceous and the producers displayed immunity. Screening with PCR primers for known Bacillus bacteriocins revealed that three seaweed-derived Bacillus licheniformis harbored the bli04127 gene which encodes one of the peptides of the two-peptide lantibiotic lichenicidin. Production of both lichenicidin peptides was then confirmed by mass spectrometry. This is the first definitive proof of bacteriocin production by seaweed-derived bacteria. The authors acknowledge that the bacteriocin produced has previously been discovered and is not unique to the marine environment. However, the other marine isolates likely produce novel bacteriocins, as none harboured genes for known Bacillus bacteriocins.

  5. 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.

  6. The ColM Family, Polymorphic Toxins Breaching the Bacterial Cell Wall

    Directory of Open Access Journals (Sweden)

    Maarten G. K. Ghequire

    2018-02-01

    Full Text Available Bacteria host an arsenal of antagonism-mediating molecules to combat for ecologic space. Bacteriocins represent a pivotal group of secreted antibacterial peptides and proteins assisting in this fight, mainly eliminating relatives. Colicin M, a model for peptidoglycan-interfering bacteriocins in Gram-negative bacteria, appears to be part of a set of polymorphic toxins equipped with such a catalytic domain (ColM targeting lipid II. Diversifying recombination has enabled parasitism of different receptors and has also given rise to hybrid bacteriocins in which ColM is associated with another toxin module. Remarkably, ColM toxins have recruited a diverse array of immunity partners, comprising cytoplasmic membrane-associated proteins with different topologies. Together, these findings suggest that different immunity mechanisms have evolved for ColM, in contrast to bacteriocins with nuclease activities.

  7. Inactivation of Geobacillus stearothermophilus in canned food and coconut milk samples by addition of enterocin AS-48.

    Science.gov (United States)

    Viedma, Pilar Martínez; Abriouel, Hikmate; Ben Omar, Nabil; López, Rosario Lucas; Valdivia, Eva; Gálvez, Antonio

    2009-05-01

    The cyclic bacteriocin enterocin AS-48 was tested on a cocktail of two Geobacillus stearothermophilus strains in canned food samples (corn and peas), and in coconut milk. AS-48 (7 microg/g) reduced viable cell counts below detection levels in samples from canned corn and peas stored at 45 degrees C for 30 days. In coconut milk, bacterial inactivation by AS-48 (1.75 microg/ml) was even faster. In all canned food and drink samples inoculated with intact G. stearothermophilus endospores, bacteriocin addition (1.75 microg per g or ml of food sample) rapidly reduced viable cell counts below detection levels and avoided regrowth during storage. After a short-time bacteriocin treatment of endospores, trypsin addition markedly increased G. stearothermophilus survival, supporting the effect of residual bacteriocin on the observed loss of viability for endospores. Results from this study support the potential of enterocin AS-48 as a biopreservative against G. stearothermophilus.

  8. Draft Genome Sequence of Leuconostoc mesenteroides 406 Isolated from the Traditional Fermented Mare Milk Airag in Tuv Aimag, Mongolia.

    Science.gov (United States)

    Morita, Hidetoshi; Toh, Hidehiro; Oshima, Kenshiro; Nakano, Akiyo; Hano, Chihiro; Yoshida, Saki; Nguyen, Tien Thi Thuy; Wulijideligen; Tashiro, Kosuke; Arakawa, Kensuke; Miyamoto, Taku

    2016-03-24

    Leuconostoc mesenteroides406 was isolated from the traditional fermented mare milk airag in Tuv Aimag, Mongolia. This strain produces an antilisterial bacteriocin. Here, we report the draft genome sequence of this organism. Copyright © 2016 Morita et al.

  9. Shelf-Life and Safety Enhancement of Processed Meat by Hydrostatic Pressure in Combination with Moderate Temperature and Biopreservatives, Phase IV

    National Research Council Canada - National Science Library

    Kalchayanand, Norasak

    1998-01-01

    .... Roast beef and fermented summer sausage were inoculated with 10(3) to 10(4) cells/g of four pathogens and four spoilage bacteria along with pediocin AcH or one of two bacteriocin-based biopreservatives...

  10. Enterocin from Enterococcus faecium isolated from mangrove ...

    African Journals Online (AJOL)

    Enterococcus faecium isolated from mangrove environment produced enterocin and it showed broad inhibitory spectrum against gram positive and gram negative bacteria such as Lactobacillus plantarum, Enterococcus facealis, Listeria monocytogens and Salmonella paratyphii. The optimum production of bacteriocin ...

  11. Generation of Food-Grade Lactococcal Starters Which Produce the Lantibiotics Lacticin 3147 and Lacticin 481

    Science.gov (United States)

    O'Sullivan, Lisa; Ryan, Maire P.; Ross, R. Paul; Hill, Colin

    2003-01-01

    Transconjugant lactococcal starters which produce both lantibiotics lacticin 3147 and lacticin 481 were generated via conjugation of large bacteriocin-encoding plasmids. A representative of one of the resultant strains proved more effective at killing Lactobacillus fermentum and inhibiting the growth of Listeria monocytogenes LO28H than either of the single bacteriocin-producing parental strains, demonstrating the potential of these transconjugants as protection cultures for food safety applications. PMID:12788782

  12. In situ control of food spoilage fungus using Lactobacillus acidophilus NCDC 291

    OpenAIRE

    Garcha, Seema; Natt, Navdeep Kaur

    2011-01-01

    A challenge for food industry today is to produce minimally processed food, without use of chemical preservatives and little compromise on nutritional status. Lactobacillus acidophilus NCDC 291 can be directly added to food where it enhances shelf life by competing with other microflora (both bacterial and fungal) for food and also by production of antimicrobial metabolites as bacteriocins. Comprehensive studies have demonstrated the in vitro activity of bacteriocins. However their role in pr...

  13. CHARACTERIZATION OF THE PARTIALLY PURIFIED PLANTARCIN SR18 PRODUCED BY LACTOBACILLUS PLANTARUM SR18

    Directory of Open Access Journals (Sweden)

    Wagih El-Shouny

    2013-04-01

    Full Text Available The bacteriocin bound to the cells and that secreted into the culture filtrate of Lactobacillus plantarum SR18 were precipitated by 75% ammomium sulphate, dialysed and further purified by Gel filtration on Sephadex G-100. Bacteriocins were purified from proteins bound to the cell of L. plantarum SR18 (plantarcin SR18 a and culture filtrate proteins (plantarcin SR18 b, respectively. The SDS-PAGE of partially purified Plantarcin SR18a showed a molecular weight of 3.5 KDa. While, plantarcin SR18 b had a molecular weight of 10.3 KDa. The antibacterial activity of the tested plantarcin SR18 preparations suffered no measurable loss after 45 min at 80ºC. Whereas, At 100ºC, significant decrease in the activity of bacteriocin preparations (60- 80 % took place by the end of 45 min. At pH ranged from 5-8, the activity of the plantarcin SR18 preparations suffered no measurable loss. Dissociating agents significantly affected the bacteriocin activity. Thus, tween 80 and mercaptoethanol increased the activity of bacteriocin preparations to 1.2-1.4 fold. Sodium dodecyl sulphate (SDS increased the activity of the tested bacteriocin preparations by about 20%.The lowest residual activity (60% was recorded after treatment with Triton X100 for 45 min. Protease completely inhibited the activities of all forms of plantarcin SR18 after 45 min at 37ºC.

  14. Recent approaches in food bio-preservation - a review

    Directory of Open Access Journals (Sweden)

    Veer Pal Singh

    2018-03-01

    Full Text Available Bio-preservation is a technique of extending the shelf life of food by using natural or controlled microbiota or antimicrobials. The fermentation products as well as beneficial bacteria are generally selected in this process to control spoilage and render pathogen inactive. The special interest organism or central organism used for this purpose is lactic acid bacteria (LAB and their metabolites. They are capable to exhibit antimicrobial properties and helpful in imparting unique flavour and texture to the food products. The major compounds produced by LAB are bacteriocin, organic acids and hydrogen peroxide. Bacteriocin is peptides or proteins with antimicrobial activity. On the basis of size, structure and post-translational modification, bacteriocin is divided into four different classes. Due to non-toxic, non-immunogenic, thermo-resistance characteristics and broad bactericidal activity, LAB bacteriocins are considered good bio-preservative agents. The most common LAB bactriocin is nisin which has wider applications in food industry and has been Food and Drug Administration (FDA approved. Nisin and other bacteriocin are being used in vegetables products, dairy and meat industries. Apart from LAB metabolites, bacteriophages and endolysins has promising role in food processing, preservation and safety. Bacteriocins and endolysins are more suitable for DNA shuffling and protein engineering to generate highly potent variants with expanded activity spectrum. Genetically modified bacteriophages may also be helpful in bio-preservation, however; their safety issues must be addressed properly before selection as bio-preservative agent.

  15. Inactivation of exopolysaccharide and 3-hydroxypropionaldehyde-producing lactic acid bacteria in apple juice and apple cider by enterocin AS-48.

    Science.gov (United States)

    Martínez-Viedma, Pilar; Abriouel, Hikmate; Omar, Nabil Ben; Valdivia, Eva; López, Rosario Lucas; Gálvez, Antonio

    2008-03-01

    The bacteriocin enterocin AS-48 was tested against exopolysaccharide producing lactic acid bacteria (LAB) strains of Lactobacillus collinoides, Lactobacillus dioliovorans and Pediococcus parvulus as well as two 3-hydroxypropionaldehyde (3-HPA)-producing Lb. collinoides strains causing apple cider spoilage. In fresh-made apple juice, a bacteriocin concentration of 2.5 microg/ml reduced the LAB viable cell counts below detection levels during the course of incubation at 10 and 22 degrees C for most strains tested, except for Lb. collinoides 5 and Lb. dioliovorans 29. These two strains were significantly inhibited at 10 degrees C by 5 microg/ml AS-48 or completely inactivated at 22 degrees C. In a commercial Basque apple cider, the added bacteriocin (2.5 microg/ml for Lb. collinoides strains 9 and 10, and 5 microg/ml for the rest of strains) completely inactivated all LAB strains tested during storage at 10 as well as 22 degrees C. In the commercial Asturian apple cider tested the LAB strains showed a poor capacity for survival, but the added bacteriocin was equally effective in reducing the numbers of survivors. When a cocktail of the five LAB strains was tested in commercial Basque apple cider, viable cell counts were reduced below detection levels after 2 days for a bacteriocin concentration of 12.5 microg/ml regardless of storage temperature. Comparison of RAPD-PCR profiles revealed that strain Lb. dioliovorans 29 was always the predominant survivor detected in bacteriocin-treated samples.

  16. Competitive advantage of bacteriocinogenic strains within lactic acid bacteria consortium of raw milk cheese

    Directory of Open Access Journals (Sweden)

    Irena Rogelj

    2011-03-01

    Full Text Available The presence of gene determinants for different bacteriocins has been already demonstrated in traditional Slovenian types of raw milk cheeses ‘Tolminc’ and ‘Kraški’. These genes were present also in the cultivable microbiota. In this research the aim was to establish how the presence of gene determinants for bacteriocins in microbial consortia is reflected in its antimicrobial activity. In addition, one of the goals was to determine whether the strains that carry gene determinants for bacteriocins have any competitive growth advantage in microbial population. Microbial consortium of ‘Tolminc’ cheese was propagated in milk and examined at the end of propagation its antimicrobial activity and the presence of gene determinants for bacteriocins. Comparison of the results obtained before and after propagation leaded to the conclusion that most of the strains possessing gene determinants for bacteriocins were unable to persist during propagation. The strains which did persist during propagation carried gene determinants for enterocins P, L50B and cytolysin. Antimicrobial activity of consortium before and after propagation was not substantially different and cannot be attributed to any of detected bacteriocins.

  17. Control of Listeria monocytogenes in fresh cheese using protective lactic acid bacteria.

    Science.gov (United States)

    Coelho, M C; Silva, C C G; Ribeiro, S C; Dapkevicius, M L N E; Rosa, H J D

    2014-11-17

    In the past years, there has been a particular focus on the application of bacteriocins produced by lactic acid bacteria (LAB) in controlling the growth of pathogenic bacteria in foods. The aim of this study was to select LAB strains with antimicrobial activity, previously isolated from a traditional Azorean artisanal cheese (Pico cheese), in order to identify those with the greatest potential in reducing Listeria monocytogenes in fresh cheese. Eight bacteriocin producer strains identified as Lactococcus lactis (1) and Enterococcus faecalis (7) were tested. In general, the bacteriocin-producing strains presented a moderate growth in fresh cheese at refrigeration temperatures (4 °C), increasing one log count in three days. They exhibited slow acidification capacity, despite the increased production of lactic acid displayed by some strains after 24h. Bacteriocin activity was only detected in the whey of fresh cheese inoculated with two Enterococcus strains, but all cheeses made with bacteriocin-producing strains inhibited L. monocytogenes growth in the agar diffusion bioassay. No significant differences were found in overall sensory evaluation made by a non-trained panel of 50-52 tasters using the isolates as adjunct culture in fresh cheese, with the exception of one Enterococcus strain. To test the effect of in situ bacteriocin production against L. monocytogenes, fresh cheese was made from pasteurized cows' milk inoculated with bacteriocin-producing LAB and artificially contaminated with approximately 10(6) CFU/mL of L. monocytogenes. The numbers of L. monocytogenes were monitored during storage of fresh cheese at refrigeration temperature (4 °C) for up to 15 days. All strains controlled the growth of L. monocytogenes, although some Enterococcus were more effective in reducing the pathogen counts. After 7 days, this reduction was of approximately 4 log units compared to the positive control. In comparison, an increase of 4 log CFU/mL in pathogen numbers was

  18. Daya Antibakteri Filtrat Asam Laktat dan Bakteriosin Lactobacillus bulgaricus KS1 dalam Menghambat Pertumbuhan Klebsiella pneumoniae Strain ATCC 700603, CT1538, dan S941

    Directory of Open Access Journals (Sweden)

    Prima Nanda Fauziah

    2015-03-01

    Full Text Available Lactobacillus bulgaricus produces lactic acid and bacteriocin which have been reported to have various pharmacologic properties, including their role an antibacterial agent. Klebsiella pneumoniae, as an agent of pneumonia, remains a public health problem in tropical countries. This study was aimed to observe the antibacterial activities of lactic acid filtrate and bacteriocins of L. bulgaricus toward againsts K. pneumoniae strains by in vitro experiment. The experiment took place in Microbiology Laboratory, Teaching Hospital, Padjadjaran University, Bandung, August–October 2012. In vitro laboratory analytic study has been conducted on lactic acid filtrate and bacteriocins of L. bulgaricus against the K. pneumoniae strains. The study used agar pour plate and agar disk diffusion method and analyzed by ANAVA followed by Duncan’s multiple range test (DMRT. The 30% lactic acid filtrate and 20% bacteriocins filtrate concentrations of L. bulgaricus showed bactericidal characteristics againts the growth of K. pneumoniae strains. Greater concentration of lactic acid filtrate and bacteriocins of L. bulgaricus led toincreasing effect of growth inhibition zones of K. pneumoniae strains. Statistical analysis of variance (ANOVA showed that the greatest concentration effect of L. bulgaricus filtratefor inhibiting K. pneumoniae strains was achieved in 90% lactic acid filtrate concentration treatment, whereas the greatest inhibition zones for K. pneumoniae ATCC 700603 was obtaubed in 90% bacteriocins filtrate concentration, amounting 16.667 mm. In conclusion, lactic acid filtrate and bacteriocins L. bulgaricus have antibacterial effects on K. pneumoniae. The level of antibacterial effect of L. bulgaricus against the growth of K. pneumoniae strains depends on the type of filtrate, L. bulgaricus filtrate concentration, and K. pneumoniae strain.

  19. Technological properties and probiotic potential of Enterococcus faecium strains isolated from cow milk.

    Science.gov (United States)

    Banwo, K; Sanni, A; Tan, H

    2013-01-01

    To identify enterococci from the fermentation of milk for the production of nono, an African fermented dairy product, to determine the technological properties for suitability as starter cultures and safety as probiotics. Enterococcus faecium CM4 and Enterococcus faecium 2CM1 were isolated from raw cow's milk. The strains were phenotypically and genotypically identified. Technological properties, safety investigations, in vitro adherence properties and antimicrobial characteristics were carried out. Strong acidification and tolerance to bile salts were recorded. The strains were bile salts hydrolytic positive and no haemolysis. There was no resistance to clinically relevant antibiotics. The strains exhibited adherence to human collagen type IV, human fibrinogen and fibronectin. The bacteriocins were active against Bacillus cereus DSM 2301, Bacillus subtilis ATCC 6633, Micrococcus luteus and Listeria monocytogenes. Bacteriocins were stable at pH 4-9 and on treatment with lipase, catalase, α-amylase and pepsin, while their activity was lost on treatment with other proteases. The bacteriocins produced were heat stable at 100°C for 10 min. The bacteriocin produced by the strains was identified as enterocin A. The E. faecium strains in this study exhibited probiotic activity, and the safety investigations indicate their suitability as good candidates for a starter culture fermentation process. The use of bacteriocin-producing E. faecium strains as starter cultures in fermented foods is beneficial but, however, their safety investigations as probiotics must be greatly emphasized. © 2012 The Society for Applied Microbiology.

  20. Antibacterial activities of coagulase-negative staphylococci from bovine teat apex skin and their inhibitory effect on mastitis-related pathogens.

    Science.gov (United States)

    Braem, G; Stijlemans, B; Van Haken, W; De Vliegher, S; De Vuyst, L; Leroy, F

    2014-05-01

    To explore antibacterial activities of coagulase-negative staphylococci (CoNS) from teat apices of dairy cows towards mastitis-causing pathogens. Of 254 CoNS, 38 displayed bacteriocin-like activity after a first screening. Seven of these strains displayed activity against at least one mastitis-related pathogen (Streptococcus uberis, Streptococcus dysgalactiae and Staphylococcus aureus). Staphylococcus chromogenes L217 displayed the strongest inhibitory effect, being active against all tested mastitis-related pathogens and most tested CoNS. Based on cation exchange and reversed-phase chromatography, in addition to N-terminal Edman degradation and PCR, the antibacterial peptide was identified as a nukacin-type bacteriocin and named nukacin L217. Although staphylococcal bacteriocins are generally found in the cell-free supernatants of liquid cultures, Staph. chromogenes L217 only led to detectable activity when grown on agar medium. Bacteriocin-like activities are not uncommon among CoNS from teat apices and may inhibit mastitis-causing pathogens, as found for nukacin L217 production by Staph. chromogenes L217. Nukacin L217 is the first identified bacteriocin of the species Staph. chromogenes and displays unusual production kinetics, that is, requiring surface growth of its producer. The fact that nukacins are produced by different CoNS species suggests a role in the teat skin ecosystem. © 2014 The Society for Applied Microbiology.

  1. Characterization of bacteriocinogenic strains of lactic acid bacteria from traditional Slovenian cheese ‘Tolminc’

    Directory of Open Access Journals (Sweden)

    Aljoša Trmčić

    2010-12-01

    Full Text Available The purpose of this research was to examine traditional Slovenian ‘Tolminc’ cheese for the presence of lactic acid bacteria that produce several bacteriocins. The presence of gene determinants for different bacteriocins in this type of cheese and in the cultivable population of ‘Tolminc’ microbiota, have already been demonstrated, as well as its antimicrobial activity. Due to the difficulties in connecting the presence of gene determinants for bacteriocins with the observed antimicrobial activity it was decided to examine in this study the same features on the level of individual bacteriocinogenic strains. Like in previous results, enterococci and their bacteriocins prevailed in cheese microbial consortia. None of isolated strains inhibited growth of Staphylococcus aureus, while the other indicator strains were inhibited in a strain specific manner. Most of isolated strains carried gene determinants for cytolysin. On the basis of gene determinants for bacteriocins, antimicrobial activity, phenotyping by PhP (PhenePlateTM system and PCR identification, some similarities found were among Enterococcus isolates.

  2. Probióticos y Conservadores Naturales en Alimentos Probióticos y Conservadores Naturales en Alimentos

    Directory of Open Access Journals (Sweden)

    M. Bautista-Justo

    2012-02-01

    Full Text Available Los probióticos son alimentos que contienen bacterias que proporcionan un beneficio a la salud de quienes los consumen. Estas bacterias pueden producir proteínas llamadas bacteriocinas, que actúan como agentes antibacterianos. Las bacteriocinas pueden, además de proteger al hospedero contra el ataque de bacterias patógenas, también servir como bioconservadores en alimentos. Hasta ahora, la Nisina es la única bacteriocina que se usa comercialmente en la conservación de alimentos; sin embargo, existen otras con uso potencial como bioconservadores. En este trabajo analizamos aspectos generales de los probióticos, de los conservadores naturales, de las bacteriocinas tanto producidas por bacterias lácticas como por una bacteria que es bioinsecticida.Probiotics contain bacteria that provide benefits to the consumer’s health. Probiotic bacteria may produce proteins called bacteriocins which act as anti-microbial agents. Bacteriocins protect not only consumer against food-borne pathogenic bacteria, but also can play a role as preservatives in food. Currently, Nisin is the only bacteriocin used as a food additive, nevertheless there are other bacteriocins with a potential use as preservatives. In this work, a general overview is presented of probiotics, natural preservatives, bacteriocins from lacticbacteria, and those produced by aninsecticidal bacterium.

  3. Co-expression and characterization of enterocin CRL35 and its mutant in Escherichia coli Rosetta

    Directory of Open Access Journals (Sweden)

    Masías Emilse

    2014-01-01

    Full Text Available Even though many sequences and structures of bacteriocins from lactic acid bacteria have been fully characterized so far, little information is currently available about bacteriocins heterologously produced by Escherichia coli. For this purpose, the structural gene of enterocin CRL35, munA, was PCR-amplified using specific primers and cloned downstream of PelB sequence in the pET22b (+ expression vector. E. coli Rosetta (DE3 pLysS was chosen as the host for production and enterocin was purified by an easy two-step protocol. The bacteriocin was correctly expressed with the expected intramolecular disulfide bond. Nevertheless, it was found that a variant of the enterocin, differing by 12 Da from the native polypeptide, was co-expressed by E. coli Rosetta in comparable amount. Indeed, the mutant bacteriocin contained two amino acid substitutions that were characterized by matrix assisted laser desorption ionization-time of flight (MALDI-TOF and HPLCelectrospray (ESI-Q-TOF tandem mass spectrometry (MS/ MS sequencing. This is the first report regarding the production of mutants of pediocin-like bacteriocins in the E. coli expression system.

  4. High-salt brines compromise autoinducer-mediated bacteriocinogenic Lactobacillus plantarum survival in Spanish-style green olive fermentations.

    Science.gov (United States)

    Caballero-Guerrero, Belén; Lucena-Padrós, Helena; Maldonado-Barragán, Antonio; Ruiz-Barba, José Luis

    2013-02-01

    The effect of NaCl on plantaricin production by five Lactobacillus plantarum strains was investigated. Plantaricin production in these strains was found to be regulated by three-component regulatory systems ruled by two different autoinducer peptides (AIPs), either PLNC8IF or Plantaricin A. Bacteriocin activity exhibited by these strains came to a halt in liquid medium containing NaCl concentrations of or above 2%. In contrast, bacteriocin activity was still observed when the producing strains were growing on solid medium containing up to 4% NaCl. Bacteriocin activity in liquid medium containing up to 2% NaCl could be restored by coculturing the producing strains with a selected plantaricin-production inducing strain of Lactococcus lactis. Growth of these bacteriocinogenic L. plantarum strains was monitored in traditional Spanish-style green olive fermentations. Survival of these strains could not be enhanced when provided with a range of plantaricin-production inducing mechanisms previously described, such as constitutive AIP production or coinoculation with a specific bacteriocin-production inducing strain of L. lactis. Our results suggest that it is advisable the use of constitutive bacteriocin producers, or at least non-AIP-dependant ones, as starters for olive fermentations due to the intrinsic physical characteristics of this food fermentation, especially the high salt concentration of the brines currently used. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Anti-MRSA activities of Enterocins DD28 and DD93 and evidences on their role in the inhibition of biofilm formation

    Directory of Open Access Journals (Sweden)

    Ahmed Khassaf eAL ATYA

    2016-05-01

    Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA, along with other antibiotic resistant bacteria, has become a worrisome superbug worldwide. This work was aimed at studying the efficacies of two class IIb bacteriocins, enterocins DD28 and DD93, against MRSA-S1 grown in planktonic culture and embedded in biofilms. These bacteriocins were purified, from the cultures supernatants of Enterococcus faecalis 28 and 93, using a simplified purification procedure consisting in a cation exchange chromatography and a reversed-phase high-performance liquid chromatography. The anti-Staphylococcal activity of these bacteriocins was shown in-vitro by the assessment of the minimal inhibitory concentration (MIC. Afterwhich, a checkerboard and time-kill kinetics permitted unveiled a synergistic effect of these bacteriocins in combination with erythromycin and kanamycin against the clinical MRSA-S1. These bacteriocins alone or in combination with erythromycin and kanamycin were able to impede the formation of MRSA-S1 biofilms on stainless steel and glace devices as supported by the microbial cell counts, epifluorescence and Scanning Electron Microscope analyses.

  6. Inhibition of Staphylococcus aureus in vitro by bacteriocinogenic Lactococcus lactis KTH0-1S isolated from Thai fermented shrimp (Kung-som) and safety evaluation.

    Science.gov (United States)

    Saelao, Sutanate; Maneerat, Suppasil; Kaewsuwan, Sireewan; Rabesona, Hanitra; Choiset, Yvan; Haertlé, Thomas; Chobert, Jean-Marc

    2017-05-01

    Lactococcus lactis KTH0-1S isolated from Thai traditional fermented shrimp (Kung-som) is able to produce heat-stable bacteriocin and inhibits food spoilage bacteria and food-borne pathogens. The inhibitory effect of bacteriocin remained intact after treatment with different pHs and after heating, but was sensitive to some proteolytic enzymes. Addition of bacteriocin KTH0-1S to Staphylococcus aureus cultures decreased viable cell counts by 2.8 log CFU/ml, demonstrating a bactericidal mode of action. Furthermore, the growth of S. aureus decreased significantly after 12-h co-cultivation with bacteriocinogenic strain. The molecular mass of bacteriocin KTH0-1S was found to be 3.346 kDa after ammonium sulfate precipitation, reversed phase (C 8 Sep-Pak), cation-exchange chromatography, RP-HPLC on C 8 column and mass spectrometry (MS/MS) analysis. Bacteriocin KTH0-1S was identified as nisin Z using PCR amplification and sequencing. The majority of tested virulence factors were absent, confirming the safety. Evidenced inhibitory effect of this strain, the absence of virulence factors creates the possibility for its application as protective culture to inhibit pathogenic bacteria in the several fermented seafood products.

  7. Use of the Soft-agar Overlay Technique to Screen for Bacterially Produced Inhibitory Compounds.

    Science.gov (United States)

    Hockett, Kevin L; Baltrus, David A

    2017-01-14

    The soft-agar overlay technique was originally developed over 70 years ago and has been widely used in several areas of microbiological research, including work with bacteriophages and bacteriocins, proteinaceous antibacterial agents. This approach is relatively inexpensive, with minimal resource requirements. This technique consists of spotting supernatant from a donor strain (potentially harboring a toxic compound(s)) onto a solidified soft agar overlay that is seeded with a bacterial test strain (potentially sensitive to the toxic compound(s)). We utilized this technique to screen a library of Pseudomonas syringae strains for intraspecific killing. By combining this approach with a precipitation step and targeted gene deletions, multiple toxic compounds produced by the same strain can be differentiated. The two antagonistic agents commonly recovered using this technique are bacteriophages and bacteriocins. These two agents can be differentiated using two simple additional tests. Performing a serial dilution on a supernatant containing bacteriophage will result in individual plaques becoming less in number with greater dilution, whereas serial dilution of a supernatant containing bacteriocin will result a clearing zone that becomes uniformly more turbid with greater dilution. Additionally, a bacteriophage will produce a clearing zone when spotted onto a fresh soft agar overlay seeded with the same strain, whereas a bacteriocin will not produce a clearing zone when transferred to a fresh soft agar lawn, owing to the dilution of the bacteriocin.

  8. Resistência bacteriana e ação das bacteriocinas de Lactobacillus spp em Staphylococcus aureus isolados de mastite bovina

    Directory of Open Access Journals (Sweden)

    B.R. Pribul

    2011-06-01

    Full Text Available Staphylococcus aureus is the major pathogen causing intramammary infections in dairy cattle worldwide. Among the factors that contribute to its spread and infectious potential is the ability to overcome the mechanisms of antimicrobials activity. The present work investigated the antimicrobial resistance pattern and sensibility to bacteriocins produced by strains of Lactobacillus spp of 30 isolates of S. aureus from mastitis. From this, 29 are beta-lactamase producers. Eight isolates (26.6% showed resistance to at least four antibiotics being considered multiresistent. All of them were mecA-positive. Otherwise, all isolates tested showed sensibility to at least one of the four bacteriocin producer strains. Due to the significant depletion of the efficacy of antimicrobials, pathogen growth inhibition by bacteriocins seems an alternative of biological control in infectious processes.

  9. A single exposure to a sublethal pediocin concentration initiates a resistance-associated temporal cell envelope and general stress response in Listeria monocytogenes

    DEFF Research Database (Denmark)

    Laursen, Martin Frederik; Bahl, Martin Iain; Licht, Tine Rask

    2015-01-01

    Listeria monocytogenes can cause the potentially fatal food-borne disease listeriosis, and the use of bacteriocin-producing lactic acid bacteria to control L. monocytogenes holds great promise. However, development of bacteriocin resistance is a potential challenge and the purpose of this study...... was to determine if exposure to sublethal concentrations of pediocin-containing Lactobacillus plantarum WHE 92 supernatant could prime L. monocytogenes for resistance. By transcriptomic analysis, we found two, 55 and 539 genes differentially expressed after 10, 60 and 180 min of exposure to L. plantarum WHE 92...... supernatant as compared to control exposures. We observed temporal expression changes in genes regulated by the two component system LisRK and the alternative sigma factors SigB and SigL. Additionally, several genes involved in bacteriocin resistance were induced. ΔlisR, ΔsigB and ΔsigL mutants were all more...

  10. Isolation and identification of bacteriocinogenic strain of Lactobacillus plantarum with potential beneficial properties from donkey milk.

    Science.gov (United States)

    Murua, A; Todorov, S D; Vieira, A D S; Martinez, R C R; Cencič, A; Franco, B D G M

    2013-06-01

    The goal of this study was to isolate and characterize a lactic acid bacteria (LAB) from donkey milk with potential beneficial properties. Lactic acid bacteria were isolated from donkey milk and identified based on physiological, biochemical and molecular methods. The isolate that presented highest bacteriocin potential (Lactobacillus plantarum LP08AD) was evaluated for the production of bacteriocin, including stability in the presence of various enzymes, surfactants, salts, pH and temperatures. Bactericidal effect of bacteriocin LP08AD on Listeria monocytogenes, Enterococcus faecium and Lactobacillus curvatus was shown for actively growing and stationary cells. Similar growth and bacteriocin production were observed when strain LP08AD was cultured in MRS broth at 30°C or 37°C. Bacteriocin LP08AD adhered at low levels on the producer cells (200 AU ml(-1) ). The presence of plantaricin W gene on the genomic DNA was recorded based on PCR. Good growth for strain LP08AD was recorded in MRS broth with pH from 5·0 to 9·0 and LP08AD grew well in the absence of oxbile or concentration below 0·8%. Lact. plantarum LP08AD was applied to the small intestinal epithelial polarized monolayers of H4, PSIc1 and CLAB and demonstrated low attachment ability on all cell lines studied, with values with a similar behaviour for cells from human and pig origin. Bacteriocin-producing Lact. plantarum LP08AD might be useful in the design of novel functional foods with potential probiotic or biopreservation properties. To the best of our knowledge, this is the first report on detection and characterization of bacteriocinogenic Lact. plantarum from donkey milk. The strain LP08AD shows to have potential beneficial properties, as demonstrated by the use of noncancerogenic cell lines. © 2013 The Society for Applied Microbiology.

  11. Characterization and antimicrobial activity of vaginal lactobacillus isolate

    Directory of Open Access Journals (Sweden)

    Zavišić Gordana

    2011-01-01

    Full Text Available The aim of this study was to investigate the probiotic potential of bacteriocin-producing lactobacilli strain Lactobacillus plantarum G2 isolated from the vaginal mucus of healthy women. The antimicrobial effect of G2 was confirmed in the mixed culture with pathogenic Escherichia coli, Staphylococcus aureus, Salmonella abony and Pseudomonas aeruginosa, while bacteriocine activity was detected against S. aureus and S. abony only. The strain showed an excellent survival rate in low pH and in the presence of bile salts. The percentage of adhered cells of L. plantarum G2 to hexadecane was 63.85±2.0 indicating the intermediate hydrophobicity.

  12. Antimicrobial Activity – The Most Important Property of Probiotic and Starter Lactic Acid Bacteria

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    Blaženka Kos

    2010-01-01

    Full Text Available The antimicrobial activity of industrially important lactic acid bacteria as starter cultures and probiotic bacteria is the main subject of this review. This activity has been attributed to the production of metabolites such as organic acids (lactic and acetic acid, hydrogen peroxide, ethanol, diacetyl, acetaldehyde, acetoine, carbon dioxide, reuterin, reutericyclin and bacteriocins. The potential of using bacteriocins of lactic acid bacteria, primarily used as biopreservatives, represents a perspective, alternative antimicrobial strategy for continuously increasing problem with antibiotic resistance. Another strategy in resolving this problem is an application of probiotics for different gastrointestinal and urogenital infection therapies.

  13. Antimicrobial properties of lactic acid bacteria isolated from uruguayan artisan cheese

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    Martín Fraga Cotelo

    2013-12-01

    Full Text Available Uruguayan artisan cheese is elaborated with raw milk and non-commercial starters. The associated native microbiota may include lactic acid bacteria and also potentially pathogenic bacteria. Lactic acid bacteria were isolated from artisan cheese, raw milk, and non-commercial starter cultures, and their potential bacteriocin production was assessed. A culture collection of 509 isolates was obtained, and five isolates were bacteriocin-producers and were identified as Enterococcus durans,Lactobacillus casei, and Lactococcus lactis. No evidence of potential virulence factors were found in E. durans strains. These are promising results in terms of using these native strains for cheese manufacture and to obtain safe products.

  14. De novo structural modeling and computational sequence analysis ...

    African Journals Online (AJOL)

    Jane

    2011-07-25

    Jul 25, 2011 ... Our study was aimed towards computational proteomic analysis and 3D structural modeling of this novel bacteriocin protein encoded by the earlier aforementioned gene. Different bioinformatics tools and machine learning techniques were used for protein structural classification. De novo protein modeling ...

  15. Complete Genome Sequence of Bacillus horikoshii Strain 20a from Cuatro Cienegas, Coahuila, Mexico

    OpenAIRE

    Zarza, Eugenia; Alcaraz, Luis D.; Aguilar-Salinas, Bernardo; Islas, Africa; Olmedo-?lvarez, Gabriela

    2017-01-01

    ABSTRACT We sequenced the Bacillus horikoshii 20a genome, isolated from sediment collected in Cuatro Cienegas, Mexico. We identified genes involved in establishing antagonistic interactions in microbial communities (antibiotic resistance and bacteriocins) and genes related to the metabolism of cyanophycin, a reserve compound and spore matrix material potentially relevant for survival in an oligotrophic environment.

  16. Bacteriocinogenic potential and genotypic characterization of three ...

    African Journals Online (AJOL)

    Louiza

    2015-08-06

    Aug 6, 2015 ... Traditional food manufacturing appreciated to this day by some consumers was at the origin of products from the food industry. In old times, an excess of food need to be conserved ... industry and medical society attempt to use bacteriocins ... M17 broth media (Fluka, Switzerland) at 30°C. Several bacteria.

  17. Short Communication A study on the bactericidal effect of nisin ...

    African Journals Online (AJOL)

    Nisin, the best known LAB (Lactic Acid Bacteria) bacteriocin, is a promising alternative to antibiotics, and displays a broad spectrum of activity against a wide range of spoilage and pathogenic Gram positive bacteria. The aim of the study was to determine the bactericidal effect of nisin. The Lactococcus lactis MTCC 440 used ...

  18. Bactericidal mode of action of plantaricin C

    NARCIS (Netherlands)

    González, Beatriz; Glaasker, Erwin; Kunji, Edmund R.S.; Driessen, Arnold J.M.; Suárez, Juan E.; Konings, Wil N.

    Plantaricin C is a bacteriocin produced by Lactobacillus plantarum LL441 that kills sensitive cells by acting on the cytoplasmic membrane. In contrast to its lack of impact on immune cells, plantaricin C dissipates the proton motive force and inhibits amino acid transport in sensitive cells. In

  19. Evaluation of lactic acid and thermophilic bacteria antibacterial activity and compatibility with prebiotic oligosaccharides for development of new synbiotics

    OpenAIRE

    Pranckutė, Raminta

    2017-01-01

    Increased demand of nowadays consumers for less processed, with no chemical preservatives but beneficial to health food products forces the research on compatibility studies of functional food components – probiotic bacteria and prebiotics, aiming to create effective synbiotics. Probiotic bacteria produce various antibacterial substances and bacteriocins among them. These proteinaceous molecules attracted enormous attention due to the widespread pathogenic bacteria resistance to conventional ...

  20. Original Research

    African Journals Online (AJOL)

    2013-12-25

    Dec 25, 2013 ... Organic acids, including sorbic acid (trans-trans-2,4-hexadienoic acid), benzoic acid ... In this respect, special interest has been focused on bacteriocins produced by lactic acid bacteria (LAB). ... synthesis of histamine in commonly available edible fish, tuna under laboratory conditions treated with crude ...

  1. Methods and means for producing improved dairy products

    NARCIS (Netherlands)

    Hup, Gerhard; Nauta, Arjen; Kemperman, Robèr Antoine; Kok, Jan; Kuipers, Oscar

    2001-01-01

    Bacteriocins produced by "food-grade" lactic acid bacteria (LAB) are successfully used as food preservatives. However, they are often characterised by a narrow inhibitory spectrum, acting mainly on closely related bacteria. In order to specifically prevent the growth of spoilage Clostridia, we set

  2. 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

  3. 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

  4. African Journal of Biotechnology - Vol 10, No 51 (2011)

    African Journals Online (AJOL)

    Antimicrobial activities of the bacteriocin-like substances produced by lactic acid bacteria isolated from Moroccan dromedary milk · EMAIL FREE FULL TEXT EMAIL ... Effect of cooking methods on chemical composition, quality and cook loss of camel muscle (Longissimus dorsi) in comparison with veal · EMAIL FREE FULL ...

  5. Antibacterial activity and probiotic properties of some lactic acid ...

    African Journals Online (AJOL)

    Several lactic acid bacteria strains were screened for the production of antibacterial substances active against some pathogenic bacteria. The inhibitory mechanism was investigated and was shown to be dependant of bacteriocin production. The objective was to isolate LAB with antibacterial activity from raib and to select ...

  6. Proteins of the lactococcin A secretion system : lcnD encodes two in-frame proteins

    NARCIS (Netherlands)

    Varcamonti, M; Nicastro, G; Venema, G; Kok, J

    2001-01-01

    Polyclonal antibodies were raised against LcnC and LcnD proteins of the Lactococcus lactis bacteriocin lactococcin A secretory system to examine their cellular location and interaction. Two major reacting bands were detected by Western immunoblot with the anti-LcnD antibody: one of 52 kDa (LcnD) and

  7. Persistence of colicinogenic Escherichia coli in the mouse gastrointestinal tract

    Directory of Open Access Journals (Sweden)

    Giladi Itamar

    2009-08-01

    Full Text Available Abstract Background The ability of a bacterial strain to competitively exclude or displace other strains can be attributed to the production of narrow spectrum antimicrobials, the bacteriocins. In an attempt to evaluate the importance of bacteriocin production for Escherichia coli strain residence in the gastrointestinal tract, a murine model experimental evolution study was undertaken. Results Six colicin-producing, yet otherwise isogenic, E. coli strains were administered and established in the large intestine of streptomycin-treated mice. The strains' persistence, population density, and doubling time were monitored over a period of 112 days. Early in the experiment only minor differences in population density between the various colicin-producing and the non-producing control strains were detected. However, over time, the density of the control strains plummeted, while that of the colicin-producing strains remained significantly higher (F(7,66 = 2.317; P Conclusion The data presented here support prior claims that bacteriocin production may play a significant role in the colonization of E. coli in the gastrointestinal tract. Further, this study suggests that the ability to produce bacteriocins may prove to be a critical factor in determining the success of establishing probiotic E. coli in the gastrointestinal tract of humans and animals.

  8. Characterization of anti-listerial lactic acid bacteria isolated from Thai fermented fish products

    DEFF Research Database (Denmark)

    Østergaard, Anya; Embarek, Peter Karim Ben; Wedell-Neergaard, C.

    1998-01-01

    further characterized and 43 strains were inhibitory against Listeria monocytogenes. The strains were inhibitory to other Gram- positive (lactic acid) bacteria probably because of production of bacteriocins. All 44 strains inhibited both Vibrio cholerae and Vibrio parahaemolyticus and 37 were inhibitory...

  9. Antimicrobial activity of autochthonous lactic acid bacteria isolated ...

    African Journals Online (AJOL)

    Twenty samples of traditional fermented milk “Raib” were collected in eastern Algeria from individual household. They were evaluated for the presence of autochthonous bacteriocin-producing lactic acid bacteria. From 13 of these samples 52 strains of lactic acid bacteria were isolated, and shown to exhibit inhibitory activity ...

  10. Antibacterial activity and probiotic properties of some Lactic Acid ...

    African Journals Online (AJOL)

    Client

    2013-05-15

    May 15, 2013 ... producing LAB like starter cultures for food preservation has received a special attention (Sabia et al., 2002). Moreover, bacteriocins are innocuous due to proteolytic degradation in the gastrointestinal tract ( Vuyst and. Vandammemmm, 1994). Streptococcus thermophilus is a lactic acid bacterium of.

  11. Antimicrobial activities of lactic acid bacteria isolated from akamu ...

    African Journals Online (AJOL)

    SAM

    2014-07-16

    Jul 16, 2014 ... Key words: Bacteriocins, lactic acid bacteria (LAB), target organisms, antimicrobial activity. INTRODUCTION. Lactic acid bacteria (LAB) play essential roles in the fermentative production of many traditional foods. A wide variety of strains are routinely used as starter cultures in the manufacture of fermented ...

  12. Structure and biological activity of chemically modified nisin A species

    NARCIS (Netherlands)

    Rollema, Harry S.; Metzger, Jörg W.; Both, Paula; Kuipers, Oscar P.; Siezen, Roland J.

    1996-01-01

    Nisin, a 34-residue peptide bacteriocin, contains the less common amino acids lanthionine, β-methyllanthionine, dehydroalanine (Dha), and dehydrobutyrine (Dhb). Several chemically modified nisin A species were purified by reverse-phase HPLC and characterized by two-dimensional NMR and electrospray

  13. Efficacy of Sakacin on Selected Food Pathogenic Microorganisms ...

    African Journals Online (AJOL)

    Bacteriocins are antimicrobial substances of lactic acid bacteria (LAB) have gained tremendous attention as potential bio preservatives in the food and dairy industries. The LAB can serve as probiotics, which are products aimed at delivering living, potentially beneficial bacterial cells to the gut ecosystem of humans and ...

  14. Screening of malting sorghum samples for lactic acid bacteria with ...

    African Journals Online (AJOL)

    catalase of these inhibitory compounds from the seven bacteria identified them as bacteriocins. Based on standard biochemical and microbiological tests, the isolates were tentatively identified as belonging to Lactococcus spp., Leuconostoc spp., Lactobacillus spp. and Streptococcus spp. However, three isolates (GS3A, ...

  15. Draft Genome Sequence of Hoeflea sp. Strain BAL378, a Potential Producer of Bioactive Compounds

    DEFF Research Database (Denmark)

    Bentzon-Tilia, Mikkel; Riemann, Lasse; Gram, Lone

    2014-01-01

    Some phytoplankton-associated marine bacteria produce bioactive compounds. Members of the genus Hoeflea may be examples of such bacteria; however, data describing their metabolisms are scarce. Here, we report the draft genome sequence of Hoeflea sp. strain BAL378, a putative producer of bacterioc...... of bacteriocins, polyketides, and auxins, as demonstrated by genome mining....

  16. Screening for anti-methicillin resistant Staphylococcus aureus ...

    African Journals Online (AJOL)

    Methicillin resistant bacterial infections give a tough challenge in the selection of antibiotics. Traditional use of antibiotics is worsening the problem day by day. So, it is essential to sort out other strategies which can replace antibiotic therapy successfully. Bacteriocins are the proteinaceous compounds with a narrower ...

  17. Antimicrobial activity of lactic acid bacteria isolated from bekasam against staphylococcus aureus ATCC 25923, escherichia coli ATCC 25922, and salmonella sp

    Science.gov (United States)

    Sari, Melia; Suryanto, Dwi; Yurnaliza

    2018-03-01

    Bekasam is an Indonesian fermented food made of fish. As a fermented food, this food may contain some beneficial bacteria like lactic acid bacteria (LAB), which usually have antimicrobial properties such as organic acid, hydrogen peroxide, and a bacteriocin. A study on antimicrobial activity of LAB isolated from bekasam against some pathogenic bacteria has been conducted. The purpose of this study was to know the ability of crude bacteriocin produced LAB of bekasam against Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Salmonella sp. Bekasam sample was taken from South Sumatera. LAB isolation was done using de Man Rogosa and Sharpe agar. A bacterial colony with clear zone was selected and purified to get a single colony. The antagonistic assay of the LAB was conducted in Muller-Hinton agar Selected isolates with higher clearing zone were assayed for antibacterial effect of their crude bacteriocin of different culture incubation time of 6, 9, and 12 hours. The results showed that the crude extract bacteriocin of isolate MS2 of 9 hours culture incubation time inhibited more in Staphylococcus aureus ATCC 25923 with inhibition zone of 13.1 mm, whereas isolate MS9 of 9 hours culture incubation time inhibited more in Escherichia coli ATCC 25922 and Salmonella sp. with inhibition zone of 12.7 and 7.3 mm, respectively.

  18. In vitro antimicrobial characteristics of bacteriocinproducing ...

    African Journals Online (AJOL)

    A total of 50 bacteriocin-producing Lactobacillus strains isolated from some Nigerian indigenous fermented foods and beverages (ogi, fufu, garri and nono) and characterized as L. acidophilus, L. casei, L. fermentum, L. lactis and L. plantarum were screened for their inhibitory potentials against food-borne pathogenic ...

  19. Functional analysis of the pediocin operon of Pediococcus acidilactici PAC1.0 : PedB is the immunity protein and PedD is the precursor processing enzyme

    NARCIS (Netherlands)

    Venema, Konraad; Kok, Jan; Marugg, Joey D.; Toonen, Marjolein Y.; Ledeboer, Aat M.; Venema, Gerhardus; Chikindas, Michael L.

    The bacteriocin pediocin PA-1 operon of Pediococcus acidilactici PAC1.0 encompasses four genes: pedA, pedB, pedC and pedD. Transcription of the operon results in the formation of two overlapping transcripts, probably originating from a single promoter upstream of pedA. The major transcript comprises

  20. Some technological properties of phenotypically identified ...

    African Journals Online (AJOL)

    All of the 39 enterococci strains were sensitive to vancomycin (30 g vancomycin per disk, inhibition zone > 12 mm). Three E. faecium (EYT17, EYT31 and EYT39) and 1 E. durans (EYT19) strains were found as bacteriocin producer. E. faecium strains showed higher acidifying ability than E. faecalis and E. durans strains.

  1. BACTERICIDAL COATINGS ON TEXTILES FOR REMEDIATION OF INTERMICROBE ACTIVITY (BaCTeRIA) SUMMARY REPORT

    Science.gov (United States)

    2017-07-07

    TEXTILES FOR REMEDIATION OF INTERMICROBE ACTIVITY ( BaCTeRIA ) SUMMARY REPORT by Tobyn A. Branck Courtney M. Cowell Jennifer M. Rego and...October 2011 – September 2015 4. TITLE AND SUBTITLE BACTERICIDAL COATINGS ON TEXTILES FOR REMEDIATION OF INTERMICROBE ACTIVITY ( BaCTeRIA ) SUMMARY REPORT...ANTHRAX PURIFICATION BACILLUS ANTHRACIS ENVIRONMENTAL ISOLATES BACTERIA BACTERIOCINS TARGETED ACTIVITY

  2. 2537-IJBCS-Article-Essodolom Taale

    African Journals Online (AJOL)

    hp

    2005. Bacteriocins: developing innate immunity for food. Nature Reviews. Microbiology, 3(10): 777-788. doi: http://dx.doi.org/10.1038/nrmicro1273. De Zamaroczy M, Chauleau M. 2011. Colicin killing: foiled cell defense and hijacked cell functions. In. Prokaryotic Antimicrobial Peptides: From Genes to Applications, Drider D,.

  3. Efficacy of Sakacin on Selected Food Pathogenic Microorganisms ...

    African Journals Online (AJOL)

    USER

    Lactobacillus brevis and Lactobacillus reuteri for bacteriocin ... UAL187,. Lactobacillus helveticus 481 and Camobacterium piscicola LV17 as. Nisin, pediocin A, Pediocin AcH, Lecucocin,. Helveticin J and Camobacteriocin repectively. Similarly ... bioassay strains (Escherichia coli N2, Pseudomonas aeruginosa N7,Listeria ...

  4. Genetic basis for the resistance of Staphylococcus aureus to peptidoglycan hydrolase by comparative transcriptome and whole genome sequence analysis

    Science.gov (United States)

    Background: Lysostaphin is a glycyl-glycine bacteriocin peptidoglycan hydrolase secreted by Staphylococcus simulans for degrading the peptidoglycan moieties in Staphylococcus aureus cell walls which result in cell lysis. There are known mechanisms of resistance to lysostaphin, e.g. serine in place...

  5. African Journal of Biotechnology - Vol 8, No 3 (2009)

    African Journals Online (AJOL)

    Screening for anti-methicillin resistant Staphylococcus aureus (MRSA) bacteriocin producing bacteria · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD ... Seed germination and in vitro propagation of Piliostigma thonningii – an important medicinal plant · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  6. Strategies for Pathogen Biocontrol Using Lactic Acid Bacteria and Their Metabolites: A Focus on Meat Ecosystems and Industrial Environments

    Directory of Open Access Journals (Sweden)

    Patricia Castellano

    2017-07-01

    Full Text Available The globalization of trade and lifestyle ensure that the factors responsible for the emergence of diseases are more present than ever. Despite biotechnology advancements, meat-based foods are still under scrutiny because of the presence of pathogens, which causes a loss of consumer confidence and consequently a fall in demand. In this context, Lactic Acid Bacteria (LAB as GRAS organisms offer an alternative for developing pathogen-free foods, particularly avoiding Listeria monocytogenes, with minimal processing and fewer additives while maintaining the foods’ sensorial characteristics. The use of LAB strains, enabling us to produce antimicrobial peptides (bacteriocins in addition to lactic acid, with an impact on quality and safety during fermentation, processing, and/or storage of meat and ready-to-eat (RTE meat products, constitutes a promising tool. A number of bacteriocin-based strategies including the use of bioprotective cultures, purified and/or semi-purified bacteriocins as well as their inclusion in varied packaging materials under different storage conditions, have been investigated. The application of bacteriocins as part of hurdle technology using non-thermal technologies was explored for the preservation of RTE meat products. Likewise, considering that food contamination with L. monocytogenes is a consequence of the post-processing manipulation of RTE foods, the role of bacteriocinogenic LAB in the control of biofilms formed on industrial surfaces is also discussed.

  7. Strategies for Pathogen Biocontrol Using Lactic Acid Bacteria and Their Metabolites: A Focus on Meat Ecosystems and Industrial Environments.

    Science.gov (United States)

    Castellano, Patricia; Pérez Ibarreche, Mariana; Blanco Massani, Mariana; Fontana, Cecilia; Vignolo, Graciela M

    2017-07-11

    The globalization of trade and lifestyle ensure that the factors responsible for the emergence of diseases are more present than ever. Despite biotechnology advancements, meat-based foods are still under scrutiny because of the presence of pathogens, which causes a loss of consumer confidence and consequently a fall in demand. In this context, Lactic Acid Bacteria (LAB) as GRAS organisms offer an alternative for developing pathogen-free foods, particularly avoiding Listeria monocytogenes , with minimal processing and fewer additives while maintaining the foods' sensorial characteristics. The use of LAB strains, enabling us to produce antimicrobial peptides (bacteriocins) in addition to lactic acid, with an impact on quality and safety during fermentation, processing, and/or storage of meat and ready-to-eat (RTE) meat products, constitutes a promising tool. A number of bacteriocin-based strategies including the use of bioprotective cultures, purified and/or semi-purified bacteriocins as well as their inclusion in varied packaging materials under different storage conditions, have been investigated. The application of bacteriocins as part of hurdle technology using non-thermal technologies was explored for the preservation of RTE meat products. Likewise, considering that food contamination with L. monocytogenes is a consequence of the post-processing manipulation of RTE foods, the role of bacteriocinogenic LAB in the control of biofilms formed on industrial surfaces is also discussed.

  8. Combinations of nisin with salt (NaCl) to control Listeria ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-02-22

    Feb 22, 2010 ... Jack RW, Tagg JR, Ray B (1995). Bacteriocins of Gram positive bacteria. Microbiol. Rev. 59: 171–200. Lee KT, Kim HR, Kataoka (1994). Studies on the preparation and utilization of hog small intestine. II. Effect of salting level on the quality characteristics of small casings, Asian Aust. J. Anim. Sci. 7: 532-526.

  9. Processing of byproducts to improve nisin production by ...

    African Journals Online (AJOL)

    One of them is its utilization as culture media, aiming to produce biomolecules with noble applications. Nisin is an extracellular peptide, produced by Lactococcus lactis, this peptide has been applied as a natural additive once it presents broad antibacterial activity. Applications of this bacteriocin include dental care products, ...

  10. Potential aquaculture probiont Lactococcus lactis TW34 produces nisin Z and inhibits the fish pathogen Lactococcus garvieae.

    Science.gov (United States)

    Sequeiros, Cynthia; Garcés, Marisa E; Vallejo, Marisol; Marguet, Emilio R; Olivera, Nelda L

    2015-04-01

    Bacteriocin-producing Lactococcus lactis TW34 was isolated from marine fish. TW34 bacteriocin inhibited the growth of the fish pathogen Lactococcus garvieae at 5 AU/ml (minimum inhibitory concentration), whereas the minimum bactericidal concentration was 10 AU/ml. Addition of TW34 bacteriocin to L. garvieae cultures resulted in a decrease of six orders of magnitude of viable cells counts demonstrating a bactericidal mode of action. The direct detection of the bacteriocin activity by Tricine-SDS-PAGE showed an active peptide with a molecular mass ca. 4.5 kDa. The analysis by MALDI-TOF-MS detected a strong signal at m/z 2,351.2 that corresponded to the nisin leader peptide mass without the initiating methionine, whose sequence STKDFNLDLVSVSKKDSGASPR was confirmed by MS/MS. Sequence analysis of nisin structural gene confirmed that L. lactis TW34 was a nisin Z producer. This nisin Z-producing strain with probiotic properties might be considered as an alternative in the prevention of lactococcosis, a global disease in aquaculture systems.

  11. 1 ORIGINAL ARTICLE

    African Journals Online (AJOL)

    boaz

    therapeutic agent that can be employed in wound care and management. Key Words: Enterocin, Enterococcus faecalis, wounds, bacteriocin, Staphylococcus aureus, skin. L'ACTIVITE ANTIMICROBIENNE IN VITRO ET IN ... in the food industry since they inhibit the growth of most bacteria that spoil and contaminate food (1,6 ...

  12. Purification, Characterization and Antibacterial Mechanism of ...

    African Journals Online (AJOL)

    The agent is a hydrophobic protein with more acidic groups. Keywords: Lactobacillus acidophilus ... kind of antibacterial polypeptide, protein or protein compound [2-4] produced by the ..... A = E. coli cells were treated by the bacteriocins (magnification of 6,000, scale bar = 10 μm); B = no treatment as control (magnification of ...

  13. Leucocins 4010 from Leuconostoc carnosum cause a matrix related decrease in intracellular pH of Listeria monocytogenes

    DEFF Research Database (Denmark)

    Fang, Weihuan; Budde, Birgitte Bjørn; Siegumfeldt, Henrik

    2006-01-01

    A mixed culture of single cells of Listeria monocytogenes and the bacteriocin producing Leuconostoc carnosum 4010 showed growth inhibition of L. monocytogenes, although the intracellular pH (pHi) of L. monocytogenes followed by fluorescence ratio imaging microscopy was not affected. Furthermore, L...

  14. Draft Genome Sequences of Bacillus cereus E41 and Bacillus anthracis F34 Isolated from Algerian Salt Lakes

    OpenAIRE

    Daas, Mohamed Seghir; Rosana, Albert Remus R.; Acedo, Jeella Z.; Nateche, Farida; Kebbouche-Gana, Salima; Vederas, John C.; Case, Rebecca J.

    2017-01-01

    ABSTRACT Two strains of Bacillus, B.?cereus E41 and B.?anthracis F34, were isolated from a salt lake in A?n M?lila-Oum El Bouaghi, eastern Algeria, and Ain Baida-Ouargla, southern Algeria, respectively. Their genomes display genes for the production of several bioactive secondary metabolites, including polyhydroxyalkanoate, iron siderophores, lipopeptides, and bacteriocins.

  15. Optimization of nutritional and non-nutritional factors involved for production of antimicrobial compounds from Lactobacillus pentosus SJ65 using response surface methodology

    Directory of Open Access Journals (Sweden)

    Appukuttan Saraniya

    2014-01-01

    Full Text Available Bacteriocins from lactic acid bacteria are ribosomal synthesized antibacterial proteins/ peptides having wide range of applications. Lactobacillus pentosus SJ65, isolated from fermented Uttapam batter (used to prepare south Indian pan cake, produces bacteriocin having a broad spectrum of activity against pathogens. Optimization studies are of utmost important to understand the source of utilization and the conditions to enhance the production of metabolites. In the present study, an attempt was made to identify the parameters involved for maximal production of antimicrobial compounds especially bacteriocin from the isolate L. pentosus SJ65. Initially, optimal conditions, such as incubation period, pH, and temperature were evaluated. Initial screening was done using methodology onevariable-at-a-time (OVAT for various carbon and nitrogen sources. Further evaluation was carried out statistically using Plackett-Burman design and the variables were analyzed using response surface methodology using central composite design. The optimum media using tryptone or soy peptone, yeast extract, glucose, triammonium citrate, MnSO4, dipotassium hydrogen phosphate and tween 80 produced maximum bacteriocin activity.

  16. Lactococcins : Mode of action, immunity and secretion

    NARCIS (Netherlands)

    Venema, K; Kok, J; Venema, Gerhardus

    1995-01-01

    Lactococcus lactis subsp. cremoris 9B4 produces three small (around 5kDa), heat-stable, non-lanthionine containing, membrane active bacteriocins. Amino acid uptake experiments and proton motive force measurements have indicated that these peptides most probably form pores in the cytoplasmic membrane

  17. ANÁLISIS ESTRUCTURAL DE FILETES SAJADOS DE HÍBRIDO DE CACHAMA Piaractus braquypomus x Colossoma macropomum UTILIZANDO BACTERIOCINAS PRODUCIDAS POR Lactobacillus plantarum LPBM10 EMPACADO AL VACÍO

    Directory of Open Access Journals (Sweden)

    Héctor Suárez M

    2008-08-01

    Full Text Available Objective. To determine microstructure, texture and sensory changes in cut cachama hybrid fillets. Materials and methods. Hybrid fillets that were vacuum packed for 30 days at 3°C were analyzed after preservative treatments by crude bacteriocins extract, lactic acid, and control by light microscopy. Results. Space among the muscle fibers increased gradually and the architectural arrangement was altered in all treatments throughout the entire storage period. The lowest alteration in connective tissue degradation and lowest increment in spaces between the muscular fibers was observed with the crude bacteriocin extract treatment. The instrumental textural analysis showed no statistical difference in the stability loss of tissues from fillets among treatments. Sensory analysis indicated that the lancing treatment was effective in diminishing the negative effect of intramuscular bones. The best scores were for cutting fillets with the bacteriocin treatment. Conclusions. The meat texture of fillets was affected during the storage period. Lancing is a procedure that enables the use of fillets without encountering the intramuscular bone problem. The use of crude bacteriocins extract prolongs the shelf-life of fillets.

  18. ANTIMICROBIAL ACTIVITY OF PROBIOTIC STRAIN Lactobacillus plantarum ISOLATED FROM “SHA’A” AND ASSESSMENT OF ITS VIABILITY IN LOCAL HONEY

    Directory of Open Access Journals (Sweden)

    Zambou Ngoufack François

    2013-12-01

    Full Text Available The acid and bile tolerant strain of Lactobacillus plantarum 2S isolated from sha’a, a maize-based traditionally fermented beverage from Cameroon, was screened for bacteriocin properties and its viability in local pasteurized honey. Bacteriocin activity were checked after their treatment with different enzymes, organic solvents, sodium chloride (NaCl and detergents as well as their heat stability and effect of pH was studied. This strain produced an antimicrobial substance sensitive to proteolytic enzymes (trypsin and pepsin, thus confirming its proteinaceous nature. pH changes and heat treatment up to 121°C had no effect on the activity of the bacteriocin produced. This bacteriocins inhibited the growth of various indicator organisms with Lactobacillus plantarum 5S having the widest inhibition spectrum. Besides, it showed broad antibacterial activity spectrum against Gram-positive and Gram-negative pathogens including several that are classified as Especially Dangerous Infections by World Health Organization. The mode of action against Lactobacillus plantarum 5S and Salmonella enterica subsp. enterica serovare Typhi ATCC 6539 is bacteriostatic. After 28 days of storage at 4 °C or 25°C, the viable cell numbers of all bacterial strain in both samples were not changed. Lactobacillus plantarum 2S exhibited best viability in honey stored at 4 °C for 28 days and did not altered the physico-chemical characteristics of honey.

  19. A probiotic bacterium, Pediococcus pentosaceus OZF, isolated from ...

    African Journals Online (AJOL)

    Pediococcus pentosaceus OZF, originally isolated from healthy human breast milk, produces antimicrobial activities against many gram-positive bacterial species, including the food borne pathogen, Listeria monocytogenes. A bacteriocin was purified to homogeneity from the supernatant of exponentially growing cells using ...

  20. Antimicrobials of Bacillus species: mining and engineering

    NARCIS (Netherlands)

    Zhao, Xin

    2016-01-01

    Bacillus sp. have been successfully used to suppress various bacterial and fungal pathogens. Due to the wide availability of whole genome sequence data and the development of genome mining tools, novel antimicrobials are being discovered and updated,;not only bacteriocins, but also NRPs and PKs. A

  1. Screening bactericidal effect of Pectobacterium carotovorum subsp. carotovorum strains against causal agent of potato soft rot.

    Science.gov (United States)

    Kazemi-Zaromi, Samaneh; Baghaee-Ravari, Sareh; Khodaygan, Pejman; Falahati-Rastegar, Mahrokh

    2016-02-01

    This study focuses on the potential of Pectobacterium carotovorum subsp. carotovorum (Pcc) strains producing bacteriocin as a tool to control potato soft rot disease. Thirty out of 48 purified bacterial strains were characterized as Pcc using specific PCR and phenotypic tests. The pathogenicity and pectate degrading assays were recorded positive for 13 strains. Bacteriocin typing clustered producers into three groups according to their antimicrobial spectra. Majority of the producers except strains of group II showed antibacterial activity toward relative genus and the role of UV or mitomycin C was inductive. In addition, none of the distant genus was sensitive to Pcc bacteriocins except Rhizobium vitis. Molecular detection of four bacteriocins including carotovoricin, carosin S1, S2 and carosin D was performed. Overall, 54.5% of group I, 47.3 and 70% of groups II and III strains carried carotovoricin and four strains harbored gene corresponding to carosin S1. According to our data divers antimicrobial patterns obtained by Pcc strains and existence of new bateriocines could be possible. Moreover, our findings recommended that direct application of P29 or expression of corresponding genes of Pog22 or P21 in a nonpathogenic strain as a biocontrol agent may improve soft rot disease control. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Growth control of Listeria monocytogenes on cold-smoked salmon using a competitive lactic acid bacteria flora

    DEFF Research Database (Denmark)

    Nilsson, Lilian; Gram, Lone; Huss, Hans Henrik

    1999-01-01

    . sake LKE5 caused strong sulfurous off-flavors and was rejected as a culture for biopreservation of cold-smoked salmon. A bacteriocin-producing strain of C. piscicola (A9b) initially caused a 7-day lag phase of L. monocytogenes, followed by a reduction in numbers of L. monocytogenes from 10(3) CFU...

  3. Influence des substrats carbonés et minéraux sur l'activité des ...

    African Journals Online (AJOL)

    p < 0.0001). BLIS were stable to heat treatment ranging from 50 °C to 100 °C for 30 min. Conclusion and application of findings: These inhibitory substances produced, could be bacteriocins and could contribute to a better food preservation.

  4. Recent approaches in food bio-preservation - a review | Singh ...

    African Journals Online (AJOL)

    Apart from LAB metabolites, bacteriophages and endolysins has promising role in food processing, preservation and safety. Bacteriocins and endolysins are more suitable for DNA shuffling and protein engineering to generate highly potent variants with expanded activity spectrum. Genetically modified bacteriophages may ...

  5. Divergent metabolic outcomes arising from targeted manipulation of the gut microbiota in diet-induced obesity.

    Science.gov (United States)

    Murphy, Eileen F; Cotter, Paul D; Hogan, Aileen; O'Sullivan, Orla; Joyce, Andy; Fouhy, Fiona; Clarke, Siobhan F; Marques, Tatiana M; O'Toole, Paul W; Stanton, Catherine; Quigley, Eamonn M M; Daly, Charlie; Ross, Paul R; O'Doherty, Robert M; Shanahan, Fergus

    2013-02-01

    The gut microbiota is an environmental regulator of fat storage and adiposity. Whether the microbiota represents a realistic therapeutic target for improving metabolic health is unclear. This study explored two antimicrobial strategies for their impact on metabolic abnormalities in murine diet-induced obesity: oral vancomycin and a bacteriocin-producing probiotic (Lactobacillus salivarius UCC118 Bac(+)). Male (7-week-old) C57BL/J6 mice (9-10/group) were fed a low-fat (lean) or a high-fat diet for 20 weeks with/without vancomycin by gavage at 2 mg/day, or with L. salivarius UCC118Bac(+) or the bacteriocin-negative derivative L. salivarius UCC118Bac(-) (each at a dose of 1×10(9) cfu/day by gavage). Compositional analysis of the microbiota was by 16S rDNA amplicon pyrosequencing. Analysis of the gut microbiota showed that vancomycin treatment led to significant reductions in the proportions of Firmicutes and Bacteroidetes and a dramatic increase in Proteobacteria, with no change in Actinobacteria. Vancomycin-treated high-fat-fed mice gained less weight over the intervention period despite similar caloric intake, and had lower fasting blood glucose, plasma TNFα and triglyceride levels compared with diet-induced obese controls. The bacteriocin-producing probiotic had no significant impact on the proportions of Firmicutes but resulted in a relative increase in Bacteroidetes and Proteobacteria and a decrease in Actinobacteria compared with the non-bacteriocin-producing control. No improvement in metabolic profiles was observed in probiotic-fed diet-induced obese mice. Both vancomycin and the bacteriocin-producing probiotic altered the gut microbiota in diet-induced obese mice, but in distinct ways. Only vancomycin treatment resulted in an improvement in the metabolic abnormalities associated with obesity thereby establishing that while the gut microbiota is a realistic therapeutic target, the specificity of the antimicrobial agent employed is critical.

  6. Suicin 3908, a new lantibiotic produced by a strain of Streptococcus suis serotype 2 isolated from a healthy carrier pig.

    Directory of Open Access Journals (Sweden)

    Katy Vaillancourt

    Full Text Available While Streptococcus suis serotype 2 is known to cause severe infections in pigs, it can also be isolated from the tonsils of healthy animals that do not develop infections. We hypothesized that S. suis strains in healthy carrier pigs may have the ability to produce bacteriocins, which may contribute to preventing infections by pathogenic S. suis strains. Two of ten S. suis serotype 2 strains isolated from healthy carrier pigs exhibited antibacterial activity against pathogenic S. suis isolates. The bacteriocin produced by S. suis 3908 was purified to homogeneity using a three-step procedure: ammonium sulfate precipitation, cationic exchange HPLC, and reversed-phase HPLC. The bacteriocin, called suicin 3908, had a low molecular mass; was resistant to heat, pH, and protease treatments; and possessed membrane permeabilization activity. Additive effects were obtained when suicin 3908 was used in combination with penicillin G or amoxicillin. The amino acid sequence of suicin 3908 suggested that it is lantibiotic-related and made it possible to identify a bacteriocin locus in the genome of S. suis D12. The putative gene cluster involved in suicin production by S. suis 3908 was amplified by PCR, and the sequence analysis revealed the presence of nine open reading frames (ORFs, including the structural gene and those required for the modification of amino acids, export, regulation, and immunity. Suicin 3908, which is encoded by the suiA gene, exhibited approximately 50% identity with bovicin HJ50 (Streptococcus bovis, thermophilin 1277 (Streptococcus thermophilus, and macedovicin (Streptococcus macedonicus. Given that S. suis 3908 cannot cause infections in animal models, that it is susceptible to conventional antibiotics, and that it produces a bacteriocin with antibacterial activity against all pathogenic S. suis strains tested, it could potentially be used to prevent infections and to reduce antibiotic use by the swine industry.

  7. Stability of enterocin AS-48 in fruit and vegetable juices.

    Science.gov (United States)

    Grande, Maria J; Lucas, Rosario; Valdivia, Eva; Abriouel, Hikmate; Maqueda, Mercedes; Omar, Nabil Ben; Martínez-Cañamero, Magdalena; Gálvezi, Antonio

    2005-10-01

    Enterocin AS-48 is a candidate bacteriocin for food biopreservation. Before addressing application of AS-48 to vegetable-based foods, the interaction between AS-48 and vegetable food components and the stability of AS-48 were studied. Enterocin AS-48 had variable interactions with fruit and vegetable juices, with complete, partial, or negligible loss of activity. For some juices, loss of activity was ameliorated by increasing the bacteriocin concentration, diluting the juice, or applying a heat pretreatment. In juices obtained from cabbage, cauliflower, lettuce, green beans, celery, and avocado, AS-48 was very stable for the first 24 to 48 h of storage under refrigeration, and decay of activity was markedly influenced by storage temperature. In fresh-made fruit juices (orange, apple, grapefruit, pear, pineapple, and kiwi) and juice mixtures, AS-48 was very stable for at least 15 days at 4 degrees C, and bacteriocin activity was still detectable after 30 days of storage. Gradual and variable loss of activity occurred in juices stored at 15 and 28 degrees C; inactivation was faster at higher temperatures. In commercial fruit juices (orange, apple, peach, and pineapple) stored at 4 degrees C, the bacteriocin was completely stable for up to 120 days, and over 60% of initial activity was still present in juices stored at 15 degrees C for the same period. Commercial fruit juices stored at 28 degrees C for 120 days retained between 31.5% (apple) and 67.71% (peach) of their initial bacteriocin activity. Solutions of AS-48 in sterile distilled water were stable (120 days at 4 to 28 degrees C). Limited loss of activity was observed after mixing AS-48 with some food-grade dyes and thickening agents. Enterocin AS-48 added to lettuce juice incubated at 15 degrees C reduced viable counts of Listeria monocytogenes CECT 4032 and Bacillus cereus LWL1 to below detection limits and markedly reduced viable counts of Staphylococcus aureus CECT 976.

  8. In Vitro Evaluation of Beneficial Properties of Bacteriocinogenic Lactobacillus plantarum ST8Sh.

    Science.gov (United States)

    Todorov, Svetoslav Dimitrov; Holzapfel, Wilhelm; Nero, Luis Augusto

    2017-06-01

    Lactobacillus plantarum ST8Sh, isolated from Bulgarian salami "shpek" and previously characterized as bacteriocin producer, was evaluated for its beneficial properties. Based on the PCR analysis, Lb. plantarum ST8Sh was shown to host a gene related to the production of adhesion proteins such as Mab, Mub, EF, and PrgB. Genetic and physiological tests suggest Lb. plantarum ST8Sh to represent a potential probiotic candidate, including survival in the presence of low levels of pH and high levels of ox bile, production of β-galactosidase, bile salt deconjugation, high level of hydrophobicity, functional auto- and co-aggregation properties, and adhesion to cell lines. Application of semi-purified bacteriocin produced by Lb. plantarum ST8Sh in combination with ciprofloxacin presented synergistic effect on inhibition of Listeria monocytogenes Scott A. Based on observed properties, Lb. plantarum ST8Sh can be considered as a potential probiotic candidate with additional bacteriocinogenic properties.

  9. Nisin and its Antimicrobial Effect in Foods

    Directory of Open Access Journals (Sweden)

    Hamparsun Hampikyan

    2007-04-01

    Full Text Available Nisin is a bacteriocin which is produced by Lactococcus lactis and takes its place in I. class bacteriocins which are known as lantibiotics. Nisin has antimicrobial and bactericidal activity against a broad spectrum of gram positive bacteria and spores of Clostridium spp. and Bacillus spp. According to toxicity studies nisin is considered not toxic to humans. Its first established used was as a preservative in processed cheese products and since than numerous other applications in various foods such as meat and meat products, poultry products, sea products and beverages such as beer, wine have been used safely. In this review, the characteristics of nisin, its usage in food and its antimicrobial effect are considered. [TAF Prev Med Bull. 2007; 6(2: 142-147

  10. Nisin and its Antimicrobial Effect in Foods

    Directory of Open Access Journals (Sweden)

    Hamparsun Hampikyan

    2007-04-01

    Full Text Available Nisin is a bacteriocin which is produced by Lactococcus lactis and takes its place in I. class bacteriocins which are known as lantibiotics. Nisin has antimicrobial and bactericidal activity against a broad spectrum of gram positive bacteria and spores of Clostridium spp. and Bacillus spp. According to toxicity studies nisin is considered not toxic to humans. Its first established used was as a preservative in processed cheese products and since than numerous other applications in various foods such as meat and meat products, poultry products, sea products and beverages such as beer, wine have been used safely. In this review, the characteristics of nisin, its usage in food and its antimicrobial effect are considered. [TAF Prev Med Bull 2007; 6(2.000: 142-147

  11. Intracellular pH of Mycobacterium avium subsp. paratuberculosis following exposure to antimicrobial compounds monitored at the single cell level

    DEFF Research Database (Denmark)

    Gaggìa, Francesca; Nielsen, Dennis Sandris; Biavati, Bruno

    2010-01-01

    H(i)) of one strain of MAP after exposure to nisin and neutralized cell-free supernatants (NCSs) from five bacteriocin-producing lactic acid bacteria (LAB) with known probiotic properties. The evaluation of pH(i) by FRIM provides information about the physiological state of bacterial cells, bypassing the long...... and problematic incubations needed for methods relying upon growth of MAP such as determination of colony forming units. The FRIM results showed that both nisin and the cell-free supernatant from Lactobacillus plantarum PCA 236 affected the pH(i) of MAP within a few hours. However, monitoring the population...... for 24h revealed the presence of a subpopulation of cells probably resistant to the antimicrobial compounds tested. Use of nisin and bacteriocin-producing LAB strains could lead to new intervention strategies for the control of MAP based on in vivo application of probiotic cultures as feed additives...

  12. Lactobacillus plantarum inhibits growth of Listeria monocytogenes in an in vitro continuous flow gut model, but promotes invasion of L. monocytogenes in the gut of gnotobiotic rats

    DEFF Research Database (Denmark)

    Bernbom, Nete; Licht, Tine Rask; Saadbye, Peter

    2006-01-01

    The ability of the pediocin AcH producing Lactobacillus plantarum DDEN 11007 and its non-producing plasmid-cured isogenic variant, DDEN 12305 to prevent the persistence and growth of Listeria monocytogenes EP2 in two gastrointestinal (GI) tract models was examined. In vitro studies conducted...... in a two-stage continuous flow system showed that L. plantarum DDEN 11007 inhibited L. monocytogenes EP2 under these conditions, while less effect was seen of the non-bacteriocin producing variant. The inhibitory effect was more pronounced at pH 5 than at pH 7. No effect on persistence of L. monocytogenes...... in the GI tract was seen in gnotobiotic rats colonized with either the pediocin AcH producing or the non-bacteriocin producing variant of L. plantarum when compared to rats inoculated with L. monocytogenes EP2 alone. Surprisingly, inoculation of the gnotobiotic animals with either of the L. plantarum...

  13. Antimicrobial activities of Rhizobium sp. strains against Pseudomonas savastanoi, the agent responsible for the olive knot disease in Algeria

    Energy Technology Data Exchange (ETDEWEB)

    Mourad, K.; Fadhila, K.; Chahinez, M.; Merien, R.; Philippe, L. de; Abdelkader, B.

    2009-07-01

    In the present investigation, six Rhizobium strains isolated from Algerian soil were checked for their antimicrobial activity against Pseudomonas savastanoi, the agent responsible for olive knot disease. Rhizobium sp. ORN 24 and ORN 83 were found to produce antimicrobial activities against Pseudomonas savastanoi. The antimicrobial activity produced by Rhizobium sp. ORN24 was precipitable with ammonium sulfate, between 1,000 and 10,000 KDa molecular weight, heat resistant but sensitive to proteases and detergents. These characteristics suggest the bacteriocin nature of the antimicrobial substance produced by Rhizobium sp. ORN24, named rhizobiocin 24. In contrast, the antimicrobial activity produced by Rhizobium sp. ORN83 was not precipitable with ammonium sulfate; it was smaller than 1,000 KDa molecular weight, heat labile, and protease and detergent resistant. These characteristics could indicate the relationship between the antimicrobial substance produced by Rhizobium sp. ORN 83 and the small bacteriocins described in other rhizobia. (Author) 51 refs.

  14. Genome Sequence of Vibrio campbellii Strain UMTGB204, a Marine Bacterium Isolated from a Green Barrel Tunicate

    Science.gov (United States)

    Gan, Huan You; Noor, Mohd Ezhar Mohd; Saari, Nur Azna; Musa, Najiah; Mustapha, Baharim; Usup, Gires

    2015-01-01

    Vibrio campbellii strain UMTGB204 was isolated from a green barrel tunicate. The genome of this strain comprises 5,652,224 bp with 5,014 open reading frames, 9 rRNAs, and 116 tRNAs. It contains genes related to virulence and environmental tolerance. Gene clusters for the biosynthesis of nonribosomal peptides and bacteriocin were also identified. PMID:25814609

  15. LACTIC ACID BACTERIA: PROBIOTIC APPLICATIONS

    OpenAIRE

    NEENA GARG

    2015-01-01

    Lactic acid bacteria (LAB) is a heterotrophic Gram-positive bacteria which under goes lactic acid fermentations and leads to production of lactic acid as an end product. LAB includes Lactobacillus, Leuconostoc, Pediococcus, Lactococcus and Streptococcus which are grouped together in the family lactobacillaceae. LAB shows numerous antimicrobial activities due to production of antibacterial and antifungal compounds such as organic acids, bacteriocins, diacetyl, hydrogen peroxide and reutrin. LA...

  16. Complete genome sequence of Lactobacillus paracasei CAUH35, a new strain isolated from traditional fermented dairy product koumiss in China.

    Science.gov (United States)

    Wang, Guohong; Xiong, Yao; Xu, Qi; Yin, Jia; Hao, Yanling

    2015-11-20

    Lactobacillus paracasei CAUH35 was isolated from homemade koumiss, a traditional fermented dairy product with beneficial effects on human health. The genome consists of a circular 2,770,411 bp chromosome and four plasmids. Genome analysis revealed the presence of gene clusters involved in the production of exopolysaccharides and bacteriocin. The complete genome sequence of L. paracasei CAUH35 will provide genetic basis for further comparative and functional genomic analyses. Copyright © 2015. Published by Elsevier B.V.

  17. Isolation and characterization of bacteriocinogenic lactic bacteria from M-Tuba and Tepache, two traditional fermented beverages in México

    OpenAIRE

    de la Fuente-Salcido, Norma M; Castañeda-Ramírez, José Cristobal; García-Almendárez, Blanca E; Bideshi, Dennis K; Salcedo-Hernández, Rubén; Barboza-Corona, José E

    2015-01-01

    Mexican Tuba (M-Tuba) and Tepache are Mexican fermented beverages prepared mainly with pineapple pulp and coconut palm, respectively. At present, reports on the microbiota and nutritional effects of both beverages are lacking. The purpose of this study was to determine whether M-Tuba and Tepache contain cultivable lactic acid bacteria (LAB) capable of producing bacteriocins. Tepache and M-Tuba contain mesophilic aerobic bacteria, LAB, and yeast. Bacillus subtilis, Listeria monocytogenes, List...

  18. Independent Co-Option of a Tailed Bacteriophage into a Killing Complex in Pseudomonas.

    Science.gov (United States)

    Hockett, Kevin L; Renner, Tanya; Baltrus, David A

    2015-08-11

    Competition between microbes is widespread in nature, especially among those that are closely related. To combat competitors, bacteria have evolved numerous protein-based systems (bacteriocins) that kill strains closely related to the producer. In characterizing the bacteriocin complement and killing spectra for the model strain Pseudomonas syringae B728a, we discovered that its activity was not linked to any predicted bacteriocin but is derived from a prophage. Instead of encoding an active prophage, this region encodes a bacteriophage-derived bacteriocin, termed an R-type syringacin. This R-type syringacin is striking in its convergence with the well-studied R-type pyocin of P. aeruginosa in both genomic location and molecular function. Genomic alignment, amino acid percent sequence identity, and phylogenetic inference all support a scenario where the R-type syringacin has been co-opted independently of the R-type pyocin. Moreover, the presence of this region is conserved among several other Pseudomonas species and thus is likely important for intermicrobial interactions throughout this important genus. Evolutionary innovation is often achieved through modification of complexes or processes for alternate purposes, termed co-option. Notable examples include the co-option of a structure functioning in locomotion (bacterial flagellum) to one functioning in protein secretion (type three secretion system). Similar co-options can occur independently in distinct lineages. We discovered a genomic region in the plant pathogen Pseudomonas syringae that consists of a fragment of a bacteriophage genome. The fragment encodes only the tail of the bacteriophage, which is lethal toward strains of this species. This structure is similar to a previously described structure produced by the related species Pseudomonas aeruginosa. The two structures, however, are not derived from the same evolutionary event. Thus, they represent independent bacteriophage co-options. The co

  19. Bacterial antagonist mediated protein molecules

    OpenAIRE

    Urbizu, Lucia Paola; Sparo, Mónica Delfina; Sanchez Bruni, Sergio Fabian

    2016-01-01

    Bacterial antagonism mediated by ribosomally synthesised peptides has gained considerable attention in recent years because of its potential applications in the control of undesirable microbiota. These peptides, generally referred to as bacteriocins, are defined as a heterogeneous group of ribosomally synthesised, proteinaceous substances (with or without further modifications) extracellularly secreted by many Gram-positive and some Gram-negative bacteria. Their mode of activity is primarily ...

  20. Improved applicability of nisin in novel combinations with other food preservation factors

    OpenAIRE

    Pol, I.E.

    2001-01-01

    General discussion

    Modern consumers nowadays, have a preference for more natural, mildly preserved food products with a fresh appearance over traditionally preserved products. Mild preservation techniques applied singly are usually not sufficient to control microbial outgrowth and combinations of measures are needed to ensure complete safe products (16). Bacteriocins, produced by lactic acid bacteria have been successfully used as biopreservatives in a number of f...

  1. Two Tales of Prokaryotic Genomic Diversity: Escherichia coli and Halophiles

    Directory of Open Access Journals (Sweden)

    Lejla Pašić

    2014-01-01

    Full Text Available Prokaryotes are generally characterized by vast genomic diversity that has been shaped by mutations, horizontal gene transfer, bacteriocins and phage predation. Enormous genetic diversity has developed as a result of stresses imposed in harsh environments and the ability of microorganisms to adapt. Two examples of prokaryotic diversity are presented: on intraspecies level, exemplified by Escherichia coli, and the diversity of the hypersaline environment, with the discussion of food-related health issues and biotechnological potential.

  2. pH-, Lactic Acid-, and Non-Lactic Acid-Dependent Activities of Probiotic Lactobacilli against Salmonella enterica Serovar Typhimurium

    OpenAIRE

    Fayol-Messaoudi, Domitille; Berger, Cédric N.; Coconnier-Polter, Marie-Hélène; Liévin-Le Moal, Vanessa; Servin, Alain L.

    2005-01-01

    The mechanism(s) underlying the antibacterial activity of probiotic Lactobacillus strains appears to be multifactorial and includes lowering of the pH and the production of lactic acid and of antibacterial compounds, including bacteriocins and nonbacteriocin, non-lactic acid molecules. Addition of Dulbecco's modified Eagle's minimum essential medium to the incubating medium delays the killing activity of lactic acid. We found that the probiotic strains Lactobacillus johnsonii La1, Lactobacill...

  3. Characterization of Pediococcus acidilactici strains isolated from rainbow trout (Oncorhynchus mykiss) feed and larvae: safety, DNA fingerprinting, and bacteriocinogenicity.

    Science.gov (United States)

    Araújo, Carlos; Muñoz-Atienza, Estefanía; Poeta, Patrícia; Igrejas, Gilberto; Hernández, Pablo E; Herranz, Carmen; Cintas, Luis M

    2016-05-03

    The use of lactic acid bacteria (LAB) as probiotics constitutes an alternative or complementary strategy to chemotherapy and vaccination for disease control in aquaculture. The objectives of this work were (1) the in vitro safety assessment of 8 Pediococcus acidilactici strains isolated from rainbow trout (Oncorhynchus mykiss, Walbaum) feed and larvae; (2) the evaluation of their genetic relatedness; (3) the study of their antimicrobial/bacteriocin activity against fish pathogens; and (4) the biochemical and genetic characterization of the bacteriocin produced by the strain displaying the greatest antimicrobial activity. Concerning the safety assessment, none of the pediococci showed antibiotic resistance nor produced hemolysin or gelatinase, degraded gastric mucin, or deconjugated bile salts. Four strains (50%) produced tyramine or putrescine, but the corresponding genes were not amplified by PCR. Enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR) fingerprinting allowed clustering of the pediococci into 2 well-defined groups (68% similarity). From the 8 pediococci displaying direct antimicrobial activity against at least 3 out of 9 fish pathogens, 6 strains (75%) were identified as bacteriocin producers. The bacteriocin produced by P. acidilactici L-14 was purified, and mass spectrometry and DNA sequencing revealed its identity to pediocin PA-1 (PedPA-1). Altogether, our results allowed the identification of 4 (50%) putatively safe pediococci, including 2 bacteriocinogenic strains. ERIC-PCR fingerprinting was a valuable tool for genetic profiling of P. acidilactici strains. This work reports for the first time the characterization of a PedPA-1-producing P. acidilactici strain isolated from an aquatic environment (rainbow trout larvae), which shows interesting properties related to its potential use as a probiotic in aquaculture.

  4. ["In vitro" study of the bacteriocinogenic capacity of Streptococcus mutans].

    Science.gov (United States)

    Baca García, P; Liébana Ureña, J; Baca García, A

    1991-06-01

    In our paper the bacteriocinogen ability of some subspecies of Streptococci mutans has been studied. We have obtained a production percentage of 50%. That production ability was bigger for subspecies mutans than sobrinus in a significative way, who strength the increasing differences between these microorganisms. A brief revision of the role that bacteriocins look like to play in oral ecologist equilibrium and their feasible utilization in dental caries prevention has been done.

  5. A Search Within the Genera Streptococcus, Enterococcus and Lactobacillus for Organisms inhibitory to Mutans Streptococci

    OpenAIRE

    James, S. M.; Tagg, J. R.

    2011-01-01

    A deferred antagonism method was used to test 181 Streptococcus, 47 Enterococcus and 49 Lactobacillus isolates for production of bacteriocin-like inhibitory activity against eight mutans streptococci indicator strains. Inhibitor testing was carried out on blood agar medium (BA) and also on BA which had been supplemented with 0.5 per cent calcium carbonate (BA + Ca) to minimise pH-related inhibitory effects due to the accumulation of acidic metabolites. The streptococci tested for anti-mutans ...

  6. Co-expression of Nisin Z and Leucocin C as a Basis for Effective Protection Against Listeria monocytogenes in Pasteurized Milk

    Directory of Open Access Journals (Sweden)

    Yuxin Fu

    2018-03-01

    Full Text Available Nisin, an important bacteriocin from Lactococcus lactis subsp., is primarily active against various Gram-positive bacteria. Leucocin C, produced by Leuconostoc carnosum 4010, is a class IIa bacteriocin used to inhibit the growth of Listeria monocytogenes. Because two bacteriocins have different modes of action, the combined use of them could be a potential strategy for effective inhibition of foodborne pathogens. In this study, L. lactis N8-r-lecCI (N8 harboring lecCI gene coexpressing nisin–leucocin C was constructed based on the food-grade carrier L. lactis N8. Production of both bacteriocins was stably maintained. Antimicrobial measurements showed that the recombinant strain is effectively against Listeria monocytogenes and Staphylococcus aureus and moderately against Salmonella enterica serovar Enteritidis and Escherichia coli because of its stronger antibacterial activity than the parental strain, this result first demonstrated that the co-expression of nisin and leucocin C results in highly efficient antimicrobial activity. The checkerboard assay showed that the antibacterial activity of L. lactis N8-r-lecCI supernatant was enhanced in the presence of low concentration of EDTA. Analysis of the scanning electron microscope image showed the biggest cellular morphology change in L. monocytogenes treated with a mixture of EDTA and L. lactis N8-r-lecCI supernatant. The practical effect was verified in pasteurized milk through time-kill assay. The L. lactis N8-r-lecCI strain expressing both nisin and leucocin C has a promising application prospect in pasteurized milk processing and preservation because of its strong antibacterial activity.

  7. New lantibiotics from cyanobacteria

    OpenAIRE

    Yang, Jiahui Jr

    2016-01-01

    Lantibiotics are a subgroup of bacteriocins, produced by Gram-positive bacteria to inhibit the growth of closely related strains. They are used as food preservatives e.g. nisin, and some are in clinical trials, e.g. duramycin A and microbisporicin. Cinnamycin is a 19 amino acid lantibiotic that inhibits the growth of Gram-positive rods. Recent work suggests that cyanobacteria might be able to make variants of cinnamycin. Here I determined the product of a cinnamycin biosynthetic pathway prese...

  8. Genomic analysis of a Streptococcus pyogenes strain causing endocarditis in a child

    Directory of Open Access Journals (Sweden)

    M. Beye

    2017-05-01

    Full Text Available We sequenced the genome of Streptococcus pyogenes strain G773 that caused an infective endocarditis in a 4-year-old boy suffering from acute endocarditis. The 1.9-Mb genome exhibited a specific combination of virulence factors including a complete integrative and conjugative element, sp2905, previously described as incomplete in S. pyogenes, and five bacteriocin-coding genes. However, strain G773 lacked a CRISPR-Cas system.

  9. Characterization of a Multipeptide Lantibiotic Locus in Streptococcus pneumoniae

    Directory of Open Access Journals (Sweden)

    Natalie Maricic

    2016-01-01

    Full Text Available Bacterial communities are established through a combination of cooperative and antagonistic interactions between the inhabitants. Competitive interactions often involve the production of antimicrobial substances, including bacteriocins, which are small antimicrobial peptides that target other community members. Despite the nearly ubiquitous presence of bacteriocin-encoding loci, inhibitory activity has been attributed to only a small fraction of gene clusters. In this study, we characterized a novel locus (the pld locus in the pathogen Streptococcus pneumoniae that drives the production of a bacteriocin called pneumolancidin, which has broad antimicrobial activity. The locus encodes an unusual tandem array of four inhibitory peptides, three of which are absolutely required for antibacterial activity. The three peptide sequences are similar but appear to play distinct roles in regulation and inhibition. A modification enzyme typically found in loci encoding a class of highly modified bacteriocins called lantibiotics was required for inhibitory activity. The production of pneumolancidin is controlled by a two-component regulatory system that is activated by the accumulation of modified peptides. The locus is located on a mobile element that has been found in many pneumococcal lineages, although not all elements carry the pld genes. Intriguingly, a minimal region containing only the genes required for pneumolancidin immunity was found in several Streptococcus mitis strains. The pneumolancidin-producing strain can inhibit nearly all pneumococci tested to date and provided a competitive advantage in vivo. These peptides not only represent a unique strategy for bacterial competition but also are an important resource to guide the development of new antimicrobials.

  10. Physicochemical and hygienic effects of Lactobacillus acidophilus in Iranian white cheese

    OpenAIRE

    Mahmoudi, Razzaqh; Tajik, Hossein; Ehsani, Ali; Zare, Payman

    2012-01-01

    Increasing incidence of food-borne disease along with its social and economic consequences have led to conducting extensive research in order to produce safer food and develop new antimicrobial agents; among them, extensive use of probiotics and bacteriocins as biological additives is of significant importance. The aim of the present study was to evaluate the interactions (growth behavior and survival) of Listeria monocytogenes and Lactobacillus acidophilus in various stages of production, ri...

  11. Draft Genome Sequences of Bacillus cereus E41 and Bacillus anthracis F34 Isolated from Algerian Salt Lakes

    Science.gov (United States)

    Daas, Mohamed Seghir; Rosana, Albert Remus R.; Acedo, Jeella Z.; Nateche, Farida; Kebbouche-Gana, Salima; Vederas, John C.

    2017-01-01

    ABSTRACT Two strains of Bacillus, B. cereus E41 and B. anthracis F34, were isolated from a salt lake in Aïn M’lila-Oum El Bouaghi, eastern Algeria, and Ain Baida-Ouargla, southern Algeria, respectively. Their genomes display genes for the production of several bioactive secondary metabolites, including polyhydroxyalkanoate, iron siderophores, lipopeptides, and bacteriocins. PMID:28522726

  12. Draft Genome Sequence of Bacillus velezensis B6, a Rhizobacterium That Can Control Plant Diseases.

    Science.gov (United States)

    Gao, Yu-Han; Guo, Rong-Jun; Li, Shi-Dong

    2018-03-22

    The draft genome of Bacillus velezensis strain B6, a rhizobacterium with good biocontrol performance isolated from soil in China, was sequenced. The assembly comprises 32 scaffolds with a total size of 3.88 Mb. Gene clusters coding either ribosomally encoded bacteriocins or nonribosomally encoded antimicrobial polyketides and lipopeptides in the genome may contribute to plant disease control. Copyright © 2018 Gao et al.

  13. Study of vancomycin resistance in faecal enterococci from healthy humans and dogs in Spain a decade after the avoparcin ban in Europe.

    Science.gov (United States)

    López, M; Tenorio, C; Torres, C

    2013-03-01

    One hundred and 26 faecal samples from healthy dogs (2009) and 157 faecal samples from healthy humans (2007) from La Rioja region (Spain) were tested to know the carriage of vancomycin-resistant enterococci (VRE). VRE with intrinsic resistance (vanC) were found in 12% of healthy dogs and humans (29 Enterococcus gallinarum and four Enterococcus casseliflavus). Nevertheless, VRE with acquired mechanism of resistance were not detected among these samples. Four Enterococcus faecalis isolates with vancomycin MIC of 8-16 mg L(-1) were recovered in human samples, but no single organism with known mechanism of acquired resistance could be identified. These 37 VRE isolates (33 E. gallinarum/E. casseliflavus and four E. faecalis) of dog and human origin were further characterized (PCR detection of antibiotic resistance, virulence and bacteriocin genes). High prevalence of tetracycline resistance was identified (70%), especially among dog isolates harbouring tet(M) ± tet(L) genes; erythromycin resistance was also higher among isolates from dogs and they harboured the erm(B) gene, associated with erm(A) gene in one case. Virulence genes were only identified among E. faecalis isolates of human origin (agg, cpd and/or gelE) and never among E. gallinarum/E. casseliflavus of human or dog origin. Five E. gallinarum isolates of dog and three E. faecalis of human origin expressed bacteriocin activity; among them, only one E. faecalis presented activity against Listeria monocytogenes. The bacteriocin structural gene ef1097 was identified in 3 bacteriocin-producing E. faecalis isolates, associated with ent1071 in one of them. © 2012 Blackwell Verlag GmbH.

  14. Isolation, Characterization and Identification of Environmental Bacterial Isolates with Screening for Antagonism Against Three Bacterial Targets

    Science.gov (United States)

    2017-04-01

    making the broad-spectrum antimicrobial ineffective. When this occurs, the current strategy is to replace an ineffective antimicrobial agent with...Shlae. “Fix the Antibiotic Pipeline ”. Nature 472:32. (2011) Cotter, P.A., C. Hin, and R.P. Ross. “Bacteriocin Developing Innate Immunity for Food...and resistance. Clin. Microbiol. Rev. 12:147—179. (1999) Silver, S. “Bacterial silver resistance: molecular biology and uses and misuses of silver

  15. The Impact of the Antimicrobial Compounds Produced by Lactic Acid Bacteria on the Growth Performance of Mycobacterium avium subsp. paratuberculosis

    Directory of Open Access Journals (Sweden)

    Petr Kralik

    2018-04-01

    Full Text Available Cell-free supernatants (CFSs extracted from various lactic acid bacteria (LAB cultures were applied to Mycobacterium avium subsp. paratuberculosis (MAP cells to determine their effect on MAP viability. In addition, 5% lactic acid (LA; pH 3 and commercially synthetized nisin bacteriocin were also tested. This procedure was chosen in order to mimic the influence of LAB compounds during the production and storage of fermented milk products, which can be contaminated by MAP. Its presence in milk and milk products is of public concern due to the possible ingestion of MAP by consumers and the discussed role of MAP in Crohn’s disease. Propidium monoazide real-time PCR (PMA qPCR was used for viability determination. Although all CFS showed significant effects on MAP viability, two distinct groups of CFS – effective and less effective – could be distinguished. The effective CFSs were extracted from various lactobacilli cultures, their pH values were mostly lower than 4.5, and their application resulted in >2 log10 reductions in MAP viability. The group of less effective CFS were filtered from Lactococcus and enterococci cultures, their pH values were higher than 4.5, and their effect on MAP viability was <2 log10. LA elicited a reduction in MAP viability that was similar to that of the group of less effective CFS. Almost no effect was found when using commercially synthetized nisin at concentrations of 0.1–1000 μg/ml. A combination of the influence of the type of bacteriocin, the length of its action, bacteriocin production strain, and pH are all probably required for a successful reduction in MAP viability. However, certain bacteriocins and their respective LAB strains (Lactobacillus sp. appear to play a greater role in reducing the viability of MAP than pH.

  16. Impact of Lactobacillus curvatus 54M16 on microbiota composition and growth of Listeria monocytogenes in fermented sausages.

    Science.gov (United States)

    Giello, Marina; La Storia, Antonietta; De Filippis, Francesca; Ercolini, Danilo; Villani, Francesco

    2018-06-01

    Lactobacillus curvatus 54M16 produced bacteriocins sak X, sak T α , sak T β and sak P. The aim of this study was to investigate the anti-listerial activity of the bacteriocins-producing strain against Listeria monocytogenes in vitro co-culture experiments and during the manufacture of fermented sausages. In MRS broth, Lb. curvatus 54M16 was able to inhibit L. monocytogenes to undetectable levels after 48 h at 20 °C or 5 days at 15 °C. Anti-listerial activity was lower during the production of fermented sausages with pathogen inoculation at levels of approximately 4 Log CFU g -1 . However, total inhibition of L. monocytogenes native to the raw ingredients was achieved over the course of the fermentation. Moreover, 16S rRNA-based analysis revealed the ability of Lb. curvatus 54M16 to dominate and affect the bacterial ecosystem, whereas spoilage-associated bacterial genera, such as Brochothrix, Psychrobacter, Pseudomonas and some Enterobacteriaceae, were found until the end of ripening in sausages without Lb. curvatus 54M16. The use of the bacteriocins-producing Lb. curvatus 54M16 in fermented sausages could be an important contribution to product safety, provided that eco-physiological factors and other preservation methods are maintained at levels required for the inhibition of pathogens in controlled conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. The Cyclic Antibacterial Peptide Enterocin AS-48: Isolation, Mode of Action, and Possible Food Applications

    Directory of Open Access Journals (Sweden)

    María José Grande Burgos

    2014-12-01

    Full Text Available Enterocin AS-48 is a circular bacteriocin produced by Enterococcus. It contains a 70 amino acid-residue chain circularized by a head-to-tail peptide bond. The conformation of enterocin AS-48 is arranged into five alpha-helices with a compact globular structure. Enterocin AS-48 has a wide inhibitory spectrum on Gram-positive bacteria. Sensitivity of Gram-negative bacteria increases in combination with outer-membrane permeabilizing treatments. Eukaryotic cells are bacteriocin-resistant. This cationic peptide inserts into bacterial membranes and causes membrane permeabilization, leading ultimately to cell death. Microarray analysis revealed sets of up-regulated and down-regulated genes in Bacillus cereus cells treated with sublethal bacteriocin concentration. Enterocin AS-48 can be purified in two steps or prepared as lyophilized powder from cultures in whey-based substrates. The potential applications of enterocin AS-48 as a food biopreservative have been corroborated against foodborne pathogens and/or toxigenic bacteria (Listeria monocytogenes, Bacillus cereus, Staphylococcus aureus, Escherichia coli, Salmonella enterica and spoilage bacteria (Alicyclobacillus acidoterrestris, Bacillus spp., Paenibacillus spp., Geobacillus stearothermophilus, Brochothrix thermosphacta, Staphylococcus carnosus, Lactobacillus sakei and other spoilage lactic acid bacteria. The efficacy of enterocin AS-48 in food systems increases greatly in combination with chemical preservatives, essential oils, phenolic compounds, and physico-chemical treatments such as sublethal heat, high-intensity pulsed-electric fields or high hydrostatic pressure.

  18. Action des cultures protectrices : cas des germes lactiques sur la flore alimentaire indésirable

    Directory of Open Access Journals (Sweden)

    Privat, K.

    2011-01-01

    Full Text Available Protective action of cultures: the case of lactic bacteria against undesirable food flora. Protective strains have been used for centuries in the fermentation of a variety of food. The preservative ability of these strains in food is attributed to the production of antimicrobial metabolites including organic acids and bacteriocins. But to secure an extension of shelf life and better food safety, the multiple antimicrobial barriers approach is required. This approach typically uses the principal hurdles temperature (higher or lower, water activity (Aw, pH, redox potentiel (Eh, chemical preservatives, vacuum packaging, modified atmosphere, high hydrostatic pressure (HHP and UV, as additional barriers to protective cultures and/or antimicrobial compounds. This paper reviews the recent literature describing the protective cultures and different ways they use to suppress unwanted flora. Are also briefly presented, classification, biosynthesis, mechanism of action of bacteriocins produced by these cultures and finally the protective benefit of using additional barriers to booster protective cultures and/or their bacteriocins.

  19. Les produits de la mer au Sénégal et le potentiel des bactéries lactiques et des bactériocines pour la conservation

    Directory of Open Access Journals (Sweden)

    Diop, MB.

    2010-01-01

    Full Text Available Fish preservation in Senegal: potential use of lactic acid bacteria and their antibacterial metabolites. In Senegal, fish are first as staple animal protein foods for populations. Socioeconomic constraints hamper the development of industrial preservations. Traditional fish production has some inherent food safety concerns considering the high susceptibility of seafood to bacterial spoilage. Some strategies of seafood products preservation using lactic acid bacteria producing bacteriocin are not very expensive and do not consume energy very much. They can be adapted in the preservation of fish in Senegal particularly in the fermentation in which the catches, generally handled for many hours at ambient temperature, are only added salt (NaCl and sun dried. Lactic acid bacteria producing bacteriocins could be used as starters (with addition of carbohydrates during the preparation of fish for rendering them more resistant to the growth of spoilage and pathogenic bacteria by in situ production of organic acids and bacteriocins. A second alternative of application of these bacteria is to use bactericidal solutions obtained from their cultures as additional barrier to sodium chloride to prevent growth of the flora during fish storage for maturation. These new strategies of preparation combined with drying can be used to enhance microbiological and dietetic qualities of local seafood commodities.

  20. A designated centre for people with disabilities operated by Muiríosa Foundation, Westmeath

    LENUS (Irish Health Repository)

    2011-08-30

    Abstract Lactobacillus plantarum LMG P-26358 isolated from a soft French artisanal cheese produces a potent class IIa bacteriocin with 100% homology to plantaricin 423 and bacteriocidal activity against Listeria innocua and Listeria monocytogenes. The bacteriocin was found to be highly stable at temperatures as high as 100°C and pH ranges from 1-10. While this relatively narrow spectrum bacteriocin also exhibited antimicrobial activity against species of enterococci, it did not inhibit dairy starters including lactococci and lactobacilli when tested by well diffusion assay (WDA). In order to test the suitability of Lb. plantarum LMG P-26358 as an anti-listerial adjunct with nisin-producing lactococci, laboratory-scale cheeses were manufactured. Results indicated that combining Lb. plantarum LMG P-26358 (at 108 colony forming units (cfu)\\/ml) with a nisin producer is an effective strategy to eliminate the biological indicator strain, L. innocua. Moreover, industrial-scale cheeses also demonstrated that Lb. plantarum LMG P-26358 was much more effective than the nisin producer alone for protection against the indicator. MALDI-TOF mass spectrometry confirmed the presence of plantaricin 423 and nisin in the appropriate cheeses over an 18 week ripening period. A spray-dried fermentate of Lb. plantarum LMG P-26358 also demonstrated potent anti-listerial activity in vitro using L. innocua. Overall, the results suggest that Lb. plantarum LMG P-26358 is a suitable adjunct for use with nisin-producing cultures to improve the safety and quality of dairy products.

  1. Isolation and characterization of bacteriocinogenic lactic bacteria from M-Tuba and Tepache, two traditional fermented beverages in México.

    Science.gov (United States)

    de la Fuente-Salcido, Norma M; Castañeda-Ramírez, José Cristobal; García-Almendárez, Blanca E; Bideshi, Dennis K; Salcedo-Hernández, Rubén; Barboza-Corona, José E

    2015-09-01

    Mexican Tuba (M-Tuba) and Tepache are Mexican fermented beverages prepared mainly with pineapple pulp and coconut palm, respectively. At present, reports on the microbiota and nutritional effects of both beverages are lacking. The purpose of this study was to determine whether M-Tuba and Tepache contain cultivable lactic acid bacteria (LAB) capable of producing bacteriocins. Tepache and M-Tuba contain mesophilic aerobic bacteria, LAB, and yeast. Bacillus subtilis, Listeria monocytogenes, Listeria innocua, Streptococcus agalactiae, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Salmonella typhimurium, and Salmonella spp, were the microorganisms most susceptible to metabolites produced by bacterial isolates. M-Tuba and Tepache contain bacteria that harbor genes coding for nisin and enterocin, but not pediocin. The presence of Lactococcus lactis and E. faecium in M-Tuba and Tepache, was identified by 16S rDNA. These bacteria produced bacteriocins of ∼3.5 kDa and 4.0-4.5 kDa, respectively. Partial purified bacteriocins showed inhibitory effect against Micrococcus luteus, L. monocytogenes, L. innocua, Str. agalactiae, S. aureus, Bacillus cereus, B. subtilis, E. faecalis, and K. pneumoniae. We characterized, for the first time, cultivable microbiota of M-Tuba and Tepache, and specifically, identified candidate lactic bacteria (LAB) present in these beverages that were capable of synthesizing antimicrobial peptides, which collectively could provide food preservative functions.

  2. St. Joseph's Unit, Bantry General Hospital, Bantry, Cork.

    LENUS (Irish Health Repository)

    2011-08-30

    Abstract Lactobacillus plantarum LMG P-26358 isolated from a soft French artisanal cheese produces a potent class IIa bacteriocin with 100% homology to plantaricin 423 and bacteriocidal activity against Listeria innocua and Listeria monocytogenes. The bacteriocin was found to be highly stable at temperatures as high as 100°C and pH ranges from 1-10. While this relatively narrow spectrum bacteriocin also exhibited antimicrobial activity against species of enterococci, it did not inhibit dairy starters including lactococci and lactobacilli when tested by well diffusion assay (WDA). In order to test the suitability of Lb. plantarum LMG P-26358 as an anti-listerial adjunct with nisin-producing lactococci, laboratory-scale cheeses were manufactured. Results indicated that combining Lb. plantarum LMG P-26358 (at 108 colony forming units (cfu)\\/ml) with a nisin producer is an effective strategy to eliminate the biological indicator strain, L. innocua. Moreover, industrial-scale cheeses also demonstrated that Lb. plantarum LMG P-26358 was much more effective than the nisin producer alone for protection against the indicator. MALDI-TOF mass spectrometry confirmed the presence of plantaricin 423 and nisin in the appropriate cheeses over an 18 week ripening period. A spray-dried fermentate of Lb. plantarum LMG P-26358 also demonstrated potent anti-listerial activity in vitro using L. innocua. Overall, the results suggest that Lb. plantarum LMG P-26358 is a suitable adjunct for use with nisin-producing cultures to improve the safety and quality of dairy products.

  3. Assay of enterocin AS-48 for inhibition of foodborne pathogens in desserts.

    Science.gov (United States)

    Martinez Viedma, Pilar; Abriouel, Hikmate; Ben Omar, Nabil; Lucas López, Rosario; Valdivia, Eva; Gálvez, Antonio

    2009-08-01

    Enterocin AS-48 was tested against Staphylococcus aureus, Bacillus cereus, and Listeria monocytogenes in different kinds of desserts. The highest activity against S. aureus was detected in baker cream. However, in yogurt-type soy-based desserts and in gelatin pudding, AS-48 (175 arbitrary units [AU]/g) reduced viable cell counts of S. aureus by only 1.5 to 1.8 log units at most. The efficacy of AS-48 in puddings greatly depended on inoculum size, and viable S. aureus counts decreased below detection levels within 24 h for inocula lower than 4 to 5.5 log CFU/g. For L. monocytogenes, bacteriocin concentrations of 52.5 to 87.5 AU/g reduced viable counts below detection levels and avoided regrowth of survivors. The lowest activity was detected in yogurt-type desserts. For B. cereus, viable cell counts were reduced below detection levels for bacteriocin concentrations of 52.5 AU/g in instant pudding without soy or by 175 AU/g in the soy pudding. In gelatin pudding, AS-48 (175 AU/g) reduced viable cell counts of B. cereus below detection levels after 8 h at 10 degrees C or after 48 h at 22 degrees C. Bacteriocin addition also inhibited gelatin liquefaction caused by the proteolytic activity of B. cereus.

  4. 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

  5. LnqR, a TetR-family transcriptional regulator, positively regulates lacticin Q production in Lactococcus lactis QU 5.

    Science.gov (United States)

    Iwatani, Shun; Ishibashi, Naoki; Flores, Floirendo P; Zendo, Takeshi; Nakayama, Jiro; Sonomoto, Kenji

    2016-09-01

    Lacticin Q is an unmodified leaderless bacteriocin produced by Lactococcus lactis QU 5. It has been revealed that the production and self-immunity of lacticin Q are facilitated by a gene cluster lnqQBCDEF The gene for a putative TetR-family transcriptional regulator, termed lnqR, was found nearby the lnqQBCDEF cluster, but its involvement in lacticin Q biosynthesis remained unknown. In this study, we created an LnqR-overexpressing QU 5 recombinant by using lactococcal constitutive promoter P32 The recombinant QU 5 showed enhanced production of and self-immunity to lacticin Q. RT-PCR analysis has revealed that an overexpression of LnqR increases the amounts of lnqQBCDEF transcripts, and these six genes are transcribed as an operon in a single transcriptional unit. Interestingly, LnqR expression and thus lacticin Q production by L. lactis QU 5 was found temperature dependent, while LnzR, an LnqR-homologue, in L. lactis QU 14 was expressed in a similar but not identical manner to LnqR, resulting in dissimilar bacteriocin productivities by these strains. This report demonstrates LnqR as the first TetR-family transcriptional regulator involved in LAB bacteriocin biosynthesis and that, as an exceptional case of TetR-family regulators, LnqR positively regulates the transcription of these biosynthetic genes. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. Inhibitory activity of Lactobacillus plantarum LMG P-26358 against Listeria innocua when used as an adjunct starter in the manufacture of cheese

    LENUS (Irish Health Repository)

    2011-08-30

    Abstract Lactobacillus plantarum LMG P-26358 isolated from a soft French artisanal cheese produces a potent class IIa bacteriocin with 100% homology to plantaricin 423 and bacteriocidal activity against Listeria innocua and Listeria monocytogenes. The bacteriocin was found to be highly stable at temperatures as high as 100°C and pH ranges from 1-10. While this relatively narrow spectrum bacteriocin also exhibited antimicrobial activity against species of enterococci, it did not inhibit dairy starters including lactococci and lactobacilli when tested by well diffusion assay (WDA). In order to test the suitability of Lb. plantarum LMG P-26358 as an anti-listerial adjunct with nisin-producing lactococci, laboratory-scale cheeses were manufactured. Results indicated that combining Lb. plantarum LMG P-26358 (at 108 colony forming units (cfu)\\/ml) with a nisin producer is an effective strategy to eliminate the biological indicator strain, L. innocua. Moreover, industrial-scale cheeses also demonstrated that Lb. plantarum LMG P-26358 was much more effective than the nisin producer alone for protection against the indicator. MALDI-TOF mass spectrometry confirmed the presence of plantaricin 423 and nisin in the appropriate cheeses over an 18 week ripening period. A spray-dried fermentate of Lb. plantarum LMG P-26358 also demonstrated potent anti-listerial activity in vitro using L. innocua. Overall, the results suggest that Lb. plantarum LMG P-26358 is a suitable adjunct for use with nisin-producing cultures to improve the safety and quality of dairy products.

  7. Lantibiotics biosynthesis genes and bacteriocinogenic activity of Lactobacillus spp. isolated from raw milk and cheese.

    Science.gov (United States)

    Perin, Luana Martins; Moraes, Paula Mendonça; Silva, Abelardo; Nero, Luís Augusto

    2012-05-01

    Lactobacillus species are usually used as starters for the production of fermented products, and some strains are capable of producing antimicrobial substances, such as bacteriocins. Because these characteristics are highly desirable, research are continually being performed for novel Lactobacillus strains with bacteriocinogenic potential for use by food industries. The aim of this study was to characterise the bacteriocinogenic potential and activity of Lactobacillus isolates. From a lactic acid bacteria culture collection obtained from raw milk and cheese, 27 isolates were identified by 16S rDNA as Lactobacillus spp. and selected for the detection of lantibiotics biosynthesis genes, bacteriocin production, antimicrobial spectra, and ideal incubation conditions for bacteriocin production. Based on the obtained results, 21 isolates presented at least one of the three lantibiotics biosynthesis genes (lanB, lanC or lamM), and 23 isolates also produced antimicrobial substances with sensitivity to at least one proteinase, indicating their bacteriocinogenic activity. In general, the isolates had broad inhibitory activity, mainly against Listeria spp. and Staphylococcus spp. strains, and the best antimicrobial performance of the isolates occurred when they were cultivated at 25 °C for 24 or 48 h or at 35 °C for 12 h. The present study identified the bacteriocinogenic potential of Lactobacillus isolates obtained from raw milk and cheese, suggesting their potential use as biopreservatives in foods.

  8. Inhibitory activity of Lactobacillus plantarum TF711 against Clostridium sporogenes when used as adjunct culture in cheese manufacture.

    Science.gov (United States)

    González, Lorena; Zárate, Victoria

    2015-05-01

    Bacteriocins produced by lactic acid bacteria are of great interest to the food-processing industry as natural preservatives. This work aimed to investigate the efficacy of bacteriocin-producing Lactobacillus plantarum TF711, isolated from artisanal Tenerife cheese, in controlling Clostridium sporogenes during cheese ripening. Cheeses were made from pasteurised milk artificially contaminated with 10(4) spores m/l C. sporogenes. Experimental cheeses were manufactured with Lb. plantarum TF711 added at 1% as adjunct to commercial starter culture. Cheeses made under the same conditions but without Lb. plantarum TF711 served as controls. Evolution of microbiological parameters, pH and NaCl content, as well as bacteriocin production was studied throughout 45 d of ripening. Addition of Lb. plantarum TF711 did not bring about any significant change in starter culture counts, NaCl content and pH, compared with control cheese. In contrast, clostridial spore count in experimental cheeses were significantly lower than in control cheeses from 7 d onwards, reaching a maximum reduction of 2·2 log units on day 21. Inhibition of clostridia found in experimental cheeses was mainly attributed to plantaricin activity, which in fact was recovered from these cheeses.

  9. Food preservative potential of gassericin A-containing concentrate prepared from a cheese whey culture supernatant from Lactobacillus gasseri LA39.

    Science.gov (United States)

    Nakamura, Kiyoshi; Arakawa, Kensuke; Kawai, Yasushi; Yasuta, Narimi; Chujo, Takahiro; Watanabe, Masamichi; Iioka, Hiroyuki; Tanioka, Masashi; Nishimura, Junko; Kitazawa, Haruki; Tsurumi, Koichi; Saito, Tadao

    2013-02-01

    Gassericin A (GA) is a circular bacteriocin produced by Lactobacillus gasseri LA39. In this study, GA-containing concentrate was prepared using a cross-flow membrane filtration device (30 kDa cut-off) from the culture supernatant of Lb. gasseri LA39 cultivated in a cheese whey-based food-grade medium. The bacteriocin activity titer in the concentrate was 16 times as high as that of the culture supernatant and was completely maintained through each incubation at 4°C for 3 months, 37°C for 2 months, 60°C for 5 h, and 100°C for 30 min. The GA-containing concentrate was used with glycine powder to make custard creams, and then four representative strains of custard cream spoilage bacteria (Bacillus cereus, Lactococcus lactis subsp. lactis, Achromobacter denitrificans and Pseudomonas fluorescens) were individually inoculated at c. 10(3) colony forming units/g in the custard creams. Throughout 30 days of incubation at 30°C, all of the inoculated bacteria were completely inhibited by the combination of 5% (w/w) of the GA-containing concentrate and 0.5% (w/w) glycine. This is the first highly practical application of GA to foods as a biopreservative, and the concentration method and the bacteriocin concentrate would contribute to biopreservation of several foods. © 2012 The Authors. Animal Science Journal © 2012 Japanese Society of Animal Science.

  10. Evaluation of Antimicrobial Activity of Probiotic Lactobacillus Strains against Growth and Urease Activity of Proteus spp.

    Directory of Open Access Journals (Sweden)

    Leila Goudarzi

    2017-10-01

    Full Text Available Background:    Nowadays, the use of probiotic bacteria for the prevention and treatment of urinary tract infections is growing. Lactobacillus, as probiotic bacterial genus, is well known for its benefits for the human health.Methods:      The effects of partially purified antimicrobial compounds (bacteriocins and biosurfactants of Lactobacillus strains was assessed and their capacity to in vitro inhibit growth and urease production of various strains of Proteus spp, was studied. Inhibition of the urease production of Proteus spp. at sub-MIC levels was screened using spectrophotometry method.  Results:   Results revealed that semi-purified bacteriocins of L. acidophilus and L. plantarum showed a greater inhibitory activity on the bacterial urease, compared to biosurfactants of L. rhamnosus, L. casei and L. fermentum (P < 0.05.Conclusion:    It can be concluded that bacteriocins may affect Proteus pathogenesis by inhibition of the bacterial urease activity and therefore eliminate the stone formation by these bacteria.

  11. A designated centre for people with disabilities operated by St Paul's Child and Family Care Centre Limited, Dublin 9

    LENUS (Irish Health Repository)

    2011-08-30

    Abstract Lactobacillus plantarum LMG P-26358 isolated from a soft French artisanal cheese produces a potent class IIa bacteriocin with 100% homology to plantaricin 423 and bacteriocidal activity against Listeria innocua and Listeria monocytogenes. The bacteriocin was found to be highly stable at temperatures as high as 100°C and pH ranges from 1-10. While this relatively narrow spectrum bacteriocin also exhibited antimicrobial activity against species of enterococci, it did not inhibit dairy starters including lactococci and lactobacilli when tested by well diffusion assay (WDA). In order to test the suitability of Lb. plantarum LMG P-26358 as an anti-listerial adjunct with nisin-producing lactococci, laboratory-scale cheeses were manufactured. Results indicated that combining Lb. plantarum LMG P-26358 (at 108 colony forming units (cfu)\\/ml) with a nisin producer is an effective strategy to eliminate the biological indicator strain, L. innocua. Moreover, industrial-scale cheeses also demonstrated that Lb. plantarum LMG P-26358 was much more effective than the nisin producer alone for protection against the indicator. MALDI-TOF mass spectrometry confirmed the presence of plantaricin 423 and nisin in the appropriate cheeses over an 18 week ripening period. A spray-dried fermentate of Lb. plantarum LMG P-26358 also demonstrated potent anti-listerial activity in vitro using L. innocua. Overall, the results suggest that Lb. plantarum LMG P-26358 is a suitable adjunct for use with nisin-producing cultures to improve the safety and quality of dairy products.

  12. Extracellular secretion of Carocin S1 in Pectobacterium carotovorum subsp. carotovorum occurs via the type III secretion system integral to the bacterial flagellum.

    Science.gov (United States)

    Chan, Yung-Chieh; Wu, Huang-Pin; Chuang, Duen-Yau

    2009-08-27

    Pectobacterium carotovorum subsp. carotovorum is a phytopathogenic enterobacterium responsible for soft rot, a disease characterized by extensive maceration of the affected plant tissue. This species also produces two or more antibacterial substances called bacteriocins, which enhance its competitiveness against related rival species. However, the secretion mechanism for low-molecular-weight bacteriocin is still unknown. A mutant (flhC::Tn5) that did not secrete the low-molecular-weight bacteriocin (LMWB), Carocin S1, was generated by Tn5 insertional mutagenesis. Sequence analysis indicated that this insertion disrupted open reading frame 2 (ORF2) and ORF3 of this strain. Deletion and rescue experiments indicated that ORF2 and ORF3 were both required for extracellular LMWB secretion. The ORF2 and ORF3 sequences showed high homology with the flhD and flhC gene sequences of Pectobacterium carotovorum subsp. atroseptica, Serratia marcescens, Yersinia enterocolitica, and Escherichia coli, indicating that they likely encoded key regulatory components of the type III flagella secretion system. Thus, the extracellular export of Carocin S1 by Pectobacterium carotovorum subsp. carotovorum appears to utilize the type III secretion system integral to bacterial flagella.

  13. OmpF of Pectobacterium carotovorum subsp. carotovorum Pcc3 is required for carocin D sensitivity.

    Science.gov (United States)

    Lim, Jeong-A; Hong, Jisoo; Kim, Jonguk; Heu, Sunggi; Roh, Eunjung

    2016-12-01

    Carocin D is a bacteriocin produced by Pectobacterium carotovorum subsp. carotovorum Pcc21. Carocin D inhibits the growth of P carotovorum subsp. carotovorum and closely related strains. Pectobacterium carotovorum subsp. carotovorum is a causative bacterium for soft rot disease and leads to severe economic losses. Bacteriocins recognize and interact with a specific membrane protein of target bacteria as a receptor. To identify the receptor responsible for carocin D recognition, mutants that underwent a phenotypic change from carocin D sensitivity to carocin D insensitivity were screened. Based on Tn5 insertions, carocin D sensitivity was dependent on expression of the outer membrane protein OmpF. The insensitivity of the mutant (Pcc3MR) to carocin D was complemented with ompF from carocin D-sensitive strains, not from carocin D-resistant strains. The selectivity between sensitive and resistant strains could be attributed to variation in OmpFs in the cell-surface-exposed regions. Based on sequence analysis and complementation assays, it appears that carocin D uses OmpF as a receptor and is translocated by the TonB system. According to previously reported translocation mechanisms of colicins, OmpF works along with the TolA system rather than the TonB system. Therefore, the current findings suggest that carocin D is imported by a unique colicin-like bacteriocin translocation system. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. Extracellular secretion of Carocin S1 in Pectobacterium carotovorum subsp. carotovorum occurs via the type III secretion system integral to the bacterial flagellum

    Directory of Open Access Journals (Sweden)

    Chuang Duen-yau

    2009-08-01

    Full Text Available Abstract Background Pectobacterium carotovorum subsp. carotovorum is a phytopathogenic enterobacterium responsible for soft rot, a disease characterized by extensive maceration of the affected plant tissue. This species also produces two or more antibacterial substances called bacteriocins, which enhance its competitiveness against related rival species. However, the secretion mechanism for low-molecular-weight bacteriocin is still unknown. Results A mutant (flhC::Tn5 that did not secrete the low-molecular-weight bacteriocin (LMWB, Carocin S1, was generated by Tn5 insertional mutagenesis. Sequence analysis indicated that this insertion disrupted open reading frame 2 (ORF2 and ORF3 of this strain. Deletion and rescue experiments indicated that ORF2 and ORF3 were both required for extracellular LMWB secretion. The ORF2 and ORF3 sequences showed high homology with the flhD and flhC gene sequences of Pectobacterium carotovorum subsp. atroseptica, Serratia marcescens, Yersinia enterocolitica, and Escherichia coli, indicating that they likely encoded key regulatory components of the type III flagella secretion system. Conclusion Thus, the extracellular export of Carocin S1 by Pectobacterium carotovorum subsp. carotovorum appears to utilize the type III secretion system integral to bacterial flagella.

  15. Effects of Propionibacterium on the growth and mycotoxin production by some species of Fusarium and Alternaria.

    Science.gov (United States)

    Gwiazdowska, Daniela; Czaczyk, Katarzyna; Filipiak, Marian; Gwiazdowski, Romuald

    2008-01-01

    The aim of this research was to study the antifungal properties of propionibacteria. Three fractions from cultures of Propionibacterium freudenreichii ssp. shermanii 41 and ssp. freudenreichii 111 (i.e. culture containing viable bacteria, cell-free supernatant and bacteriocin preparation) were tested for their ability to inhibit the growth and mycotoxin production of Alternaria alternata, Fusarium culmorum, Fusarium graminearum and Fusarium verticillioides. The growth of the fungi was monitored during cultivation using a plating method. The concentration of toxins produced was measured by HPLC on the 14th day of culture. Altenuene and tenuazonic acid were determined in cultures of A. alternata whilst concentration of nivalenol, deoxynivalenol, fumonisin B1 and zearalenone was measured in Fusarium cultures. The strongest inhibition of growth and toxin production was observed in the presence of cultures containing viable cells and supernatants obtained from propionibacteria cultures. The bacteriocin extracts generally had a weak fungistatic effect on the growth of A. alternata, F. culmorum and F. graminearum. Despite the fact that growth was slower in the presence of bacteriocin extracts than in control trials, none of the preparations prepared from the propionibacteria significantly reduced the level of mycotoxin production. The ability of P. freudenreichii ssp. freudenreichii 111 to remove zearalenone from liquid medium was also evaluated. It was shown that both viable and non-viable cells caused a decrease in zearalenone concentration in the medium.

  16. Development of a Chemically Defined Medium for Better Yield and Purification of Enterocin Y31 from Enterococcus faecium Y31

    Directory of Open Access Journals (Sweden)

    Wenli Liu

    2017-01-01

    Full Text Available The macro- and micronutrients in traditional medium, such as MRS, used for cultivating lactic acid bacteria, especially for bacteriocin production, have not been defined, preventing the quantitative monitoring of metabolic flux during bacteriocin biosynthesis. To enhance Enterocin Y31 production and simplify steps of separation and purification, we developed a simplified chemically defined medium (SDM for the growth of Enterococcus faecium Y31 and production of its bacteriocin, Enterocin Y31. We found that the bacterial growth was unrelated to Enterocin Y31 production in MRS; therefore, both the growth rate and the Enterocin Y31 production were set as the index for investigation. Single omission experiments revealed that 5 g/L NaCl, five vitamins, two nucleic acid bases, MgSO4·7H2O, MnSO4·4H2O, KH2PO4, K2HPO4, CH3COONa, fourteen amino acids, and glucose were essential for the strain’s growth and Enterocin Y31 production. Thus, a novel simplified and defined medium (SDM was formulated with 30 components in total. Consequently, Enterocin Y31 production yield was higher in SDM as compared to either MRS or CDM. SDM improved the Enterocin Y31 production and simplified the steps of purification (only two steps, which has broad potential applications.

  17. Application of bacteriocinogenic Enterococcus mundtii CRL35 and Enterococcus faecium ST88Ch in the control of Listeria monocytogenes in fresh Minas cheese.

    Science.gov (United States)

    Vera Pingitore, Esteban; Todorov, Svetoslav Dimitrov; Sesma, Fernando; Franco, Bernadette Dora Gombossy de Melo

    2012-10-01

    Several strains of Enterococcus spp. are capable of producing bacteriocins with antimicrobial activity against important bacterial pathogens in dairy products. In this study, the bacteriocins produced by two Enterococcus strains (Enterococcus mundtii CRL35 and Enterococcus faecium ST88Ch), isolated from cheeses, were characterized and tested for their capability to control growth of Listeria monocytogenes 426 in experimentally contaminated fresh Minas cheese during refrigerated storage. Both strains were active against a variety of pathogenic and non-pathogenic microorganisms and bacteriocin absorption to various L. monocytogenes, Enterococcus faecalis ATCC 19443 and Lactobacillus sakei ATCC 15521 varied according to the strain and the testing conditions (pH, temperature, presence of salts and surfactants). Growth of L. monocytogenes 426 was inhibited in cheeses containing E. mundtii CRL35 up to 12 days at 8 °C, evidencing a bacteriostatic effect. E. faecium ST88Ch was less effective, as the bacteriostatic affect occurred only after 6 days at 8 °C. In cheeses containing nisin (12.5 mg/kg), less than one log reduction was observed. This research underlines the potential application of E. mundtii CRL35 in the control of L. monocytogenes in Minas cheese. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Two-Component Systems Involved in Susceptibility to Nisin A in Streptococcus pyogenes.

    Science.gov (United States)

    Kawada-Matsuo, Miki; Tatsuno, Ichiro; Arii, Kaoru; Zendo, Takeshi; Oogai, Yuichi; Noguchi, Kazuyuki; Hasegawa, Tadao; Sonomoto, Kenji; Komatsuzawa, Hitoshi

    2016-10-01

    Two-component systems (TCSs) are regulatory systems in bacteria that play important roles in sensing and adapting to the environment. In this study, we systematically evaluated the roles of TCSs in the susceptibility of the group A Streptococcus (GAS; Streptococcus pyogenes) SF370 strain to several types of lantibiotics. Using individual TCS deletion mutants, we found that the deletion of srtRK (spy_1081-spy_1082) in SF370 increased the susceptibility to nisin A, which is produced by Lactococcus lactis ATCC 11454, but susceptibility to other types of lantibiotics (nukacin ISK-1, produced by Staphylococcus warneri, and staphylococcin C55, produced by Staphylococcus aureus) was not altered in the TCS mutants tested. The expression of srtFEG (spy_1085 to spy_1087), which is located downstream of srtRK and is homologous to ABC transporters, was increased in response to nisin A. However, srtEFG expression was not induced by nisin A in the srtRK mutant. The inactivation of srtFEG increased the susceptibility to nisin A. These results suggest that SrtRK controls SrtFEG expression to alter the susceptibility to nisin A. Further experiments showed that SrtRK is required for coexistence with L. lactis ATCC 11454, which produces nisin A. Our results elucidate the important roles of S. pyogenes TCSs in the interactions between different bacterial species, including bacteriocin-producing bacteria. In this study, we focused on the association of TCSs with susceptibility to bacteriocins in S. pyogenes SF370, which has no ability to produce bacteriocins, and reported two major new findings. We demonstrated that the SrtRK TCS is related to susceptibility to nisin A by controlling the ABC transporter SrtFEG. We also showed that S. pyogenes SrtRK is important for survival when the bacteria are cocultured with nisin A-producing Lactococcus lactis This report highlights the roles of TCSs in the colocalization of bacteriocin-producing bacteria and non-bacteriocin-producing bacteria. Our

  19. The Natural Antimicrobial Subtilosin A Synergizes with Lauramide Arginine Ethyl Ester (LAE), ε-Poly-L-lysine (Polylysine), Clindamycin Phosphate and Metronidazole, Against the Vaginal Pathogen Gardnerella vaginalis.

    Science.gov (United States)

    Cavera, Veronica L; Volski, Anna; Chikindas, Michael L

    2015-06-01

    Bacterial vaginosis (BV) is a common, recurrent vaginal infection linked to increased chances of preterm delivery, incidence of sexually transmitted infections and fertility problems. BV is caused by a shift of the vaginal ecosystem from predominately Lactobacillus to a multispecies Actinomyces biofilm with the most common representatives identified as Gardnerella vaginalis and Prevotella spp. Current treatments have been associated with increased resistance as well as negative effects on healthy microbiota. The objective of this study was to evaluate the synergistic potential of ten two-antimicrobial combinations against G. vaginalis and four representative lactobacilli. The four tested antimicrobials were lauramide arginine ethyl ester, ε-poly-L-lysine, clindamycin phosphate, metronidazole and the bacteriocin subtilosin A. The use of bacteriocins as either synergist or alternative treatment positions bacteriocins as an excellent alternative to current antibiotics. The microdilution method was used to determine the minimum inhibitory concentration (MIC) of each of the antimicrobials individually, and the checkerboard assay was used to evaluate these MICs in combination. Clindamycin and subtilosin (CS), and metronidazole and subtilosin were synergistic against G. vaginalis in terms of fractional inhibitory concentration index (FICI). All tested combinations were found to have Bliss synergy. The combination of clindamycin and polylysine (CP) was identified as antagonistic against L. acidophilus in terms of both FICI and Bliss synergy. The combination of clindamycin and metronidazole (CM) was antagonistic against L. vaginalis for both FICI and Bliss synergy. The combinations of CP, clindamycin and LAE, CS, and LAE and polylysine were identified as Bliss antagonistic against L. vaginalis but did not indicate FICI antagonism.

  20. Inhibition of Bacillus cereus Strains by Antimicrobial Metabolites from Lactobacillus johnsonii CRL1647 and Enterococcus faecium SM21.

    Science.gov (United States)

    Soria, M Cecilia; Audisio, M Carina

    2014-12-01

    Bacillus cereus is an endospore-forming, Gram-positive bacterium able to cause foodborne diseases. Lactic acid bacteria (LAB) are known for their ability to synthesize organic acids and bacteriocins, but the potential of these compounds against B. cereus has been scarcely documented in food models. The present study has examined the effect of the metabolites produced by Lactobacillus johnsonii CRL1647 and Enterococcus faecium SM21 on the viability of select B. cereus strains. Furthermore, the effect of E. faecium SM21 metabolites against B. cereus strains has also been investigated on a rice food model. L. johnsonii CRL1647 produced 128 mmol/L of lactic acid, 38 mmol/L of acetic acid and 0.3 mmol/L of phenyl-lactic acid. These organic acids reduced the number of vegetative cells and spores of the B. cereus strains tested. However, the antagonistic effect disappeared at pH 6.5. On the other hand, E. faecium SM21 produced only lactic and acetic acid (24.5 and 12.2 mmol/L, respectively) and was able to inhibit both vegetative cells and spores of the B. cereus strains, at a final fermentation pH of 5.0 and at pH 6.5. This would indicate the action of other metabolites, different from organic acids, present in the cell-free supernatant. On cooked rice grains, the E. faecium SM21 bacteriocin(s) were tested against two B. cereus strains. Both of them were significantly affected within the first 4 h of contact; whereas B. cereus BAC1 cells recovered after 24 h, the effect on B. cereus 1 remained up to the end of the assay. The LAB studied may thus be considered to define future strategies for biological control of B. cereus.

  1. PRODUCTION OF PLANTARCIN BY LACTOBACILLUS PLANTARUM SR18

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    Wagih El-Shouny

    2012-06-01

    Full Text Available Out of 86 lactobacilli previously screened in our laboratory, Lactobacillus plantarum SR18 isolated from yoghurt revealed the largest detected inhibition zone against the selected indicator Streptococcus salivarius 5. The obtained electrophoretic patterns revealed that L. plantarum SR18 was free from plasmids. Exposure of 6 h growing L. plantarum culture to T-8M, 3B ultraviolet B lamp (8w, 220v & 312 nm for 2 h and subsequent growth for further 24 h resulted in an increase of cell-bound bacteriocin titer reached 2 fold at 12 h. Whereas bacteriocin secreted in the culture filtrate was not affected by UV irradiation. Plantarcin SR18 production was maximal (12800 AU/ml between 12 and 18 h by incubation of the culture at 37°C and pH 5-7 in candle jar (CO2. The bacteriocin bound to the cells and that secreted into the culture filtrate of L. plantarum SR18 were precipitated by 75% ammomium sulphate, dialysed and further purified by Gel filtration on Sephadex G-100. The specific activities (AU/mg protein were increased by a factor of about 5.3 and 2.35 for plantarcins purified from proteins bound to the cell of L. plantarum SR18 (plantarcin SR18 a and that secreted into the culture filtrate (plantarcin SR18 b, respectively. Gel filtration of plantarcin SR18a resulted in moderate antibacterial activity (3200 AU/ml and very high activity (25600 AU/ml of plantarcin SR18b.

  2. ISOLASI BAKTERI ASAM LAKTAT DARI KIMCHI DAN KEMAMPUANNYA MENGHASILKAN ZAT ANTI BAKTERI

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    Benedicta Yolanda Khristnaviera

    2017-09-01

    Full Text Available South Korea is famous for its fermented food called Kimchi, a traditional Korean food fermented from pickled vegetables with a mixture of spicy seasoning. Kimchi is now one of functional food products because of there are lactic acid bacteria that are probiotic and can produce bacteriocin compounds. These bacteriocin compounds may inhibit or have anti-bacterial activity. The purpose of this study was to obtain isolates of lactic acid bacteria from store-bought kimchi and homemade kimchi, to examine the antibacterial agent produced by lactic acid bacteria isolated from kimchi against Escherichia coli and Staphylococcus aureus bacteria. We conducted a Disk Diffusion Method to tests the bacteriocin activity, and data were descriptively analyzed. The results showed that eight isolates of lactic acid bacteria from store-bought kimchi and homemade kimchi homemade were able to inhibit the growth of tested bacteria, S. aureus and E. coli. Isolate D1 isolated from store-bought kimchi has largest inhibitory capability against S. aureus and E. coli; it has 16.00 mm and 17.33 mm inhibitory zone, respectively. Isolate B2 isolated from homemade kimchi has the most significant inhibitory ability against S. aureus and E. coli; it has 16.67 mm and 17.67 mm inhibitory zone, respectively. The lowest ability to form clear zone was found on isolate D2 isolated from homemade kimchi. The inhibitory zone of produce by strain D2 against S. aureus and E. coli were 7.67 mm and 8.67 mm, respectively.

  3. Inhibitory activity of Lactobacillus plantarum LMG P-26358 against Listeria innocua when used as an adjunct starter in the manufacture of cheese

    Science.gov (United States)

    2011-01-01

    Lactobacillus plantarum LMG P-26358 isolated from a soft French artisanal cheese produces a potent class IIa bacteriocin with 100% homology to plantaricin 423 and bacteriocidal activity against Listeria innocua and Listeria monocytogenes. The bacteriocin was found to be highly stable at temperatures as high as 100°C and pH ranges from 1-10. While this relatively narrow spectrum bacteriocin also exhibited antimicrobial activity against species of enterococci, it did not inhibit dairy starters including lactococci and lactobacilli when tested by well diffusion assay (WDA). In order to test the suitability of Lb. plantarum LMG P-26358 as an anti-listerial adjunct with nisin-producing lactococci, laboratory-scale cheeses were manufactured. Results indicated that combining Lb. plantarum LMG P-26358 (at 108 colony forming units (cfu)/ml) with a nisin producer is an effective strategy to eliminate the biological indicator strain, L. innocua. Moreover, industrial-scale cheeses also demonstrated that Lb. plantarum LMG P-26358 was much more effective than the nisin producer alone for protection against the indicator. MALDI-TOF mass spectrometry confirmed the presence of plantaricin 423 and nisin in the appropriate cheeses over an 18 week ripening period. A spray-dried fermentate of Lb. plantarum LMG P-26358 also demonstrated potent anti-listerial activity in vitro using L. innocua. Overall, the results suggest that Lb. plantarum LMG P-26358 is a suitable adjunct for use with nisin-producing cultures to improve the safety and quality of dairy products. PMID:21995443

  4. Virulence factors and antibiotic susceptibility in enterococci isolated from oral mucosal and deep infections

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    Gunnar Dahlén

    2012-02-01

    Full Text Available This study evaluates the presence of virulence factors and antibiotic susceptibility among enterococcal isolates from oral mucosal and deep infections. Forty-three enterococcal strains from oral mucosal lesions and 18 from deep infections were isolated from 830 samples that were sent during 2 years to Oral Microbiology, University of Gothenburg, for analysis. The 61 strains were identified by 16S rDNA, and characterized by the presence of the virulence genes efa A (endocarditis gene, gel E (gelatinase gene, ace (collagen binding antigen gene, asa (aggregation substance gene, cyl A (cytolysin activator gene and esp (surface adhesin gene, tested for the production of bacteriocins and presence of plasmids. MIC determination was performed using the E-test method against the most commonly used antibiotics in dentistry, for example, penicillin V, amoxicillin and clindamycin. Vancomycin was included in order to detect vancomycin-resistant enterococci (VRE strains. Sixty strains were identified as Enterococcus faecalis and one as Enterococcus faecium. All the virulence genes were detected in more than 93.3% (efa A and esp of the E. faecalis strains, while the presence of phenotypic characteristics was much lower (gelatinase 10% and hemolysin 16.7%. Forty-six strains produced bacteriocins and one to six plasmids were detected in half of the isolates. Enterococcal strains from oral infections had a high virulence capacity, showed bacteriocin production and had numerous plasmids. They were generally susceptible to ampicillins but were resistant to clindamycin, commonly used in dentistry, and no VRE-strain was found.

  5. Listeriaphages and coagulin C23 act synergistically to kill Listeria monocytogenes in milk under refrigeration conditions.

    Science.gov (United States)

    Rodríguez-Rubio, Lorena; García, Pilar; Rodríguez, Ana; Billington, Craig; Hudson, J Andrew; Martínez, Beatriz

    2015-07-16

    Bacteriophages and bacteriocins are promising biocontrol tools in food. In this work, two Listeria bacteriophages, FWLLm1 and FWLLm3, were assessed in combination with the bacteriocin coagulin C23 to inhibit Listeria monocytogenes. Preliminary results under laboratory conditions demonstrated that both antimicrobials act synergistically when they were applied in suboptimal concentrations. The combined approach was further assessed in milk contaminated with 5×10(4) CFU/ml L. monocytogenes 2000/47 and stored at 4 °C for 10 days. When used alone, phage FWLLm1 added at 5×10(6) PFU/ml, FWLLm3 at 5×10(5) PFU/ml and coagulin C23 at 584 AU/ml kept L. monocytogenes 2000/47 counts lower than the untreated control throughout storage. However, when used in combination, inhibition was enhanced and in the presence of FWLLm1 and coagulin C23, L. monocytogenes 2000/47 counts were under the detection limits (less than 10 CFU/ml) from day 4 until the end of the experiment. Resistant mutants towards phages and coagulin C23 could be obtained, but cross-resistance was not detected. Mutants resistant to FWLLm3 and coagulin C23 were also recovered from surviving colonies after cold storage in milk which may explain the failure of this combination to inhibit L. monocytogenes. Remarkably, the fraction of resistant mutants isolated from the combined treatment was lower than that from each antimicrobial alone, suggesting that synergy between bacteriocins and phages could be due to a lower rate of resistance development and the absence of cross-resistance. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Detection of the pediocin gene pedA in strains from human faeces by real-time PCR and characterization of Pediococcus acidilactici UVA1

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    Cereghetti Tania

    2007-09-01

    Full Text Available Abstract Background Bacteriocin-producing lactic acid bacteria are commonly used as natural protective cultures. Among them, strains of the genus Pediococcus are particularly interesting for their ability to produce pediocin, a broad spectrum antimicrobial peptide with a strong antagonistic activity against the food-borne pathogen Listeria monocytogenes. Furthermore, there is increasing interest in isolating new bacteriocin-producing strains of human intestinal origin that could be developed for probiotic effects and inhibition of pathogenic bacteria in the gut. In this work, we typed a new strain, co-isolated from baby faeces together with a Bifidobacterium thermophilum strain, and characterized its proteinaceous compound with strong antilisterial activity. Results The newly isolated strain UVA1 was identified as a Pediococcus acidilactici by carbohydrate fermentation profile, growth at 50°C and 16S rDNA sequencing. The partially purified bacteriocin was heat resistant up to 100°C, active over a wide range of pH (2 to 9 and susceptible to proteolytic enzymes. The molecular weight, estimated by SDS-PAGE, was similar to that of pediocin AcH/PA-1 (4.5 kDa. P. acidilactici UVA1 harboured a 9.5-kb plasmid that could be cured easily, which resulted in the loss of the antimicrobial activity. Southern hybridization using the DIG-labelled pedA-probe established that the bacteriocin gene was plasmid-borne as for all pediocin described so far. Nucleotide sequence of the whole operon (3.5 kb showed almost 100 % similarity to the pediocin AcH/PA-1 operon. The mRNA transcript for pedA could be detected in P. acidilactici UVA1 but not in the cured derivative, confirming the expression of the pedA-gene in UVA1. Using a new real-time PCR assay, eleven out of seventeen human faecal samples tested were found to contain pedA-DNA. Conclusion We identified and characterised the first pediocin produced by a human intestinal Pediococcus acidilactici isolate and

  7. Inhibition of Bacillus cereus and Bacillus weihenstephanensis in raw vegetables by application of washing solutions containing enterocin AS-48 alone and in combination with other antimicrobials.

    Science.gov (United States)

    Cobo Molinos, Antonio; Abriouel, Hikmate; Lucas López, Rosario; Ben Omar, Nabil; Valdivia, Eva; Gálvez, Antonio

    2008-09-01

    Enterocin AS-48 is a broad-spectrum cyclic antimicrobial peptide produced by Enterococcus faecalis. In the present study, the bacteriocin was tested alone and in combination with other antimicrobials for decontamination of Bacillus inoculated on alfalfa, soybean sprouts and green asparagus. Washing with enterocin AS-48 solutions reduced viable cell counts of Bacillus cereus and Bacillus weihenstephanensis by 1.0-1.5 and by 1.5-2.38 log units right after application of treatment, respectively. In both cases, the bacteriocin was effective in reducing the remaining viable population below detection levels during further storage of the samples at 6 degrees C, but failed to prevent regrowth in samples stored at 15 or 22 degrees C. Application of washing treatments containing enterocin AS-48 in combination with several other antimicrobials and sanitizers (cinnamic and hydrocinnamic acids, carvacrol, polyphosphoric acid, peracetic acid, hexadecylpyridinium chloride and sodium hypochlorite) greatly enhanced the bactericidal effects. The combinations of AS-48 and sodium hypochlorite, peracetic acid or hexadecylpyridinium chloride provided the best results. After application of the combined treatments on alfalfa sprouts contaminated with B. cereus or with B. weihenstephanensis, viable bacilli were not detected or remained at very low concentrations in the treated samples during a 1-week storage period at 15 degrees C. Inhibition of B. cereus by in situ produced bacteriocin was tested by cocultivation with the AS-48 producer strain E. faecalis A-48-32 inoculated on soybean sprouts. Strain A-48-32 was able to grow and produce bacteriocin on sprouts both at 15 and 22 degrees C. At 15 degrees C, growth of B. cereus was completely inhibited in the cocultures, while a much more limited effect was observed at 22 degrees C. The results obtained for washing treatments are very encouraging for the application of enterocin AS-48 in the decontamination of sprouts. Application of washing

  8. Molecular cloning and characterization of an Erwinia carotovora subsp. carotovora pectin lyase gene that responds to DNA-damaging agents.

    OpenAIRE

    McEvoy, J L; Murata, H; Chatterjee, A K

    1990-01-01

    recA-mediated production of pectin lyase (PNL) and the bacteriocin carotovoricin occurs in Erwinia carotovora subsp. carotovora 71 when this organism is subjected to agents that damage or inhibit the synthesis of DNA. The structural gene pnlA was isolated from a strain 71 cosmid gene library following mobilization of the cosmids into a moderate PNL producer, strain 193. The cosmid complemented pnl::Tn5 but not ctv::Tn5 mutations. A constitutive level of PNL activity was detected in RecA+ and ...

  9. In vitro study of beneficial properties and safety of lactic acid bacteria isolated from Portuguese fermented meat products.

    Science.gov (United States)

    Todorov, S D; Franco, B D G M; Wiid, I J

    2014-09-01

    Many lactic acid bacteria produce bacteriocins with a rather broad spectrum of inhibition, which could offer potential applications in food preservation. Bacteriocin production by starter cultures may bring advantage to these strains in competitive interactions with pathogenic bacteria from the food matrix. The objective of this study was to determine the safety of beneficial strains (Lactobacillus plantarum ST202Ch and ST216Ch, Enterococcus faecium ST211Ch, and Lactobacillus sakei ST22Ch, ST153Ch and ST154Ch) previously isolated from fermented meat products and characterised as bacteriocin producers. Auto-aggregation was strain-specific, and values of 28.97, 27.86 and 28.56% were recorded for L. sakei ST22Ch, ST153Ch and ST154Ch, respectively, 16.95 and 14.58% for L. plantarum ST202Ch and ST216Ch, respectively, and 12.77% for E. faecium ST211Ch. Various degrees of co-aggregation between 28.85 and 44.76% for Listeria monocytogenes 211 and 409, and between 23.60 to 34.96% for E. faecium ATCC 19443 were observed. According to the results of the diffusion method, the studied strains demonstrated susceptibility to penicillin G, ampicillin, amoxicillin, amoxicillin/clavulonic acid, imipenem, linezolid, and tetracycline. In addition, the susceptibility of the six strains to various non-antibiotic commercial drugs was examined. Production of β-galactosidase by L. sakei ST22Ch, ST153Ch and ST154Ch, L. plantarum ST202Ch and ST216Ch, and E. faecium ST211Ch was confirmed by employing sterile filter paper discs impregnated with o-nitrophenyl-β-D-galactopyranose. A statistically significant (P<0.001) inhibition of Mycobacterium tuberculosis growth by bacteriocins produced by L. plantarum ST202Ch (38.3%) and ST216Ch (48.6%), L. sakei ST153Ch (16.2%) and ST154Ch (16.1%), and E. faecium ST211Ch (21.7%) was observed. As determined by the polymerase chain reaction, the tested strains showed a low virulence gene profile.

  10. Antibacterial Activity of Stenotrophomonas maltophilia Endolysin P28 against both Gram-positive and Gram-negative Bacteria

    OpenAIRE

    Dong, Hongling; Zhu, Chaoyang; Chen, Jingyi; Ye, Xing; Huang, Yu-Ping

    2015-01-01

    Maltocin P28 is a phage-tail like bacteriocin produced by Stenotrophomonas maltophilia P28. The ORF8 of maltocin P28 gene cluster is predicted to encode an endolysin and we name it endolysin P28. Sequence analysis revealed that it contains the lysozyme_like superfamily conserved domain. Endolysin P28 has the four consensus motifs as that of Escherichia coli phage lambda gpR. In this study, endolysin P28 was expressed in E. coli BL21 (DE3) and purified with a C-terminal oligo-histidine tag. Th...

  11. Antibacterial activity of Stenotrophomonas maltophilia endolysin P28 against both Gram-positive and Gram-negative bacteria

    OpenAIRE

    Hongling eDong; Chaoyang eZhu; Jingyi eChen; Xing eYe; Yu-Ping eHuang; Yu-Ping eHuang

    2015-01-01

    Maltocin P28 is a phage-tail like bacteriocin produced by Stenotrophomonas maltophilia P28. The ORF8 of maltocin P28 gene cluster is predicted to encode an endolysin and we name it endolysin P28. Sequence analysis revealed that it contains the lysozyme_like superfamily conserved domain. Endolysin P28 has the four consensus motifs as that of Escherichia coli phage lambda gpR. In this study endolysin P28 was expressed in E. coli BL21 (DE3) and purified with a C-terminal oligo-histidine tag. The...

  12. EFFECTIVE FACTORS AND MODEL SYSTEMS IN THE INDUSTRIAL PRODUCTION OF NISIN

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    Ömer ŞİMŞEK

    2007-01-01

    Full Text Available Nisin is the first bacteriocin identified in Lactococcus lactis and belongs to type 1 lanthibiotic group. High nisin production in cultured media is related with the composition of fermentation medium, pH, produced nisin concentration and most importantly growth amount of cell. For industrial purpose, batch, fed-batch and continue fermentation systems were developed by regarding these factors. Maintaining efficient production of nisin having important potential at preservation of foods is important for both industrial production and using as starter culture. In this review the fermentation factors at nisin production were outlined and constructed model systems were compared.

  13. Antimicrobial activity of lactic acid bacteria and the spectrum of their biopeptides against spoiling germs in foods

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    Fatima Djadouni

    2012-06-01

    Full Text Available The objective of this study was to isolate LAB from dairy, meat products and agro-industrial wastes and to investigate their antagonist activity. A total of 141 isolates were screened for the inhibitory effect on ten indicator strains in the agar spot test. Results showed that strain LBbb0141 contained antimicrobial compound with wide spectrum that inhibited the growth of ten indicator Gram-positive and Gram-negative strains. The bacteriocin activity attained its maximum value using the MRS agar at initial pH 7.5 and 30°C incubation temperature.

  14. Bacteriocinogenic potential and safety evaluation of non-starter Enterococcus faecium strains isolated from home made white brine cheese.

    Science.gov (United States)

    Favaro, Lorenzo; Basaglia, Marina; Casella, Sergio; Hue, Isabelle; Dousset, Xavier; Gombossy de Melo Franco, Bernadette Dora; Todorov, Svetoslav Dimitrov

    2014-04-01

    Four LAB strains, isolated from Bulgarian home made white brine cheese, were selected for their effective inhibition against Listeria monocytogenes. According to their biochemical and physiological characteristics, the strains were classified as members of Enterococcus genus, and then identified as Enterococcus faecium by 16S rDNA sequencing. Their bacteriocin production and inhibitory spectrum were evaluated together with the occurrence of several bacteriocin genes (entA, entB, entP, entL50B). Their virulence potential and safety was assessed both using PCR targeted to the genes gelE, hyl, asa1, esp, cylA, efaA, ace, vanA, vanB, hdc1, hdc2, tdc and odc and by phenotypical tests for antibiotic resistance, gelatinase, lipase, DNAse and α- and β-haemolysis. The E. faecium strains harboured at least one enterocin gene while the occurrence of virulence, antibiotic resistance and biogenic amines genes was limited. Considering their strong antimicrobial activity against L. monocytogenes strains, the four E. faecium strains exhibited promising potential as bio-preservatives cultures for fermented food productions. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Plant-expressed pyocins for control of Pseudomonas aeruginosa.

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    Šarūnas Paškevičius

    Full Text Available The emergence, persistence and spread of antibiotic-resistant human pathogenic bacteria heralds a growing global health crisis. Drug-resistant strains of gram-negative bacteria, such as Pseudomonas aeruginosa, are especially dangerous and the medical and economic burden they impose underscore the critical need for finding new antimicrobials. Recent studies have demonstrated that plant-expressed bacteriocins of the colicins family can be efficient antibacterials against all major enteropathogenic strains of E. coli. We extended our studies of colicin-like bacteriocins to pyocins, which are produced by strains of P. aeruginosa for ecological advantage against other strains of the same species. Using a plant-based transient expression system, we expressed six different pyocins, namely S5, PaeM, L1, L2, L3 and one new pyocin, PaeM4, and purified them to homogeneity. Among these pyocins, PaeM4 demonstrated the broadest spectrum of activity by controlling 53 of 100 tested clinical isolates of P. aeruginosa. The activity of plant-made pyocins was confirmed in the agar drop, liquid culture susceptibility and biofilm assays, and in the Galleria mellonella animal infection model.

  16. In situ control of food spoilage fungus using Lactobacillus acidophilus NCDC 291.

    Science.gov (United States)

    Garcha, Seema; Natt, Navdeep Kaur

    2012-10-01

    A challenge for food industry today is to produce minimally processed food, without use of chemical preservatives and little compromise on nutritional status. Lactobacillus acidophilus NCDC 291 can be directly added to food where it enhances shelf life by competing with other microflora (both bacterial and fungal) for food and also by production of antimicrobial metabolites as bacteriocins. Comprehensive studies have demonstrated the in vitro activity of bacteriocins. However their role in preventing fresh food spoilage needs more elucidation. The present study was conducted to evaluate the efficacy of the whole cells of this organism as biopreservative agent against fungi. Four most commonly occurring spoilage fungi were isolated and were identified as Fusarium, Alternaria, Penicillium and Aspergillus. Growth of all of them was inhibited in in vitro studies, (approximately 33-43% decrease in mycelial dry weight basis between test and control). In situ biopreservation of Indian cheese and raw poultry meat was attempted and the colony count of Alternaria was significantly (p spoilage was not observed up to 6 days.

  17. Characterization of starter kimchi fermented with Leuconostoc kimchii GJ2 and its cholesterol-lowering effects in rats fed a high-fat and high-cholesterol diet.

    Science.gov (United States)

    Jo, Se Yeon; Choi, Eun A; Lee, Jae Joon; Chang, Hae Choon

    2015-10-01

    The hypocholesterolemic effects of lactic acid bacteria and kimchi have been demonstrated previously. However, the kimchi fermentation process still relies on naturally present microorganisms. To obtain functional kimchi with consistent quality, we validated the capacity of Leuconostoc kimchii GJ2 as a starter culture to control kimchi fermentation. Moreover, cholesterol-lowering effects of starter kimchi as a health-promoting product were explored. Bacteriocin production by Lc. kimchii GJ2 was highly enhanced in the presence of 5% Lactobacillus sakei NJ1 cell fractions. When kimchi was fermented with bacteriocin-enhanced Lc. kimchii GJ2, Lc. kimchii GJ2 became overwhelmingly predominant (98.3%) at the end of fermentation and maintained its dominance (up to 82%) for 84 days. Growing as well as dead cells of Lc. kimchii GJ2 showed high cholesterol assimilation (in vitro). Rats were fed a high-fat and high-cholesterol diet supplemented with starter kimchi. The results showed that feeding of starter kimchi significantly reduced serum total cholesterol, triglyceride and low-density lipoprotein cholesterol levels. Additionally, atherogenic index, cardiac risk factor and triglyceride and total cholesterol levels in liver and epididymal adipose tissue decreased significantly in rats fed starter kimchi. Kimchi fermented with Lc. kimchii GJ2 as a starter culture has efficient cholesterol-lowering effects. © 2014 Society of Chemical Industry.

  18. Antimicrobial activity of Lactobacillus acidophilus against pathogenic and food spoilage microorganisms: A review

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    T. Dinev

    2017-03-01

    Full Text Available Abstract. The purpose of this review is to summarize the information regarding the antimicrobial activity of Lactobacillus acidophilus, an important species of lactic acid bacteria. Lactic acid bacteria are constituents of many beneficent for the consumer's health food products. They are considered potentially promising in the strategy to combat infections and prevent the growth of spoilage microorganisms, and also have antimutagenic, anticarcinogenic, hypolipidemic and hypocholesterolemic properties, improve the lactose metabolism, stimulate the immune system, etc. In the resent years Lactobacillus acidophilus is considered the main probiotic species in the intestinal tract of healthy humans and is widely used in functional dairy foods. It produces a variety of metabolic products with antimicrobial properties, including organic acids and bacteriocins, such as lactacins B and F, acidophilin, acidocin, acidophilucin, acidophilicin, which are active against many pathogenic and spoilage microorganisms - Escherichia coli (including Escherichi coli 0157:H7, Staphylococcus aureus, Pseudomonas aeruginosa, Listeria monocytogenes, Vibrio parahaemolyticus, Vibrio cholerae, Helicobacter pylori, Klebsiella, Salmonella, Shigella, Bacillus, Clostridium, Mucor, Aspergillus, Fusarium, Trichoderma and Candida spp., etc. Because of the above mentioned reasons Lactobacillus acidophilus could be used as an alternative therapeutic agent against infections caused by susceptible microorganisms. On the other hand Lactobacillus acidophilus based antimicrobial products (mainly bacteriocins and pure cultures could also be applied to food products to prevent the growth of spoilage microorganisms and food-borne pathogens. To better understand the mode of action and the spectrum of antifungal activity more clinical and laboratory studies of different Lactobacillus acidophilus strains are required.

  19. Les entérocoques : avantages et inconvénients en biotechnologie (synthèse bibliographique

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    Aguilar-Galvez, A.

    2012-01-01

    Full Text Available Enterococci: advantages and drawbacks in biotechnology, a review. Enterococci are lactic acid bacteria that have been used for centuries in food processing. These microorganisms play a vital role in conservation (extension of shelf life and in the bacteriological quality of food while keeping their nutritional and organoleptic properties. However, Enterococcus faecium and Enterococcus faecalis are indicators of faecal contamination and are also implicated in nosocomial diseases. The genetic plasticity (transfer of genetic elements of these bacteria allows them not only to adapt to various ecosystems, but also to be vehicles of antibiotic resistances and bacterial virulence, which is of public health concern. Thus, the use of enterococci in the food industry is becoming controversial. However, enterococci are also involved in the fermentation of many foods (milk, vegetables, meats or fish and are able to produce various antimicrobial molecules (e.g. lactic acid, bacteriocins or hydrogen peroxide that make them indispensable in the food industry. Their use as probiotic must therefore be carefully characterized in order to prove their safety. The wide range of bacteriocins (enterocins found in these bacteria could also be valorized by developing purification methods to replace the bacterial strains themselves by their enterocins in foodstuffs, therefore eliminating the risk of direct use of bacteria.

  20. Targeting the microbiota to address diet-induced obesity: a time dependent challenge.

    Directory of Open Access Journals (Sweden)

    Siobhan F Clarke

    Full Text Available Links between the gut microbiota and host metabolism have provided new perspectives on obesity. We previously showed that the link between the microbiota and fat deposition is age- and time-dependent subject to microbial adaptation to diet over time. We also demonstrated reduced weight gain in diet-induced obese (DIO mice through manipulation of the gut microbiota with vancomycin or with the bacteriocin-producing probiotic Lactobacillus salivarius UCC118 (Bac(+, with metabolic improvement achieved in DIO mice in receipt of vancomycin. However, two phases of weight gain were observed with effects most marked early in the intervention phase. Here, we compare the gut microbial populations at the early relative to the late stages of intervention using a high throughput sequencing-based analysis to understand the temporal relationship between the gut microbiota and obesity. This reveals several differences in microbiota composition over the intervening period. Vancomycin dramatically altered the gut microbiota composition, relative to controls, at the early stages of intervention after which time some recovery was evident. It was also revealed that Bac(+ treatment initially resulted in the presence of significantly higher proportions of Peptococcaceae and significantly lower proportions of Rikenellaceae and Porphyromonadaceae relative to the gut microbiota of L. salivarius UCC118 bacteriocin negative (Bac(- administered controls. These differences were no longer evident at the later time. The results highlight the resilience of the gut microbiota and suggest that interventions may need to be monitored and continually adjusted to ensure sustained modification of the gut microbiota.