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Sample records for circular bacteriocin produced

  1. New type non-lantibiotic bacteriocins: circular and leaderless bacteriocins.

    Science.gov (United States)

    Masuda, Y; Zendo, T; Sonomoto, K

    2012-03-01

    Bacteriocins are antimicrobial peptides that are ribosomally synthesised by bacteria. Bacteriocins produced by Gram-positive bacteria, including lactic acid bacteria, are under focus as the next generation of safe natural biopreservatives and as therapeutic alternatives to antibiotics. Recently, two novel types of non-lantibiotic class II bacteriocins have been reported with unique characteristics in their structure and biosynthesis mechanism. One is a circular bacteriocin that contains a head-to-tail structure in the mature form, and the other is a leaderless bacteriocin without an N-terminal extension in the precursor peptide. A circular structure can provide the peptide with remarkable stability against various stresses; indeed, circular bacteriocins are known to possess higher stability than general linear bacteriocins. Leaderless bacteriocins are distinct from general bacteriocins, because they do not contain N-terminal leader sequences, which are responsible for the recognition process during secretion and for inactivation of bacteriocins inside producer cells. Leaderless bacteriocins do not require any post-translational processing for activity. These two novel types of bacteriocins are promising antimicrobial compounds, and their biosynthetic mechanisms are expected to be applied in synthetic biology to design new peptides and for new mass production systems. However, many questions remain about their biosynthesis. In this review, we introduce recent studies on these types of bacteriocins and their potential to open a new world of antimicrobial peptides.

  2. Class IIc or Circular Bacteriocins

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    Martin-Visscher, Leah A.; van Belkum, Marco J.; Vederas, John C.

    The circular bacteriocins produced by Gram-positive bacteria represent a diverse class of antimicrobial peptides. These bacteriocins display enhanced stability compared to linear bacteriocins, which arises from their characteristic circular backbone. Currently, eight unique circular bacteriocins have been identified, and analysis of their gene clusters indicates that they likely utilize complex mechanisms for maturation and secretion, as well as for immunity. These bacteriocins target the cytoplasmic membrane of sensitive cells, leading to pore formation that results in loss of ions, dissipation of membrane potential, and ultimately, cell death. Structural studies suggest that despite variation in their sequences, most of these bacteriocins likely adopt a common three-dimensional architecture, consisting of four or five tightly packed helices encompassing a hydrophobic core. There are many mysteries surrounding the biosynthesis of these peptides, particularly in regard to the mechanism by which they are cyclized. Elucidation of such a mechanism may provide exciting new approaches to the bioengineering of new, stable, and antimicrobially active circular peptides.

  3. Solution structure of acidocin B, a circular bacteriocin produced by Lactobacillus acidophilus M46.

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    Acedo, Jeella Z; van Belkum, Marco J; Lohans, Christopher T; McKay, Ryan T; Miskolzie, Mark; Vederas, John C

    2015-04-01

    Acidocin B, a bacteriocin produced by Lactobacillus acidophilus M46, was originally reported to be a linear peptide composed of 59 amino acid residues. However, its high sequence similarity to gassericin A, a circular bacteriocin from Lactobacillus gasseri LA39, suggested that acidocin B might be circular as well. Acidocin B was purified from culture supernatant by a series of hydrophobic interaction chromatographic steps. Its circular nature was ascertained by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry and tandem mass spectrometry (MS/MS) sequencing. The peptide sequence was found to consist of 58 amino acids with a molecular mass of 5,621.5 Da. The sequence of the acidocin B biosynthetic gene cluster was also determined and showed high nucleotide sequence similarity to that of gassericin A. The nuclear magnetic resonance (NMR) solution structure of acidocin B in sodium dodecyl sulfate micelles was elucidated, revealing that it is composed of four α-helices of similar length that are folded to form a compact, globular bundle with a central pore. This is a three-dimensional structure for a member of subgroup II circular bacteriocins, which are classified based on their isoelectric points of ∼7 or lower. Comparison of acidocin B with carnocyclin A, a subgroup I circular bacteriocin with four α-helices and a pI of 10, revealed differences in the overall folding. The observed variations could be attributed to inherent diversity in their physical properties, which also required the use of different solvent systems for three-dimensional structural elucidation.

  4. Circular bacteriocins: biosynthesis and mode of action.

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    Gabrielsen, Christina; Brede, Dag A; Nes, Ingolf F; Diep, Dzung B

    2014-11-01

    Circular bacteriocins are a group of N-to-C-terminally linked antimicrobial peptides, produced by Gram-positive bacteria of the phylum Firmicutes. Circular bacteriocins generally exhibit broad-spectrum antimicrobial activity, including against common food-borne pathogens, such as Clostridium and Listeria spp. These peptides are further known for their high pH and thermal stability, as well as for resistance to many proteolytic enzymes, properties which make this group of bacteriocins highly promising for potential industrial applications and their biosynthesis of particular interest as a possible model system for the synthesis of highly stable bioactive peptides. In this review, we summarize the current knowledge on this group of bacteriocins, with emphasis on the recent progress in understanding circular bacteriocin genetics, biosynthesis, and mode of action; in addition, we highlight the current challenges and future perspectives for the application of these peptides.

  5. Structure and genetics of circular bacteriocins.

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    van Belkum, Marco J; Martin-Visscher, Leah A; Vederas, John C

    2011-08-01

    Circular bacteriocins are antimicrobial peptides produced by a variety of Gram-positive bacteria. They are part of a growing family of ribosomally synthesized peptides with a head-to-tail cyclization of their backbone that are found in mammals, plants, fungi and bacteria and are exceptionally stable. These bacteriocins permeabilize the membrane of sensitive bacteria, causing loss of ions and dissipation of the membrane potential. Most circular bacteriocins probably adopt a common 3D structure consisting of four or five α-helices encompassing a hydrophobic core. This review compares the various structures, as well as the gene clusters that encode circular bacteriocins, and discusses the biogenesis of this unique class of bacteriocins.

  6. 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

    2008-01-01

    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 mat

  7. 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

    2008-01-01

    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 mat

  8. 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

  9. DNA Sequencing and Homologous Expression of a Small Peptide Conferring Immunity to Gassericin A, a Circular Bacteriocin Produced by Lactobacillus gasseri LA39

    NARCIS (Netherlands)

    Kawai, Yasushi; Kusnadi, Joni; Kemperman, Rober; Kok, Jan; Ito, Yoshiyuki; Endo, Mikiko; Arakawa, Kensuke; Uchida, Hideaki; Nishimura, Junko; Kitazawa, Haruki; Saito, Tadao

    2009-01-01

    Gassericin A, produced by Lactobacillus gasseri LA39, is a hydrophobic circular bacteriocin. The DNA region surrounding the gassericin A structural gene, gaaA, was sequenced, and seven open reading frames (ORFs) of 3.5 kbp (gaaBCADITE) were found with possible functions in gassericin A production, s

  10. Bacteriocin producers from traditional food products

    OpenAIRE

    Thonart P.; Destain J.; Tine E.; Ngom A.; Diop MB.; Dubois-Dauphin R.

    2007-01-01

    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 identifi ed 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 L...

  11. 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.

  12. [Bacteriocins produced by lactic acid bacteria].

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    Bilková, Andrea; Sepova, Hana Kinová; Bilka, Frantisek; Balázová, Andrea

    2011-04-01

    Lactic acid bacteria comprise several genera of gram-positive bacteria that are known for the production of structurally different antimicrobial substances. Among them, bacteriocins are nowadays in the centre of scientific interest. Bacteriocins, proteinaceous antimicrobial substances, are produced ribosomally and have usually a narrow spectrum of bacterial growth inhibition. According to their structure and the target of their activity, they are divided into four classes, although there are some suggestions for a renewed classification. The most interesting and usable class are lantibiotics. They comprise the most widely commercially used and well examined bacteriocin, nisin. The non-pathogenic character of lactic acid bacteria is advantageous for using their bacteriocins in food preservation as well as in feed supplements or in veterinary medicine.

  13. 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 b

  14. 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 b

  15. 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

  16. Resistance to bacteriocins produced by Gram-positive bacteria.

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    Bastos, Maria do Carmo de Freire; Coelho, Marcus Lívio Varella; Santos, Olinda Cabral da Silva

    2015-04-01

    Bacteriocins are prokaryotic proteins or peptides with antimicrobial activity. Most of them exhibit a broad spectrum of activity, inhibiting micro-organisms belonging to different genera and species, including many bacterial pathogens which cause human, animal or plant infections. Therefore, these substances have potential biotechnological applications in either food preservation or prevention and control of bacterial infectious diseases. However, there is concern that continuous exposure of bacteria to bacteriocins may select cells resistant to them, as observed for conventional antimicrobials. Based on the models already investigated, bacteriocin resistance may be either innate or acquired and seems to be a complex phenomenon, arising at different frequencies (generally from 10(-9) to 10(-2)) and by different mechanisms, even amongst strains of the same bacterial species. In the present review, we discuss the prevalence, development and molecular mechanisms involved in resistance to bacteriocins produced by Gram-positive bacteria. These mechanisms generally involve changes in the bacterial cell envelope, which result in (i) reduction or loss of bacteriocin binding or insertion, (ii) bacteriocin sequestering, (iii) bacteriocin efflux pumping (export) and (iv) bacteriocin degradation, amongst others. Strategies that can be used to overcome this resistance are also addressed.

  17. Utilization of bacteriocin-producing bacteria in dairy products

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    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.

  18. Actinomycetemcomitin: a new bacteriocin produced by Aggregatibacter (Actinobacillus) actinomycetemcomitans.

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    Lima, Francisca Lúcia; de Carvalho, Maria Auxiliadora Roque; Apolônio, Ana Carolina Morais; Bemquerer, Marcelo Porto; Santoro, Marcelo Matos; Oliveira, Jamil Silvano; Alviano, Celuta Sales; Farias, Luiz de Macêdo

    2008-02-01

    Aggregatibacter (Actinobacillus) actinomycetemcomitans P(7-20) strain isolated from a periodontally diseased patient has produced a bacteriocin (named as actinomycetemcomitin) that is active against Peptostreptococcus anaerobius ATCC 27337. Actinomycetemcomitin was produced during exponential and stationary growth phases, and its amount decreased until it disappeared during the decline growth phase. It was purified by ammonium sulphate precipitation (30-60% saturation), and further by FPLC (mono-Q ionic exchange and Phenyl Superose hydrophobic interaction) and HPLC (C-18 reversed-phase). This bacteriocin loses its activity after incubation at a pH below 7.0 or above 8.0, following heating for 30 min at 45 degrees C, and after treatment with proteolytic enzymes such as trypsin, alpha-chymotrypsin, and papain. Actinomycetemcomitin has a molecular mass of 20.3 KDa and it represents a new bacteriocin from A. actinomycetemcomitans.

  19. Identification of Lactococcus-Specific Bacteriocins Produced by Lactococcal Isolates, and the Discovery of a Novel Bacteriocin, Lactococcin Z.

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    Ishibashi, Naoki; Seto, Hiromi; Koga, Shoko; Zendo, Takeshi; Sonomoto, Kenji

    2015-09-01

    Lactic acid bacteria that produce Lactococcus-specific bacteriocins were isolated and identified as Lactococcus lactis from fresh corn or lettuce. Among them, four isolates were identified as lactococcin Q producers. Seven isolates showed antimicrobial activity against a lactococcin Q producer, L. lactis QU 4, as well as against nisin Z and lacticin Q producers belonging to L. lactis. Strain QU 7 was selected as a standard strain and showed no cross-immunity to lactococcin Q or other lactococcal bacteriocins. The bacteriocin produced by strain QU 7 was purified in three chromatographic steps, and its molecular mass was determined to be 5041.35 Da. The amino acid sequence analysis revealed that it is a novel class IId bacteriocin, referred to as lactococcin Z. It consisted of 45 amino acid residues. The lczA gene encoding the prepeptide of lactococcin Z showed homology to lactococcins A, B, and M. Thus, this report demonstrates a new example of Lactococcus-specific bacteriocins.

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

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    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.

  1. Bacteriocins produced by lactic acid bacteria: A review

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    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

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

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    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.

  3. Screening and characterization of novel bacteriocins from lactic acid bacteria.

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    Zendo, Takeshi

    2013-01-01

    Bacteriocins produced by lactic acid bacteria (LAB) are expected to be safe antimicrobial agents. While the best studied LAB bacteriocin, nisin A, is widely utilized as a food preservative, various novel ones are required to control undesirable bacteria more effectively. To discover novel bacteriocins at the early step of the screening process, we developed a rapid screening system that evaluates bacteriocins produced by newly isolated LAB based on their antibacterial spectra and molecular masses. By means of this system, various novel bacteriocins were identified, including a nisin variant, nisin Q, a two-peptide bacteriocin, lactococcin Q, a leaderless bacteriocin, lacticin Q, and a circular bacteriocin, lactocyclicin Q. Moreover, some LAB isolates were found to produce multiple bacteriocins. They were characterized as to their structures, mechanisms of action, and biosynthetic mechanisms. Novel LAB bacteriocins and their biosynthetic mechanisms are expected for applications such as food preservation and peptide engineering.

  4. Discovering the bacterial circular proteins : bacteriocins, cyanobactins, and pilins

    NARCIS (Netherlands)

    Montalban-Lopez, Manuel; Sanchez-Hidalgo, Marina; Cebrian, Ruben; Maqueda, Mercedes

    2012-01-01

    Over recent years, several examples of natural ribosomally synthesized circular proteins and peptides from diverse organisms have been described. They are a group of proteins for which the precursors must be post-translationally modified to join the N and C termini with a peptide bond. This feature

  5. Genome sequence of the bacteriocin-producing oral probiotic Streptococcus salivarius strain M18.

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    Heng, Nicholas C K; Haji-Ishak, Nurul S; Kalyan, Alaina; Wong, Andrew Y C; Lovric, Marija; Bridson, Joanna M; Artamonova, Julia; Stanton, Jo-Ann L; Wescombe, Philip A; Burton, Jeremy P; Cullinan, Mary P; Tagg, John R

    2011-11-01

    Streptococcus salivarius is a Gram-positive bacterial commensal and pioneer colonizer of the human oral cavity. Many strains produce ribosomally synthesized proteinaceous antibiotics (bacteriocins), and some strains have been developed for use as oral probiotics. Here, we present the draft genome sequence of the bacteriocin-producing oral probiotic S. salivarius strain M18.

  6. Purification and Characterization of a Bacteriocin Produced by Lactobacillus lactis Isolated from Marine Environment

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    P. Manivasagan

    2010-03-01

    Full Text Available Bacteriocin producing Lactobacillus lactis strain isolated from marine environment, showed broadrange of antibacterial activity against some major food borne pathogens. Maximum bacteriocin production wasobserved at 30°C , pH 6.0 and 1.5% sodium chloride solution. In addition of enzymes, "-amylase, DNase,RNase and lipase were slightly positive effect bacteriocin production. Proteinase K and pepsin were stronglyinhibited bacteriocin production. Among detergents, Sodium dodecyl sulphate (SDS, Tween 80 and TritoneX-100 stimulated bacteriocin production and strongly inhibited by EDTA and urea. The bacteriocin has purifiedby ammonium sulphate precipitate and ion exchange (DEAE cellulose chromatography. Biochemically it waspure protein moiety and the molecular weight was 94 kDa. The study revealed the possibility of usingbacteriocin as a food preservative and the L. lactis strain as probiotic.

  7. 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.

  8. Identification, purification and characterization of laterosporulin, a novel bacteriocin produced by Brevibacillus sp. strain GI-9.

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    Pradip Kumar Singh

    Full Text Available BACKGROUND: Bacteriocins are antimicrobial peptides that are produced by bacteria as a defense mechanism in complex environments. Identification and characterization of novel bacteriocins in novel strains of bacteria is one of the important fields in bacteriology. METHODOLOGY/FINDINGS: The strain GI-9 was identified as Brevibacillus sp. by 16 S rRNA gene sequence analysis. The bacteriocin produced by strain GI-9, namely, laterosporulin was purified from supernatant of the culture grown under optimal conditions using hydrophobic interaction chromatography and reverse-phase HPLC. The bacteriocin was active against a wide range of Gram-positive and Gram-negative bacteria. MALDI-TOF experiments determined the precise molecular mass of the peptide to be of 5.6 kDa and N-terminal sequencing of the thermo-stable peptide revealed low similarity with existing antimicrobial peptides. The putative open reading frame (ORF encoding laterosporulin and its surrounding genomic region was fished out from the draft genome sequence of GI-9. Sequence analysis of the putative bacteriocin gene did not show significant similarity to any reported bacteriocin producing genes in database. CONCLUSIONS: We have identified a bacteriocin producing strain GI-9, belonging to the genus Brevibacillus sp. Biochemical and genomic characterization of laterosporulin suggests it as a novel bacteriocin with broad spectrum antibacterial activity.

  9. Characterisation of an antiviral pediocin-like bacteriocin produced by Enterococcus faecium.

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    Todorov, Svetoslav Dimitrov; Wachsman, Monica; Tomé, Elisabetta; Dousset, Xavier; Destro, Maria Teresa; Dicks, Leon Milner Theodore; Franco, Bernadette Dora Gombossy de Melo; Vaz-Velho, Manuella; Drider, Djamel

    2010-10-01

    The bacteriocin-producing strain Enterococcus faecium ST5Ha was isolated from smoked salmon and identified by biomolecular techniques. Ent. faecium ST5Ha produces a pediocin-like bacteriocin with activity against several lactic acid bacteria, Listeria spp. and some other human and food pathogens, and remarkably against HSV-1 virus. Bacteriocin ST5Ha was produced at high levels in MRS broth at 30 degrees C and 37 degrees C, reaching a maximum production of 1.0 x 10(9) AU/ml, checked against Listeria ivanovii ATCC19119 as target strain and surrogate of pathogenic strain Listeria monocytogenes. The molecular weight of bacteriocin ST5Ha was estimated to be 4.5 kDa according to tricine-SDS-PAGE data. Ent. faecium ST5Ha harbors a 1.044 kb chromosomal DNA fragment fitting in size to that of pediocin PA-1/AcH. In addition, the sequencing of bacteriocin ST5Ha gene indicated 99% of DNA homology to pediocin PA-1/AcH. The combined application of low levels (below MIC) of ciprofloxacin and bacteriocin ST5Ha resulted in a synergetic effect in the inhibition of target strain L. ivanovii ATCC19119. Bacteriocin ST5Ha displayed antiviral activity against HSV-1, an important human pathogen, with a selectivity index of 173. To the best of our knowledge, this is the first report on Ent. faecium as a potential producer of pediocin-like bacteriocin with antiviral activity.

  10. Improved adsorption-desorption extraction applied to the partial characterization of the antilisterial bacteriocin produced by Carnobacterium maltaromaticum C2

    OpenAIRE

    Tulini,F. L; E.C.P De Martinis

    2010-01-01

    Bacteriocins are ribosomally produced peptides useful for food biopreservation. An improved adsorption-desorption process is proposed for the partial purification of the bacteriocin produced by the fish isolate Carnobacterium maltaromaticum C2. Analyzis of extract by SDS-PAGE indicated this method may offer an alternative to improve the yield of purification of bacteriocins.

  11. Improved adsorption-desorption extraction applied to the partial characterization of the antilisterial bacteriocin produced by Carnobacterium maltaromaticum C2.

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    Tulini, F L; De Martinis, E C P

    2010-04-01

    Bacteriocins are ribosomally produced peptides useful for food biopreservation. An improved adsorption-desorption process is proposed for the partial purification of the bacteriocin produced by the fish isolate Carnobacterium maltaromaticum C2. Analyzis of extract by SDS-PAGE indicated this method may offer an alternative to improve the yield of purification of bacteriocins.

  12. Improved adsorption-desorption extraction applied to the partial characterization of the antilisterial bacteriocin produced by Carnobacterium maltaromaticum C2

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    F. L Tulini

    2010-06-01

    Full Text Available Bacteriocins are ribosomally produced peptides useful for food biopreservation. An improved adsorption-desorption process is proposed for the partial purification of the bacteriocin produced by the fish isolate Carnobacterium maltaromaticum C2. Analyzis of extract by SDS-PAGE indicated this method may offer an alternative to improve the yield of purification of bacteriocins.

  13. Lactococcus lactis LMG2081 Produces Two Bacteriocins, a Nonlantibiotic and a Novel Lantibiotic.

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    Mirkovic, Nemanja; Polovic, Natalija; Vukotic, Goran; Jovcic, Branko; Miljkovic, Marija; Radulovic, Zorica; Diep, Dzung B; Kojic, Milan

    2016-04-01

    Bacteriocin producers normally possess dedicated immunity systems to protect themselves from their own bacteriocins.Lactococcus lactis strains LMG2081 and BGBM50 are known as lactococcin G producers. However, BGBM50 was sensitive to LMG2081, which indicated that LMG2081 might produce additional bacteriocins that are not present in BGBM50. Therefore, whole-genome sequencing of the two strains was performed, and a lantibiotic operon (called lctLMG) was identified in LMG2081 but not in BGBM50. The lctLMG operon contains six open reading frames; the first three genes,lmgA ,lmgM, and lmgT, are involved in the biosynthesis and export of bacteriocin, while the other three genes,lmgF,lmgE, and lmgG, are involved in lantibiotic immunity. Mutational analysis confirmed that the lctLMG operon is responsible for the additional antimicrobial activity. Specifically, site-directed mutation within this operon rendered LMG2081 inactive toward BGBM50. Subsequent purification and electrospray ionization-time of flight mass spectrometric analysis confirmed that the lantibiotic bacteriocin called lacticin LMG is exported as a 25-amino-acid peptide. Lacticin LMG is highly similar to the lacticin 481 group. It is interesting that a bacteriocin producer produces two different classes of bacteriocins, whose operons are located in the chromosome and a plasmid.

  14. 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 aga

  15. Characterization of some bacteriocins produced by lactic acid bacteria isolated from fermented foods.

    Science.gov (United States)

    Grosu-Tudor, Silvia-Simona; Stancu, Mihaela-Marilena; Pelinescu, Diana; Zamfir, Medana

    2014-09-01

    Lactic acid bacteria (LAB) isolated from different sources (dairy products, fruits, fresh and fermented vegetables, fermented cereals) were screened for antimicrobial activity against other bacteria, including potential pathogens and food spoiling bacteria. Six strains have been shown to produce bacteriocins: Lactococcus lactis 19.3, Lactobacillus plantarum 26.1, Enterococcus durans 41.2, isolated from dairy products and Lactobacillus amylolyticus P40 and P50, and Lactobacillus oris P49, isolated from bors. Among the six bacteriocins, there were both heat stable, low molecular mass polypeptides, with a broad inhibitory spectrum, probably belonging to class II bacteriocins, and heat labile, high molecular mass proteins, with a very narrow inhibitory spectrum, most probably belonging to class III bacteriocins. A synergistic effect of some bacteriocins mixtures was observed. We can conclude that fermented foods are still important sources of new functional LAB. Among the six characterized bacteriocins, there might be some novel compounds with interesting features. Moreover, the bacteriocin-producing strains isolated in our study may find applications as protective cultures.

  16. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  18. Ureaplasma urealyticum and Mycoplasma hominis sensitivity to bacteriocins produced by two Lactobacilli strains.

    Science.gov (United States)

    Daniele, M; Ruiz, F; Pascual, L; Barberis, L

    2011-10-01

    The purpose of the present study was to determine the inhibitory activities of two bacteriocins, produced by lactobacilli, against genital mycoplasmas. In this study, infections produced by genital mycoplasmas were studied; of these, 1.3% were caused by Mycoplasma hominis, 10.7% by Ureaplasma urealyticum and 5.6% by U. urealyticum + M. hominis. U. urealyticum was isolated from 75 out of 123 patients with genital mycoplasmas, while M. hominis was isolated from 9 patients (7.3%) and both U. urealyticum and M. hominis from 39 patients (31.7%). Bacteriocins, L23 and L60, produced by Lactobacillus fermentum and L. rhamnosus, respectively, appear to be two novel inhibitors of bacterial infection with potential antibacterial activity. Both bacteriocins proved to be active against 100% of strains tested; MICs of bacteriocin L23 ranged between 320 and 160 UA ml(-1) for 78% of the M. hominis strains and between 320 and 80 UA ml(-1) for 95% of the U. urealyticum strains. In addition, bacteriocin L60 was still active at 160 UA ml(-1) for a high percentage (56%) of M. hominis strains, and at 80 UA ml(-1) for 53% of the U. urealyticum strains. Interestingly, these antimicrobial substances produced by lactobacilli showed an inhibitory activity against genital mycoplasmas even when diluted. Altogether, our study indicates that the bacteriocins, L23 and L60, are good candidates for the treatment or prevention of genital infections in women.

  19. The study of effect bacteriocin producing Lactoco ccus lactis on Listeria monocytogenes and Bacillus cereus

    Directory of Open Access Journals (Sweden)

    M. Mirhossieni, M.Sc

    2007-01-01

    Full Text Available AbstractBackground and purpose: Dairy products often associated with problems such as short shelf life and poor hygiene control. A novel approach is to utilize bacteriocin or bacteriocin producer strains, to control undesirable micro flora as Listeria monocytogenes and Bacillus cereus in foods. Hence, we studied the effect of nisin like producing Lactococcus lactis against Listeria monocytogenes and Bacillus cereus, in order to compare the isolated strain within different countries.Materials and Methods: In this research we studied the effect of nisin like producing Lactococcus lactis, with producer spot test method. We also used supernatant from 24 h culture of Lactoccus lactis. Moreover, we studied the effect of bacteriocin on Listeria monocytogenes and Bacillus cereus growth curves.Results: The growth of both strains was inhibited by the bacteriocin. Conclusion: According to our results, the bacteriocin could be used in liquid food with bacteriocin added directly or as a starter culture in fermentation. This would inhibit the growth of Listeria monocytogenes; furthermore, Bacillus cereus is used to reduce food poisoning for fermented food products.

  20. In vitro Characterization of Bacteriocin Produced by Lactic Acid Bacteria Isolated from Nem Chua, a Traditional Vietnamese Fermented Pork.

    Science.gov (United States)

    Pilasombut, Komkhae; Rumjuankiat, Kittaporn; Ngamyeesoon, Nualphan; Duy, Le Nguyen Doan

    2015-01-01

    The aim of this study was to screen and In vitro characterize the properties of bacteriocin produced by lactic acid bacteria isolated from Vietnamese fermented pork (Nem chua). One hundred and fifty LAB were isolated from ten samples of Nem chua and screened for bacteriocin-producing lactic acid bacteria. Antimicrobial activity of bacteriocin was carried out by spot on lawn method against both gram positive and gram negative bacteria. One isolate, assigned as KL-1, produced bacteriocin and showed inhibitory activity against Lactobacillus sakei, Leuconostoc mesenteroides and Enterococcus faecalis. To characterize the bacteriocin-producing strain, optimum temperature, incubation period for maximum bacteriocin production and identification of bacteriocin-producing strain were determined. It was found that the optimum cultivation temperature of the strain to produce the maximum bacteriocin activity (12,800 AU/mL) was obtained at 30℃. Meanwhile, bacteriocin production at 6,400 AU/mL was found when culturing the strain at 37℃ and 42℃. The isolate KL-1 was identified as L. plantarum. Antimicrobial activity of cell-free supernatant was completely inhibited by proteolytic enzyme of trypsin, alpha-chymotrypsin and proteinase K. Bacteriocin activity was stable at high temperature up to 100℃ for 10 min and at 4℃ storage for 2 d. However, the longer heating at 100℃ and 4℃ storage, its activity was reduced.

  1. Isolation and characterization of bacteriocin-producing lactic acid bacteria from ready-to-eat food products.

    Science.gov (United States)

    Kelly, W J; Asmundson, R V; Huang, C M

    1996-12-01

    Lactic acid bacteria isolated from a range of foods sold in ready-to-eat form were screened for bacteriocin production. Twenty-two bacteriocin-producing cultures were isolated from 14 of the 41 foods sampled. Bacteriocin-producing isolates from meat, fish and dairy products were Lactobacillus and Leuconostoc species typically found associated with these products. Most of these isolates gave only a narrow inhibitory spectrum although two showed activity against Listeria monocytogenes. Fruit and vegetable products gave a broader range of organisms but most of the bacteriocin-producing cultures were found to be strains of Lactococcus. Several lactococci produced a nisin-like activity, and showed a broad inhibitory spectrum against the indicator strains tested. The ease with which bacteriocin-producing strains could be isolated implies that they are already being safely consumed in food, and highlights the potential for using bacteriocin-producing cultures for biopreservation, especially in association with minimally processed products.

  2. Improving safety of salami by application of bacteriocins produced by an autochthonous Lactobacillus curvatus isolate.

    Science.gov (United States)

    de Souza Barbosa, Matheus; Todorov, Svetoslav Dimitrov; Ivanova, Iskra; Chobert, Jean-Marc; Haertlé, Thomas; de Melo Franco, Bernadette Dora Gombossy

    2015-04-01

    The aims of this study were to isolate LAB with anti-Listeria activity from salami samples, characterize the bacteriocin/s produced by selected isolates, semi-purify them and evaluate their effectiveness for the control of Listeria monocytogenes during manufacturing of salami in a pilot scale. Two isolates (differentiated by RAPD-PCR) presented activity against 22 out of 23 L. monocytogenes strains for bacteriocin MBSa2, while the bacteriocin MBSa3 inhibited all 23 strains in addition to several other Gram-positive bacteria for both antimicrobials and were identified as Lactobacillus curvatus based on 16S rRNA sequencing. A three-step purification procedure indicated that both strains produced the same two active peptides (4457.9 Da and 4360.1 Da), homlogous to sakacins P and X, respectively. Addition of the semi-purified bacteriocins produced by Lb. curvatus MBSa2 to the batter for production of salami, experimentally contaminated with L. monocytogenes (10(4)-10(5) CFU/g), caused 2 log and 1.5 log reductions in the counts of the pathogen in the product after 10 and 20 days respectively, highlighting the interest for application of these bacteriocins to improve safety of salami during its manufacture.

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

    Directory of Open Access Journals (Sweden)

    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.

  4. Solution structures of the linear leaderless bacteriocins enterocin 7A and 7B resemble carnocyclin A, a circular antimicrobial peptide.

    Science.gov (United States)

    Lohans, Christopher T; Towle, Kaitlyn M; Miskolzie, Mark; McKay, Ryan T; van Belkum, Marco J; McMullen, Lynn M; Vederas, John C

    2013-06-11

    Leaderless bacteriocins are a class of ribosomally synthesized antimicrobial peptides that are produced by certain Gram-positive bacteria without an N-terminal leader section. These bacteriocins are of great interest due to their potent inhibition of many Gram-positive organisms, including food-borne pathogens such as Listeria and Clostridium spp. We now report the NMR solution structures of enterocins 7A and 7B, leaderless bacteriocins recently isolated from Enterococcus faecalis 710C. These are the first three-dimensional structures to be reported for bacteriocins of this class. Unlike most other linear Gram-positive bacteriocins, enterocins 7A and 7B are highly structured in aqueous conditions. Both peptides are primarily α-helical, adopting a similar overall fold. The structures can be divided into three separate α-helical regions: the N- and C-termini are both α-helical, separated by a central kinked α-helix. The overall structures bear an unexpected resemblance to carnocyclin A, a 60-residue peptide that is cyclized via an amide bond between the C- and N-termini and has a saposin fold. Because of synergism observed for other two-peptide leaderless bacteriocins, it was of interest to probe possible binding interactions between enterocins 7A and 7B. However, despite synergistic activity observed between these peptides, no significant binding interaction was observed based on NMR and isothermal calorimetry.

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

    Directory of Open Access Journals (Sweden)

    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.

  6. Enterococcus faecium RZS C5, an interesting bacteriocin producer to be used as a co-culture in food fermentation.

    Science.gov (United States)

    Leroy, F; Foulquié Moreno, M R; De Vuyst, L

    2003-12-01

    Enterocins, bacteriocins produced by enterococci, are gaining interest because of their industrial potential. Due to its bacteriocin production, Enterococcus faecium RZS C5, a natural cheese isolate, has a strong activity towards Listeria monocytogenes. For this reason, the strain may be applicable as a bacteriocin-producing co-culture in food fermentation in order to reduce the risk on Listeria outgrowth. The strain displays remarkable bacteriocin production kinetics. Whereas most lactic acid bacteria produce bacteriocin in a growth-associated way until the beginning of the stationary phase, bacteriocin production by E. faecium RZS C5 in MRS broth at controlled pH values below 7.5 is characterised by a boost of bacteriocin activity levels in the very early growth phase. In addition, bacteriocin production kinetics are closely linked to the environmental and cultural conditions. However, no straightforward statement about the effect of environmental stress on bacteriocin production can be made since the effect is dependent on the type of stress applied. Kinetic experiments in milk and on pilot scale, applying Cheddar cheese-making conditions, have indicated that the strain may be effective as a bacteriocin-producing co-culture. Further research is needed to evaluate the use of E. faecium RZS C5 as a co-culture for the production of fermented sausage.

  7. 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.

  8. Isolation and biochemical characterisation of a bacteriocin-like substance produced by Bacillus amyloliquefaciens An6.

    Science.gov (United States)

    Ayed, Hanen Ben; Maalej, Hana; Hmidet, Noomen; Nasri, Moncef

    2015-12-01

    This study focuses on the isolation and characterisation of a peptide with bacteriocin-like properties from Bacillus amyloliquefaciens An6. Incubation conditions were optimised, and the effects of the incubation period and of carbon and nitrogen sources were investigated. The produced bacteriocin was partially purified with ammonium sulphate precipitation, dialysis and ultrafiltration and was then biochemically characterised. Maximum bacteriocin production was achieved after 48h of incubation in a culture medium containing 20g/L starch and 10g/L yeast extract, with an initial pH 8.0 at 30°C under continuous agitation at 200rpm. The bacteriocin was sequentially purified and its molecular weight was determined to be 11kDa by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The bacteriocin was relatively heat-resistant and was not sensitive to acid and alkaline conditions (pH 4.0-10.0). Its inhibitory activity was sensitive to proteinase K but was resistant to the proteolytic action of alcalase, trypsin, chymotrypsin and pepsin. In conclusion, bacteriocin An6, owing its wide spectrum of activity as well as its high tolerance to acidic and alkaline pH values, temperature and proteases shows great potential for use as a food biopreservative.

  9. An evaluation and partial characterization of a bacteriocin produced by Lactococcus lactis subsp lactis ST1 isolated from goat milk

    Directory of Open Access Journals (Sweden)

    Parinaz Taheri

    2012-12-01

    Full Text Available A bacteriocin-like inhibitory substance producing Lactococcus lactis subsp lactis strain, ST1, isolated from goat milk of Iranian origin and with broad spectrum of activity and desirable technical properties was used for evaluating some futures of bacteriocin inhibitory activity. Cell growth and bacteriocin production studies were carried out in MRS medium incubated statically under uncontrolled pH condition. The antibacterial activity presented a primary metabolite pattern and showed a rapid decrease at the stationary phase. Microaerobiosis and capnophily growth conditions resulted in higher bacteriocin production while aerobiosis showed negative effect on both cell growth and bacteriocin production. Bacteriocin production, on the other hand, was favored in MRS broth (pH; 6.5 inoculated with 0.1 ml l-1 fresh culture when incubation was carried out at 30 °C. This indicated that the conditions resulted in higher levels of growth were frequently favoring bacteriocin production by ST1 as well. Decrease in activity, at the stationary growth phase, was much pronounced in favored growth condition. Nutrient depletion, deferent effect of low pH on bacteriocin production and/or protein degradation seemed more responsible for this phenomenon. The study also provided further data on new method for bacteriocin release from the cell wall of producer. It was clearly shown that both heating and ultrasound shock for 5 min at pH 2 could increase bacteriocin activity significantly. The release was more pronounced in the presence of 0.5% Tween80.

  10. Streptococcus thermophilus 580 produces a bacteriocin potentially suitable for inhibition of Clostridium tyrobutyricum in hard cheese.

    Science.gov (United States)

    Mathot, A G; Beliard, E; Thuault, D

    2003-10-01

    A strain of Streptococcus thermophilus that inhibits Clostridium tyrobutyricum has been isolated from raw milk. The active compound produced disappears after a treatment with protease. However, unlike most bacteriocins, it is not thermoresistant, and the activity is completely lost after 1 h at 60 degrees C. Its inhibitory spectrum is limited to other thermophilic streptococci, Brochothrix, and sporulated gram-positive rods. So this bacteriocin could be different from those already described. This bacteriocin-producing strain could be used in thermophilic starter for hard cheese making because the bacteriocin is not active against thermophilic lactobacilli. It is produced in M17 medium during the decreasing temperature phase of the hard cheese-making process temperature cycle and is also produced in milk. Moreover, when Streptococcus thermophilus was cocultured with a Lactobacillus delbrueckii subsp. lactis starter strain, it seems to enhance the bacteriocin production. However the level of activity always decreases drastically during the stationary phase. But inhibition of Clostridium tyrobutyricum spores can be obtained in small-scale curds.

  11. [Characteristics and identification of bacteriocins produced by Lactococcus lactis subsp. lactis 194-K].

    Science.gov (United States)

    Ustiugova, E A; Timofeeva, A V; Stoianova, L G; Netrusov, A I; Katrukha, G S

    2012-01-01

    The Lactococcus lactis subsp. lactis 194-K strain has been established to be able to produce two bacteriocins, one of which was identified as the known lantibiotic nisin A, and the other 194-D bacteriocin represents a polypeptide with a 2589-Da molecular mass and comprises 20 amino acid residues. Both bacteriocins were produced in varying proportions in all of the studied nutrient media, which support the growth of the producer. Depending on the cultivation medium, the nisin A content was 380- to 1123-fold lower in the 194-K stain culture fluid than that of the 194-D peptide. In comparision to to nisin A Bacteriocin 194-D possessed a wide range of antibacterial activity and suppressed the growth of both Gram-positive and Gram-negative bacteria. An optimal medium for 194-D bacteriocin synthesis was shown to be a fermentation medium which contained yeast extract, casein hydrolysate, and potassium phosphate. The biosynthesis ofbacteriocin 194-D by the 194-K strain in these media occurred parallel to producer growth, and its maximal accumulation in the culture fluid was observed at 14-20 h of the strain's growth.

  12. Inhibition of Listeria monocytogenes biofilms by bacteriocin-producing bacteria isolated from mushroom substrate.

    Science.gov (United States)

    Bolocan, A S; Pennone, V; O'Connor, P M; Coffey, A; Nicolau, A I; McAuliffe, O; Jordan, K

    2017-01-01

    This study was designed to investigate the ability of naturally occurring bacteria isolated from mushroom substrate to prevent biofilm formation by Listeria monocytogenes or to remove existing biofilms in mushroom production facilities. It is generally recognized that L. monocytogenes forms biofilms that can facilitate its survival in food-processing environments. Eleven bacteriocin-producing isolates were identified and the bacteriocins characterized based on heat and enzyme inactivation studies. Further characterization was undertaken by MALDI-TOF mass spectrometry, PCR and sequencing. Production of nisin Z (by Lactococcus lactis isolates), subtilomycin (by Bacillus subtilis isolates) and lichenicidin (by Bacillus licheniformis and Bacillus sonorensis isolates) was detected. In co-culture with L. monocytogenes, the bacteriocin-producing strains could prevent biofilm formation and reduce pre-formed biofilms. Mushroom substrate can be a source of bacteriocin-producing bacteria that can antagonize L. monocytogenes. The results highlight the potential of bacteriocin-producing strains from mushroom substrate to reduce L. monocytogenes biofilm in food production environments, contributing to a reduction in the risk of food contamination from the environment. © 2016 The Society for Applied Microbiology.

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

    Directory of Open Access Journals (Sweden)

    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

  14. 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.

  15. 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

  16. Inhibition of Propionibacterium acnes by Bacteriocin-Like Inhibitory Substances (BLIS) Produced by Streptococcus Salivarius

    Science.gov (United States)

    Bowe, Whitney P.; Filip, Jennifer C.; DiRienzo, Joseph M.; Volgina, Alla; Margolis, David J.

    2009-01-01

    We report the in vitro inhibition of Propionibacterium acnes (P. acnes) by a bacteriocin-like inhibitory substance (BLIS-like substance) produced by Streptococcus salivarius (S. salivarius). Bacteriocins are proteinaceous substances produced by bacteria that are capable of inhibiting the growth of similar bacterial strains. Unlike classical antibiotics, they have a relatively narrow spectrum of killing activity, resulting in a reduction in the intensity of selection for resistance. These findings suggest that BLIS may potentially be used for its anti-P. acnes activity in the treatment of acne. PMID:17039652

  17. Detection, partial purification and characterization of bacteriocin produced by Lactobacillus brevis FPTLB3 isolated from freshwater fish: Bacteriocin from Lb. brevis FPTLB3.

    Science.gov (United States)

    Banerjee, Shiba Prosad; Dora, Krushna Chandra; Chowdhury, Supratim

    2013-02-01

    Lactobacillus brevis FPTLB3 was isolated from freshwater fish, capable of producing bacteriocin that had broad spectrum of inhibition (3200 AU/ml) against Escherichia coli MTCC 1563, Enterococcus faecalis MTCC 2729, Lactobacillus casei MTCC 1423, Lactobacillus sakei ATCC 15521 and Staphylococcus aureus ATCC 25923. The antimicrobial activity of crude supernatant fluid was stable after heating at 121 °C for 60 min and declined thereafter. Stability of antimicrobial activity was observed at pH range of 2.0 to 8.0. Its active principle was proteinaceous in nature since the bacteriocin was inactivated by proteolytic enzymes, but not by other non-proteolytic enzymes. Mitomycin C and UV light did not affect the activity of the bacteriocin, while chloroform extraction completely destroyed their activity. Exposure to surfactant resulted in an increase in titre, except Nonidet P-40, which led to total loss of activity. No bacteriocin adsorption was detected at pH 1 to 2, whereas 100% bacteriocin adsorption was found at pH 6.5. Based on Tricine SDS-PAGE the estimated molecular mass of bacteriocin was 54 kDa. No plasmid was found to present in the isolate.

  18. Draft Genome Sequence of Carnobacterium divergens V41, a Bacteriocin-Producing Strain

    Science.gov (United States)

    Remenant, Benoît; Borges, Frédéric; Cailliez-Grimal, Catherine; Revol-Junelles, Anne-Marie; Marché, Laurent; Lajus, Aurélie; Médigue, Claudine; Pilet, Marie-France; Prévost, Hervé

    2016-01-01

    In this study, we present the draft genome sequence of Carnobacterium divergens V41. This strain was previously reported as producing divercin V41, a bacteriocin of interest for food biopreservation. Its genome revealed also the presence of a gene cluster putatively involved in polyketide production, which is unique in lactic acid bacteria. PMID:27738030

  19. Variable Characteristics of Bacteriocin-Producing Streptococcus salivarius Strains Isolated from Malaysian Subjects

    OpenAIRE

    Abdelahhad Barbour; Koshy Philip

    2014-01-01

    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 i...

  20. Genotyping by randomly amplified polymorphic DNA of bacteriocin producing Lactobacillus acidophilus strains from Nigeria.

    Science.gov (United States)

    Alli, John Adeolu; Iwalokun, Bamidele A; Oluwadun, Afolabi; Okonko, Iheanyi Omezuruike

    2015-01-01

    Yogurt and starter culture producers are still searching strains of Lactobacillus acidophilus to produce healthier yogurt with a longer shelf life and better texture, taste, and quality. This study determined the genotyping of bacteriocin producing Lactobacillus acidophilus strains recovered from Nigerian yogurts. Yogurt samples were collected from four different states of South West regions of Nigeria. Isolates were obtained from MRS Medium and biochemically characterized. This was further confirmed by API50CH. The bacteriocin positivity and activity was determined. Genomic characterization of our Lactobacillus acidophilus strains was done with randomly amplified polymorphic DNA-PCR. All yogurt samples containing Lactobacillus acidophilus strains meet the probiotic requirement of ≥10(6) cfu/mL. The gel picture revealed 6 RAPD clonal types of Lactobacillus acidophilus strains with RAPD type C observed to be more common. Significant differences existed in the mean growth inhibition zone (t = -7.32, P 0.05 Staphylococcus aureus). No correlation between the bacteriocin production, activity, and their RAPD clonal division (X(2) = 7.49, P = 0.1610, df = 5). In conclusion, L. acidophilus isolated in Nigeria samples met the probiotic requirements of ≥10(6) cfu/mL and produce bacteriocins with good spectrum of activity.

  1. Characterization of a bacteriocin produced by Enterococcus faecalis N1-33 and its application as a food preservative.

    Science.gov (United States)

    Hata, Tomomi; Alemu, Melaku; Kobayashi, Miho; Suzuki, Chise; Nitisinprasert, Sunee; Ohmomo, Sadahiro

    2009-03-01

    A bacteriocin-producing strain, N1-33, isolated from fermented bamboo shoot was identified as Enterococcus faecalis. The pH-adjusted culture supernatant of this strain consisted of several peptides with bacteriocin activity, and the supernatant inhibited the growth of pathogenic bacteria such as Listeria monocytogenes. The major peptide with bacteriocin activity was purified, and the first 39 amino acid residues of the bacteriocin were found to be identical to enterocin MR10A produced by E. faecalis MRR10-3. Addition of the pH-adjusted and concentrated culture supernatant of strain N1-33 caused a marked reduction in the growth of Bacillus cereus in custard cream and L. monocytogenes in pickled cucumber. These results suggest the potential use of the bacteriocin produced by strain N1-33 in food biopreservation.

  2. Isolation of a bacteriocin-producing lactococcus lactis and application of its bacteriocin to manage spoilage bacteria in high-value marine fish under different storage temperatures.

    Science.gov (United States)

    Sarika, A R; Lipton, A P; Aishwarya, M S; Dhivya, R S

    2012-07-01

    The bacteriocins of lactic acid bacteria have considerable potential for biopreservation. The Lactococcus lactis strain PSY2 (GenBank account no. JF703669) isolated from the surface of marine perch Perca flavescens produced antibacterial activity against pathogenic and spoilage-causing Gram-positive and Gram-negative bacteria viz. Arthrobacter sp., Acinetobacter sp., Bacillus subtilis, Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa and Staphylococcus aureus and possessed broad inhibitory spectrum. The biopreservative efficacy of the bacteriocin PSY2 was evaluated using fillets of reef cod, Epinephelus diacanthus. The fillets (10 g) were sprayed with 2.0 ml of 1,600 AU/ml bacteriocin, wrapped and kept under different storage temperatures viz., 4, 0 and -18 °C. The biopreservative extended the shelf-life of fillets stored at 4 °C to >21 days as against bacteriocin-treated samples stored for 21 days at 4 °C while the untreated samples became unacceptable by the 14th day. The biopreservative gave no significant effect at -18 °C. Thus, the bacteriocin derived from L. lactis PSY2 gave increased protection against spoilage bacteria and offers an alternative for the preservation of high-value sea foods.

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

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    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

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

    Science.gov (United States)

    Barbour, Abdelahhad; Philip, Koshy

    2014-01-01

    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. 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-morpholino)ethanesulfonic 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. 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 pharmaceuticals and probiotics from S. salivarius generating different

  5. Partial purification and characterization of bacteriocin produced by Enterococcus faecalis DU10 and its probiotic attributes.

    Science.gov (United States)

    Perumal, Venkatesh; Repally, Ayyanna; Dasari, Ankaiah; Venkatesan, Arul

    2016-10-01

    A novel bacteriocin produced by avian duck isolated lactic acid bacterium Enterococcus faecalis DU10 was isolated. This bacteriocin showed a broad spectrum of antibacterial activity against important food-borne pathogens and was purified by size exclusion chromatography followed by reverse-phase high-performance liquid chromatography in a C-18 column. Tricine-SDS PAGE revealed the presence of a band with an estimated molecular mass of 6.3 kDa. The zymogram clearly linked the antimicrobial activity with this band. This result was further confirmed by mass-assisted laser desorption ionization time-of-flight mass spectrometry, since a sharp peak corresponding to 6.313 kDa was detected and the functional groups were revealed by Fourier transform infrared spectroscopy. Bacteriocin DU10 activity was found sensitive to proteinase-K and pepsin and partially affected by trypsin and α-chymotrypsin. The activity of bacteriocin DU10 was partially resistant to heat treatments ranging from 30 to 90°C for 30 min. It also withstood a treatment at 121°C for 10 min. Cytotoxicity of bacteriocin DU10 by methyl-thiazolyl-diphenyl-tetrazolium bromide assay showed that the viability of HT-29 and HeLa cells decreased 60 ± 0.7% and 43 ± 4.8%, respectively, in the presence of 3,200 AU/mL of bacteriocin. The strain withstood 0.3% w/v of bile oxgall and pH 2 affected the bacterial growth between 2 and 4 hr of incubation. Adhesion properties examined with HT-29 cell line showed 69.85% initial population of strain E. faecalis DU10, which was found to be strongly adhered to this cell line. These results conclude bacteriocin DU10 may be used as a potential biopreservative and E. faecalis DU10 may be used as a potential probiont to control Salmonella infections.

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

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    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.

  7. Bacteriocin Inducer Peptides

    Science.gov (United States)

    Novel peptides produced by bacteriocin-producing bacteria stimulate the production of bacteriocins in vitro. The producer bacteria are cultured in the presence of a novel inducer bacteria and a peptide having a carboxy terminal sequence of VKGLT in order to achieve an increase in bacteriocin produc...

  8. The partial characterization of the antibacterial peptide bacteriocin G2 produced by the probiotic bacteria Lactobacillus plantarum G2

    Directory of Open Access Journals (Sweden)

    SVETLANA L. ŠEATOVIĆ

    2011-05-01

    Full Text Available The aim of this study was the partial characterization of the antimicrobial peptide bacteriocin G2 produced by probiotic bacteria Lactobacillus plantarum G2, which was isolated from a clinical sample of a healthy person. Antimicrobial substance was secreted in the supernatant of an L. plantarum G2 culture, and showed a diverse spectrum of antimicrobial activity of all the tested strains of the genera Lactobacillus and the pathogenic bacteria Staphylococcus aureus and Salmonella аbony. Isoelectric focusing revealed that bacteriocin G2 is a cationic peptide (pI about 10 with a molecular mass of 2.2 kDa according to tricine–sodium dodecyl sulphate–polyacrylamide gel electrophoresis, SDS-PAGE. The antimicrobial activity of bacteriocin G2 was diminished by the proteolytic action of trypsin and proteinase K. Bacteriocin G2 preserved its biological activity in the temperature range 40–60 °C (15 min, which was lost at 80 °C. Bacteriocin G2 was stable in the pH range 2–9, while treatment with 1 % Tween 80 and 1 % urea resulted in increased antimicrobial activity. The probiotic strain L. plantarum G2 produces the antimicrobial substance proteinaceous in nature with bacteriocin characteristics. Bacteriocin production is one of the key properties of probiotic bacteria with clinical potential as anti-infective agents, which will increase the likelihood of its in vivo efficacy.

  9. Physical chemical and biological characterization of a new bacteriocin produced byBacillus cereusNS02

    Institute of Scientific and Technical Information of China (English)

    Senbagam D; Gurusamy R; Senthilkumar B

    2013-01-01

    Objective:To screen the bacteriocinogenic isolate from buffalo milk and to characterize it on physical, chemical and biological aspects for the application in biopreservation.Methods:Bacillus cereus(B. cereus) was isolated and assessed for its baceteriocinogenic activity. Bacteriocin was produced and purified by ammonium sulphate precipitation, dialysis and gel filtration chromatography.Purified bacteriocin was used to check its antimicrobial activity against food borne bacteria.Effect and stability of bacteriocin was determined with the respect to temperature, pH, enzymes, organic solvents and chemicals.Bacteriocin was also subjected toSDSPAGE analysis to determine its molecular weight.In addition, functional groups exist in the bacteriocin was determined byFTIR analysis.Results:B. cereus was identified by16S rRNA sequence analysis.Bacteriocin showed increased activity against all the bacteria used and its activity unit was found to be51,200AU/mL.It was stable to high temperature(100 ℃) and wide range of pH(3-10), sensitive to proteolytic enzymes and resistant to nonproteolytic enzymes.It was low molecular weight(3.5 -6KDa) protein andFTIR study revealed the presence of amide group andNH stretching.Conclusions:Bacteriocin produced in this study possesses the highest antimicrobial activity against both gram positive and gram negative bacteria thereby it has immense application as biopreservative agent.FTIR proved its peptide nature.

  10. Isolation and purification of two bacteriocins 3D produced by Enterococcus faecium with inhibitory activity against Listeria monocytogenes.

    Science.gov (United States)

    Bayoub, Kaoutar; Mardad, Ilham; Ammar, Emna; Serrano, Aurelio; Soukri, Abdelaziz

    2011-02-01

    Strain 3D, isolated from fermented traditional Moroccan dairy product, and identified as Enterococcus faecium, was studied for its capability to produce two bacteriocins acting against Listeria monocytogenes. Bacteriocins 3 Da and 3Db were heat stable inactivated by proteinase K, pepsin, and trypsin but not when treated with catalase. The evidenced bacteriocins were stable in a wide pH range from 2 to 11 and bactericidal activity was kept during storage at 4°C. However, the combination of temperature and pH exhibited a stability of the bacteriocins. RP-HPLC purification of the anti-microbial compounds shows two active fractions eluted at 16 and 30.5 min, respectively. Mass spectrometry analysis showed that E. faecium 3D produce two bacteriocins Enterocin 3 Da (3893.080 Da) and Enterocin 3Db (4203.350 Da). This strain is food-grade organism and its bacteriocins were heat-stable peptides at basic, neutral, and acid pH: such bacteriocins may be of interest as food preservatives.

  11. Complete genome sequence of Lactobacillus paraplantarum L-ZS9, a probiotic starter producing class II bacteriocins.

    Science.gov (United States)

    Liu, Lei; Li, Pinglan

    2016-03-20

    Lactobacillus paraplantarum L-ZS9 is a probiotic starter isolated from fermented sausage and it is a great producer of class II bacteriocins. To the best of our knowledge, this is the first complete sequenced genome of L. paraplantarum deposited in GenBank database. The size of the complete genome of L. paraplantarum L-ZS9 is 3,139,729 bp. The genomic sequence revealed that this strain includes 19 genes involved in class II bacteriocins production and regulation. The information fill the gaps of the L. paraplantarum genome information and contribute to the improvement of class II bacteriocins research.

  12. 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.

  13. Antibacterial Activity of Selected Standard Strains of Lactic Acid Bacteria Producing Bacteriocins – Pilot Study

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    Malgorzata Bodaszewska-Lubas

    2012-10-01

    Full Text Available  Introduction:In this paper, an attempt was made to evaluate the antibacterial potential of standard strains of lactic acid bacteria (LAB producing bacteriocins of various classes, thus demonstrating various mechanisms of cell membrane damages against the Streptococcus agalactiae strains (Group B Streptococcus, GBS, depending on surface polysaccharides and surface alpha-like protein genes.Materials/Methods:Antimicrobial property of the strains of L. plantarum C 11, L. sakei DSMZ 6333, and L. lactis ATCC 11454 producing bacteriocins: JK and EF plantaricins, sakacin and nisin, respectively, against the GBS strains was evaluated. The chosen to the study GBS strains were represented by serotypes Ia, Ib, II, III, V and they had bca, epsilon, rib, alp2 or alp3 alpha-like protein genes. The experiment was conducted by means of suspension culture and the bacteria count was determined using the serial dilution method.Results:A great ability of L. plantarum C 11 strain was proven to inhibit the GBS growth. The strain of L. sakei DSMZ 6333 did not demonstrate any ability to inhibit the growth of GBS, whereas L. lactis ATCC 11454 inhibited the growth of S. agalactiae indicator strains to a minor extent. Statistically significant differences were demonstrated between the GBS strains representing various serotypes against the antimicrobial activity of model LAB strains. The least sensitive to the activity of bacteriocins were the strains representing serotypes Ib and III, whereas the strains representing serotype II were the most sensitive. The sensitivity of the GBS strains to the antimicrobial activity of LAB was not dependent on alpha-like protein genes.Discussion:Among the LAB standard strains producing bacteriocins, the strongest antimicrobial property was observed in the strain of L. plantarum C 11. Because of the generally known and verified strong antagonistic property of the strains of L. plantarum species against indicator bacteria, it is necessary

  14. Isolation, screening and characterization of bacteriocin-producing lactic acid bacteria isolated from traditional fermented food.

    Science.gov (United States)

    El-Shafei, H A; Abd-El-Sabour, H; Ibrahim, N; Mostafa, Y A

    2000-03-01

    100 lactic acid bacterial strains isolated from traditional fermented foods (yoghurt, milk cream, sour dough and milk) were screened for bacteriocin production. Twenty six strains producing a nisin-like bacteriocin were selected. Most of these isolates gave only a narrow inhibitory spectrum, although one showed a broad inhibitory spectrum against the indicator strains tested, this strain was determined as Lactococcus lactis. The influence of several parameters on the fermentative production of nisin by Lactococcus lactis was studied. Production of nisin was optimal at 30 degrees C and in the pH range 5.5-6.3. The effect of different sulphur and nitrogen sources on Lactococcus lactis growth and nisin production was studied. Magnesium sulfate and manganese sulfate were found to be the best sulphur sources while triammonium citrate was the best inorganic nitrogen source and meat extract, peptone and yeast extract were the best organic nitrogen source for nisin production.

  15. Streptococcus rattus strain BHT produces both a class I two-component lantibiotic and a class II bacteriocin.

    Science.gov (United States)

    Hyink, Otto; Balakrishnan, Mayooran; Tagg, John R

    2005-11-15

    Streptococcus rattus strain BHT is a species representative and strong bacteriocin producer. Here we report that S. rattus BHT produces two quite different types of bacteriocin activity, named BHT-A and BHT-B. The two bacteriocins were purified and analysed for activity and by MALDI-TOF mass spectrophotometry. BHT-A was found to be a variant of the two-component lantibiotic, Smb. BHT-B is a non-modified 5195Da peptide with some similarity to the tryptophan-rich Staphylococcus aureus bacteriocin, aureocin A53. Six S. rattus and two S. mutans strains were found to contain both the BHT-A and BHT-B genetic loci.

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

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    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. Partial characterization of bacteriocins produced by two Lactobacilus strains with probiotic properties.

    Science.gov (United States)

    Uymaz, Başar; Akkoç, Nefise; Akçelik, M

    2011-03-01

    The probiotic characteristics of Lactobacillus brevis BG18 and Lb. plantarum BG33, isolated from traditional Turkish Tulum cheese were assessed. These two bacteriocinproducer strains exhibited good probiotic characteristics such as resistance in media containing 0.3% bile salt, pepsin (3 mg mL⁻¹), and pancreatine (1 mg mL⁻¹) as well as acid resistance at pH 2. They were also adhered to Caco-2 epithelial cells in a manner comparable to Escherichia coli LMG3083 (ETEC) and Salmonella Typhimurium SL1344. The strains produced a heat-stable antimicrobial compound that was shown to be proteinaceous in nature, and therefore, referred to as bacteriocins. The bacteriocins were able to inhibit growth of a number grampositive bacteria such as Listeria monocytogenes, Clostridium botulinum, Staphylococcus aureus and Bacillus cereus. Tricine-SDS-PAGE of the active fraction resulted in single bands with estimated molecular masses of 2.5 kDA and 2.7 kDA for Lb. brevis BG18 and Lb. plantarum BG33 bacteriocins, respectively.

  18. Bacteriocins produced by wild Lactococcus lactis strains isolated from traditional, starter-free cheeses made of raw milk.

    Science.gov (United States)

    Alegría, Angel; Delgado, Susana; Roces, Clara; López, Belén; Mayo, Baltasar

    2010-09-30

    Sixty bacterial strains were encountered by random amplification of polymorphic DNA (RAPD) and repetitive extragenic palindromic (REP) typing in a series of 306 Lactococcus lactis isolates collected during the manufacturing and ripening stages of five traditional, starter-free cheeses made from raw milk. Among the 60 strains, 17 were shown to produce bacteriocin-like compounds in both solid and liquid media. At a genotypic level, 16 of the strains were identified by molecular methods as belonging to L. lactis subsp. lactis and one to L. lactis subsp. cremoris. Among the L. lactis subsp. lactis strains, phenotypic and genetic data determined that eleven produced either nisin A (nine strains) or nisin Z (two strains), and that five produced lactococcin 972. Variable levels of the two bacteriocins were produced by different strains. In addition, nisin was shown to be produced in inexpensive, dairy- and meat-based media, which will allow the practical application of its producing strains in industrial processes. Specific PCR and nucleotide and deduced amino acid sequence analysis identified the inhibitor produced by the single L. lactis subsp. cremoris isolate as a lactococcin G-like bacteriocin. Beyond the use of bacteriocins as functional ingredients for the biopreservation of foods, the newly identified bacteriocin-producing L. lactis strains from traditional cheeses may also be useful for designing starter cultures with protective properties and/or adjunct cultures for accelerating cheese ripening.

  19. 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.

  20. Characterization of putative class II bacteriocins identified from a non-bacteriocin-producing strain Lactobacillus casei ATCC 334.

    Science.gov (United States)

    Kuo, Yang-Cheng; Liu, Cheng-Feng; Lin, Jhao-Fen; Li, An-Chieh; Lo, Ta-Chun; Lin, Thy-Hou

    2013-01-01

    Several putative class II bacteriocin-like genes were identified in Lactobacillus casei ATCC 334, all of which might encode peptides with a double-glycine leader. Six peptides encoded by these genes were heterologously expressed in Escherichia coli and then partially purified in order to test their bacteriocin activity. The results revealed that the mature LSEI_2163 peptide was a class IId bacteriocin that exhibited antimicrobial activity against some lactobacilli and several Listeria species. Similarly, mature LSEI_2386 was a putative pheromone peptide that also had significant bacteriocin activity against several Listeria species. The activities of both peptides tolerated 121°C for 30 min but not treatment with proteinase K or trypsin. The two Cys residues located at positions 4 and 24 in the mature LSEI_2163 peptide were shown by mass spectrometry to form a disulfide bridge, which was required for optimal antibacterial activity. However, replacement of one or both Cys with Ser would cause significant reduction of the antibacterial activity, the reduction being greater when only one of the Cys residues (C4S) was replaced than when both (C4S/C24S) were replaced.

  1. 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

    A wide range of lactic acid bacteria (LAB) produce bacteriocins mainly active against other closely related LAB, but some bacteriocins are also active against the food-borne pathogen Listeria monocytogenes. With the aim of increasing food safety it has thus been considered to utilise bacteriocins...... 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...... to plantaricins and organic acids. In conclusion, the present study represents the first demonstration of the ability of a bacteriocin-producing LAB to dissipate the proton gradient of sessile and planktonic L. monocytogenes....

  2. Characterization of a bacteriocin produced by Lactobacillus sakei R1333 isolated from smoked salmon.

    Science.gov (United States)

    Todorov, Svetoslav D; Rachman, Cinta; Fourrier, Angélique; Dicks, Leon M T; van Reenen, Carol A; Prévost, Herve; Dousset, Xavier

    2011-02-01

    Strain R1333, isolated from commercially available smoked salmon, was identified as Lactobacillus sakei based on biochemical tests, sugar fermentation reactions (API 50 CHL), PCR with species-specific primers and sequencing of the 16S rRNA gene. Strain R1333 produces a 3811 kDa class IIa bacteriocin, active against Streptococcus caprinus, Streptococcus macedonicus, Streptococcus spp., L. sakei, Lactococcus lactis subsp. lactis, Listeria innocua, Listeria ivanovii subsp. ivanovii and Listeria monocytogenes. The mode of activity against L. innocua 2030C and L. ivanovii subsp. ivanovii ATCC 19119 was bactericidal, resulting in cell lysis and enzyme- and DNA-leakage. The highest level of activity (1600 AU/mL) was recorded when cells were grown at 30°C in MRS broth (initial pH 6.5). Only 800 AU/mL was recorded when strain R1333 was grown in MRS without Tween 80. Lower levels of bacteriocin production were recorded when strain R1333 was grown in MRS at 20°C. Peptide R1333 adsorbs at low levels (200 AU/mL) to producer cells. Purification of bacteriocin R1333 was performed by 60% ammonium sulfate precipitation, followed by separation on a SepPak C(18) column and reverse-phase HPLC on a Nucleosil C(18) column with a linear gradient from 0.1% TFA to 90% acetonitryl. A molecular mass of 3811 kDa was determined by mass spectrometry. Based on mass spectrometry and sequencing of the PCR amplified fragment targeting the sakG gene, L. sakei R1333 is a potential producer of sakacin G. This is the first report of the identification of sakacin G produced by L. sakei isolated from smoked salmon.

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

    Science.gov (United States)

    Kumari, Archana; Akkoç, Nefise; Akçelik, Mustafa

    2012-04-01

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

  4. 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.

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

    Science.gov (United States)

    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 bacteriocin production was observed in MRS broth when inulin (3,200 AU/ml) or oligofructose (2,400 AU/ml) was used instead of glucose (6,400 AU/ml). L. sakei 1 adhered to Caco-2 cells, and its cell-free pH-neutralized supernatant containing sakacin 1 led to a significant reduction of in vitro listerial invasion of human intestinal Caco-2 cells.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. CHARACTERISTICS OF BACTERIOCIN BA28 PRODUCED BY Pediococcus acidilactici BA28

    Directory of Open Access Journals (Sweden)

    Kaur Baljinder

    2013-01-01

    Full Text Available Peptic ulcers are produced by an imbalance between gastro-duodenal mucosal defense mechanisms and damaging forces of gastric acid and pepsin, combined with superimposed injury from environmental or immunologic agents. Most common symptoms of peptic ulcer disease are abdominal discomfort, gnawing ache, occurs 2 to 3 hours after meal, other symptoms includes weight loss, poor appetite, bloating, nausea, vomiting etc. Some time duodenal wall perforates; bleeding due to the ulcer breaks blood vessels and obstructs the path of food trying to leave the stomach. Various studies have shown the association of Helicobacter pylori with peptic ulcers. Probiotic lactic acid bacteria are proposed to cure peptic ulcers by reducing colonization of H. pylori with stomach wall and by eradicating already established infection. A bacteriocin producing probiotic strain of P. acidilactici BA28 was evaluated for its antimicrobial activity against a number of Gram-positive and Gram-negative pathogens. Bacteriocin BA28 was partially purificated and characterized following in vitro assays. Preliminary investigations against H. plyori have suggested its effectiveness against peptic ulcer disease and therefore could be exploited to develop novel therapeutics.

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

    Directory of Open Access Journals (Sweden)

    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.

  9. Purification and genetic characterisation of the novel bacteriocin LS2 produced by the human oral strain Lactobacillus salivarius BGHO1.

    Science.gov (United States)

    Busarcevic, Milos; Dalgalarrondo, Michèle

    2012-08-01

    The aim of this study was to investigate the antimicrobial potential of Lactobacillus salivarius BGHO1, a human oral strain with probiotic characteristics and a broad inhibitory spectrum both against Gram-positive and Gram-negative pathogens. Here we present the bacteriocin LS2, an extremely pH- and heat-stable peptide with antilisterial activity. LS2 is a novel member of the class IId bacteriocins, unique among all currently characterised bacteriocins. It is somewhat similar to putative bacteriocins from several oral streptococci, including the cariogenic Streptococcus mutans. LS2 is a 41-amino-acid, highly hydrophobic cationic peptide of 4115.1Da that is sensitive to proteolytic enzymes. LS2 was purified from cells of strain BGHO1 by solvent extraction and reverse-phase chromatography. Mass spectrometry was used to determine the molecular mass of the purified peptide. N-terminal amino acid sequencing enabled identification of the LS2 structural gene bacls2 by a reverse genetics approach. Downstream of the bacls2 gene, two bacteriocin-like genes were found, named blp1a and blp1b, and one putative bacteriocin immunity gene named bimlp. We also present the identification of the 242-kb megaplasmid pMPHO1 by pulsed-field gel electrophoresis, which harbours the genes bacls2, blp1a, blp1b and bimlp. Two peptides with antimicrobial activity, whose approximate sizes corresponded to those of blp1a and blp1b, were identified only after culturing strain BGHO1 in a chemically defined medium. This study demonstrated the capacity of Lactobacillus salivarius BGHO1 to produce multiple bacteriocins and further established this strain as a promising probiotic candidate. Copyright © 2012 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  10. C55 bacteriocin produced by ETB-plasmid positive Staphylococcus aureus strains is a key factor for competition with S. aureus strains.

    Science.gov (United States)

    Kawada-Matsuo, Miki; Shammi, Fariha; Oogai, Yuichi; Nakamura, Norifumi; Sugai, Motoyuki; Komatsuzawa, Hitoshi

    2016-03-01

    Exfoliative toxin (ET) produced by Staphylococcus aureus is closely associated with the onset of bullous impetigo. To date, three ETs (ETA, ETB and ETD) have been identified. The gene encoding ETB is located in a plasmid designated pETB. Bacteriocin synthesis genes are also located in this plasmid and pETB-positive strains reportedly produce the C55 bacteriocin. In this study, the antibacterial activity against S. aureus strains of the bacteriocin produced by the pETB-positive strain TY4 was investigated. This bacteriocin demonstrated antibacterial activity against all pETB-negative but not pETB-positive strains, including TY4. Additionally, a TY4- strain from which the pETB plasmid had been deleted exhibited susceptibility to the bacteriocin. Further experiments revealed that two immunity factors (orf 46-47 and orf 48) downstream of the bacteriocin synthesis genes in the pETB plasmid are associated with immunity against the bacteriocin produced by TY4. The TY4- with orf46-47 strain exhibited complete resistance to bacteriocin, whereas the TY4- with orf48 strain exhibited partial resistance. Whether bacteriocin affects the proportion of each strain when co-cultured with S. aureus strains was also investigated. When TY4 or TY4- was co-cultured with 209P strain, which is susceptible to the bacteriocin, the proportion of 209P co-cultured with TY4 was significantly less than when 209P was co-cultured with TY4-, whereas the proportion of TY4- with orf46-48 co-cultured with TY4 was greater than with TY4-. These results suggest that the C55 bacteriocin produced by pETB-positive strains affects the proportion of each strain when pETB-positive and -negative strains co-exist. © 2016 The Societies and John Wiley & Sons Australia, Ltd.

  11. 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.

  12. Partial Characterization of an Anti-Candida albicans Bacteriocin Produced by a Marine Strain of Bacillus sp., Sh10

    Directory of Open Access Journals (Sweden)

    Fatemeh Shayesteh

    2015-09-01

    Full Text Available The bacteriocin-producing strain Bacillus sp., Sh10, isolated from the marine environment, exhibited a broad spectrum of antimicrobial activity against different food spoilage and human pathogens, with a maximum inhibitory activity against Candida albicans. The inhibitory compound was sensitive to trypsin but resistant to proteinase K, lysozyme, lipase and &alpha-amylase. It was heat-stable and remained its activity after autoclaving. In addition, the antimicrobial substance demonstrated striking stability at low temperatures (4 and -20°C for up to one year and retained its activity in a wide pH range from 2 to 11. It was also stable and active in the presence of different surfactants, solvents and heavy metals. Analysis of the partially purified bacteriocin by SDS-PAGE showed an apparent molecular weight of ~11 KDa. This study reveals a remarkable potential of this bacteriocin to be used as a food preservative.

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

    Science.gov (United States)

    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.

  14. Outgrowth inhibition of Clostridium beijerinckii spores by a bacteriocin-producing lactic culture in ovine milk cheese.

    Science.gov (United States)

    Garde, Sonia; Avila, Marta; Arias, Ramón; Gaya, Pilar; Nuñez, Manuel

    2011-10-17

    In the manufacture of model cheeses, ovine milk was deliberately contaminated with spores of Clostridium beijerinckii INIA 63, a wild isolate from Manchego cheese with late blowing defect, and inoculated with nisin- and lacticin 481-producing Lactococcus lactis subsp. lactis INIA 415 as starter, to test its potential to prevent the late blowing defect, or with L. lactis subsp. lactis INIA 415-2, a spontaneous mutant not producing bacteriocins. Cheeses made individually with the lactococcal strains, without clostridial spores, served as controls. Cheese made with clostridial spores and L. lactis subsp. lactis INIA 415-2 showed late blowing defect after 120days of ripening. Spoilt cheese also showed lower concentrations of lactic acid, and higher levels of acetic, propionic and butyric acids, and of other volatile compounds such as 2-propanol and 1-butanol, than control cheese. In addition, cheese made with the bacteriocin producer did not show any late blowing symptoms, despite its spore counts similar to those of blown cheese, pointing to outgrowth inhibition of C. beijerinckii spores by bacteriocins. Besides, cheese made with the bacteriocin producer showed similar concentrations of lactic acid and volatile compounds than control cheese. Inclusion of L. lactis subsp. lactis INIA 415 in starter cultures seems a feasible method to prevent late blowing defect in cheese without altering its sensory characteristics.

  15. Antimicrobial activity of bacteriocin-producing lactic acid bacteria isolated from cheeses and yogurts

    Science.gov (United States)

    2012-01-01

    The biopreservation of foods using bacteriocinogenic lactic acid bacteria (LAB) isolated directly from foods is an innovative approach. The objectives of this study were to isolate and identify bacteriocinogenic LAB from various cheeses and yogurts and evaluate their antimicrobial effects on selected spoilage and pathogenic microorganisms in vitro as well as on a food commodity. LAB were isolated using MRS and M17 media. The agar diffusion bioassay was used to screen for bacteriocin or bacteriocin-like substances (BLS) producing LAB using Lactobacillus sakei and Listeria innocua as indicator organisms. Out of 138 LAB isolates, 28 were found to inhibit these bacteria and were identified as strains of Enterococcus faecium, Streptococcus thermophilus, Lactobacillus casei and Lactobacillus sakei subsp. sakei using 16S rRNA gene sequencing. Eight isolates were tested for antimicrobial activity at 5°C and 20°C against L. innocua, Escherichia coli, Bacillus cereus, Pseudomonas fluorescens, Erwinia carotovora, and Leuconostoc mesenteroides subsp. mesenteroides using the agar diffusion bioassay, and also against Penicillium expansum, Botrytis cinerea and Monilinia frucitcola using the microdilution plate method. The effect of selected LAB strains on L. innocua inoculated onto fresh-cut onions was also investigated. Twenty percent of our isolates produced BLS inhibiting the growth of L. innocua and/or Lact. sakei. Organic acids and/or H2O2 produced by LAB and not the BLS had strong antimicrobial effects on all microorganisms tested with the exception of E. coli. Ent. faecium, Strep. thermophilus and Lact. casei effectively inhibited the growth of natural microflora and L. innocua inoculated onto fresh-cut onions. Bacteriocinogenic LAB present in cheeses and yogurts may have potential to be used as biopreservatives in foods. PMID:22963659

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

    Directory of Open Access Journals (Sweden)

    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.

  17. 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.

  18. In Vitro Evaluation of Bacteriocin-Like Inhibitory Substances Produced by Lactic Acid Bacteria Isolated During Traditional Sicilian Cheese Making

    Science.gov (United States)

    Macaluso, Giusi; Fiorenza, Gerlando; Gaglio, Raimondo; Mancuso, Isabella

    2016-01-01

    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 (a-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.

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

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    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.

  20. Purification and characterization of plantaricin 163, a novel bacteriocin produced by Lactobacillus plantarum 163 isolated from traditional Chinese fermented vegetables.

    Science.gov (United States)

    Hu, Meizhong; Zhao, Haizhen; Zhang, Chong; Yu, Jiansheng; Lu, Zhaoxin

    2013-11-27

    Presumptive lactic acid bacteria (LAB) strains isolated from traditional Chinese fermented vegetables were screened for bacteriocin production. A novel bacteriocin-producing strain, Lactobacillus plantarum 163, was identified on the basis of its physiobiochemical characteristics and characterized by 16S rDNA sequencing. The novel bacteriocin, plantaricin 163, produced by Lb. plantarum 163 was purified by salt precipitation, gel filtration, and reverse-phase high-performance liquid chromatography (RP-HPLC). Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) analysis of plantaricin 163 revealed the molecular weight to be 3553.2 Da. The complete amino acid sequence showed VFHAYSARGNYYGNCPANWPSCRNNYKSAGGK, and no similarity to known bacteriocins was found. Plantaricin 163 was highly thermostable (20 min, 121 °C), active in the presence of acidic pH (3-5), sensitive to protease, and exhibited broad-spectrum antimicrobial activity against LAB and other tested Gram-positive and Gram-negative bacteria. The results suggest that plantaricin 163 may be employed as a biopreservative in the food industry.

  1. Use of Lactobacillus plantarum LPCO10, a Bacteriocin Producer, as a Starter Culture in Spanish-Style Green Olive Fermentations

    Science.gov (United States)

    Ruiz-Barba, J. L.; Cathcart, D. P.; Warner, P. J.; Jiménez-Díaz, R.

    1994-01-01

    Bacteriocin-producing Lactobacillus plantarum LPCO10 and its non-bacteriocin-producing, bacteriocinimmune derivative, L. plantarum 55-1, were evaluated separately for growth and persistence in natural Spanish-style green olive fermentations. Both strains were genetically marked and selectively enumerated using antibiotic-containing media. Plasmid profile and bacteriocin production (bac+) were used as additional markers. When olive brines were inoculated at 105 CFU/ml, the parent strain, LPCO10, proliferated to dominate the epiphytic microflora, sharing high population levels with other spontaneously occurring lactobacilli and persisting throughout the fermentation (12 weeks). In contrast, the derivative strain could not be isolated after 7 weeks. Stability of both plasmid profile and bac+ (LPCO10 strain) or bac- (55-1 strain) phenotype was shown by L. plantarum LPCO10 and L. plantarum 55-1 isolated throughout the fermentation. Bacteriocin activity could be found in the L. plantarum LPCO10-inoculated brines only after ammonium sulfate precipitation and concentration (20 times) of the final brine. Spontaneously occurring lactobacilli and lactic coccus populations, which were isolated from each of the fermenting brines studied during this investigation, were shown to be sensitive to the bacteriocins produced by L. plantarum LPCO10 when tested by the drop diffusion test. The declines in both pH and glucose levels throughout the fermentative process were similar in L. plantarum LPCO10- and in L. plantarum 55-1-inoculated brines and were comparable to the declines in the uninoculated brines. However, the final concentration of lactic acid in L. plantarum LPCO10-inoculated brines was higher than in the L. plantarum 55-1-inoculated brines and uninoculated brines. These results indicated that L. plantarum LPCO10 may be useful as a starter culture to control the lactic acid fermentation of Spanish-style green olives. PMID:16349291

  2. Isolation and partial characterization of a bacteriocin produced by Lactobacillus plantarum BM-1 isolated from a traditionally fermented Chinese meat product.

    Science.gov (United States)

    Zhang, Hongxing; Liu, Li; Hao, Yanling; Zhong, Siqiong; Liu, Hui; Han, Tao; Xie, Yuanhong

    2013-11-01

    Lactobacillus plantarum BM-1 isolated from a traditionally fermented Chinese meat product was found to produce a novel bacteriocin that is active against a wide range of gram-positive and gram-negative bacteria. Production of the bacteriocin BM-1 started early in the exponential phase and its maximum activity (5120 AU/mL) was recorded early during the stationary phase (16 hr). Bacteriocin BM-1 is sensitive to proteolytic enzymes but stable in the pH range of 2.0-10.0 and heat-resistant (15 min at 121°C). This bacteriocin was purified through pH-mediated cell adsorption-desorption and cation-exchange chromatography on an SP Sepharose Fast Flow column. The molecular weight of the purified bacteriocin BM-1 was determined to be 4638.142 Da by electrospray ionization Fourier transform mass spectrometry. Furthermore, the N-terminal amino acid sequence was obtained through automated Edman degradation and found to comprise the following 15 amino acid residues: H2 N-Lys-Tyr-Tyr-Gly-Asn-Gly-Val-Tyr-Val-Gly-Lys-His-Ser-Cys-Ser. Comparison of this sequence with that of other bacteriocins revealed that bacteriocin BM-1 contains the consensus YGNGV amino acid motif near the N-terminus. Based on its physicochemical characteristics, molecular weight, and N-terminal amino acid sequence, plantaricin BM-1 is a novel class IIa bacteriocin.

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

    Science.gov (United States)

    Sharma, Nivedita; Gupta, Anupama; Gautam, Neha

    2014-01-01

    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.

  4. Characterization of Bacteriocin like inhibitory substance produced by a new Strain Brevibacillus borstelensis AG1 Isolated from ‘Marcha’

    Science.gov (United States)

    Sharma, Nivedita; Gupta, Anupama; Gautam, Neha

    2014-01-01

    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. PMID:25477937

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

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    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.

  6. Class IIa Bacteriocins: Current Knowledge and Perspectives

    Science.gov (United States)

    Belguesmia, Yanath; Naghmouchi, Karim; Chihib, Nour-Eddine; Drider, Djamel

    Lactic acid bacteria (LAB) are known to produce antibacterial peptides and small proteins called bacteriocins, which enable them to compete against other bacteria in the environment. Bacteriocins fall structurally and chemically into three different classes, I, II, and III. Bacteriocins are ribosomally synthesized peptides with antagonism against closely related bacteria. This late observation has evolved because bacteriocins active against Gram-negative bacteria have recently been reported. Members of class IIa bacteriocins, referred to as pediocin-like bacteriocins, are among the most studied bacteriocins. This chapter is aimed at providing an updated review on the biology of class IIa bacteriocins.

  7. Behavior of Listeria monocytogenes and Staphylococcus aureus in yogurt fermented with a bacteriocin-producing thermophilic starter.

    Science.gov (United States)

    Benkerroum, Noreddine; Oubel, Hafida; Mimoun, Lamiae Ben

    2002-05-01

    Streptococcus salivarius subsp. thermophilus B producing a bacteriocin active against Listeria monocytogenes ATCC 7644 and Staphylococcus aureus SAD 30 was isolated from bakery yeast. The bacteriocin was partially purified by an adsorption/desorption technique, and its spectrum of action was compared to that of a neutralized cell-free supernatant (CFS). Although the CFS inhibited a number of gram-positive and -negative bacteria of health and spoilage significance, the spectrum of action of the partially purified bacteriocin was limited to gram-positive bacteria. L. monocytogenes was the most sensitive to both preparations. The bacteriocin-producing streptococcal strain was used in combination with a Bac- Lactobacillus delbrueckii subsp. bulgaricus CY strain isolated from commercial yogurt to assess the effectiveness of the resulting thermophilic starter in controlling L. monocytogenes and S. aureus in yogurt during fermentation and storage at refrigeration (ca. 7 degrees C) or abuse (ca. 22 degrees C) temperature. Yogurt samples were contaminated with L. monocytogenes or S. aureus to the approximate levels of 10(3) and 10(6) CFU/ml of milk, respectively. The results showed that in situ bacteriocin production was more active against L. monocytogenes than against S. aureus in vitro and in contaminated samples. While L. monocytogenes leveled off below the detectable limit in a 1-ml sample of yogurt within 24 h of processing, S. aureus survived in Bac+ and Bac- samples during 10 days of storage at room temperature (ca. 22 degrees C). Use of a Bac+ starter resulted in a 5-day extension of the shelf life.

  8. Effects of the bacteriocin PsVP-10 produced by Pseudomonas sp. on sensitive bacterial strains.

    Science.gov (United States)

    Padilla, Carlos; Lobos, Olga; Brevis, Pedro; Abaca, Paulina; Hubert, Elizabeth

    2002-01-01

    The bacteriocin PsVP-10 is a 2.6 Kda peptide which was isolated and purified from Pseudomonas sp. This bacteriocin possesses lethal activity over Enterococcus faecalis, Salmonella typhimurium and Shigella flexneri. The experimental assays showed that the bacteriocin is able to be adsorbed by all cells of these bacterial species and also by their isolated cell walls. It was observed that the resistant mutants and their respective cell walls are unable to adsorb the bacteriocin. Assays performed with spheroplasts obtained from sensitive bacterial species and their resistant mutants show a rapid lethal effect of the bacteriocin PsVP-10. This results indicated furthermore, it is also shown that the optimal pH and temperature for the adsorption were 7.2 and 37 degrees C, respectively. The study carried out with organic solvents like methanol, ethanol, isopropanol and the detergents sodium dodecyl sulfate and triton X-100 showed a moderate inhibition of the bacteriocin lethal action for the Gram negative cells. The enzymes lysozime, protease XIV and trypsine type III-S did not present any effect over the adsorption capacity of the bacteriocin with any of the bacterial species studied.

  9. 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

  10. Production of two bacteriocins in various growth conditions produced by gram-positive bacteria isolated from chicken cecum.

    Science.gov (United States)

    Wang, Qiuju; Cui, Yizhe; Wang, Wenmei; Xu, Jili; Xu, Li

    2012-01-01

    Lactobacillus plantarum CLP29 and Enterococcus faecium CLE34 isolated from the cecal contents of young broiler chicks were identified based on physiological and biochemical characteristics, and identification was confirmed by 16S rRNA sequencing. Both bacteria showed a broad range of inhibitory action against bacteria such as Salmonella and Escherichia coli and produced two peptides, plantaricin CLP29 and enterocin CLE34. Treatment with proteinase K, trypase, or benase resulted in the loss of activity of the two peptides, confirming their proteinaceous nature. The highest activity levels for both bacteria were recorded in de Man - Rogosa - Sharpe agar at pH 5.0, 6.0, and 7.0, at 37 °C. Carbon and nitrogen sources affected the antibacterial activities of the two bacteriocins in different combinations, which suggested that the antibacterial abilities of different bacteriocins produced in nutrient sources were various.

  11. Partial Characterization of an Anti-Candida albicans Bacteriocin Produced by a Marine Strain of Bacillus sp., Sh10

    OpenAIRE

    Fatemeh Shayesteh; Asmat Ahmad; Gires Usup

    2015-01-01

    The bacteriocin-producing strain Bacillus sp., Sh10, isolated from the marine environment, exhibited a broad spectrum of antimicrobial activity against different food spoilage and human pathogens, with a maximum inhibitory activity against Candida albicans. The inhibitory compound was sensitive to trypsin but resistant to proteinase K, lysozyme, lipase and &alpha-amylase. It was heat-stable and remained its activity after autoclaving. In addition, the antimicrobial substance demonstrated stri...

  12. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  15. The Continuing Story of Class IIa Bacteriocins

    OpenAIRE

    Drider, Djamel; Fimland, Gunnar; Héchard, Yann; McMullen, Lynn M.; Prévost, Hervé

    2006-01-01

    Many bacteria produce antimicrobial peptides, which are also referred to as peptide bacteriocins. The class IIa bacteriocins, often designated pediocin-like bacteriocins, constitute the most dominant group of antimicrobial peptides produced by lactic acid bacteria. The bacteriocins that belong to this class are structurally related and kill target cells by membrane permeabilization. Despite their structural similarity, class IIa bacteriocins display different target cell specificities. In the...

  16. Isolation of bacteriocin - producing lactic acid bacteria from 'Ugba' and 'Okpiye', two locally fermented nigerian food condiments

    Directory of Open Access Journals (Sweden)

    Charles Ogugua Nwuche

    2013-02-01

    Full Text Available In this work, 100 samples each of 'ugba' and 'okpiye' were evaluated for the presence of bacteriocin producing lactic acid bacteria. Thirty strains showing antibacterial activity against at least one of the indicator organisms were selected from a total of 752 colonies isolated from the condiments. Out of the 30, only five strains retained activity after the pH of the broth supernatant was adjusted to 6.5. When evaluated by the agar-well diffusion assay, the spectra of inhibitory activity showed that Staphylococcus aureus was the most sensitive indicator organism tested, while Listeria monocytogenes was the most resistant. One strain (UG 2 was active against Escherichia coli. The assays using the cell-free supernatant of the cultures showed that the bacteriocins were completely inactivated by the proteolyses as well as by the chloroform treatment. In ethanol, the activity of the compounds was only partially modified. When incubated in a water bath at 80°C for 30 min, no significant activity loss was recorded. The antimicrobial activity of the bacteriocins produced by the lactic acid bacteria has potential for use in biopreservation of condiments against the spoilage and food - borne pathogens.

  17. 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.

  18. Purification and Characterization of Bacteriocin Produced by Weissella confusa A3 of Dairy Origin.

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    Hweh Fen Goh

    Full Text Available A dramatic increase in bacterial resistance towards currently available antibiotics has raised worldwide concerns for public health. Therefore, antimicrobial peptides (AMPs have emerged as a promisingly new group of therapeutic agents for managing infectious diseases. The present investigation focusses on the isolation and purification of a novel bacteriocin from an indigenous sample of cow milk and it's mode of action. The bacteriocin was isolated from Weissella confusa A3 that was isolated from the sample and was shown to have inhibitory activity towards pathogenic bacteria namely Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa and Micrococcus luteus. The bacteriocin was shown to be heat stable and functioned well at low pH (2 to 6. Reduction of activity was shown after treatment with proteinase K, trypsin and peptidase that confirmed the proteinaceous nature of the compound. MALDI-TOF analysis of the sample gave a mass approximating 2.7 kDa. The membrane of the bacteria was disrupted by the bacteriocin causing SYTOX® green dye to enter the cell and bind to the bacterial DNA giving fluorescence signal. Bacterial cell treated with the bacteriocin also showed significant morphological changes under transmission electron microscope. No virulence and disease related genes can be detected from the genome of the strain.

  19. Purification and Characterization of Bacteriocin Produced by Weissella confusa A3 of Dairy Origin

    Science.gov (United States)

    Goh, Hweh Fen; Philip, Koshy

    2015-01-01

    A dramatic increase in bacterial resistance towards currently available antibiotics has raised worldwide concerns for public health. Therefore, antimicrobial peptides (AMPs) have emerged as a promisingly new group of therapeutic agents for managing infectious diseases. The present investigation focusses on the isolation and purification of a novel bacteriocin from an indigenous sample of cow milk and it’s mode of action. The bacteriocin was isolated from Weissella confusa A3 that was isolated from the sample and was shown to have inhibitory activity towards pathogenic bacteria namely Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa and Micrococcus luteus. The bacteriocin was shown to be heat stable and functioned well at low pH (2 to 6). Reduction of activity was shown after treatment with proteinase K, trypsin and peptidase that confirmed the proteinaceous nature of the compound. MALDI-TOF analysis of the sample gave a mass approximating 2.7 kDa. The membrane of the bacteria was disrupted by the bacteriocin causing SYTOX® green dye to enter the cell and bind to the bacterial DNA giving fluorescence signal. Bacterial cell treated with the bacteriocin also showed significant morphological changes under transmission electron microscope. No virulence and disease related genes can be detected from the genome of the strain. PMID:26474074

  20. Screening of Bacteriocin-producing Lactic Acid Bacteria%产细菌素乳酸菌的筛选

    Institute of Scientific and Technical Information of China (English)

    胡欣洁; 刘云; 邓清云

    2012-01-01

    [Objective]To develop a strain of high-efficient bacteriocin with broader antimicrobial spectrum as natural preservative. [ Method] With pickles and yoghurt as raw materials, the bacteria, which could inhibit the indicator bacteria, was screened from the test materials by using MRS selective medium, and whether the bacteria could produce bacteriocin or not was determined by the tests of excluding acid inhibition, hydrogen peroxide inhibition and protease sensitivity. [Result]The screened strain was identified to be lactic acid bacteria, the produced bacteriocin had inhibitive effect against gram-negative and gram-positive bacteria, and it was a strain of lactic acid bacteria with iroad spectrum and the ability of bacteriocin-producing. [Conclusion]The bacteriocin-producing lactic acid bacteria had important roles in inhibiting various pathogens and food decay.%[目的]开发出更加高效、抑菌谱更广、可做天然防腐剂的细菌素.[方法]以泡菜、酸奶为原料,利用MRS选择培养基从试材中筛选出能够抑制指示菌的细菌,通过排除酸抑制作用、过氧化氢抑制作用和蛋白酶敏感性试验证明该菌株是否产生有抑菌作用的细菌素.[结果]筛选得到的菌株经鉴定证明是乳酸菌,其产生的细菌素对革兰氏阴性菌和革兰氏阳性菌都有抑制作用,是一株产广谱细菌素的乳酸菌.[结论]筛选得出的乳酸菌细菌素在抑制各种病原菌和食品腐败等方面具有重要作用.

  1. Purification and Characterization of Bacteriocin Produced by Lactobacillus brevis UN Isolated from Dhulliachar: a Traditional Food Product of North East India.

    Science.gov (United States)

    Gautam, Neha; Sharma, Nivedita; Ahlawat, O P

    2014-06-01

    A bacteriocin producing strain Lactobacillus brevis UN isolated from Dulliachar-a salted pickle and identified by biochemical and molecular methods. L. brevis UN was found to produce bacteriocin with broad spectrum activity against spoilage causing/food borne pathogens viz. L. monocytogenes, C. perfringens, S. aureus, L. mesenteroides, L. plantarum and B. cereus. Bacteriocin production was optimized through classical one variable at a time method. The isolate showed maximum bacteriocin production at early stationary phase, pH 4.0, temperature 35 °C and with an inoculum size of 1.5 OD @ 10 %. Bacteriocin produced by L. brevis UN was purified to homogeneity by single step gel exclusion chromatography and was most active at pH 6.0 and 7.0, stable up to 100 °C and was proteinaceous in nature. The results of NMR revealed the presence of proline, glutamic acid, aspartic acid, leucine, isoleucine and serine in its peptide structure. PCR amplification analysis determined that bacteriocin encoded gene in L. brevis UN was plasmid bound.

  2. Purification and characterization of bacteriocin produced by strain of Lactobacillus brevis MTCC 7539.

    Science.gov (United States)

    Gautam, Neha; Sharma, Nivedita

    2009-08-01

    Bacteriocin, an antimicrobial agent having potential for food biopreservation was purified from Lactobacillus brevis (a safe food-grade bacteria isolated from Vari Kandal, a traditional fermented food of Himachal Pradesh by adopting a novel repeated washing method. Its purity was confirmed by SDS-PAGE and Native-PAGE. The relative molecular mass of bacteriocin was 93.74 kD, while specific activity and recovery were 35.52 folds and 17.13%, respectively. It showed high thermal stability and was active over wide range of pH and exhibited sensitivity to trypsin.

  3. Bacteriocins: safe, natural antimicrobials for food preservation.

    Science.gov (United States)

    Cleveland, J; Montville, T J; Nes, I F; Chikindas, M L

    2001-12-01

    Bacteriocins are antibacterial proteins produced by bacteria that kill or inhibit the growth of other bacteria. Many lactic acid bacteria (LAB) produce a high diversity of different bacteriocins. Though these bacteriocins are produced by LAB found in numerous fermented and non-fermented foods, nisin is currently the only bacteriocin widely used as a food preservative. Many bacteriocins have been characterized biochemically and genetically, and though there is a basic understanding of their structure-function, biosynthesis, and mode of action, many aspects of these compounds are still unknown. This article gives an overview of bacteriocin applications, and differentiates bacteriocins from antibiotics. A comparison of the synthesis. mode of action, resistance and safety of the two types of molecules is covered. Toxicity data exist for only a few bacteriocins, but research and their long-time intentional use strongly suggest that bacteriocins can be safely used.

  4. Behaviour and Biological Control of Bacteriocin-Producing Leuconostocs Associated with Spoilage of Vacuum-Packaged Sucuk

    OpenAIRE

    OSMANAĞAOĞLU, Özlem

    2014-01-01

    Non-motile, Gram-positive and catalase-negative anaerobic Leuconostoc sp. were found to be involved in the spoilage of vacuum-packaged refrigerated sucuk samples. The spoilage was associated with an accumulation of large quantities of foul-smelling gas and purge in the bag and loss of colour and texture in the meat. Many of these isolates produce bacteriocins, to which the predominant Gram-positive bacteria normally found in these products are sensitive. As the leuconostocs grew at low temper...

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

    Directory of Open Access Journals (Sweden)

    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.

  6. Plantaricins S and T, Two New Bacteriocins Produced by Lactobacillus plantarum LPCO10 Isolated from a Green Olive Fermentation

    Science.gov (United States)

    Jiménez-Díaz, R.; Rios-Sánchez, R. M.; Desmazeaud, M.; Ruiz-Barba, J. L.; Piard, J.-C.

    1993-01-01

    Twenty-six strains of Lactobacillus plantarum isolated from green olive fermentations were tested for cross-antagonistic activities in an agar drop diffusion test. Cell-free supernatants from four of these strains were shown to inhibit the growth of at least one of the L. plantarum indicator strains. L. plantarum LPCO10 provided the broadest spectrum of activity and was selected for further studies. The inhibitory compound from this strain was active against some gram-positive bacteria, including clostridia and propionibacteria as well as natural competitors of L. plantarum in olive fermentation brines. In contrast, no activity against gram-negative bacteria was detected. Inhibition due to the effect of organic acids, hydrogen peroxide, or bacteriophages was excluded. Since the inhibitory activity of the active supernatant was lost after treatment with various proteolytic enzymes, this substance could be classified as a bacteriocin, designated plantaricin S. Plantaricin S was also sensitive to glycolytic and lipolytic enzymes, suggesting that it was a glycolipoprotein. It exhibited a bactericidal and nonbacteriolytic mode of action against indicator cells. This bacteriocin was heat stable (60 min at 100°C), active in a pH range of 3.0 to 7.0, and also stable in crude culture supernatants during storage. Ultrafiltration studies indicated that plantaricin S occurred as multimolecular aggregates and that the size of the smallest active form is between 3 and 10 kDa. In sodium dodecyl sulfate-polyacrylamide gels, plantaricin S migrated as a peptide of ca. 2.5 kDa. Maximum production of plantaricin S was obtained in a fermentor system in unregulated pH and log-phase cultures of L. plantarum LPCO10 in MRS broth plus 4% NaCl. In these culture conditions, a second bacteriocin (designated plantaricin T) was produced in late-stationary-phase cultures of L. plantarum LPCO10. On the basis of its biological activity, its sensitivity to various enzymes, and its molecular weight

  7. 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.

  8. Isolation and characterization of a nisin-like bacteriocin produced by a Lactococcus lactis strain isolated from charqui, a Brazilian fermented, salted and dried meat product.

    Science.gov (United States)

    Biscola, V; Todorov, S D; Capuano, V S C; Abriouel, H; Gálvez, A; Franco, B D G M

    2013-03-01

    A Lactococcus lactis subsp. lactis strain (L. lactis 69) capable to produce a heat-stable bacteriocin was isolated from charqui, a Brazilian fermented, salted and sun-dried meat product. The bacteriocin inhibited, in vitro, Listeria monocytogenes, Staphylococcus aureus, several lactic acid bacteria isolated from foods and spoilage halotolerant bacteria isolated from charqui. The activity of the bacteriocin was not affected by pH (2.0-10.0), heating (100 °C), and chemical agents (1% w/v). Treatment of growing cells of L. monocytogenes ScottA with the cell-free supernatant of L. lactis 69 resulted in complete cell inactivation. L. lactis 69 harbored the gene for the production of a nisin-like bacteriocin, and the amino acid sequence of the active peptide was identical to sequences previously described for nisin Z. However, differences were observed regarding the leader peptide. Besides, the isolate was able to survive and produce bacteriocins in culture medium with NaCl content up to 20%, evidencing a potential application as an additional hurdle in the preservation of charqui. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Lactococcal bacteriocins : mode of action and immunity

    NARCIS (Netherlands)

    Venema, Koen; Venema, Gerard; Kok, Jan

    1995-01-01

    Bacteriocins are antimicrobial peptides produced by bacteria. Some of those synthesized by Lactococcus lactis have been characterized in great detail recently. The lactococcal bacteriocins are hydrophobic cationic peptides, which form pores in the cytoplasmic membrane of sensitive cells.

  10. LACTOCOCCAL BACTERIOCINS - MODE OF ACTION AND IMMUNITY

    NARCIS (Netherlands)

    VENEMA, K; KOK, J; Venema, Gerhardus

    1995-01-01

    Bacteriocins are antimicrobial peptides produced by bacteria. Some of those synthesized by Lactococcus lactis have been characterized in great detail recently. The lactococcal bacteriocins are hydrophobic cationic peptides, which form pores in the cytoplasmic membrane of sensitive cells.

  11. Lacticin LC14, a new bacteriocin produced by Lactococcus lactis BMG6.14: isolation, purification and partial characterization.

    Science.gov (United States)

    Lasta, Samar; Ouzari, Hadda; Andreotti, Nicolas; Fajloun, Ziad; Mansuelle, Pascal; Boudabous, Abdellatif; Sampieri, Francois; Sabatier, Jean Marc

    2012-08-01

    A new bacteriocin, lacticin LC14, produced by Lactococcus lactis BMG6.14, was isolated and characterized. It was purified to homogeneity from overnight broth culture by ammonium sulfate precipitation, Sep-Pak chromatography, and two steps of reversed-phase HPLC. Lacticin LC14 showed bactericidal-type antimicrobial activity against several lactic acid bacteria and pathogenic strains including Listeria monocytogenes. It was inactivated by proteinase K and pronase E, but was resistant to papain, lysozyme, lipase and catalase. Lacticin LC14 was heat resistant, stable over a wide range of pH (2-10) and after treatment by solvents and detergents. Its N-terminal end was found unreactive towards Edman sequencing. Based on MALDI-TOF mass spectrometry, its molecular mass was 3333.7 Da. LC14 amino acid composition revealed a high proportion of hydrophobic residues, but no modified ones. LC14 may be able to challenge other well known other bacteriocins in probiotic and therapeutic applications.

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

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    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.

  13. 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 ana

  14. 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 ana

  15. Use of bacteriocin-producing, probiotic strain Enterococcus faecium AL41 to control intestinal microbiota in farm ostriches.

    Science.gov (United States)

    Lauková, A; Kandričáková, A; Ščerbová, J

    2015-06-01

    Probiotic enterococci can produce bacteriocins. Enterococcus faecium AL41 is an Enterocin M-producing, probiotic strain which has previously shown beneficial effect in broiler chickens. In this study, it was used to control intestinal microbiota in farm ostriches in a 42-day experiment with an experimental group (EG, 40 ostriches) and a control group (CG, 46). In addition to feed mixture, the ostriches in EG received Ent. faecium AL41 (10(9) CFU ml(-1); by rifampicin-marked variant) 400 μl per animal per day in their drinking water for 21 days. Sampling was carried out at the start of the experiment (at day 0/1), at day 21 (after 21 days of AL41 application) and at day 42 (21 days after AL41 cessation). Faeces (mixture, n = 6) were treated using the standard microbiological dilution method and cultivated on selective media (ISO). The highest count of AL41 was found at day 42. Its identity was confirmed with PCR and Maldi-Tof. The ostriches were free of Salmonella and Campylobacter cells. At day 21, antimicrobial effect was demonstrated by significant reduction in coagulase-positive and negative staphylococci in EG compared to CG (P intestinal microbiota in farm ostriches. Significance and impact of the study: Ostriches are excellent for high intensity farming in a wide range of climates, requiring only limited space and giving high yields per hectare. They are reared mainly for their meat. Although adult birds possess quite good immunity, young birds can be threatened by spoilage bacteria, especially when they are transferred from the nests to the farm area. Based on our previous results related to the beneficial effect of bacteriocin-producing, probiotic strain Enterococcus faecium AL41 in poultry or rabbits, we decided to test its ability to control intestinal microbiota in farming ostriches which has never been tested previously.

  16. 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.

  17. 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.

  18. 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.

  19. Effects of gassericins A and T, bacteriocins produced by Lactobacillus gasseri, with glycine on custard cream preservation.

    Science.gov (United States)

    Arakawa, K; Kawai, Y; Iioka, H; Tanioka, M; Nishimura, J; Kitazawa, H; Tsurumi, K; Saito, T

    2009-06-01

    Lactobacillus gasseri LA39 and LA158 isolated from human-infant feces produce bacteriocins named gassericins A and T, respectively. Both gassericins have high heat stability (121 degrees C, 10 min), good pH tolerance (pH 2-11), and strong bactericidality against many gram-positive bacteria, especially lactic acid bacteria, and thus are expected to be effective food preservatives. A microwell plate assay against 12 strains of custard cream spoilage bacteria showed that the gassericins had broader antibacterial spectra than nisin A. Although the gassericins allowed gram-negative isolates to grow, they successfully inhibited the growth of all tested bacterial strains in microwells with the addition of glycine. Glycine was bacteriostatic against many strains except lactic acid bacteria. For practical use, gassericin A was efficiently produced by cultivation in a food-grade medium improved using cheese whey, nourishing proteose peptone, and surfactant yolk lecithin. The practical preservative effect of gassericin A and glycine was verified from the viability of 4 isolated strains, Bacillus cereus, Lactococcus lactis ssp. lactis, Achromobacter denitrificans, and Pseudomonas fluorescens, in custard creams. Custard cream containing 123 arbitrary units of gassericin A per milliliter entirely growth-inhibited the 2 gram-positive strains. In custard cream containing an insufficient amount of gassericin A (49 arbitrary units/mL), the gram-positive strains gradually grew but were completely inhibited by the addition of 0.5% (wt/wt) glycine. The 2 gram-negative strains did not multiply even in the additive-free custard cream, probably because of the unsuitable growth environment. This is the first report showing the combined effect of bacteriocin and glycine and their application for food preservation, which may be helpful for future use in the food industry.

  20. AS-48 bacteriocin : close to perfection

    NARCIS (Netherlands)

    Sánchez-Hidalgo, Marina; Montalbán-López, Manuel; Cebrián, Rubén; Valdivia, Eva; Martínez-Bueno, Manuel; Maqueda, Mercedes

    2011-01-01

    Bacteriocin AS-48 is an intriguing molecule because of its unique structural characteristics, genetic regulation, broad activity spectrum, and potential biotechnological applications. It was the first reported circular bacteriocin and has been undoubtedly the best characterized for the last 25 years

  1. Characterization of the genetic locus responsible for the production of ABP-118, a novel bacteriocin produced by the probiotic bacterium Lactobacillus salivarius subsp. salivarius UCC118.

    Science.gov (United States)

    Flynn, Sarah; van Sinderen, Douwe; Thornton, Gerardine M; Holo, Helge; Nes, Ingolf F; Collins, J Kevin

    2002-04-01

    ABP-118, a small heat-stable bacteriocin produced by Lactobacillus salivarius subsp. salivarius UCC118, a strain isolated from the ileal-caecal region of the human gastrointestinal tract, was purified to homogeneity. Using reverse genetics, a DNA fragment specifying part of ABP-118 was identified on a 10769 bp chromosomal region. Analysis of this region revealed that ABP-118 was a Class IIb two-peptide bacteriocin composed of Abp118alpha, which exhibited the antimicrobial activity, and Abp118beta, which enhanced the antimicrobial activity. The gene conferring strain UCC118 immunity to the action of ABP-118, abpIM, was identified downstream of the abp118beta gene. Located further downstream of abp118beta, several ORFs were identified whose deduced proteins resembled those of proteins involved in bacteriocin regulation and secretion. Heterologous expression of ABP-118 was achieved in Lactobacillus plantarum, Lactococcus lactis and Bacillus cereus. In addition, the abp118 locus encoded an inducing peptide, AbpIP, which was shown to play a role in the regulation of ABP-118 production. This novel bacteriocin is, to the authors' knowledge, the first to be isolated from a known human probiotic bacterium and to be characterized at the genetic level.

  2. The bacteriocins produced by Lactobacillus plantarum%植物乳杆菌细菌素的研究与应用

    Institute of Scientific and Technical Information of China (English)

    陈一然; 张明

    2011-01-01

    Because of the variety of bacteriocins from Lactobacillus plantarum and beneficial effects produced during ferment, it became popular to do research on bacteriocins from L plantarum. In this paper, with the purpose to provide a reference for further studies of bacteriocins from L plantarum, the characteristics were introduced elaborately, including types, molecule structures, inhibition mechanisms and inheritance control. Also, the applications of bacteriocins from L plantarum in food preservatives, medicine industry, and agriculture were simply summed up.%植物乳杆菌细菌素不仅种类多,产生菌在发酵过程中还可产生良好的保健功效,因此成为研究的热点.本文对植物乳杆菌细菌素的种类、分子结构、抑菌机制及遗传控制做了较为详尽的介绍,并简要介绍了植物乳杆菌细菌素在食品、医药、饲料中的应用,为进一步研究植物乳杆菌细菌素提供了参考.

  3. PRESERVATIVE POTENTIAL OF PURIFIED BACTERIOCIN PRODUCED FROM BREVIBACILLUS BORSTELENSIS AG1 ISOLATED FROM MARCHA – A TRADITIONAL WINE STARTER CULTURE CAKE IN TOMATO PASTE

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    Anupama Gupta

    2015-04-01

    Full Text Available Purified bacteriocin produced from Brevibacillus borstelensis AG1 isolated from Marcha a local wine starter herbal cake, was used to enhance the shelf life of tomato paste. Preservative effect of purified bacteriocin was studied for nine days in tomato paste inoculated with food borne pathogens and was compared to commercial biopreservative – nisin and chemical preservative – sodium benzoate. The indicator strains i.e. Listeria monocytogenes MTCC839, Bacillus subtilis CRI and Clostridium perfringens MTCC1739 were used at the amount 8.16, 8.13 and 8.18 log CFU/ml. Viable cells were counted periodically and a consistent reduction in number of viable cells of each tested pathogen was observed. It was found antagonistic against L. monocytogenes MTCC839, B. subtilis CRI and C. perfringes MTCC1739 which are the most challengeable and food borne pathogens found in processed vegetables products. Purified bacteriocin was found active over a wide pH range i.e. 3.0 to 11.0 and was able to withstand temperature up to 100oC. It showed a better preservative potential by reducing pathogenic load of the tested strains (by 2.02, 2.05 and 2.02 log cycles (CFU/ml of L. monocytogenes MTCC839, B. subtilis CRI and C. perfringes MTCC1739, respectively in tomato paste as compared to control (without bacteriocin. This proves efficiency of bacteriocin produced by B. borstelensis AG1 as biopreservative to enhance the safety and shelf life of acidic foods.

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

    Science.gov (United States)

    Oliveira, Letícia de C; Silveira, Aline M M; Monteiro, Andréa de S; Dos Santos, Vera L; Nicoli, Jacques R; Azevedo, Vasco A de C; Soares, Siomar de C; Dias-Souza, Marcus V; Nardi, Regina M D

    2017-01-01

    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.

  5. 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.

  6. Purification and Characterization of Plantaricin JLA-9: A Novel Bacteriocin against Bacillus spp. Produced by Lactobacillus plantarum JLA-9 from Suan-Tsai, a Traditional Chinese Fermented Cabbage.

    Science.gov (United States)

    Zhao, Shengming; Han, Jinzhi; Bie, Xiaomei; Lu, Zhaoxin; Zhang, Chong; Lv, Fengxia

    2016-04-06

    Bacteriocins are ribosomally synthesized peptides with antimicrobial activity produced by numerous bacteria. A novel bacteriocin-producing strain, Lactobacillus plantarum JLA-9, isolated from Suan-Tsai, a traditional Chinese fermented cabbage, was screened and identified by its physiobiochemical characteristics and 16S rDNA sequence analysis. A new bacteriocin, designated plantaricin JLA-9, was purified using butanol extraction, gel filtration, and reverse-phase high-performance liquid chromatography. The molecular mass of plantaricin JLA-9 was shown to be 1044 Da by MALDI-TOF-MS analyses. The amino acid sequence of plantaricin JLA-9 was predicted to be FWQKMSFA by MALDI-TOF-MS/MS, which was confirmed by Edman degradation. This bacteriocin exhibited broad-spectrum antibacterial activity against Gram-positive and Gram-negative bacteria, especially Bacillus spp., high thermal stability (20 min, 121 °C), and narrow pH stability (pH 2.0-7.0). It was sensitive to α-chymotrypsin, pepsin, alkaline protease, and papain. The mode of action of this bacteriocin responsible for outgrowth inhibition of Bacillus cereus spores was studied. Plantaricin JLA-9 had no detectable effects on germination initiation over 1 h on monitoring the hydration, heat resistance, and 2,6-pyridinedicarboxylic acid (DPA) release of spores. Rather, germination initiation is a prerequisite for the action of plantaricin JLA-9. Plantaricin JLA-9 inhibited growth by preventing the establishment of oxidative metabolism and disrupting membrane integrity in germinating spores within 2 h. The results suggest that plantaricin JLA-9 has potential applications in the control of Bacillus spp. in the food industry.

  7. Genetic analysis of a unique bacteriocin, Smb, produced by Streptococcus mutans GS5.

    Science.gov (United States)

    Yonezawa, Hideo; Kuramitsu, Howard K

    2005-02-01

    A dipeptide lantibiotic, named Smb, in Streptococcus mutans GS5 was characterized by molecular genetic approaches. The Smb biosynthesis gene locus is encoded by a 9.5-kb region of chromosomal DNA and consists of seven genes in the order smbM1, -T, -F, -M2, -G, -A, -B. This operon is not present in some other strains of S. mutans, including strain UA159. The genes encoding Smb were identified as smbA and smbB. Inactivation of smbM1, smbA, or smbB attenuated the inhibition of the growth of the indicator strain RP66, confirming an essential role for these genes in Smb expression. Mature Smb likely consists of the 30-amino-acid SmbA together with the 32-amino-acid SmbB. SmbA exhibited similarity with the mature lantibiotic lacticinA2 from Lactococcus lactis, while SmbB was similar to the mersacidin-like peptides from Bacillus halodurans and L. lactis. We also demonstrated that Smb expression is induced by the competence-stimulating peptide (CSP) and that a com box-like sequence is located in the smb promoter region. These results suggest that Smb belongs to the class I bacteriocin family, and its expression is dependent on CSP-induced quorum sensing.

  8. 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.

  9. Prevention of streptococcal pharyngitis by anti-Streptococcus pyogenes bacteriocin-like inhibitory substances (BLIS) produced by Streptococcus salivarius.

    Science.gov (United States)

    Tagg, J R

    2004-05-01

    Streptococcus salivarius is a numerically prominent member of the human oral microbiota that produces a variety of bacteriocin-like inhibitory substances (BLIS) having in vitro inhibitory activity against S. pyogenes. Our previous studies of S. salivarius isolates from children using a deferred antagonism BLIS production (P)-typing scheme showed that the 9 per cent of children having large populations of P-type 677 S. salivarius experienced fewer S. pyogenes acquisitions than either the 11 per cent of children having predominant P-type 226 populations or the 60 per cent of children with largely non-inhibitory (P-type 000) S. salivarius. Amongst the other BLIS P-types detected were a number of strongly-inhibitory (P-type 777) S. salivarius. In the present study the inhibitory agents produced by prototype strains of P-types 226, 677 and 777 S. salivarius are compared. The prototype BLIS-producing S. salivarius strains SN, 20P3, and K12 were isolated from tongue swabbings. BLIS P-typing was done using standard procedures. The BLIS molecules were purified and characterized. S. salivarius SN (P-type 226) produces a heat-labile muramidase. S. salivarius 20P3 (P-type 677) produces the 2315 Da lantibiotic salivaricin A and S. salivarius K12 (P-type 777) produces two lantibiotics; salivaricin A2 (2368 Da) and salivaricin B (2733 Da). The P-type 777 S. salivarius strain produced salivaricin A2 and salivaricin B. The combined production of two anti-S. pyogenes BLIS activities by this strain indicates that it could be adopted as a colonizing strain in bacterial interference trials.

  10. 产细菌素弯曲乳杆菌的分离鉴定及细菌素特性初步研究%Separation and identification of bacteriocin-producing Lactobacillus curvatus and characterization of its bacteriocin

    Institute of Scientific and Technical Information of China (English)

    任丽; 刘国荣; 王成涛; 孙宝国

    2013-01-01

    Bacteriocin-producing stain RX-6 was isolated from Spanish traditional Salami sausages. After eliminating some interference factors such as the organic acids,hydrogen peroxides and strain cells,the antimicrobial activity of the fermentation broth of strain RX-6 remained the same. By ammonium sulphate precipitation and dialysis,the activity was significantly enhanced. However,the substance was inactivated when treated with proteinase K. These results indicated the nature of antibacterial substance produced by strain RX-6 was protein. Based on morphological,physiological and biochemical characteristics, 16S rRNA gene sequence and phylogenic analysis, strain RX-6 was identified as Lactobacillus curvatus. Results obtained from characteristics analysis of the bacteriocin produced by strain RX-6 showed this bacteriocin still remained activated after the heat treatment at 121℃ for 20min and the pH activity range was 3 to 10, which indicated that it had strong heat stability and acid-base tolerance. Also, the bacteriocin could be inactivated by pepsin and trypsin.and partially inactivated by acid proteinase,which suggested that its use safety was very high. In addition,the bacteriocin had a broad inhibitory spectrum and could show inhibitory activity against Listeria spp., Staphylococcus spp., Pseudomonas spp. and Escherichia coli, which indicated that the bacteriocin had a potential application as natural food bio-preservatives in food industry.%从西班牙传统色拉米香肠中分离到一株产细菌素菌株RX-6,其发酵液在排除有机酸、过氧化氢及菌体细胞干扰后,抑菌活性基本无变化;经硫酸铵盐析及透析处理后,抑菌活性明显增强;蛋白酶K处理后,抑菌活性消失,表明起抑菌作用的是蛋白类物质.通过菌体形态观察、生理生化特征实验、16S rRNA序列比对及系统发育分析,鉴定菌株RX-6为弯曲乳杆菌(Lactobacillus curvatus).抑菌特性研究结果显示该菌株所产细菌素具

  11. Isolation and Taxonomic Identity of Bacteriocin-Producing Lactic Acid Bacteria from Retail Foods and Animal Sources.

    Science.gov (United States)

    Henning, Chris; Vijayakumar, Paul; Adhikari, Raj; Jagannathan, Badrinath; Gautam, Dhiraj; Muriana, Peter M

    2015-03-19

    Bacteriocin-producing (Bac⁺) lactic acid bacteria (LAB) were isolated from a variety of food products and animal sources. Samples were enriched in de Man, Rogosa, and Sharpe (MRS) Lactocilli broth and plated onto MRS agar plates using a "sandwich overlay" technique. Inhibitory activity was detected by the "deferred antagonism" indicator overlay method using Listeria monocytogenes as the primary indicator organism. Antimicrobial activity against L. monocytogenes was detected by 41 isolates obtained from 23 of 170 food samples (14%) and 11 of 110 samples from animal sources (10%) tested. Isolated Bac⁺ LAB included Lactococcus lactis, Lactobacillus curvatus, Carnobacterium maltaromaticum, Leuconostoc mesenteroides, and Pediococcus acidilactici, as well as Enterococcus faecium, Enterococcus faecalis, Enterococcus hirae, and Enterococcus thailandicus. In addition to these, two Gram-negative bacteria were isolated (Serratia plymuthica, and Serratia ficaria) that demonstrated inhibitory activity against L. monocytogenes, Staphylococcus aureus, and Enterococcus faecalis (S. ficaria additionally showed activity against Salmonella Typhimurium). These data continue to demonstrate that despite more than a decade of antimicrobial interventions on meats and produce, a wide variety of food products still contain Bac⁺ microbiota that are likely eaten by consumers and may have application as natural food preservatives.

  12. Detectionn and activity of plantaricin OL15 a bacteriocin produced by Lactobacillus plantarum OL15 isolated from Algerian fermented olives.

    Directory of Open Access Journals (Sweden)

    Nour-Eddine, Karam

    2005-09-01

    Full Text Available Lactobacillus plantarum OL15 previously isolated from Algerian fermented green olives produces antimicrobial conpounds in its culture medium. Inhibitory action against other strains of Lactobacillus, Lactococcus , and Propionibacterium was observed . Activity was completely or partially inactivated by proteolytic enzymes, stable at pH values ranging from 3.0 to 8.0, and heat stable even after autoclaving at 121 °C for 15 min. The bacteriocin activity was able to pass through cellulose membranes with 100,000 but not through 10,000 molecular weight cut-off.Lactobacillus plantarum OL15, aislado de aceitunas verdes argelinas, produce un compuesto antimicrobiano en el medio de cultivo, observándose un efecto inhibidor frente a otras cepas de Lactobacillus, Lactococcus y Propionibacterium . Dicha actividad desaparece completa o parcialmente después del tratamiento con enzimas proteolíticas, es estable al pH en el rango de 3,0 a 8,0 y es, asimismo estable al calor incluso después de someterla a un proceso térmico de 121 ºC durante 15 minutos. La bacteriocina pasa a través de membranas de celulosa de corte molecular de 1000.000 pero no a través de las de 10.000.

  13. Characterization of bacteriocins produced by Lactococcus lactis strains Caracterização de bacteriocinas produzidas por linhagens de Lactococcus lactis

    Directory of Open Access Journals (Sweden)

    Izildinha Moreno

    2000-09-01

    Full Text Available Bacteriocins produced by fifteen strains of Lactococcus lactis (14 L. lactis subsp. lactis and one L. lactis subsp. cremoris were heat resistant, sensitive to several proteolytic enzymes and active over a wide range of pH. Their resistance to the heating was greatly influenced by the pH. Only the strain L. lactis subsp. lactis ITAL 383 produced a bacteriocin with a wide activity spectrum, similar to nisin of L. lactis subsp. lactis ATCC 11454. This bacteriocin inhibited closely related species and other Gram-positive microorganisms including Listeria monocytogenes and Staphylococcus aureus, but it was not active against the Gram-negative bacteria tested. The identification of partially purified antimicrobial compounds by SDS-PAGE showed that bacteriocin produced by strain ITAL 383 had the same molecular weight of nisin produced by L. lactis subsp. lactis ATCC 11454.Bacteriocinas resistentes ao aquecimento produzidas por quinze linhagens de Lactococcus lactis (14 L. lactis subsp. lactis e 1 L. lactis subsp. cremoris foram sensíveis à enzimas proteolíticas e ativas em uma ampla faixa de pH. A resistência dessas bacteriocinas ao aquecimento foi fortemente influenciada pelo pH do meio. Somente a linhagem L. lactis subsp. lactis ITAL 383 produziu uma bacteriocina com um amplo espectro de atividade, semelhante ao da nisina de L. lactis subsp. lactis ATCC 11454. Esta bacteriocina inibiu as espécies relacionadas e outros microorganismos gram-positivos, inclusive Listeria monocytogenes e Staphylococcus aureus, mas não as bactérias Gram-negativas examinadas. A identificação do composto antimicrobiano parcialmente purificado por SDS-PAGE revelou um peso molecular similar entre a bacteriocina ITAL 383 e a nisina de L. lactis subsp lactis ATCC 11454.

  14. 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.

  15. Screening of bacteriocin producing lactic acid bacteria and the analysis of bacteriocin related genes%产细菌素乳酸菌的筛选及细菌素相关基因的分析

    Institute of Scientific and Technical Information of China (English)

    张旭; 赵斌; 张香美; 李平兰

    2013-01-01

    In order to obtain a bacteriocin producing strain,lactic acid bacteria were separated and screened with dissolve calcium circle and oxford cup double-plate method from premium fermentation meat.Morphological,physiological biochemistry method,16S rDNA and specific gene PCR amplification were used to identify the strain to species,and the bacteriocin related gene was analyzed to determine bacteriocin types.The results showed that,after eliminating organic acid,hydrogen peroxide and other interference factors,L-ZS9 still had antibacterial activity among the 92 strains and its antibacterial substances were sensitive to protease (acid protease,protease K,trypsin,pepsin,neutral protease),while insensitive to alpha amylase.Therefore,L-ZS9 was recognized as bacteriocin producing bacteria and identified as Lactobacillus paraplantarum.Further bacteriocin related gene PCR amplification showed that L-ZS9 contained Ⅱ b plantaricins EF,JK,Ⅱ c plantaricin A and plantaricin N encoding gene.The mature peptide sequences of plnF,plnK were identical with Lactobacillus plantarum C11 (X94434) and only one amino acid mutation occurred in pinE,plnJ mature peptide sequences.Therefore,the Lactobacillus paraplantarum L-ZS9 was a nature multibacteriocinogenic strain.%试验利用溶钙圈法及牛津杯双层平板法,从国内外优良发酵肉品中分离筛选产细菌素的乳酸菌,通过形态学、生理生化学鉴定,16S rDNA及种间特异性基因PCR扩增将菌株鉴定到种,并对其细菌素相关基因进行分析,初步确定细菌素种类.结果表明:在排除有机酸、过氧化氢等干扰因素后,从分离纯化到的92株乳酸菌中筛选到一株对指示菌仍有明显抑制作用的菌株L-ZS9,该菌株所产抑菌物质对蛋白酶(酸性蛋白酶、蛋白酶K、胰蛋白酶、胃蛋白酶和中性蛋白酶)敏感,而α-淀粉酶对其活性基本无影响,因而确定L-ZS9为细菌素产生菌.经鉴定L-ZS9为类植物乳杆菌,进一步对菌株细菌素

  16. 嗜酸乳杆菌产细菌素的分离纯化研究%SEPARATION AND PURIFICATION OF BACTERIOCINS PRODUCED BY LACTOBACILLUS ACIDOPHILUS

    Institute of Scientific and Technical Information of China (English)

    陈静; 何连芳; 张玉苍

    2011-01-01

    We carried out the separation and purification of bacteriocins produced by Lactobacillus acidophlus and studied the biological characteristics. The results showed that the bacteriocins produced by Lactobacillus acidophlus had thermal stability and better stability in the pH range of 2.0 to 9.0, and still kept the activity after being processed at 120 ℃ for 30 min. The fermented supernant was sensitive to proteases, which showed that the antibacterial substance belonged to proteins; and the fermented supernant had inhibitory effects on Gram-positive bacteria and Gram-negative bacteria. We could prepare the crude bacteriocin extract after ammonium sulfate precipitation and dialysis of the fermented supernant, then purified the crude bacteriocin extract by SephadexG-50 gel chromatography, and determined that the molecular weight of the bacteriocins was about 2 000 by Tricine-SDS-PAGE.%对一株嗜酸乳杆菌所产细菌素进行了分离纯化,并研究了其生物学特性.结果表明,嗜酸乳杆菌产的细菌素具有热稳定性,在120 ℃处理30 min仍保留活性,该细菌素在pH2.0 ~9.0范围内有较好的稳定性.发酵上清液对蛋白酶敏感,表明此抑茼物质为蛋白类物质,对革兰氏阴性菌及革兰氏阳性菌均有抑制作用.发酵上清液经过硫酸铵沉淀、透析后得到细菌素粗提液,然后利用SephadexG-50凝胶层析进行纯化,采用Tricine-SDS-PAGE电泳测其相对分子质量约为2 000.

  17. Are bacteriocins underexploited? : Novel applications for old antimicrobials

    NARCIS (Netherlands)

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

    2011-01-01

    Bacteriocins are ribosomally synthesized (poly)peptides produced by almost all prokaryotic lineages. Bacteriocins from lactic acid bacteria (LAB) and bacteriocin-producer probiotic organisms have been thoroughly studied due to their wide spectra of action, the long-term use in food fermentations and

  18. Mutational analysis and chemical modification of Cys24 of lactococcin B, a bacteriocin produced by Lactococcus lactis

    NARCIS (Netherlands)

    Venema, K; Dost, MHR; Kok, J; Dost, Michiel H.R.; Venema, Gerhardus

    1996-01-01

    Using site-directed mutagenesis the single cysteine residue at position 24 of lactococcin B was replaced by all other possible amino acids. Most of these mutant molecules retained bacteriocin activity, with the exception of those in which cysteine was replaced by a positively charged amino acid. Thi

  19. Something Old and Something New: An Update on the Amazing Repertoire of Bacteriocins Produced by Streptococcus salivarius.

    Science.gov (United States)

    Wescombe, Philip A; Heng, Nicholas C K; Burton, Jeremy P; Tagg, John R

    2010-03-01

    Streptococcus salivarius has an exclusive and intimate association with humans. We are its sole natural host, and its contribution to the relationship appears overwhelmingly benevolent. Beautifully adapted to its preferred habitat, the human tongue, it only rarely ventures far from this location in the healthy host and indeed appears ill-equipped to become invasive due to a scarcity of virulence attributes. We consider that its strategically advantageous lingual location and numerical predominance allow S. salivarius to carry out a population surveillance and modulation role within the oral microbiota. Some strains are armed with complex arrays of targeted antibiotic weaponry, much of which belongs to the lantibiotic class of bacteriocins and a key to their ability to assemble and utilize this armament is their possession of transmissible multi-bacteriocin-encoding megaplasmid DNA. This review traces the origins of research into S. salivarius bacteriocins and bacteriocin-like inhibitory substances, showcases some of the inhibitory activities that we currently have knowledge of, and speculates about potential directions for ongoing investigation and probiotic application of this previously under-rated human commensal.

  20. 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 ...

  1. 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.

  2. 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

    2017-01-01

    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. PMID:28165017

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

    Science.gov (United States)

    Nielsen, Dennis S; Cho, Gyu-Sung; Hanak, Alexander; Huch, Melanie; Franz, Charles M A P; Arneborg, Nils

    2010-07-31

    A wide range of lactic acid bacteria (LAB) produce bacteriocins mainly active against other closely related LAB, but some bacteriocins are also active against the food-borne pathogen Listeria monocytogenes. With the aim of increasing food safety it has thus been considered to utilise bacteriocins 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 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. Expression levels of plantaricin-encoding genes by sessile and planktonic L. plantarum were determined using qRT-PCR. L.plantarum BFE 5092 possesses the genes for plantaricin EF, JK and N, while L. plantarum PCS 20 contains the genes for plantaricin EF, although determination of the nucleotide sequence of the PCS 20 plantaricin E gene showed that this peptide is probably non-functional. When cultured as mono-culture, both L. monocytogenes strains maintained pH(i) at a constant level around 7.2-7.6 throughout the experiment, independently of the matrix. On a solid surface, L. plantarum BFE 5092 strongly affected pH(i) of L. monocytogenes N53-1 with only 20% of the cells being able to maintain pH(i) in the physiological optimal range with pH>7 and 52% of the cells with pH(i) approximately pH(ex,) showing that the cells had no proton gradient towards the environment. The effect on L. monocytogenes EGDe was less pronounced, but still notable. L.plantarum PCS 20 left both strains of L. monocytogenes virtually unaffected when co-cultured on a solid surface. In liquid, both L. plantarum

  4. Gluconacetobacter diazotrophicus, a sugar cane endosymbiont, produces a bacteriocin against Xanthomonas albilineans, a sugar cane pathogen.

    Science.gov (United States)

    Piñón, Dolores; Casas, Mario; Blanch, María; Fontaniella, Blanca; Blanco, Yolanda; Vicente, Carlos; Solas, María-Teresa; Legaz, María-Estrella

    2002-01-01

    Gluconacetobacter diazotrophicus in liquid culture secretes proteins into the medium. Both medium containing Gluconacetobacter protein and a solution of this protein after acetone precipitation appeared to inhibit the growth of Xanthomonas albilineans in solid culture. This apparent inhibition of bacterial growth has, in fact, been revealed to be lysis of bacterial cells, as demonstrated by transmission electron microscopy. Fractionation of the Gluconacetobacter protein mixture in size-exclusion chromatography reveals a main fraction with lysozyme-like activity which produces lysis of both living bacteria and isolated cell walls.

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

    Directory of Open Access Journals (Sweden)

    Izildinha Moreno

    1999-04-01

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

  6. Bacteriocin-based strategies for food biopreservation.

    Science.gov (United States)

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

    2007-11-30

    Bacteriocins are ribosomally-synthesized peptides or proteins with antimicrobial activity, produced by different groups of bacteria. Many lactic acid bacteria (LAB) produce bacteriocins with rather broad spectra of inhibition. Several LAB bacteriocins offer potential applications in food preservation, and the use of bacteriocins in the food industry can help to reduce the addition of chemical preservatives as well as the intensity of heat treatments, resulting in foods which are more naturally preserved and richer in organoleptic and nutritional properties. This can be an alternative to satisfy the increasing consumers demands for safe, fresh-tasting, ready-to-eat, minimally-processed foods and also to develop "novel" food products (e.g. less acidic, or with a lower salt content). In addition to the available commercial preparations of nisin and pediocin PA-1/AcH, other bacteriocins (like for example lacticin 3147, enterocin AS-48 or variacin) also offer promising perspectives. Broad-spectrum bacteriocins present potential wider uses, while narrow-spectrum bacteriocins can be used more specifically to selectively inhibit certain high-risk bacteria in foods like Listeria monocytogenes without affecting harmless microbiota. Bacteriocins can be added to foods in the form of concentrated preparations as food preservatives, shelf-life extenders, additives or ingredients, or they can be produced in situ by bacteriocinogenic starters, adjunct or protective cultures. Immobilized bacteriocins can also find application for development of bioactive food packaging. In recent years, application of bacteriocins as part of hurdle technology has gained great attention. Several bacteriocins show additive or synergistic effects when used in combination with other antimicrobial agents, including chemical preservatives, natural phenolic compounds, as well as other antimicrobial proteins. This, as well as the combined use of different bacteriocins may also be an attractive approach to

  7. Screening for anti-listerial bacteriocin-producing lactic acid bacteria from "Gueddid" a traditionally Tunisian fermented meat.

    Science.gov (United States)

    Ben Belgacem, Zouhaier; Ferchichi, Mounir; Prévost, Hervé; Dousset, Xavier; Manai, Mohamed

    2008-04-01

    Forty eight lactic acid bacteria strains isolated from "Gueddid", a traditionally Tunisian fermented meat, were screened for bacteriocin production. Four strains named MMZ 04, 09, 13, and 17 showed antimicrobial activity and were identified as Enterococcus faecium by molecular methods based on the 16S-23S rDNA ISR, PCR-RFLP analysis of the 16S-23S rDNA ISR and species-specific primers. The four antimicrobial compounds were heat stable (121°C for 15min), active over a wide pH range (3-9) and the antimicrobial activity was lost after treatment with trypsin, α-chymotrypsin and proteinase K but not by lysozyme and lipase. The mode of action of enterocin MMZ17 was identified as bactericidal. The MMZ17 bacteriocin was partially purified by ammonium sulphate precipitation and C(18) Sep-Pack chromatography. The apparent molecular size of enterocin MMZ17 as indicated by activity detection after SDS-PAGE was lower than 6.5 KDa. According to these assays, enterocin MMZ17 can be classified as a small, heat-stable Listeria-active peptide, presumably belonging to class IIa bacteriocins.

  8. 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.

  9. Bacteriocin-producing strains of Lactobacillus plantarum inhibit adhesion of Staphylococcus aureus to extracellular matrix: quantitative insight and implications in antibacterial therapy.

    Science.gov (United States)

    Mukherjee, Sandipan; Ramesh, Aiyagari

    2015-12-01

    In the present study, the adhesion of bacteriocin-producing probiotic strains of Lactobacillus plantarum onto extracellular matrix (ECM) proteins such as collagen and mucin and their potential to prevent pathogen invasion onto the ECM was ascertained. Fluorescence-based in vitro assays indicated that L. plantarum strains CRA21, CRA38 and CRA52 displayed considerable adhesion to ECM molecules, which was comparable to the probiotic Lactobacillus rhamnosus GG. Flow cytometry-based quantitative assessment of the adhesion potential suggested that L. plantarum CRA21 exhibited superior adhesion onto the ECM as compared with other lactic acid bacteria strains. Furthermore, fluorescence-based assays suggested that the highest inhibition of Staphylococcus aureus adhesion onto collagen and mucin by bacteriocin-producing L. plantarum strains was observed in the exclusion mode as compared with the competition and displacement modes. This observation was supported by the higher binding affinity (k(d)) for the ECM exhibited by the L. plantarum strains as compared with S. aureus. Interestingly, a crude plantaricin A extract from food isolates of L. plantarum displayed potent antibacterial activity on ECM-adhered S. aureus cells. It is envisaged that the L. plantarum isolates displaying bacteriocinogenic and ECM-adhering traits can perhaps be explored to develop safe antibacterial therapeutic agents.

  10. Current advances and prospects of researches on the bacteriocins produced by Lactobacillus sakei%清酒乳杆菌细菌素研究的现状及展望

    Institute of Scientific and Technical Information of China (English)

    姜洁; 施波; 方佳琪; 陈晓琳; 祁克宗; 张明

    2011-01-01

    In addition to using the strains of Lactobacillus sakei as the starter cultures to develop the flavor and quality of sausage, most of the bacteriocins from L. sakei have strong inhibitory effects on pathogenic Listeria monocytogenes.There are various bacteriocins produced by L. sakei, and these bacteriocins have different properties. In this paper, the types of bacteriocins from L. sakei, the effect of meat products storage conditions ( or meat production condition) on the stability of L. sakei and bacteriocins, as well as application of bacteriocins from L. sakei as the food preservation were reviewed. This review is aimed at providing a reference for discovering new bacteriocins from L. sakei.%清酒乳杆菌不仅可作为发酵香肠的发酵剂赋予香肠良好的风味和品质,而且绝大多数清酒乳杆菌细菌素对食源性致病菌单核增生李斯特菌具有较强的抑制作用.清酒乳杆菌细菌素种类多,性质各异.本文分别从清酒乳杆菌细菌素的种类,肉制品环境对清酒乳杆菌和细菌素稳定性的影响以及清酒乳杆菌细菌素在食品中的应用研究进行了概述,为寻找新的具有良好性能的清酒乳杆菌细菌素提供了参考.

  11. Bacteriocins and Their Applications in Food Preservation.

    Science.gov (United States)

    Ramu, Ramith; Shirahatti, Prithvi S; Devi, Aishwarya T; Prasad, Ashwini; J, Kumuda; M S, Lochana; F, Zameer; B L, Dhananjaya; M N, Nagendra Prasad

    2015-07-20

    Bacteriocins are ribosomally-synthesized antimicrobial peptides or proteinaceous compounds produced by bacterial strains. They are generally effective in inhibiting the growth of similar or closely related bacterial strains. A high diversity of various bacteriocins is produced by many lactic acid bacteria (LAB) and is found in numerous fermented and non-fermented foods. Several bacteriocins from LAB extend potential applications in food preservation, thus help foods to be naturally preserved and richer in organoleptic and nutritional properties. Though chemical preservatives for the preservation of food are successful to some extent, their quality is not as satisfying as fresh food. Hence, an alternative is required and bacteriocins serve the purpose. Nisin is currently the only bacteriocin widely used as a food preservative. Numerous bacteriocins have been characterized chemically, biochemically, genetically and also at the molecular level to understand their basic mode of action. This article gives an overview of classification of bacteriocins, isolation & characterization, and mode of action. Besides, article highlights the optimized parameters for growth of bacteria in the production of bacteriocins and various bioassays for their determination. Special emphasis has been provided on explaining the beneficial aspects of nisin.

  12. 枯草芽孢杆菌3-2产细菌素发酵条件的优化%Optimization of Fermentation Condition in Bacteriocin Produced by Prunella Bacillus 3-2

    Institute of Scientific and Technical Information of China (English)

    杨宇清; 郑一敏; 胡杨; 乐亮; 江娟; 王宁; 林海珠

    2011-01-01

    To obtain optimal fermentation conditions of bacteriocin produced by prunella bacillus 3-2,the medial components and cultural conditions for producing bacteriocin of prunella bacillus 3-2 were optimized by single factor test in shake-flask.Results showed that BPY was suitable for producing bacteriocin.The optimum culture conditions were fermented 24h,at temperature 35℃ with starting pH at 7.0,medium volume 100ml in 500ml flask,inoculum volume 3% and seed aged were 12h.Conclusion is that it improves the bacteriocin production by optimal fermentation conditions.%采用单因素法,通过摇瓶培养,对枯草芽孢杆菌3-2产细菌素的发酵培养基和发酵条件进行优化。结果表明:产细菌素的最佳培养基是BPY培养基,最适合发酵时间为24 h,最适发酵温度为35℃,最适起始pH值为7.0,最适装液量为100 mL/500 mL,最适接种量为3%,最适接种龄为12 h。通过优化发酵条件可提高细菌素的产量。

  13. Identification, characterization, and recombinant expression of epidermicin NI01, a novel unmodified bacteriocin produced by Staphylococcus epidermidis that displays potent activity against Staphylococci.

    Science.gov (United States)

    Sandiford, Stephanie; Upton, Mathew

    2012-03-01

    We describe the discovery, purification, characterization, and expression of an antimicrobial peptide, epidermicin NI01, which is an unmodified bacteriocin produced by Staphylococcus epidermidis strain 224. It is a highly cationic, hydrophobic, plasmid-encoded peptide that exhibits potent antimicrobial activity toward a wide range of pathogenic Gram-positive bacteria including methicillin-resistant Staphylococcus aureus (MRSA), enterococci, and biofilm-forming S. epidermidis strains. Purification of the peptide was achieved using a combination of hydrophobic interaction, cation exchange, and high-performance liquid chromatography (HPLC). Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) analysis yielded a molecular mass of 6,074 Da, and partial sequence data of the peptide were elucidated using a combination of tandem mass spectrometry (MS/MS) and de novo sequencing. The draft genome sequence of the producing strain was obtained using 454 pyrosequencing technology, thus enabling the identification of the structural gene using the de novo peptide sequence data previously obtained. Epidermicin NI01 contains 51 residues with four tryptophan and nine lysine residues, and the sequence showed approximately 50% identity to peptides lacticin Z, lacticin Q, and aureocin A53, all of which belong to a new family of unmodified type II-like bacteriocins. The peptide is active in the nanomolar range against S. epidermidis, MRSA isolates, and vancomycin-resistant enterococci. Other unique features displayed by epidermicin include a high degree of protease stability and the ability to retain antimicrobial activity over a pH range of 2 to 10, and exposure to the peptide does not result in development of resistance in susceptible isolates. In this study we also show the structural gene alone can be cloned into Escherichia coli strain BL21(DE3), and expression yields active peptide.

  14. Bacteriocins - a viable alternative to antibiotics?

    Science.gov (United States)

    Cotter, Paul D; Ross, R Paul; Hill, Colin

    2013-02-01

    Solutions are urgently required for the growing number of infections caused by antibiotic-resistant bacteria. Bacteriocins, which are antimicrobial peptides produced by certain bacteria, might warrant serious consideration as alternatives to traditional antibiotics. These molecules exhibit significant potency against other bacteria (including antibiotic-resistant strains), are stable and can have narrow or broad activity spectra. Bacteriocins can even be produced in situ in the gut by probiotic bacteria to combat intestinal infections. Although the application of specific bacteriocins might be curtailed by the development of resistance, an understanding of the mechanisms by which such resistance could emerge will enable researchers to develop strategies to minimize this potential problem.

  15. Synthesis of lactococcin 972, a bacteriocin produced by Lactococcus lactis IPLA 972, depends on the expression of a plasmid-encoded bicistronic operon

    NARCIS (Netherlands)

    Martínez, B.; Fernández, M.; Suárez, J.E.; Rodríguez, A.

    1999-01-01

    Synthesis of lactococcin 972 is plasmid-encoded. An operon composed of two genes that encode pre-bacteriocin and a putative immunity protein has been identified. The first gene encodes a 91-residue polypeptide that is exported via a sec-dependent system to give the mature 66-aa bacteriocin. The immu

  16. Synthesis of lactococcin 972, a bacteriocin produced by Lactococcus lactis IPLA 972, depends on the expression of a plasmid-encoded bicistronic operon

    NARCIS (Netherlands)

    Martínez, B.; Fernández, M.; Suárez, J.E.; Rodríguez, A.

    1999-01-01

    Synthesis of lactococcin 972 is plasmid-encoded. An operon composed of two genes that encode pre-bacteriocin and a putative immunity protein has been identified. The first gene encodes a 91-residue polypeptide that is exported via a sec-dependent system to give the mature 66-aa bacteriocin. The immu

  17. Diversity and applications of Bacillus bacteriocins.

    Science.gov (United States)

    Abriouel, Hikmate; Franz, Charles M A P; Ben Omar, Nabil; Gálvez, Antonio

    2011-01-01

    Members of the genus Bacillus are known to produce a wide arsenal of antimicrobial substances, including peptide and lipopeptide antibiotics, and bacteriocins. Many of the Bacillus bacteriocins belong to the lantibiotics, a category of post-translationally modified peptides widely disseminated among different bacterial clades. Lantibiotics are among the best-characterized antimicrobial peptides at the levels of peptide structure, genetic determinants and biosynthesis mechanisms. Members of the genus Bacillus also produce many other nonmodified bacteriocins, some of which resemble the pediocin-like bacteriocins of the lactic acid bacteria (LAB), while others show completely novel peptide sequences. Bacillus bacteriocins are increasingly becoming more important due to their sometimes broader spectra of inhibition (as compared with most LAB bacteriocins), which may include Gram-negative bacteria, yeasts or fungi, in addition to Gram-positive species, some of which are known to be pathogenic to humans and/or animals. The present review provides a general overview of Bacillus bacteriocins, including primary structure, biochemical and genetic characterization, classification and potential applications in food preservation as natural preservatives and in human and animal health as alternatives to conventional antibiotics. Furthermore, it addresses their environmental applications, such as bioprotection against the pre- and post-harvest decay of vegetables, or as plant growth promoters.

  18. Theoretical Models for Producing Circularly Polarized Radiation in Extragalactic Radio Sources

    CERN Document Server

    Wardle, J F C; Wardle, John F. C.; Homan, Daniel C.

    2003-01-01

    We discuss the production of circular polarization in compact radio sources both by the intrinsic mechanism and by Faraday conversion. We pay particular attention to the magnetic field structure, considering partially ordered fiel ds and Laing sheets, and distinguishing between uniform and unidirectional fields. (The latter can be constrained b y flux conservation arguments.) In most cases, Faraday conversion is the more important mechanism. Conversion opera tes on Stokes U, which can be generated by internal Faraday rotation, or by magnetic field fluctuations, which can therefore produce circular polarization even in a pure pair plasma. We also show that the spectrum of circular pola rization in an inhomogeneous jet can be quite different from that in a uniform source, being flat or even inverted.

  19. Are bacteriocins underexploited? Novel applications for old antimicrobials.

    Science.gov (United States)

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

    2011-08-01

    Bacteriocins are ribosomally synthesized (poly)peptides produced by almost all prokaryotic lineages. Bacteriocins from lactic acid bacteria (LAB) and bacteriocin-producer probiotic organisms have been thoroughly studied due to their wide spectra of action, the long-term use in food fermentations and the consideration of these microorganisms as beneficial for human beings. Most of the studies on the biotechnological application of diverse bacteriocins have been focused on their use as food preservatives, nisin being the prototype successfully used in alimentation. However, bacteriocins from LAB have demonstrated a remarkable potential as therapeutics for medical or veterinary uses, alone or in combination with classical antimicrobials. Their interest is even higher now that the resistance to the antibacterials used in therapeutics is growing. In this review we explore exciting opportunities for bacteriocin and probiotic applications, highlighting the possibilities for new and innovative research in order to give the necessary attention to this type of natural molecules that exhibit a great potential.

  20. Classification of Bacteriocins from Gram-Positive Bacteria

    Science.gov (United States)

    Rea, Mary C.; Ross, R. Paul; Cotter, Paul D.; Hill, Colin

    Bacteriocins are ribosomally synthesised antimicrobial peptides produced by bacteria, including many Gram-positive species. The classification of bacteriocins from Gram-positive bacteria is complicated by their heterogeneity and thus, as the number of Gram-positive bacteriocins identified has continued to increase, classification schemes have had to continuously evolve. Here, we review the various classification approaches, both historical and current, their underlying scientific basis and their relative merit, and suggest a rational scheme given the state of the art.

  1. Anti-infective properties of bacteriocins: an update.

    Science.gov (United States)

    Hammami, Riadh; Fernandez, Benoit; Lacroix, Christophe; Fliss, Ismail

    2013-08-01

    Bacteriocin production is a widespread phenomenon among bacteria. Bacteriocins hold great promise for the treatment of diseases caused by pathogenic bacteria and could be used in the future as alternatives to existing antibiotics. The anti-infective potential of bacteriocins for inhibiting pathogens has been shown in various food matrices including cheese, meat, and vegetables. However, their inhibition of pathogens in vivo remains unclear and needs more investigation, due mainly to difficulties associated with demonstrating their health benefits. Many bacteriocins produced by established or potential probiotic organisms have been evaluated as potential therapeutic agents and interesting findings have been documented in vitro as well as in a few in vivo studies. Some recent in vivo studies point to the efficacy of bacteriocin-based treatments of human and animal infections. While further investigation remains necessary before the possibilities for bacteriocins in clinical practice can be described more fully, this review provides an overview of their potential applications to human and veterinary health.

  2. Study on Fermentation Condition of Lactobacillus on Producing Bacteriocin and Antibacterial Spectrum of Antibacterial Compounds%乳杆菌产细菌素的发酵条件及其抑菌谱的研究

    Institute of Scientific and Technical Information of China (English)

    陈忠军; 张保军; 于娜

    2013-01-01

    本研究以从内蒙古地区传统谷物发酵食品-酸粥中筛选出的产细菌素的乳杆菌为对象,对其产细菌素的发酵条件进行优化,并确定其抑菌谱。结果表明乳杆菌SZL-1的最佳发酵条件为:接种量7%,培养基起始pH 6.0,发酵时间24h,培养温度37℃。乳杆菌SZL-1产生的细菌素抑菌谱较广,对大多数革兰氏阴性和革兰氏阳性菌都有抑菌作用,但对酵母菌无抑菌作用。%The strains producing bacteriocin was screened from traditional grain fermentation food Acid-Gruel in Inner Mongolia. The fermentation condition of producing bacteriocin and antibacterial spectrum of antibacterial compounds was studied. By single factor experiments and orthogonal experiments , the fermentation condition for SZL-1 on production of bacteriocin was optimized. The result showed that the optimum inoculation quantity is 7%, initial pH was 6.0, culturing at 37℃ for 24 hours. Moreover bacteriocin produced by SZL-1 had obvious inhibit activity on antibacterial upon most of Gram-positive and Gram-negative bacteria , but no action on yeast. And antibacterial spectrum was wide.

  3. Class IId or Linear and Non-Pediocin-Like Bacteriocins

    Science.gov (United States)

    Iwatani, Shun; Zendo, Takeshi; Sonomoto, Kenji

    Class IId bacteriocins are one of the subclasses of class II bacteriocins produced by lactic acid bacteria. This class of bacteriocins, however, show a great diversity in their primary structures and modes of action. This chapter focuses on two aspects: (1) the description of those heterogeneous bacteriocins with the concept of three potential subgroups and (2) the modes of action of lactococcin A, lactococcin 972, and lacticin Q, each of which belongs to a different subgroup and is well characterized in its unique mode of action.

  4. 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.

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

    Science.gov (United States)

    Belguesmia, Y.; Choiset, Y.; Prévost, H.; Dalgalarrondo, M.; Chobert, J.-M.; Drider, D.

    2010-01-01

    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, α-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. PMID:20811593

  6. 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.

  7. Quorum sensing in class Ⅱ bacteriocin-producing lactic acid bacteria and its application - A review%产Ⅱ类细菌素乳酸菌群体感应及其应用

    Institute of Scientific and Technical Information of China (English)

    张香美; 李平兰

    2011-01-01

    群体感应( quorum sensing,QS)是微生物通过感知与细胞密度相关的信号分子的浓度来调控基因表达的一种行为.许多产Ⅱ类细菌素乳酸菌通过自诱导肽介导的QS系统调控其细菌素的合成.本文综述了乳酸菌Ⅱ类细菌素合成的QS调控现象、调控机制、QS系统组分以及QS的应用.产Ⅱ类细菌素乳酸菌QS的研究,必将为揭示发酵调控机理、调控发酵过程提供新的研究平台,为食品级基因表达系统的开发提供新的选择.%Quorum sensing ( QS) refers to the behavior of microorganisms to control gene expression through detection the concentration of certain signal molecules, which is correlated with cell density. In many class II bacteriocin-producing lactic acid bacteria ( LAB ) , bacteriocin production is regulated by peptide pheromones via a QS mechanism. We reviewed, QS regulated class II bacteriocin production in LAB and its regulation mechanism, components of the QS system, as well as the application of QS mechanism. The study of QS mechanism of class II bacteriocin-producing LAB may provide a new platform for revealing the mechanism of fermentation control and regulating fermentation process. It also offers an alternative to the exploitation of food grade gene expression system.

  8. Detection and preliminary characterization of a narrow spectrum bacteriocin produced by Lactobacillus pentosus K2N7 from Thai traditional fermented shrimp (Kung-Som

    Directory of Open Access Journals (Sweden)

    Nisit Watthanasakphuban

    2016-02-01

    Full Text Available A total of 48 lactic acid bacteria (LAB exhibited antagonistic activity against Lactobacillus sakei subsp. sakei JCM 1157 or Staphylococcus aureus DMST 8840. Only strain K2N7 was selected for characterization of bacteriocin activity. It was identified as Lactobacillus pentosus based on 16S rDNA analysis. The maximum bacteriocin production was detected in early stationary phase of growth. It was found to be sensitive to proteolytic enzymes (trypsin, proteinase K, pronase E and -chymotrypsin. The bacteriocin K2N7 was heat stable (2 h at 100ºC and retained activity over a wide pH range (2.0-12.0. Bacteriocin K2N7 has a narrow inhibitory spectrum restricted to genus Lactobacillus including Lactobacillus plantarum D6SM3, a bacterial strain known to cause overfermentation in Kung-Som. The peptide was purified by 60% ammonium sulphate precipitation followed by sequential cation exchange chromatography and hydrophobic interaction characteristic. The molecular mass of bacteriocin K2N7 (2.017 kDa was determined by matrix-assisted laser desorption/ionization time-offlight mass spectrometry analysis (MALDI-TOF MS.

  9. Bacteriocin-mediated competition in cystic fibrosis lung infections

    DEFF Research Database (Denmark)

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

    2015-01-01

    Bacteriocins are toxins produced by bacteria to kill competitors of the same species. Theory and laboratory experiments suggest that bacteriocin production and immunity play a key role in the competitive dynamics of bacterial strains. The extent to which this is the case in natural populations, e...

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

    Science.gov (United States)

    2015-03-30

    FERMENTATION CONDITIONS FOR THE PRODUCTION OF BACTERIOCIN “ FERMENTATE ” by Anthony Sikes Wayne Muller and Claire Lee March 2015...From - To) October 2010 – November 2013 4. TITLE AND SUBTITLE OPTIMIZATION OF FERMENTATION CONDITIONS FOR THE PRODUCTION OF BACTERIOCIN “ FERMENTATE ...nisin and pediocin. Whey + yeast extract was the best performing whey fermentation media. The nisin producer strain Lactococcus. lactis ssp. lactis was

  11. Bacteriocins : mechanism of membrane insertion and pore formation

    NARCIS (Netherlands)

    Moll, Gert N.; Konings, Wil N.; Driessen, Arnold 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

  12. 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

  13. Bacteriocin Antibacterial Activity Produced by Lactobacillus helveticus Isolated Jianchang Dry-cured Duck%瑞士乳杆菌产生的细菌素的抑菌活性研究

    Institute of Scientific and Technical Information of China (English)

    林巧

    2015-01-01

    The antibacterial activity of this experiment by studying bacteriocins produced by Lactobacillus helveticus was investigated at different temperatures, different pH, different types of enzymes on the antibacterial activity of bacteriocin. Results showed that: proteinase can be a certain extent the antibacterial activity of bacteriocin, trypsin inhibition of the strongest; the antibacterial activity of the bacteriocin on the temperature tolerance and strong, even after treated at 100 ℃ has antibacterial activity, the st rongest antibacterial activity when stored at-20℃;the bacterial factors pH of 1.5 to 4.0 with antibacterial activity and antibacterial activity of the strongest at pH 1.5.%主要通过研究对从建昌板鸭发酵过程中分离瑞士乳杆菌产生细菌素的抑菌活性,考察不同温度,不同pH,不同种类酶作用对细菌素抑菌活性的影响。结果证明:蛋白酶能一定程度抑制细菌素的抑菌活性,且胰蛋白酶的抑制程度最强;该细菌素的抑菌活性对温度的耐受力强,即使在100℃处理后仍具有抑菌活性,在-20℃条件下保存时抑菌活性最强;该细菌素pH在1.5~4.0时具有抑菌活性,在pH为1.5时抑菌活性最强。

  14. Lactobacillus salivarius: bacteriocin and probiotic activity.

    Science.gov (United States)

    Messaoudi, S; Manai, M; Kergourlay, G; Prévost, H; Connil, N; Chobert, J-M; Dousset, X

    2013-12-01

    Lactic acid bacteria (LAB) antimicrobial peptides typically exhibit antibacterial activity against food-borne pathogens, as well as spoilage bacteria. Therefore, they have attracted the greatest attention as tools for food biopreservation. In some countries LAB are already extensively used as probiotics in food processing and preservation. LAB derived bacteriocins have been utilized as oral, topical antibiotics or disinfectants. Lactobacillus salivarius is a promising probiotic candidate commonly isolated from human, porcine, and avian gastrointestinal tracts (GIT), many of which are producers of unmodified bacteriocins of sub-classes IIa, IIb and IId. It is a well-characterized bacteriocin producer and probiotic organism. Bacteriocins may facilitate the introduction of a producer into an established niche, directly inhibit the invasion of competing strains or pathogens, or modulate the composition of the microbiota and influence the host immune system. This review gives an up-to-date overview of all L. salivarius strains, isolated from different origins, known as bacteriocin producing and/or potential probiotic.

  15. Genome sequence of Lactococcus garvieae IPLA 31405, a bacteriocin-producing, tetracycline-resistant strain isolated from a raw-milk cheese

    OpenAIRE

    Flórez García, Ana Belén; Reimundo, Pilar; Delgado, Susana; Fernández, Elena; Alegría, Ángel; Guijarro, José A; Mayo Pérez, Baltasar

    2012-01-01

    This work describes the draft genome sequence of Lactococcus garvieae IPLA 31405, isolated from a traditional Spanish cheese. The genome contains a lactose-galactose operon,a bacteriocin locus, two integrated phages, a transposon harboring an active tet(M) gene, and two theta-type plasmid replicons. Genes encoding virulence factors were not recorded. © 2012, American Society for Microbiology.

  16. Kinetic studies of the action of Lactacin F, a bacteriocin produced by Lactobacillus johnsonii that forms poration complexes in the cytoplasmic membrane.

    NARCIS (Netherlands)

    Abee, T.; Klaenhammer, T.R.; Letellier, L.

    1994-01-01

    The bacteriocin lactacin F is bactericidal against Lactobacillus delbrueckii, Lactobacillus helveticus, and Enterococcus faecalis. Activity against L. delbrueckii was recently shown to be dependent on two peptides, LafA and LafX, which are encoded within the lactacin F operon (T. R. Klaenhammer, FEM

  17. Purification and characterization of thermophilin T, a novel bacteriocin produced by Streptococcus thermophilus ACA-DC 0040

    NARCIS (Netherlands)

    Aktypis, A.; Kalantzopoulos, G.; Huis Veld,in't J.H.J.; Brink, B. ten

    1998-01-01

    ACA-DC 0040 produced an antimicrobial agent, which was named thermophilin T, active against several lactic acid bacteria strains of different species and food spoilage bacteria, such as Clostridium sporogenes C22/10 and Cl. tyrobutyricum NCDO-1754. The crude antimicrobial compound is sensitive to pr

  18. CHARACTERIZATION OF ANTILISTERIAL BACTERIOCINS PRODUCED BY E. FAECIUM AND E. DURANS ISOLATES FROM HISPANIC-STYLE CHEESES

    Science.gov (United States)

    Enterococci are often identified as constituents of the indigenous microflora from raw milk artisanal cheeses and are believed to contribute to the unique organoleptic qualities of these products. Many strains of enterococci are also known to produce antimicrobial peptides, enterocins, which may pr...

  19. Purification and characterization of thermophilin T, a novel bacteriocin produced by Streptococcus thermophilus ACA-DC 0040

    NARCIS (Netherlands)

    Aktypis, A.; Kalantzopoulos, G.; Huis Veld,in't J.H.J.; Brink, B. ten

    1998-01-01

    ACA-DC 0040 produced an antimicrobial agent, which was named thermophilin T, active against several lactic acid bacteria strains of different species and food spoilage bacteria, such as Clostridium sporogenes C22/10 and Cl. tyrobutyricum NCDO-1754. The crude antimicrobial compound is sensitive to pr

  20. Purification and characterization of thermophilin T, a novel bacteriocin produced by Streptococcus thermophilus ACA-DC 0040

    NARCIS (Netherlands)

    Aktypis, A.; Kalantzopoulos, G.; Huis Veld,in't J.H.J.; Brink, B. ten

    1998-01-01

    ACA-DC 0040 produced an antimicrobial agent, which was named thermophilin T, active against several lactic acid bacteria strains of different species and food spoilage bacteria, such as Clostridium sporogenes C22/10 and Cl. tyrobutyricum NCDO-1754. The crude antimicrobial compound is sensitive to

  1. A new structure-based classification of gram-positive bacteriocins.

    Science.gov (United States)

    Zouhir, Abdelmajid; Hammami, Riadh; Fliss, Ismail; Hamida, Jeannette Ben

    2010-08-01

    Bacteriocins are ribosomally-synthesized peptides or proteins produced by a wide range of bacteria. The antimicrobial activity of this group of natural substances against foodborne pathogenic and spoilage bacteria has raised considerable interest for their application in food preservation. Classifying these bacteriocins in well defined classes according to their biochemical properties is a major step towards characterizing these anti-infective peptides and understanding their mode of action. Actually, the chosen criteria for bacteriocins' classification lack consistency and coherence. So, various classification schemes of bacteriocins resulted various levels of contradiction and sorting inefficiencies leading to bacteriocins belonging to more than one class at the same time and to a general lack of classification of many bacteriocins. Establishing a coherent and adequate classification scheme for these bacteriocins is sought after by several researchers in the field. It is not straightforward to formulate an efficient classification scheme that encompasses all of the existing bacteriocins. In the light of the structural data, here we revisit the previously proposed contradictory classification and we define new structure-based sequence fingerprints that support a subdivision of the bacteriocins into 12 groups. The paper lays down a resourceful and consistent classification approach that resulted in classifying more than 70% of bacteriocins known to date and with potential to identify distinct classes for the remaining unclassified bacteriocins. Identified groups are characterized by the presence of highly conserved short amino acid motifs. Furthermore, unclassified bacteriocins are expected to form an identified group when there will be sufficient sequences.

  2. Potentiated anti-microsporidial activity of Lactobacillus acidophilus CH1 bacteriocin using gold nanoparticles.

    Science.gov (United States)

    Mossallam, Shereen F; Amer, Eglal I; Diab, Radwa G

    2014-09-01

    Through increased awareness and improved diagnostics, microsporidiosis has now been identified in a broader range of human populations; however current therapies are inconsistently effective. Recently, probiotics were determined as means for the control of intestinal parasitic infections through their secretory products; bacteriocins. This is the first study on the effect of bacteriocin produced by Lactobacillus acidophilus CH1 bacteriocin, with or without gold nanoparticles (Au-NPs), against intestinal microsporidiosis in immunosuppressed mice. Fecal and intestinal spore loads, besides viability, extrusion and infectivity of spores from treated animals were assessed. Results showed that the anti-microsporidial effects of bacteriocin were significantly potent. This efficiency was further potentiated upon conjugating bacteriocins with Au-NPs, as it induced a strikingly sustained reduction in fecal spore shedding after cessation of therapy by 1 week (94.26%). Furthermore, reduction in intestinal spore load was highest in bacteriocin/Au-NPs-inoculated mice (89.7%) followed by bacteriocin-inoculated group (73.5%). Spores encountered from stool of bacteriocin/Au-NPs group showed 92.4% viability, versus 93.7% in bacteriocin group. Spore extrusion and infectivity were most inhibited by exposure to bacteriocin/Au-NPs. Safety of bacteriocin/Au-NPs was also verified. Thus, considering the results of the present work, L. acidophilus CH1-derived bacteriocin can present a powerful safe therapy against intestinal microsporidiosis.

  3. 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

  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. 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

  6. Antibacterial peptides "bacteriocins": an overview of their diverse characteristics and applications.

    Science.gov (United States)

    Nishie, Mami; Nagao, Jun-Ichi; Sonomoto, Kenji

    2012-03-01

    Bacteriocins are ribosomally synthesized antibacterial peptides produced by bacteria that inhibit the growth of similar or closely related bacterial strains. A number of bacteriocins from a wide variety of bacteria have been discovered, and their diverse structures have been reported. Growing evidence suggests that bacteriocins have diverse structures, modes of action, mechanisms of biosynthesis and self-immunity, and gene regulation. Bacteriocins are considered as an attractive compound in food and pharmaceutical industries to prevent food spoilage and pathogenic bacterial growth. Furthermore, elucidation of their biosynthesis has led to the use of bacteriocin-controlled gene-expression systems and the biosynthetic enzymes of lantibiotics, a class of bacteriocins, as tools to design novel peptides. In this review, we summarize and discuss currently known information on bacteriocins produced by Gram-positive bacteria and their applications.

  7. 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.

  8. The role of bacteriocins as selfish genetic elements.

    Science.gov (United States)

    Inglis, R Fredrik; Bayramoglu, Bihter; Gillor, Osnat; Ackermann, Martin

    2013-06-23

    Bacteria produce a wide arsenal of toxic compounds in order to kill competing species. Bacteriocins, protein-based toxins produced by nearly all bacteria, have generally been considered a ubiquitous anti-competitor strategy, used to kill competing bacterial strains. Some of these bacteriocins are encoded on plasmids, which also code for closely linked immunity compounds (thereby rendering toxin producing cells immune to their own toxin). However, the production of bacteriocins can also be interpreted as a means to promote plasmid stability by preferentially selecting for cells carrying the plasmid. If, for example, a cell were to lose the plasmid, it would no longer produce the immunity compound and would be killed by its bacteriocin-producing clone mates. In this respect, bacteriocins can be regarded as similar to previously described toxin-antitoxin systems that are able promote the stable transmission of plasmids to daughter cells. In order to test this prediction, we carried out an experimental evolution study using the bacterium Escherichia coli, finding that bacteriocins can indeed select for the stable maintenance of plasmids. This suggests that bacteriocins can act primarily as selfish genetic elements promoting their own transmission in the population, which may help explain their unique ecology and evolution.

  9. Structural characterization of thioether-bridged bacteriocins.

    Science.gov (United States)

    Lohans, Christopher T; Vederas, John C

    2014-01-01

    Bacteriocins are a group of ribosomally synthesized antimicrobial peptides produced by bacteria, some of which are extensively post-translationally modified. Some bacteriocins, namely the lantibiotics and sactibiotics, contain one or more thioether bridges. However, these modifications complicate the structural elucidation of these bacteriocins using conventional techniques. This review will discuss the techniques and strategies that have been applied to determine the primary structures of lantibiotics and sactibiotics. A major challenge is to identify the topology of thioether bridges in these peptides (i.e., which amino-acid residues are involved in which bridges). Edman degradation, NMR spectroscopy and tandem MS have all been commonly applied to characterize these bacteriocins, but can be incompatible with the post-translational modifications present. Chemical modifications to the modified residues, such as desulfurization and reduction, make the treated bacteriocins more compatible to analysis by these standard peptide analytical techniques. Despite their differences in structure, similar strategies have proved useful to study the structures of both lantibiotics and sactibiotics.

  10. Bacteriocins synthesized by Bacillus thuringiensis: generalities and potential applications

    Science.gov (United States)

    Salazar-Marroquín, Elma Laura; Galán-Wong, Luis J.; Moreno-Medina, Víctor Ricardo; Reyes-López, Miguel Ángel; Pereyra-Alférez, Benito

    2016-01-01

    The members of the Bacillus thuringiensis group, commonly known as Bt, produce a huge number of metabolites, which show biocidal and antagonistic activity. B. thuringiensis is widely known for synthesizing Cry, Vip and Cyt proteins, active against insects and other parasporins with biocidal activity against certain types of cancerous cells. Nevertheless, B. thuringiensis also synthesizes compounds with antimicrobial activity, especially bacteriocins. Some B. thuringiensis bacteriocins resemble lantibiotics and other small linear peptides (class IIa) from the lactic acid bacteria bacteriocins classification system. Although many bacteriocins produced by Bt have been reported, there is no proper classification for them. In this work, we have grouped these based on molecular weight and functionality. Bacteriocins are small peptides synthesized by bacteria, presenting inhibitory activity against Gram-positive and Gram-negative bacteria and to a lesser extent against fungi. These molecules represent a good study model in the search for microbial control alternatives. Lactic acid bacteria produces a huge number of these types of molecules with great potential. Nonetheless, members of the Bacillus, cereus group, especially B. thuringiensis, emerge as an attractive alternative for obtaining bacteriocins showing novel activities. This review describes the potential applications of B. thuringiensis bacteriocins in the control of foodborne pathogens, environment and medical area. PMID:27340340

  11. Diversity and dynamics of bacteriocins from human microbiome.

    Science.gov (United States)

    Zheng, Jinshui; Gänzle, Michael G; Lin, Xiaoxi B; Ruan, Lifang; Sun, Ming

    2015-06-01

    Human commensal microbiota are an important determinant of health and disease of the host. Different human body sites harbour different bacterial microbiota, bacterial communities that maintain a stable balance. However, many of the factors influencing the stabilities of bacterial communities associated with humans remain unknown. In this study, we identified putative bacteriocins produced by human commensal microbiota. Bacteriocins are peptides or proteins with antimicrobial activity that contribute to the stability and dynamics of microbial communities. We employed bioinformatic analyses to identify putative bacteriocin sequences in metagenomic sequences obtained from different human body sites. Prevailing bacterial taxa of the putative bacteriocins producers matched the most abundant organisms in each human body site. Remarkably, we found that samples from different body sites contain different density of putative bacteriocin genes, with the highest in samples from the vagina, the airway, and the oral cavity and the lowest in those from gut. Inherent differences of different body sites thus influence the density and types of bacteriocins produced by commensal bacteria. Our results suggest that bacteriocins play important roles to allow different bacteria to occupy several human body sites, and to establish a long-term commensal relationship with human hosts.

  12. Screening the Best Fermentation Conditions of Bacteriocin Produced by Leuconostoc mesenteroides%肠膜明串珠菌产细菌素最适发酵条件的筛选

    Institute of Scientific and Technical Information of China (English)

    王琳琳; 郑一敏; 杨宇清; 胡杨; 胥秀英; 傅善权

    2011-01-01

    为获得肠膜明串珠茵产细茵素的最佳发酵条件,采用琼脂扩散法测定发酵液对革兰氏阳性细菌、革兰氏阴性细菌的抑菌活性,结果发现:产细茵素的最佳培养基是MRS培养基,最适起始pH值为6.4,最适接种的体积分数和接种种龄分别为3%和24 h,产细菌素最适发酵温度和时间分别为30℃和24 h.通过优化发酵条件提高了细菌素的产量.%Objective: To obtain the optimal fermentation conditions of hacteriocin produced by Leuconostoc mesenteroides strain. Method: The antibacterial activity of the fermentation liquid against Gram-positive bacteria and Gram-negative bacteria was tested by the method of agar diffusion assay. Results: MRS was shown to be more suitable for producing bacteriocin than 108 #. The optimum initial pH, inoculation amount. seed age and fermentation temperature and time were 6. 5, 3%, 24 hours and 30 ℃ and 24 hours, respectively. Conclusion: The optimization of fermentation conditions improved bacteriocin production by L. mesenteroides.

  13. 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.

  14. 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.

  15. Nanotechnology: A Valuable Strategy to Improve Bacteriocin Formulations

    Science.gov (United States)

    Fahim, Hazem A.; Khairalla, Ahmed S.; El-Gendy, Ahmed O.

    2016-01-01

    Bacteriocins are proteinaceous antibacterial compounds, produced by diverse bacteria, which have been successfully used as: (i) food biopreservative; (ii) anti-biofilm agents; and (iii) additives or alternatives to the currently existing antibiotics, to minimize the risk of emergence of resistant strains. However, there are several limitations that challenge the use of bacteriocins as biopreservatives/antibacterial agents. One of the most promising avenues to overcome these limitations is the use of nanoformulations. This review highlights the practical difficulties with using bacteriocins to control pathogenic microorganisms, and provides an overview on the role of nanotechnology in improving the antimicrobial activity and the physicochemical properties of these peptides. PMID:27695440

  16. Screening of bacteriocin-producing lactic acid bacteria in hogormag from Xinjiang and study on its bacteriostatic activity%新疆酸驼乳中细菌素乳酸菌的筛选及其抑菌性

    Institute of Scientific and Technical Information of China (English)

    武运; 李远; 王冰峰; 张晓燕; 阿伊古扎丽; 巴吐尔

    2011-01-01

    From 23 strains of lactic acid bacteria isolated from Hazakh traditional fermented camel milk, 9 Strains were screened out to exhibit inhibitory activity on S. aureus, B. subtilis and E. coli by doubledeck agar diffusion and punch methods. One strain of MLS5 exhibits the strongest antibacterial activity. The antimicrobial substance produced by MLS5 was initially identified as protein bacteriocin by inhib itive effect of organic acids and hydrogen peroxide exclusion and protease susceptibility test. Temperature and pH tolerance test showed that the bacteriocin still has thermal stability at 121 ℃ for 20 minutes and antibacterial activity at pH 3 ~ 6. Fermentation curve of strain MLS5 showed that the strain was capacity of producing bacteriocin and acid at the temperature of 37 ℃. The bacteriocin was generated from mid-logarithmic growth phase and reached the maximum activity at stationary phase. The inhibitory spectrum results showed that the bacteriocin produced by MLS5 exhibits broad antibacterial spectrum. It can not only inhibit the Gram-positive bacteria, but also inhibit E. coli and Mucor.%通过双层琼脂扩散打孔法,从新疆哈萨克族传统发酵酸驼乳中分离的23株乳酸菌中,筛选出9株对金黄色葡萄球菌、枯草芽孢杆菌和大肠杆菌具有抑菌活性的菌株(其中茵株MLS5抑菌活性最强).通过有机酸、过氧化氢抑茵的排除试验和蛋白酶敏感性试验,初步确定MLS5产生的抑茵物质为蛋白质类细菌素.温度和pH耐受试验表明,该细菌素具有良好的热稳定性(121℃,20 min),pH 3~6具有抑茵活性.菌株MLS5的发酵曲线表明,菌株在37℃培养条件下具有良好的产细菌素和产酸能力,该细茵素在茵体生长对数中期产生,在生长稳定期抑茵活性达到最大.经抑茵谱试验表明,MLS5所产细菌素不仅能抑制革兰氏阳性细茵,而且对大肠杆菌和毛霉菌也有抑制作用,具有较广的抑茵谱.

  17. Screening, Identification and Toxicity of a Strain of Wide pH Spectrum Bacteriocin-Producing Lactic Acid Bacteria and Characterization of Bacteriocin Produced by It%产宽谱pH细菌素乳酸菌的筛选鉴定、毒力检测及细菌素特性研究

    Institute of Scientific and Technical Information of China (English)

    周佳; 刘书亮; 胡欣洁; 张元娥

    2012-01-01

    SAU-2,a bacteriocin-producing strain,was screened out of 34 strains isolated from milk residue in West Sichuan plateau.The strain was identified as Enterococcus based on colonial morphology,physiological and biochemical characteristics and 16S rDNA sequence phylogenetic analysis.SAU-2 had no hemolytic activity.All the virulence factors of agg,gelE,cylM,cylB,cylA,esp,efaAfm,cpd,cob,ccf,cyILL,cyILS,fsrB and hyLEfm were negative.These results indicate that SAU-2 is safe.In addition,bacteriocin produced by SAU-2 could tolerate heat treatment at 121 ℃ for 20 min,and exhibited antibacterial activity at pH 2.0-12.0,but was sensitive to trypsin and proteinase K.It showed strong inhibitory effect on relative strains of SAU-2 and Gram-positive bacteria,and could also inhibit one strain of Pseudomonas aeruginosa and one strain of Rhodotorula glutinis,but had no inhibitory effect on other Gram-negative bacteria and fungi.%采用琼脂扩散法从分离自川西高原奶渣的34株疑似乳酸球菌中筛选细菌素产生菌,初筛检测发酵上清液抑菌活性,复筛排除有机酸和H2O2干扰,检测蛋白酶敏感性,测定抑菌物质盐析液和粗提液抑菌活性,确定菌株SAU-2为细菌素产生菌。根据形态、生理生化指标和16S rDNA序列系统发育分析,将其鉴定为Enterococcus。肠球菌SAU-2溶血素表型阴性,agg、gelE、cylM、cylB、cylA、esp、efaAfm、cpd、cob、ccf、cyILL、cyILS、fsrB和hyLEfm等毒力因子基因型阴性,表明肠球菌SAU-2是安全的。所产细菌素可耐受121℃条件20min;在pH2.0~12.0有抑菌活性;对胰蛋白酶和蛋白酶K敏感,对木瓜蛋白酶和胃蛋白酶不敏感;主要对近缘乳酸菌和G+细菌有抑菌活性,除对1株铜绿假单胞菌和1株红酵母有抑菌活性外,对其余G-细菌和真菌无抑制作用。

  18. Genome level analysis of bacteriocins of lactic acid bacteria.

    Science.gov (United States)

    Singh, Neetigyata Pratap; Tiwari, Abhay; Bansal, Ankiti; Thakur, Shruti; Sharma, Garima; Gabrani, Reema

    2015-06-01

    Bacteriocins are antimicrobial peptides which are ribosomally synthesized by mainly all bacterial species. LABs (lactic acid bacteria) are a diverse group of bacteria that include around 20 genera of various species. Though LABs have a tremendous potential for production of anti-microbial peptides, this group of bacteria is still underexplored for bacteriocins. To study the diversity among bacteriocin encoding clusters and the putative bacteriocin precursors, genome mining was performed on 20 different species of LAB not reported to be bacteriocin producers. The phylogenetic tree of gyrB, rpoB, and 16S rRNA were constructed using MEGA6 software to analyze the diversity among strains. Putative bacteriocins operons identified were found to be diverse and were further characterized on the basis of physiochemical properties and the secondary structure. The presence of at least two cysteine residues in most of the observed putative bacteriocins leads to disulphide bond formation and provide stability. Our data suggests that LABs are prolific source of low molecular weight non modified peptides.

  19. Potency Of Bacteriocin For Animal Health And Food Safety

    Directory of Open Access Journals (Sweden)

    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.

  20. Time-domain Simulations of the Acoustic Streaming Produced by a Propagating Wave Radiated by a Circular Piston

    DEFF Research Database (Denmark)

    Santillan, Arturo Orozco

    2013-01-01

    Results of numerical simulations of the sound field produced by a circular piston in a rigid baffled are presented. The aim was to calculate the acoustic streaming and the flow of mass generated by the sound field. For this purpose, the classical finite-difference time-domain method was implemented...

  1. Bacteriocins synthesized by Bacillus thuringiensis: generalities and potential applications

    OpenAIRE

    Salazar-Marroquín, Elma Laura; Galán-Wong, Luis J.; Moreno-Medina, Víctor Ricardo; Reyes-López, Miguel Ángel; Pereyra-Alférez, Benito

    2016-01-01

    The members of the Bacillus thuringiensis group, commonly known as Bt, produce a huge number of metabolites, which show biocidal and antagonistic activity. B. thuringiensis is widely known for synthesizing Cry, Vip and Cyt proteins, active against insects and other parasporins with biocidal activity against certain types of cancerous cells. Nevertheless, B. thuringiensis also synthesizes compounds with antimicrobial activity, especially bacteriocins. Some B. thuringiensis bacteriocins resembl...

  2. Antimicrobial Activity of Bacteriocins and Their Applications

    Science.gov (United States)

    Drosinos, Eleftherios H.; Mataragas, Marios; Paramithiotis, Spiros

    Bacteriocins are peptides or proteins that exert an antimicrobial action against a range of microorganisms. Their production can be related to the antagonism within a certain ecological niche, as the producer strain, being itself immune to its action, generally gains a competitive advantage. Many Gram-positive and Gram-negative microorganisms have been found to produce bacteriocins. The former, and especially the ones produced by lactic acid bacteria, has been the field of intensive research during the last decades mainly due to their properties that account for their suitability in food preservation and the benefits arising from that, and secondarily due to the broader inhibitory spectrum compared to the ones produced by Gramnegative microorganisms.

  3. 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.

  4. Bacteriocins from lactic acid bacteria and their applications in meat and meat products.

    Science.gov (United States)

    Woraprayote, Weerapong; Malila, Yuwares; Sorapukdee, Supaluk; Swetwiwathana, Adisorn; Benjakul, Soottawat; Visessanguan, Wonnop

    2016-10-01

    Meat and meat products have always been an important part of human diet, and contain valuable nutrients for growth and health. Nevertheless, they are perishable and susceptible to microbial contamination, leading to an increased health risk for consumers as well as to the economic loss in meat industry. The utilization of bacteriocins produced by lactic acid bacteria (LAB) as a natural preservative has received a considerable attention. Inoculation of bacteriocin-producing LAB cell as starter or protective cultures is suitable for fermented meats, whilst the direct addition of bacteriocin as food additive is more preferable when live cells of LAB could not produce bacteriocin in the real meat system. The incorporation of bacteriocins in packaging is another way to improve meat safety to avoid direct addition of bacteriocin to meat. Utilization of bacteriocins can effectively contribute to food safety, especially when integrated into hurdle concepts. In this review, LAB bacteriocins and their applications in meat and meat products are revisited. The molecular structure and characteristics of bacteriocins recently discovered, as well as exemplary properties are also discussed.

  5. 产细菌素乳酸菌的鉴定及其特性研究%Identification of Bacteriocin-Producing Lactobacillus and Study on Its Characteristic

    Institute of Scientific and Technical Information of China (English)

    王小娜; 宋达峰; 顾青

    2011-01-01

    Lactic acid bacteria isolated in the laboratory was identified. After eliminating some interference factors such as the organic acids, hydrogen peioxides and so on, the bacteriocin obtained from culture supernatant still remained active, and significant reduction in antimicrobial activity was observed after treatment with proteinase K and trypsin, confirming its proteinaceous nature. The bacteriocin showed high temperature stability up to 120 ℃ for 30 min with less loss in its activity, and had pH stability in the range of 2~4. The molecular weight of the bacteriocin is approximately 4.0 kDa by tricine-SDS-PAGE assay. And the bacteriocin also evidenced a broad spectrum of antibacterial activity against both Gram-negative and Gram-positive bacteria including Listeria monocytogenes, Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Salmonella enterica, Pseudomonas aeruginosa, Shigella flexneri. Lactobacillus plantarum on the base of physiological and biochemical characteristics and 16S rRNA gene sequences, named as Lactobacillus plantarum ZJ317.%从婴儿粪便中分离获得能够产生抑菌活性物质的乳酸菌,通过排除有机酸、过氧化氢的干扰试验,该菌发酵上清液仍有明显的抑菌活性;通过蛋白酶K和胰蛋白酶试验,证明该菌株产生的抑菌活性物质具有蛋白质性质,是一种细菌素.初步提纯该细菌素,其抑菌活性较适pH范围为2~4,120℃热处理30 min后仍有70%的抑菌活性.经Trcine-SDS-PAGE试验分析该细菌素分子质量为4kDa.抑菌谱测定结果表明,该细菌素不仅对革兰氏阳性菌(单增李斯特氏菌、枯草芽孢杆菌、金黄色葡萄球菌等)有抑制作用,而且还抑制革兰氏阴性菌(大肠杆菌、沙门氏菌、恶臭假单胞菌、福氏志贺氏菌等),具有广谱的抑菌作用.通过菌落形态、生理生化特性试验和16S rRNA基因序列分析,鉴定该乳酸菌为植物乳杆菌,命名为Lactobacillus plantarum ZJ317.

  6. 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...... activity was detected during the stationary growth phase. The production of bacteriocin by B. subtilis B3, B122 and B222 was dependent on the aeration conditions. Maximum production of bacteriocin was observed under reduced aeration. Specific primers were used to screen isolates B3, B122 and B222 for genes...... involved in the synthesis of the bacteriocins subtilosin A, subtilin, sublancin and ericin. Amplicons of the expected sizes were detected for iywB, sboA, sboX, albA and spaS involved in the biosynthesis of subtilosin and subtilin, respectively. The translated nucleotide sequences had 100% identity...

  7. Novel bacteriocins from lactic acid bacteria (LAB): various structures and applications.

    Science.gov (United States)

    Perez, Rodney H; Zendo, Takeshi; Sonomoto, Kenji

    2014-08-29

    Bacteriocins are heat-stable ribosomally synthesized antimicrobial peptides produced by various bacteria, including food-grade lactic acid bacteria (LAB). These antimicrobial peptides have huge potential as both food preservatives, and as next-generation antibiotics targeting the multiple-drug resistant pathogens. The increasing number of reports of new bacteriocins with unique properties indicates that there is still a lot to learn about this family of peptide antibiotics. In this review, we highlight our system of fast tracking the discovery of novel bacteriocins, belonging to different classes, and isolated from various sources. This system employs molecular mass analysis of supernatant from the candidate strain, coupled with a statistical analysis of their antimicrobial spectra that can even discriminate novel variants of known bacteriocins. This review also discusses current updates regarding the structural characterization, mode of antimicrobial action, and biosynthetic mechanisms of various novel bacteriocins. Future perspectives and potential applications of these novel bacteriocins are also discussed.

  8. 贵州铜仁产广谱抑菌作用细菌素乳酸菌的筛选及鉴定%On the Sift and Identification of the Broad-spectrum Antibacterial Bacteriocin Produced in Tongren, Guizhou

    Institute of Scientific and Technical Information of China (English)

    胡美忠; 张新卓; 刘芸

    2014-01-01

    从贵州铜仁产发酵食品中分离纯化出70余株乳酸菌,采用Agar-spot-test初筛与排除酸、过氧化氢抑制后复筛出一株能产广谱抑菌作用细菌素的乳酸菌(编号G55),经生理生化及16S rDNA鉴定可知G55为植物乳杆菌。抑菌谱实验表明,G55产生的细菌素能抑制革兰阳性菌及革兰阴性菌的生长;蛋白酶实验表明,G55产生的细菌素对胃蛋白酶、蛋白酶K敏感,对胰蛋白酶、α凝乳蛋白酶部分敏感。%More than 70 strains of lactic acid bacteria are separated and purified from the fermented foods made in Tongren, Guizhou. First, they are preliminarily sifted by means of agar-spot-test and then excluded from the inhibition of the acid and hydrogen peroxide. After a second sift, a strain of lactic acid bacteria named G55 which can produce broad-spectrum antibacterial bacteriocin is chosen from them. After the physiobiochemical experiment and the 16SrDNA identification, it is concluded that G55 is an actobacillus plantarum. According to the antibacterial spectrum experiment, it shows that the bacteriocin produced by G55 can inhibit the growth of both gram-positive bacteria and gram-negative bacteria. Meanwhile, the experiment of protease shows that the bacteriorin is sensitive to pepsin and proteinase K and is partially sensitive to trypsin andαcurd protease.

  9. 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.

  10. The Two-Peptide (Class-IIb) Bacteriocins: Genetics, Biosynthesis, Structure, and Mode of Action

    Science.gov (United States)

    Nissen-Meyer, Jon; Oppegård, Camilla; Rogne, Per; Haugen, Helen Sophie; Kristiansen, Per Eugen

    The two-peptide (class-IIb) bacteriocins consist of two different peptides, both of which are required to obtain high antimicrobial activity. These bacteriocins kill target-cells by inducing membrane-leakage and they seem to display some specificity with respect to the molecules they transfer across membranes. The genes encoding the two peptides of two-peptide bacteriocins are next to each other on the same operon. In the same or a nearby operon are genes encoding (i) the immunity protein that protects the bacteriocin-producer from its own bacteriocin, (ii) a dedicated ABC-transporter that exports the bacteriocin from cells and cleaves off the N-terminal bacteriocin leader sequence, and (iii) an accessory protein whose exact function has not been fully clarified. Some two-peptide bacteriocins appear to be produced constitutively, whereas the production of other two-peptide bacteriocins is regulated through a three-component regulatory system that consists of a peptide pheromone, a membrane-associated histidine protein kinase, and response regulators. It has recently been proposed that the two peptides of (some) two-peptide bacteriocins may form a membrane-penetrating helix-helix structure involving helix-helix interacting GxxxG-motifs present in all currently characterized two-peptide bacteriocins. It has also been suggested that the helix-helix structure interacts with an integrated membrane (transport) protein, thus inducing a conformational change in the protein, which in turn causes membrane-leakage. This proposed mode-of-action is similar to that of the pediocin-like (class-IIa) bacteriocins and lactococcin A, which bind to a part of the mannose phosphotransferase permease that is embedded in the cell membrane, thereby altering the conformation of the ­permease in a manner that causes membrane-leakage and cell death.

  11. Native and heterologous production of bacteriocins from gram-positive microorganisms.

    Science.gov (United States)

    Muñoz, Mabel; Jaramillo, Diana; Melendez, Adelina Del Pilar; J Alméciga-Diaz, Carlos; Sánchez, Oscar F

    2011-12-01

    In nature, microorganisms can present several mechanisms for setting intercommunication and defense. One of these mechanisms is related to the production of bacteriocins, which are peptides with antimicrobial activity. Bacteriocins can be found in Gram-positive and Gram-negative bacteria. Nevertheless, bacteriocins produced by Gram-positive bacteria are of particular interest due to the industrial use of several strains that belong to this group, especially lactic acid bacteria (LAB), which have the status of generally recognized as safe (GRAS) microorganisms. In this work, we will review recent tendencies in the field of invention and state of art related to bacteriocin production by Gram-positive microorganism. Hundred-eight patents related to Gram-positive bacteriocin producers have been disclosed since 1965, from which 57% are related bacteriocins derived from Lactococcus, Lactobacillus, Streptococcus, and Pediococcus strains. Surprisingly, patents regarding heterologous bacteriocins production were mainly presented just in the last decade. Although the major application of bacteriocins is concerned to food industry to control spoilage and foodborne bacteria, during the last years bacteriocin applications have been displacing to the diagnosis and treatment of cancer, and plant disease resistance and growth promotion.

  12. Sensitivity to the two-peptide bacteriocin lactococcin G is dependent on UppP, an enzyme involved in cell-wall synthesis

    NARCIS (Netherlands)

    Kjos, Morten; Oppegård, Camilla; Diep, Dzung B; Nes, Ingolf F; Veening, Jan-Willem; Nissen-Meyer, Jon; Kristensen, Tom

    2014-01-01

    Most bacterially produced antimicrobial peptides (bacteriocins) are thought to kill target cells by a receptor-mediated mechanism. However, for most bacteriocins the receptor is unknown. For instance, no target receptor has been identified for the two-peptide bacteriocins (class IIb), whose activity

  13. 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

    Aims: To investigate factors influencing bacteriocin production and bacteriocin stability of the bioprotective culture Carnobacterium piscicola strain A9b. Methods and Results: Maximum activity was obtained in MRS7 broth (MRS adjusted to pH 7.2), with or without glucose. No bacteriocin was produc....... Significance and Impact of the Study: The influence of NaCl on bacteriocin production may negate the inhibitory effect of C. piscicola A9b against Listeria monocytogenes in salty foods....

  14. 枯草芽孢杆菌MA139类细菌素抑菌活性的研究%Studies on the Antibacterial Activity of Bacteriocin-like Inhibitory Substances (BLIS) Produced from Bacillus subtilis MA139

    Institute of Scientific and Technical Information of China (English)

    胡婷; 陆文清

    2012-01-01

    为测定枯草芽孢杆菌MA139产生的类细菌素的抑菌活性.本试验采用管碟法对枯草芽孢杆菌MA139产生的类细菌素对多株革兰氏阳性菌、革兰氏阴性菌和真菌的抑菌活性进行测定.结果表明:类细菌素不但对芽孢杆菌属的其他菌种有抗菌活性,对病原菌和霉菌也有拮抗作用;不同指示菌对类细菌素的敏感性不一样,其中金黄色葡萄球菌对其最敏感.该类细菌素具有广谱抗菌作用,有作为畜禽饲料添加剂的潜力.%One experiment was conducted to determine the antibacterial activity of bacteriocin -like inhibitory substances (BLIS) produced from Bacillus subtilis MA139. The bacteriocin-like inhibitory substances were screened for antibacterial activity against indicator strains using agar spot assay. The results showed that they had broad spectrum of antagonistic activity against indicator strains, and Staphylococcus aureus showed greatest sensitivity to the BLIS. In conclusion, BOS from Bacillus subtilis MA139 had broad spectrum of antagonistic activity against various species of bacterial and fungal pathogens and could potentially be used as feed additives.

  15. Expression of linear permutated variants from circular enterocin AS-48

    NARCIS (Netherlands)

    Montalbán-López, Manuel; Martínez-Bueno, Manuel; Valdivia, Eva; Maqueda, Mercedes

    2011-01-01

    To confirm whether the head-to-tail circularization could be involved in the stability and activity of the circular bacteriocin AS-48, two permutated linear structural as-48A genes have been constructed by circular permutation. The absence of the leaderless linear AS(23/24) and AS(48/49) proteins in

  16. Spontaneous bacteriocin resistance in Listeria monocytogenes as a susceptibility screen for identifying different mechanisms of resistance and modes of action by bacteriocins of lactic acid bacteria.

    Science.gov (United States)

    Macwana, Sunita; Muriana, Peter M

    2012-01-01

    A practical system was devised for grouping bacteriocins of lactic acid bacteria (LAB) based on mode of action as determined by changes in inhibitory activity to spontaneously-acquired bacteriocin resistance (Bac(R)). Wild type Listeria monocytogenes 39-2 was sensitive to five bacteriocins produced by 3 genera of LAB: pediocin PA-1 and pediocin Bac3 (Pediococcus), lacticin FS97 and lacticin FS56 (Lactococcus), and curvaticin FS47 (Lactobacillus). A spontaneous Bac(R) derivative of L. monocytogenes 39-2 obtained by selective recovery against lacticin FS56 provided complete resistance to the bacteriocin made by Lactococcus lactis FS56. The lacticin FS56-resistant strain of L. monocyotgenes 39-2 was also cross-resistant to curvaticin FS47 and pediocin PA-1, but not to lacticin FS97 or pediocin Bac3. The same pattern of cross-resistance was also observed with Bac(R) isolates obtained with L. monocytogenes Scott A-2. A spontaneous mutation that renders a strain cross-resistant to different bacteriocins indicates that they share a common mechanism of resistance due to similar modes of action of the bacteriocins. Spontaneous resistance was acquired to other bacteriocins (in aggregate) by following the same procedure against which the Bac(R) strain was still sensitive. In subsequent challenge assays, mixtures of bacteriocins of different modes of action provided greater inhibition than mixtures of bacteriocins of the same mode of action (as determined by our screening method). This study identifies a methodical approach to classify bacteriocins into functional groups based on mechanism of resistance (i.e., mode of action) that could be used for identifying the best mixture of bacteriocins for use as biopreservatives.

  17. Production of multiple bacteriocins from a single locus by gastrointestinal strains of Lactobacillus salivarius.

    Science.gov (United States)

    O'Shea, Eileen F; O'Connor, Paula M; Raftis, Emma J; O'Toole, Paul W; Stanton, Catherine; Cotter, Paul D; Ross, R Paul; Hill, Colin

    2011-12-01

    Bacteriocins produced by Lactobacillus salivarius isolates derived from a gastrointestinal origin have previously demonstrated efficacy for in vivo protection against Listeria monocytogenes infection. In this study, comparative genomic analysis was employed to investigate the intraspecies diversity of seven L. salivarius isolates of human and porcine intestinal origin, based on the genome of the well-characterized bacteriocin-producing strain L. salivarius UCC118. This revealed a highly conserved megaplasmid-borne gene cluster in these strains involved in the regulation and secretion of two-component class IIb bacteriocins. However, considerable intraspecific variation was observed in the structural genes encoding the bacteriocin peptides. They ranged from close relatives of abp118, such as salivaricin P, which differs by 2 amino acids, to completely novel bacteriocins, such as salivaricin T, which is characterized in this study. Salivaricin T inhibits closely related lactobacilli and bears little homology to previously characterized salivaricins. Interestingly, the two peptides responsible for salivaricin T activity, SalTα and SalTβ, share considerable identity with the component peptides of thermophilin 13, a bacteriocin produced by Streptococcus thermophilus. Furthermore, the salivaricin locus of strain DPC6488 also encodes an additional novel one-component class IId anti-listerial bacteriocin, salivaricin L. These findings suggest a high level of redundancy in the bacteriocins that can be produced by intestinal L. salivarius isolates using the same enzymatic production and export machinery. Such diversity may contribute to their ability to dominate and compete within the complex microbiota of the mammalian gut.

  18. Production of Multiple Bacteriocins from a Single Locus by Gastrointestinal Strains of Lactobacillus salivarius▿

    Science.gov (United States)

    O'Shea, Eileen F.; O'Connor, Paula M.; Raftis, Emma J.; O'Toole, Paul W.; Stanton, Catherine; Cotter, Paul D.; Ross, R. Paul; Hill, Colin

    2011-01-01

    Bacteriocins produced by Lactobacillus salivarius isolates derived from a gastrointestinal origin have previously demonstrated efficacy for in vivo protection against Listeria monocytogenes infection. In this study, comparative genomic analysis was employed to investigate the intraspecies diversity of seven L. salivarius isolates of human and porcine intestinal origin, based on the genome of the well-characterized bacteriocin-producing strain L. salivarius UCC118. This revealed a highly conserved megaplasmid-borne gene cluster in these strains involved in the regulation and secretion of two-component class IIb bacteriocins. However, considerable intraspecific variation was observed in the structural genes encoding the bacteriocin peptides. They ranged from close relatives of abp118, such as salivaricin P, which differs by 2 amino acids, to completely novel bacteriocins, such as salivaricin T, which is characterized in this study. Salivaricin T inhibits closely related lactobacilli and bears little homology to previously characterized salivaricins. Interestingly, the two peptides responsible for salivaricin T activity, SalTα and SalTβ, share considerable identity with the component peptides of thermophilin 13, a bacteriocin produced by Streptococcus thermophilus. Furthermore, the salivaricin locus of strain DPC6488 also encodes an additional novel one-component class IId anti-listerial bacteriocin, salivaricin L. These findings suggest a high level of redundancy in the bacteriocins that can be produced by intestinal L. salivarius isolates using the same enzymatic production and export machinery. Such diversity may contribute to their ability to dominate and compete within the complex microbiota of the mammalian gut. PMID:21984788

  19. Harnessing bacteriocin biology as targeted therapy in the GI tract.

    Science.gov (United States)

    Kommineni, Sushma; Kristich, Christopher J; Salzman, Nita H

    2016-11-01

    Recently, our laboratory demonstrated that bacteriocins produced by commensal enterococci provide an advantage in niche maintenance in the highly competitive environment of the gastrointestinal (GI) tract. Bacterial production of bacteriocins is a conserved defense strategy to help establish an ecological niche. Bacteriocin-encoding genes in enterococci are often carried on mobile genetic elements, including conjugative plasmids, enabling the transfer of such traits to other community members in a shared niche. Use of a novel mouse model for enterococcal colonization of the GI tract allowed us to investigate enterococcal dynamics and the role of enterococcal bacteriocins in the mouse GI tract. We examined the role of bacteriocin-21, carried on the pPD1 plasmid, in enterococcal colonization of the gut. We discovered that Enterococcus faecalis (EF) harboring pPD1 effectively colonizes the GI tract by using Bac-21 to eliminate its competition. In our study, we also present evidence for active conjugation in the GI tract, a strategy EF uses to enhance the number of bacteriocin producers in a given niche and eliminate bacteriocin-susceptible populations. Using an engineered strain of EF that is capable of producing Bac-21 but impaired in its conjugation ability, we were able to reduce pre-existing colonization by vancomycin-resistant enterococci in the mouse gut. Thus, our results suggest a novel therapeutic strategy to de-colonize antibiotic-resistant enterococci from the GI tract of patients and thereby prevent the emergence of resistant enterococcal infections that are otherwise difficult, or impossible, to treat.

  20. Enterococcus faecium isolated from Lombo, a Portuguese traditional meat product: characterisation of antibacterial compounds and factors affecting bacteriocin production.

    Science.gov (United States)

    Todorov, S D; Favaro, L; Gibbs, P; Vaz-Velho, M

    2012-12-01

    Strain ST211CH, identified as a strain of Enterococcus faecium, isolated from Lombo produced a bacteriocin that inhibited the growth of Enterococcus spp., Listeria spp., Klebsiella spp., Lactobacillus spp., Pseudomonas spp., Staphylococcus spp. and Streptococcus spp. The mode of action of the bacteriocin named as bacteriocin ST211Ch was bactericidal against Enterococcus faecalis ATCC19443. As determined by Tricine-SDS-PAGE, the approximate molecular mass of the bacteriocin was 8.0 kDa. Loss in antimicrobial activity was recorded after treatment with proteolytic enzymes. Maximum activity of bacteriocin ST211Ch was measured in broth cultures of E. faecium strain ST211Ch after 24 h; thereafter, the activity was reduced. Bacteriocin ST211Ch remained active after exposure to various temperatures and pHs, as well as to Triton X-100, Tween-80, Tween-20, sodium dodecyl sulfate, NaCl, urea and EDTA. Effect of media components on production of bacteriocin ST211Ch was also studied. On the basis of PCR reactions targeting different bacteriocin genes, i.e. enterocins, curvacins and sakacins, no evidences for the presence of these genes in the total DNA of E. faecium strain ST211Ch was obtained. The bacterium most probably produced a bacteriocin different from those mentioned above. Based on the antimicrobial spectrum, stability and mode of action of bacteriocin ST211CH, E. faecium strain ST211Ch might be considered as a potential candidate with beneficial properties for use in biopreservation to control food spoilage bacteria.

  1. Perspective rectification of integral images produced using arrays of circular lenses.

    Science.gov (United States)

    Koufogiannis, E T; Sgouros, N P; Sangriotis, M S

    2013-07-10

    There are many different three-dimensional (3D) techniques to capture and deliver autostereoscopic 3D content. A promising technique that provides two-dimensional parallax as well as high-quality, full-color 3D content is integral imaging (InI). Misalignments between the lens arrays (LAs) and the camera charged coupled device, however, introduce geometric distortions in the acquired image that propagate through the different image processing stages and deteriorate the 3D effect. Here, we propose a method to accurately rectify the perspective distortion of integral images (InIms) generated using circular lenses. Using an edge-linking approach, we extracted elliptically shaped contours of elemental images in the perspectively distorted InIm. To calculate the rectification matrix, we used the images of the circular points. Subsequently, we applied a triangulation scheme followed by a statistical approach to accurately estimate the grid structure of the LA. Finally, we provided experimental results over a wide range of InIms to evaluate the robustness and accuracy of the proposed method using objective metrics.

  2. Bacteriocin-Mediated Competitive Interactions of Bacterial Populations and Communities

    Science.gov (United States)

    Riley, Margaret A.

    Explaining the coexistence of competing species is a major challenge in community ecology. In bacterial systems, competition is often driven by the production of bacteriocins; narrow spectrum proteinaceous toxins that serve to kill closely related species providing the producer better access to limited resources. Bacteriocin producers have been shown to competitively exclude sensitive, nonproducing strains. However, the interaction dynamics between bacteriocin producers, each lethal to its competitor, are largely unknown. Several recent studies have revealed some of the complexity of these interactions, employing a suite of in vitro, in vivo, and in silico bacterial model systems. This chapter describes the current state of knowledge regarding the population and community ecology of this potent family of toxins.

  3. Bacteriocins from Gram-Negative Bacteria: A Classification?

    Science.gov (United States)

    Rebuffat, Sylvie

    Bacteria produce an arsenal of toxic peptides and proteins, which are termed bacteriocins and play a role in mediating the dynamics of microbial populations and communities. Bacteriocins from Gram-negative bacteria arise mainly from Enterobacteriaceae. They assemble into two main families: high molecular mass modular proteins (30-80 kDa) termed colicins and low molecular mass peptides (between 1 and 10 kDa) termed microcins. The production of colicins is mediated by the SOS response regulon, which plays a role in the response of many bacteria to DNA damages. Microcins are highly stable hydrophobic peptides that are produced under stress conditions, particularly nutrient depletion. Colicins and microcins are found essentially in Escherichia coli, but several other Gram-negative species also produce bacteriocin-like substances. This chapter presents the basis of a classification of colicins and microcins.

  4. Isolation and Identification of Bacteriocin-producing Lactic Acid Bacteria from Meat Production%肉制品中产细菌素乳酸菌的分离及鉴定

    Institute of Scientific and Technical Information of China (English)

    刘丽; 郝彦玲; 张红星; 谢英

    2011-01-01

    从北京市售肉制品中分离筛选出1株具有抑菌活性的乳酸茵菌株L5-6,对单核细胞增生李斯特氏菌ATCC54003的生长具有良好的抑制作用.排除有机酸、过氧化氢的干扰后,确定该抑茵物质为蛋白类物质,即细菌素.16S rRNA序列同源性分析鉴定L5-6为戊糖片球菌.对L5-6中编码细菌素的结构基因进行克隆,推断L5-6所产的细茵素是片球菌素.片球菌素应用于肉制品防腐具有潜在的开发价值和广阔的市场前景,课题组对L5-6进行了初步的研究,为开发天然安全的食品保鲜防腐剂奠定基础.%Strain L5-6, isolated from meat production in Beijing, produced antimicrobial substance which was inhibitory to Listeria monocytogenes 54003. After eliminating the effect of organic acid and hydrogen peroxide,the antimicrobial substance with its proteinaceous nature was confirmed as bacteriocin. And also strain L5-6 was identified as Pediococcus pentosaceus by using 16S rRNA gene sequence homology analysis. Pediocin shows potential developing value and broad market prospect, especially in the meat products. The bacteriocin produced by L5-6 was identified as pediocin after cloning its structural gene. In this paper a preliminary study on L5-6 had been made to lay the basis for the development of natural food preservative.

  5. 产细菌素植物乳杆菌纯种半固态发酵对泡菜品质的影响%Effect of Lactobacillus plantarum producing bacteriocine on pickle quality in semi-solid-state fermentation

    Institute of Scientific and Technical Information of China (English)

    韩新锋; 刘书亮; 张艾青; 杜晓华

    2012-01-01

    以产细菌素植物乳杆菌纯种半固态发酵制作什锦泡菜,同时以其纯种液态发酵泡菜和传统自然发酵泡菜为对照,比较三种泡菜在发酵过程和贮藏期间感官、理化指标与微生物菌相变化规律,评价半固态发酵对泡菜品质的影响.结果表明,该菌株纯种发酵制作的泡菜感官品质优于自然发酵泡菜,细菌、酵母菌、霉菌、大肠菌群数量均显著低于自然发酵泡菜;其中,纯种半固态发酵泡菜发酵过程pH值下降最迅速、泡菜中乳酸菌活菌数量高(108cfu/g)、亚硝酸盐含量低且无明显“亚硝峰”出现;说明产细菌素植物乳杆菌纯种半固态发酵制作什锦泡菜品质优于纯种液态发酵和自然发酵泡菜.%Mixed pickles were prepared by Lactobacillus plantarum producing bacteriocine with semi-solid fermentation; meanwhile pickles prepared by pure liquid fermentation and traditional natural fermentation were set as controls. Oranoleptic indicator, physical and chemical indicator, microorganism changes were compared during fermentation and storage to evaluate the effect of semi-solid fermentation. The results showed that the oranoleptic indicator of the pickles with pure semi-solid fermentation was superior to those with natural fermentation; the numbers of total plate counts, yeasts, moulds, coliform group were significantly lower than those of natural fermentation, respectively. The pH value of the pickles prepared by semi-solid fermentation decreased quickly, the numbers of viable lactic acid bacteria in the pickles with semi-solid fermentation were 108cfu/g, and the nitrites contents were low which had no obvious nitrites peak. The results indicated that the mixed pickles prepared by L. plantarum producing bacteriocine with pure semi-solid fermentation had a high quality among three kinds of fermentation.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    Sousa, Mireille Ângela Bernardes; Farias, Luiz de Macêdo; Oliveira, Patrícia Luciana de; Moreira, Jaqueline Silvana; Apolônio, Ana Carolina Morais; Oliveira, Jamil Silvano; Santoro, Marcelo Matos; Mendes, Edilberto Nogueira; Magalhães, Paula Prazeres

    2013-09-01

    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.

  8. Screening and Identification of Bacteriocin-like Substance Producing Bacillus%一株产细菌素物质芽孢杆菌的筛选和鉴定

    Institute of Scientific and Technical Information of China (English)

    李俊峰; 李红芳; 段孝辉; 宿烽; 田智刚

    2011-01-01

    One Bacillus strain named SLY—3 producing bacteriocin-like substance ( BLS) was screened from the soil polluted by oil. The G +bacteria and molds were effectively inhibited by BLS produced by strain SLY—3. With the analysis of colony morphology, physiological and biochemistry experiments and 16S rDNA gene sequence, the strain SLY—3 was identified as Bacillus subtilis. The BLS secreted by Bacillus subtilis SLY—3 has the highest inhibitory activity when it is cultured for 24 h at initial pH 7.0 and 28 ℃ .%从石油污染的土壤中筛选出一株能产生细菌素类物质的芽孢杆菌,命名为SLY-3.该菌株分泌的活性物质抑菌活性好,对细菌主要是革兰氏阳性菌、霉菌都有抑制作用.从表型、生理生化反应及16S rDNA序列比对方面进行分析,最终确定菌株SLY-3 为枯草芽孢杆菌(Bacillus subtilis).培养基初始pH为7.0,28℃振荡培养24 h后,发酵产物抑菌活性最高.

  9. 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 infections. We

  10. 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 proteinaceo

  11. 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...

  12. 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...

  13. 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

  14. 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 proteinaceo

  15. Lantibiotics, class I bacteriocins from the genus Bacillus.

    Science.gov (United States)

    Lee, Hyungjae; Kim, Hae-Yeong

    2011-03-01

    Antimicrobial peptides exhibit high levels of antimicrobial activity against a broad range of spoilage and pathogenic microorganisms. Compared with bacteriocins produced by lactic acid bacteria, antimicrobial peptides from the genus Bacillus have been relatively less recognized despite their broad antimicrobial spectra. These peptides can be classified into two different groups based on whether they are ribosomally (bacteriocins) or nonribosomally (polymyxins and iturins) synthesized. Because of their broad spectra and high activity, antimicrobial peptides from Bacillus spp. may have great potential for applications in the food, agricultural, and pharmaceutical industries to prevent or control spoilage and pathogenic microorganisms. In this review, we introduce ribosomally synthesized antimicrobial peptides, the lantibiotic bacteriocins produced by members of Bacillus. In addition, the biosynthesis, genetic organization, mode of action, and regulation of subtilin, a well-investigated lantibiotic from Bacillus subtilis, are discussed.

  16. Target recognition, resistance, immunity and genome mining of class II bacteriocins from Gram-positive bacteria.

    Science.gov (United States)

    Kjos, Morten; Borrero, Juan; Opsata, Mona; Birri, Dagim J; Holo, Helge; Cintas, Luis M; Snipen, Lars; Hernández, Pablo E; Nes, Ingolf F; Diep, Dzung B

    2011-12-01

    Due to their very potent antimicrobial activity against diverse food-spoiling bacteria and pathogens and their favourable biochemical properties, peptide bacteriocins from Gram-positive bacteria have long been considered promising for applications in food preservation or medical treatment. To take advantage of bacteriocins in different applications, it is crucial to have detailed knowledge on the molecular mechanisms by which these peptides recognize and kill target cells, how producer cells protect themselves from their own bacteriocin (self-immunity) and how target cells may develop resistance. In this review we discuss some important recent progress in these areas for the non-lantibiotic (class II) bacteriocins. We also discuss some examples of how the current wealth of genome sequences provides an invaluable source in the search for novel class II bacteriocins.

  17. Bacteriocins and their position in the next wave of conventional antibiotics.

    Science.gov (United States)

    Cavera, Veronica L; Arthur, Timothy D; Kashtanov, Dimitri; Chikindas, Michael L

    2015-11-01

    Micro-organisms are capable of producing a range of defence mechanisms, including antibiotics, bacteriocins, lytic agents, protein exotoxins, etc. Such mechanisms have been identified in nearly 99% of studied bacteria. The multiplicity and diversity of bacteriocins and the resultant effects of their interactions with targeted bacteria on microbial ecology has been thoroughly studied and remains an area of investigation attracting many researchers. However, the incorporation of bacteriocins into drug delivery systems used in conjunction with, or as potential alternatives to, conventional antibiotics is only a recent, although rapidly expanding, field. The extensive array of bacteriocins positions them as one of the most promising options in the next wave of antibiotics. The goal of this review was to explore bacteriocins as novel antimicrobials, alone and in combination with established antibiotics, and thus position them as a potential tool for addressing the current antibiotic crisis.

  18. 产细菌素乳酸菌的选育及其抑菌特性的研究%Screening of bacteriocin-producing lactic acid bacteria and the characteristics of antibacterial compound

    Institute of Scientific and Technical Information of China (English)

    吴荣荣; 张良; 王倩

    2009-01-01

    采用牛津杯琼脂扩散法,从实验室保存的乳酸菌中筛选到具有较高抑菌活性的菌株嗜酸乳杆菌A、戊糖片球菌M和戊糖片球菌T,它们产生的抑菌物质经排除酸、过氧化氢后,仍具有抑菌活性,然而经蛋白酶处理后其抑菌活性明显下降,确定其抑菌物质为细菌素,进一步的抑菌实验表明,3株菌所产细菌素具有较宽的抑菌谱,适宜用作生物型防腐剂.%Three strains, which showed obvious antibacterial activity, were isolated from lactic acid bacteria, including Lactobacillus.Acidophilus (A), Pediococcus pentosaceus(M)and Pediococcus pentosaceus(T)by the agar diffusion cup-plate method.The supernatants after eliminated organic acid and hydrogen peroxide still retained bacteriostatic activity.The effect of inhibition decreased after treatment with protease K, The above results indicated that the antibacterial substance was a kind of protein.The inhibitory spectrum from the above supernatants was broad.The bacteriocin produced by three strains was suitable for the biotype preservatives.

  19. Enhancing the antilisterial effect of Lactobacillus curvatus CWBI-B28 in pork meat and cocultures by limiting bacteriocin degradation.

    Science.gov (United States)

    Kouakou, Privat; Ghalfi, Hakim; Destain, Jacqueline; Duboisdauphin, Robin; Evrard, Pol; Thonart, Philippe

    2008-11-01

    This work focused on Listeria monocytogenes growth inhibition and growth rebound in raw and cooked pork meat inoculated with Lactobacillus curvatus strains. During storage of raw meat homogenates in the presence of the bacteriocin-producing strain Lactobacillus curvatus CWBI-B28wt, the Listeria monocytogenes cfu count was initially reduced to an undetectable level, but a growth rebound occurred after two weeks, coinciding with loss of 70% of the bacteriocin activity present at the end of week 2. The Listeria growth rebound was suppressed when proteolysis of bacteriocin was countered by the absence of proteases (bacteriocin addition to cooked meat) or the presence of 1% soy flour (added to provide competing substrates). Further experiments confirmed that bacteriocin is sensitive to the action of proteolytic enzymes isolated from both Lactobacillus curvatus CWBI-B28wt and the meat matrix. Bacteriocin proteolysis thus emerges as a cause of Listeria growth rebound.

  20. Bacteriocins as potential anticancer agents

    Directory of Open Access Journals (Sweden)

    Sukhraj eKaur

    2015-11-01

    Full Text Available Cancer remains one of the leading causes of deaths worldwide, despite advances in its treatment and detection. The conventional chemotherapeutic agents used for the treatment of cancer have nonspecific toxicity towards normal body cells that cause various side effects. Secondly, cancer cells are known to develop chemotherapy resistance in due course of treatment. Thus, the demand for novel anti-cancer agents is increasing day by day. Some of the experimental studies have reported the therapeutic potential of bacteriocins against various types of cancer cell lines. Bacteriocins are ribosomally-synthesized cationic peptides secreted by almost all groups of bacteria. Some bacteriocins have shown selective cytotoxicity towards cancer cells as compared to normal cells. This makes them promising candidates for further investigation and clinical trials. In this review article, we present the overview of the various cancer cell-specific cytotoxic bacteriocins, their mode of action and efficacies.

  1. Bacteriocins as Potential Anticancer Agents

    National Research Council Canada - National Science Library

    Kaur, Sumanpreet; Kaur, Sukhraj

    2015-01-01

    .... Thus, the demand for novel anti-cancer agents is increasing day by day. Some of the experimental studies have reported the therapeutic potential of bacteriocins against various types of cancer cell lines...

  2. 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

  3. Effect of the fermentation broth of a bacteriocin-producing lactobacillus plantarum YJG on the production performance and egg quality of laying hens%一株产细菌素植物乳酸杆菌YJG发酵液对蛋鸡生产性能以及蛋品质的影响

    Institute of Scientific and Technical Information of China (English)

    韩冰; 邓凯; 张日俊

    2011-01-01

    To study effect of the fermentation broth of a bacteriocin-producing Lactobacillus plantarum YJG on production performance and egg quality of laying hens. Two hundred and twenty five laying hens of 232-day-old were randomly divided into 5 treatment groups with 5 replicates, and the trials period was 34 days. The results showed that treatment with 500 AU/kg bacteriocin could enhance the average weight, and the treatments with bacteriocins could apparently reduce the feed egg ratio(P<0.05), Bacteriocins produced by Lactobacillus plantarum YJG could improve the production performance and egg quality of laying hens and provide new insight into research of feed additives.%研究一株植物乳酸杆菌细菌素对蛋鸡生产性能和蛋品质的影响.选用232日龄产蛋率和体重相近、健康状况良好的海兰灰蛋鸡225只,试验期为34 d.结果表明:日粮中添加500 AU/kg植物乳酸杆菌细菌素对蛋鸡的产蛋率和平均蛋重的提升幅度最大,各细菌素添加组对降低料蛋比均有显著的效果(P<0.05),对平均日采食量、蛋黄色泽、哈氏单位、蛋壳强度和蛋形指数都有不同程度的改善.植物乳酸杆菌细菌素可以明显改善蛋鸡生产性能和蛋品质,可以为饲料添加剂的研发提供新的思路.

  4. Lactobacillus farciminis MD, a newer strain with potential for bacteriocin and antibiotic assay.

    Science.gov (United States)

    Halami, P M; Chandrashekar, A; Nand, K

    2000-03-01

    A native isolate Lactobacillus farciminis MD isolated from fermenting mushroom exhibited a high degree of sensitivity to the majority of the bacteriocins produced by strains of lactobacilli, leuconostoc and pediococci. Also, the efficacy of Lact. farciminis MD as a sensitive strain for antibiotic assay was established against different antibiotics including ampicillin, cefazoline, chloramphenicol and nitrofurantoin at concentrations of 30 microg each, showing an inhibition zone of 30 mm diameter. The high degree of sensitivity towards bacteriocins and antibiotics provide potential for the exploitation of Lact. farciminis MD in establishing very well-defined bacteriocin producers.

  5. Characteristic of bacteriocines and their application

    National Research Council Canada - National Science Library

    Karpiński, Tomasz M; Szkaradkiewicz, Anna K

    2013-01-01

    .... Until now, a few hundred bacteriocines were described. Classification of bacteriocines undergoes continuous alterations, as new developments regarding their structure, amino acid sequence and recognised mechanism of their action are available...

  6. A Study of the use of a Crystal as a `Quarter-Wave Plate' to Produce High Energy Circularly Polarized Photons

    CERN Multimedia

    Kononets, I

    2002-01-01

    %NA59 %title\\\\ \\\\We present a proposal to study the use of a crystal as a `quarter-wave plate' to produce high energy circularly polarized photons, starting from unpolarized electrons. The intention is to generate linearly polarized photons by letting electrons pass a crystalline target, where they interact coherently with the lattice nuclei. The photon polarization is subsequently turned into circular polarization after passing another crystal, which acts as a `quarter-wave plate'.

  7. 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 produ

  8. Persistence of the Oral Probiotic Streptococcus salivarius M18 Is Dose Dependent and Megaplasmid Transfer Can Augment Their Bacteriocin Production and Adhesion Characteristics: e65991

    National Research Council Canada - National Science Library

    Jeremy P Burton; Philip A Wescombe; Jean M Macklaim; Melissa H C Chai; Kyle MacDonald; John D F Hale; John Tagg; Gregor Reid; Gregory B Gloor; Peter A Cadieux

    2013-01-01

      Bacteriocin-producing probiotic Streptococcus salivarius M18 offers beneficial modulatory capabilities within the oral microbiome, apparently through potent inhibitory activity against potentially...

  9. Isolation of Lactobacillus salivarius from Children and Purification of Bacteriocin to Inhibition Cancer Cell in Vitro

    Directory of Open Access Journals (Sweden)

    Waleed K. M. Al-Tememy

    2011-01-01

    Full Text Available Bacteria being used to make anticancer agents could provide an extra source of lead compounds for the pharmaceutical industry.  Bacterium Lactobacillus salivarius produce compounds that selectively inhibit growth of human cancer cells Lactobacillus salivarius naturally produces a compound called Bacteriocins.  Bacteriocins are bacterial proteins produced to prevent the growth of competing microorganisms in a particular biological niche and we can use it as antineoplastic. The aim of this study was to isolate bacteriocin produced by lactic acid bacteria. A preparation of bacteriocin from a strain Lactobacillus salivarius has long been shown to have antineoplastic activity against a variety of human tumor and animal tumor cell lines in vitro. A total of 60 LAB  were isolated from children stool 45 isolate showed a clear antimicrobial activity against indicator strain Streptococcus aureus and by used sodium phosphate buffer (pH8 from an 80% ammonium sulfate precipitate. The inhibition  activity was determent by well diffusion assay method technique, Bacteriocin purification processes were carried out by using ion-exchange (Trisacryl SP and gel filtration chromatography (Sephacryl – S300. The apparent molecular mass of partially purified bacteriocin was 15. 848 kDa,  Cell Culture was maintained in RPMI 1640 medium supplemented with 10% (vol/vol fetal calf serum,  Cytotoxicity of bacteriocin was assessed on human cell line (RD and animal cell line (MDCK cell viability after incubation for 48 h in medium containing 500AU/ml (1.15 mg/ml. Both cell types used in this study were sensitive to bacteriocin and the bacteriocin appeared to inhibit proliferation of tumor cell line. The animal cell line was more sensitivity than human cell line.

  10. CHARACTERIZATION OF BACTERIOCIN FROM PROBIOTIC LACTOBACILLUS PLANTARUM

    Directory of Open Access Journals (Sweden)

    A. Jayachitra*, C.M. Sukanya and N. Krithiga

    2012-11-01

    Full Text Available In our study, the sample (cheese was selected for isolation and identification of Lactobacillus species as local probiotic isolate. The strain was subjected to microscopic and macroscopic investigations for probiotic selection. The world health organization criteria (WHO were applied to all Lactobacillus species against E. coli, P. areoginosa, S. aerus, Chromobacterium, Serratia and A. flavus, antibiotic sensitivity test, acid and bile tolerance test, heamolytic activity. Antimicrobial compound called bacteriocin was partially purified. The Lactobacillus species was identified by 16S rRNA gene sequencing and specific catalase gene was also amplified. Data showed that Lactobacillus plantarum has a high inhibitory activity, tolerant to bile and acid, highly resistant to many antibiotics. Antimicrobial peptide was partially purified, characterized and bacteriocin produced by L. plantarum remained constant activity after heating at 121oC for 10 min. L. plantarum may be an alternative and promising way for eradicating many diseases. L. plantarum produces antimicrobial metabolites can give reasonable assurance of the control of pathogenic microorganisms. Increase the number of food-poisoning patients, the inhibition of the bacterial growth or production of enterotoxin such as verotoxins by administrating Lactobacilli bacteriocins would be of great importance. Lactobacillus fulfills the basic criteria required for probiotic strains which survive in in-vitro condition. The experimental strain exhibited strong antibacterial and antifungal activities against the pathogens. L. plantarum has high probiotic potential for eradicating many diseases, mainly the suppression of A. flavus which produce Aflatoxin. Pharmaceutical and nutritional industries are exploring more natural treatments for health conscious consumers as natural treatments have been effective.

  11. Histopathological studies on the effect of bacteriocin producing Bacillus cereus isolate from ‘wara’ a local soft cheese on the liver, kidney and reproductive organs of Wistar albino rats

    Directory of Open Access Journals (Sweden)

    Anyanwu, C.

    2013-01-01

    Full Text Available Aims: This study was done to generate a baseline data on the effect of Bacillus cereus and its bacteriocin on the liver, kidney and reproductive organs in both sexes at different concentration.Methodology and results: B. cereus and its bacteriocin were injected intramuscularly in male and female Wistar rats at doses equivalent to 102 CFU and 104 CFU dilutions. Body weights were also noted. The liver, kidney and reproductive organs of the animals were examined for histopathological changes. The liver of female rats administered B. cereus at 102 CFU showed portal and cellular infiltration by mononuclear cells, diffuse hydropic degeneration and severe interstitial hemorrhages of the kidney was observed when 104 CFU of B. cereus was given. Male rats administered 102 CFU and 104 CFU of B. cereus showed diffuse hydropic degeneration and portal congestion of the liver while at 104 CFU the kidney showed diffuse, moderate interstitial cellular infiltration. This is more evident in the wistar rats administered with bacilli organism than the groups that received the bacteriocin. The reproductive organs of treated animals showed no pathological lesions. There were no visible tissue pathological changes in the untreated groups. There were no visible tissue pathological changes in the untreated groups.Conclusion, significance and impact study: The absence of observable toxic effects of the bacteriocin of B. cereus on the sex organs, is not sufficient to determine the safety of this bacteriocin since pathological lesions were observed in the liver and kidney. We hereby suggest a further study on characterization and purification of this bacteriocin as a biopreservative in items not meant for human use or consumption.

  12. Antilisterial Activity of Bacteriocin Isolated from Leuconostoc mesenteroides ssp. mesenteroides IMAU:10231 in the Production of Sremska Sausages: Lactic Acid Bacteria Isolation, Bacteriocin Identification and Meat Application Experiments

    Directory of Open Access Journals (Sweden)

    Marija Škrinjar

    2013-01-01

    Full Text Available Lactic acid bacteria (LAB have an essential role in the production of fermented meat products. The metabolic activity of LAB affects the ripening process, leading to the formation of the desired sensory characteristics of the products, while inhibiting the growth of undesirable microorganisms. Bacteriocins are extracellular peptides or protein molecules, produced by some LAB, which possess bactericidal properties against specific species or genera of microorganisms, usually related bacteria. Bacteriocin production by LAB can act in a selective and competitive way against the surrounding microbiota, which may contain spoilage bacteria or pathogenic microorganisms including Listeria monocytogenes. This pathogen is widely distributed in raw products, it survives in different production areas, and human infections have a high mortality rate, all of which makes the control of this microorganism important in food production. The aim of this work is to determine the possibilities of utilizing a novel bacteriocin isolated from Leuconostoc mesenteroides ssp. mesenteroides IMAU:10231 in order to prevent the survival of Listeria monocytogenes in the production of traditional Serbian Sremska sausages. The bacteriocin-producing strain of Leuconostoc originated from the same sausage, which had been produced in the traditional manner. Bacteriocin was isolated using precipitation procedures with ammonium sulphate, and then its properties (strength and range of activities, relationship to high temperatures and proteolytic enzymes were determined under laboratory conditions. Also, based on the obtained laboratory results, the antilisterial effect of bacteriocin, included as an additive, was examined in the production of traditional Sremska sausages. Expressed antilisterial activity of bacteriocin has an interesting food safety potential which can be used in the meat industry in the production of fermented sausages. Further research will contribute to a better

  13. Prevalence, development, and molecular mechanisms of bacteriocin resistance in Campylobacter.

    Science.gov (United States)

    Bacteriocins (BCNs) are antimicrobial peptides produced by lactic acid bacteria (LAB) with narrow or broad spectra of antimicrobial activity. Recently, several unique anti-Campylobacter BCNs have been identified from commensal LAB isolated from chicken intestines. These BCNs dramatically reduced C. ...

  14. BAGEL : a web-based bacteriocin genome mining tool

    NARCIS (Netherlands)

    de Jong, Anne; van Hijum, Sacha A. F. T.; Bijlsma, Jetta J. E.; Kok, Jan; Kuipers, Oscar P.

    2006-01-01

    A common problem in the annotation of open reading frames (ORFs) is the identification of genes that are functionally similar but have limited or no sequence homology. This is particularly the case for bacteriocins, a very diverse group of antimicrobial peptides produced by bacteria and usually enco

  15. BAGEL: a web-based bacteriocin genome mining tool

    NARCIS (Netherlands)

    de Jong, A; van Hijum, S.A F T; Bijlsma, Jetta; Kok, J.; Kuipers, O.P.

    2006-01-01

    A common problem in the annotation of open reading frames (ORFs) is the identification of genes that are functionally similar but have limited or no sequence homology. This is particularly the case for bacteriocins, a very diverse group of antimicrobial peptides produced by bacteria and usually enco

  16. BAGEL : a web-based bacteriocin genome mining tool

    NARCIS (Netherlands)

    de Jong, Anne; van Hijum, Sacha A. F. T.; Bijlsma, Jetta J. E.; Kok, Jan; Kuipers, Oscar P.

    2006-01-01

    A common problem in the annotation of open reading frames (ORFs) is the identification of genes that are functionally similar but have limited or no sequence homology. This is particularly the case for bacteriocins, a very diverse group of antimicrobial peptides produced by bacteria and usually

  17. Nisin and class IIa bacteriocin resistance among Listeria and other foodborne pathogens and spoilage bacteria.

    Science.gov (United States)

    Kaur, Gurpreet; Malik, Ravinder Kumar; Mishra, Santosh Kumar; Singh, Tejinder Pal; Bhardwaj, Arun; Singroha, Garima; Vij, Shilpa; Kumar, Naresh

    2011-06-01

    Food safety has been an important issue globally due to increasing foodborne diseases and change in food habits. To inactivate foodborne pathogens, various novel technologies such as biopreservation systems have been studied. Bacteriocins are ribosomally synthesized peptides or proteins with antimicrobial activity produced by different groups of bacteria, but the bacteriocins produced by many lactic acid bacteria offer potential applications in food preservation. The use of bacteriocins in the food industry can help reduce the addition of chemical preservatives as well as the intensity of heat treatments, resulting in foods that are more naturally preserved. However, the development of highly tolerant and/or resistant strains may decrease the efficiency of bacteriocins as biopreservatives. Several mechanisms of bacteriocin resistance development have been proposed among various foodborne pathogens. The acquiring of resistance to bacteriocins can significantly affect physiological activity profile of bacteria, alter cell-envelope lipid composition, and also modify the antibiotic susceptibility/resistance profile of bacteria. This article presents a brief review on the scientific research about the various possible mechanisms involved in the development of resistance to nisin and Class IIa bacteriocins among the foodborne pathogens.

  18. 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.

  19. 产细菌素屎肠球菌E6的特性分析及发酵条件优化%Characteristics and optimization of fermentative condition for bacteriocin producing Enterococcus Faecium E6

    Institute of Scientific and Technical Information of China (English)

    饶瑜; 常伟; 唐洁; 李明元

    2013-01-01

    研究了屎肠球菌E6抑菌活性的生物学特性,并通过响应面法优化其发酵条件.结果表明,屎肠球菌E6产蛋白质类细菌素,能够抑制单增李斯特氏菌、大肠杆菌、金黄色葡萄球菌和枯草芽孢杆菌生长,在pH3.0~7.0条件下有明显抑菌活性,60~121℃热处理20min后仍具有抑菌活性.通过Box-Behnken实验设计优化屎肠球菌E6发酵条件为培养时间36.0h,培养温度31.0℃,培养基pH5.1.在此条件下,发酵上清液抑菌圈直径可达20.17mm,较优化前提高了27.2%.%The characteristics of antimicrobial activity and the fermentative condition of Enterococcus Faecium E6 were discussed.Proteinic bacteriocin produced by E6 showed inhibitory activity against Listeria monocytogenes, Escherichia coli, Staphylococcus aureus and Bacillus subtilis. It showed obviously activity under pH3.0 ~ 7.0 condition.lt was also active when heated at 60~121℃ for 20min. The fermentative condition, optimized by Box-Behnken design,was cultured at pH 5.1,temperature of 31.0℃ for 36.0h.Under this condition,the diameter of inhibition zone reached up to 20.17mm,which increased by 27.2% than optimization before.

  20. The effect of ingestion of milk supplemented with salivaricin A-producing Streptococcus salivarius on the bacteriocin-like inhibitory activity of streptococcal populations on the tongue.

    Science.gov (United States)

    Dierksen, Karen P; Moore, Chris J; Inglis, Megan; Wescombe, Philip A; Tagg, John R

    2007-03-01

    The colonization efficacies of salivaricin A (SalA)-producing Streptococcus salivarius strains 20P3 and 5 were compared when given in milk to 219 children, using either 2-day or 9-day dosing regimens. Colonization levels overall were superior for strain 5, and the 9-day dosing schedule resulted in higher levels of both initial colonization and strain persistence. The indigenous streptococcal tongue populations of 20 (10.9%) of the 189 children in the 2-day trial showed markedly increased SalA-like inhibitory activity following use of the S. salivarius-supplemented milk. All 20 of these children were found to have had relatively small (salivarius) indigenous tongue populations of SalA-producing S. salivarius, and the relative proportions and/or inhibitory activity of these SalA producers on the childrens' tongues increased following ingestion of the S. salivarius-supplemented milk. Because SalA is known to be strongly inhibitory to Streptococcus pyogenes, an important implication of this study is that the consumption of SalA-producing probiotic S. salivarius could potentially help to effect a sustained increase in SalA-mediated protection against S. pyogenes infection.

  1. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  3. 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.

  4. Streptococcal bacteriocins and the case for Streptococcus salivarius as model oral probiotics.

    Science.gov (United States)

    Wescombe, Philip A; Heng, Nicholas C K; Burton, Jeremy P; Chilcott, Chris N; Tagg, John R

    2009-09-01

    Members of the Gram-positive bacterial genus Streptococcus are a diverse collection of species inhabiting many body sites and range from benign, nonpathogenic species to those causing life-threatening infections. The streptococci are also prolific producers of bacteriocins, which are ribosomally synthesized proteinaceous antibiotics that kill or inhibit species closely related to the producer bacterium. With the emergence of bacterial resistance to conventional antibiotics, there is an impetus to discover, and implement, new and preferably 'natural' antibiotics to treat or prevent bacterial infections, a niche that bacterial interference therapy mediated by bacteriocins could easily fill. This review focuses on describing the diversity of bacteriocins produced by streptococci and also puts forth a case for Streptococcus salivarius, a nonpathogenic and numerically predominant oral species, as an ideal candidate for development as the model probiotic for the oral cavity. S. salivarius is a safe species that not only produces broad-spectrum bacteriocins but harbors bacteriocin-encoding (and bacteriocin-inducing) transmissible DNA entities (megaplasmids).

  5. Cloning of Two Bacteriocin Genes from a Lactococcal Bacteriocin Plasmid

    NARCIS (Netherlands)

    Belkum, Marco J. van; Hayema, Bert Jan; Geis, Arnold; Kok, Jan; Venema, Gerard

    1989-01-01

    Lactococcus lactis subsp. cremoris 9B4 plasmid p9B4-6 (60 kilobases [kb]), which specifies bacteriocin production and immunity, was analyzed with restriction endonucleases, and fragments of this plasmid were cloned into shuttle vectors based on the broad-host-range plasmid pWVO1. Two regions on p9B4

  6. Interactions between Oral Bacteria: Inhibition of Streptococcus mutans Bacteriocin Production by Streptococcus gordonii

    OpenAIRE

    Wang, Bing-Yan; Kuramitsu, Howard K.

    2005-01-01

    Streptococcus mutans has been recognized as an important etiological agent in human dental caries. Some strains of S. mutans also produce bacteriocins. In this study, we sought to demonstrate that bacteriocin production by S. mutans strains GS5 and BM71 was mediated by quorum sensing, which is dependent on a competence-stimulating peptide (CSP) signaling system encoded by the com genes. We also demonstrated that interactions with some other oral streptococci interfered with S. mutans bacterio...

  7. 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

  8. 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.

  9. Bacteriocins from lactic acid bacteria: production, purification, and food applications.

    Science.gov (United States)

    De Vuyst, Luc; Leroy, Frédéric

    2007-01-01

    In fermented foods, lactic acid bacteria (LAB) display numerous antimicrobial activities. This is mainly due to the production of organic acids, but also of other compounds, such as bacteriocins and antifungal peptides. Several bacteriocins with industrial potential have been purified and characterized. The kinetics of bacteriocin production by LAB in relation to process factors have been studied in detail through mathematical modeling and positive predictive microbiology. Application of bacteriocin-producing starter cultures in sourdough (to increase competitiveness), in fermented sausage (anti-listerial effect), and in cheese (anti-listerial and anti-clostridial effects), have been studied during in vitro laboratory fermentations as well as on pilot-scale level. The highly promising results of these studies underline the important role that functional, bacteriocinogenic LAB strains may play in the food industry as starter cultures, co-cultures, or bioprotective cultures, to improve food quality and safety. In addition, antimicrobial production by probiotic LAB might play a role during in vivo interactions occurring in the human gastrointestinal tract, hence contributing to gut health.

  10. Effects of bacteriocins on methicillin-resistant Staphylococcus aureus biofilm.

    Science.gov (United States)

    Okuda, Ken-ichi; Zendo, Takeshi; Sugimoto, Shinya; Iwase, Tadayuki; Tajima, Akiko; Yamada, Satomi; Sonomoto, Kenji; Mizunoe, Yoshimitsu

    2013-11-01

    Control of biofilms formed by microbial pathogens is an important subject for medical researchers, since the development of biofilms on foreign-body surfaces often causes biofilm-associated infections in patients with indwelling medical devices. The present study examined the effects of different kinds of bacteriocins, which are ribosomally synthesized antimicrobial peptides produced by certain bacteria, on biofilms formed by a clinical isolate of methicillin-resistant Staphylococcus aureus (MRSA). The activities and modes of action of three bacteriocins with different structures (nisin A, lacticin Q, and nukacin ISK-1) were evaluated. Vancomycin, a glycopeptide antibiotic used in the treatment of MRSA infections, showed bactericidal activity against planktonic cells but not against biofilm cells. Among the tested bacteriocins, nisin A showed the highest bactericidal activity against both planktonic cells and biofilm cells. Lacticin Q also showed bactericidal activity against both planktonic cells and biofilm cells, but its activity against biofilm cells was significantly lower than that of nisin A. Nukacin ISK-1 showed bacteriostatic activity against planktonic cells and did not show bactericidal activity against biofilm cells. Mode-of-action studies indicated that pore formation leading to ATP efflux is important for the bactericidal activity against biofilm cells. Our results suggest that bacteriocins that form stable pores on biofilm cells are highly potent for the treatment of MRSA biofilm infections.

  11. The bacteriocin bactofencin A subtly modulates gut microbial populations.

    Science.gov (United States)

    Guinane, Caitriona M; Lawton, Elaine M; O'Connor, Paula M; O'Sullivan, Órla; Hill, Colin; Ross, R Paul; Cotter, Paul D

    2016-08-01

    The diverse and dynamic microbiota of the gastrointestinal tract represents a vast source of bioactive substances. These include bacteriocins, which are antimicrobial peptides with the potential to modulate gut populations to impact positively on human health. Although several gut-derived bacteriocins have been isolated, there remain only a few exceptional studies in which their influence on microbial populations within the gut has been investigated. To facilitate such investigations, in vitro faecal fermentation systems can be used to simulate the anaerobic environment of the colon. In this instance, such a system was employed to explore the impact of bactofencin A, a novel broad spectrum class IId bacteriocin produced by gut isolates of Lactobacillus salivarius, on intestinal populations and overall microbial diversity. The study reveals that, although bactofencin A is a broad spectrum bacteriocin, it has a relatively subtle influence on intestinal communities, with a potentially positive impact on anaerobic populations such as Bacteroides, Clostridium and Bifidibacterium spp. The strategy taken is an important first step in investigating the merits of using bactofencin A to manipulate the gut microbiota in a beneficial way for health. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Separation of a Bacteriocin-Producing Lactic Acid Bacteria Strain from Pickles%泡菜中产细菌素的乳酸茵分离研究

    Institute of Scientific and Technical Information of China (English)

    胡杨; 项松涛; 杨宇清; 郑一敏; 王琳琳; 胥秀英; 曾品涛; 李杰

    2012-01-01

    实验从泡菜中分离出一株有抑制革兰氏阳性细菌、革兰氏阴性细菌作用的菌株,经鉴定为乳酸菌中的肠膜明串殊菌,该抗菌物质对蛋白水解酶敏感,耐热并在较宽的pH值范围内保持活性。在排除是有机酸和过氧化氢后,初步认为该菌产生的抗菌物质为抗菌肽,即细菌素。%A lactic acid bacteria strain was isolated from traditional food pickles. It was identified to be Leuconostoc mesenteroides. The strain was found to produce an extracellular antimicrobial substance that was peptide in nature (bacteriocin) and effective against Gram-positive bacteria and Gram-negative bacteri- a. The antimicrobial peptide was assayed as non-organic acid and non-hydrogen peroxide and sensitive to proteolytic enzymes, resistant to heat and active over a wide range of pH.

  13. Expression of bacteriocin divercin AS7 in Escherichia coli and its functional analysis.

    Science.gov (United States)

    Olejnik-Schmidt, Agnieszka K; Schmidt, Marcin T; Sip, Anna; Szablewski, Tomasz; Grajek, Włodzimierz

    2014-01-01

    Bacteriocins are small peptides with antimicrobial activity, that are produced by bacteria. Four classes of bacteriocins produced by lactic acid bacteria have been defined. Class IIa bacteriocins are promising candidates for industrial applications due to their high biological activity and their physicochemical properties. Divercin AS7 is a class IIa bacteriocin produced by Carnobacterium divergens AS7. It shows antibacterial activity against pathogens and food spoilage flora including Listeria spp. Little is known about the impact of class IIa bacteriocins upon eukaryotic cells. The safe use of bacteriocins as food biopreservatives requires the absence of cytotoxicity to human cells. To analyze the impact of divercin AS7 on human enterocytes, we expressed the recombinant divercin AS7 in the Escherichia coli BL21DE3pLys strain and conducted in vitro studies to evaluate the safety of recombinant divercin AS7. No cytotoxic effect on differentiated monolayer Caco-2 cells and no apoptotic appearance were observed when recombinant divercin AS7 was used at a concentration of 2 μg ml(-1). In our study, divercin AS7 also did not interfere with differentiated Caco-2 cells monolayer integrity. The obtained results suggest that divercin AS7 is a promising peptide for the food industry.

  14. Influence of media and temperature on bacteriocin production by Bacillus cereus 8A during batch cultivation.

    Science.gov (United States)

    Bizani, D; Brandelli, A

    2004-08-01

    Cerein 8A is a bacteriocin produced by the soil bacterium Bacillus cereus 8A, isolated from native woodlands of Brazil. The influence of temperature and media on the growth of B. cereus 8A and the production of this bacteriocin was studied during batch cultivation. Maximum activity was detected by cultivation in brain/heart infusion broth, reaching 3200 activity units ml(-1). Bacteriocin was also produced in peptone, MRS, Mueller-Hinton and nutrient broth, while no activity was observed during cultivation in thioglycollate or tryptic soy broth. Temperature had a strong influence on bacteriocin production, which was higher at 30 degrees C than at 25 degrees C. An important decrease in bacteriocin activity was observed at 37 degrees C. The relationship between growth and specific production rates, as a function of the temperature, showed different kinetics of production and there were several peaks in the specific production rates during growth. Bacteriocin was produced at the stationary phase, indicating it is synthesized as a secondary metabolite.

  15. Bioprotective potential of bacteriocinogenic Enterococcus gallinarum strains isolated from some Nigerian fermented foods, and of their bacteriocins.

    Science.gov (United States)

    Oladipo, Iyabo C; Sanni, Abiodun I; Writachit, Chakraborty; Chakravorty, Somnath; Jana, Sayantan; Rudra, Deep S; Gacchui, Ratan; Swarnakar, Snehasikta

    2014-01-01

    Enterococcus gallinarum strains isolated from some Nigerian fermented foods were found to produce bacteriocins. The bacteriocins had a broad spectrum of activity against both Gram-positive and negative bacteria. The effects of the bacteriocins and bacteriocinogenic organ- isms on Staphylococcus aureus infections in rats were evaluated. Sprague-Dawley rats were infected with S. aureus MTCC 737 and treated with E. gallinarum T71 and different concentrations of the bacteriocins from E. gallinarum W211 and T71. Staphylococcus aureus infection caused significant upregulation of aspartate aminotransferase and alanine aminotransferase levels in sera of the infected rats. Moreover, gelatin zymography revealed that infected gastric tissues showed elevated matrix metalloproteinase-9 activity. Bacteriocin treatments reduced the MMP-9 activity and inhibited the expressions of both Tumour Necrosis Factor Alpha (TNF-α) and Interleukin-1 Beta (IL-1β) dose dependently, pointing to a potential role of the bacteriocins in attenuating inflammatory responses to Staphylococcus aureus infec- tion. Gastric and GIT damage caused by staphylococcal infection were reduced in the Enterococcus gallinarum T71 and bacteriocin-treated groups also dose dependently. We conclude that these bacteriocins may have useful biomedical applications.

  16. 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.

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

    Directory of Open Access Journals (Sweden)

    Danielle N. Furtado

    2014-12-01

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

  18. 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

    Aims: To investigate factors influencing bacteriocin production and bacteriocin stability of the bioprotective culture Carnobacterium piscicola strain A9b. Methods and Results: Maximum activity was obtained in MRS7 broth (MRS adjusted to pH 7.2), with or without glucose. No bacteriocin was produced...... 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...

  19. Peptide Bacteriocins--Structure Activity Relationships.

    Science.gov (United States)

    Etayash, Hashem; Azmi, Sarfuddin; Dangeti, Ramana; Kaur, Kamaljit

    2015-01-01

    With the growing concerns in the scientific and health communities over increasing levels of antibiotic resistance, antimicrobial peptide bacteriocins have emerged as promising alternatives to conventional small molecule antibiotics. A substantial attention has recently focused on the utilization of bacteriocins in food preservation and health safety. Despite the fact that a large number of bacteriocins have been reported, only a few have been fully characterized and structurally elucidated. Since knowledge of the molecular structure is a key for understanding the mechanism of action and therapeutic effects of peptide, we centered our focus in this review on the structure-activity relationships of bacteriocins with a particular focus in seven bacteriocins, namely, nisin, microcin J25, microcin B17, microcin C, leucocin A, sakacin P, and pediocin PA-1. Significant structural changes responsible for the altered activity of the recent bacteriocin analogues are discussed here.

  20. Características da bacteriocina produzida por Lactococcus lactis ssp. hordniae CTC 484 e seu efeito sobre Listeria monocytogenes em carne bovina Characterisation of the bacteriocin produced by Lactococcus lactis ssp. hordniae CTC 484 and the effect of this compound on Listeria monocytogenes in beef

    Directory of Open Access Journals (Sweden)

    Renata Bromberg

    2006-03-01

    Full Text Available O isolamento de linhagens de bactérias lácticas produtoras de bacteriocinas em carnes e seus produtos derivados resultou na detecção de Lactococcus lactis ssp. hordniae CTC 484, proveniente de frango. A bacteriocina inibiu não apenas uma outra bactéria láctica (Lactobacillus helveticus, mas também microorganismos patogênicos (Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus, Clostridium perfringens e Enterococcus faecalis. Ela foi inativada por causa de enzimas como: alfa-quimotripsina, tripsina, pronase E, ficina, pepsina, papaína e lipase. Além disso, a bacteriocina mostrou-se termoestável, mesmo a temperaturas de autoclavagem (121°C/10 min e foi produzida em condições de armazenamento sob refrigeração. A bacteriocina mostrou-se ativa dentro de uma ampla faixa de valores de pH (2-10, porém a maior atividade ocorreu em valores menores de pH. A eficiência da linhagem CTC 484, assim como a de sua bacteriocina na redução e inibição do crescimento de Listeria monocytogenes em carne bovina estéril, foram avaliadas. Os resultados indicaram que o tratamento da carne por meio da inoculação desta bactéria contribuiu para o aumento da segurança e extensão da vida útil deste alimento.Screening for the bacteriocin production of strains of lactic acid bacteria from various meat and meat products resulted in the detection of a bacteriocin-producing Lactococcus lactis ssp. hordniae CTC 484, isolated from chicken. The bacteriocin inhibited not only closely related lactic acid bacterium (Lactobacillus helveticus, but also pathogenic microorganisms (Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus, Clostridium perfringens, and Enterococcus faecalis. This compound was inactivated by alpha-chymotrypsin, trypsin, pronase E, ficin, pepsin, papain, and also by lipase. It was heat stable even at autoclaving temperature (121°C/10 min and was produced under refrigerated storage. It was also active over a wide

  1. 1株产细菌素植物乳杆菌的筛选及所产细菌素的理化性质分析%Study on Screening of Lactobacillus Plantarum for Producing Bacteriocin and its Physicochemical Characteristics

    Institute of Scientific and Technical Information of China (English)

    刘丽; 郝彦玲; 张红星; 谢英; 周绪宝

    2011-01-01

    Strain LH-09, isolated from ham products in Zhejiang province, produced antimicrobial substance which was inhibitory to Listeria monocytogenes 54003. Strain LH-09 was identified as Lactobacillus plantarum by using 16S rRNA gene sequence homology analysis. After eliminating the effect of organic acid and hydrogen peroxide, the antimicrobial substance with its proteinaceous nature was confirmed as bacteriocin. Bacteriocin LH-09 was heat-stable and remained activity after incubation at a wide pH. It could be degraded by proteases existing in the human body. Tricine-SDS-PACE showed that its molecular weight was between 2-6 kDa. In this paper a preliminary study on the bacteriocin producted by Lactobacillus plantarum had been made to lay the basis for the development of natural food preservative.%从浙江省生产的一种火腿制品中分离筛选到1株具有抑菌活性的乳酸菌菌株LH-09,对单核细胞增生李斯特菌ATCC54003的生长具有良好的抑制作用.16SrRNA序列同源性分析鉴定乳酸菌LH-09为植物乳杆菌.在排除有机酸、过氧化氢的干扰后,确定该抑菌物质为蛋白类物质,即细菌素.理化性质分析表明细菌素LH-09具有较好的热稳定性、酸碱稳定性,可被人体内蛋白酶降解.N-羟甲基甲基甘氨酸-SDS-PAGE电泳确定细菌素LH-09的分子质量在2~6 kDa之间.

  2. 和田地区酸奶中产细菌素乳酸菌的筛选及细菌素特性的研究%Screening of bacteriocin-producing lactic acid bacteria from Hetian yoghourt and characterization of the bacteriocin

    Institute of Scientific and Technical Information of China (English)

    王东梅; 刘飞; 马翠云; 陈红征

    2012-01-01

    从和田地区酸奶中筛选出了乳酸菌A3,其所产抑菌物质在排除过氧化氢和有机酸的干扰及蛋白酶失活实验后,可以初步确定是一种细菌素。该细菌素对热较稳定,在酸性条件下表现出很好的抑菌活性,同时具有广谱的抑菌活性。根据该菌株的形态和生理生化特性,将A3菌株初步鉴定为肠膜明串珠菌(Leuconostoc mesenteroides)。%The lactic acid bacteria A3 was isolated from Hetian yoghourt. The bacteriostasis material was determined as bacteriocin after excluding interference of organic acid, H202 and inactivation of proteinase. The bacteriocin had good heat stability and high antibacterial activity under acid conditions. It also had broad-spectrum effects on bacteriostasis. Through detection of its appearance, physiological and biochemical characteristics, A3 was identified as Leuconostoc mesenteroides.

  3. [Characteristic, properties, prospect of application of bacteriocins].

    Science.gov (United States)

    Balko, A B

    2012-01-01

    Literary data and own research results dedicated to bacteriocin investigations have been analysed. Bacteriocins as one of the most widespread factors of bacterial antagonism, which are distinguished by the majority of microorganisms and characterized by bactericidal action in respect of representatives of phylogenetically related species have been considered. Allowing for their high lytic activity and narrow action specificity, the prospects for the use of the bacteriocins as possible alternative antibacterial remedies are examined. The basic approaches to bacteriocin classification, their variety, structure, killer properties and mechanisms of lytic action are presented. The perspective trends of the use and possible significance of these antibacterial substances in medicine are indicated.

  4. Development of Freeze-Dried Bacteriocin-Containing Preparations from Lactic Acid Bacteria to Inhibit Listeria monocytogenes and Staphylococcus aureus.

    Science.gov (United States)

    Dimitrieva-Moats, Galina Yu; Ünlü, Gülhan

    2012-03-01

    There has been a recent movement to produce and consume "minimally processed" and more "natural" foods through the use of fewer chemical preservatives. The shift to more "natural" foods has resulted in a great interest in the use of bacteriocins from lactic acid bacteria as natural biopreservatives. The objective of this comparative study was to identify bacteriocins that can be produced in low-cost or no-cost dairy-based media (DBM), concentrated using freeze-drying, and applied to Cheddar cheese samples to concurrently inhibit Listeria monocytogenes and Staphylococcus aureus. Select bacteriocin producers were grown in DBM, their cell-free supernatants (CFS) were frozen, and the frozen CFS samples were freeze-dried to produce bacteriocin-containing powders. Cheddar cheese samples were challenged with L. monocytogenes or Staph. aureus cells. The challenged samples were exposed to buffered solutions of freeze-dried powders containing bacteriocins, incubated at 4 °C for 24-72 h, and plated onto appropriate selective media. All freeze-dried bacteriocin-containing powders tested were active against L. monocytogenes and Staph. aureus. Our research findings indicated that low-cost or no-cost DBM could successfully be used for production of bacteriocin-containing preparations. In addition, freeze-drying was determined to be a feasible approach to prepare concentrated and stable bacteriocin-containing powders for prospective food applications. The prevention of even a very small percentage of foodborne illnesses via the use of bacteriocins as natural biopreservatives would help reduce the number of foodborne illness-related hospitalizations, deaths, and financial loss due to medical expenses, lost income/productivity, cost of litigation/penalties, and loss of trade.

  5. 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.

  6. Growth-inhibition of hiochi bacteria in namazake (raw sake) by bacteriocins from lactic acid bacteria.

    Science.gov (United States)

    Taniguchi, Masayuki; Ishiyama, Yohei; Takata, Takeomi; Nakanishi, Toshihiro; Kaneoke, Mitsuoki; Watanabe, Ken-ichi; Yanagida, Fujitoshi; Chen, Yi-sheng; Kouya, Tomoaki; Tanaka, Takaaki

    2010-06-01

    The bacteriocins produced by Lactococcus lactis subsp. lactis C101910 (C101910) and NBRC 12007 (NBRC 12007) were used to prevent the growth of sake spoiling hiochi bacteria (Lactobacillus hilgardii, Lactobacillus fructivorans, and Lactobacillus paracasei) in namazake, which is raw (unpasteurized) sake. The bacteriocin concentrations required for decreasing the viable cell concentrations of L. hilgardii and L. fructivorans below the detection limit (1.0 x 10(2) cells/ml) in 24 h from the initial concentration of 4.0-9.5 x 10(5) cells/ml in the namazake at pH 4.5 and at 4 degrees C, were 18-35 U/ml and 5.6 U/ml for the bacteriocin from C101910 and NBRC 12007, respectively. To decrease the viable cell concentration of L. paracasei from the initial concentration of 7.5 x 10(5) cells/ml to below the detection limit (1.0 x 10(2) cells/ml) in 24 h, 350 U/ml bacteriocin from C101910 and 140 U/ml bacteriocin from NBRC 12007 were required. In experiments using McIlvaine buffer (pH 4.5) with 15% ethanol instead of namazake as the medium, the viable cell concentrations of L. hilgardii and L. paracasei decreased to less than 1.0 x 10(2) cells/ml, whereas those of L. fructivorans decreased to less than 1.0 x 10(3) cells/ml, when bacteriocins were added at the concentrations that had proven effective in namazake. The membrane depolarization assay using a fluorescent probe showed that the presence of ethanol stimulated the collapse of the membrane potential induced by bacteriocins. The ethanol induced collapse of the membrane potential suggests that the application of bacteriocins at the storage stage of namazake is more beneficial than when used in other stages of the sake brewing process.

  7. Characteristics and optimization producing conditions of bacteriocin-like from Lactobacillus plantrum%植物乳酸菌类细菌素特性研究及其产生条件的优化

    Institute of Scientific and Technical Information of China (English)

    解俊梅; 文汉

    2011-01-01

    Lactobacillus production of lactic acid bacteria bacteriocin culture conditions was optimized by single factor experiment and orthogonal and its characteristics was analyzed.The results showed that:the best vegetative growth of lactic acid bacteria was a combination of culture conditions at 30℃,initial pH6.0 with inoculum amount of 4%,seed age 12h,anaerobic conditions for 40h.Lactobacillus streptozotocin on Gram-negative bacteria and yeast inhibition optimum culture conditions for the largest combination of the temperature 28℃,initial pH7.0 with inoculum amount of 2%,seed age 10h,anaerobic conditions for 24h.Gram-positive lactic acid bacteria Streptomyces antibacterial effects had the best combination of culture conditions of temperature 28℃,initial pH 6.5 medium,inoculum 1%,seed age 6h,anaerobic conditions for 40h.Without effect of organic acids and hydrogen peroxide,the cell-free liquid culture of Lactobacillus showed high inhibitory activity against gram-positive bacterias,including Bacillus subtilis and Staphyloccocus aureus Rosenbach and gram-negative bacterias,such as Escherichia coli and Salmonella typhimunius,but also inhibited some fungi.Therefore,the inhibitory substance produced by the lactic acid bacteria was assumed bacteriocin-like substance.Lactic acid bacteria showed it was stable to heat,active at low pH,not sensitive to proteinasea and broad antibacterial spectrum.%通过单因素实验和正交实验优化了乳酸菌产乳酸菌素的培养条件并分析了其特性。结果表明:植物性乳酸杆菌生长的最佳培养条件组合是温度30℃,培养基初始pH为6.0,接种量4%,种龄12h,厌氧条件下,培养时间40h;乳酸菌菌素对革兰氏阴性菌和酵母菌的抑菌作用最大的最佳培养条件组合是温度28℃,培养基初始pH为7.0,接种量2%,种龄10h,厌氧条件下,培养时间24h。乳酸菌菌素革兰氏阳性菌的抑菌作用最大的最佳培养条件组合是温度28℃,培养基初始pH为6.5,

  8. Bacteriocin from Bacillus subtilis as a novel drug against diabetic foot ulcer bacterial pathogens

    Institute of Scientific and Technical Information of China (English)

    Baby Joseph; Berlina Dhas; Vimalin Hena; Justin Raj

    2013-01-01

    Objective:To isolate and identify Bacillus subtilis (B. subtilis) from soil and to characterize and partially purify the bacteriocin. To evaluate the antimicrobial activity against four diabetic foot ulcer bacterial pathogens. Methods:Genotypic identification was done based on Bergey’s manual of systemic bacteriology. Antimicrobial susceptibility test was done by Kirby-Bauer disc diffusion method. Colonies were identified by colony morphology and biochemical characterization and also compared with MTCC 121 strain. Further identification was done by 16S rRNA sequencing. Inhibitory activities of partially purified bacteriocin on all the DFU isolates were done by agar well diffusion method. The strain was identified to produce bacteriocin by stab overlay assay. Bacteriocin was extracted by organic solvent extraction using chloroform, further purified by HPLC and physical, and chemical characterization was performed. Results: The four isolates showed high level of resistance to amoxyclav and sensitivity to ciprofloxacin. HPLC purification revealed that the extracts are bacteriocin. The phylogenetic tree analysis results showed that the isolate was 99%related to B. subtilis BSF01. The results reveled activity to all the four isolates and high level of activity was seen in case of Klebsiella sp. Conclusions:Partially purified bacteriocin was found to have antimicrobial activity against the four diabetic foot ulcer bacterial pathogens, which can thus be applied as a better drug molecule on further studies. The strain B. subtilis are found to be safe for use and these antimicrobial peptides can be used as an antimicrobial in humans to treat DFU bacterial pathogens.

  9. Food biopreservation: Promising strategies using bacteriocins, bacteriophages and endolysins

    OpenAIRE

    García Suárez, María Pilar; Rodríguez,Lorena; Rodríguez González, Ana; Martínez Fernández, Beatriz

    2010-01-01

    The interest in biopreservation of food has prompted the quest for new natural antimicrobial compounds from different origins. Bacteriocins have been widely recognized as natural food biopreservatives but lastest advances on bateriocin biology have opened new fields to explore. On the contrary, the use of bacteriophages and endolysins has only been considered in the last five years and recent developments have produced promising perspectives. This review provides an overview of the current an...

  10. Isolation and identification of lactic acid bacteria producing anti-Staphylococcus aureus bacteriocin%分泌抗金黄色葡萄球菌细菌素乳酸菌的分离鉴定

    Institute of Scientific and Technical Information of China (English)

    王全溪; 许丽惠; 邓红玉; 吴雪珍; 庄育彬

    2014-01-01

    为分离和筛选产抗金黄色葡萄球菌乳酸菌素的优势乳酸菌,利用乳酸菌分离培养基MRS从收集的各种腌制菜汁中分离培养乳酸菌,通过细菌培养特性、革兰氏染色特点、生理生化特性初步鉴定,同时根据Genbank中乳酸菌的16S rDNA 序列设计特异性引物,采用PCR方法进一步鉴定,并以金黄色葡萄球菌为指示菌对乳酸菌的发酵上清液进行抑菌特性研究。结果表明,从腌渍菜汁中分离获得90株产酸菌,通过形态学、生理生化特性和PCR鉴定,结果73株产酸菌为乳酸杆菌;分泌产物抑菌试验表明,有10株菌具有抑制金黄色葡萄球菌活性,经酸排除和过氧化氢排除试验,仍然有5株乳酸菌的分泌产物具有抑制金黄色葡萄球菌活性。可见,从腌渍菜汁分离到的乳酸菌具有抑制金黄色葡萄球菌活性的特性,主要是通过分泌乳酸菌素来发挥作用。%The study was carried out to separate the lactic acid bacteria which could produce the bacteriocin against S.aureus. In this experiment, the lactic acid bacteria were isolated from the salted and preserved vegetables with the MRS medium. Identification was done by bacterial culture characteristics, Gram stain characteristics, physiological and biochemical characterization, And the bacteria was identified by PCR. The antibacterial properties of lactic acid bacteria fermentation supernatant was studied. The results showed that 73 strains acid-producing bacteria were isolated, and were identified to Lactobacillus by morphological characteristics, biochemi-cal characteristics and PCR. The antibacterial test showed that there were ten strains Lactobacillus which secretory products could in-hibit staphylococcus aureus. Ruled out by acid and hydrogen peroxide exclusion experiments, there were still 5 strains of lactic acid bacteria which secretion can inhibit staphylococcus aureus. Therefore, in this experiment the lactic acid

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

    Directory of Open Access Journals (Sweden)

    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. Research Antifungal Activity on Bacteriocin Produced by Lactic Acid Bacteria from Traditional Sour Cabbage%传统酸菜中具有抗真菌特性乳酸菌素的研究

    Institute of Scientific and Technical Information of China (English)

    李传娟; 双全; 栗永乐; 萨如拉; 桑木信辅; 琢田爱

    2012-01-01

    The antibacterial ability of lactic acid bacteria (LAB), which isolated from the sour cabbage juice prepared by herdsman in the east Inner Mogolia Region, were determined by Plate punch diffusion method, and the extracellulary bacteriocins of one screening strain was partial purified by gel filtration Sephadex G-15, and its biochemical characteristics were assessed in vitro. The results showed that strain S1-4 of LAB, which was screened out from 84 tested strains, had a broad spectrum antibacterial fungi property. Purified extracellulary bacteriocins from strain S1-4 was characterised as a proteinaceous substance. This bacteriocins compound, molecular mass ranged from 6.5 kDa to 8 kDa, has thermal stability and acid tolerance with an optimum antibacterial ability at pH 4.0.%通过平板打孔扩散法测定从内蒙古东部地区传统酸菜汁中分离的乳酸菌(LAB)的抑菌能力,再用葡聚糖凝胶G-15对筛选乳酸菌的胞外细菌素进行分离及特性研究。结果显示,84株供试乳酸菌中筛选出1株具有广谱抗真菌能力的乳酸菌S1-4。该乳酸菌所产生的胞外抑菌素属蛋白类物质,具有热稳定和耐酸特性,在pH4.0时抑菌效果最佳,其分子量约为6.5KDa~8kDa。

  14. 乳酸菌细菌素作为天然生物防腐剂在食品工业中的应用进展%Advances on Application of Bacteriocins Produced by Lactic Acid Bacteria as Natural Bio-preservative in Food Industry

    Institute of Scientific and Technical Information of China (English)

    刘国荣; 李平兰; 王成涛

    2012-01-01

    Bacteriocins were antibacterial activity protein or peptide produced by lactic acid bacteria,and they were identified with great potential as natural food bio-preservative because of their strongly antibacterial activity against food borne pathogens and spoilage organism.In this review,the development of the application of bacteriocin as preservative in food industry was reviewed.The existing problems and future research consideration were pointed out.%乳酸菌细菌素是乳酸菌在代谢过程中合成的天然抑菌多肽或蛋白质,由于其对食品腐败菌和致病菌的强烈抑菌活性,已成为天然食品生物防腐剂研究与开发的热点.对乳酸菌细菌素在食品工业中的应用研究作了全面系统的综述,并指出了目前存在的主要问题和今后的研究方向.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. Administrative Circulars

    CERN Multimedia

    Département des Ressources humaines

    2004-01-01

    Administrative Circular N° 2 (Rev. 2) - May 2004 Guidelines and procedures concerning recruitment and probation period of staff members This circular has been revised. It cancels and replaces Administrative Circular N° 2 (Rev. 1) - March 2000. Administrative Circular N° 9 (Rev. 3) - May 2004 Staff members contracts This circular has been revised. It cancels and replaces Administrative Circular N° 9 (Rev. 2) - March 2000. Administrative Circular N° 26 (Rev. 4) - May 2004 Procedure governing the career evolution of staff members This circular has also been revised. It Administrative Circulars Administrative Circular N° 26 (Rev. 3) - December 2001 and brings up to date the French version (Rev. 4) published on the HR Department Web site in January 2004. Operational Circular N° 7 - May 2004 Work from home This circular has been drawn up. Operational Circular N° 8 - May 2004 Dealing with alcohol-related problems...

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

    Science.gov (United States)

    Todorov, Svetoslav D

    2009-04-01

    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.

  18. Recent patents on bacteriocins: food and biomedical applications.

    Science.gov (United States)

    Benmechernene, Zineb; Fernandez-No, Inmaculada; Kihal, Mebrouk; Böhme, Karola; Calo-Mata, Pilar; Barros-Velazquez, Jorge

    2013-04-01

    Most types of bacteria produce bacteriocins, which are proteinaceous extracellular compounds that can inhibit the growth of other undesirable microorganisms. Bacteriocins are receiving increasing attention, due to their many applications, ranging from their initial application in strategies for food preservation to more recent proposed uses in biomedical strategies aimed at fighting certain bacterial infections. Thus, while nisin has a long history of use as a safe additive in certain food products for the purpose of food preservation, certain bacteriocin-producing lactic acid bacteria, which are generally recognised as safe microorganisms, or their extracellular extracts are receiving increased attention as protective cultures or antimicrobial extracts in minimally processed food products. More recently, a number of these bacteriocinproducing cultures have been proposed for use in other applications, such as in probiotics, for the inhibition of biofilms in the food industry, or even as coadjuvants of combined therapeutical strategies along with other antimicrobial agents in biomedical applications. This review aims to provide a brief overview of the most relevant recent patents in this field.

  19. Two-Component Regulatory Systems – implication in the quorum sensing mechanisms and bacteriocin production in lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Lia–Mara Ditu

    2014-08-01

    Full Text Available For lactic acid bacteria, the mechanisms of quorum sensing and response are mediated by peptides or pheromones that interfere with the synthesis of antimicrobial peptides (AMP called bacteriocins, when these molecules reach a certain critical level of concentration. Generally, the synthesis and activity of pheromones is adjusted by means of a two-component regulatory system. The observation that some microorganisms, in particular lactic acid bacteria, produce bacteriocins according to the cell density, has led to the discovery of the involvement of QS mechanisms in the synthesis of these peptides. Bacteriocins synthesis is inducible, the process requiring the extracellular accumulation of peptides that functions as chemical messengers activators of bacteriocins synthesis. This minireview presents the molecular architecture and functions of two-component regulatory systems and ABC transporters implicated in the synthesis and secretion of nisin, one of the most studied bacteriocin. The elucidation of the intimate mechanisms of bacteriocins synthesis is equally of biotechnological and medical importance, opening interesting perspectives for the development of improved technologies for the production of bacteriocins with good yields, and also, for increasing the beneficial anti-infective roles of probiotic bacteria when administered in vivo.

  20. 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.

  1. 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

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

    Science.gov (United States)

    Ghequire, Maarten G K; Kemland, Lieselore; Anoz-Carbonell, Ernesto; Buchanan, Susan K; De Mot, René

    2017-02-21

    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.IMPORTANCE In their continuous struggle for ecological space, bacteria face a huge load of contenders, including phylogenetically related strains that compete for the same niche. One important group of secreted antibacterial proteins assisting in eliminating these rivals are modular bacteriocins of Gram-negative bacteria, comprising a domain for docking onto the

  3. The Potential of Class II Bacteriocins to Modify Gut Microbiota to Improve Host Health

    Science.gov (United States)

    Umu, Özgün C. O.; Bäuerl, Christine; Oostindjer, Marije; Pope, Phillip B.; Hernández, Pablo E.; Pérez-Martínez, Gaspar; Diep, Dzung B.

    2016-01-01

    Production of bacteriocins is a potential probiotic feature of many lactic acid bacteria (LAB) as it can help prevent the growth of pathogens in gut environments. However, knowledge on bacteriocin producers in situ and their function in the gut of healthy animals is still limited. In this study, we investigated five bacteriocin-producing strains of LAB and their isogenic non-producing mutants for probiotic values. The LAB bacteriocins, sakacin A (SakA), pediocin PA-1 (PedPA-1), enterocins P, Q and L50 (enterocins), plantaricins EF and JK (plantaricins) and garvicin ML (GarML), are all class II bacteriocins, but they differ greatly from each other in terms of inhibition spectrum and physicochemical properties. The strains were supplemented to mice through drinking water and changes on the gut microbiota composition were interpreted using 16S rRNA gene analysis. In general, we observed that overall structure of the gut microbiota remained largely unaffected by the treatments. However, at lower taxonomic levels, some transient but advantageous changes were observed. Some potentially problematic bacteria were inhibited (e.g., Staphylococcus by enterocins, Enterococcaceae by GarML, and Clostridium by plantaricins) and the proportion of LAB was increased in the presence of SakA-, plantaricins- and GarML-producing bacteria. Moreover, the treatment with GarML-producing bacteria co-occurred with decreased triglyceride levels in the host mice. Taken together, our results indicate that several of these bacteriocin producers have potential probiotic properties at diverse levels as they promote favorable changes in the host without major disturbance in gut microbiota, which is important for normal gut functioning. PMID:27695121

  4. 泡菜中产细菌素乳酸菌的筛选及特性研究%Screening and Characteristics of Bacteriocin-producing Lactic Acid Bacteria in PickIes

    Institute of Scientific and Technical Information of China (English)

    刘阳; 何义国; 赵兴秀; 赵长青; 张静; 邹伟

    2016-01-01

    Four lactic acid bacteria with good antibacterial properties are isolated from pickles by dilution coated plate method for separating,plate streak method for purifying,filtering paper method for preliminary screening,oxford cup method for secondary screening.Neutralization elimination of interference factors such as organic acid and hydrogen peroxide,fermented liquid still has strong bacteriostatic action.After being treated with protease and trypsin,the antibacterial performance of fermented liquid is significantly reduced, thus antibacterial material is determined as a kind of bacteriocin with protein properties.Through the morphology,growth condition and physiological and biochemical identification, preliminarily determine 4 strains of bacteria are all Lactobacillusplantarum.To further study the antibacterial ability of L-33 strain,its bacteriocin pH activity range is 5.0~9.0 and the antibacterial activity is the highest at pH 7.0.It has thermal stability and broad-spectrum bacteriocin inhibitory effect on gram positive bacteria and gram negative bacteria.%以泡菜为原材料,经稀释涂布平板法分离、平板划线法纯化、滤纸片法初筛和牛津杯法复筛得到4株有较好抑菌性能的乳酸菌。中和法排除有机酸及过氧化氢等干扰因素后,发酵液仍有较强的抑菌作用;用蛋白酶和胰蛋白酶处理后,发酵液抑菌性能明显降低,因而确定抑菌物质是一种具备蛋白质性质的细菌素。经形态学、生长条件和生理生化鉴定,初步确定4株菌均为植物乳杆菌。对抑菌能力较强的L-33菌株进一步研究,其产生的细菌素pH 活性范围为5.0~9.0,在pH 7.0时抑菌活性最高,且其具有热稳定性,是一种对革兰氏阳性菌和阴性菌都有抑菌效果的广谱细菌素。

  5. Screen and Preliminary Identification of Lactic acid bacteria to Produce Broad-Spectrum Bacteriocin%产广谱细菌素乳酸菌CW3的筛选和初步鉴定

    Institute of Scientific and Technical Information of China (English)

    吕好新; 王巍东; 谈重芳; 杨飞飞; 焦迎春; 王雁萍; 李宗伟

    2013-01-01

    [Objective] CW3 strain was screened and preliminarily identified.[Method] Oxford cup double plate method was adopted to primarily screen spectrum bacteriocin,then excluding acid and hydrogen peroxide disturbance,the protein property of anti-bacteria material was detected,the strain of rescreening was identified.[Result] The supernatant of CW3 strain can inhibit the growth of indicator strains excluded hydrogen peroxide and organic acid.The inhibitive activity decreased largely after treatment with trpsin and pepsin,which can draw that the anti-microbial substances were bacteriocin.The results of identification of physiology and biochemistry preliminarily identified that CW3 strain was a Lactobacillus plantarum.[Conclusion] CW3 strain was a Lactobacillus plantarum,which can generate spectrum bacteriocin.%[目的]对CW3菌株进行筛选,并且进行初步鉴定.[方法]首先采用牛津杯双层平板法进行产广谱细菌素菌株的初筛,再将初筛得到的菌株进行排除酸和过氧化氢干扰,并检测抑菌物质的蛋白质性质,最终对复筛得到的菌株进行鉴定.[结果]试验得出,排除有机酸、过氧化氢等干扰因素后,发酵液仍有抑菌作用;用胰蛋白酶和胃蛋白酶处理后,发酵液抑菌活性急剧下降,确定产生的抑菌物质具有蛋白质性质,是一类细菌素.经过生理生化试验初步鉴定菌株CW3为植物乳杆菌.[结论]菌株CW3是一种能产广谱细菌素的植物乳杆菌.

  6. Application of bacteriocins in vegetable food biopreservation.

    Science.gov (United States)

    Settanni, Luca; Corsetti, Aldo

    2008-01-31

    Bacteriocins are generally recognized as "natural" compounds able to influence the safety and quality of foods. In the past years, a lot of works have been aimed to the detection, purification and characterisation of bacteriocins, as well as to their use in food preservation strategies. A list of review articles dealing with the application of bacteriocins to the protection of foods of animal origin is also available in literature, but it lacks for a summary on the utilization of bacteriocins in vegetable foods. These biopreservatives can be used in a number of ways in food systems and this paper mainly focuses on the state-of-the-art application of bacteriocins from lactic acid bacteria (LAB) to promote the microbial stability of both fermented and non-fermented vegetable food products using bacteriocinogenic strains as starter cultures, protective cultures or co-cultures and the employment of pure bacteriocins as food additives. In addition, applications of bacteriocins from non-LAB are also reviewed. The scopes of future directions of research are summarised.

  7. Bacteriocins: New generation of antimicrobial peptides

    Directory of Open Access Journals (Sweden)

    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. Isolation and partial characterization of bacteriocins from Pediococcus species.

    Science.gov (United States)

    Jamuna, M; Jeevaratnam, K

    2004-09-01

    Lactic acid bacteria have received increased attention as a potential food preservative due to their strong antagonistic activity against many food-spoilage and pathogenic organisms. Three Pediococcus species, P. acidilactici NCIM 2292 , P. pentosaceous. NCIM 2296 and P. cervisiae NCIM 2171, were evaluated for bacteriocin production. Inhibitory substance were produced during the late growth phase and maximum production occurred at 37 degrees after 36-48 h of incubation. Bacteriocins partially purified from these species by cold-acetone precipitation at 0 degrees C and cell adsorption desorption techniques have a broad inhibitory spectrum against microorganisms, including gram-negative bacteria such as Escherichia coli and Pseudomonas. Proteolytic enzymes inactivated these peptides, but amylase and lipase did not show any effect. The bacteriocins were stable over a wide pH range (3-8) and apparently most active at pH 4.0-5.0. They were heat-stable (1 h at approximately 80 degrees C and autoclaving) at pH 5.0. No loss in activity was observed when stored under refrigeration (4-8 degrees C). Tris-Tricine SDS-PAGE revealed the molecular masses of these peptides to be between 3.5 and 5.0 kDa.

  9. [Enterocin-35, a bacteriocin with activity against Listeria monocytogenes. Possible use in the food industry].

    Science.gov (United States)

    Concha, R; Farías, M E; Kümmerlin, R; Sesma, F

    1999-01-01

    The in vitro inhibitory activity of enterocin-35 produced by Enterococcus faecium CRL 35, was studied against Listeria monocytogenes, isolated from seafoods. Optimal growth conditions of the enterocin-35 producing strain, for higher bacteriocin production and improve the extraction and purification of these peptides, were applied. A crude extract of enterocin-35 was assayed in a frozen seafood artificially contaminated with Listeria monocytogenes isolate, simulating at laboratory scale an eventual application of this biopreservant in a routine production process at factory level. The feasibility of biopreservation of seafoods by means of bacteriocins is proposed and discussed.

  10. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  12. 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

    2003-01-01

    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

  13. 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

    2003-01-01

    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

  14. 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

  15. 马奶酒中抗单增李斯特氏菌细菌素产生菌的筛选及鉴定%Screening for anti-Listeria bacteriocin-producing lactic acid bacteria from koumiss

    Institute of Scientific and Technical Information of China (English)

    吴敬; 芒来; 贺银凤

    2011-01-01

    144 lactic acid bacteria strains isolated from traditional fermented koumiss were screened for bacteriocin production by double agar diffusion method. After eliminating the effects of organic acid and catalase, the cell free supernatant of one strain named MKB63 showed strong anti-Listeria activity and were identified as Enterococcus faecium by physiological-biochemical characterization. After ammonium sulphate precipitation, dialysis and concentration,the activity was enhanced. But the inhibition activity was lost after treatment of trypsin and proteinase K. The result showed this inhibitory material had the features of protein, and could be classified as bacteriocin.%从内蒙古传统乳制品酸马奶酒中分离出144株乳酸菌,通过双层琼脂平板扩散法筛选出具有明显抑菌作用的菌株.在排除有机酸、H2O2等的干扰后,其中1株乳酸菌的发酵上清液对受试的单核细胞增生李斯特氏菌表现出明显抑制作用;进一步硫酸铵沉淀、透析及浓缩处理后,其抑菌活性显著增强,说明其代谢产物中含有蛋白质类抑菌物质,可能是细菌素.经生理、生化试验和形态学观察,将该菌株鉴定为屎肠球菌(Enterococcus faecium).

  16. 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...

  17. Circular Coinduction

    Science.gov (United States)

    Rosu, Grigore; Goguen, Joseph; Norvig, Peter (Technical Monitor)

    2001-01-01

    Circular coinduction is a technique for behavioral reasoning that extends cobasis coinduction to specifications with circularities. Because behavioral satisfaction is not recursively enumerable, no algorithm can work for every behavioral statement. However. algorithms using circular coinduction can prove every practical behavioral result that we know. This paper proves the correctness of circular coinduction and some consequences.

  18. Examination of Lactic Acid Bacteria to Secretion of Bacteriocins

    Directory of Open Access Journals (Sweden)

    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

  19. Bacteriocins: Recent Trends and Potential Applications.

    Science.gov (United States)

    Bali, Vandana; Panesar, Parmjit S; Bera, Manab B; Kennedy, John F

    2016-01-01

    In the modern era, there is great need for food preservation in both developing and developed countries due to increasing demand for extending shelf life and prevention of spoilage of food material. With the emergence of new pathogens and ability of micro-organisms to undergo changes, exploration of new avenues for the food preservation has gained importance. Moreover, awareness among consumers regarding harmful effects of chemical preservatives has been increased. Globally, altogether there is increasing demand by consumers for chemical-free and minimal processed food products. Potential of bacteriocin and its application in reducing the microbiological spoilages and in the preservation of food is long been recognized. Bacteriocins are normally specific to closely related species without disrupting the growth of other microbial populations. A number of applications of bacteriocin have been reported for humans, live stock, aquaculture etc. This review is focused on recent trends and applications of bacteriocins in different areas in addition to their biopreservative potential.

  20. 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.

  1. Effect of Leuconostoc mesenteroides 11 bacteriocin in the multiplication control of Listeria monocytogenes 4b Efeito da bacteriocina de Leuconostoc mesenteroides 11 no controle da multiplicação de Listeria monocytogenes 4b

    OpenAIRE

    Rafael C.R. Martinez; Martinis,Elaine C. P. De

    2006-01-01

    The activity of a crude preparation of bacteriocin produced by the chicken meat isolate Leuconostoc mesenteroides 11, was evaluated at 8ºC and 15ºC against Listeria monocytogenes. The pathogen was inoculated in a crude preparation of the bacteriocin and its population was enumerated after 0.5 and 10 days. The title of the bacteriocin in the preparation was determined immediately before inoculation and after 10 days of incubation at both temperatures. As a negative control, a non-bacteriocin p...

  2. Purification and genetic characterization of gassericin E, a novel co-culture inducible bacteriocin from Lactobacillus gasseri EV1461 isolated from the vagina of a healthy woman.

    Science.gov (United States)

    Maldonado-Barragán, Antonio; Caballero-Guerrero, Belén; Martín, Virginia; Ruiz-Barba, José Luis; Rodríguez, Juan Miguel

    2016-03-12

    Lactobacillus gasseri is one of the dominant Lactobacillus species in the vaginal ecosystem. Some strains of this species have a high potential for being used as probiotics in order to maintain vaginal homeostasis, since they may confer colonization resistance against pathogens in the vagina by direct inhibition through production of antimicrobial compounds, as bacteriocins. In this work we have studied bacteriocin production of gassericin E (GasE), a novel bacteriocin produced by L. gasseri EV1461, a strain isolated from the vagina of a healthy woman, and whose production was shown to be promoted by the presence of certain specific bacteria in co-culture. Biochemical and genetic characterization of this novel bacteriocin are addressed. We found that the inhibitory spectrum of L. gasseri EV1461 was broad, being directed to species both related and non-related to the producing strain. Interestingly, L. gasseri EV1461 inhibited the grown of pathogens usually associated with bacterial vaginosis (BV). The antimicrobial activity was due to the production of a novel bacteriocin, gassericin E (GasE). Production of this bacteriocin in broth medium only was achieved at high cell densities. At low cell densities, bacteriocin production ceased and only was restored after the addition of a supernatant from a previous bacteriocin-producing EV1461 culture (autoinduction), or through co-cultivation with several other Gram-positive strains (inducing bacteria). DNA sequence of the GasE locus revealed the presence of two putative operons which could be involved in biosynthesis and immunity of this bacteriocin (gaeAXI), and in regulation, transport and processing (gaePKRTC). The gaePKR encodes a putative three-component regulatory system, involving an autoinducer peptide (GaeP), a histidine protein kinase (GaeK) and a response regulator (GaeR), while the gaeTC encodes for an ABC transporter (GaeT) and their accessory protein (GaeC), involved in transport and processing of the

  3. 产Ⅱ a类细菌素乳酸菌的筛选及鉴定%Screening and identification of class Ⅱa bacteriocin-producing lactic acid bacteria

    Institute of Scientific and Technical Information of China (English)

    岳喜庆; 闵钟熳; 郭晨; 蔡玮璠

    2011-01-01

    352 lactic acid bacterial strains were isolated from fermented Chinese cabbage juice, cucumber juice,barley juice, corn juice, fresh milk, traditional cheese, and red tea. One strain against Listeria monocytogenes and Escherichia coli was selected by double-agar diffusion method. After eliminating some interference factors, such as the organic acid and hydrogen peroxidex, the supernatant of the strain exhibited inhibitory effect against the indicator strain. However,when treated with trypsin, pepsin and papain, the inhibitory activity lost totally. Therefore, the inhibitory material which has the features of protein, could be considered as bacteriocin. The bacteriocin was independent of heat, and the inhibitory activity of which was kept over 90% after treated at pH 6. 5, 121 ℃ for 15 min. According to the characteristics of bacteria, the bacteriocin was classified into class Ⅱ a. The strain was identified and named Enterococcusfaecium BC-3 on the base of physiological and biochemical tests and 16S rRNA gene sequence homology analysis.%从自制的发酵肉、酸菜汁、黄瓜汁、大麦汁、玉米汁等以及市售鲜奶、传统干酪、红茶中分离出352株乳酸菌,通过琼脂平板扩散法筛选到l株对单核细胞增生李斯特菌和大肠杆菌有明显抑制作用的乳酸菌菌株.排除有机酸、过氧化氢等的干扰后,乳酸菌发酵液离心后的上清液仍有抑菌活性,用胰蛋白酶、胃蛋白酶、木瓜蛋白酶处理后失去抑菌活性,从而确定产生的抑菌物质具有蛋白质性质,是一种细菌素.该细菌素具有热稳定性,在pH6.5,121℃热处理15 min时,抑菌活性仍保持90%以上.经过生理生化试验和16S rRNA基因序列相似性分析,鉴定BC-3菌株为屎肠球菌,命名.Enterococcus.faecium BC-3.其产生的细菌素对单核细胞增生李斯特菌有特异活性,并且具有热稳定性,根据细菌素的分类特征,该细菌素属于Ⅱa类细菌素.

  4. 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...... of 31 indicator organisms representing various Gram-negative and positive pathogens. The screening showed that 3 Bacillus subtilis strains (B3, B122 and B222) in particular had antimicrobial activity against some Gram-positive organisms and were selected for further studies. It was found...... activity was detected during the stationary growth phase. The production of bacteriocin by B. subtilis B3, B122 and B222 was dependent on the aeration conditions. Maximum production of bacteriocin was observed under reduced aeration. Specific primers were used to screen isolates B3, B122 and B222 for genes...

  5. Bacteriocin production by Lactobacillus plantarum AMA-K isolated from Amasi, a Zimbabwean fermented milk product and study of the adsorption of bacteriocin AMA-K TO Listeria sp.

    Science.gov (United States)

    Todorov, Svetoslav D

    2008-01-01

    Bacteriocin AMA-K produced by Lactobacillus plantarum AMA-K inhibits the growth of Enterococcus spp., Escherichia coli, Klebsiella pneumoniae and Listeria spp. Growth of strain AMA-K in BHI, M17, soy milk and molasses was similar to growth in MRS. The effect of organic nitrogen sources, carbohydrates, glycerol, K2HPO4 and KH2PO4, MgSO4, MnSO4, tri-ammonium citrate, Tween 80, vitamins and initial pH on bacteriocin AMA-K was determined. The mode of action of bacteriocin AMA-K was studied. The effect of bacteriocin AMA-K to actively growing Listeria innocua LMG13568, L. ivanovii subsp. ivanovii ATCC19119 and L. monocytogenes ScottA was determined. Adsorption of bacteriocin AMA-K to target cells at different temperatures, pH and in presence of Tween 20, Tween 80, ascorbic acid, potassium sorbate, sodium nitrate and sodium chloride were studied. Bacteriocin AMA-K shares high homology to pediocin PA-1.

  6. Use of synthetic genes for cloning, production and functional expression of the bacteriocins enterocin A and bacteriocin E 50-52 by Pichia pastoris and Kluyveromyces lactis.

    Science.gov (United States)

    Jiménez, Juan J; Borrero, Juan; Gútiez, Loreto; Arbulu, Sara; Herranz, Carmen; Cintas, Luis M; Hernández, Pablo E

    2014-06-01

    The use of synthetic genes may constitute a successful approach for the heterologous production and functional expression of bacterial antimicrobial peptides (bacteriocins) by recombinant yeasts. In this work, synthetic genes with adapted codon usage designed from the mature amino acid sequence of the bacteriocin enterocin A (EntA), produced by Enterococcus faecium T136, and the mature bacteriocin E 50-52 (BacE50-52), produced by E. faecium NRRL B-32746, were synthesized. The synthetic entA and bacE50-52 were cloned into the protein expression vectors pPICZαA and pKLAC2 for transformation of derived vectors into Pichia pastoris X-33 and Kluyveromyces lactis GG799, respectively. The recombinant vectors were linearized and transformed into competent cells selecting for P. pastoris X-33EAS (entA), P. pastoris X-33BE50-52S (bacE50-52), K. lactis GG799EAS (entA), and K. lactis GG799BE50-52S (bacE50-52). P. pastoris X-33EAS and K. lactis GG799EAS, but not P. pastoris X-33BE50-52S and K. lactis GG799BE50-52S, showed antimicrobial activity in their supernatants. However, purification of the supernatants of the producer yeasts permitted recovery of the bacteriocins EntA and BacE50-52. Both purified bacteriocins were active against Gram-positive bacteria such as Listeria monocytogenes but not against Gram-negative bacteria, including Campylobacter jejuni.

  7. 新疆高寒牧区产细菌素低温乳酸菌的筛选%Screening of bacteriocin-producing low-temperature lactic acid bacteria in high, cold pasture areas in Xinjiang

    Institute of Scientific and Technical Information of China (English)

    王俊钢; 刘成江; 郭安民; 李宇辉; 韩冬印; 李开雄

    2013-01-01

    Forty-five lactic acid bacteria were screened from the samples collected from the high, cold pasture areas in Xinjiang, and three of them with antimicrobial properties were screened out through the test. After exclusion of organic acids and catalase, these three lactic acid bacteria still had a certain bacteriostasis performance. Meanwhile, the antibacterial activity was greatly reduced after treated with trypsin, which indicated that the metabolite was bacte-riocins, the protein with antibacterial property. These three lactic acid bacteria were identified to be: Lactobacillus plantarum, Lactobacillus pentosus and Lactococcus lactis, respectively.%从新疆高寒牧区牧民自制乳制品分离得到45株乳酸菌.采用排除有机酸和过氧化氢中和试验对分离的乳酸菌进行处理,结果表明三株乳酸菌有抑菌特性.用胰蛋白酶对发酵液进行处理后,其抑菌活性大大降低,说明代谢产物是具有蛋白属性的抑菌物质,判断为细菌素.鉴定结果初步认为,这三株乳酸菌分别属于植物乳杆菌、戊糖乳杆菌和乳酸乳球菌.

  8. The activity of bacteriocins from Carnobacterium maltaromaticum UAL307 against gram-negative bacteria in combination with EDTA treatment.

    Science.gov (United States)

    Martin-Visscher, Leah A; Yoganathan, Sabesan; Sit, Clarissa S; Lohans, Christopher T; Vederas, John C

    2011-04-01

    Bacteriocins from gram-positive bacteria are potent antimicrobial peptides that inhibit pathogenic and food-spoilage bacteria. They are usually ineffective against gram-negative bacteria because they cannot penetrate the outer membrane (OM). Disruption of the OM of some gram-negative bacteria was reported to sensitize them to certain bacteriocins. This study evaluates the activity of three purified bacteriocins [carnocyclin A (CclA), carnobacteriocin BM1 (CbnBM1) and piscicolin 126 (PisA)] produced by Carnobacterium maltaromaticum UAL307, which has been approved for preservation of food in United States and Canada, against three gram-negative bacteria (Escherichia coli DH5α, Pseudomonas aeruginosa ATCC 14207 and Salmonella Typhimurium ATCC 23564). Their efficacy is compared with bacteriocins of other classes: the lantibiotics nisin A (positive control) and gallidermin, and the cyclic peptide subtilosin A (SubA). In combination with EDTA, CclA inhibited both E. coli and Pseudomonas. PisA inhibited Pseudomonas, but CbnBM1 showed weak activity toward Pseudomonas. In comparison, nisin and gallidermin inhibited the growth of all three strains, whereas SubA was active against E. coli and Pseudomonas only at high concentrations. The results reveal that UAL307 bacteriocins can inhibit gram-negative bacteria if the OM is weakened, and that the different classes of bacteriocins in this study exert unique modes of action toward such bacteria.

  9. Development of Class IIa Bacteriocins as Therapeutic Agents

    OpenAIRE

    Lohans, Christopher T.; Vederas, John C.

    2012-01-01

    Class IIa bacteriocins have been primarily explored as natural food preservatives, but there is much interest in exploring the application of these peptides as therapeutic antimicrobial agents. Bacteriocins of this class possess antimicrobial activity against several important human pathogens. Therefore, the therapeutic development of these bacteriocins will be reviewed. Biological and chemical modifications to both stabilize and increase the potency of bacteriocins are discussed, as well as ...

  10. Novel mechanism of bacteriocin secretion and immunity carried out by lactococcal multidrug resistance proteins

    NARCIS (Netherlands)

    Gajic, O; Buist, G; Kojic, M; Topisirovic, L; Kuipers, OP; Kok, J

    2003-01-01

    A natural isolate of Lactococcus lactis was shown to produce two narrow spectrum class II bacteriocins, designated LsbA and LsbB. The cognate genes are located on a 5.6-kb plasmid within a gene cluster specifying LmrB, an ATP-binding cassette-type multidrug resistance transporter protein. LsbA is a

  11. Applications of Bacteriocins in Broiler Chickens to Reduce Carriage of Campylobacter and Salmonella

    Science.gov (United States)

    The paper will review studies which have used a variety of bacteriocins to treat Campylobacter jejuni and Salmonella enteritidis colonized broiler chickens. Antagonistic bacteria were chosen by selecting those isolates which produced zones of inhibition among confluent C. jejuni growth. From the...

  12. Novel mechanism of bacteriocin secretion and immunity carried out by lactococcal multidrug resistance proteins

    NARCIS (Netherlands)

    Gajic, O; Buist, G; Kojic, M; Topisirovic, L; Kuipers, OP; Kok, J

    2003-01-01

    A natural isolate of Lactococcus lactis was shown to produce two narrow spectrum class II bacteriocins, designated LsbA and LsbB. The cognate genes are located on a 5.6-kb plasmid within a gene cluster specifying LmrB, an ATP-binding cassette-type multidrug resistance transporter protein. LsbA is a

  13. 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 (Δψ

  14. 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

  15. 风干肠中戊糖片球菌所产细菌素L5-6的理化特性研究%A Study on Physicochemical Characteristics of Bacteriocin L5-6 Produced by Pediococcus Pentosaceus Isolated from Dried Cured Salami

    Institute of Scientific and Technical Information of China (English)

    张红星; 刘丽; 谢英; 郝彦玲

    2011-01-01

    Objective: In order to develop a kind of safe and effective food bio-preservative, the physicochemical characteristics of bacteriocin L5-6, produced by Pediococcus pentosaceus isolated from dried cured salami, was systematically studied. Methods: Inhibitory activity was analyzed by the well-diffusion method. The molecular weight of the bacteriocin was detected by Tricine-SDS-PAGE. Results: The anti-bacterial substance L5-6, which was found to be sensitive to proteolytic enzymes such as trypsin, proteinase K, and pronase E, was proved to be bacteriocin. Bacteriocin L5-6 had heat stability up to 100 ℃ (30min). Antibacterial activity still remained at pH from 2.0 to 10.0. Its maximum antibacterial activity was 2 560 AU during stationary phase (pH4.20) and the best harvesting time was 18h. Its mode of action was bactericidal with Listeria monocytogenes. Besides, it also exhibited the inhibition against gram-positive bacteria, such as Staphylococcus aureus, Lactobacillus plantarum, Lactobacillus delbrueckii subsp bulgaricus and gram-negative bacteria,such as Escherichia coli, Shigella, Salmonella. Tricine-SDS-PAGE showed that its molecular weight was about 4 kDa.Conclusions: Bacteriocin L5-6 was heat-stable (30 min at 100 ℃) and remained activity after incubation at pH from 2.0 to 10.0. It covered broad antimicrobial spectrum and could be degraded by proteases existing in the human body. Therefore, bacteriocin L5-6 had the potential prospect of application in the field of food preservation.%目的:对从风干肠中筛选的戊糖片球菌所产细茵素L5-6的理化特性进行系统研究,为开发安全高效的食品生物防腐剂奠定理论基础.方法:采用管碟法做抑菌试验,利用N-羟甲基甲基甘氨酸-SDS-PAGE电泳确定细茵素的相对分子质量.结果:抑菌物质L5-6时胰蛋白酶、蛋白酶K、链霉蛋白酶E敏感,证明此押菌物质为细菌素;细菌素L5-6在100℃30 min,pH 2~10的条件下具有极强的抑菌活性;当戊

  16. Temperature and pH conditions that prevail during fermentation of sausages are optimal for production of the antilisterial bacteriocin sakacin K.

    Science.gov (United States)

    Leroy, F; de Vuyst, L

    1999-03-01

    Sakacin K is an antilisterial bacteriocin produced by Lactobacillus sake CTC 494, a strain isolated from Spanish dry fermented sausages. The biokinetics of cell growth and bacteriocin production of L. sake CTC 494 in vitro during laboratory fermentations were investigated by making use of MRS broth. The data obtained from the fermentations was used to set up a predictive model to describe the influence of the physical factors temperature and pH on microbial behavior. The model was validated successfully for all components. However, the specific bacteriocin production rate seemed to have an upper limit. Both cell growth and bacteriocin activity were very much influenced by changes in temperature and pH. The production of biomass was closely related to bacteriocin activity, indicating primary metabolite kinetics, but was not the only factor of importance. Acidity dramatically influenced both the production and the inactivation of sakacin K; the optimal pH for cell growth did not correspond to the pH for maximal sakacin K activity. Furthermore, cells grew well at 35 degrees C but no bacteriocin production could be detected at this temperature. L. sake CTC 494 shows special promise for implementation as a novel bacteriocin-producing sausage starter culture with antilisterial properties, considering the fact that the temperature and acidity conditions that prevail during the fermentation process of dry fermented sausages are optimal for the production of sakacin K.

  17. 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

  18. 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.

  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

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    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. Encapsulation of Lactobacillus plantarum 423 and its Bacteriocin in Nanofibers.

    Science.gov (United States)

    Heunis, T D J; Botes, M; Dicks, L M T

    2010-03-01

    Plantaricin 423, produced by Lactobacillus plantarum 423, was encapsulated in nanofibers that were produced by the electrospinning of 18% (w/v) polyethylene oxide (200 000 Da). The average diameter of the nanofibers was 288 nm. Plantaricin 423 activity decreased from 51 200 AU/ml to 25 600 AU/ml and from 204 800 AU/ml to 51 200 AU/ml after electrospinning, as determined against Lactobacillus sakei DSM 20017 and Enterococcus faecium HKLHS, respectively. Cells of L. plantarum 423 encapsulated in nanofibers decreased from 2.3 × 10(10) cfu/ml before electrospinning to 4.7 × 10(8) cfu/ml thereafter. Cells entrapped in the nanofibers continued to produce plantaricin 423. This is the first report on the encapsulation of a bacteriocin and cells of L. plantarum in nanofibers. The method may be used to design a drug delivery system for bacteriocins and the encapsulation of probiotic lactic acid bacteria. The technology is currently being optimized.

  1. Production of Antilisterial Bacteriocins from Lactic Acid Bacteria in Dairy-Based Media: A Comparative Study.

    Science.gov (United States)

    Ünlü, Gülhan; Nielsen, Barbara; Ionita, Claudia

    2015-12-01

    One hundred and eight strains of lactic acid bacteria (LAB) were screened for bacteriocin production by the modified deferred antagonism and agar well diffusion methods. When the modified deferred antagonism method was employed, 82 LAB strains showed inhibitory action against Listeria monocytogenes v7 ½a, whereas 26 LAB strains expressed no inhibition. Only 12 LAB strains exhibited inhibitory activity when the agar well diffusion method was used, 11 of which had been previously recognized as bacteriocin production positive (Bac(+)). Lactobacillus viridescens NRRL B-1951 was determined, for the first time, to produce an inhibitory compound with a proteinaceous nature. The inhibitory activity was observed in the presence of lipase, α-chymotrypsin, and trypsin, but no inhibition zone could be detected in the presence of proteinase K, indicating the proteinaceous nature of the inhibitory compound. The inhibitory compound was active against Lact. sake ATCC 15521 and Lact. plantarum NCDO 995. Bacteriocin production by the Bac(+) LAB strains was assessed in Lactobacillus MRS Broth as well as in dairy-based media such as nonfat milk, demineralized whey powder, and cheddar cheese whey supplemented with complex nutrient sources that are rich in nitrogen. Lact. sake ATCC 15521 and L. monocytogenes CWD 1002, CWD 1092, CWD 1157, CWD 1198, and v7 ½a were used as indicators. The inhibitory activities of the bacteriocins varied depending on the indicator strains and the growth media used. The LAB indicator strains were found to be more sensitive to inhibition by bacteriocins when compared to the listerial indicator strains. Among the listerial indicators, L. monocytogenes CWD 1002 and CWD 1198 were the most sensitive strains to the bacteriocins investigated in this study. Media composition had a significant influence on bacteriocin production and activity. When compared to demineralized whey powder medium and cheddar cheese whey medium supplemented with whey protein concentrate

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

    Science.gov (United States)

    Nguyen, Chuong; Nguyen, Van Duy

    2016-01-01

    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.

  3. 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.

  4. Inhibition of Listeria monocytogenes growth by using combined bacteriocin-producing strains in raw beef%产抗菌素乳酸菌的组合应用对牛肉中李斯特菌污染的抑制作用研究

    Institute of Scientific and Technical Information of China (English)

    张佩华; 谷贵章; 张进杰; 陈健初

    2011-01-01

    The synergy inhibition of two lactic acid bacteria strains, Lactobacillus curvatus and Pediococcus acidilactici H,on the growth of Listeria monocytogenes in frozen beef was investigated. A Lactobacillus curvatus strain( producing the bacteriocin sakacin P)and a Pediococcus acidilactici H (producing bacteriocin pediocin AcH)were inoculated alone or together in a Listeria-seeded raw pork meat which was stored at 4℃ for 6 weeks.The growth of Listeria monocytogenes was controlled by adding either LAB strain alone,yet the rebound appeared after one-week storage. However,the time of inhibition was prolonged by adding combined these two LAB strains to 6 weeks, after when the Listeria monocytogenes had a rebound with the cfu count lower than 10cfu · g-1.Therefore, using the combined these two LAB strains can effectively delay the rebound of Listeria monocytogenes in the beef.%研究了弯曲乳酸杆菌和乳酸片球菌对低温冷藏牛肉中李斯特菌的混合协同抑制作用.李斯特菌、弯曲乳酸杆菌(产细菌素sakacin P)和乳酸片球菌(产生片球菌素AcH),单独或混合接种于冷鲜牛肉中,4℃下储藏6周.单一接种弯曲乳酸杆菌或乳酸片球菌均能对李斯特菌起到抑制作用,但一周后均出现李斯特菌再次污染现象;然而混合接种弯曲乳酸杆菌和乳酸片球菌能将对李斯特菌的抑制期延长至第六周,之后才出现反弹现象,且李斯特菌数低于10cfu·g-1.因此,应用组合产细菌素菌株能有效延长对李斯特菌的抑制作用.

  5. Screening of Broad-spectrum Bacteriocin-producing Lactic Acid Bacteria Strain and Characteristics of Antibacterial Compounds%1株产广谱细菌素乳酸菌的筛选及其抑菌物质的特性

    Institute of Scientific and Technical Information of China (English)

    曹珂珂; 王娣; 李妍

    2012-01-01

    By A broad spectrum bacteriocin producing strain was screened by plant punching and its antibacterial characteristics was studied. The results showed that one baeteriocin-producing Lactic acid bacteria strain isolated from plant materials exhibited strong inhibition activity against the E. coil. The supernatant of this strain could still inhibit the growth of indicator strain strongly after eliminating hydrogen peroxide and organic acid. After treatment with pep- sin, the strain' s inhibitory activity decreased sharply, which showed the inhibitory substance possessed the character- istic of protein, and it could be named bacterioein. The strain was identified as Laetobacillus plantarum through detec- tion of its appearance, physiological and biochemical characteristics. The inhibitory activity of strain fermentation su- pernatant was not affected by high temperature, 1% Tween-80, SDS, EDTA and the low pH. However, its inhibitory activity revealed an obvious decrease after treatment with protease K and trypsin than with pepsin. The bacterial inhi- bition spectrum showed that this was a kind of bacteriocin with wide inhibition soectrum.%从植物性材料中筛选到1株对大肠杆菌有明显抑制作用的乳酸菌,在排除有机酸和过氧化氢的干扰后,该菌株的发酵上清液仍有较强的抑菌性;胃蛋白酶处理后,抑菌活性明显降低,说明其抑菌物质为蛋白质类物质,是一种细菌素。通过形态学和生理生化分析,初步鉴定该菌株为植物乳杆菌。生物学特性研究表明,该菌株发酵上清液经高温、吐温-80、SDS、EDTA处理后,仍保持较好的抑菌活性;在酸性条件下稳定;对蛋白酶K和胰蛋白酶较胃蛋白酶敏感。抑菌谱显示,该菌株的发酵上清液具有广谱抑菌性。

  6. Isolation and Identification of a Bacillus Strain with Bacteriostatic Ability and Detection on Its Characters of Producing Bacteriocin%一株抑菌芽胞杆菌的分离鉴定及产细菌素性能检测

    Institute of Scientific and Technical Information of China (English)

    辛国芹; 徐海燕; 武香玉; 汪孟娟; 谢全喜; 谷巍

    2012-01-01

    A strain BX-6 with good bacteriostatic activity was isolated from fresh chicken manure by routine microbiological method. Based on the means of colony morphological characteristics, physiological and biochemical characteristics and 16S rDNA sequence phylogeny analysis, the strain was identified and classified. And the antimicrobial characters of bacteriocin produced by BX-6 was detected by cylinder-plate method. The results showed that strain BX-6 was identified as Bacillus subtilis. Some antibacterial substance of H202 was produced in the fermentation process of BX-6. The bacteriocin had a good thermal stability,pH tolerance and it was sensitive to most proteases. And it had better antibacterial effects on Salmonella pullorum C79-13 ,chicken Escherichia coil O1 and Staphylococcus aureus C56011. So it had the potential to be used as feed additive of livestock and poultry.%采用常规微生物学方法从新鲜鸡粪中分离得到1株抑菌效果较好的菌株BX-6。结合菌落形态特征、生理生化特性及菌株特异性序列分析等手段,确定其分类归属,并采用管碟法对所产细菌素的抑菌特性进行了检测。结果表明,菌株BX-6为枯草芽胞杆菌(Bacillus subtilis)。菌株在发酵过程中产生一定量的H2O2类抑菌物质,其所产细菌素具有较好的热稳定性、pH值耐受性,对大部分蛋白酶敏感,对鸡白痢沙门氏菌C79—13、鸡大肠杆菌01和金黄色葡萄球菌C56011有较好的抑菌效果,具有作为畜禽饲料添加剂的潜力。

  7. 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

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

    Science.gov (United States)

    Vijayakumar, Paul Priyesh; Muriana, Peter M

    2015-06-11

    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.

  9. Import of periplasmic bacteriocins targeting the murein.

    Science.gov (United States)

    Braun, Volkmar; Helbig, Stephanie; Patzer, Silke I

    2012-12-01

    Colicins are the only proteins imported by Escherichia coli and thus serve as tools to study the protein import mechanism. Most of the colicins studied degrade DNA, 16S RNA or tRNA in the cytoplasm, or form pores in the cytoplasmic membrane. Two bacteriocins, Cma (colicin M) and Pst (pesticin), affect the murein structure in the periplasm. These two bacteriocins must be imported only across the outer membrane and therefore represent the simplest system for studying protein import. Cma can be reversibly translocated across the outer membrane. Cma and Pst unfold during import. The crystal structure of Pst reveals a phage T4L (T4 lysozyme) fold of the activity domain. Both bacteriocins require energy for import which is translocated from the cytoplasmic membrane into the outer membrane by the Ton system. Cma kills cells only when the periplasmic FkpA PPIase (peptidylprolyl cis-trans isomerase)/chaperone is present.

  10. Bacteriocins active against plant pathogenic bacteria.

    Science.gov (United States)

    Grinter, Rhys; Milner, Joel; Walker, Daniel

    2012-12-01

    Gram-negative phytopathogens cause significant losses in a diverse range of economically important crop plants. The effectiveness of traditional countermeasures, such as the breeding and introduction of resistant cultivars, is often limited by the dearth of available sources of genetic resistance. An alternative strategy to reduce loss to specific bacterial phytopathogens is to use narrow-spectrum protein antibiotics such as colicin-like bacteriocins as biocontrol agents. A number of colicin-like bacteriocins active against phytopathogenic bacteria have been described previously as have strategies for their application to biocontrol. In the present paper, we discuss these strategies and our own recent work on the identification and characterization of candidate bacteriocins and how these potent and selective antimicrobial agents can be effectively applied to the control of economically important plant disease.

  11. Bacteriocins and other bioactive substances of probiotic lactobacilli as biological weapons against Neisseria gonorrhoeae.

    Science.gov (United States)

    Ruíz, Francisco O; Pascual, Liliana; Giordano, Walter; Barberis, Lucila

    2015-04-01

    In the search of new antimicrobial agents against Neisseria gonorrhoeae, the bacteriocins-producing probiotic lactobacilli deserve special attention. The inhibitory effects of biosubstances such as organic acids, hydrogen peroxide and each bacteriocin-like inhibitory substance (BLIS) L23 and L60 on the growth of different gonococcal strains were investigated. Different non-treated and treated cell-free supernatants of two probiotic lactobacilli containing these metabolites were used. The aims of this work were (i) to evaluate the antimicrobial activity of the biosubstances produced by two probiotic lactobacilli, estimating the proportion in which each of them is responsible for the inhibitory effect, (ii) to define their minimum inhibitory concentrations (MICs) and, (iii) to determine the potential interactions between these biosubstances against N. gonorrhoeae. The main antimicrobial metabolites were the BLIS-es L23 and L60 in comparison with other biosubstances. Proportionally, their contributions to the inhibition on the gonococcal growth were 87.28% and 80.66%, respectively. The MIC values of bacteriocins were promising since these substances, when diluted, showed considerable inhibitory activity for all gonococci. In the interaction between bacteriocins, 100% of synergism was found on the gonococcal growth. In summary, this study indicates that both L23 and L60 could potentially serve to design new bioproducts against N. gonorrhoeae.

  12. Genome mining demonstrates the widespread occurrence of gene clusters encoding bacteriocins in cyanobacteria.

    Science.gov (United States)

    Wang, Hao; Fewer, David P; Sivonen, Kaarina

    2011-01-01

    Cyanobacteria are a rich source of natural products with interesting biological activities. Many of these are peptides and the end products of a non-ribosomal pathway. However, several cyanobacterial peptide classes were recently shown to be produced through the proteolytic cleavage and post-translational modification of short precursor peptides. A new class of bacteriocins produced through the proteolytic cleavage and heterocyclization of precursor proteins was recently identified from marine cyanobacteria. Here we show the widespread occurrence of bacteriocin gene clusters in cyanobacteria through comparative analysis of 58 cyanobacterial genomes. A total of 145 bacteriocin gene clusters were discovered through genome mining. These clusters encoded 290 putative bacteriocin precursors. They ranged in length from 28 to 164 amino acids with very little sequence conservation of the core peptide. The gene clusters could be classified into seven groups according to their gene organization and domain composition. This classification is supported by phylogenetic analysis, which further indicated independent evolutionary trajectories of gene clusters in different groups. Our data suggests that cyanobacteria are a prolific source of low-molecular weight post-translationally modified peptides.

  13. Genome mining demonstrates the widespread occurrence of gene clusters encoding bacteriocins in cyanobacteria.

    Directory of Open Access Journals (Sweden)

    Hao Wang

    Full Text Available Cyanobacteria are a rich source of natural products with interesting biological activities. Many of these are peptides and the end products of a non-ribosomal pathway. However, several cyanobacterial peptide classes were recently shown to be produced through the proteolytic cleavage and post-translational modification of short precursor peptides. A new class of bacteriocins produced through the proteolytic cleavage and heterocyclization of precursor proteins was recently identified from marine cyanobacteria. Here we show the widespread occurrence of bacteriocin gene clusters in cyanobacteria through comparative analysis of 58 cyanobacterial genomes. A total of 145 bacteriocin gene clusters were discovered through genome mining. These clusters encoded 290 putative bacteriocin precursors. They ranged in length from 28 to 164 amino acids with very little sequence conservation of the core peptide. The gene clusters could be classified into seven groups according to their gene organization and domain composition. This classification is supported by phylogenetic analysis, which further indicated independent evolutionary trajectories of gene clusters in different groups. Our data suggests that cyanobacteria are a prolific source of low-molecular weight post-translationally modified peptides.

  14. Strategies for the use of bacteriocins in Gram-negative bacteria: relevance in food microbiology.

    Science.gov (United States)

    Prudêncio, Cláudia Vieira; Dos Santos, Miriam Teresinha; Vanetti, Maria Cristina Dantas

    2015-09-01

    Bacteriocins are ribosomally synthesized peptides that have bacteriostatic or bactericidal effects on other bacteria. The use of bacteriocins has emerged as an important strategy to increase food security and to minimize the incidence of foodborne diseases, due to its minimal impact on the nutritional and sensory properties of food products. Gram-negative bacteria are naturally resistant to the action of bacteriocins produced by Gram-positive bacteria, which are widely explored in foods. However, these microorganisms can be sensitized by mild treatments, such as the use of chelating agents, by treatment with plant essential oils or by physical treatments such as heating, freezing or high pressure processing. This sensitization is important in food microbiology, because most pathogens that cause foodborne diseases are Gram-negative bacteria. However, the effectiveness of these treatments is influenced by several factors, such as pH, temperature, the composition of the food and target microbiota. In this review, we comment on the main methods used for the sensitization of Gram-negative bacteria, especially Salmonella, to improve the action of bacteriocins produced by Gram-positive bacteria.

  15. Evidence for production of a bacteriocin-like substance by Staphylococcus pseudintermedius, inhibitory to Staphylococcus aureus from foods.

    Science.gov (United States)

    Pinto, Taiz Siqueira; de Oliveira, Cybelle Pereira; da Costa, Ana Carolina Vieira; Lima, Catiana Oliveira; Barreto, Humberto Medeiros; de Souza, Evandro Leite; Siqueira-Junior, José Pinto

    2013-01-01

    This study assessed the production of a bacteriocin-like substance by Staphylococcus pseudintermedius S28, and evaluates its inhibitory effect against isolates of S. aureus from foods. All indicator isolates were sensitive to the substance produced from S. pseudintermedius S28, showing growth inhibition zones ranging from 14.2 to 28.3 mm. The inhibitory substance has no effect against the producer strain. The inhibitory substance was affected by proteolytic enzymes, while glycolytic and lipolytic enzymes had no effect, suggesting that the active substance could be considered as a bacteriocin-like substance. From these results, S. pseudintermedius S28 could be an interesting producer of a bacteriocin-like substance capable of strongly inhibiting S. aureus.

  16. Applications of the bacteriocin, nisin.

    Science.gov (United States)

    Delves-Broughton, J; Blackburn, P; Evans, R J; Hugenholtz, J

    1996-02-01

    Nisin was first introduced commercially as a food preservative in the UK approximately 30 years ago. First established use was as a preservative in processed cheese products and since then numerous other applications in foods and beverages have been identified. It is currently recognised as a safe food preservative in approximately 50 countries. The established uses of nisin as a preservative in processed cheese, various pasteurised dairy products, and canned vegetables will be briefly reviewed. More recent applications of nisin include its use as a preservative in high moisture, hot baked flour products (crumpets) and pasteurised liquid egg. Renewed interest is evident in the use of nisin in natural cheese production. Considerable research has been carried out on the antilisterial properties of nisin in foods and a number of applications have been proposed. Uses of nisin to control spoilage lactic acid bacteria have been identified in beer, wine, alcohol production and low pH foods such as salad dressings. Further developments of nisin are likely to include synergistic action of nisin with chelators and other bacteriocins, and its use as an adjunct in novel food processing technology such as higher pressure sterilisation and electroporation. Production of highly purified nisin preparations and enhancement by chelators has led to interest in the use of nisin for human ulcer therapy, and mastitis control in cattle.

  17. Class IIa Bacteriocins: Diversity and New Developments

    Directory of Open Access Journals (Sweden)

    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.

  18. Class IIa bacteriocins: diversity and new developments.

    Science.gov (United States)

    Cui, Yanhua; Zhang, Chao; Wang, Yunfeng; Shi, John; Zhang, Lanwei; Ding, Zhongqing; Qu, Xiaojun; Cui, Hongyu

    2012-12-06

    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.

  19. Class IIa Bacteriocins: Diversity and New Developments

    Science.gov (United States)

    Cui, Yanhua; Zhang, Chao; Wang, Yunfeng; Shi, John; Zhang, Lanwei; Ding, Zhongqing; Qu, Xiaojun; Cui, Hongyu

    2012-01-01

    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. PMID:23222636

  20. 西藏地区发酵牛乳中产细菌素乳酸菌的筛选及鉴定%Screening and Identification of Bacteriocin-producing Lactic Acid Bacteria from Tibet Fermented Milk Products

    Institute of Scientific and Technical Information of China (English)

    陈芝兰; 田发益; 何建清; 杨爽; 李晓卫; 杨吉霞

    2012-01-01

    从西藏地区藏族传统发酵乳中分离乳酸菌,采用生理生化特性和16S基因序列同源性分析对其进行鉴定,通过双层琼脂平板扩散法筛选具有抑菌活性的菌株。结果表明,共分离37株乳酸菌,其中,乳杆菌属(Lacto-bacillus)35株、明串珠菌属(Leuconostoc)2株;35株乳酸杆菌为Lactobacilluscasei16株、Lactobacillusparacasei7株、Lactobacillusplantarum4株、Lactobacillusfermentum2株、L.delbrueckilsubsp.bulgaricus2株、Lactobacillushelveti—CUS1株、Lactobacillusdiolivorans3株;7株L.casei和L.paracasei的发酵上清液对3株细菌指示菌表现出明显抑制作用,所有菌株对真菌无抑菌活性;在排除有机酸、H2O2等的干扰和经蛋白酶K处理后,初步确定7株乳酸菌发酵上清液中的抑菌物质为细菌素。%Thirty seven lactic acid bacterial strains were isolated from Tibet traditional fermented milk products, and were identified to species level through physiological and biochemical characterization, as well as 16S rRNA se- quence analysis method. The result showed that out of 39 isolates, 37 were assigned to lactobacillus genus, including Lactobacillus casei ( 16 ), Lactobacillus paracasei (7), Lactobacillus plantarum (4), Lactobacillus fermentum (2), L. delbrueckii subsp, bulgaricus (2) , LactobaciUus helveticus ( 1 ) , and Lactobacillus diolivorans (3). Two strains were assigned to Leuconostoc genus. Cell free supernatant of seven L. casei and L. paracasei strains showed significant an- timicrobial activity against 3 indicator pathogenic bacteria. All isolated strains had no antimicrobial activity against fungi. The possibility of organic acid or H2O2 action as antimicrobial components was eliminated by experiments. The antimicrobial components were inferred to be bacteriocin because the antimicrobial activity disappeared after cell free supernatant was treated with Droteinase.

  1. Biochemical characterisation and genetic analysis of aureocin A53, a new, atypical bacteriocin from Staphylococcus aureus.

    Science.gov (United States)

    Netz, Daili Jacqueline Aguilar; Pohl, Regula; Beck-Sickinger, Annette G; Selmer, Thorsten; Pierik, Antonio J; Bastos, Maria do Carmo de Freire; Sahl, Hans-Georg

    2002-06-07

    Aureocin A53 is produced by Staphylococcus aureus A53. It is encoded on a 10.4 kb plasmid, pRJ9, and is active against Listeria monocytogenes. Aureocin A53 is a highly cationic 51-residue peptide containing ten lysine and five tryptophan residues. Aureocin A53 was purified to homogeneity by hydrophobic-interaction, cation-exchange, and reverse-phase chromatography. MALDI-TOF mass spectrometry yielded a molecular mass of 6012.5 Da, which was 28 Da higher than predicted from the structural gene sequence of the bacteriocin. The mass increment resulted from an N-formylmethionine residue, indicating that the aureocin A53 is synthesised and secreted without a typical bacteriocin leader sequence or sec-dependent signal peptide. The structural identity of aureocin A53 was verified by Edman sequencing after de-blocking with cyanogen bromide and extensive mass spectrometry analysis of enzymatically and laser-generated fragments. The complete sequence of pRJ9 was determined and none of the open reading frames identified in the vicinity of the structural gene aucA showed similarity to genes that are typically found in bacteriocin gene clusters. Thus, neither a dedicated protease or transporter, nor modifying enzymes and regulatory elements seemed to be involved in the production of aureocin A53. Further unique features that distinguish aureocin A53 from other peptide bacteriocins include remarkable protease stability and a defined, rigid structure in aqueous solution.

  2. 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.

  3. 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.

  4. New bacteriocin from Bacillus clausii strainGM17: purification, characterization, and biological activity.

    Science.gov (United States)

    Mouloud, Ghadbane; Daoud, Harzallah; Bassem, Jaouadi; Laribi Atef, Ibn; Hani, Belhadj

    2013-12-01

    A bacteriocin-producing strain (9,000 AU/ml) was isolated from the rhizosphere of Algerian healthy plants Ononis angustissima Lam. and identified as Bacillus clausii strain GM17. The bacteriocin, called Bac-GM17, was purified from the culture supernatant after heat treatment, ammonium sulfate precipitation, Sephadex G-50 chromatography and Mono Q fast-performance liquid chromatography (FPLC). Based on matrix-assisted laser desorption ionization-time of flight mass spectrometry analysis, the purified Bac-GM17 is a monomer protein with a molecular mass of 5,158.11 Da. The N-terminal sequencing allowed for the straightforward identification of its first 20 residues, which were of pure bacteriocin. It also revealed that this bacteriocin contained a unique sequence, namely DWTCSKWSCLVCDDCSVELT, which suggests the identification of a novel compound. Bac-GM17 was extremely heat stable (20 min at 120 °C) and was stable within the pH range (3-9). It was found to be resistant to the proteolytic action of trypsin, pepsin, papain, pronase E, and proteinase K. It was also noted to display a bactericidal mode of action against Agrobacterium tumefaciens C58 and a fungistatic mode of action against Candida tropicalis R2 CIP203.

  5. 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

    1992-01-01

    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 operon

  6. Nuclear Magnetic Resonance Solution Structures of Lacticin Q and Aureocin A53 Reveal a Structural Motif Conserved among Leaderless Bacteriocins with Broad-Spectrum Activity.

    Science.gov (United States)

    Acedo, Jeella Z; van Belkum, Marco J; Lohans, Christopher T; Towle, Kaitlyn M; Miskolzie, Mark; Vederas, John C

    2016-02-02

    Lacticin Q (LnqQ) and aureocin A53 (AucA) are leaderless bacteriocins from Lactococcus lactis QU5 and Staphylococcus aureus A53, respectively. These bacteriocins are characterized by the absence of an N-terminal leader sequence and are active against a broad range of Gram-positive bacteria. LnqQ and AucA consist of 53 and 51 amino acids, respectively, and have 47% identical sequences. In this study, their three-dimensional structures were elucidated using solution nuclear magnetic resonance and were shown to consist of four α-helices that assume a very similar compact, globular overall fold (root-mean-square deviation of 1.7 Å) with a highly cationic surface and a hydrophobic core. The structures of LnqQ and AucA resemble the shorter two-component leaderless bacteriocins, enterocins 7A and 7B, despite having low levels of sequence identity. Homology modeling revealed that the observed structural motif may be shared among leaderless bacteriocins with broad-spectrum activity against Gram-positive organisms. The elucidated structures of LnqQ and AucA also exhibit some resemblance to circular bacteriocins. Despite their similar overall fold, inhibition studies showed that LnqQ and AucA have different antimicrobial potency against the Gram-positive strains tested, suggesting that sequence disparities play a crucial role in their mechanisms of action.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Circular Updates

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Circular Updates are periodic sequentially numbered instructions to debriefing staff and observers informing them of changes or additions to scientific and specimen...

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

    Directory of Open Access Journals (Sweden)

    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.

  10. Bacteriocin as Weapons in the Marine Animal-Associated Bacteria Warfare: Inventory and Potential Applications as an Aquaculture Probiotic

    Directory of Open Access Journals (Sweden)

    Florie Desriac

    2010-04-01

    Full Text Available As the association of marine animals with bacteria has become more commonly recognized, researchers have increasingly questioned whether these animals actually produce many of the bioactive compounds originally isolated from them. Bacteriocins, ribosomally synthesized antibiotic peptides, constitute one of the most potent weapons to fight against pathogen infections. Indeed, bacteriocinogenic bacteria may prevent pathogen dissemination by occupying the same ecological niche. Bacteriocinogenic strains associated with marine animals are a relevant source for isolation of probiotics. This review draws up an inventory of the marine bacteriocinogenic strains isolated from animal-associated microbial communities, known to date. Bacteriocin-like inhibitory substances (BLIS and fully-characterized bacteriocins are described. Finally, their applications as probiotics in aquaculture are discussed.

  11. Bacteriocin as Weapons in the Marine Animal-Associated Bacteria Warfare: Inventory and Potential Applications as an Aquaculture Probiotic

    Science.gov (United States)

    Desriac, Florie; Defer, Diane; Bourgougnon, Nathalie; Brillet, Benjamin; Le Chevalier, Patrick; Fleury, Yannick

    2010-01-01

    As the association of marine animals with bacteria has become more commonly recognized, researchers have increasingly questioned whether these animals actually produce many of the bioactive compounds originally isolated from them. Bacteriocins, ribosomally synthesized antibiotic peptides, constitute one of the most potent weapons to fight against pathogen infections. Indeed, bacteriocinogenic bacteria may prevent pathogen dissemination by occupying the same ecological niche. Bacteriocinogenic strains associated with marine animals are a relevant source for isolation of probiotics. This review draws up an inventory of the marine bacteriocinogenic strains isolated from animal-associated microbial communities, known to date. Bacteriocin-like inhibitory substances (BLIS) and fully-characterized bacteriocins are described. Finally, their applications as probiotics in aquaculture are discussed. PMID:20479972

  12. 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

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

    Science.gov (United States)

    Budde, Birgitte Bjørn; Hornbaek, Tina; Jacobsen, Tomas; Barkholt, Vibeke; Koch, Anette Granly

    2003-06-15

    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-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 activity without producing any undesirable flavour components in meat products. For identification of the bacteriocins produced, partial purification was carried out by ammonium sulphate precipitation, dialysis, and cation exchange chromatography. SDS-PAGE analysis revealed two bands with inhibitory activity corresponding to molecular sizes of 4.6 and 5.3 kDa. N-terminal amino acid sequencing showed that Leuc. carnosum 4010 produced two bacteriocins highly similar or identical to leucocin A and leucocin C. Application experiments showed that the addition of 10(7) cfu/g Leuc. carnosum 4010 to a 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 degrees C 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.

  14. Application of anti-listerial bacteriocins: monitoring enterocin expression by multiplex relative reverse transcription-PCR.

    Science.gov (United States)

    Williams, D Ross; Chanos, Panagiotis

    2012-12-01

    Listeriosis is a deadly food-borne disease, and its incidence may be limited through the biotechnological exploitation of a number of anti-listerial biocontrol agents. The most widely used of these agents are bacteriocins and the Class II enterocins are characterized by their activity against Listeria. Enterocins are primarily produced by enterococci, particularly Enterococcus faecium and many strains have been described, often encoding multiple bacteriocins. The use of these strains in food will require that they are free of virulence functions and that they exhibit a high level expression of anti-listerial enterocins in fermentation conditions. Multiplex relative RT (reverse transcription)-PCR is a technique that is useful in the discovery of advantageous expression characteristics among enterocin-producing strains. It allows the levels of individual enterocin gene expression to be monitored and determination of how expression is altered under different growth conditions.

  15. Quantitative profiling of bacteriocins present in dairy-free probiotic preparations of Lactobacillus acidophilus by nanoliquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Nandakumar, Renu; Talapatra, Kesh

    2014-01-01

    Bacteriocins are a heterogeneous group of ribosomally synthesized peptides or proteins with antimicrobial activity, produced predominantly by lactic acid bacteria, with potential applications as biopreservatives and probiotics. We describe here a novel strategy based on a bottom-up, shotgun proteomic approach using nanoliquid chromatography-tandem mass spectrometry (nanoLC-MS/MS) with multiple fragmentation techniques for the quantitative profiling of bacteriocins present in the probiotic preparations of Lactobacillus acidophilus. A direct LC-MS/MS analysis with alternate collision-induced dissociation, high-energy collision dissociation, and electron-transfer dissociation fragmentation following a filter-assisted size-exclusion sample prefractionation has resulted in the identification of peptides belonging to 37 bacteriocins or related proteins. Peptides from lactacin F, helveticin J, lysin, avicin A, acidocin M, curvaticin FS47, and carocin D were predominant. The process of freeze drying under vacuum was observed to affect both the diversity and abundance of bacteriocins. Data acquisition using alternating complementary peptide fragmentation modes, especially electron-transfer dissociation, has significantly enhanced the peptide sequence coverage and number of bacteriocin peptides identified. Multi-enzyme proteolytic digestion was observed to increase the sample complexity and dynamic range, lowering the chances of detection of low-abundant bacteriocin peptides by LC-MS/MS. An analytical platform integrating size exclusion prefractionation, nanoLC-MS/MS analysis with multiple fragmentation techniques, and data-dependent decision tree-driven bioinformatic data analysis is novel in bacteriocin research and suitable for the comprehensive bioanalysis of diverse, low-abundant bacteriocins in complex samples.

  16. Operational Circulars

    CERN Multimedia

    2003-01-01

    Operational Circular N° 4 - April 2003 Conditions for use by members of the CERN personnel of vehicles belonging to or rented by CERN - This circular has been drawn up. Operational Circular N° 5 - October 2000 Use of CERN computing facilities - Further details on the personal use of CERN computing facilities Operational Circular N° 5 and its Subsidiary Rules http://cern.ch/ComputingRules defines the rules for the use of CERN computing facilities. One of the basic principles governing such use is that it must come within the professional duties of the user concerned, as defined by the user's divisional hierarchy. However, personal use of the computing facilities is tolerated or allowed provided : a) It is in compliance with Operational Circular N° 5 and not detrimental to official duties, including those of other users; b) the frequency and duration is limited and there is a negligible use of CERN resources; c) it does not constitute a political, commercial and/or profit-making activity; d) it is not...

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

    Directory of Open Access Journals (Sweden)

    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.

  18. Antiviral potential of lactic acid bacteria and their bacteriocins.

    Science.gov (United States)

    Al Kassaa, I; Hober, D; Hamze, M; Chihib, N E; Drider, D

    2014-12-01

    Emerging resistance to antiviral agents is a growing public health concern worldwide as it was reported for respiratory, sexually transmitted and enteric viruses. Therefore, there is a growing demand for new, unconventional antiviral agents which may serve as an alternative to the currently used drugs. Meanwhile, published literature continues shedding the light on the potency of lactic acid bacteria (LAB) and their bacteriocins as antiviral agents. Health-promoting LAB probiotics may exert their antiviral activity by (1) direct probiotic-virus interaction; (2) production of antiviral inhibitory metabolites; and/or (3) via stimulation of the immune system. The aim of this review was to highlight the antiviral activity of LAB and substances they produce with antiviral activity.

  19. The sactibiotic subclass of bacteriocins: an update.

    Science.gov (United States)

    Mathur, Harsh; Rea, Mary C; Cotter, Paul D; Hill, Colin; Ross, R Paul

    2015-01-01

    The sactibiotics are a recently designated subclass of bacteriocins that contain characteristic cysteine sulphur to α -carbon linkages mediated through post-translational modifications. They are a relatively small subclass of bacteriocins compared to the most thoroughly studied lantibiotics. The sactibiotics that have been extensively studied thus far are thuricin CD, subtilosin A, thurincin H, and propionicin F. Despite their recent discovery, there have already been significant advances made in the study of sactibiotics, most notably the discovery of the narrow spectrum anti-Clostridium difficile sactibiotic, thuricin CD. In addition, scientists have gained insights into the mechanisms of action of the sactibiotic subtilosin A, which targets Listeria monocytogenes,Gardnerella vaginalis, and other pathogens. Also, the development of heterologous host systems and homologous expression and site-directed mutagenesis systems for the sactibiotic thurincin H have opened up many opportunities for further studies on this sactibiotic. These and other recent studies concerning the molecular biology, 3D structural elucidation, mode of action, self-protection mechanisms, and antimicrobial spectrum of the sactibiotic subgroup of bacteriocins are discussed in this review.

  20. Characterization of anti-Listeria bacteriocins isolated from shellfish: potential antimicrobials to control non-fermented seafood.

    Science.gov (United States)

    Pinto, Ana Luísa; Fernandes, Melissa; Pinto, Cristina; Albano, Helena; Castilho, Fernanda; Teixeira, Paula; Gibbs, Paul A

    2009-01-31

    This work had as main objectives to characterize two bacteriocins produced by lactic acid bacteria (LAB) previously isolated from non-fermented seafood, in order to evaluate their potential as new food protective agents. The two bacteriocinogenic isolates were identified by Polymerase Chain Reaction (PCR) using genus- and species-specific primers, and confirmed by 16S rDNA sequencing, as Enterococcus faecium and Pediococcus pentosaceus. The antimicrobial spectrum of each strain included several indicator microorganisms, some of them also isolated from seafood. Growth of Listeria innocua, L. monocytogenes, Staphylococcus aureus, Bacillus cereus and other LAB species were inhibited, although no inhibition of Gram-negative microorganisms was observed. Proteolytic, but not lipolytic or glycolytic enzymes, completely inactivated the antimicrobial effect of both cell-free supernatants confirming the proteinaceous nature of the inhibitors. The antimicrobial activity was maintained after treatment with NaCl, SDS, Triton X-100, Tween 20, Tween 80 and EDTA after 2 h or 5 h of exposure and both bacteriocins were stable over a wide range of pH and temperatures. Production of bacteriocin by E. faecium (bacALP7) was detected initially at exponential phase and reached a maximum activity of 25,600 AU/ml in the early stationary phase, whereas bacteriocin production by P. pentosaceus ALP57 (bacALP57) reached the maximum at exponential phase with 12,800 AU/ml. The bacteriocins did not kill L. monocytogenes ESB54 nor L. innocua 2030c however, cellular growth was reduced. The partially purified bacteriocins, bacALP7 and bacALP57, were below 6.5 kDa in size as determined by Tricine-SDS gel electrophoresis. E. faecium and P. pentosaceus contained DNA fragments corresponding in size to those recorded for enterocin B and pediocin PA-1, respectively. Sequencing of the fragments from both bacteriocins confirmed the homology. To our knowledge, for the first time two LAB producing bacteriocins

  1. Screening of marine bacteria with bacteriocin-like activities and probiotic potential for ornate spiny lobster (Panulirus ornatus) juveniles.

    Science.gov (United States)

    Nguyen, Van Duy; Pham, Thu Thuy; Nguyen, Thi Hai Thanh; Nguyen, Thi Thanh Xuan; Hoj, Lone

    2014-09-01

    Bacteriocins are ribosomally synthesized antimicrobial peptides, which have been found in diverse bacterial species of terrestrial origins and some from the sea. New bacteriocins with new characteristics, new origins and new applications are likely still awaiting discovery. The present study screened bacteria isolated from marine animals of interest to the aquaculture industry for antimicrobial and bacteriocin-like activities in order to uncover biodiversity of bacteriocin producers, and explore the potential application in aquaculture. In total, 24 of 100 screened isolates showed antimicrobial activities and 7 of these exerted bacteriocin-like activities. Sequencing of 16S rRNA genes identified the isolates as members of the six genera Proteus, Providencia, Klebsiella, Alcaligenes, Bacillus and Enterococcus. In some cases, further analysis of housekeeping genes, rpoB for Proteus and recA for Klebsiella, as well as biochemical tests was necessary for identification to species level, and some of the Proteus isolates may represent novel species. The seven bacteriocinogenic isolates showed a wide antimicrobial spectrum against foodborne and animal pathogens, which opens the way to their potential use as marine drugs and probiotics in food, aquaculture, livestock and clinical settings. As a case study, the protective effect of shortlisted bacteriocinogenic isolates were tested in aquaculture-raised spiny lobster (Panulirus ornatus) juveniles. A single-strain (Bacillus pumilus B3.10.2B) and a three-strain (B. pumilus B3.10.2B, Bacillus cereus D9, Lactobacillus plantarum T13) probiotic preparation were added to the feed of Panulirus ornatus juveniles, which were subsequently challenged with the pathogen Vibrio owensii DY05. Juveniles in the probiotic treatments displayed increased growth and reduced feed conversion rates after 60 days, and increased survival rate after pathogen challenge relative to the control. This study represents the first evidence of bacteriocin

  2. Characterization of Xanthomonas spp. strains by bacteriocins Caracterização de isolados de Xanthomonas spp. por bacterocinas

    Directory of Open Access Journals (Sweden)

    Marcel Bonini

    2007-03-01

    Full Text Available Twenty-five strains of Xanthomonas axonopodis pv. citri and 14 strains of Xanthomonas spp. were tested for bacteriocin production. X. axonopodis pv. passiflorae strains were sensitive to the bacteriocins produced by the 25 X. axonopodis pv. citri strains evaluated in this study while strains of X. axonopodis pv. manihotis and X. campestris pv. campestris showed variable sensitivity. Only five of the 25 X. axonopodis pv. citri strains were not inhibited by the bacteriocins produced by the two X. axonopodis pv. passiflorae strains. The bacteriocins produced by the Xanthomonas axonopodis pv. citri (FDC-806 and X. axonopodis pv. passiflorae (Mar-2850 A strains were thermolabile, resistant to lysozyme and sensitive to DNAse. The bacteriocin produced by X. axonopodis pv. passiflorae was resistant to the action of proteinase K, trypsin and RNAse while the bacteriocin produced by X. axonopodis pv. citri was sensitive to these enzymes. The bacteriocins produced by X. axonopodis pv. passiflorae and X. axonopodis pv. citri were called passifloricin and citricin, respectively.Vinte e cinco isolados de Xanthomonas axonopodis pv. citri e 14 isolados de Xanthomonas spp. foram comparados a fim de verificar a capacidade de produção de bacteriocina e a sua sensibilidade. Isolados de X. axonopodis pv. passiflorae foram sensíveis às bacteriocinas produzidas por 25 isolados de X. axonopodis pv. citri avaliados e os isolados de X. axonopodis pv. manihotis e X. campestris pv. campestris apresentaram sensibilidade variável. Dos 25 isolados de X. axonopodis pv. citri apenas cinco não foram inibidos pelas bacteriocinas produzidas por dois isolados de X. axonopodis pv. passiflorae. As bacteriocinas produzidas pelos isolados de X. axonopodis pv. citri (FDC-806 e de X. axonopodis pv. passiflorae (Mar-2850 A foram termolábeis e resistentes à lisozima e sensíveis a DNAse. A bacteriocina produzida pelo isolado de X. axonopodis pv. passiflorae foi resistente à a

  3. 一株从酸菜中分离的产细菌素乳杆菌的鉴定及其所产抑菌物质的研究%Identification and study on bacteriocin-producing Lactobacillus screened from Sauerkraut

    Institute of Scientific and Technical Information of China (English)

    牛爱地; 韩建春

    2009-01-01

    A lactic acid bacteria A_5 strain was isolated from the sauerkraut. The results showed that the supernatant of A_5 strain was sensitive with pepsin and papain, the inhibitory material of A_5 strain was a kind of protein, which could be classed as bacteriocin. The bacteriocin had the strong heat endurance, and it still had the strong bacteriostatic activity at 121 ℃, 20 min. The bacteriocin had the strong bacteriostatic activity in pH 3.0-5.0. The bacteriocin showed inhibition to some gram-positive and gram-negative bacteria. Therefore, it was a kind of bacteriocin with broad-spectrum antimicrobial activity.%从酸菜汁中分离出一株有抑菌活性的菌株,经鉴定为乳杆菌A_5.温度、pH对菌株发酵上清液的影响以及发酵上清液对酶的敏感性的研究表明,发酵上清液中的抑菌物质对胃蛋白酶、木瓜蛋白酶较敏感,说明抑菌物质是一种蛋白质,确定为细菌素.该细菌素具有良好的热稳定性,在121℃20 min的高温条件下,仍具有较强的抑菌活性.菌株所产细菌素在酸性条件下有较强的抑菌活性(pH 3.0~5.0);菌株产生的细菌素可以较好地抑制革兰氏阳性、阴性菌,表明菌株所产细菌素是一类具有广谱抑菌活性的细菌素.

  4. Circular RNAs

    DEFF Research Database (Denmark)

    Han, Yi-Neng; Xia, Shengqiang; Zhang, Yuan-Yuan

    2017-01-01

    Circular RNAs (circRNAs) are a novel type of universal and diverse endogenous noncoding RNAs (ncRNAs) and they form a covalently closed continuous loop without 5' or 3' tails unlike linear RNAs. Most circRNAs are presented with characteristics of abundance, stability, conservatism, and often exhi...

  5. Bacteriocin production by Lactobacillus plantarum AMA-K isolated from Amasi, a Zimbabwean fermented milk product and study of the adsorption of bacteriocin AMA-K to Listeria sp. Otimização da produção de bacteriocina por Lactobacillus plantarum AMA-K isolado de Amasi, um produto lácteo fermentado de Zimbabwe, e estudo da adsorção da bacteriocina AMA-K à Listeria innocua, Listeria monocytogenes e Listeria ivanovii subsp. ivanovii

    OpenAIRE

    Svetoslav D. Todorov

    2008-01-01

    Bacteriocin AMA-K produced by Lactobacillus plantarum AMA-K inhibits the growth of Enterococcus spp., Escherichia coli, Klebsiella pneumoniae and Listeria spp. Growth of strain AMA-K in BHI, M17, soy milk and molasses was similar to growth in MRS. The effect of organic nitrogen sources, carbohydrates, glycerol, K2HPO4 and KH2PO4, MgSO4, MnSO4, tri-ammonium citrate, Tween 80, vitamins and initial pH on bacteriocin AMA-K was determined. The mode of action of bacteriocin AMA-K was studied. The e...

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

    Directory of Open Access Journals (Sweden)

    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.

  7. 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.

  8. Bacteriocins reduce Campylobacter jejuni colonization while bacteria producing bacteriocins are ineffective

    Science.gov (United States)

    Broiler chickens are widely considered an important source for human exposure to Campylobacter jejuni because of the high numbers found colonizing the chicken gut and the consequent contamination of processed carcasses. We hoped to intervene in gut colonization by C. jejuni using a defined probioti...

  9. Purification and Characterization of a Novel Cold Shock Protein-Like Bacteriocin Synthesized by Bacillus thuringiensis

    Science.gov (United States)

    Huang, Tianpei; Zhang, Xiaojuan; Pan, Jieru; Su, Xiaoyu; Jin, Xin; Guan, Xiong

    2016-01-01

    Bacillus thuringiensis (Bt), one of the most successful biopesticides, may expand its potential by producing bacteriocins (thuricins). The aim of this study was to investigate the antimicrobial potential of a novel Bt bacteriocin, thuricin BtCspB, produced by Bt BRC-ZYR2. The results showed that this bacteriocin has a high similarity with cold-shock protein B (CspB). BtCspB lost its activity after proteinase K treatment; however it was active at 60 °C for 30 min and was stable in the pH range 5–7. The partial loss of activity after the treatments of lipase II and catalase were likely due to the change in BtCspB structure and the partial degradation of BtCspB, respectively. The loss of activity at high temperatures and the activity variation at different pHs were not due to degradation or large conformational change. BtCspB did not inhibit four probiotics. It was only active against B. cereus strains 0938 and ATCC 10987 with MIC values of 3.125 μg/mL and 0.781 μg/mL, and MBC values of 12.5 μg/mL and 6.25 μg/mL, respectively. Taken together, these results provide new insights into a novel cold shock protein-like bacteriocin, BtCspB, which displayed promise for its use in food preservation and treatment of B. cereus-associated diseases. PMID:27762322

  10. Active polymers containing Lactobacillus curvatus CRL705 bacteriocins: effectiveness assessment in Wieners.

    Science.gov (United States)

    Blanco Massani, M; Molina, V; Sanchez, M; Renaud, V; Eisenberg, P; Vignolo, G

    2014-05-16

    Bacteriocins from lactic acid bacteria have potential as natural food preservatives. In this study two active (synthetic and gluten) films were obtained by the incorporation of lactocin 705 and lactocin AL705, bacteriocins produced by Lactobacillus curvatus CRL705 with antimicrobial activity against spoilage lactic acid bacteria and Listeria. Antimicrobial film effectiveness was determined in Wieners inoculated with Lactobacillus plantarum CRL691 and Listeria innocua 7 (10(4)CFU/g) stored at 5°C during 45days. Active and control (absence of bacteriocins) packages were prepared and bacterial counts in selective media were carried out. Visual inspection and pH measurement of Wieners were also performed. Typical growth of both inoculated microorganisms was observed in control packages which reached 10(6)-10(7)CFU/g at the end of storage period. In the active packages, L. innocua 7 was effectively inhibited (2.5 log cycles reduction at day 45), while L. plantarum CRL691 was only slightly inhibited (0.5 log cycles) up to the second week of storage, then counts around 10(6)-10(7)CFU/g were reached. Changes in pH values from 6.3 to 5.8 were produced and gas formation was observed in active and control packages. The low inhibitory effectiveness against lactic acid bacteria is in correlation with the low activity observed for lactocin 705 in the presence of fat; Wieners fat content (20-30%) may adversely affect antimicrobial activity. This study supports the feasibility of using polymers activated with L. curvatus CRL705 bacteriocins to control Listeria on the surface of Wieners and highlights the importance of evaluating antimicrobial packaging systems for each particular food application.

  11. Pediocin SA-1: A selective bacteriocin for controlling Listeria monocytogenes in maize silages.

    Science.gov (United States)

    Amado, Isabel R; Fuciños, Clara; Fajardo, Paula; Pastrana, Lorenzo

    2016-10-01

    In this study, we assessed the potential as silage additive of a bacteriocin produced by Pediococcus acidilactici Northern Regional Research Laboratory (NRRL) B-5627 (pediocin SA-1). Maize was inoculated either with a bacterial starter alone (I) or in combination with the bacteriocin (IP), and untreated silage served as control. We monitored the products of fermentation (ethanol, and lactic and acetic acids), the microbial population, and the presence of the indicator strain Listeria monocytogenes Colección Española de Cultivos Tipo (CECT) 4032 (1×10(5) cfu/g) after 1, 2, 5, 8, 16, and 30d of ensiling. Our results indicated antilisterial activity of the bacteriocin, anticipating the disappearance of L. monocytogenes in IP compared with I and control silages. The PCR-denaturing gradient gel electrophoresis analysis revealed the addition of the bacteriocin did not affect the bacterial communities of the spontaneous fermentation, and the inoculant-containing bacteria (Lactobacillus plantarum, Lactobacillus buchneri, and Enterococcus faecium) were found in addition to the bacterial communities of untreated maize silages in I and IP silages. Both treatments increased the concentration of antimicrobial compounds (acetic acid, ethanol, and 1,2-propanodiol) and led to lower residual sugar contents compared with the control, which would provide enhanced aerobic stability. The fact that the identified species L. plantarum, L. buchneri, and E. faecium produce some of these inhibitory compounds, together with their persistence throughout the 30d of fermentation, suggest these bacteria could actively participate in the ensiling process. According to these results, pediocin SA-1 could be used as an additive to control the presence of L. monocytogenes in maize silages selectively, while improving their fermentative quality and eventually their aerobic stability.

  12. Bacteriocin production and resistance to drugs are advantageous features for Lactobacillus acidophilus La-14, a potential probiotic strain.

    Science.gov (United States)

    Todorov, Svetoslav Dimitrov; Furtado, Danielle Nader; Saad, Susana Marta Isay; Gombossy de Melo Franco, Bernadette Dora

    2011-10-01

    L. acidophilus La-14 produces bacteriocin active against L. monocytogenes ScottA (1600 AU/ml) in MRS broth at 30°C or 37°C. The bacteriocin proved inhibitory to different serological types of Listeria spp. Antimicrobial activity was completely lost after treatment of the cell-free supernatant with proteolytic enzymes. Addition of bacteriocin produced by L. acidophilus La-14 to a 3 h-old culture of L. monocytogenes ScottA repressed cell growth in the following 8h. Treatment of stationary phase cells of L. monocytogenes ScottA (107-108 CFU/ml) by the bacteriocin resulted in growth inhibition. Growth of L. acidophilus La-14 was not inhibited by commercial drugs from different generic groups, including nonsteroidal anti-inflammatory drugs (NSAID) containing diclofenac potassium or ibuprofen arginine. Only one non-antibiotic drug tested, Atlansil (an antiarrhythmic agent), had an inhibitory effect on L. acidophilus La-14 with MIC of 2.5 mg/ml. L. acidophilus La-14 was not affected by drugs containing sodium or potassium diclofenac. L. acidophilus La-14 shows a good resistance to several drugs and may be applied in combination for therapeutic use.

  13. ADMINISTRATIVE CIRCULARS

    CERN Multimedia

    Division des ressources humaines

    2000-01-01

    N° 2 (Rev. 1) - March 2000Guidelines and procedures concerning recruitment and probation period of staff membersN° 9 (Rev. 2) - March 2000Staff members contractsN° 16 (Rev. 2) - January 2000TrainingN° 30 (Rev. 1) - January 2000Indemnities and reimbursements upon taking up appointment and termination of contractN° 32 - February 2000Principles and procedures governing complaints of harassmentThese circular have been amended (No 2, N° 9, N° 16 and N° 30) or drawn up (N° 32).Copies are available in the Divisional Secretariats.Note:\tAdministrative and operational circulars, as well as the lists of those in force, are available for consultation in the server SRV4_Home in the Appletalk zone NOVELL (as GUEST or using your Novell username and password), volume PE Division Data Disk.The Word files are available in the folder COM, folder Public, folder ADM.CIRC.docHuman Resources DivisionTel. 74128

  14. Frequency of bacteriocin resistance development and associated fitness costs in Listeria monocytogenes.

    Science.gov (United States)

    Gravesen, A; Jydegaard Axelsen, A-M; Mendes da Silva, J; Hansen, T B; Knøchel, S

    2002-02-01

    Bacteriocin-producing starter cultures have been suggested as natural food preservatives; however, development of resistance in the target organism is a major concern. We investigated the development of resistance in Listeria monocytogenes to the two major bacteriocins pediocin PA-1 and nisin A, with a focus on the variations between strains and the influence of environmental conditions. While considerable strain-specific variations in the frequency of resistance development and associated fitness costs were observed, the influence of environmental stress seemed to be bacteriocin specific. Pediocin resistance frequencies were determined for 20 strains and were in most cases ca. 10(-6). However, two strains with intermediate pediocin sensitivity had 100-fold-higher pediocin resistance frequencies. Nisin resistance frequencies (14 strains) were in the range of 10(-7) to 10(-2). Strains with intermediate nisin sensitivity were among those with the highest frequencies. Environmental stress in the form of low temperature (10 degrees C), reduced pH (5.5), or the presence of NaCl (6.5%) did not influence the frequency of pediocin resistance development; in contrast, the nisin resistance frequency was considerably reduced (<5 x 10(-8)). Pediocin resistance in all spontaneous mutants was very stable, but the stability of nisin resistance varied. Pediocin-resistant mutants had fitness costs in the form of reduction down to 44% of the maximum specific growth rate of the wild-type strain. Nisin-resistant mutants had fewer and less-pronounced growth rate reductions. The fitness costs were not increased upon applying environmental stress (5 degrees C, 6.5% NaCl, or pH 5.5), indicating that the bacteriocin-resistant mutants were not more stress sensitive than the wild-type strains. In a saveloy-type meat model at 5 degrees C, however, the growth differences seemed to be negligible. The applicational perspectives of the results are discussed.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. Release of bacteriocins from nanofibers prepared with combinations of poly(d,l-lactide) (PDLLA) and poly(ethylene oxide) (PEO).

    Science.gov (United States)

    Heunis, Tiaan; Bshena, Osama; Klumperman, Bert; Dicks, Leon

    2011-01-01

    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.

  17. Bacteriocin protein BacL1 of Enterococcus faecalis is a peptidoglycan D-isoglutamyl-L-lysine endopeptidase.

    Science.gov (United States)

    Kurushima, Jun; Hayashi, Ikue; Sugai, Motoyuki; Tomita, Haruyoshi

    2013-12-27

    Enterococcus faecalis strains are commensal bacteria in humans and other animals, and they are also the causative agent of opportunistic infectious diseases. Bacteriocin 41 (Bac41) is produced by certain E. faecalis clinical isolates, and it is active against other E. faecalis strains. Our genetic analyses demonstrated that the extracellular products of the bacL1 and bacA genes, which are encoded in the Bac41 operon, coordinately express the bacteriocin activity against E. faecalis. In this study, we investigated the molecular functions of the BacL1 and BacA proteins. Immunoblotting and N-terminal amino acid sequence analysis revealed that BacL1 and BacA are secreted without any processing. The coincidental treatment with the recombinant BacL1 and BacA showed complete bacteriocin activity against E. faecalis, but neither BacL1 nor BacA protein alone showed the bacteriocin activity. Interestingly, BacL1 alone demonstrated substantial degrading activity against the cell wall fraction of E. faecalis in the absence of BacA. Furthermore, MALDI-TOF MS analysis revealed that BacL1 has a peptidoglycan D-isoglutamyl-L-lysine endopeptidase activity via a NlpC/P60 homology domain. These results collectively suggest that BacL1 serves as a peptidoglycan hydrolase and, when BacA is present, results in the lysis of viable E. faecalis cells.

  18. 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.

  19. 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.

  20. Comparison of two methods for purification of plantaricin ST31, a bacteriocin produced by Lactobacillus plantarum ST31 Comparação de dois métodos de purificação da plantaricina ST31, a bacteriocina produzida por Lactobacillus plantarum ST31

    Directory of Open Access Journals (Sweden)

    Svetoslav D. Todorov

    2004-06-01

    Full Text Available Two methods of purification of the plantaricin ST31, a bacteriocin produced by Lactobacillus plantarum ST31 are used in this study - the method of ammonium sulfate precipitation, Sep-pack C18 cartridge and reverse-phase HPLC chromatography on C18 Nucleosil column, and the method of direct purification by cation exchange SP Sepharose Fast Flow column Amersham (Pharmacia Biotech. The purity of the products from the two experimental protocols are examined for their molecular weight, aminoacid composition and sequence. Comparison of results show that the plantaricins purified with the two methods are identical. Both methods may be used to purify plantaricin ST31. Comparison of the yield in the purification protocols is 0.8% in the HPLC experimental protocol and 5.9% in the cation-exchange chromatography method.Dois métodos de purificação de plantaricin ST31, uma bacteriocina produzida por Lactobacillus plantarum ST31 foram usados neste estudo - o método de precipitação pelo sulfato de amônia usando cartucho Sep-pack C18 para a filtração e HPLC de fase reversa em coluna de C18 Nucleosil, e o método de purificação direta por troca catiônica SP Sepharose "Fast Flow column Amersham" (Pharmacia Biotech. A pureza dos produtos obtidos pelos dois protocolos foi examinada através da determinação dos pesos moleculares, composição e seqüência dos aminoácidos. A comparação destes resultados revelou que, em termos da pureza dos produtos, não havia diferenças entre os dois métodos de purificação podendo-se, portanto, utilizar qualquer um dos protocolos de purificação testados. No entanto, o rendimento da purificação pelo método da troca catiônica foi de 5.9% enquanto o do método HPLC foi de 0.8%.

  1. 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.

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

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-19

    Oct 19, 2009 ... vents (methanol, ethanol, butanol, isoamylol, chloroform, N-hexane and acetone) were used at the working concentration of 50% (v/v). The detergents Tween 20, ..... during batch fermentation. Appl. Microbiol. Biotechnol.

  3. Estimation of combined effects of carbon and nitrogen sources on the growth and bacteriocin production of Lactobacillus salivarius from human source.

    Science.gov (United States)

    Tomás, María Silvina Juárez; Bru, Elena; Nader-Macías, María Elena Fátima

    2010-04-01

    Vaginal Lactobacillus salivarius CRL 1328 (Centro de Referencia para Lactobacilos Culture Collection) or the bacteriocin that produces could be included in a urogenital probiotic formula to prevent urogenital infections in women. The objective of this work was to determine the effects of different carbon and nitrogen sources on the growth and bacteriocin production of this microorganism. A fractional factorial design 3(5-1) was applied to evaluate the effects of five nutrients (glucose, lactose, yeast extract, tryptone and meat peptone), at three different concentrations (0, 1 and 2%). Results were statistically analyzed for linear and quadratic effects of nutrients, along with their interactions. All the nutrients tested stimulated the cell growth and bacteriocin production, but lactose had not a significant influence on the last response. The linear effects of higher magnitude on biomass and bacteriocin production were those of yeast extract and tryptone. The results demonstrated that there were significant interactions between the different nutrients, depending on the response evaluated. Maximum bacteriocin production was reached in different growth media with a lower cost than conventional culture media used in the laboratory. These findings will contribute to the design of a pharmaceutical product for the restoration of ecological balance of urogenital tract.

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

    African Journals Online (AJOL)

    African Journal of Biotechnology ... Fermentation of various foods by lactic acid bacteria (LAB) is one of the oldest forms of ... scientific research about lactic acid bacteria as probiotics and their bacteriocins for healthy nutrition of fermented food.

  5. New developments and applications of bacteriocins and peptides in foods.

    Science.gov (United States)

    Mills, S; Stanton, C; Hill, C; Ross, R P

    2011-01-01

    There is an increased desire for sophisticated foods, whereby consumers harbor higher expectations of health-promoting benefits above basic nutrition. Moreover, there is a move from the adulteration of foods with chemical preservatives toward biopreservation. Such expectations have led scientists to identify novel approaches to satisfy both demands, which utilize bacteriocin and peptide-based solutions. The best known examples of biopreservation involve bacteriocins. However, with the exception of nisin, bacteriocins have received limited use in the food industry. Peptides can be added to foods to improve consumer health. Some of the best known examples are angiotensin I-converting enzyme (ACE)-inhibitory peptides, which inhibit ACE, a key enzyme involved in blood pressure (BP) regulation. To be effective, these peptides must be bioavailable, but by their nature, peptides are degraded by digestion with proteolytic enzymes. This review critically discusses the use and potential of peptides and bacteriocins in food systems in terms of safety, quality, and improvement of human health.

  6. Potentials for bacteriocin development to control Campylobacter in broilers

    Science.gov (United States)

    Dramatically enhanced biosecurity, enhanced fly screen control, competitive exclusion, immunization and phage therapies may hold suggestions to experimentally control flock infections but have yet to be demonstrated as commercially plausible or effective. Alternatively, bacteriocins (BCN) which are...

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

    African Journals Online (AJOL)

    SERVER

    2007-11-19

    Nov 19, 2007 ... bacteria isolated from West African soft cheese. Adetunji ... bacteriocin by agar well diffusion method using the supernatant of centrifuged test cultures. Four ... which are recalcitrant to traditional food preservation method ...

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

    African Journals Online (AJOL)

    Cultivation, isolation and characterization of bacteriocin from fresh cow milk and meat samples obtained from Lapai Market in Niger State Nigeria. ... effective against predominant food spoilers (Saccharomyces, Pseudomonas, Klebsiella and ...

  9. Circular causality.

    Science.gov (United States)

    Thomas, R

    2006-07-01

    The problem of disentangling complex dynamic systems is addressed, especially with a view to identifying those variables that take part in the essential qualitative behaviour of systems. The author presents a series of reflections about the methods of formalisation together with the principles that govern the global operation of systems. In particular, a section on circuits, nuclei, and circular causality and a rather detailed description of the analytic use of the generalised asynchronous logical description, together with a brief description of its synthetic use (OreverseO logic). Some basic rules are recalled, such as the fact that a positive circuit is a necessary condition of multistationarity. Also, the interest of considering as a model, rather than a well-defined set of differential equations, a variety of systems that differ from each other only by the values of constant terms is emphasised. All these systems have a common Jacobian matrix and for all of them phase space has exactly the same structure. It means that all can be partitioned in the same way as regards the signs of the eigenvalues and thus as regards the precise nature of any steady states that might be present. Which steady states are actually present, depends on the values of terms of order zero in the ordinary differential equations (ODEs), and it is easy to find for which values of these terms a given point in phase space is steady. Models can be synthesised first at the level of the circuits involved in the Jacobian matrix (that determines which types and numbers of steady states are consistent with the model), then only at the level of terms of order zero in the ODE's (that determines which of the steady states actually exist), hence the title 'Circular casuality'.

  10. Mechanisms of resistance to bacteriocins targeting the mannose phosphotransferase system.

    Science.gov (United States)

    Kjos, Morten; Nes, Ingolf F; Diep, Dzung B

    2011-05-01

    The membrane proteins IIC and IID of the mannose phosphotransferase system (Man-PTS) together form a membrane-located complex that serves as a receptor for several different bacteriocins, including the pediocin-like class IIa bacteriocins and the class IIc bacteriocin lactococcin A. Bacterial strains sensitive to class IIa bacteriocins readily give rise to resistant mutants upon bacteriocin exposure. In the present study, we have therefore investigated lactococcin A-resistant mutants of Lactococcus lactis as well as natural food isolates of Listeria monocytogenes with different susceptibilities to class IIa bacteriocins. We found two major mechanisms of resistance. The first involves downregulation of Man-PTS gene expression, which takes place both in spontaneous resistant mutants and in natural resistant isolates. The second involves normal expression of the Man-PTS system, but the underlying mechanism of resistance for these cells is unknown. In some cases, the resistant phenotype was linked to a shift in the metabolism; i.e., reduced growth on glucose due to reduction in Man-PTS expression was accompanied by enhanced growth on another sugar, such as galactose. The implications of these findings in terms of metabolic heterogeneity are discussed.

  11. 细菌素的分子生物学研究进展%Development of Biological and Molecular Characterization of Bacteriocins

    Institute of Scientific and Technical Information of China (English)

    崔德凤; 周波; 张永红

    2011-01-01

    Bacteriocins are a heterogeneous group of ribosomally synthesized antibacterial peptides or protein from some bacteria species. They are expected to become alternatives of food additives and antibiotics for their broad-spectrum antimicrobial activity, This paper reviews the bacteriocins molecular structure and function, genotyping, biosynthesis and their gene regulation, mode of antibacterial action and bacteria species of bacteriocin producing.%细菌素作为细菌合成的蛋白质(多肽)类抑菌物质,其广谱的抗菌活性,有望成为食品添加剂以及抗生素的替代品.主要对细菌素的分类及其作用机制、细菌素的生物合成及其调控,以及细菌素产生菌加以阐述.

  12. 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...

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

    Directory of Open Access Journals (Sweden)

    Nemanja Mirkovic

    2015-01-01

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

  14. Pediocin PA-1, a Bacteriocin from Pediococcus acidilactici PAC1.0, Forms Hydrophilic Pores in the Cytoplasmic Membrane of Target Cells

    NARCIS (Netherlands)

    Chikindas, Michael L.; García-Garcerá, Maria J.; Driessen, Arnold J.M.; Ledeboer, Aat M.; Nissen-Meyer, Jon; Nes, Ingolf F.; Abee, Tjakko; Konings, Wilhelmus; Venema, Gerhardus

    1993-01-01

    Pediocin PA-1 is a bacteriocin which is produced by Pediococcus acidilactici PAC1.0. We demonstrate that pediocin PA-1 kills sensitive Pediococcus cells and acts on the cytoplasmic membrane. In contrast to its lack of impact on immune cells, pediocin PA-1 dissipates the transmembrane electrical

  15. 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...

  16. 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). ...

  17. Pediocin PA-1, a Bacteriocin from Pediococcus acidilactici PAC1.0, Forms Hydrophilic Pores in the Cytoplasmic Membrane of Target Cells

    NARCIS (Netherlands)

    Chikindas, Michael L.; García-Garcerá, Maria J.; Driessen, Arnold J.M.; Ledeboer, Aat M.; Nissen-Meyer, Jon; Nes, Ingolf F.; Abee, Tjakko; Konings, Wilhelmus; Venema, Gerhardus

    1993-01-01

    Pediocin PA-1 is a bacteriocin which is produced by Pediococcus acidilactici PAC1.0. We demonstrate that pediocin PA-1 kills sensitive Pediococcus cells and acts on the cytoplasmic membrane. In contrast to its lack of impact on immune cells, pediocin PA-1 dissipates the transmembrane electrical pote

  18. Characterization of anti-listeria bacteriocins isolated from shellfish: Potential antimicrobials to control non-fermented seafood

    OpenAIRE

    Pinto, Ana Luísa; Fernandes, Melissa; Pinto, Cristina; Albano, Helena; Castilho, Fernanda; Teixeira, Paula; Gibbs, Paul A

    2009-01-01

    This work had as main objectives to characterize two bacteriocins produced by lactic acid bacteria (LAB) previously isolated from non-fermented seafood, in order to evaluate their potential as new food protective agents. The two bacteriocinogenic isolates were identified by Polymerase Chain Reaction (PCR) using genusand species-specific primers, and confirmed by 16S rDNA sequencing, as Enterococcus faecium and Pediococcus pentosaceus. The antimicrobial spectrum of each strain incl...

  19. Sakacin Q produced by Lactobacillus curvatus ACU-1: functionality characterization and antilisterial activity on cooked meat surface.

    Science.gov (United States)

    Rivas, Franco P; Castro, Marcela P; Vallejo, Marisol; Marguet, Emilio; Campos, Carmen A

    2014-08-01

    This work was conducted to evaluate the antilisterial activity of sakacin Q produced by Lactobacillus curvatus ACU-1 on the surface of cooked pork meat. A genetic re-characterization of the producer strain and a study of the structural genes involved in bacteriocin production were carried out as complementary data. Studies indicated that the bacteriocin was not attached to the producer cells favoring pre-purifications steps. Bacteriocin effectiveness was not compromised by adsorption to meat and fat tissues. Several ways of dispensing the bacteriocin onto the meat surface, namely cell culture, cell free supernatant (CFS), a mixture of both and freeze-dried reconstituted CFS, were investigated. The use of the latter was the most effective one to control Listeria growth within studied systems. L. curvatus ACU-1 and its bacteriocin presented promising technological characteristics that made them suitable for meat biopreservation.

  20. Analysis of natural isolates of Lactobacilli resistant to bacteriocin nisin

    Directory of Open Access Journals (Sweden)

    Strahinić Ivana D.

    2005-01-01

    Full Text Available The collection of lactic acid bacteria (LAB was made by isolation of microorganisms from fermented products traditionally manufactured in different geographical regions (high mountains, river valleys, seaside, etc. Among collected LAB, 51 isolates were identified as Lactobacillus sp. Results showed that all isolated lactobacilli were mesophilic strains, since they grew at 15°C and 30°C but not at 45°C. Testing the ability of isolated lactobacilli to grow in the presence of nisin revealed that Lactobacillus sp. isolates designed BGCGK4, BGHN40, BGBUK2-8, BGBUK2-7 and BGBUK2-16 were resistant to nisin. Determination of the minimal inhibitory concentrations (MIC for nisin revealed that the most resistant isolate was Lactobacillus sp. BGCGK4. Isolate BGBUK2-16, determined as Lactobacillus paracasei subsp. paracasei, produces bacteriocin, named Bac217 and showed a resistance to 8000 IU/ml of nisin. Plasmid curing of BGBUK2-16 resulted in derivatives BGBUK2-16/K2 and BGBUK2-16/K4. Derivative BGBUK2-16/K2 retained resistance to Bac217 and nisin, but lost the ability to synthesise Bac217. Derivative BGBUK2-16/K4 lost concomitantly the resistance to both Bac217 and nisin.

  1. Colicin import into E. coli cells: a model system for insights into the import mechanisms of bacteriocins.

    Science.gov (United States)

    Kim, Young Chan; Tarr, Alexander W; Penfold, Christopher N

    2014-08-01

    Bacteriocins are a diverse group of ribosomally synthesized protein antibiotics produced by most bacteria. They range from small lanthipeptides produced by lactic acid bacteria to much larger multi domain proteins of Gram negative bacteria such as the colicins from Escherichia coli. For activity bacteriocins must be released from the producing cell and then bind to the surface of a sensitive cell to instigate the import process leading to cell death. For over 50years, colicins have provided a working platform for elucidating the structure/function studies of bacteriocin import and modes of action. An understanding of the processes that contribute to the delivery of a colicin molecule across two lipid membranes of the cell envelope has advanced our knowledge of protein-protein interactions (PPI), protein-lipid interactions and the role of order-disorder transitions of protein domains pertinent to protein transport. In this review, we provide an overview of the arrangement of genes that controls the synthesis and release of the mature protein. We examine the uptake processes of colicins from initial binding and sequestration of binding partners to crossing of the outer membrane, and then discuss the translocation of colicins through the cell periplasm and across the inner membrane to their cytotoxic site of action. This article is part of a Special Issue entitled: Protein trafficking and secretion in bacteria. Guest Editors: Anastassios Economou and Ross Dalbey.

  2. Escherichia coli bacteriocins: antimicrobial efficacy and prevalence among isolates from patients with bacteraemia.

    Science.gov (United States)

    Budič, Maruška; Rijavec, Matija; Petkovšek, Ziva; Zgur-Bertok, Darja

    2011-01-01

    Bacteriocins are antimicrobial peptides generally active against bacteria closely related to the producer. Escherichia coli produces two types of bacteriocins, colicins and microcins. The in vitro efficacy of isolated colicins E1, E6, E7, K and M, was assessed against Escherichia coli strains from patients with bacteraemia of urinary tract origin. Colicin E7 was most effective, as only 13% of the tested strains were resistant. On the other hand, 32%, 33%, 43% and 53% of the tested strains exhibited resistance to colicins E6, K, M and E1. Moreover, the inhibitory activity of individual colicins E1, E6, E7, K and M and combinations of colicins K, M, E7 and E1, E6, E7, K, M were followed in liquid broth for 24 hours. Resistance against individual colicins developed after 9 hours of treatment. On the contrary, resistance development against the combined action of 5 colicins was not observed. One hundred and five E. coli strains from patients with bacteraemia were screened by PCR for the presence of 5 colicins and 7 microcins. Sixty-six percent of the strains encoded at least one bacteriocin, 43% one or more colicins, and 54% one or more microcins. Microcins were found to co-occur with toxins, siderophores, adhesins and with the Toll/Interleukin-1 receptor domain-containing protein involved in suppression of innate immunity, and were significantly more prevalent among strains from non-immunocompromised patients. In addition, microcins were highly prevalent among non-multidrug-resistant strains compared to multidrug-resistant strains. Our results indicate that microcins contribute to virulence of E. coli instigating bacteraemia of urinary tract origin.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  5. Synthesis of bacteriocins in liquid cultures of Streptococcus mutans.

    Science.gov (United States)

    Kelstrup, J; Funder-Nielsen, T D

    1977-06-01

    Strains of Streptococcus mutans synthesized bacteriocins in agar plates, but synthesis of detectable bacteriocins in liquid media took place only under certain culture conditions. The composition of the medium proved to be crucial. Trypticase Soy Broth with 4% Yeast Extract meeting the requirements. The effect of the Yeast Extract is obscure, for some strains also formed detectable bacteriocins in a special Trypticase medium without this agent. It was noted that the broth should be filter-sterilized rather than autoclaved and only a few days old. Attempts at liberating cell-bound bacteriocins from washed cells were unsuccessful, even when they were treated with ultrasound, EDTA, or various chemicals followed by ultrasound. On the basis of size and sensitivity to heat the bacteriocins could be divided into two groups, while their resistance to ether and chloroform and to trypsin did not follow this pattern. Dependence on plasmids could not be demonstrated by attempts at curing with acridine orange or ethidium bromide; and the involvement of phages was unlikely, since the inhibition was not transmissible and phage-like structures were not observed in the electron microscope.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. Purification of the Bacteriocin Isolated from Lactobacillus acidophilus and Effect of Surfactant on the Antibacterial Activity of Bacteriocin%嗜酸乳杆菌细菌素的分离纯化及表面活性剂对其活性的影响1)

    Institute of Scientific and Technical Information of China (English)

    张帅; 王金凤; 马永强

    2012-01-01

      从本研究室保藏的一株来自于凯菲尔粒的嗜酸乳杆菌培养基质中分离出具有抑菌活性的蛋白组分———细菌素,对该嗜酸乳杆菌所产生的细菌素的分离方法及表面活性剂对其抑菌活性的影响作用进行了研究。结果表明,嗜酸乳杆菌在添加了油酸的 MRS 培养基中培养16h 后达到产细菌素高峰;对细菌素分离纯化研究包括三个步骤:硫酸铵沉淀、离子交换色谱(IEC)和疏水作用色谱(HIC)。不同类型的表面活性剂对细菌素的抑菌活性具有不同的影响。%  Bacteriocin which is a kind of protein with antibacterial activity is produced from L actobacillus acidophilus ,and the strain is isolated from kefir grain preserved in the lab .The separation method about bacteriocin and the influence of the different surfactants on the antibacterial activity of bacteriocin is stud -ied .The results show that L actobacillus acidophilus is cultured in MRS medium addind oleic acid after 16h culture ,a peak of the bacteriocin-producing is reached .And The purification method about bacterio-cin includes three operations ,which separately are ammonium sulfate precipitation ,ion exchange chroma-tography(IEC)and Hydrophobic Interaction Chromatography . The different kinds of surfactants may have the different effects on the antibacterial activity of bacteriocin .

  8. Sonorensin: an antimicrobial peptide, belonging to the heterocycloanthracin subfamily of bacteriocins, from a new marine isolate, Bacillus sonorensis MT93.

    Science.gov (United States)

    Chopra, Lipsy; Singh, Gurdeep; Choudhary, Vikas; Sahoo, Debendra K

    2014-05-01

    Marine environments are the greatest fronts of biodiversity, representing a resource of unexploited or unknown microorganisms and new substances having potential applications. Among microbial products, antimicrobial peptides (AMPs) have received great attention recently due to their applications as food preservatives and therapeutic agents. A new marine soil isolate producing an AMP was identified as Bacillus sonorensis based on 16S rRNA gene sequence analysis. It produced an AMP that showed a broad spectrum of activity against both Gram-positive and Gram-negative bacteria. The peptide, named sonorensin, was purified to homogeneity using a combination of chromatographic techniques. The intact molecular mass of the purified peptide, 6,274 Da, as revealed by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF), was in agreement with Tricine-SDS-PAGE analysis. A PCR array of primers was used to identify AMP structural genes, which allowed the successful amplification of the related genes from strain MT93. The putative open reading frame of sonorensin was amplified, cloned into the pET-32a(+) vector, expressed as a thioredoxin (Trx) fusion protein in Escherichia coli, and then purified. Sequence alignment analysis revealed that the bacteriocin being reported could belong to new subfamily of bacteriocins, heterocycloanthracin. The peptide indicated its potential as a biocontrol agent or food antimicrobial agent, due to its antimicrobial activity against bacteria such as Listeria monocytogenes and Staphylococcus aureus. This is the first report of the production, purification, and characterization of wild-type and recombinant bacteriocin by B. sonorensis and the first bacteriocin of the heterocycloanthracin subfamily to be characterized.

  9. In Vitro Evaluation of Bacteriocins Activity Against Listeria monocytogenes Biofilm Formation.

    Science.gov (United States)

    Camargo, Anderson Carlos; de Paula, Otávio Almeida Lino; Todorov, Svetoslav Dimitrov; Nero, Luís Augusto

    2016-03-01

    The present study aimed to assess the activity of cell-free supernatant (CFS) containing bacteriocins on the formation and maintenance of biofilms developed by Listeria monocytogenes, and the associated effect of bacteriocins and ethylene-diamine-tetra-acetic acid (EDTA) on the formed biofilm. CFS from 9 lactic acid bacteria (LAB) strains was tested for inhibitory activity against 85 L. monocytogenes isolates and 21 LAB strains. Then, 12 L. monocytogenes strains were selected based on genetic profiles and sensitivity to CFS and were subjected to an in vitro assay to assess biofilm formation in microtiter plates, considering different culture media and incubation conditions. Based on these results, 6 L. monocytogenes strains were subjected to the same in vitro procedure to assess biofilm formation, being co-inoculated with CFS. In addition, these strains were subjected to the same in vitro procedure, modified by adding the CFS after biofilm formation. Relevant decrease in biofilm formation was observed in the first experiment, but CFS added after biofilm formation did not eliminate them. CFS from Lactobacillus curvatus ET31 were selected due to its anti-biofilm activity, being associated to EDTA at different concentrations and tested for biofilm control of three strains of L. monocytogenes, using the same in vitro procedure described previously. Concentrated bacteriocin presented poor performance in eliminating formed biofilms, and EDTA concentration presented no evident interference on biofilm elimination. Twelve selected L. monocytogenes strains were positive for investigated virulence makers and negative for luxS gene, recognized as being involved in biofilm formation. Selected L. monocytogenes strains were able to produce biofilms under different conditions. CFSs have the potential to prevent biofilm formation, but they were not able to destroy already formed biofilms. Nevertheless, low concentrations of CFS combined with EDTA caused a relevant reduction in

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  12. A new approach to determine the stereospecificity in lipase catalysed hydrolysis using circular dichroism (CD): lipases produce optically active diglycerides from achiral triglycerides.

    Science.gov (United States)

    Uzawa, H; Nishida, Y; Ohrui, H; Meguro, H

    1990-04-30

    We describe a sensitive CD method for determining the stereospecificity in lipase (E.C.3.1.1.3) catalysed hydrolysis of triacyl glycerols into diacyl glycerols. The diglycerols were converted to chiral tert-butyldimethylsilylated 1,2- or 2,3-di-O-benzoyl-sn-glycerol (5 or 5'), and their CD was measured. This approach showed for the first time that lipases produce optically active diacyl glycerides from achiral tripalmitin and tribenzoyl glyceride with a variable extent of enantioselectivity depending on the acyl groups and the enzymes.

  13. Characterization of a noncytotoxic bacteriocin from probiotic Lactobacillus plantarum DM5 with potential as a food preservative.

    Science.gov (United States)

    Das, Deeplina; Goyal, Arun

    2014-10-01

    The aim of this work was to purify and characterize the bacteriocin produced by probiotic Lactobacillus plantarum DM5 in order to evaluate its potential as nutraceuticals. Lb. plantarum DM5 exhibited in vitro probiotic properties such as high resistance to gastric juice and bile salt, adherence to human adenocarcinoma (HT-29) cells, bile salt hydrolase and cholesterol assimilation activity. Moreover, Lb. plantarum DM5 showed bacteriocin activity against several major food borne pathogens. Zymogram analysis of purified bacteriocin (plantaricin DM5) showed a molecular size of ∼15.2 kDa. Plantaricin DM5 was sensitive to proteolytic enzymes but stable in the pH range of 2.0-10.0, and it was heat resistant (121 °C for 15 min) and remained active upon treatment with surfactants and detergents. Cytotoxicity analysis of plantaricin DM5 on human embryonic kidney 293 (HEK 293) and human cervical cancer (HeLa) cell lines revealed its nontoxic and biocompatible nature. To the best of our knowledge, this is the first study on the isolated strain expressing probiotic properties and broad antimicrobial activity without any cytotoxic effect on mammalian cells from indigenous fermented beverage Marcha from India, and thus contributes to the food industry as a novel bio-preservant.

  14. Bacteriocins in S. mutans strains isolated from children with and without dental caries: biotypes and sensitivity to antibiotics.

    Science.gov (United States)

    Gamboa, Fredy; Chaves, Margarita; Estupiñan, Mabel; Galindo, Adriana

    2008-01-01

    The aim of this study was to determine the production of bacteriocins in the Streptococcus mutans strains isolated from children with and without dental caries. With this purpose the dmft index was determined and non-stimulated saliva was collected from 53 3- to 5-year-old children. The samples were cultured on Mitis Salivarius Bacitracin agar and incubated anaerobically for two days at 37 degrees C. The isolates were biotyped using the Api-ZYM enzymatic system (bioMérieux; Marcy-lE'toile, France). Bacteriocin was detected using the double layer onto brain heart infusion agar technique and the minimal inhibitory concentrations of the isolates were evaluated against penicillin, amoxycillin, cefazolin, erythromycin, clindamycin, imipenem and vancomycin using an agar dilution method. The dental caries experience in these children was 66% (35/53) and dmft index average was 3.2 (range 2-6). S. mutans was found in the saliva of 33 children (62%). In the 33 strains of S. mutans, 10 biotypes were found. Eight (24%) of the 33 strains evaluated produced bacteriocins, 6 of these strains came from patients with dental caries and the other two from patients without dental caries. All isolates were highly sensitive to the antibiotics tested.

  15. Implementing circularity using partial evaluation

    DEFF Research Database (Denmark)

    Lawall, Julia Laetitia

    2001-01-01

    of an imperative C-like language, by extending the language with a new construct, persistent variables. We show that an extension of partial evaluation can eliminate persistent variables, producing a staged C program. This approach has been implemented in the Tempo specializer for C programs, and has proven useful......Complex data dependencies can often be expressed concisely by defining a variable in terms of part of its own value. Such a circular reference can be naturally expressed in a lazy functional language or in an attribute grammar. In this paper, we consider circular references in the context...

  16. Antimicrobial Activity Studies of Bactoriocin Produced by Lactobacilli Isolates from Carrot Kanji

    Directory of Open Access Journals (Sweden)

    Harshada M. Sowani

    2012-01-01

    Full Text Available Problem statement: In the present study, Staphylococcus aureus a causative agent of food poisoning is selected as a test organism to study the antimicrobial effect of bacteriocin. S. aureus produces number of exotoxins and enterotoxins which enters the body via contaminated food causing illness. Approach: In this case the use of antibiotics is one of the ways of treatment, but in addition to this if we advise such patients to consume the carrot kanji then it will cause better effect because carrot kanji is the naturally fermented food beverage consisting of microflora mainly the Lactobacilli. Results: The Lactobacilli have ability to produce antimicrobial compounds called bacteriocin. Isolation of bacteriocin was carried out from the naturally fermented carrot kanji. The bacteriocin produced by Lactobacilli was dialysed and used for the further studies. The well diffusion method is used to study the antimicrobial activity, effect of temperature, pH, enzymes on bacteriocin. From the diameter of zone of inhibition the activity of bacteriocin was determined. The sensitivity of bacteriocin at different pH range showed that at neutral pH the diameter of inhibition zone was greater than that at alkaline as well as acidic pH. Upto 100°C the bacteriocin activity was 80% but as temperature range increased upto 121°C it reduced sharply to 28%. Conclusion/Recommendations: In addition to this the effect of alpha amylase, trypsin, catalase enzyme on bacteriocin activity was also studied which shows positive results with alpha amylase, reduced activity with trypsin and catalase remained unaffected.

  17. Production of bacteriocin by Virgibacillus salexigens isolated from "terasi": a traditionally fermented shrimp paste in Indonesia.

    Science.gov (United States)

    Kobayashi, Takeshi; Agustini, Tri Winarni; Ibrahim, Ratna; Kamei, Kaeko; Kondo, Akihiro; Kajiwara, Michika; Ooka, Yoshihiro; Nakamura, Hidetoshi; Terahara, Takeshi; Imada, Chiaki

    2016-03-01

    A natural antibacterial-substance-producing gram-positive bacterium was isolated from terasi shrimp paste, a popular fermented product in Indonesia. This strain, a spore-forming and strictly aerobic bacterium, was identified as Virgibacillus salexigens by 16S rRNA gene sequence analysis. The antibacterial substance purified from the precipitated product in the culture supernatant of the strain using ammonium sulfate showed a broad inhibition spectrum against gram-positive bacteria, including a typical foodborne bacterium, namely, Listeria monocytogenes. The antibacterial activity of the substance was inactivated by treatments with various proteolytic enzymes. It was stable after heating or pH treatment, and approximately 60% of the initial activity remained even after heating at 121 °C for 15 min. In addition, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis indicated that its monoisotopic mass weight was 5318.4 Da (M+H)(+). On the basis of the results obtained by the automated Edman degradation technique and MALDI-TOF MS analysis, the substance can be classified as a member of Class IId bacteriocins, but it could not be identified as any of the previously purified substances except for the putative bacteriocin predicted from the draft genome sequence data of gram-positive bacteria such as Virgibacillus and Bacillus strains.

  18. Antagonistic Potential of Lactobacillus Spp against Enteropathogenic Bacteria; Purification and Characterization of their Bacteriocins

    Directory of Open Access Journals (Sweden)

    Asha

    2012-10-01

    Full Text Available In the present study, Lactobacillus (160 isolates were isolated from curd sample. The isolates were aimed to analyze the antibacterial potential against Escherichia coli, Vibrio cholerae sub sp., ogawa, V. cholerae sub sp., inaba, Klebsiella sp., Proteus sp. and Shigella dysenteriae. All the isolates were inhibiting the tested Enteropathogenic bacteria except S. dysenteriae. Lactobacillus isolates produced highest inhibition zone (30 to 37 mm against V. cholerae sub sp., inaba and Klebsiella sp., of the 160 isolates only ten Lactobacillus isolates (L1- L10 were used for the production of bacteriocins, purified by ammonium sulphate precipitation and ion exchange (DEAE cellulose chromatography. Maximum bacteriocin activity has been observed with Lf3 against V. cholerae ssp Inaba at 30°C, pH 6.0, 1.5 to 2.0% Na Cl/18 h in addition to L8, L9 and L10 (MW 100 to 106 KDa and Lf3 was found to be the most prominent potential isolate.

  19. Production of bacteriocin-like inhibitory substance by Bifidobacterium lactis in skim milk supplemented with additives.

    Science.gov (United States)

    Martinez, Fabio Andres Castillo; Domínguez, José Manuel; Converti, Attilio; Oliveira, Ricardo Pinheiro de Souza

    2015-08-01

    Bacteriocins are natural compounds used as food biopreservatives instead of chemical preservatives. Bifidobacterium animalis subsp. lactis (Bifid. lactis) was shown to produce a bacteriocin-like inhibitory substance (BLIS) able to inhibit the growth of Listeria monocytogenes selected as an indicator microorganism. To enhance this production by the strain Bifid. lactis BL 04, skim milk (SM) was used as a fermentation medium either in the presence or in the absence of yeast extract, Tween 80 or inulin as stimulating additives, and the results in terms of bacterial growth and BLIS production were compared with those obtained in a traditional high cost complex medium such as Man, Rogosa and Sharpe (MRS). To this purpose, all the cultivations were carried out in flasks at 200 rpm under anaerobic conditions ensured by a nitrogen flowrate of 1.0 L/min for 48 h, and BLIS production was quantified by means of a modified agar diffusion assay at low values of both temperature and concentration of List. monocytogenes. Although all these ingredients were shown to exert positive influence on BLIS production in both media, yeast extract and SM were by far the best ingredient and the best medium, respectively, allowing for a BLIS production at the late exponential phase of 2000 AU/ml.

  20. Persistence of the Oral Probiotic Streptococcus salivarius M18 Is Dose Dependent and Megaplasmid Transfer Can Augment Their Bacteriocin Production and Adhesion Characteristics

    OpenAIRE

    Burton, Jeremy P.; Wescombe, Philip A.; Macklaim, Jean M.; Chai, Melissa H. C.; Kyle Macdonald; Hale, John D. F.; John Tagg; Gregor Reid; Gloor, Gregory B.; Cadieux, Peter A.

    2013-01-01

    Bacteriocin-producing probiotic Streptococcus salivarius M18 offers beneficial modulatory capabilities within the oral microbiome, apparently through potent inhibitory activity against potentially deleterious bacteria, such as Streptococcus pyogenes. The oral cavity persistence of S. salivarius M18 was investigated in 75 subjects receiving four different doses for 28 days. Sixty per cent of the subjects already had some inhibitor-producing S. salivarius in their saliva prior to probiotic inte...

  1. Production of antilisterial bacteriocins by staphylococci isolated from bovine milk

    Science.gov (United States)

    A collection of 111 staphylococcal isolates recovered from healthy cows in 41 dairy herds in Brazil was surveyed for the production of bacteriocins. The group included 94 coagulase positive and 17 coagulase negative strains of staphylococci. All cultures were grown in tryptic soy broth for 18 h at ...

  2. Antimycobacterial activity of bacteriocins and their complexes with liposomes

    Science.gov (United States)

    Bacteriocins (Bcn) are natural peptides that are secreted by taxonomically distinct bacteria which exert bactericidal activity against other bacterial species. Their capacity to inhibit growth of virulent Mycobacterium tuberculosis H37Rv was evaluated in this study. Five Bcn were purified from sel...

  3. Development and stability of bacteriocin resistance 1 in Campylobacter spp

    Science.gov (United States)

    Aims: Several bacteriocins (BCNs) identified from chicken commensal bacteria dramatically reduced Campylobacter colonization in poultry and aredirected toward on farm control of this important food-borne human pathogen. BCN resistance in C. jejuni is very difficult to develop in vitro. In this study...

  4. Structure and uptake mechanism of bacteriocins targeting peptidoglycan renewal.

    Science.gov (United States)

    Zeth, Kornelius

    2012-12-01

    Bacteriocins are narrow-spectrum protein antibiotics released to kill related bacteria of the same niche. Uptake of bacteriocins depends critically on the presence of an uptake receptor in the outer membrane, a translocation pore and an energy-dependent activating system of the inner membrane. Most bacteriocins act on the inner membrane as pore-forming toxins or they target cytoplasmic DNA/RNA and ribosomal synthesis respectively. Only two bacteriocins are known to become activated in the periplasmic space and to inhibit the renewal process of the peptidoglycan structure. In Escherichia coli, the Cma (colicin M) phosphatase is activated in the periplasmic space by the FkpA chaperone and subsequently degrades the C55-PP precursor unit of the peptidoglycan. Pst (pesticin) from Yersinia pestis carries a lysozyme homology domain to degrade peptidoglycan. Import of Pst is only achieved if the N-terminal translocation domain can span the outer membrane and if extensive unfolding of the protein during membrane passage is permitted. There is considerable plasticity in the import pathway since a chimaera comprising the activity domain replaced by T4 lysozyme is also translocated and active in killing those bacteria carrying the FyuA receptor.

  5. 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.

  6. 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

    1991-01-01

    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, t

  7. BAGEL2 : mining for bacteriocins in genomic data

    NARCIS (Netherlands)

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

    2010-01-01

    Mining bacterial genomes for bacteriocins is a challenging task due to the substantial structure and sequence diversity, and generally small sizes, of these antimicrobial peptides. Major progress in the research of antimicrobial peptides and the ever-increasing quantities of genomic data, varying fr

  8. PURIFICATION AND CHARACTERIZATION OF NISIN PRODUCED BY LACTOCOCCUS LACTIS ISOLATED FROM INDIAN CURD

    Directory of Open Access Journals (Sweden)

    Saba A. Mahdy

    2015-12-01

    Full Text Available Lactococcus lactis isolated from traditional dairy Indian curd. Strains were preliminarily identified by PCR analysis and partial 16S rRNA confirmed that N5 were 100% identical to Lactococcus. lactis sp. lactis. The results revealed that only the bacteriocin produced from strain N5 was shown as being active against mostly gram positive bacteria The bacteriocin produced purified by precipitation followed by loading with gel chromatography. The partially purified bacteriocin was found to be stable over a wide range of pH, temperature and enzymes. The molecular weight of the peptide was judged to be 3.5 kDa by SDSpolyacrylamide gel electrophoresis.and conform to the result of mass spectrometry by maldi-tof test which calculated the mass of 3354.07 Da for nisin.These results indicate that bacteriocin produced by L. lactis sp. lactis N5 is a nisin.

  9. Circular polarisation in AGN

    NARCIS (Netherlands)

    Macquart, JP

    2002-01-01

    We discuss the constraints that recent observations place on circular polarisation in AGN. In many sources the circular polarisation is variable on short timescales, indicating that it originates in compact regions of the sources. The best prospects for gleaning further information about circular po

  10. Use of the Yeast Pichia pastoris as an Expression Host for Secretion of Enterocin L50, a Leaderless Two-Peptide (L50A and L50B) Bacteriocin from Enterococcus faecium L50▿

    Science.gov (United States)

    Basanta, Antonio; Gómez-Sala, Beatriz; Sánchez, Jorge; Diep, Dzung B.; Herranz, Carmen; Hernández, Pablo E.; Cintas, Luis M.

    2010-01-01

    In this work, we report the expression and secretion of the leaderless two-peptide (EntL50A and EntL50B) bacteriocin enterocin L50 from Enterococcus faecium L50 by the methylotrophic yeast Pichia pastoris X-33. The bacteriocin structural genes entL50A and entL50B were fused to the Saccharomyces cerevisiae gene region encoding the mating pheromone α-factor 1 secretion signal (MFα1s) and cloned, separately and together (entL50AB), into the P. pastoris expression and secretion vector pPICZαA, which contains the methanol-inducible alcohol oxidase promoter (PAOX1) to express the fusion genes. After transfer into the yeast, the recombinant plasmids were integrated into the genome, resulting in three bacteriocinogenic yeast strains able to produce and secrete the individual bacteriocin peptides EntL50A and EntL50B separately and together. The secretion was efficiently directed by MFα1s through the Sec system, and the precursor peptides were found to be correctly processed to form mature and active bacteriocin peptides. The present work describes for the first time the heterologous expression and secretion of a two-peptide non-pediocin-like bacteriocin by a yeast. PMID:20348300

  11. 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

  12. 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 industry

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

    African Journals Online (AJOL)

    TWAS Genomics Research Unit, Department of Medical Laboratory Sciences, School of ... peptide has shown to possess potential applications in the conferment of health benefits on the ... thermodynamic stability and structural integrity of the.

  14. 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 industry

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

    OpenAIRE

    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 industry, as such products can only contain a minimum of additives and at the same time need to have a shelf life that provides optimal consumer safety. One approach to accomplish this could be the additio...

  16. Bacteriocin production by strain Lactobacillus delbrueckii ssp. bulgaricus BB18 during continuous prefermentation of yogurt starter culture and subsequent batch coagulation of milk.

    Science.gov (United States)

    Simova, E D; Beshkova, D M; Angelov, M P; Dimitrov, Zh P

    2008-06-01

    By screening for bacteriocin-producing lactic acid bacteria of 1,428 strains isolated from authentic Bulgarian dairy products, Lb. bulgaricus BB18 strain obtained from kefir grain was selected. Out of 11 yogurt starters containing Lb. bulgaricus BB18 and S. thermophilus strains resistant to bacteriocin secreted by Lb. bulgaricus BB18 a yogurt culture (S. thermophilus 11A+Lb. bulgaricus BB18) with high growth and bacteriocinogenic activity in milk was selected. Continuous (pH-stat 5.7) prefermentation processes were carried out in milk at 37 degrees C in a 2l MBR bioreactor (MBR AG, Zurich, Switzerland) with an IMCS controller for agitation speed, temperature, dissolved oxygen, CO2 and pH. Prefermented milk with pH 5.7 coagulated in a thermostat at 37 degrees C until pH 4.8-4.9. S. thermophilus 11A and Lb. bulgaricus BB18 grew independently in a continuous mode at similar and sufficiently high-dilution rates (D=1.83 h(-1)-S. thermophilus 11A; D=1.80 h(-1)-Lb. bulgaricus BB18). The yogurt cultures developed in a stream at a high-dilution rate (D=2.03-2.28 h(-1)). The progress of both processes (growth and bacteriocin production) depended on the initial ratio between the two microorganisms. The continuous prefermentation process promoted conditions for efficient fermentation and bacteriocinogenesis of the starter culture during the batch process: strong reduction of the times for bacteriocin production and coagulation of milk (to 4.5-5.0 h); high cell productivity (lactobacilli-4x10(12) CFU ml(-1), streptococci-6x10(12) CFU ml(-1)); high productivity of bacteriocins (4,500 BU ml(-1))-1.7 times higher than the bacteriocinogenic activity of the batch starter culture.

  17. Bacteriocin-like substance from Bacillus amyloliquefaciens shows remarkable inhibition of Acanthamoeba polyphaga.

    Science.gov (United States)

    Benitez, Lisianne Brittes; Caumo, Karin; Brandelli, Adriano; Rott, Marilise Brittes

    2011-03-01

    The effectiveness of a bacteriocin-like substance (BLS) produced by Bacillus amyloliquefaciens was tested against Acanthamoeba polyphaga strains, and its cytotoxic potential on Vero cells was investigated. Amebicidal activity of the purified BLS was tested by plate bioassays with concentrations ranging from 12.5 to 6,400 AU mL(-1). Damage to A. pholyphaga cells was monitored using an inverted microscope and counted in a Fuchs-Rosenthal chamber after 24, 48, and 72 h. According to the results obtained, the BLS showed remarkable amebicidal and amebostatic effect on A. polyphaga and showed no cytotoxicity on the Vero cells. These results may have great relevance in the development of new acanthamoebicidal compounds.

  18. Publication of administrative circular

    CERN Multimedia

    HR Department

    2009-01-01

    ADMINISTRATIVE CIRCULAR NO. 23 (REV. 2) – SPECIAL WORKING HOURS Administrative Circular No. 23 (Rev. 2) entitled "Special working hours", approved following discussion in the Standing Concertation Committee on 9 December 2008, will be available on the intranet site of the Human Resources Department as from 19 December 2008: http://cern.ch/hr-docs/admincirc/admincirc.asp It cancels and replaces Administrative Circular No. 23 (Rev. 1) entitled "Stand-by duty" of April 1988. A "Frequently Asked Questions" information document on special working hours will also be available on this site. Paper copies of this circular will shortly be available in Departmental Secretariats. Human Resources Department Tel. 78003

  19. PUBLICATION OF ADMINISTRATIVE CIRCULAR

    CERN Multimedia

    HR Department

    2008-01-01

    ADMINISTRATIVE CIRCULAR NO. 23 (REV. 2) – SPECIAL WORKING HOURS Administrative Circular No. 23 (Rev. 2) entitled "Special working hours", approved following discussion in the Standing Concertation Committee meeting of 9 December 2008, will be available on the intranet site of the Human Resources Department as from 19 December 2008: http://cern.ch/hr-docs/admincirc/admincirc.asp It cancels and replaces Administrative Circular No. 23 (Rev. 1) entitled "Stand-by duty" of April 1988. A "Frequently Asked Questions" information document on special working hours will also be available on this site. Paper copies of this circular will shortly be available in departmental secretariats. Human Resources Department Tel. 78003

  20. Strong Trinucleotide Circular Codes

    Directory of Open Access Journals (Sweden)

    Christian J. Michel

    2011-01-01

    Full Text Available Recently, we identified a hierarchy relation between trinucleotide comma-free codes and trinucleotide circular codes (see our previous works. Here, we extend our hierarchy with two new classes of codes, called DLD and LDL codes, which are stronger than the comma-free codes. We also prove that no circular code with 20 trinucleotides is a DLD code and that a circular code with 20 trinucleotides is comma-free if and only if it is a LDL code. Finally, we point out the possible role of the symmetric group ∑4 in the mathematical study of trinucleotide circular codes.

  1. 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-p...... culture for cold-stored, cooked, sliced, and vacuum-packed meat products.......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...... activity corresponding to molecular sizes of 4.6 and 5.3 kDa. N-terminal amino acid sequencing showed that Leuc. carnosum 4010 produced two bacteriocins highly similar or identical to leucocin A and leucocin C. Application experiments showed that the addition of 10(7) cfu/g Leuc. carnosum 4010 to a vacuum...

  2. Regulation of Bacteriocin Synthesis by Quorum Sensing in Lactic Acid Bacteria:A Review%群体感应系统在乳酸菌产细菌素中的作用

    Institute of Scientific and Technical Information of China (English)

    满丽莉; 孟祥晨; 王辉; 赵日红

    2011-01-01

    Several lactic acid bacteria(LAB) produce peptides with antimicrobial activity usually referred to as bacteriocins.Bacteriocins are diverse in terms of structure,mode of action,antimicrobial spectrum,and potency.Both LAB and their bacteriocins are generally regarded as safe.Bacteriocins produced by LABs have demonstrated great potential as natural preservatives Intercellular communication has emerged as the key regulatory mechanism that controls the synthesis of bacteriocins via a regulatory strategy denominated quorum sensing,which allows population-wide synchronised production of antimicrobial peptides as a function of cell density.The intercellular communication phenomenon required for sensing of the cell density is mediated by secreted signaling molecules that accumulate in the environment as the cell density increase and activate signal transduction cascades,resulting in the production of bacteriocins.This review aims at describing the types of signal molecules,signal transduction mechanism and the regulation of quorum sensing in bacteriocins synthesis of LAB and understanding the regulation mechanism of quorum sensing involved in the production of two classes of bacteriocin in LAB.%许多乳酸菌能够产生抗菌活性肽——细菌素,细菌素具有不同的结构、作用方式、抑菌谱和效价,通常认为乳酸菌和其所产的细菌素都是安全的,乳酸菌所产细菌素作为天然食品防腐剂已显示了巨大的潜能。基于群体感应的细胞间交流已成为细菌素合成的关键调控机制,群体感应作为细胞密度函数,可使细菌素产生保持同步性。群体感应需通过信号分子介导感知菌体密度,信号分子随着菌体密度增加而增加,并激活信号转导级联使菌体产生细菌素。本文通过对乳酸菌群体感应信号分子种类、信号转导机制及群体感应系统对两类细菌素合成的调控进行综述,以初步了解群体感

  3. Antimicrobial substances produced by coliform strains active against foodborne pathogens.

    Science.gov (United States)

    Fleming, Luana Rocha; Bolzan, Dayana Nascimento; Nascimento, Janaína Dos Santos

    2010-03-01

    In the present study, 31 coliform strains were isolated from salad, cheese, and meat products sold in commercial establishments in Rio de Janeiro city, and were tested for antibiotic resistance and antimicrobial substance production. Thirteen strains (41.9%) were resistant to at least one antibiotic tested, among which one presented resistance to nine different antibiotics. Two strains (6.4%) exhibited inhibitory activity against the indicator strains, Escherichia coli LMIFRJ and Salmonella enterica I. The antimicrobial substances that they produced were sensitive to proteolytic enzymes, suggesting that they might be bacteriocins. The producer strains were identified as Klebsiella ozaenae and Raoultella terrigena. Although they had similar spectrums of action, the bacteriocins were shown to be different. Both of them were able to inhibit E. coli, Klebsiella, Enterobacter, and Salmonella strains, including antibiotic-resistant ones. Our results suggest that these bacteriocins, named klebicin K and raoultellin L, could have potential use against some foodborne pathogens.

  4. Method for Rapid Purification of Class IIa Bacteriocins and Comparison of Their Activities

    OpenAIRE

    Guyonnet, D.; Fremaux, C; Cenatiempo, Y; Berjeaud, J. M.

    2000-01-01

    A three-step method was developed for the purification of mesentericin Y105 (60% yield) from the culture supernatant of Leuconostoc mesenteroides Y105. The same procedure was successfully applied to the purification of five other anti-Listeria bacteriocins identified by mass spectrometry. Specific activities of the purified bacteriocins were compared.

  5. Phage Tail-Like (High-Molecular-Weight) Bacteriocins of Budvicia aquatica and Pragia fontium (Enterobacteriaceae)

    OpenAIRE

    Šmarda, Jan; Benada, Oldřich

    2005-01-01

    Electron microscopic analysis of contractile phage tail-like bacteriocins of three Pragia fontium strains and one Budvicia aquatica strain was performed. Fonticin and aquaticin are remarkably heat sensitive but trypsin resistant. Simultaneous production of contractile and flexible phage tail-like bacteriocins in the P. fontium 64613 strain is shown for the first time.

  6. Sec-mediated secretion of bacteriocin enterocin P by Lactococcus lactis

    NARCIS (Netherlands)

    Herranz, C; Driessen, AJM

    2005-01-01

    Most lactic acid bacterium bacteriocins utilize specific leader peptides and dedicated machineries for secretion. In contrast, the enterococcal bacteriocin enterocin P (EntP) contains a typical signal peptide that directs its secretion when heterologously expressed in Lactococcus lactis. Signal pept

  7. Production, purification and characterization of bacteriocin from Lactobacillus murinus AU06 and its broad antibacterial spectrum

    Institute of Scientific and Technical Information of China (English)

    Sivaramasamy Elayaraja; Neelamegam Annamalai; Packiyam Mayavu; Thangavel Balasubramanian

    2014-01-01

    Objective: To study the production, purification and characterization of bacteriocin fromLactobacillus murinus against fish pathogens.Methods:AU06 isolated from marine sediments and its broad spectrum of inhibition bacteriocin. In addition, purified bacteriocin was tested for its antimicrobial activity against fish pathogens.Results:In the present study, the bacteriocin production was found to be higher at 35 °C, pH The selected strain was used in production, purification and characterized of 6.0 and was purified to 4.74 fold with 55. 38 U/mg of specific activity with the yield of 28.92%. The molecular weight of the purified bacteriocin was estimated as 21 kDa. The purified bacteriocin exhibited complete inactivation of antimicrobial activity when treated with proteinase K, pronase, chymotrypsin, trypsin, pepsin and papain. The purified bacteriocin exhibited broad inhibitory spectrum against both Gram positive and negative bacteria.Conclusions:It is concluded that the ability of bacteriocin in inhibiting a wide-range of pathogenic bacteria is of potential interest for food safety and may have future applications in food preservative.

  8. Circularity and Lambda Abstraction

    DEFF Research Database (Denmark)

    Danvy, Olivier; Thiemann, Peter; Zerny, Ian

    2013-01-01

    circular unknowns as dead variables, and we apply the functions to them. The result is a lazy circular program a la Bird. We illustrate the two transformations by mapping an algebraic construct to an isomorphic one with new leaves, reading a binary number as sug- gested by Knuth, and backpatching...

  9. Perfect Circular Dichroic Metamirrors

    CERN Document Server

    Wang, Zuojia; Liu, Yongmin

    2015-01-01

    In nature, the beetle Chrysina gloriosa derives its iridescence by selectively reflecting left-handed circularly polarized light only. Here, for the first time, we introduce and demonstrate the optical analogue based on an ultrathin metamaterial, which we term circular dichroic metamirror. A general method to design the circular dichroic metasmirror is presented under the framework of Jones calculus. It is analytically shown that the metamirror can be realized by two layers of anisotropic metamaterial structures, in order to satisfy the required simultaneous breakings of n-fold rotational (n>2) and mirror symmetries. We design an infrared metamirror, which shows perfect reflectance for left-handed circularly polarized light without reversing its handedness, while almost completely absorbs right-handed circularly polarized light. These findings offer new methodology to realize novel chiral optical devices for a variety of applications, including polarimetric imaging, molecular spectroscopy, as well as quantum ...

  10. Structure of the atypical bacteriocin pectocin M2 implies a novel mechanism of protein uptake.

    Science.gov (United States)

    Grinter, Rhys; Josts, Inokentijs; Zeth, Kornelius; Roszak, Aleksander W; McCaughey, Laura C; Cogdell, Richard J; Milner, Joel J; Kelly, Sharon M; Byron, Olwyn; Walker, Daniel

    2014-07-01

    The colicin-like bacteriocins are potent protein antibiotics that have evolved to efficiently cross the outer membrane of Gram-negative bacteria by parasitizing nutrient uptake systems. We have structurally characterized the colicin M-like bacteriocin, pectocin M2, which is active against strains of Pectobacterium spp. This unusual bacteriocin lacks the intrinsically unstructured translocation domain that usually mediates translocation of these bacteriocins across the outer membrane, containing only a single globular ferredoxin domain connected to its cytotoxic domain by a flexible α-helix, which allows it to adopt two distinct conformations in solution. The ferredoxin domain of pectocin M2 is homologous to plant ferredoxins and allows pectocin M2 to parasitize a system utilized by Pectobacterium to obtain iron during infection of plants. Furthermore, we identify a novel ferredoxin-containing bacteriocin pectocin P, which possesses a cytotoxic domain homologous to lysozyme, illustrating that the ferredoxin domain acts as a generic delivery module for cytotoxic domains in Pectobacterium.

  11. Complete genome sequence of Enterococcus mundtii QU 25, an efficient L-(+)-lactic acid-producing bacterium.

    Science.gov (United States)

    Shiwa, Yuh; Yanase, Hiroaki; Hirose, Yuu; Satomi, Shohei; Araya-Kojima, Tomoko; Watanabe, Satoru; Zendo, Takeshi; Chibazakura, Taku; Shimizu-Kadota, Mariko; Yoshikawa, Hirofumi; Sonomoto, Kenji

    2014-08-01

    Enterococcus mundtii QU 25, a non-dairy bacterial strain of ovine faecal origin, can ferment both cellobiose and xylose to produce l-lactic acid. The use of this strain is highly desirable for economical l-lactate production from renewable biomass substrates. Genome sequence determination is necessary for the genetic improvement of this strain. We report the complete genome sequence of strain QU 25, primarily determined using Pacific Biosciences sequencing technology. The E. mundtii QU 25 genome comprises a 3 022 186-bp single circular chromosome (GC content, 38.6%) and five circular plasmids: pQY182, pQY082, pQY039, pQY024, and pQY003. In all, 2900 protein-coding sequences, 63 tRNA genes, and 6 rRNA operons were predicted in the QU 25 chromosome. Plasmid pQY024 harbours genes for mundticin production. We found that strain QU 25 produces a bacteriocin, suggesting that mundticin-encoded genes on plasmid pQY024 were functional. For lactic acid fermentation, two gene clusters were identified-one involved in the initial metabolism of xylose and uptake of pentose and the second containing genes for the pentose phosphate pathway and uptake of related sugars. This is the first complete genome sequence of an E. mundtii strain. The data provide insights into lactate production in this bacterium and its evolution among enterococci.

  12. 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.

  13. 细菌素及其在动物生产中的应用%Bacteriocins and Their Application in Animal Production

    Institute of Scientific and Technical Information of China (English)

    朱双; 张爱忠; 姜宁; 任文; 蔡鹏; 王法明; 穆洋; 王立学; 张欣鑫

    2014-01-01

    Due to the emergence of antibiotic-resistant pathogens, some infectious diseases are difficult to treat and are getting worse.In recent years, the development of new and effective antibiotics is slow.However, the alternative antibiotics bacteria are concerned in recent years, which have a great potential to inhibit antibiotic-resistant pathogens by bacteriocins.Bacteriocins are small antimicrobial peptides ( AMPS) which are produced by many bacteria, they not only can inhibit effectively pathogen growth, but also can play an important role in health care as probiotics.At the same time, bacteriocins have been commonly used as a preservative in food production.With the focus on health and safety of livestock products as well as popularization and application of probiotics in diet increasing, bacteriocins will be widely used in animal production.This review summarizes the concept, classification, mechanism of bacteriocins, and discusses present research progress about the appli-cation of bacteriocins in animal production.%由于抗生素耐药病原菌的出现,一些传染性疾病已难以治疗并且日益恶化。近年来开发新的和有效的抗生素进展缓慢。然而,可替代抗生素的细菌素近些年来备受关注,其在控制抗生素耐药病原菌上拥有巨大的潜力。细菌素是由许多细菌产生的小抗菌肽( AMPs),不仅可以有效地抑制病原体生长,还可以作为益生菌在医疗中发挥重要作用。同时,细菌素作为防腐剂在食品生产中普遍应用,随着人们对畜产品卫生与安全的关注以及益生菌在饲料中的推广应用,细菌素在动物生产中也有着非常广阔的应用前景。为此,本文旨在在介绍细菌素的概念、分类、作用机制的基础上,进一步介绍细菌素在动物生产上的应用。

  14. High-level resistance to class IIa bacteriocins is associated with one general mechanism in Listeria monocytogenes.

    Science.gov (United States)

    Gravesen, Anne; Ramnath, Manilduth; Rechinger, K Björn; Andersen, Natalie; Jänsch, Lothar; Héchard, Yann; Hastings, John W; Knøchel, Susanne

    2002-08-01

    Class IIa bacteriocins may be used as natural food preservatives, yet resistance development in the target organisms is still poorly understood. In this study, the understanding of class IIa resistance development in Listeria monocytogenes is extended, linking the seemingly diverging results previously reported. Eight resistant mutants having a high resistance level (at least a 10(3)-fold increase in MIC), originating from five wild-type listerial strains, were independently isolated following exposure to four different class IIa bacteriocin-producing lactic acid bacteria (including pediocin PA-1 and leucocin A producers). Two of the mutants were isolated from food model systems (a saveloy-type sausage at 10 degrees C, and salmon juice at 5 degrees C). Northern blot analysis showed that the eight mutants all had increased expression of EII(Bgl) and a phospho-beta-glucosidase homologue, both originating from putative beta-glucoside-specific phosphoenolpyruvate-dependent phosphotransferase systems (PTSs). However, disruption of these genes in a resistant mutant did not confer pediocin sensitivity. Comparative two-dimensional gel analysis of proteins isolated from mutant and wild-type strains showed that one spot was consistently missing in the gels from mutant strains. This spot corresponded to the MptA subunit of the mannose-specific PTS, found only in the gels of wild-type strains. The mptACD operon was recently shown to be regulated by the sigma(54) transcription factor in conjunction with the activator ManR. Class IIa bacteriocin-resistant mutants having defined mutations in mpt or manR also exhibited the two diverging PTS expression changes. It is suggested here that high-level class IIa resistance in L. monocytogenes and at least some other Gram-positive bacteria is developed by one prevalent mechanism, irrespective of wild-type strain, class IIa bacteriocin, or the tested environmental conditions. The changes in expression of the beta-glucoside-specific and

  15. Circular-Arc Cartograms

    CERN Document Server

    Kämper, Jan-Hinrich; Nöllenburg, Martin

    2011-01-01

    We present a new circular-arc cartogram model in which countries are drawn with circular arcs instead of straight-line segments. Given a geographic map and values associated with each country in the map, the cartogram is a new map in which the areas of the countries represent the corresponding values. In the circular-arc cartogram model straight-line segments can be replaced with circular arcs in order to achieve the desired areas, while the corners of the polygons defining each country remain fixed. The countries in circular-arc cartograms have the aesthetically pleasing appearance of clouds or snowflakes, depending on whether their edges are bent outwards or inwards. This makes is easy to determine whether a country has grown or shrunk, just by its overall shape. We show that determining whether a given map and area-values can be realized with a circular-arc cartogram is an NP-hard problem. Next we describe a heuristic method for constructing circular-arc cartograms, which uses a max-flow computation on the...

  16. Circular statistics in R

    CERN Document Server

    Pewsey, Arthur; Ruxton, Graeme D

    2013-01-01

    Circular Statistics in R provides the most comprehensive guide to the analysis of circular data in over a decade. Circular data arise in many scientific contexts whether it be angular directions such as: observed compass directions of departure of radio-collared migratory birds from a release point; bond angles measured in different molecules; wind directions at different times of year at a wind farm; direction of stress-fractures in concretebridge supports; longitudes of earthquake epicentres or seasonal and daily activity patterns, for example: data on the times of day at which animals are c

  17. Building a Circular Future

    DEFF Research Database (Denmark)

    Merrild, Heidi; Guldager Jensen, Kasper; Sommer, John

    2016-01-01

    of the circular strategies is not only in the future. Increased flexibility, optimized operation and maintenance, as well as a healthier building, is low-hanging fruit that can be harvested today. The project’s principles can be implemented in industrialized construction in a large scale today. That is proven......Natural resources are scarce and construction accounts for 40 percent of the material and energy consumption in Europe. This means that a switch to a circular future is necessary. ’Building a Circular Future’ maps out where we are, where we are going, and what is needed for this conversion to take...

  18. 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.

  19. Pediocin PA-1 and a pediocin producing Lactobacillus plantarum strain do not change the HMA rat microbiota

    DEFF Research Database (Denmark)

    Bernbom, Nete; Jelle, N.B.; Brogren, C.-H.

    2009-01-01

    The bacteriocin pediocin PA-1 has potential use as a food biopreservative, and understanding its effect on the commensal gut microbiota is important for assessment of consumer risks associated with the use of biopreservative cultures. Effects of ingested (i) pediocin PA-1 producing Lactobacillus...... in the faeces after ingestion. Pediocin PA-1 did not mediate changes of the rat microbiota, and a biological assay indicated that the bacteriocin was degraded or inactivated during passage through the intestine....

  20. Administrative & Operational Circulars - Reminder

    CERN Multimedia

    HR Department

    2011-01-01

    All Administrative and Operational Circulars are available on the intranet site of the Human Resources Department at the following address: http://cern.ch/hr-docs/admincirc/admincirc.asp Department Head Office